diff options
Diffstat (limited to 'drivers/dma/dw/core.c')
| -rw-r--r-- | drivers/dma/dw/core.c | 1319 |
1 files changed, 1319 insertions, 0 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c new file mode 100644 index 0000000000..5f7d690e3d --- /dev/null +++ b/drivers/dma/dw/core.c @@ -0,0 +1,1319 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Core driver for the Synopsys DesignWare DMA Controller + * + * Copyright (C) 2007-2008 Atmel Corporation + * Copyright (C) 2010-2011 ST Microelectronics + * Copyright (C) 2013 Intel Corporation + */ + +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/dmapool.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/pm_runtime.h> + +#include "../dmaengine.h" +#include "internal.h" + +/* + * This supports the Synopsys "DesignWare AHB Central DMA Controller", + * (DW_ahb_dmac) which is used with various AMBA 2.0 systems (not all + * of which use ARM any more). See the "Databook" from Synopsys for + * information beyond what licensees probably provide. + */ + +/* The set of bus widths supported by the DMA controller */ +#define DW_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) + +/*----------------------------------------------------------------------*/ + +static struct device *chan2dev(struct dma_chan *chan) +{ + return &chan->dev->device; +} + +static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc) +{ + return to_dw_desc(dwc->active_list.next); +} + +static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct dw_desc *desc = txd_to_dw_desc(tx); + struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan); + dma_cookie_t cookie; + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + cookie = dma_cookie_assign(tx); + + /* + * REVISIT: We should attempt to chain as many descriptors as + * possible, perhaps even appending to those already submitted + * for DMA. But this is hard to do in a race-free manner. + */ + + list_add_tail(&desc->desc_node, &dwc->queue); + spin_unlock_irqrestore(&dwc->lock, flags); + dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", + __func__, desc->txd.cookie); + + return cookie; +} + +static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_desc *desc; + dma_addr_t phys; + + desc = dma_pool_zalloc(dw->desc_pool, GFP_ATOMIC, &phys); + if (!desc) + return NULL; + + dwc->descs_allocated++; + INIT_LIST_HEAD(&desc->tx_list); + dma_async_tx_descriptor_init(&desc->txd, &dwc->chan); + desc->txd.tx_submit = dwc_tx_submit; + desc->txd.flags = DMA_CTRL_ACK; + desc->txd.phys = phys; + return desc; +} + +static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_desc *child, *_next; + + if (unlikely(!desc)) + return; + + list_for_each_entry_safe(child, _next, &desc->tx_list, desc_node) { + list_del(&child->desc_node); + dma_pool_free(dw->desc_pool, child, child->txd.phys); + dwc->descs_allocated--; + } + + dma_pool_free(dw->desc_pool, desc, desc->txd.phys); + dwc->descs_allocated--; +} + +static void dwc_initialize(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + + dw->initialize_chan(dwc); + + /* Enable interrupts */ + channel_set_bit(dw, MASK.XFER, dwc->mask); + channel_set_bit(dw, MASK.ERROR, dwc->mask); +} + +/*----------------------------------------------------------------------*/ + +static inline void dwc_dump_chan_regs(struct dw_dma_chan *dwc) +{ + dev_err(chan2dev(&dwc->chan), + " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n", + channel_readl(dwc, SAR), + channel_readl(dwc, DAR), + channel_readl(dwc, LLP), + channel_readl(dwc, CTL_HI), + channel_readl(dwc, CTL_LO)); +} + +static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc) +{ + channel_clear_bit(dw, CH_EN, dwc->mask); + while (dma_readl(dw, CH_EN) & dwc->mask) + cpu_relax(); +} + +/*----------------------------------------------------------------------*/ + +/* Perform single block transfer */ +static inline void dwc_do_single_block(struct dw_dma_chan *dwc, + struct dw_desc *desc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + u32 ctllo; + + /* + * Software emulation of LLP mode relies on interrupts to continue + * multi block transfer. + */ + ctllo = lli_read(desc, ctllo) | DWC_CTLL_INT_EN; + + channel_writel(dwc, SAR, lli_read(desc, sar)); + channel_writel(dwc, DAR, lli_read(desc, dar)); + channel_writel(dwc, CTL_LO, ctllo); + channel_writel(dwc, CTL_HI, lli_read(desc, ctlhi)); + channel_set_bit(dw, CH_EN, dwc->mask); + + /* Move pointer to next descriptor */ + dwc->tx_node_active = dwc->tx_node_active->next; +} + +/* Called with dwc->lock held and bh disabled */ +static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + u8 lms = DWC_LLP_LMS(dwc->dws.m_master); + unsigned long was_soft_llp; + + /* ASSERT: channel is idle */ + if (dma_readl(dw, CH_EN) & dwc->mask) { + dev_err(chan2dev(&dwc->chan), + "%s: BUG: Attempted to start non-idle channel\n", + __func__); + dwc_dump_chan_regs(dwc); + + /* The tasklet will hopefully advance the queue... */ + return; + } + + if (dwc->nollp) { + was_soft_llp = test_and_set_bit(DW_DMA_IS_SOFT_LLP, + &dwc->flags); + if (was_soft_llp) { + dev_err(chan2dev(&dwc->chan), + "BUG: Attempted to start new LLP transfer inside ongoing one\n"); + return; + } + + dwc_initialize(dwc); + + first->residue = first->total_len; + dwc->tx_node_active = &first->tx_list; + + /* Submit first block */ + dwc_do_single_block(dwc, first); + + return; + } + + dwc_initialize(dwc); + + channel_writel(dwc, LLP, first->txd.phys | lms); + channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); + channel_writel(dwc, CTL_HI, 0); + channel_set_bit(dw, CH_EN, dwc->mask); +} + +static void dwc_dostart_first_queued(struct dw_dma_chan *dwc) +{ + struct dw_desc *desc; + + if (list_empty(&dwc->queue)) + return; + + list_move(dwc->queue.next, &dwc->active_list); + desc = dwc_first_active(dwc); + dev_vdbg(chan2dev(&dwc->chan), "%s: started %u\n", __func__, desc->txd.cookie); + dwc_dostart(dwc, desc); +} + +/*----------------------------------------------------------------------*/ + +static void +dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc, + bool callback_required) +{ + struct dma_async_tx_descriptor *txd = &desc->txd; + struct dw_desc *child; + unsigned long flags; + struct dmaengine_desc_callback cb; + + dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie); + + spin_lock_irqsave(&dwc->lock, flags); + dma_cookie_complete(txd); + if (callback_required) + dmaengine_desc_get_callback(txd, &cb); + else + memset(&cb, 0, sizeof(cb)); + + /* async_tx_ack */ + list_for_each_entry(child, &desc->tx_list, desc_node) + async_tx_ack(&child->txd); + async_tx_ack(&desc->txd); + dwc_desc_put(dwc, desc); + spin_unlock_irqrestore(&dwc->lock, flags); + + dmaengine_desc_callback_invoke(&cb, NULL); +} + +static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc) +{ + struct dw_desc *desc, *_desc; + LIST_HEAD(list); + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + if (dma_readl(dw, CH_EN) & dwc->mask) { + dev_err(chan2dev(&dwc->chan), + "BUG: XFER bit set, but channel not idle!\n"); + + /* Try to continue after resetting the channel... */ + dwc_chan_disable(dw, dwc); + } + + /* + * Submit queued descriptors ASAP, i.e. before we go through + * the completed ones. + */ + list_splice_init(&dwc->active_list, &list); + dwc_dostart_first_queued(dwc); + + spin_unlock_irqrestore(&dwc->lock, flags); + + list_for_each_entry_safe(desc, _desc, &list, desc_node) + dwc_descriptor_complete(dwc, desc, true); +} + +/* Returns how many bytes were already received from source */ +static inline u32 dwc_get_sent(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + u32 ctlhi = channel_readl(dwc, CTL_HI); + u32 ctllo = channel_readl(dwc, CTL_LO); + + return dw->block2bytes(dwc, ctlhi, ctllo >> 4 & 7); +} + +static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) +{ + dma_addr_t llp; + struct dw_desc *desc, *_desc; + struct dw_desc *child; + u32 status_xfer; + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + llp = channel_readl(dwc, LLP); + status_xfer = dma_readl(dw, RAW.XFER); + + if (status_xfer & dwc->mask) { + /* Everything we've submitted is done */ + dma_writel(dw, CLEAR.XFER, dwc->mask); + + if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) { + struct list_head *head, *active = dwc->tx_node_active; + + /* + * We are inside first active descriptor. + * Otherwise something is really wrong. + */ + desc = dwc_first_active(dwc); + + head = &desc->tx_list; + if (active != head) { + /* Update residue to reflect last sent descriptor */ + if (active == head->next) + desc->residue -= desc->len; + else + desc->residue -= to_dw_desc(active->prev)->len; + + child = to_dw_desc(active); + + /* Submit next block */ + dwc_do_single_block(dwc, child); + + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + /* We are done here */ + clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags); + } + + spin_unlock_irqrestore(&dwc->lock, flags); + + dwc_complete_all(dw, dwc); + return; + } + + if (list_empty(&dwc->active_list)) { + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) { + dev_vdbg(chan2dev(&dwc->chan), "%s: soft LLP mode\n", __func__); + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + dev_vdbg(chan2dev(&dwc->chan), "%s: llp=%pad\n", __func__, &llp); + + list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) { + /* Initial residue value */ + desc->residue = desc->total_len; + + /* Check first descriptors addr */ + if (desc->txd.phys == DWC_LLP_LOC(llp)) { + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + /* Check first descriptors llp */ + if (lli_read(desc, llp) == llp) { + /* This one is currently in progress */ + desc->residue -= dwc_get_sent(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + desc->residue -= desc->len; + list_for_each_entry(child, &desc->tx_list, desc_node) { + if (lli_read(child, llp) == llp) { + /* Currently in progress */ + desc->residue -= dwc_get_sent(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + desc->residue -= child->len; + } + + /* + * No descriptors so far seem to be in progress, i.e. + * this one must be done. + */ + spin_unlock_irqrestore(&dwc->lock, flags); + dwc_descriptor_complete(dwc, desc, true); + spin_lock_irqsave(&dwc->lock, flags); + } + + dev_err(chan2dev(&dwc->chan), + "BUG: All descriptors done, but channel not idle!\n"); + + /* Try to continue after resetting the channel... */ + dwc_chan_disable(dw, dwc); + + dwc_dostart_first_queued(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); +} + +static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_desc *desc) +{ + dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n", + lli_read(desc, sar), + lli_read(desc, dar), + lli_read(desc, llp), + lli_read(desc, ctlhi), + lli_read(desc, ctllo)); +} + +static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc) +{ + struct dw_desc *bad_desc; + struct dw_desc *child; + unsigned long flags; + + dwc_scan_descriptors(dw, dwc); + + spin_lock_irqsave(&dwc->lock, flags); + + /* + * The descriptor currently at the head of the active list is + * borked. Since we don't have any way to report errors, we'll + * just have to scream loudly and try to carry on. + */ + bad_desc = dwc_first_active(dwc); + list_del_init(&bad_desc->desc_node); + list_move(dwc->queue.next, dwc->active_list.prev); + + /* Clear the error flag and try to restart the controller */ + dma_writel(dw, CLEAR.ERROR, dwc->mask); + if (!list_empty(&dwc->active_list)) + dwc_dostart(dwc, dwc_first_active(dwc)); + + /* + * WARN 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_WARN(chan2dev(&dwc->chan), "Bad descriptor submitted for DMA!\n" + " cookie: %d\n", bad_desc->txd.cookie); + dwc_dump_lli(dwc, bad_desc); + list_for_each_entry(child, &bad_desc->tx_list, desc_node) + dwc_dump_lli(dwc, child); + + spin_unlock_irqrestore(&dwc->lock, flags); + + /* Pretend the descriptor completed successfully */ + dwc_descriptor_complete(dwc, bad_desc, true); +} + +static void dw_dma_tasklet(struct tasklet_struct *t) +{ + struct dw_dma *dw = from_tasklet(dw, t, tasklet); + struct dw_dma_chan *dwc; + u32 status_xfer; + u32 status_err; + unsigned int i; + + status_xfer = dma_readl(dw, RAW.XFER); + status_err = dma_readl(dw, RAW.ERROR); + + dev_vdbg(dw->dma.dev, "%s: status_err=%x\n", __func__, status_err); + + for (i = 0; i < dw->dma.chancnt; i++) { + dwc = &dw->chan[i]; + if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) + dev_vdbg(dw->dma.dev, "Cyclic xfer is not implemented\n"); + else if (status_err & (1 << i)) + dwc_handle_error(dw, dwc); + else if (status_xfer & (1 << i)) + dwc_scan_descriptors(dw, dwc); + } + + /* Re-enable interrupts */ + channel_set_bit(dw, MASK.XFER, dw->all_chan_mask); + channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask); +} + +static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) +{ + struct dw_dma *dw = dev_id; + u32 status; + + /* Check if we have any interrupt from the DMAC which is not in use */ + if (!dw->in_use) + return IRQ_NONE; + + status = dma_readl(dw, STATUS_INT); + dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status); + + /* Check if we have any interrupt from the DMAC */ + if (!status) + return IRQ_NONE; + + /* + * Just disable the interrupts. We'll turn them back on in the + * softirq handler. + */ + channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); + channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); + channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); + + status = dma_readl(dw, STATUS_INT); + if (status) { + dev_err(dw->dma.dev, + "BUG: Unexpected interrupts pending: 0x%x\n", + status); + + /* Try to recover */ + channel_clear_bit(dw, MASK.XFER, (1 << 8) - 1); + channel_clear_bit(dw, MASK.BLOCK, (1 << 8) - 1); + channel_clear_bit(dw, MASK.SRC_TRAN, (1 << 8) - 1); + channel_clear_bit(dw, MASK.DST_TRAN, (1 << 8) - 1); + channel_clear_bit(dw, MASK.ERROR, (1 << 8) - 1); + } + + tasklet_schedule(&dw->tasklet); + + return IRQ_HANDLED; +} + +/*----------------------------------------------------------------------*/ + +static struct dma_async_tx_descriptor * +dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + struct dw_desc *desc; + struct dw_desc *first; + struct dw_desc *prev; + size_t xfer_count; + size_t offset; + u8 m_master = dwc->dws.m_master; + unsigned int src_width; + unsigned int dst_width; + unsigned int data_width = dw->pdata->data_width[m_master]; + u32 ctllo, ctlhi; + u8 lms = DWC_LLP_LMS(m_master); + + dev_vdbg(chan2dev(chan), + "%s: d%pad s%pad l0x%zx f0x%lx\n", __func__, + &dest, &src, len, flags); + + if (unlikely(!len)) { + dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); + return NULL; + } + + dwc->direction = DMA_MEM_TO_MEM; + + src_width = dst_width = __ffs(data_width | src | dest | len); + + ctllo = dw->prepare_ctllo(dwc) + | DWC_CTLL_DST_WIDTH(dst_width) + | DWC_CTLL_SRC_WIDTH(src_width) + | DWC_CTLL_DST_INC + | DWC_CTLL_SRC_INC + | DWC_CTLL_FC_M2M; + prev = first = NULL; + + for (offset = 0; offset < len; offset += xfer_count) { + desc = dwc_desc_get(dwc); + if (!desc) + goto err_desc_get; + + ctlhi = dw->bytes2block(dwc, len - offset, src_width, &xfer_count); + + lli_write(desc, sar, src + offset); + lli_write(desc, dar, dest + offset); + lli_write(desc, ctllo, ctllo); + lli_write(desc, ctlhi, ctlhi); + desc->len = xfer_count; + + if (!first) { + first = desc; + } else { + lli_write(prev, llp, desc->txd.phys | lms); + list_add_tail(&desc->desc_node, &first->tx_list); + } + prev = desc; + } + + if (flags & DMA_PREP_INTERRUPT) + /* Trigger interrupt after last block */ + lli_set(prev, ctllo, DWC_CTLL_INT_EN); + + prev->lli.llp = 0; + lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); + first->txd.flags = flags; + first->total_len = len; + + return &first->txd; + +err_desc_get: + dwc_desc_put(dwc, first); + return NULL; +} + +static struct dma_async_tx_descriptor * +dwc_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 dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + struct dma_slave_config *sconfig = &dwc->dma_sconfig; + struct dw_desc *prev; + struct dw_desc *first; + u32 ctllo, ctlhi; + u8 m_master = dwc->dws.m_master; + u8 lms = DWC_LLP_LMS(m_master); + dma_addr_t reg; + unsigned int reg_width; + unsigned int mem_width; + unsigned int data_width = dw->pdata->data_width[m_master]; + unsigned int i; + struct scatterlist *sg; + size_t total_len = 0; + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + if (unlikely(!is_slave_direction(direction) || !sg_len)) + return NULL; + + dwc->direction = direction; + + prev = first = NULL; + + switch (direction) { + case DMA_MEM_TO_DEV: + reg_width = __ffs(sconfig->dst_addr_width); + reg = sconfig->dst_addr; + ctllo = dw->prepare_ctllo(dwc) + | DWC_CTLL_DST_WIDTH(reg_width) + | DWC_CTLL_DST_FIX + | DWC_CTLL_SRC_INC; + + ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) : + DWC_CTLL_FC(DW_DMA_FC_D_M2P); + + for_each_sg(sgl, sg, sg_len, i) { + struct dw_desc *desc; + u32 len, mem; + size_t dlen; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + + mem_width = __ffs(data_width | mem | len); + +slave_sg_todev_fill_desc: + desc = dwc_desc_get(dwc); + if (!desc) + goto err_desc_get; + + ctlhi = dw->bytes2block(dwc, len, mem_width, &dlen); + + lli_write(desc, sar, mem); + lli_write(desc, dar, reg); + lli_write(desc, ctlhi, ctlhi); + lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width)); + desc->len = dlen; + + if (!first) { + first = desc; + } else { + lli_write(prev, llp, desc->txd.phys | lms); + list_add_tail(&desc->desc_node, &first->tx_list); + } + prev = desc; + + mem += dlen; + len -= dlen; + total_len += dlen; + + if (len) + goto slave_sg_todev_fill_desc; + } + break; + case DMA_DEV_TO_MEM: + reg_width = __ffs(sconfig->src_addr_width); + reg = sconfig->src_addr; + ctllo = dw->prepare_ctllo(dwc) + | DWC_CTLL_SRC_WIDTH(reg_width) + | DWC_CTLL_DST_INC + | DWC_CTLL_SRC_FIX; + + ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) : + DWC_CTLL_FC(DW_DMA_FC_D_P2M); + + for_each_sg(sgl, sg, sg_len, i) { + struct dw_desc *desc; + u32 len, mem; + size_t dlen; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + +slave_sg_fromdev_fill_desc: + desc = dwc_desc_get(dwc); + if (!desc) + goto err_desc_get; + + ctlhi = dw->bytes2block(dwc, len, reg_width, &dlen); + + lli_write(desc, sar, reg); + lli_write(desc, dar, mem); + lli_write(desc, ctlhi, ctlhi); + mem_width = __ffs(data_width | mem); + lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width)); + desc->len = dlen; + + if (!first) { + first = desc; + } else { + lli_write(prev, llp, desc->txd.phys | lms); + list_add_tail(&desc->desc_node, &first->tx_list); + } + prev = desc; + + mem += dlen; + len -= dlen; + total_len += dlen; + + if (len) + goto slave_sg_fromdev_fill_desc; + } + break; + default: + return NULL; + } + + if (flags & DMA_PREP_INTERRUPT) + /* Trigger interrupt after last block */ + lli_set(prev, ctllo, DWC_CTLL_INT_EN); + + prev->lli.llp = 0; + lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN); + first->total_len = total_len; + + return &first->txd; + +err_desc_get: + dev_err(chan2dev(chan), + "not enough descriptors available. Direction %d\n", direction); + dwc_desc_put(dwc, first); + return NULL; +} + +bool dw_dma_filter(struct dma_chan *chan, void *param) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma_slave *dws = param; + + if (dws->dma_dev != chan->device->dev) + return false; + + /* permit channels in accordance with the channels mask */ + if (dws->channels && !(dws->channels & dwc->mask)) + return false; + + /* We have to copy data since dws can be temporary storage */ + memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave)); + + return true; +} +EXPORT_SYMBOL_GPL(dw_dma_filter); + +static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + + memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig)); + + dwc->dma_sconfig.src_maxburst = + clamp(dwc->dma_sconfig.src_maxburst, 0U, dwc->max_burst); + dwc->dma_sconfig.dst_maxburst = + clamp(dwc->dma_sconfig.dst_maxburst, 0U, dwc->max_burst); + + dw->encode_maxburst(dwc, &dwc->dma_sconfig.src_maxburst); + dw->encode_maxburst(dwc, &dwc->dma_sconfig.dst_maxburst); + + return 0; +} + +static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + unsigned int count = 20; /* timeout iterations */ + + dw->suspend_chan(dwc, drain); + + while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--) + udelay(2); + + set_bit(DW_DMA_IS_PAUSED, &dwc->flags); +} + +static int dwc_pause(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + dwc_chan_pause(dwc, false); + spin_unlock_irqrestore(&dwc->lock, flags); + + return 0; +} + +static inline void dwc_chan_resume(struct dw_dma_chan *dwc, bool drain) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + + dw->resume_chan(dwc, drain); + + clear_bit(DW_DMA_IS_PAUSED, &dwc->flags); +} + +static int dwc_resume(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + + if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags)) + dwc_chan_resume(dwc, false); + + spin_unlock_irqrestore(&dwc->lock, flags); + + return 0; +} + +static int dwc_terminate_all(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + struct dw_desc *desc, *_desc; + unsigned long flags; + LIST_HEAD(list); + + spin_lock_irqsave(&dwc->lock, flags); + + clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags); + + dwc_chan_pause(dwc, true); + + dwc_chan_disable(dw, dwc); + + dwc_chan_resume(dwc, true); + + /* active_list entries will end up before queued entries */ + list_splice_init(&dwc->queue, &list); + list_splice_init(&dwc->active_list, &list); + + spin_unlock_irqrestore(&dwc->lock, flags); + + /* Flush all pending and queued descriptors */ + list_for_each_entry_safe(desc, _desc, &list, desc_node) + dwc_descriptor_complete(dwc, desc, false); + + return 0; +} + +static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c) +{ + struct dw_desc *desc; + + list_for_each_entry(desc, &dwc->active_list, desc_node) + if (desc->txd.cookie == c) + return desc; + + return NULL; +} + +static u32 dwc_get_residue_and_status(struct dw_dma_chan *dwc, dma_cookie_t cookie, + enum dma_status *status) +{ + struct dw_desc *desc; + unsigned long flags; + u32 residue; + + spin_lock_irqsave(&dwc->lock, flags); + + desc = dwc_find_desc(dwc, cookie); + if (desc) { + if (desc == dwc_first_active(dwc)) { + residue = desc->residue; + if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue) + residue -= dwc_get_sent(dwc); + if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags)) + *status = DMA_PAUSED; + } else { + residue = desc->total_len; + } + } else { + residue = 0; + } + + spin_unlock_irqrestore(&dwc->lock, flags); + return residue; +} + +static enum dma_status +dwc_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + enum dma_status ret; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_COMPLETE) + return ret; + + dwc_scan_descriptors(to_dw_dma(chan->device), dwc); + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_COMPLETE) + return ret; + + dma_set_residue(txstate, dwc_get_residue_and_status(dwc, cookie, &ret)); + return ret; +} + +static void dwc_issue_pending(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + if (list_empty(&dwc->active_list)) + dwc_dostart_first_queued(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); +} + +/*----------------------------------------------------------------------*/ + +void do_dw_dma_off(struct dw_dma *dw) +{ + dma_writel(dw, CFG, 0); + + channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); + channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); + channel_clear_bit(dw, MASK.SRC_TRAN, dw->all_chan_mask); + channel_clear_bit(dw, MASK.DST_TRAN, dw->all_chan_mask); + channel_clear_bit(dw, MASK.ERROR, dw->all_chan_mask); + + while (dma_readl(dw, CFG) & DW_CFG_DMA_EN) + cpu_relax(); +} + +void do_dw_dma_on(struct dw_dma *dw) +{ + dma_writel(dw, CFG, DW_CFG_DMA_EN); +} + +static int dwc_alloc_chan_resources(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + + dev_vdbg(chan2dev(chan), "%s\n", __func__); + + /* ASSERT: channel is idle */ + if (dma_readl(dw, CH_EN) & dwc->mask) { + dev_dbg(chan2dev(chan), "DMA channel not idle?\n"); + return -EIO; + } + + dma_cookie_init(chan); + + /* + * NOTE: some controllers may have additional features that we + * need to initialize here, like "scatter-gather" (which + * doesn't mean what you think it means), and status writeback. + */ + + /* + * We need controller-specific data to set up slave transfers. + */ + if (chan->private && !dw_dma_filter(chan, chan->private)) { + dev_warn(chan2dev(chan), "Wrong controller-specific data\n"); + return -EINVAL; + } + + /* Enable controller here if needed */ + if (!dw->in_use) + do_dw_dma_on(dw); + dw->in_use |= dwc->mask; + + return 0; +} + +static void dwc_free_chan_resources(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + unsigned long flags; + + dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__, + dwc->descs_allocated); + + /* ASSERT: channel is idle */ + BUG_ON(!list_empty(&dwc->active_list)); + BUG_ON(!list_empty(&dwc->queue)); + BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask); + + spin_lock_irqsave(&dwc->lock, flags); + + /* Clear custom channel configuration */ + memset(&dwc->dws, 0, sizeof(struct dw_dma_slave)); + + /* Disable interrupts */ + channel_clear_bit(dw, MASK.XFER, dwc->mask); + channel_clear_bit(dw, MASK.BLOCK, dwc->mask); + channel_clear_bit(dw, MASK.ERROR, dwc->mask); + + spin_unlock_irqrestore(&dwc->lock, flags); + + /* Disable controller in case it was a last user */ + dw->in_use &= ~dwc->mask; + if (!dw->in_use) + do_dw_dma_off(dw); + + dev_vdbg(chan2dev(chan), "%s: done\n", __func__); +} + +static void dwc_caps(struct dma_chan *chan, struct dma_slave_caps *caps) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + + caps->max_burst = dwc->max_burst; + + /* + * It might be crucial for some devices to have the hardware + * accelerated multi-block transfers supported, aka LLPs in DW DMAC + * notation. So if LLPs are supported then max_sg_burst is set to + * zero which means unlimited number of SG entries can be handled in a + * single DMA transaction, otherwise it's just one SG entry. + */ + if (dwc->nollp) + caps->max_sg_burst = 1; + else + caps->max_sg_burst = 0; +} + +int do_dma_probe(struct dw_dma_chip *chip) +{ + struct dw_dma *dw = chip->dw; + struct dw_dma_platform_data *pdata; + bool autocfg = false; + unsigned int dw_params; + unsigned int i; + int err; + + dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL); + if (!dw->pdata) + return -ENOMEM; + + dw->regs = chip->regs; + + pm_runtime_get_sync(chip->dev); + + if (!chip->pdata) { + dw_params = dma_readl(dw, DW_PARAMS); + dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params); + + autocfg = dw_params >> DW_PARAMS_EN & 1; + if (!autocfg) { + err = -EINVAL; + goto err_pdata; + } + + /* Reassign the platform data pointer */ + pdata = dw->pdata; + + /* Get hardware configuration parameters */ + pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1; + pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1; + for (i = 0; i < pdata->nr_masters; i++) { + pdata->data_width[i] = + 4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3); + } + pdata->block_size = dma_readl(dw, MAX_BLK_SIZE); + + /* Fill platform data with the default values */ + pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING; + pdata->chan_priority = CHAN_PRIORITY_ASCENDING; + } else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) { + err = -EINVAL; + goto err_pdata; + } else { + memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata)); + + /* Reassign the platform data pointer */ + pdata = dw->pdata; + } + + dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan), + GFP_KERNEL); + if (!dw->chan) { + err = -ENOMEM; + goto err_pdata; + } + + /* Calculate all channel mask before DMA setup */ + dw->all_chan_mask = (1 << pdata->nr_channels) - 1; + + /* Force dma off, just in case */ + dw->disable(dw); + + /* Device and instance ID for IRQ and DMA pool */ + dw->set_device_name(dw, chip->id); + + /* Create a pool of consistent memory blocks for hardware descriptors */ + dw->desc_pool = dmam_pool_create(dw->name, chip->dev, + sizeof(struct dw_desc), 4, 0); + if (!dw->desc_pool) { + dev_err(chip->dev, "No memory for descriptors dma pool\n"); + err = -ENOMEM; + goto err_pdata; + } + + tasklet_setup(&dw->tasklet, dw_dma_tasklet); + + err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED, + dw->name, dw); + if (err) + goto err_pdata; + + INIT_LIST_HEAD(&dw->dma.channels); + for (i = 0; i < pdata->nr_channels; i++) { + struct dw_dma_chan *dwc = &dw->chan[i]; + + dwc->chan.device = &dw->dma; + dma_cookie_init(&dwc->chan); + if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING) + list_add_tail(&dwc->chan.device_node, + &dw->dma.channels); + else + list_add(&dwc->chan.device_node, &dw->dma.channels); + + /* 7 is highest priority & 0 is lowest. */ + if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING) + dwc->priority = pdata->nr_channels - i - 1; + else + dwc->priority = i; + + dwc->ch_regs = &__dw_regs(dw)->CHAN[i]; + spin_lock_init(&dwc->lock); + dwc->mask = 1 << i; + + INIT_LIST_HEAD(&dwc->active_list); + INIT_LIST_HEAD(&dwc->queue); + + channel_clear_bit(dw, CH_EN, dwc->mask); + + dwc->direction = DMA_TRANS_NONE; + + /* Hardware configuration */ + if (autocfg) { + unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1; + void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r]; + unsigned int dwc_params = readl(addr); + + dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i, + dwc_params); + + /* + * Decode maximum block size for given channel. The + * stored 4 bit value represents blocks from 0x00 for 3 + * up to 0x0a for 4095. + */ + dwc->block_size = + (4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1; + + /* + * According to the DW DMA databook the true scatter- + * gether LLPs aren't available if either multi-block + * config is disabled (CHx_MULTI_BLK_EN == 0) or the + * LLP register is hard-coded to zeros + * (CHx_HC_LLP == 1). + */ + dwc->nollp = + (dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0 || + (dwc_params >> DWC_PARAMS_HC_LLP & 0x1) == 1; + dwc->max_burst = + (0x4 << (dwc_params >> DWC_PARAMS_MSIZE & 0x7)); + } else { + dwc->block_size = pdata->block_size; + dwc->nollp = !pdata->multi_block[i]; + dwc->max_burst = pdata->max_burst[i] ?: DW_DMA_MAX_BURST; + } + } + + /* Clear all interrupts on all channels. */ + dma_writel(dw, CLEAR.XFER, dw->all_chan_mask); + dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask); + dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask); + dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask); + dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask); + + /* Set capabilities */ + dma_cap_set(DMA_SLAVE, dw->dma.cap_mask); + dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask); + dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask); + + dw->dma.dev = chip->dev; + dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources; + dw->dma.device_free_chan_resources = dwc_free_chan_resources; + + dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy; + dw->dma.device_prep_slave_sg = dwc_prep_slave_sg; + + dw->dma.device_caps = dwc_caps; + dw->dma.device_config = dwc_config; + dw->dma.device_pause = dwc_pause; + dw->dma.device_resume = dwc_resume; + dw->dma.device_terminate_all = dwc_terminate_all; + + dw->dma.device_tx_status = dwc_tx_status; + dw->dma.device_issue_pending = dwc_issue_pending; + + /* DMA capabilities */ + dw->dma.min_burst = DW_DMA_MIN_BURST; + dw->dma.max_burst = DW_DMA_MAX_BURST; + dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS; + dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS; + dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | + BIT(DMA_MEM_TO_MEM); + dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + + /* + * For now there is no hardware with non uniform maximum block size + * across all of the device channels, so we set the maximum segment + * size as the block size found for the very first channel. + */ + dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size); + + err = dma_async_device_register(&dw->dma); + if (err) + goto err_dma_register; + + dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n", + pdata->nr_channels); + + pm_runtime_put_sync_suspend(chip->dev); + + return 0; + +err_dma_register: + free_irq(chip->irq, dw); +err_pdata: + pm_runtime_put_sync_suspend(chip->dev); + return err; +} + +int do_dma_remove(struct dw_dma_chip *chip) +{ + struct dw_dma *dw = chip->dw; + struct dw_dma_chan *dwc, *_dwc; + + pm_runtime_get_sync(chip->dev); + + do_dw_dma_off(dw); + dma_async_device_unregister(&dw->dma); + + free_irq(chip->irq, dw); + tasklet_kill(&dw->tasklet); + + list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels, + chan.device_node) { + list_del(&dwc->chan.device_node); + channel_clear_bit(dw, CH_EN, dwc->mask); + } + + pm_runtime_put_sync_suspend(chip->dev); + return 0; +} + +int do_dw_dma_disable(struct dw_dma_chip *chip) +{ + struct dw_dma *dw = chip->dw; + + dw->disable(dw); + return 0; +} +EXPORT_SYMBOL_GPL(do_dw_dma_disable); + +int do_dw_dma_enable(struct dw_dma_chip *chip) +{ + struct dw_dma *dw = chip->dw; + + dw->enable(dw); + return 0; +} +EXPORT_SYMBOL_GPL(do_dw_dma_enable); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller core driver"); +MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); +MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>"); |