diff options
Diffstat (limited to 'drivers/dma/sh')
| -rw-r--r-- | drivers/dma/sh/Kconfig | 58 | ||||
| -rw-r--r-- | drivers/dma/sh/Makefile | 18 | ||||
| -rw-r--r-- | drivers/dma/sh/rcar-dmac.c | 2052 | ||||
| -rw-r--r-- | drivers/dma/sh/rz-dmac.c | 1003 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma-arm.h | 48 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 1052 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma.h | 61 | ||||
| -rw-r--r-- | drivers/dma/sh/shdmac.c | 938 | ||||
| -rw-r--r-- | drivers/dma/sh/usb-dmac.c | 914 |
9 files changed, 6144 insertions, 0 deletions
diff --git a/drivers/dma/sh/Kconfig b/drivers/dma/sh/Kconfig new file mode 100644 index 000000000..c0b2997ab --- /dev/null +++ b/drivers/dma/sh/Kconfig @@ -0,0 +1,58 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# DMA engine configuration for sh +# + +config RENESAS_DMA + bool + select DMA_ENGINE + +# +# DMA Engine Helpers +# + +config SH_DMAE_BASE + bool "Renesas SuperH DMA Engine support" + depends on SUPERH || COMPILE_TEST + depends on !SUPERH || SH_DMA + depends on !SH_DMA_API + default y + select RENESAS_DMA + help + Enable support for the Renesas SuperH DMA controllers. + +# +# DMA Controllers +# + +config SH_DMAE + tristate "Renesas SuperH DMAC support" + depends on SH_DMAE_BASE + help + Enable support for the Renesas SuperH DMA controllers. + +config RCAR_DMAC + tristate "Renesas R-Car Gen{2,3} and RZ/G{1,2} DMA Controller" + depends on ARCH_RENESAS || COMPILE_TEST + select RENESAS_DMA + help + This driver supports the general purpose DMA controller found in the + Renesas R-Car Gen{2,3} and RZ/G{1,2} SoCs. + +config RENESAS_USB_DMAC + tristate "Renesas USB-DMA Controller" + depends on ARCH_RENESAS || COMPILE_TEST + select RENESAS_DMA + select DMA_VIRTUAL_CHANNELS + help + This driver supports the USB-DMA controller found in the Renesas + SoCs. + +config RZ_DMAC + tristate "Renesas RZ/{G2L,V2L} DMA Controller" + depends on ARCH_RZG2L || COMPILE_TEST + select RENESAS_DMA + select DMA_VIRTUAL_CHANNELS + help + This driver supports the general purpose DMA controller found in the + Renesas RZ/{G2L,V2L} SoC variants. diff --git a/drivers/dma/sh/Makefile b/drivers/dma/sh/Makefile new file mode 100644 index 000000000..360ab6d25 --- /dev/null +++ b/drivers/dma/sh/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# DMA Engine Helpers +# + +obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o + +# +# DMA Controllers +# + +shdma-y := shdmac.o +shdma-objs := $(shdma-y) +obj-$(CONFIG_SH_DMAE) += shdma.o + +obj-$(CONFIG_RCAR_DMAC) += rcar-dmac.o +obj-$(CONFIG_RENESAS_USB_DMAC) += usb-dmac.o +obj-$(CONFIG_RZ_DMAC) += rz-dmac.o diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c new file mode 100644 index 000000000..641d689d1 --- /dev/null +++ b/drivers/dma/sh/rcar-dmac.c @@ -0,0 +1,2052 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas R-Car Gen2/Gen3 DMA Controller Driver + * + * Copyright (C) 2014-2019 Renesas Electronics Inc. + * + * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> + */ + +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "../dmaengine.h" + +/* + * struct rcar_dmac_xfer_chunk - Descriptor for a hardware transfer + * @node: entry in the parent's chunks list + * @src_addr: device source address + * @dst_addr: device destination address + * @size: transfer size in bytes + */ +struct rcar_dmac_xfer_chunk { + struct list_head node; + + dma_addr_t src_addr; + dma_addr_t dst_addr; + u32 size; +}; + +/* + * struct rcar_dmac_hw_desc - Hardware descriptor for a transfer chunk + * @sar: value of the SAR register (source address) + * @dar: value of the DAR register (destination address) + * @tcr: value of the TCR register (transfer count) + */ +struct rcar_dmac_hw_desc { + u32 sar; + u32 dar; + u32 tcr; + u32 reserved; +} __attribute__((__packed__)); + +/* + * struct rcar_dmac_desc - R-Car Gen2 DMA Transfer Descriptor + * @async_tx: base DMA asynchronous transaction descriptor + * @direction: direction of the DMA transfer + * @xfer_shift: log2 of the transfer size + * @chcr: value of the channel configuration register for this transfer + * @node: entry in the channel's descriptors lists + * @chunks: list of transfer chunks for this transfer + * @running: the transfer chunk being currently processed + * @nchunks: number of transfer chunks for this transfer + * @hwdescs.use: whether the transfer descriptor uses hardware descriptors + * @hwdescs.mem: hardware descriptors memory for the transfer + * @hwdescs.dma: device address of the hardware descriptors memory + * @hwdescs.size: size of the hardware descriptors in bytes + * @size: transfer size in bytes + * @cyclic: when set indicates that the DMA transfer is cyclic + */ +struct rcar_dmac_desc { + struct dma_async_tx_descriptor async_tx; + enum dma_transfer_direction direction; + unsigned int xfer_shift; + u32 chcr; + + struct list_head node; + struct list_head chunks; + struct rcar_dmac_xfer_chunk *running; + unsigned int nchunks; + + struct { + bool use; + struct rcar_dmac_hw_desc *mem; + dma_addr_t dma; + size_t size; + } hwdescs; + + unsigned int size; + bool cyclic; +}; + +#define to_rcar_dmac_desc(d) container_of(d, struct rcar_dmac_desc, async_tx) + +/* + * struct rcar_dmac_desc_page - One page worth of descriptors + * @node: entry in the channel's pages list + * @descs: array of DMA descriptors + * @chunks: array of transfer chunk descriptors + */ +struct rcar_dmac_desc_page { + struct list_head node; + + union { + DECLARE_FLEX_ARRAY(struct rcar_dmac_desc, descs); + DECLARE_FLEX_ARRAY(struct rcar_dmac_xfer_chunk, chunks); + }; +}; + +#define RCAR_DMAC_DESCS_PER_PAGE \ + ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, descs)) / \ + sizeof(struct rcar_dmac_desc)) +#define RCAR_DMAC_XFER_CHUNKS_PER_PAGE \ + ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, chunks)) / \ + sizeof(struct rcar_dmac_xfer_chunk)) + +/* + * struct rcar_dmac_chan_slave - Slave configuration + * @slave_addr: slave memory address + * @xfer_size: size (in bytes) of hardware transfers + */ +struct rcar_dmac_chan_slave { + phys_addr_t slave_addr; + unsigned int xfer_size; +}; + +/* + * struct rcar_dmac_chan_map - Map of slave device phys to dma address + * @addr: slave dma address + * @dir: direction of mapping + * @slave: slave configuration that is mapped + */ +struct rcar_dmac_chan_map { + dma_addr_t addr; + enum dma_data_direction dir; + struct rcar_dmac_chan_slave slave; +}; + +/* + * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel + * @chan: base DMA channel object + * @iomem: channel I/O memory base + * @index: index of this channel in the controller + * @irq: channel IRQ + * @src: slave memory address and size on the source side + * @dst: slave memory address and size on the destination side + * @mid_rid: hardware MID/RID for the DMA client using this channel + * @lock: protects the channel CHCR register and the desc members + * @desc.free: list of free descriptors + * @desc.pending: list of pending descriptors (submitted with tx_submit) + * @desc.active: list of active descriptors (activated with issue_pending) + * @desc.done: list of completed descriptors + * @desc.wait: list of descriptors waiting for an ack + * @desc.running: the descriptor being processed (a member of the active list) + * @desc.chunks_free: list of free transfer chunk descriptors + * @desc.pages: list of pages used by allocated descriptors + */ +struct rcar_dmac_chan { + struct dma_chan chan; + void __iomem *iomem; + unsigned int index; + int irq; + + struct rcar_dmac_chan_slave src; + struct rcar_dmac_chan_slave dst; + struct rcar_dmac_chan_map map; + int mid_rid; + + spinlock_t lock; + + struct { + struct list_head free; + struct list_head pending; + struct list_head active; + struct list_head done; + struct list_head wait; + struct rcar_dmac_desc *running; + + struct list_head chunks_free; + + struct list_head pages; + } desc; +}; + +#define to_rcar_dmac_chan(c) container_of(c, struct rcar_dmac_chan, chan) + +/* + * struct rcar_dmac - R-Car Gen2 DMA Controller + * @engine: base DMA engine object + * @dev: the hardware device + * @dmac_base: remapped base register block + * @chan_base: remapped channel register block (optional) + * @n_channels: number of available channels + * @channels: array of DMAC channels + * @channels_mask: bitfield of which DMA channels are managed by this driver + * @modules: bitmask of client modules in use + */ +struct rcar_dmac { + struct dma_device engine; + struct device *dev; + void __iomem *dmac_base; + void __iomem *chan_base; + + unsigned int n_channels; + struct rcar_dmac_chan *channels; + u32 channels_mask; + + DECLARE_BITMAP(modules, 256); +}; + +#define to_rcar_dmac(d) container_of(d, struct rcar_dmac, engine) + +#define for_each_rcar_dmac_chan(i, dmac, chan) \ + for (i = 0, chan = &(dmac)->channels[0]; i < (dmac)->n_channels; i++, chan++) \ + if (!((dmac)->channels_mask & BIT(i))) continue; else + +/* + * struct rcar_dmac_of_data - This driver's OF data + * @chan_offset_base: DMAC channels base offset + * @chan_offset_stride: DMAC channels offset stride + */ +struct rcar_dmac_of_data { + u32 chan_offset_base; + u32 chan_offset_stride; +}; + +/* ----------------------------------------------------------------------------- + * Registers + */ + +#define RCAR_DMAISTA 0x0020 +#define RCAR_DMASEC 0x0030 +#define RCAR_DMAOR 0x0060 +#define RCAR_DMAOR_PRI_FIXED (0 << 8) +#define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8) +#define RCAR_DMAOR_AE (1 << 2) +#define RCAR_DMAOR_DME (1 << 0) +#define RCAR_DMACHCLR 0x0080 /* Not on R-Car Gen4 */ +#define RCAR_DMADPSEC 0x00a0 + +#define RCAR_DMASAR 0x0000 +#define RCAR_DMADAR 0x0004 +#define RCAR_DMATCR 0x0008 +#define RCAR_DMATCR_MASK 0x00ffffff +#define RCAR_DMATSR 0x0028 +#define RCAR_DMACHCR 0x000c +#define RCAR_DMACHCR_CAE (1 << 31) +#define RCAR_DMACHCR_CAIE (1 << 30) +#define RCAR_DMACHCR_DPM_DISABLED (0 << 28) +#define RCAR_DMACHCR_DPM_ENABLED (1 << 28) +#define RCAR_DMACHCR_DPM_REPEAT (2 << 28) +#define RCAR_DMACHCR_DPM_INFINITE (3 << 28) +#define RCAR_DMACHCR_RPT_SAR (1 << 27) +#define RCAR_DMACHCR_RPT_DAR (1 << 26) +#define RCAR_DMACHCR_RPT_TCR (1 << 25) +#define RCAR_DMACHCR_DPB (1 << 22) +#define RCAR_DMACHCR_DSE (1 << 19) +#define RCAR_DMACHCR_DSIE (1 << 18) +#define RCAR_DMACHCR_TS_1B ((0 << 20) | (0 << 3)) +#define RCAR_DMACHCR_TS_2B ((0 << 20) | (1 << 3)) +#define RCAR_DMACHCR_TS_4B ((0 << 20) | (2 << 3)) +#define RCAR_DMACHCR_TS_16B ((0 << 20) | (3 << 3)) +#define RCAR_DMACHCR_TS_32B ((1 << 20) | (0 << 3)) +#define RCAR_DMACHCR_TS_64B ((1 << 20) | (1 << 3)) +#define RCAR_DMACHCR_TS_8B ((1 << 20) | (3 << 3)) +#define RCAR_DMACHCR_DM_FIXED (0 << 14) +#define RCAR_DMACHCR_DM_INC (1 << 14) +#define RCAR_DMACHCR_DM_DEC (2 << 14) +#define RCAR_DMACHCR_SM_FIXED (0 << 12) +#define RCAR_DMACHCR_SM_INC (1 << 12) +#define RCAR_DMACHCR_SM_DEC (2 << 12) +#define RCAR_DMACHCR_RS_AUTO (4 << 8) +#define RCAR_DMACHCR_RS_DMARS (8 << 8) +#define RCAR_DMACHCR_IE (1 << 2) +#define RCAR_DMACHCR_TE (1 << 1) +#define RCAR_DMACHCR_DE (1 << 0) +#define RCAR_DMATCRB 0x0018 +#define RCAR_DMATSRB 0x0038 +#define RCAR_DMACHCRB 0x001c +#define RCAR_DMACHCRB_DCNT(n) ((n) << 24) +#define RCAR_DMACHCRB_DPTR_MASK (0xff << 16) +#define RCAR_DMACHCRB_DPTR_SHIFT 16 +#define RCAR_DMACHCRB_DRST (1 << 15) +#define RCAR_DMACHCRB_DTS (1 << 8) +#define RCAR_DMACHCRB_SLM_NORMAL (0 << 4) +#define RCAR_DMACHCRB_SLM_CLK(n) ((8 | (n)) << 4) +#define RCAR_DMACHCRB_PRI(n) ((n) << 0) +#define RCAR_DMARS 0x0040 +#define RCAR_DMABUFCR 0x0048 +#define RCAR_DMABUFCR_MBU(n) ((n) << 16) +#define RCAR_DMABUFCR_ULB(n) ((n) << 0) +#define RCAR_DMADPBASE 0x0050 +#define RCAR_DMADPBASE_MASK 0xfffffff0 +#define RCAR_DMADPBASE_SEL (1 << 0) +#define RCAR_DMADPCR 0x0054 +#define RCAR_DMADPCR_DIPT(n) ((n) << 24) +#define RCAR_DMAFIXSAR 0x0010 +#define RCAR_DMAFIXDAR 0x0014 +#define RCAR_DMAFIXDPBASE 0x0060 + +/* For R-Car Gen4 */ +#define RCAR_GEN4_DMACHCLR 0x0100 + +/* Hardcode the MEMCPY transfer size to 4 bytes. */ +#define RCAR_DMAC_MEMCPY_XFER_SIZE 4 + +/* ----------------------------------------------------------------------------- + * Device access + */ + +static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data) +{ + if (reg == RCAR_DMAOR) + writew(data, dmac->dmac_base + reg); + else + writel(data, dmac->dmac_base + reg); +} + +static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg) +{ + if (reg == RCAR_DMAOR) + return readw(dmac->dmac_base + reg); + else + return readl(dmac->dmac_base + reg); +} + +static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg) +{ + if (reg == RCAR_DMARS) + return readw(chan->iomem + reg); + else + return readl(chan->iomem + reg); +} + +static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data) +{ + if (reg == RCAR_DMARS) + writew(data, chan->iomem + reg); + else + writel(data, chan->iomem + reg); +} + +static void rcar_dmac_chan_clear(struct rcar_dmac *dmac, + struct rcar_dmac_chan *chan) +{ + if (dmac->chan_base) + rcar_dmac_chan_write(chan, RCAR_GEN4_DMACHCLR, 1); + else + rcar_dmac_write(dmac, RCAR_DMACHCLR, BIT(chan->index)); +} + +static void rcar_dmac_chan_clear_all(struct rcar_dmac *dmac) +{ + struct rcar_dmac_chan *chan; + unsigned int i; + + if (dmac->chan_base) { + for_each_rcar_dmac_chan(i, dmac, chan) + rcar_dmac_chan_write(chan, RCAR_GEN4_DMACHCLR, 1); + } else { + rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask); + } +} + +/* ----------------------------------------------------------------------------- + * Initialization and configuration + */ + +static bool rcar_dmac_chan_is_busy(struct rcar_dmac_chan *chan) +{ + u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); + + return !!(chcr & (RCAR_DMACHCR_DE | RCAR_DMACHCR_TE)); +} + +static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc = chan->desc.running; + u32 chcr = desc->chcr; + + WARN_ON_ONCE(rcar_dmac_chan_is_busy(chan)); + + if (chan->mid_rid >= 0) + rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid); + + if (desc->hwdescs.use) { + struct rcar_dmac_xfer_chunk *chunk = + list_first_entry(&desc->chunks, + struct rcar_dmac_xfer_chunk, node); + + dev_dbg(chan->chan.device->dev, + "chan%u: queue desc %p: %u@%pad\n", + chan->index, desc, desc->nchunks, &desc->hwdescs.dma); + +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, + chunk->src_addr >> 32); + rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, + chunk->dst_addr >> 32); + rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE, + desc->hwdescs.dma >> 32); +#endif + rcar_dmac_chan_write(chan, RCAR_DMADPBASE, + (desc->hwdescs.dma & 0xfffffff0) | + RCAR_DMADPBASE_SEL); + rcar_dmac_chan_write(chan, RCAR_DMACHCRB, + RCAR_DMACHCRB_DCNT(desc->nchunks - 1) | + RCAR_DMACHCRB_DRST); + + /* + * Errata: When descriptor memory is accessed through an IOMMU + * the DMADAR register isn't initialized automatically from the + * first descriptor at beginning of transfer by the DMAC like it + * should. Initialize it manually with the destination address + * of the first chunk. + */ + rcar_dmac_chan_write(chan, RCAR_DMADAR, + chunk->dst_addr & 0xffffffff); + + /* + * Program the descriptor stage interrupt to occur after the end + * of the first stage. + */ + rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(1)); + + chcr |= RCAR_DMACHCR_RPT_SAR | RCAR_DMACHCR_RPT_DAR + | RCAR_DMACHCR_RPT_TCR | RCAR_DMACHCR_DPB; + + /* + * If the descriptor isn't cyclic enable normal descriptor mode + * and the transfer completion interrupt. + */ + if (!desc->cyclic) + chcr |= RCAR_DMACHCR_DPM_ENABLED | RCAR_DMACHCR_IE; + /* + * If the descriptor is cyclic and has a callback enable the + * descriptor stage interrupt in infinite repeat mode. + */ + else if (desc->async_tx.callback) + chcr |= RCAR_DMACHCR_DPM_INFINITE | RCAR_DMACHCR_DSIE; + /* + * Otherwise just select infinite repeat mode without any + * interrupt. + */ + else + chcr |= RCAR_DMACHCR_DPM_INFINITE; + } else { + struct rcar_dmac_xfer_chunk *chunk = desc->running; + + dev_dbg(chan->chan.device->dev, + "chan%u: queue chunk %p: %u@%pad -> %pad\n", + chan->index, chunk, chunk->size, &chunk->src_addr, + &chunk->dst_addr); + +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, + chunk->src_addr >> 32); + rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, + chunk->dst_addr >> 32); +#endif + rcar_dmac_chan_write(chan, RCAR_DMASAR, + chunk->src_addr & 0xffffffff); + rcar_dmac_chan_write(chan, RCAR_DMADAR, + chunk->dst_addr & 0xffffffff); + rcar_dmac_chan_write(chan, RCAR_DMATCR, + chunk->size >> desc->xfer_shift); + + chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE; + } + + rcar_dmac_chan_write(chan, RCAR_DMACHCR, + chcr | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAIE); +} + +static int rcar_dmac_init(struct rcar_dmac *dmac) +{ + u16 dmaor; + + /* Clear all channels and enable the DMAC globally. */ + rcar_dmac_chan_clear_all(dmac); + rcar_dmac_write(dmac, RCAR_DMAOR, + RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME); + + dmaor = rcar_dmac_read(dmac, RCAR_DMAOR); + if ((dmaor & (RCAR_DMAOR_AE | RCAR_DMAOR_DME)) != RCAR_DMAOR_DME) { + dev_warn(dmac->dev, "DMAOR initialization failed.\n"); + return -EIO; + } + + return 0; +} + +/* ----------------------------------------------------------------------------- + * Descriptors submission + */ + +static dma_cookie_t rcar_dmac_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct rcar_dmac_chan *chan = to_rcar_dmac_chan(tx->chan); + struct rcar_dmac_desc *desc = to_rcar_dmac_desc(tx); + unsigned long flags; + dma_cookie_t cookie; + + spin_lock_irqsave(&chan->lock, flags); + + cookie = dma_cookie_assign(tx); + + dev_dbg(chan->chan.device->dev, "chan%u: submit #%d@%p\n", + chan->index, tx->cookie, desc); + + list_add_tail(&desc->node, &chan->desc.pending); + desc->running = list_first_entry(&desc->chunks, + struct rcar_dmac_xfer_chunk, node); + + spin_unlock_irqrestore(&chan->lock, flags); + + return cookie; +} + +/* ----------------------------------------------------------------------------- + * Descriptors allocation and free + */ + +/* + * rcar_dmac_desc_alloc - Allocate a page worth of DMA descriptors + * @chan: the DMA channel + * @gfp: allocation flags + */ +static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) +{ + struct rcar_dmac_desc_page *page; + unsigned long flags; + LIST_HEAD(list); + unsigned int i; + + page = (void *)get_zeroed_page(gfp); + if (!page) + return -ENOMEM; + + for (i = 0; i < RCAR_DMAC_DESCS_PER_PAGE; ++i) { + struct rcar_dmac_desc *desc = &page->descs[i]; + + dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan); + desc->async_tx.tx_submit = rcar_dmac_tx_submit; + INIT_LIST_HEAD(&desc->chunks); + + list_add_tail(&desc->node, &list); + } + + spin_lock_irqsave(&chan->lock, flags); + list_splice_tail(&list, &chan->desc.free); + list_add_tail(&page->node, &chan->desc.pages); + spin_unlock_irqrestore(&chan->lock, flags); + + return 0; +} + +/* + * rcar_dmac_desc_put - Release a DMA transfer descriptor + * @chan: the DMA channel + * @desc: the descriptor + * + * Put the descriptor and its transfer chunk descriptors back in the channel's + * free descriptors lists. The descriptor's chunks list will be reinitialized to + * an empty list as a result. + * + * The descriptor must have been removed from the channel's lists before calling + * this function. + */ +static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc) +{ + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free); + list_add(&desc->node, &chan->desc.free); + spin_unlock_irqrestore(&chan->lock, flags); +} + +static void rcar_dmac_desc_recycle_acked(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc, *_desc; + unsigned long flags; + LIST_HEAD(list); + + /* + * We have to temporarily move all descriptors from the wait list to a + * local list as iterating over the wait list, even with + * list_for_each_entry_safe, isn't safe if we release the channel lock + * around the rcar_dmac_desc_put() call. + */ + spin_lock_irqsave(&chan->lock, flags); + list_splice_init(&chan->desc.wait, &list); + spin_unlock_irqrestore(&chan->lock, flags); + + list_for_each_entry_safe(desc, _desc, &list, node) { + if (async_tx_test_ack(&desc->async_tx)) { + list_del(&desc->node); + rcar_dmac_desc_put(chan, desc); + } + } + + if (list_empty(&list)) + return; + + /* Put the remaining descriptors back in the wait list. */ + spin_lock_irqsave(&chan->lock, flags); + list_splice(&list, &chan->desc.wait); + spin_unlock_irqrestore(&chan->lock, flags); +} + +/* + * rcar_dmac_desc_get - Allocate a descriptor for a DMA transfer + * @chan: the DMA channel + * + * Locking: This function must be called in a non-atomic context. + * + * Return: A pointer to the allocated descriptor or NULL if no descriptor can + * be allocated. + */ +static struct rcar_dmac_desc *rcar_dmac_desc_get(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc; + unsigned long flags; + int ret; + + /* Recycle acked descriptors before attempting allocation. */ + rcar_dmac_desc_recycle_acked(chan); + + spin_lock_irqsave(&chan->lock, flags); + + while (list_empty(&chan->desc.free)) { + /* + * No free descriptors, allocate a page worth of them and try + * again, as someone else could race us to get the newly + * allocated descriptors. If the allocation fails return an + * error. + */ + spin_unlock_irqrestore(&chan->lock, flags); + ret = rcar_dmac_desc_alloc(chan, GFP_NOWAIT); + if (ret < 0) + return NULL; + spin_lock_irqsave(&chan->lock, flags); + } + + desc = list_first_entry(&chan->desc.free, struct rcar_dmac_desc, node); + list_del(&desc->node); + + spin_unlock_irqrestore(&chan->lock, flags); + + return desc; +} + +/* + * rcar_dmac_xfer_chunk_alloc - Allocate a page worth of transfer chunks + * @chan: the DMA channel + * @gfp: allocation flags + */ +static int rcar_dmac_xfer_chunk_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) +{ + struct rcar_dmac_desc_page *page; + unsigned long flags; + LIST_HEAD(list); + unsigned int i; + + page = (void *)get_zeroed_page(gfp); + if (!page) + return -ENOMEM; + + for (i = 0; i < RCAR_DMAC_XFER_CHUNKS_PER_PAGE; ++i) { + struct rcar_dmac_xfer_chunk *chunk = &page->chunks[i]; + + list_add_tail(&chunk->node, &list); + } + + spin_lock_irqsave(&chan->lock, flags); + list_splice_tail(&list, &chan->desc.chunks_free); + list_add_tail(&page->node, &chan->desc.pages); + spin_unlock_irqrestore(&chan->lock, flags); + + return 0; +} + +/* + * rcar_dmac_xfer_chunk_get - Allocate a transfer chunk for a DMA transfer + * @chan: the DMA channel + * + * Locking: This function must be called in a non-atomic context. + * + * Return: A pointer to the allocated transfer chunk descriptor or NULL if no + * descriptor can be allocated. + */ +static struct rcar_dmac_xfer_chunk * +rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_xfer_chunk *chunk; + unsigned long flags; + int ret; + + spin_lock_irqsave(&chan->lock, flags); + + while (list_empty(&chan->desc.chunks_free)) { + /* + * No free descriptors, allocate a page worth of them and try + * again, as someone else could race us to get the newly + * allocated descriptors. If the allocation fails return an + * error. + */ + spin_unlock_irqrestore(&chan->lock, flags); + ret = rcar_dmac_xfer_chunk_alloc(chan, GFP_NOWAIT); + if (ret < 0) + return NULL; + spin_lock_irqsave(&chan->lock, flags); + } + + chunk = list_first_entry(&chan->desc.chunks_free, + struct rcar_dmac_xfer_chunk, node); + list_del(&chunk->node); + + spin_unlock_irqrestore(&chan->lock, flags); + + return chunk; +} + +static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc, size_t size) +{ + /* + * dma_alloc_coherent() allocates memory in page size increments. To + * avoid reallocating the hardware descriptors when the allocated size + * wouldn't change align the requested size to a multiple of the page + * size. + */ + size = PAGE_ALIGN(size); + + if (desc->hwdescs.size == size) + return; + + if (desc->hwdescs.mem) { + dma_free_coherent(chan->chan.device->dev, desc->hwdescs.size, + desc->hwdescs.mem, desc->hwdescs.dma); + desc->hwdescs.mem = NULL; + desc->hwdescs.size = 0; + } + + if (!size) + return; + + desc->hwdescs.mem = dma_alloc_coherent(chan->chan.device->dev, size, + &desc->hwdescs.dma, GFP_NOWAIT); + if (!desc->hwdescs.mem) + return; + + desc->hwdescs.size = size; +} + +static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc) +{ + struct rcar_dmac_xfer_chunk *chunk; + struct rcar_dmac_hw_desc *hwdesc; + + rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc)); + + hwdesc = desc->hwdescs.mem; + if (!hwdesc) + return -ENOMEM; + + list_for_each_entry(chunk, &desc->chunks, node) { + hwdesc->sar = chunk->src_addr; + hwdesc->dar = chunk->dst_addr; + hwdesc->tcr = chunk->size >> desc->xfer_shift; + hwdesc++; + } + + return 0; +} + +/* ----------------------------------------------------------------------------- + * Stop and reset + */ +static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan) +{ + u32 chcr; + unsigned int i; + + /* + * Ensure that the setting of the DE bit is actually 0 after + * clearing it. + */ + for (i = 0; i < 1024; i++) { + chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); + if (!(chcr & RCAR_DMACHCR_DE)) + return; + udelay(1); + } + + dev_err(chan->chan.device->dev, "CHCR DE check error\n"); +} + +static void rcar_dmac_clear_chcr_de(struct rcar_dmac_chan *chan) +{ + u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); + + /* set DE=0 and flush remaining data */ + rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE)); + + /* make sure all remaining data was flushed */ + rcar_dmac_chcr_de_barrier(chan); +} + +static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) +{ + u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); + + chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE | + RCAR_DMACHCR_TE | RCAR_DMACHCR_DE | + RCAR_DMACHCR_CAE | RCAR_DMACHCR_CAIE); + rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); + rcar_dmac_chcr_de_barrier(chan); +} + +static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc, *_desc; + unsigned long flags; + LIST_HEAD(descs); + + spin_lock_irqsave(&chan->lock, flags); + + /* Move all non-free descriptors to the local lists. */ + list_splice_init(&chan->desc.pending, &descs); + list_splice_init(&chan->desc.active, &descs); + list_splice_init(&chan->desc.done, &descs); + list_splice_init(&chan->desc.wait, &descs); + + chan->desc.running = NULL; + + spin_unlock_irqrestore(&chan->lock, flags); + + list_for_each_entry_safe(desc, _desc, &descs, node) { + list_del(&desc->node); + rcar_dmac_desc_put(chan, desc); + } +} + +static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac) +{ + struct rcar_dmac_chan *chan; + unsigned int i; + + /* Stop all channels. */ + for_each_rcar_dmac_chan(i, dmac, chan) { + /* Stop and reinitialize the channel. */ + spin_lock_irq(&chan->lock); + rcar_dmac_chan_halt(chan); + spin_unlock_irq(&chan->lock); + } +} + +static int rcar_dmac_chan_pause(struct dma_chan *chan) +{ + unsigned long flags; + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + + spin_lock_irqsave(&rchan->lock, flags); + rcar_dmac_clear_chcr_de(rchan); + spin_unlock_irqrestore(&rchan->lock, flags); + + return 0; +} + +/* ----------------------------------------------------------------------------- + * Descriptors preparation + */ + +static void rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc) +{ + static const u32 chcr_ts[] = { + RCAR_DMACHCR_TS_1B, RCAR_DMACHCR_TS_2B, + RCAR_DMACHCR_TS_4B, RCAR_DMACHCR_TS_8B, + RCAR_DMACHCR_TS_16B, RCAR_DMACHCR_TS_32B, + RCAR_DMACHCR_TS_64B, + }; + + unsigned int xfer_size; + u32 chcr; + + switch (desc->direction) { + case DMA_DEV_TO_MEM: + chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED + | RCAR_DMACHCR_RS_DMARS; + xfer_size = chan->src.xfer_size; + break; + + case DMA_MEM_TO_DEV: + chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC + | RCAR_DMACHCR_RS_DMARS; + xfer_size = chan->dst.xfer_size; + break; + + case DMA_MEM_TO_MEM: + default: + chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_INC + | RCAR_DMACHCR_RS_AUTO; + xfer_size = RCAR_DMAC_MEMCPY_XFER_SIZE; + break; + } + + desc->xfer_shift = ilog2(xfer_size); + desc->chcr = chcr | chcr_ts[desc->xfer_shift]; +} + +/* + * rcar_dmac_chan_prep_sg - prepare transfer descriptors from an SG list + * + * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also + * converted to scatter-gather to guarantee consistent locking and a correct + * list manipulation. For slave DMA direction carries the usual meaning, and, + * logically, the SG list is RAM and the addr variable contains slave address, + * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM + * and the SG list contains only one element and points at the source buffer. + */ +static struct dma_async_tx_descriptor * +rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, dma_addr_t dev_addr, + enum dma_transfer_direction dir, unsigned long dma_flags, + bool cyclic) +{ + struct rcar_dmac_xfer_chunk *chunk; + struct rcar_dmac_desc *desc; + struct scatterlist *sg; + unsigned int nchunks = 0; + unsigned int max_chunk_size; + unsigned int full_size = 0; + bool cross_boundary = false; + unsigned int i; +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + u32 high_dev_addr; + u32 high_mem_addr; +#endif + + desc = rcar_dmac_desc_get(chan); + if (!desc) + return NULL; + + desc->async_tx.flags = dma_flags; + desc->async_tx.cookie = -EBUSY; + + desc->cyclic = cyclic; + desc->direction = dir; + + rcar_dmac_chan_configure_desc(chan, desc); + + max_chunk_size = RCAR_DMATCR_MASK << desc->xfer_shift; + + /* + * Allocate and fill the transfer chunk descriptors. We own the only + * reference to the DMA descriptor, there's no need for locking. + */ + for_each_sg(sgl, sg, sg_len, i) { + dma_addr_t mem_addr = sg_dma_address(sg); + unsigned int len = sg_dma_len(sg); + + full_size += len; + +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + if (i == 0) { + high_dev_addr = dev_addr >> 32; + high_mem_addr = mem_addr >> 32; + } + + if ((dev_addr >> 32 != high_dev_addr) || + (mem_addr >> 32 != high_mem_addr)) + cross_boundary = true; +#endif + while (len) { + unsigned int size = min(len, max_chunk_size); + +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + /* + * Prevent individual transfers from crossing 4GB + * boundaries. + */ + if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) { + size = ALIGN(dev_addr, 1ULL << 32) - dev_addr; + cross_boundary = true; + } + if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) { + size = ALIGN(mem_addr, 1ULL << 32) - mem_addr; + cross_boundary = true; + } +#endif + + chunk = rcar_dmac_xfer_chunk_get(chan); + if (!chunk) { + rcar_dmac_desc_put(chan, desc); + return NULL; + } + + if (dir == DMA_DEV_TO_MEM) { + chunk->src_addr = dev_addr; + chunk->dst_addr = mem_addr; + } else { + chunk->src_addr = mem_addr; + chunk->dst_addr = dev_addr; + } + + chunk->size = size; + + dev_dbg(chan->chan.device->dev, + "chan%u: chunk %p/%p sgl %u@%p, %u/%u %pad -> %pad\n", + chan->index, chunk, desc, i, sg, size, len, + &chunk->src_addr, &chunk->dst_addr); + + mem_addr += size; + if (dir == DMA_MEM_TO_MEM) + dev_addr += size; + + len -= size; + + list_add_tail(&chunk->node, &desc->chunks); + nchunks++; + } + } + + desc->nchunks = nchunks; + desc->size = full_size; + + /* + * Use hardware descriptor lists if possible when more than one chunk + * needs to be transferred (otherwise they don't make much sense). + * + * Source/Destination address should be located in same 4GiB region + * in the 40bit address space when it uses Hardware descriptor, + * and cross_boundary is checking it. + */ + desc->hwdescs.use = !cross_boundary && nchunks > 1; + if (desc->hwdescs.use) { + if (rcar_dmac_fill_hwdesc(chan, desc) < 0) + desc->hwdescs.use = false; + } + + return &desc->async_tx; +} + +/* ----------------------------------------------------------------------------- + * DMA engine operations + */ + +static int rcar_dmac_alloc_chan_resources(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + int ret; + + INIT_LIST_HEAD(&rchan->desc.chunks_free); + INIT_LIST_HEAD(&rchan->desc.pages); + + /* Preallocate descriptors. */ + ret = rcar_dmac_xfer_chunk_alloc(rchan, GFP_KERNEL); + if (ret < 0) + return -ENOMEM; + + ret = rcar_dmac_desc_alloc(rchan, GFP_KERNEL); + if (ret < 0) + return -ENOMEM; + + return pm_runtime_get_sync(chan->device->dev); +} + +static void rcar_dmac_free_chan_resources(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + struct rcar_dmac *dmac = to_rcar_dmac(chan->device); + struct rcar_dmac_chan_map *map = &rchan->map; + struct rcar_dmac_desc_page *page, *_page; + struct rcar_dmac_desc *desc; + LIST_HEAD(list); + + /* Protect against ISR */ + spin_lock_irq(&rchan->lock); + rcar_dmac_chan_halt(rchan); + spin_unlock_irq(&rchan->lock); + + /* + * Now no new interrupts will occur, but one might already be + * running. Wait for it to finish before freeing resources. + */ + synchronize_irq(rchan->irq); + + if (rchan->mid_rid >= 0) { + /* The caller is holding dma_list_mutex */ + clear_bit(rchan->mid_rid, dmac->modules); + rchan->mid_rid = -EINVAL; + } + + list_splice_init(&rchan->desc.free, &list); + list_splice_init(&rchan->desc.pending, &list); + list_splice_init(&rchan->desc.active, &list); + list_splice_init(&rchan->desc.done, &list); + list_splice_init(&rchan->desc.wait, &list); + + rchan->desc.running = NULL; + + list_for_each_entry(desc, &list, node) + rcar_dmac_realloc_hwdesc(rchan, desc, 0); + + list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) { + list_del(&page->node); + free_page((unsigned long)page); + } + + /* Remove slave mapping if present. */ + if (map->slave.xfer_size) { + dma_unmap_resource(chan->device->dev, map->addr, + map->slave.xfer_size, map->dir, 0); + map->slave.xfer_size = 0; + } + + pm_runtime_put(chan->device->dev); +} + +static struct dma_async_tx_descriptor * +rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest, + dma_addr_t dma_src, size_t len, unsigned long flags) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + struct scatterlist sgl; + + if (!len) + return NULL; + + sg_init_table(&sgl, 1); + sg_set_page(&sgl, pfn_to_page(PFN_DOWN(dma_src)), len, + offset_in_page(dma_src)); + sg_dma_address(&sgl) = dma_src; + sg_dma_len(&sgl) = len; + + return rcar_dmac_chan_prep_sg(rchan, &sgl, 1, dma_dest, + DMA_MEM_TO_MEM, flags, false); +} + +static int rcar_dmac_map_slave_addr(struct dma_chan *chan, + enum dma_transfer_direction dir) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + struct rcar_dmac_chan_map *map = &rchan->map; + phys_addr_t dev_addr; + size_t dev_size; + enum dma_data_direction dev_dir; + + if (dir == DMA_DEV_TO_MEM) { + dev_addr = rchan->src.slave_addr; + dev_size = rchan->src.xfer_size; + dev_dir = DMA_TO_DEVICE; + } else { + dev_addr = rchan->dst.slave_addr; + dev_size = rchan->dst.xfer_size; + dev_dir = DMA_FROM_DEVICE; + } + + /* Reuse current map if possible. */ + if (dev_addr == map->slave.slave_addr && + dev_size == map->slave.xfer_size && + dev_dir == map->dir) + return 0; + + /* Remove old mapping if present. */ + if (map->slave.xfer_size) + dma_unmap_resource(chan->device->dev, map->addr, + map->slave.xfer_size, map->dir, 0); + map->slave.xfer_size = 0; + + /* Create new slave address map. */ + map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size, + dev_dir, 0); + + if (dma_mapping_error(chan->device->dev, map->addr)) { + dev_err(chan->device->dev, + "chan%u: failed to map %zx@%pap", rchan->index, + dev_size, &dev_addr); + return -EIO; + } + + dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n", + rchan->index, dev_size, &dev_addr, &map->addr, + dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE"); + + map->slave.slave_addr = dev_addr; + map->slave.xfer_size = dev_size; + map->dir = dev_dir; + + return 0; +} + +static struct dma_async_tx_descriptor * +rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction dir, + unsigned long flags, void *context) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + + /* Someone calling slave DMA on a generic channel? */ + if (rchan->mid_rid < 0 || !sg_len || !sg_dma_len(sgl)) { + dev_warn(chan->device->dev, + "%s: bad parameter: len=%d, id=%d\n", + __func__, sg_len, rchan->mid_rid); + return NULL; + } + + if (rcar_dmac_map_slave_addr(chan, dir)) + return NULL; + + return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, + dir, flags, false); +} + +#define RCAR_DMAC_MAX_SG_LEN 32 + +static struct dma_async_tx_descriptor * +rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, + size_t buf_len, size_t period_len, + enum dma_transfer_direction dir, unsigned long flags) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl; + unsigned int sg_len; + unsigned int i; + + /* Someone calling slave DMA on a generic channel? */ + if (rchan->mid_rid < 0 || buf_len < period_len) { + dev_warn(chan->device->dev, + "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", + __func__, buf_len, period_len, rchan->mid_rid); + return NULL; + } + + if (rcar_dmac_map_slave_addr(chan, dir)) + return NULL; + + sg_len = buf_len / period_len; + if (sg_len > RCAR_DMAC_MAX_SG_LEN) { + dev_err(chan->device->dev, + "chan%u: sg length %d exceeds limit %d", + rchan->index, sg_len, RCAR_DMAC_MAX_SG_LEN); + return NULL; + } + + /* + * Allocate the sg list dynamically as it would consume too much stack + * space. + */ + sgl = kmalloc_array(sg_len, sizeof(*sgl), GFP_NOWAIT); + if (!sgl) + return NULL; + + sg_init_table(sgl, sg_len); + + for (i = 0; i < sg_len; ++i) { + dma_addr_t src = buf_addr + (period_len * i); + + sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, + offset_in_page(src)); + sg_dma_address(&sgl[i]) = src; + sg_dma_len(&sgl[i]) = period_len; + } + + desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, + dir, flags, true); + + kfree(sgl); + return desc; +} + +static int rcar_dmac_device_config(struct dma_chan *chan, + struct dma_slave_config *cfg) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + + /* + * We could lock this, but you shouldn't be configuring the + * channel, while using it... + */ + rchan->src.slave_addr = cfg->src_addr; + rchan->dst.slave_addr = cfg->dst_addr; + rchan->src.xfer_size = cfg->src_addr_width; + rchan->dst.xfer_size = cfg->dst_addr_width; + + return 0; +} + +static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&rchan->lock, flags); + rcar_dmac_chan_halt(rchan); + spin_unlock_irqrestore(&rchan->lock, flags); + + /* + * FIXME: No new interrupt can occur now, but the IRQ thread might still + * be running. + */ + + rcar_dmac_chan_reinit(rchan); + + return 0; +} + +static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, + dma_cookie_t cookie) +{ + struct rcar_dmac_desc *desc = chan->desc.running; + struct rcar_dmac_xfer_chunk *running = NULL; + struct rcar_dmac_xfer_chunk *chunk; + enum dma_status status; + unsigned int residue = 0; + unsigned int dptr = 0; + unsigned int chcrb; + unsigned int tcrb; + unsigned int i; + + if (!desc) + return 0; + + /* + * If the cookie corresponds to a descriptor that has been completed + * there is no residue. The same check has already been performed by the + * caller but without holding the channel lock, so the descriptor could + * now be complete. + */ + status = dma_cookie_status(&chan->chan, cookie, NULL); + if (status == DMA_COMPLETE) + return 0; + + /* + * If the cookie doesn't correspond to the currently running transfer + * then the descriptor hasn't been processed yet, and the residue is + * equal to the full descriptor size. + * Also, a client driver is possible to call this function before + * rcar_dmac_isr_channel_thread() runs. In this case, the "desc.running" + * will be the next descriptor, and the done list will appear. So, if + * the argument cookie matches the done list's cookie, we can assume + * the residue is zero. + */ + if (cookie != desc->async_tx.cookie) { + list_for_each_entry(desc, &chan->desc.done, node) { + if (cookie == desc->async_tx.cookie) + return 0; + } + list_for_each_entry(desc, &chan->desc.pending, node) { + if (cookie == desc->async_tx.cookie) + return desc->size; + } + list_for_each_entry(desc, &chan->desc.active, node) { + if (cookie == desc->async_tx.cookie) + return desc->size; + } + + /* + * No descriptor found for the cookie, there's thus no residue. + * This shouldn't happen if the calling driver passes a correct + * cookie value. + */ + WARN(1, "No descriptor for cookie!"); + return 0; + } + + /* + * We need to read two registers. + * Make sure the control register does not skip to next chunk + * while reading the counter. + * Trying it 3 times should be enough: Initial read, retry, retry + * for the paranoid. + */ + for (i = 0; i < 3; i++) { + chcrb = rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & + RCAR_DMACHCRB_DPTR_MASK; + tcrb = rcar_dmac_chan_read(chan, RCAR_DMATCRB); + /* Still the same? */ + if (chcrb == (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & + RCAR_DMACHCRB_DPTR_MASK)) + break; + } + WARN_ONCE(i >= 3, "residue might be not continuous!"); + + /* + * In descriptor mode the descriptor running pointer is not maintained + * by the interrupt handler, find the running descriptor from the + * descriptor pointer field in the CHCRB register. In non-descriptor + * mode just use the running descriptor pointer. + */ + if (desc->hwdescs.use) { + dptr = chcrb >> RCAR_DMACHCRB_DPTR_SHIFT; + if (dptr == 0) + dptr = desc->nchunks; + dptr--; + WARN_ON(dptr >= desc->nchunks); + } else { + running = desc->running; + } + + /* Compute the size of all chunks still to be transferred. */ + list_for_each_entry_reverse(chunk, &desc->chunks, node) { + if (chunk == running || ++dptr == desc->nchunks) + break; + + residue += chunk->size; + } + + /* Add the residue for the current chunk. */ + residue += tcrb << desc->xfer_shift; + + return residue; +} + +static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + enum dma_status status; + unsigned long flags; + unsigned int residue; + bool cyclic; + + status = dma_cookie_status(chan, cookie, txstate); + if (status == DMA_COMPLETE || !txstate) + return status; + + spin_lock_irqsave(&rchan->lock, flags); + residue = rcar_dmac_chan_get_residue(rchan, cookie); + cyclic = rchan->desc.running ? rchan->desc.running->cyclic : false; + spin_unlock_irqrestore(&rchan->lock, flags); + + /* if there's no residue, the cookie is complete */ + if (!residue && !cyclic) + return DMA_COMPLETE; + + dma_set_residue(txstate, residue); + + return status; +} + +static void rcar_dmac_issue_pending(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&rchan->lock, flags); + + if (list_empty(&rchan->desc.pending)) + goto done; + + /* Append the pending list to the active list. */ + list_splice_tail_init(&rchan->desc.pending, &rchan->desc.active); + + /* + * If no transfer is running pick the first descriptor from the active + * list and start the transfer. + */ + if (!rchan->desc.running) { + struct rcar_dmac_desc *desc; + + desc = list_first_entry(&rchan->desc.active, + struct rcar_dmac_desc, node); + rchan->desc.running = desc; + + rcar_dmac_chan_start_xfer(rchan); + } + +done: + spin_unlock_irqrestore(&rchan->lock, flags); +} + +static void rcar_dmac_device_synchronize(struct dma_chan *chan) +{ + struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); + + synchronize_irq(rchan->irq); +} + +/* ----------------------------------------------------------------------------- + * IRQ handling + */ + +static irqreturn_t rcar_dmac_isr_desc_stage_end(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc = chan->desc.running; + unsigned int stage; + + if (WARN_ON(!desc || !desc->cyclic)) { + /* + * This should never happen, there should always be a running + * cyclic descriptor when a descriptor stage end interrupt is + * triggered. Warn and return. + */ + return IRQ_NONE; + } + + /* Program the interrupt pointer to the next stage. */ + stage = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & + RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; + rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(stage)); + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan) +{ + struct rcar_dmac_desc *desc = chan->desc.running; + irqreturn_t ret = IRQ_WAKE_THREAD; + + if (WARN_ON_ONCE(!desc)) { + /* + * This should never happen, there should always be a running + * descriptor when a transfer end interrupt is triggered. Warn + * and return. + */ + return IRQ_NONE; + } + + /* + * The transfer end interrupt isn't generated for each chunk when using + * descriptor mode. Only update the running chunk pointer in + * non-descriptor mode. + */ + if (!desc->hwdescs.use) { + /* + * If we haven't completed the last transfer chunk simply move + * to the next one. Only wake the IRQ thread if the transfer is + * cyclic. + */ + if (!list_is_last(&desc->running->node, &desc->chunks)) { + desc->running = list_next_entry(desc->running, node); + if (!desc->cyclic) + ret = IRQ_HANDLED; + goto done; + } + + /* + * We've completed the last transfer chunk. If the transfer is + * cyclic, move back to the first one. + */ + if (desc->cyclic) { + desc->running = + list_first_entry(&desc->chunks, + struct rcar_dmac_xfer_chunk, + node); + goto done; + } + } + + /* The descriptor is complete, move it to the done list. */ + list_move_tail(&desc->node, &chan->desc.done); + + /* Queue the next descriptor, if any. */ + if (!list_empty(&chan->desc.active)) + chan->desc.running = list_first_entry(&chan->desc.active, + struct rcar_dmac_desc, + node); + else + chan->desc.running = NULL; + +done: + if (chan->desc.running) + rcar_dmac_chan_start_xfer(chan); + + return ret; +} + +static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev) +{ + u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE; + struct rcar_dmac_chan *chan = dev; + irqreturn_t ret = IRQ_NONE; + bool reinit = false; + u32 chcr; + + spin_lock(&chan->lock); + + chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); + if (chcr & RCAR_DMACHCR_CAE) { + struct rcar_dmac *dmac = to_rcar_dmac(chan->chan.device); + + /* + * We don't need to call rcar_dmac_chan_halt() + * because channel is already stopped in error case. + * We need to clear register and check DE bit as recovery. + */ + rcar_dmac_chan_clear(dmac, chan); + rcar_dmac_chcr_de_barrier(chan); + reinit = true; + goto spin_lock_end; + } + + if (chcr & RCAR_DMACHCR_TE) + mask |= RCAR_DMACHCR_DE; + rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask); + if (mask & RCAR_DMACHCR_DE) + rcar_dmac_chcr_de_barrier(chan); + + if (chcr & RCAR_DMACHCR_DSE) + ret |= rcar_dmac_isr_desc_stage_end(chan); + + if (chcr & RCAR_DMACHCR_TE) + ret |= rcar_dmac_isr_transfer_end(chan); + +spin_lock_end: + spin_unlock(&chan->lock); + + if (reinit) { + dev_err(chan->chan.device->dev, "Channel Address Error\n"); + + rcar_dmac_chan_reinit(chan); + ret = IRQ_HANDLED; + } + + return ret; +} + +static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev) +{ + struct rcar_dmac_chan *chan = dev; + struct rcar_dmac_desc *desc; + struct dmaengine_desc_callback cb; + + spin_lock_irq(&chan->lock); + + /* For cyclic transfers notify the user after every chunk. */ + if (chan->desc.running && chan->desc.running->cyclic) { + desc = chan->desc.running; + dmaengine_desc_get_callback(&desc->async_tx, &cb); + + if (dmaengine_desc_callback_valid(&cb)) { + spin_unlock_irq(&chan->lock); + dmaengine_desc_callback_invoke(&cb, NULL); + spin_lock_irq(&chan->lock); + } + } + + /* + * Call the callback function for all descriptors on the done list and + * move them to the ack wait list. + */ + while (!list_empty(&chan->desc.done)) { + desc = list_first_entry(&chan->desc.done, struct rcar_dmac_desc, + node); + dma_cookie_complete(&desc->async_tx); + list_del(&desc->node); + + dmaengine_desc_get_callback(&desc->async_tx, &cb); + if (dmaengine_desc_callback_valid(&cb)) { + spin_unlock_irq(&chan->lock); + /* + * We own the only reference to this descriptor, we can + * safely dereference it without holding the channel + * lock. + */ + dmaengine_desc_callback_invoke(&cb, NULL); + spin_lock_irq(&chan->lock); + } + + list_add_tail(&desc->node, &chan->desc.wait); + } + + spin_unlock_irq(&chan->lock); + + /* Recycle all acked descriptors. */ + rcar_dmac_desc_recycle_acked(chan); + + return IRQ_HANDLED; +} + +/* ----------------------------------------------------------------------------- + * OF xlate and channel filter + */ + +static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg) +{ + struct rcar_dmac *dmac = to_rcar_dmac(chan->device); + struct of_phandle_args *dma_spec = arg; + + /* + * FIXME: Using a filter on OF platforms is a nonsense. The OF xlate + * function knows from which device it wants to allocate a channel from, + * and would be perfectly capable of selecting the channel it wants. + * Forcing it to call dma_request_channel() and iterate through all + * channels from all controllers is just pointless. + */ + if (chan->device->device_config != rcar_dmac_device_config) + return false; + + return !test_and_set_bit(dma_spec->args[0], dmac->modules); +} + +static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct rcar_dmac_chan *rchan; + struct dma_chan *chan; + dma_cap_mask_t mask; + + if (dma_spec->args_count != 1) + return NULL; + + /* Only slave DMA channels can be allocated via DT */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = __dma_request_channel(&mask, rcar_dmac_chan_filter, dma_spec, + ofdma->of_node); + if (!chan) + return NULL; + + rchan = to_rcar_dmac_chan(chan); + rchan->mid_rid = dma_spec->args[0]; + + return chan; +} + +/* ----------------------------------------------------------------------------- + * Power management + */ + +#ifdef CONFIG_PM +static int rcar_dmac_runtime_suspend(struct device *dev) +{ + return 0; +} + +static int rcar_dmac_runtime_resume(struct device *dev) +{ + struct rcar_dmac *dmac = dev_get_drvdata(dev); + + return rcar_dmac_init(dmac); +} +#endif + +static const struct dev_pm_ops rcar_dmac_pm = { + /* + * TODO for system sleep/resume: + * - Wait for the current transfer to complete and stop the device, + * - Resume transfers, if any. + */ + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume, + NULL) +}; + +/* ----------------------------------------------------------------------------- + * Probe and remove + */ + +static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, + struct rcar_dmac_chan *rchan) +{ + struct platform_device *pdev = to_platform_device(dmac->dev); + struct dma_chan *chan = &rchan->chan; + char pdev_irqname[5]; + char *irqname; + int ret; + + rchan->mid_rid = -EINVAL; + + spin_lock_init(&rchan->lock); + + INIT_LIST_HEAD(&rchan->desc.free); + INIT_LIST_HEAD(&rchan->desc.pending); + INIT_LIST_HEAD(&rchan->desc.active); + INIT_LIST_HEAD(&rchan->desc.done); + INIT_LIST_HEAD(&rchan->desc.wait); + + /* Request the channel interrupt. */ + sprintf(pdev_irqname, "ch%u", rchan->index); + rchan->irq = platform_get_irq_byname(pdev, pdev_irqname); + if (rchan->irq < 0) + return -ENODEV; + + irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", + dev_name(dmac->dev), rchan->index); + if (!irqname) + return -ENOMEM; + + /* + * Initialize the DMA engine channel and add it to the DMA engine + * channels list. + */ + chan->device = &dmac->engine; + dma_cookie_init(chan); + + list_add_tail(&chan->device_node, &dmac->engine.channels); + + ret = devm_request_threaded_irq(dmac->dev, rchan->irq, + rcar_dmac_isr_channel, + rcar_dmac_isr_channel_thread, 0, + irqname, rchan); + if (ret) { + dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", + rchan->irq, ret); + return ret; + } + + return 0; +} + +#define RCAR_DMAC_MAX_CHANNELS 32 + +static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac) +{ + struct device_node *np = dev->of_node; + int ret; + + ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); + if (ret < 0) { + dev_err(dev, "unable to read dma-channels property\n"); + return ret; + } + + /* The hardware and driver don't support more than 32 bits in CHCLR */ + if (dmac->n_channels <= 0 || + dmac->n_channels >= RCAR_DMAC_MAX_CHANNELS) { + dev_err(dev, "invalid number of channels %u\n", + dmac->n_channels); + return -EINVAL; + } + + /* + * If the driver is unable to read dma-channel-mask property, + * the driver assumes that it can use all channels. + */ + dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0); + of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask); + + /* If the property has out-of-channel mask, this driver clears it */ + dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0); + + return 0; +} + +static int rcar_dmac_probe(struct platform_device *pdev) +{ + const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | + DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES | + DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES | + DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES; + const struct rcar_dmac_of_data *data; + struct rcar_dmac_chan *chan; + struct dma_device *engine; + void __iomem *chan_base; + struct rcar_dmac *dmac; + unsigned int i; + int ret; + + data = of_device_get_match_data(&pdev->dev); + if (!data) + return -EINVAL; + + dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); + if (!dmac) + return -ENOMEM; + + dmac->dev = &pdev->dev; + platform_set_drvdata(pdev, dmac); + ret = dma_set_max_seg_size(dmac->dev, RCAR_DMATCR_MASK); + if (ret) + return ret; + + ret = dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40)); + if (ret) + return ret; + + ret = rcar_dmac_parse_of(&pdev->dev, dmac); + if (ret < 0) + return ret; + + /* + * A still unconfirmed hardware bug prevents the IPMMU microTLB 0 to be + * flushed correctly, resulting in memory corruption. DMAC 0 channel 0 + * is connected to microTLB 0 on currently supported platforms, so we + * can't use it with the IPMMU. As the IOMMU API operates at the device + * level we can't disable it selectively, so ignore channel 0 for now if + * the device is part of an IOMMU group. + */ + if (device_iommu_mapped(&pdev->dev)) + dmac->channels_mask &= ~BIT(0); + + dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, + sizeof(*dmac->channels), GFP_KERNEL); + if (!dmac->channels) + return -ENOMEM; + + /* Request resources. */ + dmac->dmac_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(dmac->dmac_base)) + return PTR_ERR(dmac->dmac_base); + + if (!data->chan_offset_base) { + dmac->chan_base = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(dmac->chan_base)) + return PTR_ERR(dmac->chan_base); + + chan_base = dmac->chan_base; + } else { + chan_base = dmac->dmac_base + data->chan_offset_base; + } + + for_each_rcar_dmac_chan(i, dmac, chan) { + chan->index = i; + chan->iomem = chan_base + i * data->chan_offset_stride; + } + + /* Enable runtime PM and initialize the device. */ + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) { + dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); + goto err_pm_disable; + } + + ret = rcar_dmac_init(dmac); + pm_runtime_put(&pdev->dev); + + if (ret) { + dev_err(&pdev->dev, "failed to reset device\n"); + goto err_pm_disable; + } + + /* Initialize engine */ + engine = &dmac->engine; + + dma_cap_set(DMA_MEMCPY, engine->cap_mask); + dma_cap_set(DMA_SLAVE, engine->cap_mask); + + engine->dev = &pdev->dev; + engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE); + + engine->src_addr_widths = widths; + engine->dst_addr_widths = widths; + engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); + engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + + engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources; + engine->device_free_chan_resources = rcar_dmac_free_chan_resources; + engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy; + engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg; + engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic; + engine->device_config = rcar_dmac_device_config; + engine->device_pause = rcar_dmac_chan_pause; + engine->device_terminate_all = rcar_dmac_chan_terminate_all; + engine->device_tx_status = rcar_dmac_tx_status; + engine->device_issue_pending = rcar_dmac_issue_pending; + engine->device_synchronize = rcar_dmac_device_synchronize; + + INIT_LIST_HEAD(&engine->channels); + + for_each_rcar_dmac_chan(i, dmac, chan) { + ret = rcar_dmac_chan_probe(dmac, chan); + if (ret < 0) + goto err_pm_disable; + } + + /* Register the DMAC as a DMA provider for DT. */ + ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate, + NULL); + if (ret < 0) + goto err_pm_disable; + + /* + * Register the DMA engine device. + * + * Default transfer size of 32 bytes requires 32-byte alignment. + */ + ret = dma_async_device_register(engine); + if (ret < 0) + goto err_dma_free; + + return 0; + +err_dma_free: + of_dma_controller_free(pdev->dev.of_node); +err_pm_disable: + pm_runtime_disable(&pdev->dev); + return ret; +} + +static int rcar_dmac_remove(struct platform_device *pdev) +{ + struct rcar_dmac *dmac = platform_get_drvdata(pdev); + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&dmac->engine); + + pm_runtime_disable(&pdev->dev); + + return 0; +} + +static void rcar_dmac_shutdown(struct platform_device *pdev) +{ + struct rcar_dmac *dmac = platform_get_drvdata(pdev); + + rcar_dmac_stop_all_chan(dmac); +} + +static const struct rcar_dmac_of_data rcar_dmac_data = { + .chan_offset_base = 0x8000, + .chan_offset_stride = 0x80, +}; + +static const struct rcar_dmac_of_data rcar_gen4_dmac_data = { + .chan_offset_base = 0x0, + .chan_offset_stride = 0x1000, +}; + +static const struct of_device_id rcar_dmac_of_ids[] = { + { + .compatible = "renesas,rcar-dmac", + .data = &rcar_dmac_data, + }, { + .compatible = "renesas,rcar-gen4-dmac", + .data = &rcar_gen4_dmac_data, + }, { + .compatible = "renesas,dmac-r8a779a0", + .data = &rcar_gen4_dmac_data, + }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids); + +static struct platform_driver rcar_dmac_driver = { + .driver = { + .pm = &rcar_dmac_pm, + .name = "rcar-dmac", + .of_match_table = rcar_dmac_of_ids, + }, + .probe = rcar_dmac_probe, + .remove = rcar_dmac_remove, + .shutdown = rcar_dmac_shutdown, +}; + +module_platform_driver(rcar_dmac_driver); + +MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver"); +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c new file mode 100644 index 000000000..2967141f4 --- /dev/null +++ b/drivers/dma/sh/rz-dmac.c @@ -0,0 +1,1003 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L DMA Controller Driver + * + * Based on imx-dma.c + * + * Copyright (C) 2021 Renesas Electronics Corp. + * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de> + * Copyright 2012 Javier Martin, Vista Silicon <javier.martin@vista-silicon.com> + */ + +#include <linux/bitfield.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "../dmaengine.h" +#include "../virt-dma.h" + +enum rz_dmac_prep_type { + RZ_DMAC_DESC_MEMCPY, + RZ_DMAC_DESC_SLAVE_SG, +}; + +struct rz_lmdesc { + u32 header; + u32 sa; + u32 da; + u32 tb; + u32 chcfg; + u32 chitvl; + u32 chext; + u32 nxla; +}; + +struct rz_dmac_desc { + struct virt_dma_desc vd; + dma_addr_t src; + dma_addr_t dest; + size_t len; + struct list_head node; + enum dma_transfer_direction direction; + enum rz_dmac_prep_type type; + /* For slave sg */ + struct scatterlist *sg; + unsigned int sgcount; +}; + +#define to_rz_dmac_desc(d) container_of(d, struct rz_dmac_desc, vd) + +struct rz_dmac_chan { + struct virt_dma_chan vc; + void __iomem *ch_base; + void __iomem *ch_cmn_base; + unsigned int index; + int irq; + struct rz_dmac_desc *desc; + int descs_allocated; + + enum dma_slave_buswidth src_word_size; + enum dma_slave_buswidth dst_word_size; + dma_addr_t src_per_address; + dma_addr_t dst_per_address; + + u32 chcfg; + u32 chctrl; + int mid_rid; + + struct list_head ld_free; + struct list_head ld_queue; + struct list_head ld_active; + + struct { + struct rz_lmdesc *base; + struct rz_lmdesc *head; + struct rz_lmdesc *tail; + dma_addr_t base_dma; + } lmdesc; +}; + +#define to_rz_dmac_chan(c) container_of(c, struct rz_dmac_chan, vc.chan) + +struct rz_dmac { + struct dma_device engine; + struct device *dev; + void __iomem *base; + void __iomem *ext_base; + + unsigned int n_channels; + struct rz_dmac_chan *channels; + + DECLARE_BITMAP(modules, 1024); +}; + +#define to_rz_dmac(d) container_of(d, struct rz_dmac, engine) + +/* + * ----------------------------------------------------------------------------- + * Registers + */ + +#define CHSTAT 0x0024 +#define CHCTRL 0x0028 +#define CHCFG 0x002c +#define NXLA 0x0038 + +#define DCTRL 0x0000 + +#define EACH_CHANNEL_OFFSET 0x0040 +#define CHANNEL_0_7_OFFSET 0x0000 +#define CHANNEL_0_7_COMMON_BASE 0x0300 +#define CHANNEL_8_15_OFFSET 0x0400 +#define CHANNEL_8_15_COMMON_BASE 0x0700 + +#define CHSTAT_ER BIT(4) +#define CHSTAT_EN BIT(0) + +#define CHCTRL_CLRINTMSK BIT(17) +#define CHCTRL_CLRSUS BIT(9) +#define CHCTRL_CLRTC BIT(6) +#define CHCTRL_CLREND BIT(5) +#define CHCTRL_CLRRQ BIT(4) +#define CHCTRL_SWRST BIT(3) +#define CHCTRL_STG BIT(2) +#define CHCTRL_CLREN BIT(1) +#define CHCTRL_SETEN BIT(0) +#define CHCTRL_DEFAULT (CHCTRL_CLRINTMSK | CHCTRL_CLRSUS | \ + CHCTRL_CLRTC | CHCTRL_CLREND | \ + CHCTRL_CLRRQ | CHCTRL_SWRST | \ + CHCTRL_CLREN) + +#define CHCFG_DMS BIT(31) +#define CHCFG_DEM BIT(24) +#define CHCFG_DAD BIT(21) +#define CHCFG_SAD BIT(20) +#define CHCFG_REQD BIT(3) +#define CHCFG_SEL(bits) ((bits) & 0x07) +#define CHCFG_MEM_COPY (0x80400008) +#define CHCFG_FILL_DDS_MASK GENMASK(19, 16) +#define CHCFG_FILL_SDS_MASK GENMASK(15, 12) +#define CHCFG_FILL_TM(a) (((a) & BIT(5)) << 22) +#define CHCFG_FILL_AM(a) (((a) & GENMASK(4, 2)) << 6) +#define CHCFG_FILL_LVL(a) (((a) & BIT(1)) << 5) +#define CHCFG_FILL_HIEN(a) (((a) & BIT(0)) << 5) + +#define MID_RID_MASK GENMASK(9, 0) +#define CHCFG_MASK GENMASK(15, 10) +#define CHCFG_DS_INVALID 0xFF +#define DCTRL_LVINT BIT(1) +#define DCTRL_PR BIT(0) +#define DCTRL_DEFAULT (DCTRL_LVINT | DCTRL_PR) + +/* LINK MODE DESCRIPTOR */ +#define HEADER_LV BIT(0) + +#define RZ_DMAC_MAX_CHAN_DESCRIPTORS 16 +#define RZ_DMAC_MAX_CHANNELS 16 +#define DMAC_NR_LMDESC 64 + +/* + * ----------------------------------------------------------------------------- + * Device access + */ + +static void rz_dmac_writel(struct rz_dmac *dmac, unsigned int val, + unsigned int offset) +{ + writel(val, dmac->base + offset); +} + +static void rz_dmac_ext_writel(struct rz_dmac *dmac, unsigned int val, + unsigned int offset) +{ + writel(val, dmac->ext_base + offset); +} + +static u32 rz_dmac_ext_readl(struct rz_dmac *dmac, unsigned int offset) +{ + return readl(dmac->ext_base + offset); +} + +static void rz_dmac_ch_writel(struct rz_dmac_chan *channel, unsigned int val, + unsigned int offset, int which) +{ + if (which) + writel(val, channel->ch_base + offset); + else + writel(val, channel->ch_cmn_base + offset); +} + +static u32 rz_dmac_ch_readl(struct rz_dmac_chan *channel, + unsigned int offset, int which) +{ + if (which) + return readl(channel->ch_base + offset); + else + return readl(channel->ch_cmn_base + offset); +} + +/* + * ----------------------------------------------------------------------------- + * Initialization + */ + +static void rz_lmdesc_setup(struct rz_dmac_chan *channel, + struct rz_lmdesc *lmdesc) +{ + u32 nxla; + + channel->lmdesc.base = lmdesc; + channel->lmdesc.head = lmdesc; + channel->lmdesc.tail = lmdesc; + nxla = channel->lmdesc.base_dma; + while (lmdesc < (channel->lmdesc.base + (DMAC_NR_LMDESC - 1))) { + lmdesc->header = 0; + nxla += sizeof(*lmdesc); + lmdesc->nxla = nxla; + lmdesc++; + } + + lmdesc->header = 0; + lmdesc->nxla = channel->lmdesc.base_dma; +} + +/* + * ----------------------------------------------------------------------------- + * Descriptors preparation + */ + +static void rz_dmac_lmdesc_recycle(struct rz_dmac_chan *channel) +{ + struct rz_lmdesc *lmdesc = channel->lmdesc.head; + + while (!(lmdesc->header & HEADER_LV)) { + lmdesc->header = 0; + lmdesc++; + if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC)) + lmdesc = channel->lmdesc.base; + } + channel->lmdesc.head = lmdesc; +} + +static void rz_dmac_enable_hw(struct rz_dmac_chan *channel) +{ + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + unsigned long flags; + u32 nxla; + u32 chctrl; + u32 chstat; + + dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index); + + local_irq_save(flags); + + rz_dmac_lmdesc_recycle(channel); + + nxla = channel->lmdesc.base_dma + + (sizeof(struct rz_lmdesc) * (channel->lmdesc.head - + channel->lmdesc.base)); + + chstat = rz_dmac_ch_readl(channel, CHSTAT, 1); + if (!(chstat & CHSTAT_EN)) { + chctrl = (channel->chctrl | CHCTRL_SETEN); + rz_dmac_ch_writel(channel, nxla, NXLA, 1); + rz_dmac_ch_writel(channel, channel->chcfg, CHCFG, 1); + rz_dmac_ch_writel(channel, CHCTRL_SWRST, CHCTRL, 1); + rz_dmac_ch_writel(channel, chctrl, CHCTRL, 1); + } + + local_irq_restore(flags); +} + +static void rz_dmac_disable_hw(struct rz_dmac_chan *channel) +{ + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + unsigned long flags; + + dev_dbg(dmac->dev, "%s channel %d\n", __func__, channel->index); + + local_irq_save(flags); + rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1); + local_irq_restore(flags); +} + +static void rz_dmac_set_dmars_register(struct rz_dmac *dmac, int nr, u32 dmars) +{ + u32 dmars_offset = (nr / 2) * 4; + u32 shift = (nr % 2) * 16; + u32 dmars32; + + dmars32 = rz_dmac_ext_readl(dmac, dmars_offset); + dmars32 &= ~(0xffff << shift); + dmars32 |= dmars << shift; + + rz_dmac_ext_writel(dmac, dmars32, dmars_offset); +} + +static void rz_dmac_prepare_desc_for_memcpy(struct rz_dmac_chan *channel) +{ + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct rz_lmdesc *lmdesc = channel->lmdesc.tail; + struct rz_dmac_desc *d = channel->desc; + u32 chcfg = CHCFG_MEM_COPY; + + /* prepare descriptor */ + lmdesc->sa = d->src; + lmdesc->da = d->dest; + lmdesc->tb = d->len; + lmdesc->chcfg = chcfg; + lmdesc->chitvl = 0; + lmdesc->chext = 0; + lmdesc->header = HEADER_LV; + + rz_dmac_set_dmars_register(dmac, channel->index, 0); + + channel->chcfg = chcfg; + channel->chctrl = CHCTRL_STG | CHCTRL_SETEN; +} + +static void rz_dmac_prepare_descs_for_slave_sg(struct rz_dmac_chan *channel) +{ + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct rz_dmac_desc *d = channel->desc; + struct scatterlist *sg, *sgl = d->sg; + struct rz_lmdesc *lmdesc; + unsigned int i, sg_len = d->sgcount; + + channel->chcfg |= CHCFG_SEL(channel->index) | CHCFG_DEM | CHCFG_DMS; + + if (d->direction == DMA_DEV_TO_MEM) { + channel->chcfg |= CHCFG_SAD; + channel->chcfg &= ~CHCFG_REQD; + } else { + channel->chcfg |= CHCFG_DAD | CHCFG_REQD; + } + + lmdesc = channel->lmdesc.tail; + + for (i = 0, sg = sgl; i < sg_len; i++, sg = sg_next(sg)) { + if (d->direction == DMA_DEV_TO_MEM) { + lmdesc->sa = channel->src_per_address; + lmdesc->da = sg_dma_address(sg); + } else { + lmdesc->sa = sg_dma_address(sg); + lmdesc->da = channel->dst_per_address; + } + + lmdesc->tb = sg_dma_len(sg); + lmdesc->chitvl = 0; + lmdesc->chext = 0; + if (i == (sg_len - 1)) { + lmdesc->chcfg = (channel->chcfg & ~CHCFG_DEM); + lmdesc->header = HEADER_LV; + } else { + lmdesc->chcfg = channel->chcfg; + lmdesc->header = HEADER_LV; + } + if (++lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC)) + lmdesc = channel->lmdesc.base; + } + + channel->lmdesc.tail = lmdesc; + + rz_dmac_set_dmars_register(dmac, channel->index, channel->mid_rid); + channel->chctrl = CHCTRL_SETEN; +} + +static int rz_dmac_xfer_desc(struct rz_dmac_chan *chan) +{ + struct rz_dmac_desc *d = chan->desc; + struct virt_dma_desc *vd; + + vd = vchan_next_desc(&chan->vc); + if (!vd) + return 0; + + list_del(&vd->node); + + switch (d->type) { + case RZ_DMAC_DESC_MEMCPY: + rz_dmac_prepare_desc_for_memcpy(chan); + break; + + case RZ_DMAC_DESC_SLAVE_SG: + rz_dmac_prepare_descs_for_slave_sg(chan); + break; + + default: + return -EINVAL; + } + + rz_dmac_enable_hw(chan); + + return 0; +} + +/* + * ----------------------------------------------------------------------------- + * DMA engine operations + */ + +static int rz_dmac_alloc_chan_resources(struct dma_chan *chan) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + + while (channel->descs_allocated < RZ_DMAC_MAX_CHAN_DESCRIPTORS) { + struct rz_dmac_desc *desc; + + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + break; + + list_add_tail(&desc->node, &channel->ld_free); + channel->descs_allocated++; + } + + if (!channel->descs_allocated) + return -ENOMEM; + + return channel->descs_allocated; +} + +static void rz_dmac_free_chan_resources(struct dma_chan *chan) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct rz_lmdesc *lmdesc = channel->lmdesc.base; + struct rz_dmac_desc *desc, *_desc; + unsigned long flags; + unsigned int i; + + spin_lock_irqsave(&channel->vc.lock, flags); + + for (i = 0; i < DMAC_NR_LMDESC; i++) + lmdesc[i].header = 0; + + rz_dmac_disable_hw(channel); + list_splice_tail_init(&channel->ld_active, &channel->ld_free); + list_splice_tail_init(&channel->ld_queue, &channel->ld_free); + + if (channel->mid_rid >= 0) { + clear_bit(channel->mid_rid, dmac->modules); + channel->mid_rid = -EINVAL; + } + + spin_unlock_irqrestore(&channel->vc.lock, flags); + + list_for_each_entry_safe(desc, _desc, &channel->ld_free, node) { + kfree(desc); + channel->descs_allocated--; + } + + INIT_LIST_HEAD(&channel->ld_free); + vchan_free_chan_resources(&channel->vc); +} + +static struct dma_async_tx_descriptor * +rz_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct rz_dmac_desc *desc; + + dev_dbg(dmac->dev, "%s channel: %d src=0x%pad dst=0x%pad len=%zu\n", + __func__, channel->index, &src, &dest, len); + + if (list_empty(&channel->ld_free)) + return NULL; + + desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node); + + desc->type = RZ_DMAC_DESC_MEMCPY; + desc->src = src; + desc->dest = dest; + desc->len = len; + desc->direction = DMA_MEM_TO_MEM; + + list_move_tail(channel->ld_free.next, &channel->ld_queue); + return vchan_tx_prep(&channel->vc, &desc->vd, flags); +} + +static struct dma_async_tx_descriptor * +rz_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, + enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac_desc *desc; + struct scatterlist *sg; + int dma_length = 0; + int i = 0; + + if (list_empty(&channel->ld_free)) + return NULL; + + desc = list_first_entry(&channel->ld_free, struct rz_dmac_desc, node); + + for_each_sg(sgl, sg, sg_len, i) { + dma_length += sg_dma_len(sg); + } + + desc->type = RZ_DMAC_DESC_SLAVE_SG; + desc->sg = sgl; + desc->sgcount = sg_len; + desc->len = dma_length; + desc->direction = direction; + + if (direction == DMA_DEV_TO_MEM) + desc->src = channel->src_per_address; + else + desc->dest = channel->dst_per_address; + + list_move_tail(channel->ld_free.next, &channel->ld_queue); + return vchan_tx_prep(&channel->vc, &desc->vd, flags); +} + +static int rz_dmac_terminate_all(struct dma_chan *chan) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + unsigned long flags; + LIST_HEAD(head); + + rz_dmac_disable_hw(channel); + spin_lock_irqsave(&channel->vc.lock, flags); + list_splice_tail_init(&channel->ld_active, &channel->ld_free); + list_splice_tail_init(&channel->ld_queue, &channel->ld_free); + spin_unlock_irqrestore(&channel->vc.lock, flags); + vchan_get_all_descriptors(&channel->vc, &head); + vchan_dma_desc_free_list(&channel->vc, &head); + + return 0; +} + +static void rz_dmac_issue_pending(struct dma_chan *chan) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct rz_dmac_desc *desc; + unsigned long flags; + + spin_lock_irqsave(&channel->vc.lock, flags); + + if (!list_empty(&channel->ld_queue)) { + desc = list_first_entry(&channel->ld_queue, + struct rz_dmac_desc, node); + channel->desc = desc; + if (vchan_issue_pending(&channel->vc)) { + if (rz_dmac_xfer_desc(channel) < 0) + dev_warn(dmac->dev, "ch: %d couldn't issue DMA xfer\n", + channel->index); + else + list_move_tail(channel->ld_queue.next, + &channel->ld_active); + } + } + + spin_unlock_irqrestore(&channel->vc.lock, flags); +} + +static u8 rz_dmac_ds_to_val_mapping(enum dma_slave_buswidth ds) +{ + u8 i; + static const enum dma_slave_buswidth ds_lut[] = { + DMA_SLAVE_BUSWIDTH_1_BYTE, + DMA_SLAVE_BUSWIDTH_2_BYTES, + DMA_SLAVE_BUSWIDTH_4_BYTES, + DMA_SLAVE_BUSWIDTH_8_BYTES, + DMA_SLAVE_BUSWIDTH_16_BYTES, + DMA_SLAVE_BUSWIDTH_32_BYTES, + DMA_SLAVE_BUSWIDTH_64_BYTES, + DMA_SLAVE_BUSWIDTH_128_BYTES, + }; + + for (i = 0; i < ARRAY_SIZE(ds_lut); i++) { + if (ds_lut[i] == ds) + return i; + } + + return CHCFG_DS_INVALID; +} + +static int rz_dmac_config(struct dma_chan *chan, + struct dma_slave_config *config) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + u32 val; + + channel->src_per_address = config->src_addr; + channel->src_word_size = config->src_addr_width; + channel->dst_per_address = config->dst_addr; + channel->dst_word_size = config->dst_addr_width; + + val = rz_dmac_ds_to_val_mapping(config->dst_addr_width); + if (val == CHCFG_DS_INVALID) + return -EINVAL; + + channel->chcfg &= ~CHCFG_FILL_DDS_MASK; + channel->chcfg |= FIELD_PREP(CHCFG_FILL_DDS_MASK, val); + + val = rz_dmac_ds_to_val_mapping(config->src_addr_width); + if (val == CHCFG_DS_INVALID) + return -EINVAL; + + channel->chcfg &= ~CHCFG_FILL_SDS_MASK; + channel->chcfg |= FIELD_PREP(CHCFG_FILL_SDS_MASK, val); + + return 0; +} + +static void rz_dmac_virt_desc_free(struct virt_dma_desc *vd) +{ + /* + * Place holder + * Descriptor allocation is done during alloc_chan_resources and + * get freed during free_chan_resources. + * list is used to manage the descriptors and avoid any memory + * allocation/free during DMA read/write. + */ +} + +static void rz_dmac_device_synchronize(struct dma_chan *chan) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac *dmac = to_rz_dmac(chan->device); + u32 chstat; + int ret; + + ret = read_poll_timeout(rz_dmac_ch_readl, chstat, !(chstat & CHSTAT_EN), + 100, 100000, false, channel, CHSTAT, 1); + if (ret < 0) + dev_warn(dmac->dev, "DMA Timeout"); + + rz_dmac_set_dmars_register(dmac, channel->index, 0); +} + +/* + * ----------------------------------------------------------------------------- + * IRQ handling + */ + +static void rz_dmac_irq_handle_channel(struct rz_dmac_chan *channel) +{ + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + u32 chstat, chctrl; + + chstat = rz_dmac_ch_readl(channel, CHSTAT, 1); + if (chstat & CHSTAT_ER) { + dev_err(dmac->dev, "DMAC err CHSTAT_%d = %08X\n", + channel->index, chstat); + rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1); + goto done; + } + + chctrl = rz_dmac_ch_readl(channel, CHCTRL, 1); + rz_dmac_ch_writel(channel, chctrl | CHCTRL_CLREND, CHCTRL, 1); +done: + return; +} + +static irqreturn_t rz_dmac_irq_handler(int irq, void *dev_id) +{ + struct rz_dmac_chan *channel = dev_id; + + if (channel) { + rz_dmac_irq_handle_channel(channel); + return IRQ_WAKE_THREAD; + } + /* handle DMAERR irq */ + return IRQ_HANDLED; +} + +static irqreturn_t rz_dmac_irq_handler_thread(int irq, void *dev_id) +{ + struct rz_dmac_chan *channel = dev_id; + struct rz_dmac_desc *desc = NULL; + unsigned long flags; + + spin_lock_irqsave(&channel->vc.lock, flags); + + if (list_empty(&channel->ld_active)) { + /* Someone might have called terminate all */ + goto out; + } + + desc = list_first_entry(&channel->ld_active, struct rz_dmac_desc, node); + vchan_cookie_complete(&desc->vd); + list_move_tail(channel->ld_active.next, &channel->ld_free); + if (!list_empty(&channel->ld_queue)) { + desc = list_first_entry(&channel->ld_queue, struct rz_dmac_desc, + node); + channel->desc = desc; + if (rz_dmac_xfer_desc(channel) == 0) + list_move_tail(channel->ld_queue.next, &channel->ld_active); + } +out: + spin_unlock_irqrestore(&channel->vc.lock, flags); + + return IRQ_HANDLED; +} + +/* + * ----------------------------------------------------------------------------- + * OF xlate and channel filter + */ + +static bool rz_dmac_chan_filter(struct dma_chan *chan, void *arg) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + struct rz_dmac *dmac = to_rz_dmac(chan->device); + struct of_phandle_args *dma_spec = arg; + u32 ch_cfg; + + channel->mid_rid = dma_spec->args[0] & MID_RID_MASK; + ch_cfg = (dma_spec->args[0] & CHCFG_MASK) >> 10; + channel->chcfg = CHCFG_FILL_TM(ch_cfg) | CHCFG_FILL_AM(ch_cfg) | + CHCFG_FILL_LVL(ch_cfg) | CHCFG_FILL_HIEN(ch_cfg); + + return !test_and_set_bit(channel->mid_rid, dmac->modules); +} + +static struct dma_chan *rz_dmac_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + dma_cap_mask_t mask; + + if (dma_spec->args_count != 1) + return NULL; + + /* Only slave DMA channels can be allocated via DT */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + return dma_request_channel(mask, rz_dmac_chan_filter, dma_spec); +} + +/* + * ----------------------------------------------------------------------------- + * Probe and remove + */ + +static int rz_dmac_chan_probe(struct rz_dmac *dmac, + struct rz_dmac_chan *channel, + unsigned int index) +{ + struct platform_device *pdev = to_platform_device(dmac->dev); + struct rz_lmdesc *lmdesc; + char pdev_irqname[5]; + char *irqname; + int ret; + + channel->index = index; + channel->mid_rid = -EINVAL; + + /* Request the channel interrupt. */ + sprintf(pdev_irqname, "ch%u", index); + channel->irq = platform_get_irq_byname(pdev, pdev_irqname); + if (channel->irq < 0) + return channel->irq; + + irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", + dev_name(dmac->dev), index); + if (!irqname) + return -ENOMEM; + + ret = devm_request_threaded_irq(dmac->dev, channel->irq, + rz_dmac_irq_handler, + rz_dmac_irq_handler_thread, 0, + irqname, channel); + if (ret) { + dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", + channel->irq, ret); + return ret; + } + + /* Set io base address for each channel */ + if (index < 8) { + channel->ch_base = dmac->base + CHANNEL_0_7_OFFSET + + EACH_CHANNEL_OFFSET * index; + channel->ch_cmn_base = dmac->base + CHANNEL_0_7_COMMON_BASE; + } else { + channel->ch_base = dmac->base + CHANNEL_8_15_OFFSET + + EACH_CHANNEL_OFFSET * (index - 8); + channel->ch_cmn_base = dmac->base + CHANNEL_8_15_COMMON_BASE; + } + + /* Allocate descriptors */ + lmdesc = dma_alloc_coherent(&pdev->dev, + sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC, + &channel->lmdesc.base_dma, GFP_KERNEL); + if (!lmdesc) { + dev_err(&pdev->dev, "Can't allocate memory (lmdesc)\n"); + return -ENOMEM; + } + rz_lmdesc_setup(channel, lmdesc); + + /* Initialize register for each channel */ + rz_dmac_ch_writel(channel, CHCTRL_DEFAULT, CHCTRL, 1); + + channel->vc.desc_free = rz_dmac_virt_desc_free; + vchan_init(&channel->vc, &dmac->engine); + INIT_LIST_HEAD(&channel->ld_queue); + INIT_LIST_HEAD(&channel->ld_free); + INIT_LIST_HEAD(&channel->ld_active); + + return 0; +} + +static int rz_dmac_parse_of(struct device *dev, struct rz_dmac *dmac) +{ + struct device_node *np = dev->of_node; + int ret; + + ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); + if (ret < 0) { + dev_err(dev, "unable to read dma-channels property\n"); + return ret; + } + + if (!dmac->n_channels || dmac->n_channels > RZ_DMAC_MAX_CHANNELS) { + dev_err(dev, "invalid number of channels %u\n", dmac->n_channels); + return -EINVAL; + } + + return 0; +} + +static int rz_dmac_probe(struct platform_device *pdev) +{ + const char *irqname = "error"; + struct dma_device *engine; + struct rz_dmac *dmac; + int channel_num; + unsigned int i; + int ret; + int irq; + + dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); + if (!dmac) + return -ENOMEM; + + dmac->dev = &pdev->dev; + platform_set_drvdata(pdev, dmac); + + ret = rz_dmac_parse_of(&pdev->dev, dmac); + if (ret < 0) + return ret; + + dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, + sizeof(*dmac->channels), GFP_KERNEL); + if (!dmac->channels) + return -ENOMEM; + + /* Request resources */ + dmac->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(dmac->base)) + return PTR_ERR(dmac->base); + + dmac->ext_base = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(dmac->ext_base)) + return PTR_ERR(dmac->ext_base); + + /* Register interrupt handler for error */ + irq = platform_get_irq_byname(pdev, irqname); + if (irq < 0) + return irq; + + ret = devm_request_irq(&pdev->dev, irq, rz_dmac_irq_handler, 0, + irqname, NULL); + if (ret) { + dev_err(&pdev->dev, "failed to request IRQ %u (%d)\n", + irq, ret); + return ret; + } + + /* Initialize the channels. */ + INIT_LIST_HEAD(&dmac->engine.channels); + + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) { + dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n"); + goto err_pm_disable; + } + + for (i = 0; i < dmac->n_channels; i++) { + ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i); + if (ret < 0) + goto err; + } + + /* Register the DMAC as a DMA provider for DT. */ + ret = of_dma_controller_register(pdev->dev.of_node, rz_dmac_of_xlate, + NULL); + if (ret < 0) + goto err; + + /* Register the DMA engine device. */ + engine = &dmac->engine; + dma_cap_set(DMA_SLAVE, engine->cap_mask); + dma_cap_set(DMA_MEMCPY, engine->cap_mask); + rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_0_7_COMMON_BASE + DCTRL); + rz_dmac_writel(dmac, DCTRL_DEFAULT, CHANNEL_8_15_COMMON_BASE + DCTRL); + + engine->dev = &pdev->dev; + + engine->device_alloc_chan_resources = rz_dmac_alloc_chan_resources; + engine->device_free_chan_resources = rz_dmac_free_chan_resources; + engine->device_tx_status = dma_cookie_status; + engine->device_prep_slave_sg = rz_dmac_prep_slave_sg; + engine->device_prep_dma_memcpy = rz_dmac_prep_dma_memcpy; + engine->device_config = rz_dmac_config; + engine->device_terminate_all = rz_dmac_terminate_all; + engine->device_issue_pending = rz_dmac_issue_pending; + engine->device_synchronize = rz_dmac_device_synchronize; + + engine->copy_align = DMAENGINE_ALIGN_1_BYTE; + dma_set_max_seg_size(engine->dev, U32_MAX); + + ret = dma_async_device_register(engine); + if (ret < 0) { + dev_err(&pdev->dev, "unable to register\n"); + goto dma_register_err; + } + return 0; + +dma_register_err: + of_dma_controller_free(pdev->dev.of_node); +err: + channel_num = i ? i - 1 : 0; + for (i = 0; i < channel_num; i++) { + struct rz_dmac_chan *channel = &dmac->channels[i]; + + dma_free_coherent(&pdev->dev, + sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC, + channel->lmdesc.base, + channel->lmdesc.base_dma); + } + + pm_runtime_put(&pdev->dev); +err_pm_disable: + pm_runtime_disable(&pdev->dev); + + return ret; +} + +static int rz_dmac_remove(struct platform_device *pdev) +{ + struct rz_dmac *dmac = platform_get_drvdata(pdev); + unsigned int i; + + for (i = 0; i < dmac->n_channels; i++) { + struct rz_dmac_chan *channel = &dmac->channels[i]; + + dma_free_coherent(&pdev->dev, + sizeof(struct rz_lmdesc) * DMAC_NR_LMDESC, + channel->lmdesc.base, + channel->lmdesc.base_dma); + } + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&dmac->engine); + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + return 0; +} + +static const struct of_device_id of_rz_dmac_match[] = { + { .compatible = "renesas,rz-dmac", }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, of_rz_dmac_match); + +static struct platform_driver rz_dmac_driver = { + .driver = { + .name = "rz-dmac", + .of_match_table = of_rz_dmac_match, + }, + .probe = rz_dmac_probe, + .remove = rz_dmac_remove, +}; + +module_platform_driver(rz_dmac_driver); + +MODULE_DESCRIPTION("Renesas RZ/G2L DMA Controller Driver"); +MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/dma/sh/shdma-arm.h b/drivers/dma/sh/shdma-arm.h new file mode 100644 index 000000000..7459f9a13 --- /dev/null +++ b/drivers/dma/sh/shdma-arm.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Renesas SuperH DMA Engine support + * + * Copyright (C) 2013 Renesas Electronics, Inc. + */ + +#ifndef SHDMA_ARM_H +#define SHDMA_ARM_H + +#include "shdma.h" + +/* Transmit sizes and respective CHCR register values */ +enum { + XMIT_SZ_8BIT = 0, + XMIT_SZ_16BIT = 1, + XMIT_SZ_32BIT = 2, + XMIT_SZ_64BIT = 7, + XMIT_SZ_128BIT = 3, + XMIT_SZ_256BIT = 4, + XMIT_SZ_512BIT = 5, +}; + +/* log2(size / 8) - used to calculate number of transfers */ +#define SH_DMAE_TS_SHIFT { \ + [XMIT_SZ_8BIT] = 0, \ + [XMIT_SZ_16BIT] = 1, \ + [XMIT_SZ_32BIT] = 2, \ + [XMIT_SZ_64BIT] = 3, \ + [XMIT_SZ_128BIT] = 4, \ + [XMIT_SZ_256BIT] = 5, \ + [XMIT_SZ_512BIT] = 6, \ +} + +#define TS_LOW_BIT 0x3 /* --xx */ +#define TS_HI_BIT 0xc /* xx-- */ + +#define TS_LOW_SHIFT (3) +#define TS_HI_SHIFT (20 - 2) /* 2 bits for shifted low TS */ + +#define TS_INDEX2VAL(i) \ + ((((i) & TS_LOW_BIT) << TS_LOW_SHIFT) |\ + (((i) & TS_HI_BIT) << TS_HI_SHIFT)) + +#define CHCR_TX(xmit_sz) (DM_FIX | SM_INC | RS_ERS | TS_INDEX2VAL((xmit_sz))) +#define CHCR_RX(xmit_sz) (DM_INC | SM_FIX | RS_ERS | TS_INDEX2VAL((xmit_sz))) + +#endif diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c new file mode 100644 index 000000000..158e5e7de --- /dev/null +++ b/drivers/dma/sh/shdma-base.c @@ -0,0 +1,1052 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Dmaengine driver base library for DMA controllers, found on SH-based SoCs + * + * extracted from shdma.c + * + * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de> + * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> + * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved. + * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved. + */ + +#include <linux/delay.h> +#include <linux/shdma-base.h> +#include <linux/dmaengine.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "../dmaengine.h" + +/* DMA descriptor control */ +enum shdma_desc_status { + DESC_IDLE, + DESC_PREPARED, + DESC_SUBMITTED, + DESC_COMPLETED, /* completed, have to call callback */ + DESC_WAITING, /* callback called, waiting for ack / re-submit */ +}; + +#define NR_DESCS_PER_CHANNEL 32 + +#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan) +#define to_shdma_dev(d) container_of(d, struct shdma_dev, dma_dev) + +/* + * For slave DMA we assume, that there is a finite number of DMA slaves in the + * system, and that each such slave can only use a finite number of channels. + * We use slave channel IDs to make sure, that no such slave channel ID is + * allocated more than once. + */ +static unsigned int slave_num = 256; +module_param(slave_num, uint, 0444); + +/* A bitmask with slave_num bits */ +static unsigned long *shdma_slave_used; + +/* Called under spin_lock_irq(&schan->chan_lock") */ +static void shdma_chan_xfer_ld_queue(struct shdma_chan *schan) +{ + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + struct shdma_desc *sdesc; + + /* DMA work check */ + if (ops->channel_busy(schan)) + return; + + /* Find the first not transferred descriptor */ + list_for_each_entry(sdesc, &schan->ld_queue, node) + if (sdesc->mark == DESC_SUBMITTED) { + ops->start_xfer(schan, sdesc); + break; + } +} + +static dma_cookie_t shdma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct shdma_desc *chunk, *c, *desc = + container_of(tx, struct shdma_desc, async_tx); + struct shdma_chan *schan = to_shdma_chan(tx->chan); + dma_async_tx_callback callback = tx->callback; + dma_cookie_t cookie; + bool power_up; + + spin_lock_irq(&schan->chan_lock); + + power_up = list_empty(&schan->ld_queue); + + cookie = dma_cookie_assign(tx); + + /* Mark all chunks of this descriptor as submitted, move to the queue */ + list_for_each_entry_safe(chunk, c, desc->node.prev, node) { + /* + * All chunks are on the global ld_free, so, we have to find + * the end of the chain ourselves + */ + if (chunk != desc && (chunk->mark == DESC_IDLE || + chunk->async_tx.cookie > 0 || + chunk->async_tx.cookie == -EBUSY || + &chunk->node == &schan->ld_free)) + break; + chunk->mark = DESC_SUBMITTED; + if (chunk->chunks == 1) { + chunk->async_tx.callback = callback; + chunk->async_tx.callback_param = tx->callback_param; + } else { + /* Callback goes to the last chunk */ + chunk->async_tx.callback = NULL; + } + chunk->cookie = cookie; + list_move_tail(&chunk->node, &schan->ld_queue); + + dev_dbg(schan->dev, "submit #%d@%p on %d\n", + tx->cookie, &chunk->async_tx, schan->id); + } + + if (power_up) { + int ret; + schan->pm_state = SHDMA_PM_BUSY; + + ret = pm_runtime_get(schan->dev); + + spin_unlock_irq(&schan->chan_lock); + if (ret < 0) + dev_err(schan->dev, "%s(): GET = %d\n", __func__, ret); + + pm_runtime_barrier(schan->dev); + + spin_lock_irq(&schan->chan_lock); + + /* Have we been reset, while waiting? */ + if (schan->pm_state != SHDMA_PM_ESTABLISHED) { + struct shdma_dev *sdev = + to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + dev_dbg(schan->dev, "Bring up channel %d\n", + schan->id); + /* + * TODO: .xfer_setup() might fail on some platforms. + * Make it int then, on error remove chunks from the + * queue again + */ + ops->setup_xfer(schan, schan->slave_id); + + if (schan->pm_state == SHDMA_PM_PENDING) + shdma_chan_xfer_ld_queue(schan); + schan->pm_state = SHDMA_PM_ESTABLISHED; + } + } else { + /* + * Tell .device_issue_pending() not to run the queue, interrupts + * will do it anyway + */ + schan->pm_state = SHDMA_PM_PENDING; + } + + spin_unlock_irq(&schan->chan_lock); + + return cookie; +} + +/* Called with desc_lock held */ +static struct shdma_desc *shdma_get_desc(struct shdma_chan *schan) +{ + struct shdma_desc *sdesc; + + list_for_each_entry(sdesc, &schan->ld_free, node) + if (sdesc->mark != DESC_PREPARED) { + BUG_ON(sdesc->mark != DESC_IDLE); + list_del(&sdesc->node); + return sdesc; + } + + return NULL; +} + +static int shdma_setup_slave(struct shdma_chan *schan, dma_addr_t slave_addr) +{ + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int ret, match; + + if (schan->dev->of_node) { + match = schan->hw_req; + ret = ops->set_slave(schan, match, slave_addr, true); + if (ret < 0) + return ret; + } else { + match = schan->real_slave_id; + } + + if (schan->real_slave_id < 0 || schan->real_slave_id >= slave_num) + return -EINVAL; + + if (test_and_set_bit(schan->real_slave_id, shdma_slave_used)) + return -EBUSY; + + ret = ops->set_slave(schan, match, slave_addr, false); + if (ret < 0) { + clear_bit(schan->real_slave_id, shdma_slave_used); + return ret; + } + + schan->slave_id = schan->real_slave_id; + + return 0; +} + +static int shdma_alloc_chan_resources(struct dma_chan *chan) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + struct shdma_desc *desc; + struct shdma_slave *slave = chan->private; + int ret, i; + + /* + * This relies on the guarantee from dmaengine that alloc_chan_resources + * never runs concurrently with itself or free_chan_resources. + */ + if (slave) { + /* Legacy mode: .private is set in filter */ + schan->real_slave_id = slave->slave_id; + ret = shdma_setup_slave(schan, 0); + if (ret < 0) + goto esetslave; + } else { + /* Normal mode: real_slave_id was set by filter */ + schan->slave_id = -EINVAL; + } + + schan->desc = kcalloc(NR_DESCS_PER_CHANNEL, + sdev->desc_size, GFP_KERNEL); + if (!schan->desc) { + ret = -ENOMEM; + goto edescalloc; + } + schan->desc_num = NR_DESCS_PER_CHANNEL; + + for (i = 0; i < NR_DESCS_PER_CHANNEL; i++) { + desc = ops->embedded_desc(schan->desc, i); + dma_async_tx_descriptor_init(&desc->async_tx, + &schan->dma_chan); + desc->async_tx.tx_submit = shdma_tx_submit; + desc->mark = DESC_IDLE; + + list_add(&desc->node, &schan->ld_free); + } + + return NR_DESCS_PER_CHANNEL; + +edescalloc: + if (slave) +esetslave: + clear_bit(slave->slave_id, shdma_slave_used); + chan->private = NULL; + return ret; +} + +/* + * This is the standard shdma filter function to be used as a replacement to the + * "old" method, using the .private pointer. + * You always have to pass a valid slave id as the argument, old drivers that + * pass ERR_PTR(-EINVAL) as a filter parameter and set it up in dma_slave_config + * need to be updated so we can remove the slave_id field from dma_slave_config. + * parameter. If this filter is used, the slave driver, after calling + * dma_request_channel(), will also have to call dmaengine_slave_config() with + * .direction, and either .src_addr or .dst_addr set. + * + * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE + * capability! If this becomes a requirement, hardware glue drivers, using this + * services would have to provide their own filters, which first would check + * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do + * this, and only then, in case of a match, call this common filter. + * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate(). + * In that case the MID-RID value is used for slave channel filtering and is + * passed to this function in the "arg" parameter. + */ +bool shdma_chan_filter(struct dma_chan *chan, void *arg) +{ + struct shdma_chan *schan; + struct shdma_dev *sdev; + int slave_id = (long)arg; + int ret; + + /* Only support channels handled by this driver. */ + if (chan->device->device_alloc_chan_resources != + shdma_alloc_chan_resources) + return false; + + schan = to_shdma_chan(chan); + sdev = to_shdma_dev(chan->device); + + /* + * For DT, the schan->slave_id field is generated by the + * set_slave function from the slave ID that is passed in + * from xlate. For the non-DT case, the slave ID is + * directly passed into the filter function by the driver + */ + if (schan->dev->of_node) { + ret = sdev->ops->set_slave(schan, slave_id, 0, true); + if (ret < 0) + return false; + + schan->real_slave_id = schan->slave_id; + return true; + } + + if (slave_id < 0) { + /* No slave requested - arbitrary channel */ + dev_warn(sdev->dma_dev.dev, "invalid slave ID passed to dma_request_slave\n"); + return true; + } + + if (slave_id >= slave_num) + return false; + + ret = sdev->ops->set_slave(schan, slave_id, 0, true); + if (ret < 0) + return false; + + schan->real_slave_id = slave_id; + + return true; +} +EXPORT_SYMBOL(shdma_chan_filter); + +static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) +{ + struct shdma_desc *desc, *_desc; + /* Is the "exposed" head of a chain acked? */ + bool head_acked = false; + dma_cookie_t cookie = 0; + dma_async_tx_callback callback = NULL; + struct dmaengine_desc_callback cb; + unsigned long flags; + LIST_HEAD(cyclic_list); + + memset(&cb, 0, sizeof(cb)); + spin_lock_irqsave(&schan->chan_lock, flags); + list_for_each_entry_safe(desc, _desc, &schan->ld_queue, node) { + struct dma_async_tx_descriptor *tx = &desc->async_tx; + + BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie); + BUG_ON(desc->mark != DESC_SUBMITTED && + desc->mark != DESC_COMPLETED && + desc->mark != DESC_WAITING); + + /* + * queue is ordered, and we use this loop to (1) clean up all + * completed descriptors, and to (2) update descriptor flags of + * any chunks in a (partially) completed chain + */ + if (!all && desc->mark == DESC_SUBMITTED && + desc->cookie != cookie) + break; + + if (tx->cookie > 0) + cookie = tx->cookie; + + if (desc->mark == DESC_COMPLETED && desc->chunks == 1) { + if (schan->dma_chan.completed_cookie != desc->cookie - 1) + dev_dbg(schan->dev, + "Completing cookie %d, expected %d\n", + desc->cookie, + schan->dma_chan.completed_cookie + 1); + schan->dma_chan.completed_cookie = desc->cookie; + } + + /* Call callback on the last chunk */ + if (desc->mark == DESC_COMPLETED && tx->callback) { + desc->mark = DESC_WAITING; + dmaengine_desc_get_callback(tx, &cb); + callback = tx->callback; + dev_dbg(schan->dev, "descriptor #%d@%p on %d callback\n", + tx->cookie, tx, schan->id); + BUG_ON(desc->chunks != 1); + break; + } + + if (tx->cookie > 0 || tx->cookie == -EBUSY) { + if (desc->mark == DESC_COMPLETED) { + BUG_ON(tx->cookie < 0); + desc->mark = DESC_WAITING; + } + head_acked = async_tx_test_ack(tx); + } else { + switch (desc->mark) { + case DESC_COMPLETED: + desc->mark = DESC_WAITING; + fallthrough; + case DESC_WAITING: + if (head_acked) + async_tx_ack(&desc->async_tx); + } + } + + dev_dbg(schan->dev, "descriptor %p #%d completed.\n", + tx, tx->cookie); + + if (((desc->mark == DESC_COMPLETED || + desc->mark == DESC_WAITING) && + async_tx_test_ack(&desc->async_tx)) || all) { + + if (all || !desc->cyclic) { + /* Remove from ld_queue list */ + desc->mark = DESC_IDLE; + list_move(&desc->node, &schan->ld_free); + } else { + /* reuse as cyclic */ + desc->mark = DESC_SUBMITTED; + list_move_tail(&desc->node, &cyclic_list); + } + + if (list_empty(&schan->ld_queue)) { + dev_dbg(schan->dev, "Bring down channel %d\n", schan->id); + pm_runtime_put(schan->dev); + schan->pm_state = SHDMA_PM_ESTABLISHED; + } else if (schan->pm_state == SHDMA_PM_PENDING) { + shdma_chan_xfer_ld_queue(schan); + } + } + } + + if (all && !callback) + /* + * Terminating and the loop completed normally: forgive + * uncompleted cookies + */ + schan->dma_chan.completed_cookie = schan->dma_chan.cookie; + + list_splice_tail(&cyclic_list, &schan->ld_queue); + + spin_unlock_irqrestore(&schan->chan_lock, flags); + + dmaengine_desc_callback_invoke(&cb, NULL); + + return callback; +} + +/* + * shdma_chan_ld_cleanup - Clean up link descriptors + * + * Clean up the ld_queue of DMA channel. + */ +static void shdma_chan_ld_cleanup(struct shdma_chan *schan, bool all) +{ + while (__ld_cleanup(schan, all)) + ; +} + +/* + * shdma_free_chan_resources - Free all resources of the channel. + */ +static void shdma_free_chan_resources(struct dma_chan *chan) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(chan->device); + const struct shdma_ops *ops = sdev->ops; + LIST_HEAD(list); + + /* Protect against ISR */ + spin_lock_irq(&schan->chan_lock); + ops->halt_channel(schan); + spin_unlock_irq(&schan->chan_lock); + + /* Now no new interrupts will occur */ + + /* Prepared and not submitted descriptors can still be on the queue */ + if (!list_empty(&schan->ld_queue)) + shdma_chan_ld_cleanup(schan, true); + + if (schan->slave_id >= 0) { + /* The caller is holding dma_list_mutex */ + clear_bit(schan->slave_id, shdma_slave_used); + chan->private = NULL; + } + + schan->real_slave_id = 0; + + spin_lock_irq(&schan->chan_lock); + + list_splice_init(&schan->ld_free, &list); + schan->desc_num = 0; + + spin_unlock_irq(&schan->chan_lock); + + kfree(schan->desc); +} + +/** + * shdma_add_desc - get, set up and return one transfer descriptor + * @schan: DMA channel + * @flags: DMA transfer flags + * @dst: destination DMA address, incremented when direction equals + * DMA_DEV_TO_MEM or DMA_MEM_TO_MEM + * @src: source DMA address, incremented when direction equals + * DMA_MEM_TO_DEV or DMA_MEM_TO_MEM + * @len: DMA transfer length + * @first: if NULL, set to the current descriptor and cookie set to -EBUSY + * @direction: needed for slave DMA to decide which address to keep constant, + * equals DMA_MEM_TO_MEM for MEMCPY + * Returns 0 or an error + * Locks: called with desc_lock held + */ +static struct shdma_desc *shdma_add_desc(struct shdma_chan *schan, + unsigned long flags, dma_addr_t *dst, dma_addr_t *src, size_t *len, + struct shdma_desc **first, enum dma_transfer_direction direction) +{ + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + struct shdma_desc *new; + size_t copy_size = *len; + + if (!copy_size) + return NULL; + + /* Allocate the link descriptor from the free list */ + new = shdma_get_desc(schan); + if (!new) { + dev_err(schan->dev, "No free link descriptor available\n"); + return NULL; + } + + ops->desc_setup(schan, new, *src, *dst, ©_size); + + if (!*first) { + /* First desc */ + new->async_tx.cookie = -EBUSY; + *first = new; + } else { + /* Other desc - invisible to the user */ + new->async_tx.cookie = -EINVAL; + } + + dev_dbg(schan->dev, + "chaining (%zu/%zu)@%pad -> %pad with %p, cookie %d\n", + copy_size, *len, src, dst, &new->async_tx, + new->async_tx.cookie); + + new->mark = DESC_PREPARED; + new->async_tx.flags = flags; + new->direction = direction; + new->partial = 0; + + *len -= copy_size; + if (direction == DMA_MEM_TO_MEM || direction == DMA_MEM_TO_DEV) + *src += copy_size; + if (direction == DMA_MEM_TO_MEM || direction == DMA_DEV_TO_MEM) + *dst += copy_size; + + return new; +} + +/* + * shdma_prep_sg - prepare transfer descriptors from an SG list + * + * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also + * converted to scatter-gather to guarantee consistent locking and a correct + * list manipulation. For slave DMA direction carries the usual meaning, and, + * logically, the SG list is RAM and the addr variable contains slave address, + * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM + * and the SG list contains only one element and points at the source buffer. + */ +static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan, + struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr, + enum dma_transfer_direction direction, unsigned long flags, bool cyclic) +{ + struct scatterlist *sg; + struct shdma_desc *first = NULL, *new = NULL /* compiler... */; + LIST_HEAD(tx_list); + int chunks = 0; + unsigned long irq_flags; + int i; + + for_each_sg(sgl, sg, sg_len, i) + chunks += DIV_ROUND_UP(sg_dma_len(sg), schan->max_xfer_len); + + /* Have to lock the whole loop to protect against concurrent release */ + spin_lock_irqsave(&schan->chan_lock, irq_flags); + + /* + * Chaining: + * first descriptor is what user is dealing with in all API calls, its + * cookie is at first set to -EBUSY, at tx-submit to a positive + * number + * if more than one chunk is needed further chunks have cookie = -EINVAL + * the last chunk, if not equal to the first, has cookie = -ENOSPC + * all chunks are linked onto the tx_list head with their .node heads + * only during this function, then they are immediately spliced + * back onto the free list in form of a chain + */ + for_each_sg(sgl, sg, sg_len, i) { + dma_addr_t sg_addr = sg_dma_address(sg); + size_t len = sg_dma_len(sg); + + if (!len) + goto err_get_desc; + + do { + dev_dbg(schan->dev, "Add SG #%d@%p[%zu], dma %pad\n", + i, sg, len, &sg_addr); + + if (direction == DMA_DEV_TO_MEM) + new = shdma_add_desc(schan, flags, + &sg_addr, addr, &len, &first, + direction); + else + new = shdma_add_desc(schan, flags, + addr, &sg_addr, &len, &first, + direction); + if (!new) + goto err_get_desc; + + new->cyclic = cyclic; + if (cyclic) + new->chunks = 1; + else + new->chunks = chunks--; + list_add_tail(&new->node, &tx_list); + } while (len); + } + + if (new != first) + new->async_tx.cookie = -ENOSPC; + + /* Put them back on the free list, so, they don't get lost */ + list_splice_tail(&tx_list, &schan->ld_free); + + spin_unlock_irqrestore(&schan->chan_lock, irq_flags); + + return &first->async_tx; + +err_get_desc: + list_for_each_entry(new, &tx_list, node) + new->mark = DESC_IDLE; + list_splice(&tx_list, &schan->ld_free); + + spin_unlock_irqrestore(&schan->chan_lock, irq_flags); + + return NULL; +} + +static struct dma_async_tx_descriptor *shdma_prep_memcpy( + struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src, + size_t len, unsigned long flags) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct scatterlist sg; + + if (!chan || !len) + return NULL; + + BUG_ON(!schan->desc_num); + + sg_init_table(&sg, 1); + sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len, + offset_in_page(dma_src)); + sg_dma_address(&sg) = dma_src; + sg_dma_len(&sg) = len; + + return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM, + flags, false); +} + +static struct dma_async_tx_descriptor *shdma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, + enum dma_transfer_direction direction, unsigned long flags, void *context) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int slave_id = schan->slave_id; + dma_addr_t slave_addr; + + if (!chan) + return NULL; + + BUG_ON(!schan->desc_num); + + /* Someone calling slave DMA on a generic channel? */ + if (slave_id < 0 || !sg_len) { + dev_warn(schan->dev, "%s: bad parameter: len=%d, id=%d\n", + __func__, sg_len, slave_id); + return NULL; + } + + slave_addr = ops->slave_addr(schan); + + return shdma_prep_sg(schan, sgl, sg_len, &slave_addr, + direction, flags, false); +} + +#define SHDMA_MAX_SG_LEN 32 + +static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + struct dma_async_tx_descriptor *desc; + const struct shdma_ops *ops = sdev->ops; + unsigned int sg_len = buf_len / period_len; + int slave_id = schan->slave_id; + dma_addr_t slave_addr; + struct scatterlist *sgl; + int i; + + if (!chan) + return NULL; + + BUG_ON(!schan->desc_num); + + if (sg_len > SHDMA_MAX_SG_LEN) { + dev_err(schan->dev, "sg length %d exceeds limit %d", + sg_len, SHDMA_MAX_SG_LEN); + return NULL; + } + + /* Someone calling slave DMA on a generic channel? */ + if (slave_id < 0 || (buf_len < period_len)) { + dev_warn(schan->dev, + "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", + __func__, buf_len, period_len, slave_id); + return NULL; + } + + slave_addr = ops->slave_addr(schan); + + /* + * Allocate the sg list dynamically as it would consumer too much stack + * space. + */ + sgl = kmalloc_array(sg_len, sizeof(*sgl), GFP_KERNEL); + if (!sgl) + return NULL; + + sg_init_table(sgl, sg_len); + + for (i = 0; i < sg_len; i++) { + dma_addr_t src = buf_addr + (period_len * i); + + sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, + offset_in_page(src)); + sg_dma_address(&sgl[i]) = src; + sg_dma_len(&sgl[i]) = period_len; + } + + desc = shdma_prep_sg(schan, sgl, sg_len, &slave_addr, + direction, flags, true); + + kfree(sgl); + return desc; +} + +static int shdma_terminate_all(struct dma_chan *chan) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(chan->device); + const struct shdma_ops *ops = sdev->ops; + unsigned long flags; + + spin_lock_irqsave(&schan->chan_lock, flags); + ops->halt_channel(schan); + + if (ops->get_partial && !list_empty(&schan->ld_queue)) { + /* Record partial transfer */ + struct shdma_desc *desc = list_first_entry(&schan->ld_queue, + struct shdma_desc, node); + desc->partial = ops->get_partial(schan, desc); + } + + spin_unlock_irqrestore(&schan->chan_lock, flags); + + shdma_chan_ld_cleanup(schan, true); + + return 0; +} + +static int shdma_config(struct dma_chan *chan, + struct dma_slave_config *config) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + + /* + * So far only .slave_id is used, but the slave drivers are + * encouraged to also set a transfer direction and an address. + */ + if (!config) + return -EINVAL; + + /* + * We could lock this, but you shouldn't be configuring the + * channel, while using it... + */ + return shdma_setup_slave(schan, + config->direction == DMA_DEV_TO_MEM ? + config->src_addr : config->dst_addr); +} + +static void shdma_issue_pending(struct dma_chan *chan) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + + spin_lock_irq(&schan->chan_lock); + if (schan->pm_state == SHDMA_PM_ESTABLISHED) + shdma_chan_xfer_ld_queue(schan); + else + schan->pm_state = SHDMA_PM_PENDING; + spin_unlock_irq(&schan->chan_lock); +} + +static enum dma_status shdma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + enum dma_status status; + unsigned long flags; + + shdma_chan_ld_cleanup(schan, false); + + spin_lock_irqsave(&schan->chan_lock, flags); + + status = dma_cookie_status(chan, cookie, txstate); + + /* + * If we don't find cookie on the queue, it has been aborted and we have + * to report error + */ + if (status != DMA_COMPLETE) { + struct shdma_desc *sdesc; + status = DMA_ERROR; + list_for_each_entry(sdesc, &schan->ld_queue, node) + if (sdesc->cookie == cookie) { + status = DMA_IN_PROGRESS; + break; + } + } + + spin_unlock_irqrestore(&schan->chan_lock, flags); + + return status; +} + +/* Called from error IRQ or NMI */ +bool shdma_reset(struct shdma_dev *sdev) +{ + const struct shdma_ops *ops = sdev->ops; + struct shdma_chan *schan; + unsigned int handled = 0; + int i; + + /* Reset all channels */ + shdma_for_each_chan(schan, sdev, i) { + struct shdma_desc *sdesc; + LIST_HEAD(dl); + + if (!schan) + continue; + + spin_lock(&schan->chan_lock); + + /* Stop the channel */ + ops->halt_channel(schan); + + list_splice_init(&schan->ld_queue, &dl); + + if (!list_empty(&dl)) { + dev_dbg(schan->dev, "Bring down channel %d\n", schan->id); + pm_runtime_put(schan->dev); + } + schan->pm_state = SHDMA_PM_ESTABLISHED; + + spin_unlock(&schan->chan_lock); + + /* Complete all */ + list_for_each_entry(sdesc, &dl, node) { + struct dma_async_tx_descriptor *tx = &sdesc->async_tx; + + sdesc->mark = DESC_IDLE; + dmaengine_desc_get_callback_invoke(tx, NULL); + } + + spin_lock(&schan->chan_lock); + list_splice(&dl, &schan->ld_free); + spin_unlock(&schan->chan_lock); + + handled++; + } + + return !!handled; +} +EXPORT_SYMBOL(shdma_reset); + +static irqreturn_t chan_irq(int irq, void *dev) +{ + struct shdma_chan *schan = dev; + const struct shdma_ops *ops = + to_shdma_dev(schan->dma_chan.device)->ops; + irqreturn_t ret; + + spin_lock(&schan->chan_lock); + + ret = ops->chan_irq(schan, irq) ? IRQ_WAKE_THREAD : IRQ_NONE; + + spin_unlock(&schan->chan_lock); + + return ret; +} + +static irqreturn_t chan_irqt(int irq, void *dev) +{ + struct shdma_chan *schan = dev; + const struct shdma_ops *ops = + to_shdma_dev(schan->dma_chan.device)->ops; + struct shdma_desc *sdesc; + + spin_lock_irq(&schan->chan_lock); + list_for_each_entry(sdesc, &schan->ld_queue, node) { + if (sdesc->mark == DESC_SUBMITTED && + ops->desc_completed(schan, sdesc)) { + dev_dbg(schan->dev, "done #%d@%p\n", + sdesc->async_tx.cookie, &sdesc->async_tx); + sdesc->mark = DESC_COMPLETED; + break; + } + } + /* Next desc */ + shdma_chan_xfer_ld_queue(schan); + spin_unlock_irq(&schan->chan_lock); + + shdma_chan_ld_cleanup(schan, false); + + return IRQ_HANDLED; +} + +int shdma_request_irq(struct shdma_chan *schan, int irq, + unsigned long flags, const char *name) +{ + int ret = devm_request_threaded_irq(schan->dev, irq, chan_irq, + chan_irqt, flags, name, schan); + + schan->irq = ret < 0 ? ret : irq; + + return ret; +} +EXPORT_SYMBOL(shdma_request_irq); + +void shdma_chan_probe(struct shdma_dev *sdev, + struct shdma_chan *schan, int id) +{ + schan->pm_state = SHDMA_PM_ESTABLISHED; + + /* reference struct dma_device */ + schan->dma_chan.device = &sdev->dma_dev; + dma_cookie_init(&schan->dma_chan); + + schan->dev = sdev->dma_dev.dev; + schan->id = id; + + if (!schan->max_xfer_len) + schan->max_xfer_len = PAGE_SIZE; + + spin_lock_init(&schan->chan_lock); + + /* Init descripter manage list */ + INIT_LIST_HEAD(&schan->ld_queue); + INIT_LIST_HEAD(&schan->ld_free); + + /* Add the channel to DMA device channel list */ + list_add_tail(&schan->dma_chan.device_node, + &sdev->dma_dev.channels); + sdev->schan[id] = schan; +} +EXPORT_SYMBOL(shdma_chan_probe); + +void shdma_chan_remove(struct shdma_chan *schan) +{ + list_del(&schan->dma_chan.device_node); +} +EXPORT_SYMBOL(shdma_chan_remove); + +int shdma_init(struct device *dev, struct shdma_dev *sdev, + int chan_num) +{ + struct dma_device *dma_dev = &sdev->dma_dev; + + /* + * Require all call-backs for now, they can trivially be made optional + * later as required + */ + if (!sdev->ops || + !sdev->desc_size || + !sdev->ops->embedded_desc || + !sdev->ops->start_xfer || + !sdev->ops->setup_xfer || + !sdev->ops->set_slave || + !sdev->ops->desc_setup || + !sdev->ops->slave_addr || + !sdev->ops->channel_busy || + !sdev->ops->halt_channel || + !sdev->ops->desc_completed) + return -EINVAL; + + sdev->schan = kcalloc(chan_num, sizeof(*sdev->schan), GFP_KERNEL); + if (!sdev->schan) + return -ENOMEM; + + INIT_LIST_HEAD(&dma_dev->channels); + + /* Common and MEMCPY operations */ + dma_dev->device_alloc_chan_resources + = shdma_alloc_chan_resources; + dma_dev->device_free_chan_resources = shdma_free_chan_resources; + dma_dev->device_prep_dma_memcpy = shdma_prep_memcpy; + dma_dev->device_tx_status = shdma_tx_status; + dma_dev->device_issue_pending = shdma_issue_pending; + + /* Compulsory for DMA_SLAVE fields */ + dma_dev->device_prep_slave_sg = shdma_prep_slave_sg; + dma_dev->device_prep_dma_cyclic = shdma_prep_dma_cyclic; + dma_dev->device_config = shdma_config; + dma_dev->device_terminate_all = shdma_terminate_all; + + dma_dev->dev = dev; + + return 0; +} +EXPORT_SYMBOL(shdma_init); + +void shdma_cleanup(struct shdma_dev *sdev) +{ + kfree(sdev->schan); +} +EXPORT_SYMBOL(shdma_cleanup); + +static int __init shdma_enter(void) +{ + shdma_slave_used = bitmap_zalloc(slave_num, GFP_KERNEL); + if (!shdma_slave_used) + return -ENOMEM; + return 0; +} +module_init(shdma_enter); + +static void __exit shdma_exit(void) +{ + bitmap_free(shdma_slave_used); +} +module_exit(shdma_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("SH-DMA driver base library"); +MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>"); diff --git a/drivers/dma/sh/shdma.h b/drivers/dma/sh/shdma.h new file mode 100644 index 000000000..9c121a4b3 --- /dev/null +++ b/drivers/dma/sh/shdma.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Renesas SuperH DMA Engine support + * + * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> + * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved. + * + */ +#ifndef __DMA_SHDMA_H +#define __DMA_SHDMA_H + +#include <linux/sh_dma.h> +#include <linux/shdma-base.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/list.h> + +#define SH_DMAE_MAX_CHANNELS 20 +#define SH_DMAE_TCR_MAX 0x00FFFFFF /* 16MB */ + +struct device; + +struct sh_dmae_chan { + struct shdma_chan shdma_chan; + const struct sh_dmae_slave_config *config; /* Slave DMA configuration */ + int xmit_shift; /* log_2(bytes_per_xfer) */ + void __iomem *base; + char dev_id[16]; /* unique name per DMAC of channel */ + int pm_error; + dma_addr_t slave_addr; +}; + +struct sh_dmae_device { + struct shdma_dev shdma_dev; + struct sh_dmae_chan *chan[SH_DMAE_MAX_CHANNELS]; + const struct sh_dmae_pdata *pdata; + struct list_head node; + void __iomem *chan_reg; + void __iomem *dmars; + unsigned int chcr_offset; + u32 chcr_ie_bit; +}; + +struct sh_dmae_regs { + u32 sar; /* SAR / source address */ + u32 dar; /* DAR / destination address */ + u32 tcr; /* TCR / transfer count */ +}; + +struct sh_dmae_desc { + struct sh_dmae_regs hw; + struct shdma_desc shdma_desc; +}; + +#define to_sh_chan(chan) container_of(chan, struct sh_dmae_chan, shdma_chan) +#define to_sh_desc(lh) container_of(lh, struct sh_desc, node) +#define tx_to_sh_desc(tx) container_of(tx, struct sh_desc, async_tx) +#define to_sh_dev(chan) container_of(chan->shdma_chan.dma_chan.device,\ + struct sh_dmae_device, shdma_dev.dma_dev) + +#endif /* __DMA_SHDMA_H */ diff --git a/drivers/dma/sh/shdmac.c b/drivers/dma/sh/shdmac.c new file mode 100644 index 000000000..5aafe548c --- /dev/null +++ b/drivers/dma/sh/shdmac.c @@ -0,0 +1,938 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Renesas SuperH DMA Engine support + * + * base is drivers/dma/flsdma.c + * + * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de> + * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> + * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved. + * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved. + * + * - DMA of SuperH does not have Hardware DMA chain mode. + * - MAX DMA size is 16MB. + * + */ + +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kdebug.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/rculist.h> +#include <linux/sh_dma.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "../dmaengine.h" +#include "shdma.h" + +/* DMA registers */ +#define SAR 0x00 /* Source Address Register */ +#define DAR 0x04 /* Destination Address Register */ +#define TCR 0x08 /* Transfer Count Register */ +#define CHCR 0x0C /* Channel Control Register */ +#define DMAOR 0x40 /* DMA Operation Register */ + +#define TEND 0x18 /* USB-DMAC */ + +#define SH_DMAE_DRV_NAME "sh-dma-engine" + +/* Default MEMCPY transfer size = 2^2 = 4 bytes */ +#define LOG2_DEFAULT_XFER_SIZE 2 +#define SH_DMA_SLAVE_NUMBER 256 +#define SH_DMA_TCR_MAX (16 * 1024 * 1024 - 1) + +/* + * Used for write-side mutual exclusion for the global device list, + * read-side synchronization by way of RCU, and per-controller data. + */ +static DEFINE_SPINLOCK(sh_dmae_lock); +static LIST_HEAD(sh_dmae_devices); + +/* + * Different DMAC implementations provide different ways to clear DMA channels: + * (1) none - no CHCLR registers are available + * (2) one CHCLR register per channel - 0 has to be written to it to clear + * channel buffers + * (3) one CHCLR per several channels - 1 has to be written to the bit, + * corresponding to the specific channel to reset it + */ +static void channel_clear(struct sh_dmae_chan *sh_dc) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_dc); + const struct sh_dmae_channel *chan_pdata = shdev->pdata->channel + + sh_dc->shdma_chan.id; + u32 val = shdev->pdata->chclr_bitwise ? 1 << chan_pdata->chclr_bit : 0; + + __raw_writel(val, shdev->chan_reg + chan_pdata->chclr_offset); +} + +static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg) +{ + __raw_writel(data, sh_dc->base + reg); +} + +static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg) +{ + return __raw_readl(sh_dc->base + reg); +} + +static u16 dmaor_read(struct sh_dmae_device *shdev) +{ + void __iomem *addr = shdev->chan_reg + DMAOR; + + if (shdev->pdata->dmaor_is_32bit) + return __raw_readl(addr); + else + return __raw_readw(addr); +} + +static void dmaor_write(struct sh_dmae_device *shdev, u16 data) +{ + void __iomem *addr = shdev->chan_reg + DMAOR; + + if (shdev->pdata->dmaor_is_32bit) + __raw_writel(data, addr); + else + __raw_writew(data, addr); +} + +static void chcr_write(struct sh_dmae_chan *sh_dc, u32 data) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_dc); + + __raw_writel(data, sh_dc->base + shdev->chcr_offset); +} + +static u32 chcr_read(struct sh_dmae_chan *sh_dc) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_dc); + + return __raw_readl(sh_dc->base + shdev->chcr_offset); +} + +/* + * Reset DMA controller + * + * SH7780 has two DMAOR register + */ +static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev) +{ + unsigned short dmaor; + unsigned long flags; + + spin_lock_irqsave(&sh_dmae_lock, flags); + + dmaor = dmaor_read(shdev); + dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME)); + + spin_unlock_irqrestore(&sh_dmae_lock, flags); +} + +static int sh_dmae_rst(struct sh_dmae_device *shdev) +{ + unsigned short dmaor; + unsigned long flags; + + spin_lock_irqsave(&sh_dmae_lock, flags); + + dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME); + + if (shdev->pdata->chclr_present) { + int i; + for (i = 0; i < shdev->pdata->channel_num; i++) { + struct sh_dmae_chan *sh_chan = shdev->chan[i]; + if (sh_chan) + channel_clear(sh_chan); + } + } + + dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init); + + dmaor = dmaor_read(shdev); + + spin_unlock_irqrestore(&sh_dmae_lock, flags); + + if (dmaor & (DMAOR_AE | DMAOR_NMIF)) { + dev_warn(shdev->shdma_dev.dma_dev.dev, "Can't initialize DMAOR.\n"); + return -EIO; + } + if (shdev->pdata->dmaor_init & ~dmaor) + dev_warn(shdev->shdma_dev.dma_dev.dev, + "DMAOR=0x%x hasn't latched the initial value 0x%x.\n", + dmaor, shdev->pdata->dmaor_init); + return 0; +} + +static bool dmae_is_busy(struct sh_dmae_chan *sh_chan) +{ + u32 chcr = chcr_read(sh_chan); + + if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE) + return true; /* working */ + + return false; /* waiting */ +} + +static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + const struct sh_dmae_pdata *pdata = shdev->pdata; + int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) | + ((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift); + + if (cnt >= pdata->ts_shift_num) + cnt = 0; + + return pdata->ts_shift[cnt]; +} + +static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + const struct sh_dmae_pdata *pdata = shdev->pdata; + int i; + + for (i = 0; i < pdata->ts_shift_num; i++) + if (pdata->ts_shift[i] == l2size) + break; + + if (i == pdata->ts_shift_num) + i = 0; + + return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) | + ((i << pdata->ts_high_shift) & pdata->ts_high_mask); +} + +static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw) +{ + sh_dmae_writel(sh_chan, hw->sar, SAR); + sh_dmae_writel(sh_chan, hw->dar, DAR); + sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR); +} + +static void dmae_start(struct sh_dmae_chan *sh_chan) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + u32 chcr = chcr_read(sh_chan); + + if (shdev->pdata->needs_tend_set) + sh_dmae_writel(sh_chan, 0xFFFFFFFF, TEND); + + chcr |= CHCR_DE | shdev->chcr_ie_bit; + chcr_write(sh_chan, chcr & ~CHCR_TE); +} + +static void dmae_init(struct sh_dmae_chan *sh_chan) +{ + /* + * Default configuration for dual address memory-memory transfer. + */ + u32 chcr = DM_INC | SM_INC | RS_AUTO | log2size_to_chcr(sh_chan, + LOG2_DEFAULT_XFER_SIZE); + sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr); + chcr_write(sh_chan, chcr); +} + +static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val) +{ + /* If DMA is active, cannot set CHCR. TODO: remove this superfluous check */ + if (dmae_is_busy(sh_chan)) + return -EBUSY; + + sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val); + chcr_write(sh_chan, val); + + return 0; +} + +static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + const struct sh_dmae_pdata *pdata = shdev->pdata; + const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->shdma_chan.id]; + void __iomem *addr = shdev->dmars; + unsigned int shift = chan_pdata->dmars_bit; + + if (dmae_is_busy(sh_chan)) + return -EBUSY; + + if (pdata->no_dmars) + return 0; + + /* in the case of a missing DMARS resource use first memory window */ + if (!addr) + addr = shdev->chan_reg; + addr += chan_pdata->dmars; + + __raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift), + addr); + + return 0; +} + +static void sh_dmae_start_xfer(struct shdma_chan *schan, + struct shdma_desc *sdesc) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + struct sh_dmae_desc *sh_desc = container_of(sdesc, + struct sh_dmae_desc, shdma_desc); + dev_dbg(sh_chan->shdma_chan.dev, "Queue #%d to %d: %u@%x -> %x\n", + sdesc->async_tx.cookie, sh_chan->shdma_chan.id, + sh_desc->hw.tcr, sh_desc->hw.sar, sh_desc->hw.dar); + /* Get the ld start address from ld_queue */ + dmae_set_reg(sh_chan, &sh_desc->hw); + dmae_start(sh_chan); +} + +static bool sh_dmae_channel_busy(struct shdma_chan *schan) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + return dmae_is_busy(sh_chan); +} + +static void sh_dmae_setup_xfer(struct shdma_chan *schan, + int slave_id) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + + if (slave_id >= 0) { + const struct sh_dmae_slave_config *cfg = + sh_chan->config; + + dmae_set_dmars(sh_chan, cfg->mid_rid); + dmae_set_chcr(sh_chan, cfg->chcr); + } else { + dmae_init(sh_chan); + } +} + +/* + * Find a slave channel configuration from the contoller list by either a slave + * ID in the non-DT case, or by a MID/RID value in the DT case + */ +static const struct sh_dmae_slave_config *dmae_find_slave( + struct sh_dmae_chan *sh_chan, int match) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + const struct sh_dmae_pdata *pdata = shdev->pdata; + const struct sh_dmae_slave_config *cfg; + int i; + + if (!sh_chan->shdma_chan.dev->of_node) { + if (match >= SH_DMA_SLAVE_NUMBER) + return NULL; + + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) + if (cfg->slave_id == match) + return cfg; + } else { + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) + if (cfg->mid_rid == match) { + sh_chan->shdma_chan.slave_id = i; + return cfg; + } + } + + return NULL; +} + +static int sh_dmae_set_slave(struct shdma_chan *schan, + int slave_id, dma_addr_t slave_addr, bool try) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + const struct sh_dmae_slave_config *cfg = dmae_find_slave(sh_chan, slave_id); + if (!cfg) + return -ENXIO; + + if (!try) { + sh_chan->config = cfg; + sh_chan->slave_addr = slave_addr ? : cfg->addr; + } + + return 0; +} + +static void dmae_halt(struct sh_dmae_chan *sh_chan) +{ + struct sh_dmae_device *shdev = to_sh_dev(sh_chan); + u32 chcr = chcr_read(sh_chan); + + chcr &= ~(CHCR_DE | CHCR_TE | shdev->chcr_ie_bit); + chcr_write(sh_chan, chcr); +} + +static int sh_dmae_desc_setup(struct shdma_chan *schan, + struct shdma_desc *sdesc, + dma_addr_t src, dma_addr_t dst, size_t *len) +{ + struct sh_dmae_desc *sh_desc = container_of(sdesc, + struct sh_dmae_desc, shdma_desc); + + if (*len > schan->max_xfer_len) + *len = schan->max_xfer_len; + + sh_desc->hw.sar = src; + sh_desc->hw.dar = dst; + sh_desc->hw.tcr = *len; + + return 0; +} + +static void sh_dmae_halt(struct shdma_chan *schan) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + dmae_halt(sh_chan); +} + +static bool sh_dmae_chan_irq(struct shdma_chan *schan, int irq) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + + if (!(chcr_read(sh_chan) & CHCR_TE)) + return false; + + /* DMA stop */ + dmae_halt(sh_chan); + + return true; +} + +static size_t sh_dmae_get_partial(struct shdma_chan *schan, + struct shdma_desc *sdesc) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, + shdma_chan); + struct sh_dmae_desc *sh_desc = container_of(sdesc, + struct sh_dmae_desc, shdma_desc); + return sh_desc->hw.tcr - + (sh_dmae_readl(sh_chan, TCR) << sh_chan->xmit_shift); +} + +/* Called from error IRQ or NMI */ +static bool sh_dmae_reset(struct sh_dmae_device *shdev) +{ + bool ret; + + /* halt the dma controller */ + sh_dmae_ctl_stop(shdev); + + /* We cannot detect, which channel caused the error, have to reset all */ + ret = shdma_reset(&shdev->shdma_dev); + + sh_dmae_rst(shdev); + + return ret; +} + +static irqreturn_t sh_dmae_err(int irq, void *data) +{ + struct sh_dmae_device *shdev = data; + + if (!(dmaor_read(shdev) & DMAOR_AE)) + return IRQ_NONE; + + sh_dmae_reset(shdev); + return IRQ_HANDLED; +} + +static bool sh_dmae_desc_completed(struct shdma_chan *schan, + struct shdma_desc *sdesc) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, + struct sh_dmae_chan, shdma_chan); + struct sh_dmae_desc *sh_desc = container_of(sdesc, + struct sh_dmae_desc, shdma_desc); + u32 sar_buf = sh_dmae_readl(sh_chan, SAR); + u32 dar_buf = sh_dmae_readl(sh_chan, DAR); + + return (sdesc->direction == DMA_DEV_TO_MEM && + (sh_desc->hw.dar + sh_desc->hw.tcr) == dar_buf) || + (sdesc->direction != DMA_DEV_TO_MEM && + (sh_desc->hw.sar + sh_desc->hw.tcr) == sar_buf); +} + +static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev) +{ + /* Fast path out if NMIF is not asserted for this controller */ + if ((dmaor_read(shdev) & DMAOR_NMIF) == 0) + return false; + + return sh_dmae_reset(shdev); +} + +static int sh_dmae_nmi_handler(struct notifier_block *self, + unsigned long cmd, void *data) +{ + struct sh_dmae_device *shdev; + int ret = NOTIFY_DONE; + bool triggered; + + /* + * Only concern ourselves with NMI events. + * + * Normally we would check the die chain value, but as this needs + * to be architecture independent, check for NMI context instead. + */ + if (!in_nmi()) + return NOTIFY_DONE; + + rcu_read_lock(); + list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) { + /* + * Only stop if one of the controllers has NMIF asserted, + * we do not want to interfere with regular address error + * handling or NMI events that don't concern the DMACs. + */ + triggered = sh_dmae_nmi_notify(shdev); + if (triggered == true) + ret = NOTIFY_OK; + } + rcu_read_unlock(); + + return ret; +} + +static struct notifier_block sh_dmae_nmi_notifier __read_mostly = { + .notifier_call = sh_dmae_nmi_handler, + + /* Run before NMI debug handler and KGDB */ + .priority = 1, +}; + +static int sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id, + int irq, unsigned long flags) +{ + const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id]; + struct shdma_dev *sdev = &shdev->shdma_dev; + struct platform_device *pdev = to_platform_device(sdev->dma_dev.dev); + struct sh_dmae_chan *sh_chan; + struct shdma_chan *schan; + int err; + + sh_chan = devm_kzalloc(sdev->dma_dev.dev, sizeof(struct sh_dmae_chan), + GFP_KERNEL); + if (!sh_chan) + return -ENOMEM; + + schan = &sh_chan->shdma_chan; + schan->max_xfer_len = SH_DMA_TCR_MAX + 1; + + shdma_chan_probe(sdev, schan, id); + + sh_chan->base = shdev->chan_reg + chan_pdata->offset; + + /* set up channel irq */ + if (pdev->id >= 0) + snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id), + "sh-dmae%d.%d", pdev->id, id); + else + snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id), + "sh-dma%d", id); + + err = shdma_request_irq(schan, irq, flags, sh_chan->dev_id); + if (err) { + dev_err(sdev->dma_dev.dev, + "DMA channel %d request_irq error %d\n", + id, err); + goto err_no_irq; + } + + shdev->chan[id] = sh_chan; + return 0; + +err_no_irq: + /* remove from dmaengine device node */ + shdma_chan_remove(schan); + return err; +} + +static void sh_dmae_chan_remove(struct sh_dmae_device *shdev) +{ + struct shdma_chan *schan; + int i; + + shdma_for_each_chan(schan, &shdev->shdma_dev, i) { + BUG_ON(!schan); + + shdma_chan_remove(schan); + } +} + +#ifdef CONFIG_PM +static int sh_dmae_runtime_suspend(struct device *dev) +{ + struct sh_dmae_device *shdev = dev_get_drvdata(dev); + + sh_dmae_ctl_stop(shdev); + return 0; +} + +static int sh_dmae_runtime_resume(struct device *dev) +{ + struct sh_dmae_device *shdev = dev_get_drvdata(dev); + + return sh_dmae_rst(shdev); +} +#endif + +#ifdef CONFIG_PM_SLEEP +static int sh_dmae_suspend(struct device *dev) +{ + struct sh_dmae_device *shdev = dev_get_drvdata(dev); + + sh_dmae_ctl_stop(shdev); + return 0; +} + +static int sh_dmae_resume(struct device *dev) +{ + struct sh_dmae_device *shdev = dev_get_drvdata(dev); + int i, ret; + + ret = sh_dmae_rst(shdev); + if (ret < 0) + dev_err(dev, "Failed to reset!\n"); + + for (i = 0; i < shdev->pdata->channel_num; i++) { + struct sh_dmae_chan *sh_chan = shdev->chan[i]; + + if (!sh_chan->shdma_chan.desc_num) + continue; + + if (sh_chan->shdma_chan.slave_id >= 0) { + const struct sh_dmae_slave_config *cfg = sh_chan->config; + dmae_set_dmars(sh_chan, cfg->mid_rid); + dmae_set_chcr(sh_chan, cfg->chcr); + } else { + dmae_init(sh_chan); + } + } + + return 0; +} +#endif + +static const struct dev_pm_ops sh_dmae_pm = { + SET_SYSTEM_SLEEP_PM_OPS(sh_dmae_suspend, sh_dmae_resume) + SET_RUNTIME_PM_OPS(sh_dmae_runtime_suspend, sh_dmae_runtime_resume, + NULL) +}; + +static dma_addr_t sh_dmae_slave_addr(struct shdma_chan *schan) +{ + struct sh_dmae_chan *sh_chan = container_of(schan, + struct sh_dmae_chan, shdma_chan); + + /* + * Implicit BUG_ON(!sh_chan->config) + * This is an exclusive slave DMA operation, may only be called after a + * successful slave configuration. + */ + return sh_chan->slave_addr; +} + +static struct shdma_desc *sh_dmae_embedded_desc(void *buf, int i) +{ + return &((struct sh_dmae_desc *)buf)[i].shdma_desc; +} + +static const struct shdma_ops sh_dmae_shdma_ops = { + .desc_completed = sh_dmae_desc_completed, + .halt_channel = sh_dmae_halt, + .channel_busy = sh_dmae_channel_busy, + .slave_addr = sh_dmae_slave_addr, + .desc_setup = sh_dmae_desc_setup, + .set_slave = sh_dmae_set_slave, + .setup_xfer = sh_dmae_setup_xfer, + .start_xfer = sh_dmae_start_xfer, + .embedded_desc = sh_dmae_embedded_desc, + .chan_irq = sh_dmae_chan_irq, + .get_partial = sh_dmae_get_partial, +}; + +static int sh_dmae_probe(struct platform_device *pdev) +{ + const enum dma_slave_buswidth widths = + DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | + DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES | + DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES; + const struct sh_dmae_pdata *pdata; + unsigned long chan_flag[SH_DMAE_MAX_CHANNELS] = {}; + int chan_irq[SH_DMAE_MAX_CHANNELS]; + unsigned long irqflags = 0; + int err, errirq, i, irq_cnt = 0, irqres = 0, irq_cap = 0; + struct sh_dmae_device *shdev; + struct dma_device *dma_dev; + struct resource *chan, *dmars, *errirq_res, *chanirq_res; + + if (pdev->dev.of_node) + pdata = of_device_get_match_data(&pdev->dev); + else + pdata = dev_get_platdata(&pdev->dev); + + /* get platform data */ + if (!pdata || !pdata->channel_num) + return -ENODEV; + + chan = platform_get_resource(pdev, IORESOURCE_MEM, 0); + /* DMARS area is optional */ + dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1); + /* + * IRQ resources: + * 1. there always must be at least one IRQ IO-resource. On SH4 it is + * the error IRQ, in which case it is the only IRQ in this resource: + * start == end. If it is the only IRQ resource, all channels also + * use the same IRQ. + * 2. DMA channel IRQ resources can be specified one per resource or in + * ranges (start != end) + * 3. iff all events (channels and, optionally, error) on this + * controller use the same IRQ, only one IRQ resource can be + * specified, otherwise there must be one IRQ per channel, even if + * some of them are equal + * 4. if all IRQs on this controller are equal or if some specific IRQs + * specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be + * requested with the IRQF_SHARED flag + */ + errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!chan || !errirq_res) + return -ENODEV; + + shdev = devm_kzalloc(&pdev->dev, sizeof(struct sh_dmae_device), + GFP_KERNEL); + if (!shdev) + return -ENOMEM; + + dma_dev = &shdev->shdma_dev.dma_dev; + + shdev->chan_reg = devm_ioremap_resource(&pdev->dev, chan); + if (IS_ERR(shdev->chan_reg)) + return PTR_ERR(shdev->chan_reg); + if (dmars) { + shdev->dmars = devm_ioremap_resource(&pdev->dev, dmars); + if (IS_ERR(shdev->dmars)) + return PTR_ERR(shdev->dmars); + } + + dma_dev->src_addr_widths = widths; + dma_dev->dst_addr_widths = widths; + dma_dev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + + if (!pdata->slave_only) + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); + if (pdata->slave && pdata->slave_num) + dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); + + /* Default transfer size of 32 bytes requires 32-byte alignment */ + dma_dev->copy_align = LOG2_DEFAULT_XFER_SIZE; + + shdev->shdma_dev.ops = &sh_dmae_shdma_ops; + shdev->shdma_dev.desc_size = sizeof(struct sh_dmae_desc); + err = shdma_init(&pdev->dev, &shdev->shdma_dev, + pdata->channel_num); + if (err < 0) + goto eshdma; + + /* platform data */ + shdev->pdata = pdata; + + if (pdata->chcr_offset) + shdev->chcr_offset = pdata->chcr_offset; + else + shdev->chcr_offset = CHCR; + + if (pdata->chcr_ie_bit) + shdev->chcr_ie_bit = pdata->chcr_ie_bit; + else + shdev->chcr_ie_bit = CHCR_IE; + + platform_set_drvdata(pdev, shdev); + + pm_runtime_enable(&pdev->dev); + err = pm_runtime_get_sync(&pdev->dev); + if (err < 0) + dev_err(&pdev->dev, "%s(): GET = %d\n", __func__, err); + + spin_lock_irq(&sh_dmae_lock); + list_add_tail_rcu(&shdev->node, &sh_dmae_devices); + spin_unlock_irq(&sh_dmae_lock); + + /* reset dma controller - only needed as a test */ + err = sh_dmae_rst(shdev); + if (err) + goto rst_err; + + if (IS_ENABLED(CONFIG_CPU_SH4) || IS_ENABLED(CONFIG_ARCH_RENESAS)) { + chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1); + + if (!chanirq_res) + chanirq_res = errirq_res; + else + irqres++; + + if (chanirq_res == errirq_res || + (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE) + irqflags = IRQF_SHARED; + + errirq = errirq_res->start; + + err = devm_request_irq(&pdev->dev, errirq, sh_dmae_err, + irqflags, "DMAC Address Error", shdev); + if (err) { + dev_err(&pdev->dev, + "DMA failed requesting irq #%d, error %d\n", + errirq, err); + goto eirq_err; + } + } else { + chanirq_res = errirq_res; + } + + if (chanirq_res->start == chanirq_res->end && + !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) { + /* Special case - all multiplexed */ + for (; irq_cnt < pdata->channel_num; irq_cnt++) { + if (irq_cnt < SH_DMAE_MAX_CHANNELS) { + chan_irq[irq_cnt] = chanirq_res->start; + chan_flag[irq_cnt] = IRQF_SHARED; + } else { + irq_cap = 1; + break; + } + } + } else { + do { + for (i = chanirq_res->start; i <= chanirq_res->end; i++) { + if (irq_cnt >= SH_DMAE_MAX_CHANNELS) { + irq_cap = 1; + break; + } + + if ((errirq_res->flags & IORESOURCE_BITS) == + IORESOURCE_IRQ_SHAREABLE) + chan_flag[irq_cnt] = IRQF_SHARED; + else + chan_flag[irq_cnt] = 0; + dev_dbg(&pdev->dev, + "Found IRQ %d for channel %d\n", + i, irq_cnt); + chan_irq[irq_cnt++] = i; + } + + if (irq_cnt >= SH_DMAE_MAX_CHANNELS) + break; + + chanirq_res = platform_get_resource(pdev, + IORESOURCE_IRQ, ++irqres); + } while (irq_cnt < pdata->channel_num && chanirq_res); + } + + /* Create DMA Channel */ + for (i = 0; i < irq_cnt; i++) { + err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]); + if (err) + goto chan_probe_err; + } + + if (irq_cap) + dev_notice(&pdev->dev, "Attempting to register %d DMA " + "channels when a maximum of %d are supported.\n", + pdata->channel_num, SH_DMAE_MAX_CHANNELS); + + pm_runtime_put(&pdev->dev); + + err = dma_async_device_register(&shdev->shdma_dev.dma_dev); + if (err < 0) + goto edmadevreg; + + return err; + +edmadevreg: + pm_runtime_get(&pdev->dev); + +chan_probe_err: + sh_dmae_chan_remove(shdev); + +eirq_err: +rst_err: + spin_lock_irq(&sh_dmae_lock); + list_del_rcu(&shdev->node); + spin_unlock_irq(&sh_dmae_lock); + + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + shdma_cleanup(&shdev->shdma_dev); +eshdma: + synchronize_rcu(); + + return err; +} + +static int sh_dmae_remove(struct platform_device *pdev) +{ + struct sh_dmae_device *shdev = platform_get_drvdata(pdev); + struct dma_device *dma_dev = &shdev->shdma_dev.dma_dev; + + dma_async_device_unregister(dma_dev); + + spin_lock_irq(&sh_dmae_lock); + list_del_rcu(&shdev->node); + spin_unlock_irq(&sh_dmae_lock); + + pm_runtime_disable(&pdev->dev); + + sh_dmae_chan_remove(shdev); + shdma_cleanup(&shdev->shdma_dev); + + synchronize_rcu(); + + return 0; +} + +static struct platform_driver sh_dmae_driver = { + .driver = { + .pm = &sh_dmae_pm, + .name = SH_DMAE_DRV_NAME, + }, + .remove = sh_dmae_remove, +}; + +static int __init sh_dmae_init(void) +{ + /* Wire up NMI handling */ + int err = register_die_notifier(&sh_dmae_nmi_notifier); + if (err) + return err; + + return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe); +} +module_init(sh_dmae_init); + +static void __exit sh_dmae_exit(void) +{ + platform_driver_unregister(&sh_dmae_driver); + + unregister_die_notifier(&sh_dmae_nmi_notifier); +} +module_exit(sh_dmae_exit); + +MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>"); +MODULE_DESCRIPTION("Renesas SH DMA Engine driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" SH_DMAE_DRV_NAME); diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c new file mode 100644 index 000000000..5edaeb89d --- /dev/null +++ b/drivers/dma/sh/usb-dmac.c @@ -0,0 +1,914 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas USB DMA Controller Driver + * + * Copyright (C) 2015 Renesas Electronics Corporation + * + * based on rcar-dmac.c + * Copyright (C) 2014 Renesas Electronics Inc. + * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> + */ + +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "../dmaengine.h" +#include "../virt-dma.h" + +/* + * struct usb_dmac_sg - Descriptor for a hardware transfer + * @mem_addr: memory address + * @size: transfer size in bytes + */ +struct usb_dmac_sg { + dma_addr_t mem_addr; + u32 size; +}; + +/* + * struct usb_dmac_desc - USB DMA Transfer Descriptor + * @vd: base virtual channel DMA transaction descriptor + * @direction: direction of the DMA transfer + * @sg_allocated_len: length of allocated sg + * @sg_len: length of sg + * @sg_index: index of sg + * @residue: residue after the DMAC completed a transfer + * @node: node for desc_got and desc_freed + * @done_cookie: cookie after the DMAC completed a transfer + * @sg: information for the transfer + */ +struct usb_dmac_desc { + struct virt_dma_desc vd; + enum dma_transfer_direction direction; + unsigned int sg_allocated_len; + unsigned int sg_len; + unsigned int sg_index; + u32 residue; + struct list_head node; + dma_cookie_t done_cookie; + struct usb_dmac_sg sg[]; +}; + +#define to_usb_dmac_desc(vd) container_of(vd, struct usb_dmac_desc, vd) + +/* + * struct usb_dmac_chan - USB DMA Controller Channel + * @vc: base virtual DMA channel object + * @iomem: channel I/O memory base + * @index: index of this channel in the controller + * @irq: irq number of this channel + * @desc: the current descriptor + * @descs_allocated: number of descriptors allocated + * @desc_got: got descriptors + * @desc_freed: freed descriptors after the DMAC completed a transfer + */ +struct usb_dmac_chan { + struct virt_dma_chan vc; + void __iomem *iomem; + unsigned int index; + int irq; + struct usb_dmac_desc *desc; + int descs_allocated; + struct list_head desc_got; + struct list_head desc_freed; +}; + +#define to_usb_dmac_chan(c) container_of(c, struct usb_dmac_chan, vc.chan) + +/* + * struct usb_dmac - USB DMA Controller + * @engine: base DMA engine object + * @dev: the hardware device + * @iomem: remapped I/O memory base + * @n_channels: number of available channels + * @channels: array of DMAC channels + */ +struct usb_dmac { + struct dma_device engine; + struct device *dev; + void __iomem *iomem; + + unsigned int n_channels; + struct usb_dmac_chan *channels; +}; + +#define to_usb_dmac(d) container_of(d, struct usb_dmac, engine) + +/* ----------------------------------------------------------------------------- + * Registers + */ + +#define USB_DMAC_CHAN_OFFSET(i) (0x20 + 0x20 * (i)) + +#define USB_DMASWR 0x0008 +#define USB_DMASWR_SWR (1 << 0) +#define USB_DMAOR 0x0060 +#define USB_DMAOR_AE (1 << 1) +#define USB_DMAOR_DME (1 << 0) + +#define USB_DMASAR 0x0000 +#define USB_DMADAR 0x0004 +#define USB_DMATCR 0x0008 +#define USB_DMATCR_MASK 0x00ffffff +#define USB_DMACHCR 0x0014 +#define USB_DMACHCR_FTE (1 << 24) +#define USB_DMACHCR_NULLE (1 << 16) +#define USB_DMACHCR_NULL (1 << 12) +#define USB_DMACHCR_TS_8B ((0 << 7) | (0 << 6)) +#define USB_DMACHCR_TS_16B ((0 << 7) | (1 << 6)) +#define USB_DMACHCR_TS_32B ((1 << 7) | (0 << 6)) +#define USB_DMACHCR_IE (1 << 5) +#define USB_DMACHCR_SP (1 << 2) +#define USB_DMACHCR_TE (1 << 1) +#define USB_DMACHCR_DE (1 << 0) +#define USB_DMATEND 0x0018 + +/* Hardcode the xfer_shift to 5 (32bytes) */ +#define USB_DMAC_XFER_SHIFT 5 +#define USB_DMAC_XFER_SIZE (1 << USB_DMAC_XFER_SHIFT) +#define USB_DMAC_CHCR_TS USB_DMACHCR_TS_32B +#define USB_DMAC_SLAVE_BUSWIDTH DMA_SLAVE_BUSWIDTH_32_BYTES + +/* for descriptors */ +#define USB_DMAC_INITIAL_NR_DESC 16 +#define USB_DMAC_INITIAL_NR_SG 8 + +/* ----------------------------------------------------------------------------- + * Device access + */ + +static void usb_dmac_write(struct usb_dmac *dmac, u32 reg, u32 data) +{ + writel(data, dmac->iomem + reg); +} + +static u32 usb_dmac_read(struct usb_dmac *dmac, u32 reg) +{ + return readl(dmac->iomem + reg); +} + +static u32 usb_dmac_chan_read(struct usb_dmac_chan *chan, u32 reg) +{ + return readl(chan->iomem + reg); +} + +static void usb_dmac_chan_write(struct usb_dmac_chan *chan, u32 reg, u32 data) +{ + writel(data, chan->iomem + reg); +} + +/* ----------------------------------------------------------------------------- + * Initialization and configuration + */ + +static bool usb_dmac_chan_is_busy(struct usb_dmac_chan *chan) +{ + u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR); + + return (chcr & (USB_DMACHCR_DE | USB_DMACHCR_TE)) == USB_DMACHCR_DE; +} + +static u32 usb_dmac_calc_tend(u32 size) +{ + /* + * Please refer to the Figure "Example of Final Transaction Valid + * Data Transfer Enable (EDTEN) Setting" in the data sheet. + */ + return 0xffffffff << (32 - (size % USB_DMAC_XFER_SIZE ? : + USB_DMAC_XFER_SIZE)); +} + +/* This function is already held by vc.lock */ +static void usb_dmac_chan_start_sg(struct usb_dmac_chan *chan, + unsigned int index) +{ + struct usb_dmac_desc *desc = chan->desc; + struct usb_dmac_sg *sg = desc->sg + index; + dma_addr_t src_addr = 0, dst_addr = 0; + + WARN_ON_ONCE(usb_dmac_chan_is_busy(chan)); + + if (desc->direction == DMA_DEV_TO_MEM) + dst_addr = sg->mem_addr; + else + src_addr = sg->mem_addr; + + dev_dbg(chan->vc.chan.device->dev, + "chan%u: queue sg %p: %u@%pad -> %pad\n", + chan->index, sg, sg->size, &src_addr, &dst_addr); + + usb_dmac_chan_write(chan, USB_DMASAR, src_addr & 0xffffffff); + usb_dmac_chan_write(chan, USB_DMADAR, dst_addr & 0xffffffff); + usb_dmac_chan_write(chan, USB_DMATCR, + DIV_ROUND_UP(sg->size, USB_DMAC_XFER_SIZE)); + usb_dmac_chan_write(chan, USB_DMATEND, usb_dmac_calc_tend(sg->size)); + + usb_dmac_chan_write(chan, USB_DMACHCR, USB_DMAC_CHCR_TS | + USB_DMACHCR_NULLE | USB_DMACHCR_IE | USB_DMACHCR_DE); +} + +/* This function is already held by vc.lock */ +static void usb_dmac_chan_start_desc(struct usb_dmac_chan *chan) +{ + struct virt_dma_desc *vd; + + vd = vchan_next_desc(&chan->vc); + if (!vd) { + chan->desc = NULL; + return; + } + + /* + * Remove this request from vc->desc_issued. Otherwise, this driver + * will get the previous value from vchan_next_desc() after a transfer + * was completed. + */ + list_del(&vd->node); + + chan->desc = to_usb_dmac_desc(vd); + chan->desc->sg_index = 0; + usb_dmac_chan_start_sg(chan, 0); +} + +static int usb_dmac_init(struct usb_dmac *dmac) +{ + u16 dmaor; + + /* Clear all channels and enable the DMAC globally. */ + usb_dmac_write(dmac, USB_DMAOR, USB_DMAOR_DME); + + dmaor = usb_dmac_read(dmac, USB_DMAOR); + if ((dmaor & (USB_DMAOR_AE | USB_DMAOR_DME)) != USB_DMAOR_DME) { + dev_warn(dmac->dev, "DMAOR initialization failed.\n"); + return -EIO; + } + + return 0; +} + +/* ----------------------------------------------------------------------------- + * Descriptors allocation and free + */ +static int usb_dmac_desc_alloc(struct usb_dmac_chan *chan, unsigned int sg_len, + gfp_t gfp) +{ + struct usb_dmac_desc *desc; + unsigned long flags; + + desc = kzalloc(struct_size(desc, sg, sg_len), gfp); + if (!desc) + return -ENOMEM; + + desc->sg_allocated_len = sg_len; + INIT_LIST_HEAD(&desc->node); + + spin_lock_irqsave(&chan->vc.lock, flags); + list_add_tail(&desc->node, &chan->desc_freed); + spin_unlock_irqrestore(&chan->vc.lock, flags); + + return 0; +} + +static void usb_dmac_desc_free(struct usb_dmac_chan *chan) +{ + struct usb_dmac_desc *desc, *_desc; + LIST_HEAD(list); + + list_splice_init(&chan->desc_freed, &list); + list_splice_init(&chan->desc_got, &list); + + list_for_each_entry_safe(desc, _desc, &list, node) { + list_del(&desc->node); + kfree(desc); + } + chan->descs_allocated = 0; +} + +static struct usb_dmac_desc *usb_dmac_desc_get(struct usb_dmac_chan *chan, + unsigned int sg_len, gfp_t gfp) +{ + struct usb_dmac_desc *desc = NULL; + unsigned long flags; + + /* Get a freed descritpor */ + spin_lock_irqsave(&chan->vc.lock, flags); + list_for_each_entry(desc, &chan->desc_freed, node) { + if (sg_len <= desc->sg_allocated_len) { + list_move_tail(&desc->node, &chan->desc_got); + spin_unlock_irqrestore(&chan->vc.lock, flags); + return desc; + } + } + spin_unlock_irqrestore(&chan->vc.lock, flags); + + /* Allocate a new descriptor */ + if (!usb_dmac_desc_alloc(chan, sg_len, gfp)) { + /* If allocated the desc, it was added to tail of the list */ + spin_lock_irqsave(&chan->vc.lock, flags); + desc = list_last_entry(&chan->desc_freed, struct usb_dmac_desc, + node); + list_move_tail(&desc->node, &chan->desc_got); + spin_unlock_irqrestore(&chan->vc.lock, flags); + return desc; + } + + return NULL; +} + +static void usb_dmac_desc_put(struct usb_dmac_chan *chan, + struct usb_dmac_desc *desc) +{ + unsigned long flags; + + spin_lock_irqsave(&chan->vc.lock, flags); + list_move_tail(&desc->node, &chan->desc_freed); + spin_unlock_irqrestore(&chan->vc.lock, flags); +} + +/* ----------------------------------------------------------------------------- + * Stop and reset + */ + +static void usb_dmac_soft_reset(struct usb_dmac_chan *uchan) +{ + struct dma_chan *chan = &uchan->vc.chan; + struct usb_dmac *dmac = to_usb_dmac(chan->device); + int i; + + /* Don't issue soft reset if any one of channels is busy */ + for (i = 0; i < dmac->n_channels; ++i) { + if (usb_dmac_chan_is_busy(uchan)) + return; + } + + usb_dmac_write(dmac, USB_DMAOR, 0); + usb_dmac_write(dmac, USB_DMASWR, USB_DMASWR_SWR); + udelay(100); + usb_dmac_write(dmac, USB_DMASWR, 0); + usb_dmac_write(dmac, USB_DMAOR, 1); +} + +static void usb_dmac_chan_halt(struct usb_dmac_chan *chan) +{ + u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR); + + chcr &= ~(USB_DMACHCR_IE | USB_DMACHCR_TE | USB_DMACHCR_DE); + usb_dmac_chan_write(chan, USB_DMACHCR, chcr); + + usb_dmac_soft_reset(chan); +} + +static void usb_dmac_stop(struct usb_dmac *dmac) +{ + usb_dmac_write(dmac, USB_DMAOR, 0); +} + +/* ----------------------------------------------------------------------------- + * DMA engine operations + */ + +static int usb_dmac_alloc_chan_resources(struct dma_chan *chan) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + int ret; + + while (uchan->descs_allocated < USB_DMAC_INITIAL_NR_DESC) { + ret = usb_dmac_desc_alloc(uchan, USB_DMAC_INITIAL_NR_SG, + GFP_KERNEL); + if (ret < 0) { + usb_dmac_desc_free(uchan); + return ret; + } + uchan->descs_allocated++; + } + + return pm_runtime_get_sync(chan->device->dev); +} + +static void usb_dmac_free_chan_resources(struct dma_chan *chan) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + unsigned long flags; + + /* Protect against ISR */ + spin_lock_irqsave(&uchan->vc.lock, flags); + usb_dmac_chan_halt(uchan); + spin_unlock_irqrestore(&uchan->vc.lock, flags); + + usb_dmac_desc_free(uchan); + vchan_free_chan_resources(&uchan->vc); + + pm_runtime_put(chan->device->dev); +} + +static struct dma_async_tx_descriptor * +usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction dir, + unsigned long dma_flags, void *context) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + struct usb_dmac_desc *desc; + struct scatterlist *sg; + int i; + + if (!sg_len) { + dev_warn(chan->device->dev, + "%s: bad parameter: len=%d\n", __func__, sg_len); + return NULL; + } + + desc = usb_dmac_desc_get(uchan, sg_len, GFP_NOWAIT); + if (!desc) + return NULL; + + desc->direction = dir; + desc->sg_len = sg_len; + for_each_sg(sgl, sg, sg_len, i) { + desc->sg[i].mem_addr = sg_dma_address(sg); + desc->sg[i].size = sg_dma_len(sg); + } + + return vchan_tx_prep(&uchan->vc, &desc->vd, dma_flags); +} + +static int usb_dmac_chan_terminate_all(struct dma_chan *chan) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + struct usb_dmac_desc *desc, *_desc; + unsigned long flags; + LIST_HEAD(head); + LIST_HEAD(list); + + spin_lock_irqsave(&uchan->vc.lock, flags); + usb_dmac_chan_halt(uchan); + vchan_get_all_descriptors(&uchan->vc, &head); + if (uchan->desc) + uchan->desc = NULL; + list_splice_init(&uchan->desc_got, &list); + list_for_each_entry_safe(desc, _desc, &list, node) + list_move_tail(&desc->node, &uchan->desc_freed); + spin_unlock_irqrestore(&uchan->vc.lock, flags); + vchan_dma_desc_free_list(&uchan->vc, &head); + + return 0; +} + +static unsigned int usb_dmac_get_current_residue(struct usb_dmac_chan *chan, + struct usb_dmac_desc *desc, + unsigned int sg_index) +{ + struct usb_dmac_sg *sg = desc->sg + sg_index; + u32 mem_addr = sg->mem_addr & 0xffffffff; + unsigned int residue = sg->size; + + /* + * We cannot use USB_DMATCR to calculate residue because USB_DMATCR + * has unsuited value to calculate. + */ + if (desc->direction == DMA_DEV_TO_MEM) + residue -= usb_dmac_chan_read(chan, USB_DMADAR) - mem_addr; + else + residue -= usb_dmac_chan_read(chan, USB_DMASAR) - mem_addr; + + return residue; +} + +static u32 usb_dmac_chan_get_residue_if_complete(struct usb_dmac_chan *chan, + dma_cookie_t cookie) +{ + struct usb_dmac_desc *desc; + u32 residue = 0; + + list_for_each_entry_reverse(desc, &chan->desc_freed, node) { + if (desc->done_cookie == cookie) { + residue = desc->residue; + break; + } + } + + return residue; +} + +static u32 usb_dmac_chan_get_residue(struct usb_dmac_chan *chan, + dma_cookie_t cookie) +{ + u32 residue = 0; + struct virt_dma_desc *vd; + struct usb_dmac_desc *desc = chan->desc; + int i; + + if (!desc) { + vd = vchan_find_desc(&chan->vc, cookie); + if (!vd) + return 0; + desc = to_usb_dmac_desc(vd); + } + + /* Compute the size of all usb_dmac_sg still to be transferred */ + for (i = desc->sg_index + 1; i < desc->sg_len; i++) + residue += desc->sg[i].size; + + /* Add the residue for the current sg */ + residue += usb_dmac_get_current_residue(chan, desc, desc->sg_index); + + return residue; +} + +static enum dma_status usb_dmac_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + enum dma_status status; + unsigned int residue = 0; + unsigned long flags; + + status = dma_cookie_status(chan, cookie, txstate); + /* a client driver will get residue after DMA_COMPLETE */ + if (!txstate) + return status; + + spin_lock_irqsave(&uchan->vc.lock, flags); + if (status == DMA_COMPLETE) + residue = usb_dmac_chan_get_residue_if_complete(uchan, cookie); + else + residue = usb_dmac_chan_get_residue(uchan, cookie); + spin_unlock_irqrestore(&uchan->vc.lock, flags); + + dma_set_residue(txstate, residue); + + return status; +} + +static void usb_dmac_issue_pending(struct dma_chan *chan) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&uchan->vc.lock, flags); + if (vchan_issue_pending(&uchan->vc) && !uchan->desc) + usb_dmac_chan_start_desc(uchan); + spin_unlock_irqrestore(&uchan->vc.lock, flags); +} + +static void usb_dmac_virt_desc_free(struct virt_dma_desc *vd) +{ + struct usb_dmac_desc *desc = to_usb_dmac_desc(vd); + struct usb_dmac_chan *chan = to_usb_dmac_chan(vd->tx.chan); + + usb_dmac_desc_put(chan, desc); +} + +/* ----------------------------------------------------------------------------- + * IRQ handling + */ + +static void usb_dmac_isr_transfer_end(struct usb_dmac_chan *chan) +{ + struct usb_dmac_desc *desc = chan->desc; + + BUG_ON(!desc); + + if (++desc->sg_index < desc->sg_len) { + usb_dmac_chan_start_sg(chan, desc->sg_index); + } else { + desc->residue = usb_dmac_get_current_residue(chan, desc, + desc->sg_index - 1); + desc->done_cookie = desc->vd.tx.cookie; + desc->vd.tx_result.result = DMA_TRANS_NOERROR; + desc->vd.tx_result.residue = desc->residue; + vchan_cookie_complete(&desc->vd); + + /* Restart the next transfer if this driver has a next desc */ + usb_dmac_chan_start_desc(chan); + } +} + +static irqreturn_t usb_dmac_isr_channel(int irq, void *dev) +{ + struct usb_dmac_chan *chan = dev; + irqreturn_t ret = IRQ_NONE; + u32 mask = 0; + u32 chcr; + bool xfer_end = false; + + spin_lock(&chan->vc.lock); + + chcr = usb_dmac_chan_read(chan, USB_DMACHCR); + if (chcr & (USB_DMACHCR_TE | USB_DMACHCR_SP)) { + mask |= USB_DMACHCR_DE | USB_DMACHCR_TE | USB_DMACHCR_SP; + if (chcr & USB_DMACHCR_DE) + xfer_end = true; + ret |= IRQ_HANDLED; + } + if (chcr & USB_DMACHCR_NULL) { + /* An interruption of TE will happen after we set FTE */ + mask |= USB_DMACHCR_NULL; + chcr |= USB_DMACHCR_FTE; + ret |= IRQ_HANDLED; + } + if (mask) + usb_dmac_chan_write(chan, USB_DMACHCR, chcr & ~mask); + + if (xfer_end) + usb_dmac_isr_transfer_end(chan); + + spin_unlock(&chan->vc.lock); + + return ret; +} + +/* ----------------------------------------------------------------------------- + * OF xlate and channel filter + */ + +static bool usb_dmac_chan_filter(struct dma_chan *chan, void *arg) +{ + struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan); + struct of_phandle_args *dma_spec = arg; + + /* USB-DMAC should be used with fixed usb controller's FIFO */ + if (uchan->index != dma_spec->args[0]) + return false; + + return true; +} + +static struct dma_chan *usb_dmac_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_chan *chan; + dma_cap_mask_t mask; + + if (dma_spec->args_count != 1) + return NULL; + + /* Only slave DMA channels can be allocated via DT */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = __dma_request_channel(&mask, usb_dmac_chan_filter, dma_spec, + ofdma->of_node); + if (!chan) + return NULL; + + return chan; +} + +/* ----------------------------------------------------------------------------- + * Power management + */ + +#ifdef CONFIG_PM +static int usb_dmac_runtime_suspend(struct device *dev) +{ + struct usb_dmac *dmac = dev_get_drvdata(dev); + int i; + + for (i = 0; i < dmac->n_channels; ++i) { + if (!dmac->channels[i].iomem) + break; + usb_dmac_chan_halt(&dmac->channels[i]); + } + + return 0; +} + +static int usb_dmac_runtime_resume(struct device *dev) +{ + struct usb_dmac *dmac = dev_get_drvdata(dev); + + return usb_dmac_init(dmac); +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops usb_dmac_pm = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume, + NULL) +}; + +/* ----------------------------------------------------------------------------- + * Probe and remove + */ + +static int usb_dmac_chan_probe(struct usb_dmac *dmac, + struct usb_dmac_chan *uchan, + unsigned int index) +{ + struct platform_device *pdev = to_platform_device(dmac->dev); + char pdev_irqname[5]; + char *irqname; + int ret; + + uchan->index = index; + uchan->iomem = dmac->iomem + USB_DMAC_CHAN_OFFSET(index); + + /* Request the channel interrupt. */ + sprintf(pdev_irqname, "ch%u", index); + uchan->irq = platform_get_irq_byname(pdev, pdev_irqname); + if (uchan->irq < 0) + return -ENODEV; + + irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", + dev_name(dmac->dev), index); + if (!irqname) + return -ENOMEM; + + ret = devm_request_irq(dmac->dev, uchan->irq, usb_dmac_isr_channel, + IRQF_SHARED, irqname, uchan); + if (ret) { + dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", + uchan->irq, ret); + return ret; + } + + uchan->vc.desc_free = usb_dmac_virt_desc_free; + vchan_init(&uchan->vc, &dmac->engine); + INIT_LIST_HEAD(&uchan->desc_freed); + INIT_LIST_HEAD(&uchan->desc_got); + + return 0; +} + +static int usb_dmac_parse_of(struct device *dev, struct usb_dmac *dmac) +{ + struct device_node *np = dev->of_node; + int ret; + + ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); + if (ret < 0) { + dev_err(dev, "unable to read dma-channels property\n"); + return ret; + } + + if (dmac->n_channels <= 0 || dmac->n_channels >= 100) { + dev_err(dev, "invalid number of channels %u\n", + dmac->n_channels); + return -EINVAL; + } + + return 0; +} + +static int usb_dmac_probe(struct platform_device *pdev) +{ + const enum dma_slave_buswidth widths = USB_DMAC_SLAVE_BUSWIDTH; + struct dma_device *engine; + struct usb_dmac *dmac; + struct resource *mem; + unsigned int i; + int ret; + + dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); + if (!dmac) + return -ENOMEM; + + dmac->dev = &pdev->dev; + platform_set_drvdata(pdev, dmac); + + ret = usb_dmac_parse_of(&pdev->dev, dmac); + if (ret < 0) + return ret; + + dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, + sizeof(*dmac->channels), GFP_KERNEL); + if (!dmac->channels) + return -ENOMEM; + + /* Request resources. */ + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dmac->iomem = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(dmac->iomem)) + return PTR_ERR(dmac->iomem); + + /* Enable runtime PM and initialize the device. */ + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) { + dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); + goto error_pm; + } + + ret = usb_dmac_init(dmac); + + if (ret) { + dev_err(&pdev->dev, "failed to reset device\n"); + goto error; + } + + /* Initialize the channels. */ + INIT_LIST_HEAD(&dmac->engine.channels); + + for (i = 0; i < dmac->n_channels; ++i) { + ret = usb_dmac_chan_probe(dmac, &dmac->channels[i], i); + if (ret < 0) + goto error; + } + + /* Register the DMAC as a DMA provider for DT. */ + ret = of_dma_controller_register(pdev->dev.of_node, usb_dmac_of_xlate, + NULL); + if (ret < 0) + goto error; + + /* + * Register the DMA engine device. + * + * Default transfer size of 32 bytes requires 32-byte alignment. + */ + engine = &dmac->engine; + dma_cap_set(DMA_SLAVE, engine->cap_mask); + + engine->dev = &pdev->dev; + + engine->src_addr_widths = widths; + engine->dst_addr_widths = widths; + engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); + engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + + engine->device_alloc_chan_resources = usb_dmac_alloc_chan_resources; + engine->device_free_chan_resources = usb_dmac_free_chan_resources; + engine->device_prep_slave_sg = usb_dmac_prep_slave_sg; + engine->device_terminate_all = usb_dmac_chan_terminate_all; + engine->device_tx_status = usb_dmac_tx_status; + engine->device_issue_pending = usb_dmac_issue_pending; + + ret = dma_async_device_register(engine); + if (ret < 0) + goto error; + + pm_runtime_put(&pdev->dev); + return 0; + +error: + of_dma_controller_free(pdev->dev.of_node); +error_pm: + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); + return ret; +} + +static void usb_dmac_chan_remove(struct usb_dmac *dmac, + struct usb_dmac_chan *uchan) +{ + usb_dmac_chan_halt(uchan); + devm_free_irq(dmac->dev, uchan->irq, uchan); +} + +static int usb_dmac_remove(struct platform_device *pdev) +{ + struct usb_dmac *dmac = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < dmac->n_channels; ++i) + usb_dmac_chan_remove(dmac, &dmac->channels[i]); + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&dmac->engine); + + pm_runtime_disable(&pdev->dev); + + return 0; +} + +static void usb_dmac_shutdown(struct platform_device *pdev) +{ + struct usb_dmac *dmac = platform_get_drvdata(pdev); + + usb_dmac_stop(dmac); +} + +static const struct of_device_id usb_dmac_of_ids[] = { + { .compatible = "renesas,usb-dmac", }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, usb_dmac_of_ids); + +static struct platform_driver usb_dmac_driver = { + .driver = { + .pm = &usb_dmac_pm, + .name = "usb-dmac", + .of_match_table = usb_dmac_of_ids, + }, + .probe = usb_dmac_probe, + .remove = usb_dmac_remove, + .shutdown = usb_dmac_shutdown, +}; + +module_platform_driver(usb_dmac_driver); + +MODULE_DESCRIPTION("Renesas USB DMA Controller Driver"); +MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>"); +MODULE_LICENSE("GPL v2"); |