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Diffstat (limited to 'drivers/dma/at_hdmac.c')
| -rw-r--r-- | drivers/dma/at_hdmac.c | 2271 |
1 files changed, 2271 insertions, 0 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c new file mode 100644 index 0000000000..b2876f6747 --- /dev/null +++ b/drivers/dma/at_hdmac.c @@ -0,0 +1,2271 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems) + * + * Copyright (C) 2008 Atmel Corporation + * Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries + * + * This supports the Atmel AHB DMA Controller found in several Atmel SoCs. + * The only Atmel DMA Controller that is not covered by this driver is the one + * found on AT91SAM9263. + */ + +#include <dt-bindings/dma/at91.h> +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/dmaengine.h> +#include <linux/dmapool.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/overflow.h> +#include <linux/of_platform.h> +#include <linux/of_dma.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +/* + * Glossary + * -------- + * + * at_hdmac : Name of the ATmel AHB DMA Controller + * at_dma_ / atdma : ATmel DMA controller entity related + * atc_ / atchan : ATmel DMA Channel entity related + */ + +#define AT_DMA_MAX_NR_CHANNELS 8 + +/* Global Configuration Register */ +#define AT_DMA_GCFG 0x00 +#define AT_DMA_IF_BIGEND(i) BIT((i)) /* AHB-Lite Interface i in Big-endian mode */ +#define AT_DMA_ARB_CFG BIT(4) /* Arbiter mode. */ + +/* Controller Enable Register */ +#define AT_DMA_EN 0x04 +#define AT_DMA_ENABLE BIT(0) + +/* Software Single Request Register */ +#define AT_DMA_SREQ 0x08 +#define AT_DMA_SSREQ(x) BIT((x) << 1) /* Request a source single transfer on channel x */ +#define AT_DMA_DSREQ(x) BIT(1 + ((x) << 1)) /* Request a destination single transfer on channel x */ + +/* Software Chunk Transfer Request Register */ +#define AT_DMA_CREQ 0x0c +#define AT_DMA_SCREQ(x) BIT((x) << 1) /* Request a source chunk transfer on channel x */ +#define AT_DMA_DCREQ(x) BIT(1 + ((x) << 1)) /* Request a destination chunk transfer on channel x */ + +/* Software Last Transfer Flag Register */ +#define AT_DMA_LAST 0x10 +#define AT_DMA_SLAST(x) BIT((x) << 1) /* This src rq is last tx of buffer on channel x */ +#define AT_DMA_DLAST(x) BIT(1 + ((x) << 1)) /* This dst rq is last tx of buffer on channel x */ + +/* Request Synchronization Register */ +#define AT_DMA_SYNC 0x14 +#define AT_DMA_SYR(h) BIT((h)) /* Synchronize handshake line h */ + +/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */ +#define AT_DMA_EBCIER 0x18 /* Enable register */ +#define AT_DMA_EBCIDR 0x1c /* Disable register */ +#define AT_DMA_EBCIMR 0x20 /* Mask Register */ +#define AT_DMA_EBCISR 0x24 /* Status Register */ +#define AT_DMA_CBTC_OFFSET 8 +#define AT_DMA_ERR_OFFSET 16 +#define AT_DMA_BTC(x) BIT((x)) +#define AT_DMA_CBTC(x) BIT(AT_DMA_CBTC_OFFSET + (x)) +#define AT_DMA_ERR(x) BIT(AT_DMA_ERR_OFFSET + (x)) + +/* Channel Handler Enable Register */ +#define AT_DMA_CHER 0x28 +#define AT_DMA_ENA(x) BIT((x)) +#define AT_DMA_SUSP(x) BIT(8 + (x)) +#define AT_DMA_KEEP(x) BIT(24 + (x)) + +/* Channel Handler Disable Register */ +#define AT_DMA_CHDR 0x2c +#define AT_DMA_DIS(x) BIT(x) +#define AT_DMA_RES(x) BIT(8 + (x)) + +/* Channel Handler Status Register */ +#define AT_DMA_CHSR 0x30 +#define AT_DMA_EMPT(x) BIT(16 + (x)) +#define AT_DMA_STAL(x) BIT(24 + (x)) + +/* Channel registers base address */ +#define AT_DMA_CH_REGS_BASE 0x3c +#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */ + +/* Hardware register offset for each channel */ +#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */ +#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */ +#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */ +#define ATC_CTRLA_OFFSET 0x0c /* Control A Register */ +#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */ +#define ATC_CFG_OFFSET 0x14 /* Configuration Register */ +#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */ +#define ATC_DPIP_OFFSET 0x1c /* Dst PIP Configuration Register */ + + +/* Bitfield definitions */ + +/* Bitfields in DSCR */ +#define ATC_DSCR_IF GENMASK(1, 0) /* Dsc feched via AHB-Lite Interface */ + +/* Bitfields in CTRLA */ +#define ATC_BTSIZE_MAX GENMASK(15, 0) /* Maximum Buffer Transfer Size */ +#define ATC_BTSIZE GENMASK(15, 0) /* Buffer Transfer Size */ +#define ATC_SCSIZE GENMASK(18, 16) /* Source Chunk Transfer Size */ +#define ATC_DCSIZE GENMASK(22, 20) /* Destination Chunk Transfer Size */ +#define ATC_SRC_WIDTH GENMASK(25, 24) /* Source Single Transfer Size */ +#define ATC_DST_WIDTH GENMASK(29, 28) /* Destination Single Transfer Size */ +#define ATC_DONE BIT(31) /* Tx Done (only written back in descriptor) */ + +/* Bitfields in CTRLB */ +#define ATC_SIF GENMASK(1, 0) /* Src tx done via AHB-Lite Interface i */ +#define ATC_DIF GENMASK(5, 4) /* Dst tx done via AHB-Lite Interface i */ +#define AT_DMA_MEM_IF 0x0 /* interface 0 as memory interface */ +#define AT_DMA_PER_IF 0x1 /* interface 1 as peripheral interface */ +#define ATC_SRC_PIP BIT(8) /* Source Picture-in-Picture enabled */ +#define ATC_DST_PIP BIT(12) /* Destination Picture-in-Picture enabled */ +#define ATC_SRC_DSCR_DIS BIT(16) /* Src Descriptor fetch disable */ +#define ATC_DST_DSCR_DIS BIT(20) /* Dst Descriptor fetch disable */ +#define ATC_FC GENMASK(23, 21) /* Choose Flow Controller */ +#define ATC_FC_MEM2MEM 0x0 /* Mem-to-Mem (DMA) */ +#define ATC_FC_MEM2PER 0x1 /* Mem-to-Periph (DMA) */ +#define ATC_FC_PER2MEM 0x2 /* Periph-to-Mem (DMA) */ +#define ATC_FC_PER2PER 0x3 /* Periph-to-Periph (DMA) */ +#define ATC_FC_PER2MEM_PER 0x4 /* Periph-to-Mem (Peripheral) */ +#define ATC_FC_MEM2PER_PER 0x5 /* Mem-to-Periph (Peripheral) */ +#define ATC_FC_PER2PER_SRCPER 0x6 /* Periph-to-Periph (Src Peripheral) */ +#define ATC_FC_PER2PER_DSTPER 0x7 /* Periph-to-Periph (Dst Peripheral) */ +#define ATC_SRC_ADDR_MODE GENMASK(25, 24) +#define ATC_SRC_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ +#define ATC_SRC_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ +#define ATC_SRC_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ +#define ATC_DST_ADDR_MODE GENMASK(29, 28) +#define ATC_DST_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ +#define ATC_DST_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ +#define ATC_DST_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ +#define ATC_IEN BIT(30) /* BTC interrupt enable (active low) */ +#define ATC_AUTO BIT(31) /* Auto multiple buffer tx enable */ + +/* Bitfields in CFG */ +#define ATC_SRC_PER GENMASK(3, 0) /* Channel src rq associated with periph handshaking ifc h */ +#define ATC_DST_PER GENMASK(7, 4) /* Channel dst rq associated with periph handshaking ifc h */ +#define ATC_SRC_REP BIT(8) /* Source Replay Mod */ +#define ATC_SRC_H2SEL BIT(9) /* Source Handshaking Mod */ +#define ATC_SRC_PER_MSB GENMASK(11, 10) /* Channel src rq (most significant bits) */ +#define ATC_DST_REP BIT(12) /* Destination Replay Mod */ +#define ATC_DST_H2SEL BIT(13) /* Destination Handshaking Mod */ +#define ATC_DST_PER_MSB GENMASK(15, 14) /* Channel dst rq (most significant bits) */ +#define ATC_SOD BIT(16) /* Stop On Done */ +#define ATC_LOCK_IF BIT(20) /* Interface Lock */ +#define ATC_LOCK_B BIT(21) /* AHB Bus Lock */ +#define ATC_LOCK_IF_L BIT(22) /* Master Interface Arbiter Lock */ +#define ATC_AHB_PROT GENMASK(26, 24) /* AHB Protection */ +#define ATC_FIFOCFG GENMASK(29, 28) /* FIFO Request Configuration */ +#define ATC_FIFOCFG_LARGESTBURST 0x0 +#define ATC_FIFOCFG_HALFFIFO 0x1 +#define ATC_FIFOCFG_ENOUGHSPACE 0x2 + +/* Bitfields in SPIP */ +#define ATC_SPIP_HOLE GENMASK(15, 0) +#define ATC_SPIP_BOUNDARY GENMASK(25, 16) + +/* Bitfields in DPIP */ +#define ATC_DPIP_HOLE GENMASK(15, 0) +#define ATC_DPIP_BOUNDARY GENMASK(25, 16) + +#define ATC_PER_MSB GENMASK(5, 4) /* Extract MSBs of a handshaking identifier */ +#define ATC_SRC_PER_ID(id) \ + ({ typeof(id) _id = (id); \ + FIELD_PREP(ATC_SRC_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ + FIELD_PREP(ATC_SRC_PER, _id); }) +#define ATC_DST_PER_ID(id) \ + ({ typeof(id) _id = (id); \ + FIELD_PREP(ATC_DST_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ + FIELD_PREP(ATC_DST_PER, _id); }) + + + +/*-- descriptors -----------------------------------------------------*/ + +/* LLI == Linked List Item; aka DMA buffer descriptor */ +struct at_lli { + /* values that are not changed by hardware */ + u32 saddr; + u32 daddr; + /* value that may get written back: */ + u32 ctrla; + /* more values that are not changed by hardware */ + u32 ctrlb; + u32 dscr; /* chain to next lli */ +}; + +/** + * struct atdma_sg - atdma scatter gather entry + * @len: length of the current Linked List Item. + * @lli: linked list item that is passed to the DMA controller + * @lli_phys: physical address of the LLI. + */ +struct atdma_sg { + unsigned int len; + struct at_lli *lli; + dma_addr_t lli_phys; +}; + +/** + * struct at_desc - software descriptor + * @vd: pointer to the virtual dma descriptor. + * @atchan: pointer to the atmel dma channel. + * @total_len: total transaction byte count + * @sg_len: number of sg entries. + * @sg: array of sgs. + */ +struct at_desc { + struct virt_dma_desc vd; + struct at_dma_chan *atchan; + size_t total_len; + unsigned int sglen; + /* Interleaved data */ + size_t boundary; + size_t dst_hole; + size_t src_hole; + + /* Memset temporary buffer */ + bool memset_buffer; + dma_addr_t memset_paddr; + int *memset_vaddr; + struct atdma_sg sg[]; +}; + +/*-- Channels --------------------------------------------------------*/ + +/** + * atc_status - information bits stored in channel status flag + * + * Manipulated with atomic operations. + */ +enum atc_status { + ATC_IS_PAUSED = 1, + ATC_IS_CYCLIC = 24, +}; + +/** + * struct at_dma_chan - internal representation of an Atmel HDMAC channel + * @vc: virtual dma channel entry. + * @atdma: pointer to the driver data. + * @ch_regs: memory mapped register base + * @mask: channel index in a mask + * @per_if: peripheral interface + * @mem_if: memory interface + * @status: transmit status information from irq/prep* functions + * to tasklet (use atomic operations) + * @save_cfg: configuration register that is saved on suspend/resume cycle + * @save_dscr: for cyclic operations, preserve next descriptor address in + * the cyclic list on suspend/resume cycle + * @dma_sconfig: configuration for slave transfers, passed via + * .device_config + * @desc: pointer to the atmel dma descriptor. + */ +struct at_dma_chan { + struct virt_dma_chan vc; + struct at_dma *atdma; + void __iomem *ch_regs; + u8 mask; + u8 per_if; + u8 mem_if; + unsigned long status; + u32 save_cfg; + u32 save_dscr; + struct dma_slave_config dma_sconfig; + bool cyclic; + struct at_desc *desc; +}; + +#define channel_readl(atchan, name) \ + __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET) + +#define channel_writel(atchan, name, val) \ + __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET) + +/* + * Fix sconfig's burst size according to at_hdmac. We need to convert them as: + * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7. + * + * This can be done by finding most significant bit set. + */ +static inline void convert_burst(u32 *maxburst) +{ + if (*maxburst > 1) + *maxburst = fls(*maxburst) - 2; + else + *maxburst = 0; +} + +/* + * Fix sconfig's bus width according to at_hdmac. + * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2. + */ +static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width) +{ + switch (addr_width) { + case DMA_SLAVE_BUSWIDTH_2_BYTES: + return 1; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + return 2; + default: + /* For 1 byte width or fallback */ + return 0; + } +} + +/*-- Controller ------------------------------------------------------*/ + +/** + * struct at_dma - internal representation of an Atmel HDMA Controller + * @dma_device: dmaengine dma_device object members + * @atdma_devtype: identifier of DMA controller compatibility + * @ch_regs: memory mapped register base + * @clk: dma controller clock + * @save_imr: interrupt mask register that is saved on suspend/resume cycle + * @all_chan_mask: all channels availlable in a mask + * @lli_pool: hw lli table + * @chan: channels table to store at_dma_chan structures + */ +struct at_dma { + struct dma_device dma_device; + void __iomem *regs; + struct clk *clk; + u32 save_imr; + + u8 all_chan_mask; + + struct dma_pool *lli_pool; + struct dma_pool *memset_pool; + /* AT THE END channels table */ + struct at_dma_chan chan[]; +}; + +#define dma_readl(atdma, name) \ + __raw_readl((atdma)->regs + AT_DMA_##name) +#define dma_writel(atdma, name, val) \ + __raw_writel((val), (atdma)->regs + AT_DMA_##name) + +static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t) +{ + return container_of(t, struct at_desc, vd.tx); +} + +static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan) +{ + return container_of(chan, struct at_dma_chan, vc.chan); +} + +static inline struct at_dma *to_at_dma(struct dma_device *ddev) +{ + return container_of(ddev, struct at_dma, dma_device); +} + + +/*-- Helper functions ------------------------------------------------*/ + +static struct device *chan2dev(struct dma_chan *chan) +{ + return &chan->dev->device; +} + +#if defined(VERBOSE_DEBUG) +static void vdbg_dump_regs(struct at_dma_chan *atchan) +{ + struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); + + dev_err(chan2dev(&atchan->vc.chan), + " channel %d : imr = 0x%x, chsr = 0x%x\n", + atchan->vc.chan.chan_id, + dma_readl(atdma, EBCIMR), + dma_readl(atdma, CHSR)); + + dev_err(chan2dev(&atchan->vc.chan), + " channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n", + channel_readl(atchan, SADDR), + channel_readl(atchan, DADDR), + channel_readl(atchan, CTRLA), + channel_readl(atchan, CTRLB), + channel_readl(atchan, CFG), + channel_readl(atchan, DSCR)); +} +#else +static void vdbg_dump_regs(struct at_dma_chan *atchan) {} +#endif + +static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli) +{ + dev_crit(chan2dev(&atchan->vc.chan), + "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n", + &lli->saddr, &lli->daddr, + lli->ctrla, lli->ctrlb, &lli->dscr); +} + + +static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on) +{ + u32 ebci; + + /* enable interrupts on buffer transfer completion & error */ + ebci = AT_DMA_BTC(chan_id) + | AT_DMA_ERR(chan_id); + if (on) + dma_writel(atdma, EBCIER, ebci); + else + dma_writel(atdma, EBCIDR, ebci); +} + +static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id) +{ + atc_setup_irq(atdma, chan_id, 1); +} + +static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id) +{ + atc_setup_irq(atdma, chan_id, 0); +} + + +/** + * atc_chan_is_enabled - test if given channel is enabled + * @atchan: channel we want to test status + */ +static inline int atc_chan_is_enabled(struct at_dma_chan *atchan) +{ + struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); + + return !!(dma_readl(atdma, CHSR) & atchan->mask); +} + +/** + * atc_chan_is_paused - test channel pause/resume status + * @atchan: channel we want to test status + */ +static inline int atc_chan_is_paused(struct at_dma_chan *atchan) +{ + return test_bit(ATC_IS_PAUSED, &atchan->status); +} + +/** + * atc_chan_is_cyclic - test if given channel has cyclic property set + * @atchan: channel we want to test status + */ +static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan) +{ + return test_bit(ATC_IS_CYCLIC, &atchan->status); +} + +/** + * set_lli_eol - set end-of-link to descriptor so it will end transfer + * @desc: descriptor, signle or at the end of a chain, to end chain on + * @i: index of the atmel scatter gather entry that is at the end of the chain. + */ +static void set_lli_eol(struct at_desc *desc, unsigned int i) +{ + u32 ctrlb = desc->sg[i].lli->ctrlb; + + ctrlb &= ~ATC_IEN; + ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS; + + desc->sg[i].lli->ctrlb = ctrlb; + desc->sg[i].lli->dscr = 0; +} + +#define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO) +#define ATC_DEFAULT_CTRLB (FIELD_PREP(ATC_SIF, AT_DMA_MEM_IF) | \ + FIELD_PREP(ATC_DIF, AT_DMA_MEM_IF)) +#define ATC_DMA_BUSWIDTHS\ + (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\ + BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\ + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\ + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) + +#define ATC_MAX_DSCR_TRIALS 10 + +/* + * Initial number of descriptors to allocate for each channel. This could + * be increased during dma usage. + */ +static unsigned int init_nr_desc_per_channel = 64; +module_param(init_nr_desc_per_channel, uint, 0644); +MODULE_PARM_DESC(init_nr_desc_per_channel, + "initial descriptors per channel (default: 64)"); + +/** + * struct at_dma_platform_data - Controller configuration parameters + * @nr_channels: Number of channels supported by hardware (max 8) + * @cap_mask: dma_capability flags supported by the platform + */ +struct at_dma_platform_data { + unsigned int nr_channels; + dma_cap_mask_t cap_mask; +}; + +/** + * struct at_dma_slave - Controller-specific information about a slave + * @dma_dev: required DMA master device + * @cfg: Platform-specific initializer for the CFG register + */ +struct at_dma_slave { + struct device *dma_dev; + u32 cfg; +}; + +static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst, + size_t len) +{ + unsigned int width; + + if (!((src | dst | len) & 3)) + width = 2; + else if (!((src | dst | len) & 1)) + width = 1; + else + width = 0; + + return width; +} + +static void atdma_lli_chain(struct at_desc *desc, unsigned int i) +{ + struct atdma_sg *atdma_sg = &desc->sg[i]; + + if (i) + desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys; +} + +/** + * atc_dostart - starts the DMA engine for real + * @atchan: the channel we want to start + */ +static void atc_dostart(struct at_dma_chan *atchan) +{ + struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc); + struct at_desc *desc; + + if (!vd) { + atchan->desc = NULL; + return; + } + + vdbg_dump_regs(atchan); + + list_del(&vd->node); + atchan->desc = desc = to_atdma_desc(&vd->tx); + + channel_writel(atchan, SADDR, 0); + channel_writel(atchan, DADDR, 0); + channel_writel(atchan, CTRLA, 0); + channel_writel(atchan, CTRLB, 0); + channel_writel(atchan, DSCR, desc->sg[0].lli_phys); + channel_writel(atchan, SPIP, + FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) | + FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary)); + channel_writel(atchan, DPIP, + FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) | + FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary)); + + /* Don't allow CPU to reorder channel enable. */ + wmb(); + dma_writel(atchan->atdma, CHER, atchan->mask); + + vdbg_dump_regs(atchan); +} + +static void atdma_desc_free(struct virt_dma_desc *vd) +{ + struct at_dma *atdma = to_at_dma(vd->tx.chan->device); + struct at_desc *desc = to_atdma_desc(&vd->tx); + unsigned int i; + + for (i = 0; i < desc->sglen; i++) { + if (desc->sg[i].lli) + dma_pool_free(atdma->lli_pool, desc->sg[i].lli, + desc->sg[i].lli_phys); + } + + /* If the transfer was a memset, free our temporary buffer */ + if (desc->memset_buffer) { + dma_pool_free(atdma->memset_pool, desc->memset_vaddr, + desc->memset_paddr); + desc->memset_buffer = false; + } + + kfree(desc); +} + +/** + * atc_calc_bytes_left - calculates the number of bytes left according to the + * value read from CTRLA. + * + * @current_len: the number of bytes left before reading CTRLA + * @ctrla: the value of CTRLA + */ +static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla) +{ + u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla); + u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla); + + /* + * According to the datasheet, when reading the Control A Register + * (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the + * number of transfers completed on the Source Interface. + * So btsize is always a number of source width transfers. + */ + return current_len - (btsize << src_width); +} + +/** + * atc_get_llis_residue - Get residue for a hardware linked list transfer + * + * Calculate the residue by removing the length of the Linked List Item (LLI) + * already transferred from the total length. To get the current LLI we can use + * the value of the channel's DSCR register and compare it against the DSCR + * value of each LLI. + * + * The CTRLA register provides us with the amount of data already read from the + * source for the LLI. So we can compute a more accurate residue by also + * removing the number of bytes corresponding to this amount of data. + * + * However, the DSCR and CTRLA registers cannot be read both atomically. Hence a + * race condition may occur: the first read register may refer to one LLI + * whereas the second read may refer to a later LLI in the list because of the + * DMA transfer progression inbetween the two reads. + * + * One solution could have been to pause the DMA transfer, read the DSCR and + * CTRLA then resume the DMA transfer. Nonetheless, this approach presents some + * drawbacks: + * - If the DMA transfer is paused, RX overruns or TX underruns are more likey + * to occur depending on the system latency. Taking the USART driver as an + * example, it uses a cyclic DMA transfer to read data from the Receive + * Holding Register (RHR) to avoid RX overruns since the RHR is not protected + * by any FIFO on most Atmel SoCs. So pausing the DMA transfer to compute the + * residue would break the USART driver design. + * - The atc_pause() function masks interrupts but we'd rather avoid to do so + * for system latency purpose. + * + * Then we'd rather use another solution: the DSCR is read a first time, the + * CTRLA is read in turn, next the DSCR is read a second time. If the two + * consecutive read values of the DSCR are the same then we assume both refers + * to the very same LLI as well as the CTRLA value read inbetween does. For + * cyclic tranfers, the assumption is that a full loop is "not so fast". If the + * two DSCR values are different, we read again the CTRLA then the DSCR till two + * consecutive read values from DSCR are equal or till the maximum trials is + * reach. This algorithm is very unlikely not to find a stable value for DSCR. + * @atchan: pointer to an atmel hdmac channel. + * @desc: pointer to the descriptor for which the residue is calculated. + * @residue: residue to be set to dma_tx_state. + * Returns 0 on success, -errno otherwise. + */ +static int atc_get_llis_residue(struct at_dma_chan *atchan, + struct at_desc *desc, u32 *residue) +{ + u32 len, ctrla, dscr; + unsigned int i; + + len = desc->total_len; + dscr = channel_readl(atchan, DSCR); + rmb(); /* ensure DSCR is read before CTRLA */ + ctrla = channel_readl(atchan, CTRLA); + for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) { + u32 new_dscr; + + rmb(); /* ensure DSCR is read after CTRLA */ + new_dscr = channel_readl(atchan, DSCR); + + /* + * If the DSCR register value has not changed inside the DMA + * controller since the previous read, we assume that both the + * dscr and ctrla values refers to the very same descriptor. + */ + if (likely(new_dscr == dscr)) + break; + + /* + * DSCR has changed inside the DMA controller, so the previouly + * read value of CTRLA may refer to an already processed + * descriptor hence could be outdated. We need to update ctrla + * to match the current descriptor. + */ + dscr = new_dscr; + rmb(); /* ensure DSCR is read before CTRLA */ + ctrla = channel_readl(atchan, CTRLA); + } + if (unlikely(i == ATC_MAX_DSCR_TRIALS)) + return -ETIMEDOUT; + + /* For the first descriptor we can be more accurate. */ + if (desc->sg[0].lli->dscr == dscr) { + *residue = atc_calc_bytes_left(len, ctrla); + return 0; + } + len -= desc->sg[0].len; + + for (i = 1; i < desc->sglen; i++) { + if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr) + break; + len -= desc->sg[i].len; + } + + /* + * For the current LLI in the chain we can calculate the remaining bytes + * using the channel's CTRLA register. + */ + *residue = atc_calc_bytes_left(len, ctrla); + return 0; + +} + +/** + * atc_get_residue - get the number of bytes residue for a cookie. + * The residue is passed by address and updated on success. + * @chan: DMA channel + * @cookie: transaction identifier to check status of + * @residue: residue to be updated. + * Return 0 on success, -errono otherwise. + */ +static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie, + u32 *residue) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct virt_dma_desc *vd; + struct at_desc *desc = NULL; + u32 len, ctrla; + + vd = vchan_find_desc(&atchan->vc, cookie); + if (vd) + desc = to_atdma_desc(&vd->tx); + else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie) + desc = atchan->desc; + + if (!desc) + return -EINVAL; + + if (desc->sg[0].lli->dscr) + /* hardware linked list transfer */ + return atc_get_llis_residue(atchan, desc, residue); + + /* single transfer */ + len = desc->total_len; + ctrla = channel_readl(atchan, CTRLA); + *residue = atc_calc_bytes_left(len, ctrla); + return 0; +} + +/** + * atc_handle_error - handle errors reported by DMA controller + * @atchan: channel where error occurs. + * @i: channel index + */ +static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i) +{ + struct at_desc *desc = atchan->desc; + + /* Disable channel on AHB error */ + dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask); + + /* + * KERN_CRITICAL may seem harsh, but since this only happens + * when someone submits a bad physical address in a + * descriptor, we should consider ourselves lucky that the + * controller flagged an error instead of scribbling over + * random memory locations. + */ + dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n"); + dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n", + desc->vd.tx.cookie); + for (i = 0; i < desc->sglen; i++) + atc_dump_lli(atchan, desc->sg[i].lli); +} + +static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending, + unsigned int i) +{ + struct at_desc *desc; + + spin_lock(&atchan->vc.lock); + desc = atchan->desc; + + if (desc) { + if (pending & AT_DMA_ERR(i)) { + atc_handle_error(atchan, i); + /* Pretend the descriptor completed successfully */ + } + + if (atc_chan_is_cyclic(atchan)) { + vchan_cyclic_callback(&desc->vd); + } else { + vchan_cookie_complete(&desc->vd); + atchan->desc = NULL; + if (!(atc_chan_is_enabled(atchan))) + atc_dostart(atchan); + } + } + spin_unlock(&atchan->vc.lock); +} + +static irqreturn_t at_dma_interrupt(int irq, void *dev_id) +{ + struct at_dma *atdma = dev_id; + struct at_dma_chan *atchan; + int i; + u32 status, pending, imr; + int ret = IRQ_NONE; + + do { + imr = dma_readl(atdma, EBCIMR); + status = dma_readl(atdma, EBCISR); + pending = status & imr; + + if (!pending) + break; + + dev_vdbg(atdma->dma_device.dev, + "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n", + status, imr, pending); + + for (i = 0; i < atdma->dma_device.chancnt; i++) { + atchan = &atdma->chan[i]; + if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i)))) + continue; + atdma_handle_chan_done(atchan, pending, i); + ret = IRQ_HANDLED; + } + + } while (pending); + + return ret; +} + +/*-- DMA Engine API --------------------------------------------------*/ +/** + * atc_prep_dma_interleaved - prepare memory to memory interleaved operation + * @chan: the channel to prepare operation on + * @xt: Interleaved transfer template + * @flags: tx descriptor status flags + */ +static struct dma_async_tx_descriptor * +atc_prep_dma_interleaved(struct dma_chan *chan, + struct dma_interleaved_template *xt, + unsigned long flags) +{ + struct at_dma *atdma = to_at_dma(chan->device); + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct data_chunk *first; + struct atdma_sg *atdma_sg; + struct at_desc *desc; + struct at_lli *lli; + size_t xfer_count; + unsigned int dwidth; + u32 ctrla; + u32 ctrlb; + size_t len = 0; + int i; + + if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) + return NULL; + + first = xt->sgl; + + dev_info(chan2dev(chan), + "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", + __func__, &xt->src_start, &xt->dst_start, xt->numf, + xt->frame_size, flags); + + /* + * The controller can only "skip" X bytes every Y bytes, so we + * need to make sure we are given a template that fit that + * description, ie a template with chunks that always have the + * same size, with the same ICGs. + */ + for (i = 0; i < xt->frame_size; i++) { + struct data_chunk *chunk = xt->sgl + i; + + if ((chunk->size != xt->sgl->size) || + (dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) || + (dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) { + dev_err(chan2dev(chan), + "%s: the controller can transfer only identical chunks\n", + __func__); + return NULL; + } + + len += chunk->size; + } + + dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len); + + xfer_count = len >> dwidth; + if (xfer_count > ATC_BTSIZE_MAX) { + dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); + return NULL; + } + + ctrla = FIELD_PREP(ATC_SRC_WIDTH, dwidth) | + FIELD_PREP(ATC_DST_WIDTH, dwidth); + + ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | + FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | + FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | + ATC_SRC_PIP | ATC_DST_PIP | + FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); + + desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); + if (!desc) + return NULL; + desc->sglen = 1; + + atdma_sg = desc->sg; + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) { + kfree(desc); + return NULL; + } + lli = atdma_sg->lli; + + lli->saddr = xt->src_start; + lli->daddr = xt->dst_start; + lli->ctrla = ctrla | xfer_count; + lli->ctrlb = ctrlb; + + desc->boundary = first->size >> dwidth; + desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1; + desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1; + + atdma_sg->len = len; + desc->total_len = len; + + set_lli_eol(desc, 0); + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); +} + +/** + * atc_prep_dma_memcpy - prepare a memcpy operation + * @chan: the channel to prepare operation on + * @dest: operation virtual destination address + * @src: operation virtual source address + * @len: operation length + * @flags: tx descriptor status flags + */ +static struct dma_async_tx_descriptor * +atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct at_dma *atdma = to_at_dma(chan->device); + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_desc *desc = NULL; + size_t xfer_count; + size_t offset; + size_t sg_len; + unsigned int src_width; + unsigned int dst_width; + unsigned int i; + u32 ctrla; + u32 ctrlb; + + dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n", + &dest, &src, len, flags); + + if (unlikely(!len)) { + dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n"); + return NULL; + } + + sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX); + desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); + if (!desc) + return NULL; + desc->sglen = sg_len; + + ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | + FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | + FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | + FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); + + /* + * We can be a lot more clever here, but this should take care + * of the most common optimization. + */ + src_width = dst_width = atc_get_xfer_width(src, dest, len); + + ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) | + FIELD_PREP(ATC_DST_WIDTH, dst_width); + + for (offset = 0, i = 0; offset < len; + offset += xfer_count << src_width, i++) { + struct atdma_sg *atdma_sg = &desc->sg[i]; + struct at_lli *lli; + + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) + goto err_desc_get; + lli = atdma_sg->lli; + + xfer_count = min_t(size_t, (len - offset) >> src_width, + ATC_BTSIZE_MAX); + + lli->saddr = src + offset; + lli->daddr = dest + offset; + lli->ctrla = ctrla | xfer_count; + lli->ctrlb = ctrlb; + + desc->sg[i].len = xfer_count << src_width; + + atdma_lli_chain(desc, i); + } + + desc->total_len = len; + + /* set end-of-link to the last link descriptor of list*/ + set_lli_eol(desc, i - 1); + + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); + +err_desc_get: + atdma_desc_free(&desc->vd); + return NULL; +} + +static int atdma_create_memset_lli(struct dma_chan *chan, + struct atdma_sg *atdma_sg, + dma_addr_t psrc, dma_addr_t pdst, size_t len) +{ + struct at_dma *atdma = to_at_dma(chan->device); + struct at_lli *lli; + size_t xfer_count; + u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2); + u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | + FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) | + FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | + FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); + + xfer_count = len >> 2; + if (xfer_count > ATC_BTSIZE_MAX) { + dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); + return -EINVAL; + } + + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) + return -ENOMEM; + lli = atdma_sg->lli; + + lli->saddr = psrc; + lli->daddr = pdst; + lli->ctrla = ctrla | xfer_count; + lli->ctrlb = ctrlb; + + atdma_sg->len = len; + + return 0; +} + +/** + * atc_prep_dma_memset - prepare a memcpy operation + * @chan: the channel to prepare operation on + * @dest: operation virtual destination address + * @value: value to set memory buffer to + * @len: operation length + * @flags: tx descriptor status flags + */ +static struct dma_async_tx_descriptor * +atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, + size_t len, unsigned long flags) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + struct at_desc *desc; + void __iomem *vaddr; + dma_addr_t paddr; + char fill_pattern; + int ret; + + dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__, + &dest, value, len, flags); + + if (unlikely(!len)) { + dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); + return NULL; + } + + if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { + dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n", + __func__); + return NULL; + } + + vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); + if (!vaddr) { + dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", + __func__); + return NULL; + } + + /* Only the first byte of value is to be used according to dmaengine */ + fill_pattern = (char)value; + + *(u32*)vaddr = (fill_pattern << 24) | + (fill_pattern << 16) | + (fill_pattern << 8) | + fill_pattern; + + desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); + if (!desc) + goto err_free_buffer; + desc->sglen = 1; + + ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len); + if (ret) + goto err_free_desc; + + desc->memset_paddr = paddr; + desc->memset_vaddr = vaddr; + desc->memset_buffer = true; + + desc->total_len = len; + + /* set end-of-link on the descriptor */ + set_lli_eol(desc, 0); + + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); + +err_free_desc: + kfree(desc); +err_free_buffer: + dma_pool_free(atdma->memset_pool, vaddr, paddr); + return NULL; +} + +static struct dma_async_tx_descriptor * +atc_prep_dma_memset_sg(struct dma_chan *chan, + struct scatterlist *sgl, + unsigned int sg_len, int value, + unsigned long flags) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + struct at_desc *desc; + struct scatterlist *sg; + void __iomem *vaddr; + dma_addr_t paddr; + size_t total_len = 0; + int i; + int ret; + + dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__, + value, sg_len, flags); + + if (unlikely(!sgl || !sg_len)) { + dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n", + __func__); + return NULL; + } + + vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); + if (!vaddr) { + dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", + __func__); + return NULL; + } + *(u32*)vaddr = value; + + desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); + if (!desc) + goto err_free_dma_buf; + desc->sglen = sg_len; + + for_each_sg(sgl, sg, sg_len, i) { + dma_addr_t dest = sg_dma_address(sg); + size_t len = sg_dma_len(sg); + + dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n", + __func__, &dest, len); + + if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { + dev_err(chan2dev(chan), "%s: buffer is not aligned\n", + __func__); + goto err_free_desc; + } + + ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest, + len); + if (ret) + goto err_free_desc; + + atdma_lli_chain(desc, i); + total_len += len; + } + + desc->memset_paddr = paddr; + desc->memset_vaddr = vaddr; + desc->memset_buffer = true; + + desc->total_len = total_len; + + /* set end-of-link on the descriptor */ + set_lli_eol(desc, i - 1); + + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); + +err_free_desc: + atdma_desc_free(&desc->vd); +err_free_dma_buf: + dma_pool_free(atdma->memset_pool, vaddr, paddr); + return NULL; +} + +/** + * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction + * @chan: DMA channel + * @sgl: scatterlist to transfer to/from + * @sg_len: number of entries in @scatterlist + * @direction: DMA direction + * @flags: tx descriptor status flags + * @context: transaction context (ignored) + */ +static struct dma_async_tx_descriptor * +atc_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 at_dma *atdma = to_at_dma(chan->device); + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma_slave *atslave = chan->private; + struct dma_slave_config *sconfig = &atchan->dma_sconfig; + struct at_desc *desc; + u32 ctrla; + u32 ctrlb; + dma_addr_t reg; + unsigned int reg_width; + unsigned int mem_width; + unsigned int i; + struct scatterlist *sg; + size_t total_len = 0; + + dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n", + sg_len, + direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", + flags); + + if (unlikely(!atslave || !sg_len)) { + dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n"); + return NULL; + } + + desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); + if (!desc) + return NULL; + desc->sglen = sg_len; + + ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | + FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst); + ctrlb = ATC_IEN; + + switch (direction) { + case DMA_MEM_TO_DEV: + reg_width = convert_buswidth(sconfig->dst_addr_width); + ctrla |= FIELD_PREP(ATC_DST_WIDTH, reg_width); + ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, + ATC_DST_ADDR_MODE_FIXED) | + FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | + FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | + FIELD_PREP(ATC_SIF, atchan->mem_if) | + FIELD_PREP(ATC_DIF, atchan->per_if); + reg = sconfig->dst_addr; + for_each_sg(sgl, sg, sg_len, i) { + struct atdma_sg *atdma_sg = &desc->sg[i]; + struct at_lli *lli; + u32 len; + u32 mem; + + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, + GFP_NOWAIT, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) + goto err_desc_get; + lli = atdma_sg->lli; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + if (unlikely(!len)) { + dev_dbg(chan2dev(chan), + "prep_slave_sg: sg(%d) data length is zero\n", i); + goto err; + } + mem_width = 2; + if (unlikely(mem & 3 || len & 3)) + mem_width = 0; + + lli->saddr = mem; + lli->daddr = reg; + lli->ctrla = ctrla | + FIELD_PREP(ATC_SRC_WIDTH, mem_width) | + len >> mem_width; + lli->ctrlb = ctrlb; + + atdma_sg->len = len; + total_len += len; + + desc->sg[i].len = len; + atdma_lli_chain(desc, i); + } + break; + case DMA_DEV_TO_MEM: + reg_width = convert_buswidth(sconfig->src_addr_width); + ctrla |= FIELD_PREP(ATC_SRC_WIDTH, reg_width); + ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | + FIELD_PREP(ATC_SRC_ADDR_MODE, + ATC_SRC_ADDR_MODE_FIXED) | + FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | + FIELD_PREP(ATC_SIF, atchan->per_if) | + FIELD_PREP(ATC_DIF, atchan->mem_if); + + reg = sconfig->src_addr; + for_each_sg(sgl, sg, sg_len, i) { + struct atdma_sg *atdma_sg = &desc->sg[i]; + struct at_lli *lli; + u32 len; + u32 mem; + + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, + GFP_NOWAIT, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) + goto err_desc_get; + lli = atdma_sg->lli; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + if (unlikely(!len)) { + dev_dbg(chan2dev(chan), + "prep_slave_sg: sg(%d) data length is zero\n", i); + goto err; + } + mem_width = 2; + if (unlikely(mem & 3 || len & 3)) + mem_width = 0; + + lli->saddr = reg; + lli->daddr = mem; + lli->ctrla = ctrla | + FIELD_PREP(ATC_DST_WIDTH, mem_width) | + len >> reg_width; + lli->ctrlb = ctrlb; + + desc->sg[i].len = len; + total_len += len; + + atdma_lli_chain(desc, i); + } + break; + default: + return NULL; + } + + /* set end-of-link to the last link descriptor of list*/ + set_lli_eol(desc, i - 1); + + desc->total_len = total_len; + + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); + +err_desc_get: + dev_err(chan2dev(chan), "not enough descriptors available\n"); +err: + atdma_desc_free(&desc->vd); + return NULL; +} + +/* + * atc_dma_cyclic_check_values + * Check for too big/unaligned periods and unaligned DMA buffer + */ +static int +atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr, + size_t period_len) +{ + if (period_len > (ATC_BTSIZE_MAX << reg_width)) + goto err_out; + if (unlikely(period_len & ((1 << reg_width) - 1))) + goto err_out; + if (unlikely(buf_addr & ((1 << reg_width) - 1))) + goto err_out; + + return 0; + +err_out: + return -EINVAL; +} + +/* + * atc_dma_cyclic_fill_desc - Fill one period descriptor + */ +static int +atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, + unsigned int i, dma_addr_t buf_addr, + unsigned int reg_width, size_t period_len, + enum dma_transfer_direction direction) +{ + struct at_dma *atdma = to_at_dma(chan->device); + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct dma_slave_config *sconfig = &atchan->dma_sconfig; + struct atdma_sg *atdma_sg = &desc->sg[i]; + struct at_lli *lli; + + atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC, + &atdma_sg->lli_phys); + if (!atdma_sg->lli) + return -ENOMEM; + lli = atdma_sg->lli; + + switch (direction) { + case DMA_MEM_TO_DEV: + lli->saddr = buf_addr + (period_len * i); + lli->daddr = sconfig->dst_addr; + lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, + ATC_DST_ADDR_MODE_FIXED) | + FIELD_PREP(ATC_SRC_ADDR_MODE, + ATC_SRC_ADDR_MODE_INCR) | + FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | + FIELD_PREP(ATC_SIF, atchan->mem_if) | + FIELD_PREP(ATC_DIF, atchan->per_if); + + break; + + case DMA_DEV_TO_MEM: + lli->saddr = sconfig->src_addr; + lli->daddr = buf_addr + (period_len * i); + lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, + ATC_DST_ADDR_MODE_INCR) | + FIELD_PREP(ATC_SRC_ADDR_MODE, + ATC_SRC_ADDR_MODE_FIXED) | + FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | + FIELD_PREP(ATC_SIF, atchan->per_if) | + FIELD_PREP(ATC_DIF, atchan->mem_if); + break; + + default: + return -EINVAL; + } + + lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | + FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) | + FIELD_PREP(ATC_DST_WIDTH, reg_width) | + FIELD_PREP(ATC_SRC_WIDTH, reg_width) | + period_len >> reg_width; + desc->sg[i].len = period_len; + + return 0; +} + +/** + * atc_prep_dma_cyclic - prepare the cyclic DMA transfer + * @chan: the DMA channel to prepare + * @buf_addr: physical DMA address where the buffer starts + * @buf_len: total number of bytes for the entire buffer + * @period_len: number of bytes for each period + * @direction: transfer direction, to or from device + * @flags: tx descriptor status flags + */ +static struct dma_async_tx_descriptor * +atc_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 at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma_slave *atslave = chan->private; + struct dma_slave_config *sconfig = &atchan->dma_sconfig; + struct at_desc *desc; + unsigned long was_cyclic; + unsigned int reg_width; + unsigned int periods = buf_len / period_len; + unsigned int i; + + dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n", + direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", + &buf_addr, + periods, buf_len, period_len); + + if (unlikely(!atslave || !buf_len || !period_len)) { + dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n"); + return NULL; + } + + was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status); + if (was_cyclic) { + dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n"); + return NULL; + } + + if (unlikely(!is_slave_direction(direction))) + goto err_out; + + if (direction == DMA_MEM_TO_DEV) + reg_width = convert_buswidth(sconfig->dst_addr_width); + else + reg_width = convert_buswidth(sconfig->src_addr_width); + + /* Check for too big/unaligned periods and unaligned DMA buffer */ + if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len)) + goto err_out; + + desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC); + if (!desc) + goto err_out; + desc->sglen = periods; + + /* build cyclic linked list */ + for (i = 0; i < periods; i++) { + if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr, + reg_width, period_len, direction)) + goto err_fill_desc; + atdma_lli_chain(desc, i); + } + desc->total_len = buf_len; + /* lets make a cyclic list */ + desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys; + + return vchan_tx_prep(&atchan->vc, &desc->vd, flags); + +err_fill_desc: + atdma_desc_free(&desc->vd); +err_out: + clear_bit(ATC_IS_CYCLIC, &atchan->status); + return NULL; +} + +static int atc_config(struct dma_chan *chan, + struct dma_slave_config *sconfig) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + /* Check if it is chan is configured for slave transfers */ + if (!chan->private) + return -EINVAL; + + memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig)); + + convert_burst(&atchan->dma_sconfig.src_maxburst); + convert_burst(&atchan->dma_sconfig.dst_maxburst); + + return 0; +} + +static int atc_pause(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + int chan_id = atchan->vc.chan.chan_id; + unsigned long flags; + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + spin_lock_irqsave(&atchan->vc.lock, flags); + + dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id)); + set_bit(ATC_IS_PAUSED, &atchan->status); + + spin_unlock_irqrestore(&atchan->vc.lock, flags); + + return 0; +} + +static int atc_resume(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + int chan_id = atchan->vc.chan.chan_id; + unsigned long flags; + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + if (!atc_chan_is_paused(atchan)) + return 0; + + spin_lock_irqsave(&atchan->vc.lock, flags); + + dma_writel(atdma, CHDR, AT_DMA_RES(chan_id)); + clear_bit(ATC_IS_PAUSED, &atchan->status); + + spin_unlock_irqrestore(&atchan->vc.lock, flags); + + return 0; +} + +static int atc_terminate_all(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + int chan_id = atchan->vc.chan.chan_id; + unsigned long flags; + + LIST_HEAD(list); + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + /* + * This is only called when something went wrong elsewhere, so + * we don't really care about the data. Just disable the + * channel. We still have to poll the channel enable bit due + * to AHB/HSB limitations. + */ + spin_lock_irqsave(&atchan->vc.lock, flags); + + /* disabling channel: must also remove suspend state */ + dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask); + + /* confirm that this channel is disabled */ + while (dma_readl(atdma, CHSR) & atchan->mask) + cpu_relax(); + + if (atchan->desc) { + vchan_terminate_vdesc(&atchan->desc->vd); + atchan->desc = NULL; + } + + vchan_get_all_descriptors(&atchan->vc, &list); + + clear_bit(ATC_IS_PAUSED, &atchan->status); + /* if channel dedicated to cyclic operations, free it */ + clear_bit(ATC_IS_CYCLIC, &atchan->status); + + spin_unlock_irqrestore(&atchan->vc.lock, flags); + + vchan_dma_desc_free_list(&atchan->vc, &list); + + return 0; +} + +/** + * atc_tx_status - poll for transaction completion + * @chan: DMA channel + * @cookie: transaction identifier to check status of + * @txstate: if not %NULL updated with transaction state + * + * If @txstate is passed in, upon return it reflect the driver + * internal state and can be used with dma_async_is_complete() to check + * the status of multiple cookies without re-checking hardware state. + */ +static enum dma_status +atc_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + unsigned long flags; + enum dma_status dma_status; + u32 residue; + int ret; + + dma_status = dma_cookie_status(chan, cookie, txstate); + if (dma_status == DMA_COMPLETE || !txstate) + return dma_status; + + spin_lock_irqsave(&atchan->vc.lock, flags); + /* Get number of bytes left in the active transactions */ + ret = atc_get_residue(chan, cookie, &residue); + spin_unlock_irqrestore(&atchan->vc.lock, flags); + + if (unlikely(ret < 0)) { + dev_vdbg(chan2dev(chan), "get residual bytes error\n"); + return DMA_ERROR; + } else { + dma_set_residue(txstate, residue); + } + + dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %u\n", + dma_status, cookie, residue); + + return dma_status; +} + +static void atc_issue_pending(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&atchan->vc.lock, flags); + if (vchan_issue_pending(&atchan->vc) && !atchan->desc) { + if (!(atc_chan_is_enabled(atchan))) + atc_dostart(atchan); + } + spin_unlock_irqrestore(&atchan->vc.lock, flags); +} + +/** + * atc_alloc_chan_resources - allocate resources for DMA channel + * @chan: allocate descriptor resources for this channel + * + * return - the number of allocated descriptors + */ +static int atc_alloc_chan_resources(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + struct at_dma_slave *atslave; + u32 cfg; + + dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); + + /* ASSERT: channel is idle */ + if (atc_chan_is_enabled(atchan)) { + dev_dbg(chan2dev(chan), "DMA channel not idle ?\n"); + return -EIO; + } + + cfg = ATC_DEFAULT_CFG; + + atslave = chan->private; + if (atslave) { + /* + * We need controller-specific data to set up slave + * transfers. + */ + BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_device.dev); + + /* if cfg configuration specified take it instead of default */ + if (atslave->cfg) + cfg = atslave->cfg; + } + + /* channel parameters */ + channel_writel(atchan, CFG, cfg); + + return 0; +} + +/** + * atc_free_chan_resources - free all channel resources + * @chan: DMA channel + */ +static void atc_free_chan_resources(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + BUG_ON(atc_chan_is_enabled(atchan)); + + vchan_free_chan_resources(to_virt_chan(chan)); + atchan->status = 0; + + /* + * Free atslave allocated in at_dma_xlate() + */ + kfree(chan->private); + chan->private = NULL; + + dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); +} + +#ifdef CONFIG_OF +static bool at_dma_filter(struct dma_chan *chan, void *slave) +{ + struct at_dma_slave *atslave = slave; + + if (atslave->dma_dev == chan->device->dev) { + chan->private = atslave; + return true; + } else { + return false; + } +} + +static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *of_dma) +{ + struct dma_chan *chan; + struct at_dma_chan *atchan; + struct at_dma_slave *atslave; + dma_cap_mask_t mask; + unsigned int per_id; + struct platform_device *dmac_pdev; + + if (dma_spec->args_count != 2) + return NULL; + + dmac_pdev = of_find_device_by_node(dma_spec->np); + if (!dmac_pdev) + return NULL; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + atslave = kmalloc(sizeof(*atslave), GFP_KERNEL); + if (!atslave) { + put_device(&dmac_pdev->dev); + return NULL; + } + + atslave->cfg = ATC_DST_H2SEL | ATC_SRC_H2SEL; + /* + * We can fill both SRC_PER and DST_PER, one of these fields will be + * ignored depending on DMA transfer direction. + */ + per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; + atslave->cfg |= ATC_DST_PER_ID(per_id) | ATC_SRC_PER_ID(per_id); + /* + * We have to translate the value we get from the device tree since + * the half FIFO configuration value had to be 0 to keep backward + * compatibility. + */ + switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { + case AT91_DMA_CFG_FIFOCFG_ALAP: + atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, + ATC_FIFOCFG_LARGESTBURST); + break; + case AT91_DMA_CFG_FIFOCFG_ASAP: + atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, + ATC_FIFOCFG_ENOUGHSPACE); + break; + case AT91_DMA_CFG_FIFOCFG_HALF: + default: + atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO); + } + atslave->dma_dev = &dmac_pdev->dev; + + chan = dma_request_channel(mask, at_dma_filter, atslave); + if (!chan) { + put_device(&dmac_pdev->dev); + kfree(atslave); + return NULL; + } + + atchan = to_at_dma_chan(chan); + atchan->per_if = dma_spec->args[0] & 0xff; + atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff; + + return chan; +} +#else +static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *of_dma) +{ + return NULL; +} +#endif + +/*-- Module Management -----------------------------------------------*/ + +/* cap_mask is a multi-u32 bitfield, fill it with proper C code. */ +static struct at_dma_platform_data at91sam9rl_config = { + .nr_channels = 2, +}; +static struct at_dma_platform_data at91sam9g45_config = { + .nr_channels = 8, +}; + +#if defined(CONFIG_OF) +static const struct of_device_id atmel_dma_dt_ids[] = { + { + .compatible = "atmel,at91sam9rl-dma", + .data = &at91sam9rl_config, + }, { + .compatible = "atmel,at91sam9g45-dma", + .data = &at91sam9g45_config, + }, { + /* sentinel */ + } +}; + +MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids); +#endif + +static const struct platform_device_id atdma_devtypes[] = { + { + .name = "at91sam9rl_dma", + .driver_data = (unsigned long) &at91sam9rl_config, + }, { + .name = "at91sam9g45_dma", + .driver_data = (unsigned long) &at91sam9g45_config, + }, { + /* sentinel */ + } +}; + +static inline const struct at_dma_platform_data * __init at_dma_get_driver_data( + struct platform_device *pdev) +{ + if (pdev->dev.of_node) { + const struct of_device_id *match; + match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node); + if (match == NULL) + return NULL; + return match->data; + } + return (struct at_dma_platform_data *) + platform_get_device_id(pdev)->driver_data; +} + +/** + * at_dma_off - disable DMA controller + * @atdma: the Atmel HDAMC device + */ +static void at_dma_off(struct at_dma *atdma) +{ + dma_writel(atdma, EN, 0); + + /* disable all interrupts */ + dma_writel(atdma, EBCIDR, -1L); + + /* confirm that all channels are disabled */ + while (dma_readl(atdma, CHSR) & atdma->all_chan_mask) + cpu_relax(); +} + +static int __init at_dma_probe(struct platform_device *pdev) +{ + struct at_dma *atdma; + int irq; + int err; + int i; + const struct at_dma_platform_data *plat_dat; + + /* setup platform data for each SoC */ + dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask); + dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask); + + /* get DMA parameters from controller type */ + plat_dat = at_dma_get_driver_data(pdev); + if (!plat_dat) + return -ENODEV; + + atdma = devm_kzalloc(&pdev->dev, + struct_size(atdma, chan, plat_dat->nr_channels), + GFP_KERNEL); + if (!atdma) + return -ENOMEM; + + atdma->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(atdma->regs)) + return PTR_ERR(atdma->regs); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + /* discover transaction capabilities */ + atdma->dma_device.cap_mask = plat_dat->cap_mask; + atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1; + + atdma->clk = devm_clk_get(&pdev->dev, "dma_clk"); + if (IS_ERR(atdma->clk)) + return PTR_ERR(atdma->clk); + + err = clk_prepare_enable(atdma->clk); + if (err) + return err; + + /* force dma off, just in case */ + at_dma_off(atdma); + + err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma); + if (err) + goto err_irq; + + platform_set_drvdata(pdev, atdma); + + /* create a pool of consistent memory blocks for hardware descriptors */ + atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool", + &pdev->dev, sizeof(struct at_lli), + 4 /* word alignment */, 0); + if (!atdma->lli_pool) { + dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n"); + err = -ENOMEM; + goto err_desc_pool_create; + } + + /* create a pool of consistent memory blocks for memset blocks */ + atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool", + &pdev->dev, sizeof(int), 4, 0); + if (!atdma->memset_pool) { + dev_err(&pdev->dev, "No memory for memset dma pool\n"); + err = -ENOMEM; + goto err_memset_pool_create; + } + + /* clear any pending interrupt */ + while (dma_readl(atdma, EBCISR)) + cpu_relax(); + + /* initialize channels related values */ + INIT_LIST_HEAD(&atdma->dma_device.channels); + for (i = 0; i < plat_dat->nr_channels; i++) { + struct at_dma_chan *atchan = &atdma->chan[i]; + + atchan->mem_if = AT_DMA_MEM_IF; + atchan->per_if = AT_DMA_PER_IF; + + atchan->ch_regs = atdma->regs + ch_regs(i); + atchan->mask = 1 << i; + + atchan->atdma = atdma; + atchan->vc.desc_free = atdma_desc_free; + vchan_init(&atchan->vc, &atdma->dma_device); + atc_enable_chan_irq(atdma, i); + } + + /* set base routines */ + atdma->dma_device.device_alloc_chan_resources = atc_alloc_chan_resources; + atdma->dma_device.device_free_chan_resources = atc_free_chan_resources; + atdma->dma_device.device_tx_status = atc_tx_status; + atdma->dma_device.device_issue_pending = atc_issue_pending; + atdma->dma_device.dev = &pdev->dev; + + /* set prep routines based on capability */ + if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_device.cap_mask)) + atdma->dma_device.device_prep_interleaved_dma = atc_prep_dma_interleaved; + + if (dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask)) + atdma->dma_device.device_prep_dma_memcpy = atc_prep_dma_memcpy; + + if (dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask)) { + atdma->dma_device.device_prep_dma_memset = atc_prep_dma_memset; + atdma->dma_device.device_prep_dma_memset_sg = atc_prep_dma_memset_sg; + atdma->dma_device.fill_align = DMAENGINE_ALIGN_4_BYTES; + } + + if (dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask)) { + atdma->dma_device.device_prep_slave_sg = atc_prep_slave_sg; + /* controller can do slave DMA: can trigger cyclic transfers */ + dma_cap_set(DMA_CYCLIC, atdma->dma_device.cap_mask); + atdma->dma_device.device_prep_dma_cyclic = atc_prep_dma_cyclic; + atdma->dma_device.device_config = atc_config; + atdma->dma_device.device_pause = atc_pause; + atdma->dma_device.device_resume = atc_resume; + atdma->dma_device.device_terminate_all = atc_terminate_all; + atdma->dma_device.src_addr_widths = ATC_DMA_BUSWIDTHS; + atdma->dma_device.dst_addr_widths = ATC_DMA_BUSWIDTHS; + atdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + atdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + } + + dma_writel(atdma, EN, AT_DMA_ENABLE); + + dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n", + dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask) ? "cpy " : "", + dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask) ? "set " : "", + dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask) ? "slave " : "", + plat_dat->nr_channels); + + err = dma_async_device_register(&atdma->dma_device); + if (err) { + dev_err(&pdev->dev, "Unable to register: %d.\n", err); + goto err_dma_async_device_register; + } + + /* + * Do not return an error if the dmac node is not present in order to + * not break the existing way of requesting channel with + * dma_request_channel(). + */ + if (pdev->dev.of_node) { + err = of_dma_controller_register(pdev->dev.of_node, + at_dma_xlate, atdma); + if (err) { + dev_err(&pdev->dev, "could not register of_dma_controller\n"); + goto err_of_dma_controller_register; + } + } + + return 0; + +err_of_dma_controller_register: + dma_async_device_unregister(&atdma->dma_device); +err_dma_async_device_register: + dma_pool_destroy(atdma->memset_pool); +err_memset_pool_create: + dma_pool_destroy(atdma->lli_pool); +err_desc_pool_create: + free_irq(platform_get_irq(pdev, 0), atdma); +err_irq: + clk_disable_unprepare(atdma->clk); + return err; +} + +static int at_dma_remove(struct platform_device *pdev) +{ + struct at_dma *atdma = platform_get_drvdata(pdev); + struct dma_chan *chan, *_chan; + + at_dma_off(atdma); + if (pdev->dev.of_node) + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&atdma->dma_device); + + dma_pool_destroy(atdma->memset_pool); + dma_pool_destroy(atdma->lli_pool); + free_irq(platform_get_irq(pdev, 0), atdma); + + list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, + device_node) { + /* Disable interrupts */ + atc_disable_chan_irq(atdma, chan->chan_id); + list_del(&chan->device_node); + } + + clk_disable_unprepare(atdma->clk); + + return 0; +} + +static void at_dma_shutdown(struct platform_device *pdev) +{ + struct at_dma *atdma = platform_get_drvdata(pdev); + + at_dma_off(platform_get_drvdata(pdev)); + clk_disable_unprepare(atdma->clk); +} + +static int at_dma_prepare(struct device *dev) +{ + struct at_dma *atdma = dev_get_drvdata(dev); + struct dma_chan *chan, *_chan; + + list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + /* wait for transaction completion (except in cyclic case) */ + if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan)) + return -EAGAIN; + } + return 0; +} + +static void atc_suspend_cyclic(struct at_dma_chan *atchan) +{ + struct dma_chan *chan = &atchan->vc.chan; + + /* Channel should be paused by user + * do it anyway even if it is not done already */ + if (!atc_chan_is_paused(atchan)) { + dev_warn(chan2dev(chan), + "cyclic channel not paused, should be done by channel user\n"); + atc_pause(chan); + } + + /* now preserve additional data for cyclic operations */ + /* next descriptor address in the cyclic list */ + atchan->save_dscr = channel_readl(atchan, DSCR); + + vdbg_dump_regs(atchan); +} + +static int at_dma_suspend_noirq(struct device *dev) +{ + struct at_dma *atdma = dev_get_drvdata(dev); + struct dma_chan *chan, *_chan; + + /* preserve data */ + list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + if (atc_chan_is_cyclic(atchan)) + atc_suspend_cyclic(atchan); + atchan->save_cfg = channel_readl(atchan, CFG); + } + atdma->save_imr = dma_readl(atdma, EBCIMR); + + /* disable DMA controller */ + at_dma_off(atdma); + clk_disable_unprepare(atdma->clk); + return 0; +} + +static void atc_resume_cyclic(struct at_dma_chan *atchan) +{ + struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); + + /* restore channel status for cyclic descriptors list: + * next descriptor in the cyclic list at the time of suspend */ + channel_writel(atchan, SADDR, 0); + channel_writel(atchan, DADDR, 0); + channel_writel(atchan, CTRLA, 0); + channel_writel(atchan, CTRLB, 0); + channel_writel(atchan, DSCR, atchan->save_dscr); + dma_writel(atdma, CHER, atchan->mask); + + /* channel pause status should be removed by channel user + * We cannot take the initiative to do it here */ + + vdbg_dump_regs(atchan); +} + +static int at_dma_resume_noirq(struct device *dev) +{ + struct at_dma *atdma = dev_get_drvdata(dev); + struct dma_chan *chan, *_chan; + + /* bring back DMA controller */ + clk_prepare_enable(atdma->clk); + dma_writel(atdma, EN, AT_DMA_ENABLE); + + /* clear any pending interrupt */ + while (dma_readl(atdma, EBCISR)) + cpu_relax(); + + /* restore saved data */ + dma_writel(atdma, EBCIER, atdma->save_imr); + list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, + device_node) { + struct at_dma_chan *atchan = to_at_dma_chan(chan); + + channel_writel(atchan, CFG, atchan->save_cfg); + if (atc_chan_is_cyclic(atchan)) + atc_resume_cyclic(atchan); + } + return 0; +} + +static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = { + .prepare = at_dma_prepare, + .suspend_noirq = at_dma_suspend_noirq, + .resume_noirq = at_dma_resume_noirq, +}; + +static struct platform_driver at_dma_driver = { + .remove = at_dma_remove, + .shutdown = at_dma_shutdown, + .id_table = atdma_devtypes, + .driver = { + .name = "at_hdmac", + .pm = pm_ptr(&at_dma_dev_pm_ops), + .of_match_table = of_match_ptr(atmel_dma_dt_ids), + }, +}; + +static int __init at_dma_init(void) +{ + return platform_driver_probe(&at_dma_driver, at_dma_probe); +} +subsys_initcall(at_dma_init); + +static void __exit at_dma_exit(void) +{ + platform_driver_unregister(&at_dma_driver); +} +module_exit(at_dma_exit); + +MODULE_DESCRIPTION("Atmel AHB DMA Controller driver"); +MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>"); +MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:at_hdmac"); |