diff options
Diffstat (limited to 'drivers/dma/dw/core.c')
| -rw-r--r-- | drivers/dma/dw/core.c | 1730 |
1 files changed, 1730 insertions, 0 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c new file mode 100644 index 00000000000..eea479c1217 --- /dev/null +++ b/drivers/dma/dw/core.c @@ -0,0 +1,1730 @@ +/* + * 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 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/bitops.h> +#include <linux/clk.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 "../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 driver has currently been tested only with the Atmel AT32AP7000, + * which does not support descriptor writeback. + */ + +static inline void dwc_set_masters(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_dma_slave *dws = dwc->chan.private; + unsigned char mmax = dw->nr_masters - 1; + + if (dwc->request_line == ~0) { + dwc->src_master = min_t(unsigned char, mmax, dwc_get_sms(dws)); + dwc->dst_master = min_t(unsigned char, mmax, dwc_get_dms(dws)); + } +} + +#define DWC_DEFAULT_CTLLO(_chan) ({ \ + struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan); \ + struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \ + bool _is_slave = is_slave_direction(_dwc->direction); \ + u8 _smsize = _is_slave ? _sconfig->src_maxburst : \ + DW_DMA_MSIZE_16; \ + u8 _dmsize = _is_slave ? _sconfig->dst_maxburst : \ + DW_DMA_MSIZE_16; \ + \ + (DWC_CTLL_DST_MSIZE(_dmsize) \ + | DWC_CTLL_SRC_MSIZE(_smsize) \ + | DWC_CTLL_LLP_D_EN \ + | DWC_CTLL_LLP_S_EN \ + | DWC_CTLL_DMS(_dwc->dst_master) \ + | DWC_CTLL_SMS(_dwc->src_master)); \ + }) + +/* + * Number of descriptors to allocate for each channel. This should be + * made configurable somehow; preferably, the clients (at least the + * ones using slave transfers) should be able to give us a hint. + */ +#define NR_DESCS_PER_CHANNEL 64 + +/*----------------------------------------------------------------------*/ + +static struct device *chan2dev(struct dma_chan *chan) +{ + return &chan->dev->device; +} +static struct device *chan2parent(struct dma_chan *chan) +{ + return chan->dev->device.parent; +} + +static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc) +{ + return to_dw_desc(dwc->active_list.next); +} + +static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) +{ + struct dw_desc *desc, *_desc; + struct dw_desc *ret = NULL; + unsigned int i = 0; + unsigned long flags; + + spin_lock_irqsave(&dwc->lock, flags); + list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) { + i++; + if (async_tx_test_ack(&desc->txd)) { + list_del(&desc->desc_node); + ret = desc; + break; + } + dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc); + } + spin_unlock_irqrestore(&dwc->lock, flags); + + dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i); + + return ret; +} + +/* + * Move a descriptor, including any children, to the free list. + * `desc' must not be on any lists. + */ +static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) +{ + unsigned long flags; + + if (desc) { + struct dw_desc *child; + + spin_lock_irqsave(&dwc->lock, flags); + list_for_each_entry(child, &desc->tx_list, desc_node) + dev_vdbg(chan2dev(&dwc->chan), + "moving child desc %p to freelist\n", + child); + list_splice_init(&desc->tx_list, &dwc->free_list); + dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc); + list_add(&desc->desc_node, &dwc->free_list); + spin_unlock_irqrestore(&dwc->lock, flags); + } +} + +static void dwc_initialize(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_dma_slave *dws = dwc->chan.private; + u32 cfghi = DWC_CFGH_FIFO_MODE; + u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority); + + if (dwc->initialized == true) + return; + + if (dws) { + /* + * We need controller-specific data to set up slave + * transfers. + */ + BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev); + + cfghi = dws->cfg_hi; + cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK; + } else { + if (dwc->direction == DMA_MEM_TO_DEV) + cfghi = DWC_CFGH_DST_PER(dwc->request_line); + else if (dwc->direction == DMA_DEV_TO_MEM) + cfghi = DWC_CFGH_SRC_PER(dwc->request_line); + } + + channel_writel(dwc, CFG_LO, cfglo); + channel_writel(dwc, CFG_HI, cfghi); + + /* Enable interrupts */ + channel_set_bit(dw, MASK.XFER, dwc->mask); + channel_set_bit(dw, MASK.ERROR, dwc->mask); + + dwc->initialized = true; +} + +/*----------------------------------------------------------------------*/ + +static inline unsigned int dwc_fast_fls(unsigned long long v) +{ + /* + * We can be a lot more clever here, but this should take care + * of the most common optimization. + */ + if (!(v & 7)) + return 3; + else if (!(v & 3)) + return 2; + else if (!(v & 1)) + return 1; + return 0; +} + +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 = desc->lli.ctllo | DWC_CTLL_INT_EN; + + channel_writel(dwc, SAR, desc->lli.sar); + channel_writel(dwc, DAR, desc->lli.dar); + channel_writel(dwc, CTL_LO, ctllo); + channel_writel(dwc, CTL_HI, desc->lli.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); + unsigned long was_soft_llp; + + /* ASSERT: channel is idle */ + if (dma_readl(dw, CH_EN) & dwc->mask) { + dev_err(chan2dev(&dwc->chan), + "BUG: Attempted to start non-idle channel\n"); + 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); + + dwc->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); + 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_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc, + bool callback_required) +{ + dma_async_tx_callback callback = NULL; + void *param = NULL; + struct dma_async_tx_descriptor *txd = &desc->txd; + struct dw_desc *child; + unsigned long flags; + + dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie); + + spin_lock_irqsave(&dwc->lock, flags); + dma_cookie_complete(txd); + if (callback_required) { + callback = txd->callback; + param = txd->callback_param; + } + + /* async_tx_ack */ + list_for_each_entry(child, &desc->tx_list, desc_node) + async_tx_ack(&child->txd); + async_tx_ack(&desc->txd); + + list_splice_init(&desc->tx_list, &dwc->free_list); + list_move(&desc->desc_node, &dwc->free_list); + + if (!is_slave_direction(dwc->direction)) { + struct device *parent = chan2parent(&dwc->chan); + if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) { + if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE) + dma_unmap_single(parent, desc->lli.dar, + desc->total_len, DMA_FROM_DEVICE); + else + dma_unmap_page(parent, desc->lli.dar, + desc->total_len, DMA_FROM_DEVICE); + } + if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) { + if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE) + dma_unmap_single(parent, desc->lli.sar, + desc->total_len, DMA_TO_DEVICE); + else + dma_unmap_page(parent, desc->lli.sar, + desc->total_len, DMA_TO_DEVICE); + } + } + + spin_unlock_irqrestore(&dwc->lock, flags); + + if (callback) + callback(param); +} + +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); + if (!list_empty(&dwc->queue)) { + list_move(dwc->queue.next, &dwc->active_list); + dwc_dostart(dwc, dwc_first_active(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) +{ + u32 ctlhi = channel_readl(dwc, CTL_HI); + u32 ctllo = channel_readl(dwc, CTL_LO); + + return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (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 desc to reflect last sent one */ + if (active != head->next) + desc = to_dw_desc(active->prev); + + dwc->residue -= desc->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); + } + + dwc->residue = 0; + + spin_unlock_irqrestore(&dwc->lock, flags); + + dwc_complete_all(dw, dwc); + return; + } + + if (list_empty(&dwc->active_list)) { + dwc->residue = 0; + 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=0x%llx\n", __func__, + (unsigned long long)llp); + + list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) { + /* Initial residue value */ + dwc->residue = desc->total_len; + + /* Check first descriptors addr */ + if (desc->txd.phys == llp) { + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + /* Check first descriptors llp */ + if (desc->lli.llp == llp) { + /* This one is currently in progress */ + dwc->residue -= dwc_get_sent(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + + dwc->residue -= desc->len; + list_for_each_entry(child, &desc->tx_list, desc_node) { + if (child->lli.llp == llp) { + /* Currently in progress */ + dwc->residue -= dwc_get_sent(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + return; + } + dwc->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); + + if (!list_empty(&dwc->queue)) { + list_move(dwc->queue.next, &dwc->active_list); + dwc_dostart(dwc, dwc_first_active(dwc)); + } + spin_unlock_irqrestore(&dwc->lock, flags); +} + +static inline void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli) +{ + dev_crit(chan2dev(&dwc->chan), " desc: s0x%x d0x%x l0x%x c0x%x:%x\n", + lli->sar, lli->dar, lli->llp, lli->ctlhi, lli->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->lli); + list_for_each_entry(child, &bad_desc->tx_list, desc_node) + dwc_dump_lli(dwc, &child->lli); + + spin_unlock_irqrestore(&dwc->lock, flags); + + /* Pretend the descriptor completed successfully */ + dwc_descriptor_complete(dwc, bad_desc, true); +} + +/* --------------------- Cyclic DMA API extensions -------------------- */ + +dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + return channel_readl(dwc, SAR); +} +EXPORT_SYMBOL(dw_dma_get_src_addr); + +dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + return channel_readl(dwc, DAR); +} +EXPORT_SYMBOL(dw_dma_get_dst_addr); + +/* Called with dwc->lock held and all DMAC interrupts disabled */ +static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc, + u32 status_err, u32 status_xfer) +{ + unsigned long flags; + + if (dwc->mask) { + void (*callback)(void *param); + void *callback_param; + + dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n", + channel_readl(dwc, LLP)); + + callback = dwc->cdesc->period_callback; + callback_param = dwc->cdesc->period_callback_param; + + if (callback) + callback(callback_param); + } + + /* + * Error and transfer complete are highly unlikely, and will most + * likely be due to a configuration error by the user. + */ + if (unlikely(status_err & dwc->mask) || + unlikely(status_xfer & dwc->mask)) { + int i; + + dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s " + "interrupt, stopping DMA transfer\n", + status_xfer ? "xfer" : "error"); + + spin_lock_irqsave(&dwc->lock, flags); + + dwc_dump_chan_regs(dwc); + + dwc_chan_disable(dw, dwc); + + /* Make sure DMA does not restart by loading a new list */ + channel_writel(dwc, LLP, 0); + channel_writel(dwc, CTL_LO, 0); + channel_writel(dwc, CTL_HI, 0); + + dma_writel(dw, CLEAR.ERROR, dwc->mask); + dma_writel(dw, CLEAR.XFER, dwc->mask); + + for (i = 0; i < dwc->cdesc->periods; i++) + dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli); + + spin_unlock_irqrestore(&dwc->lock, flags); + } +} + +/* ------------------------------------------------------------------------- */ + +static void dw_dma_tasklet(unsigned long data) +{ + struct dw_dma *dw = (struct dw_dma *)data; + struct dw_dma_chan *dwc; + u32 status_xfer; + u32 status_err; + 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)) + dwc_handle_cyclic(dw, dwc, status_err, status_xfer); + 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; + + dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, + dma_readl(dw, STATUS_INT)); + + /* + * 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.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.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 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. + */ + if (list_empty(&dwc->active_list)) { + dev_vdbg(chan2dev(tx->chan), "%s: started %u\n", __func__, + desc->txd.cookie); + list_add_tail(&desc->desc_node, &dwc->active_list); + dwc_dostart(dwc, dwc_first_active(dwc)); + } else { + dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, + desc->txd.cookie); + + list_add_tail(&desc->desc_node, &dwc->queue); + } + + spin_unlock_irqrestore(&dwc->lock, flags); + + return cookie; +} + +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; + unsigned int src_width; + unsigned int dst_width; + unsigned int data_width; + u32 ctllo; + + dev_vdbg(chan2dev(chan), + "%s: d0x%llx s0x%llx l0x%zx f0x%lx\n", __func__, + (unsigned long long)dest, (unsigned long long)src, + len, flags); + + if (unlikely(!len)) { + dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); + return NULL; + } + + dwc->direction = DMA_MEM_TO_MEM; + + data_width = min_t(unsigned int, dw->data_width[dwc->src_master], + dw->data_width[dwc->dst_master]); + + src_width = dst_width = min_t(unsigned int, data_width, + dwc_fast_fls(src | dest | len)); + + ctllo = DWC_DEFAULT_CTLLO(chan) + | 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 << src_width) { + xfer_count = min_t(size_t, (len - offset) >> src_width, + dwc->block_size); + + desc = dwc_desc_get(dwc); + if (!desc) + goto err_desc_get; + + desc->lli.sar = src + offset; + desc->lli.dar = dest + offset; + desc->lli.ctllo = ctllo; + desc->lli.ctlhi = xfer_count; + desc->len = xfer_count << src_width; + + if (!first) { + first = desc; + } else { + prev->lli.llp = desc->txd.phys; + list_add_tail(&desc->desc_node, + &first->tx_list); + } + prev = desc; + } + + if (flags & DMA_PREP_INTERRUPT) + /* Trigger interrupt after last block */ + prev->lli.ctllo |= DWC_CTLL_INT_EN; + + prev->lli.llp = 0; + 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; + dma_addr_t reg; + unsigned int reg_width; + unsigned int mem_width; + unsigned int data_width; + 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 = __fls(sconfig->dst_addr_width); + reg = sconfig->dst_addr; + ctllo = (DWC_DEFAULT_CTLLO(chan) + | 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); + + data_width = dw->data_width[dwc->src_master]; + + for_each_sg(sgl, sg, sg_len, i) { + struct dw_desc *desc; + u32 len, dlen, mem; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + + mem_width = min_t(unsigned int, + data_width, dwc_fast_fls(mem | len)); + +slave_sg_todev_fill_desc: + desc = dwc_desc_get(dwc); + if (!desc) { + dev_err(chan2dev(chan), + "not enough descriptors available\n"); + goto err_desc_get; + } + + desc->lli.sar = mem; + desc->lli.dar = reg; + desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width); + if ((len >> mem_width) > dwc->block_size) { + dlen = dwc->block_size << mem_width; + mem += dlen; + len -= dlen; + } else { + dlen = len; + len = 0; + } + + desc->lli.ctlhi = dlen >> mem_width; + desc->len = dlen; + + if (!first) { + first = desc; + } else { + prev->lli.llp = desc->txd.phys; + list_add_tail(&desc->desc_node, + &first->tx_list); + } + prev = desc; + total_len += dlen; + + if (len) + goto slave_sg_todev_fill_desc; + } + break; + case DMA_DEV_TO_MEM: + reg_width = __fls(sconfig->src_addr_width); + reg = sconfig->src_addr; + ctllo = (DWC_DEFAULT_CTLLO(chan) + | 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); + + data_width = dw->data_width[dwc->dst_master]; + + for_each_sg(sgl, sg, sg_len, i) { + struct dw_desc *desc; + u32 len, dlen, mem; + + mem = sg_dma_address(sg); + len = sg_dma_len(sg); + + mem_width = min_t(unsigned int, + data_width, dwc_fast_fls(mem | len)); + +slave_sg_fromdev_fill_desc: + desc = dwc_desc_get(dwc); + if (!desc) { + dev_err(chan2dev(chan), + "not enough descriptors available\n"); + goto err_desc_get; + } + + desc->lli.sar = reg; + desc->lli.dar = mem; + desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width); + if ((len >> reg_width) > dwc->block_size) { + dlen = dwc->block_size << reg_width; + mem += dlen; + len -= dlen; + } else { + dlen = len; + len = 0; + } + desc->lli.ctlhi = dlen >> reg_width; + desc->len = dlen; + + if (!first) { + first = desc; + } else { + prev->lli.llp = desc->txd.phys; + list_add_tail(&desc->desc_node, + &first->tx_list); + } + prev = desc; + 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 */ + prev->lli.ctllo |= DWC_CTLL_INT_EN; + + prev->lli.llp = 0; + first->total_len = total_len; + + return &first->txd; + +err_desc_get: + dwc_desc_put(dwc, first); + return NULL; +} + +/* + * Fix sconfig's burst size according to dw_dmac. We need to convert them as: + * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3. + * + * NOTE: burst size 2 is not supported by controller. + * + * This can be done by finding least significant bit set: n & (n - 1) + */ +static inline void convert_burst(u32 *maxburst) +{ + if (*maxburst > 1) + *maxburst = fls(*maxburst) - 2; + else + *maxburst = 0; +} + +static int +set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + + /* Check if chan will be configured for slave transfers */ + if (!is_slave_direction(sconfig->direction)) + return -EINVAL; + + memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig)); + dwc->direction = sconfig->direction; + + /* Take the request line from slave_id member */ + if (dwc->request_line == ~0) + dwc->request_line = sconfig->slave_id; + + convert_burst(&dwc->dma_sconfig.src_maxburst); + convert_burst(&dwc->dma_sconfig.dst_maxburst); + + return 0; +} + +static inline void dwc_chan_pause(struct dw_dma_chan *dwc) +{ + u32 cfglo = channel_readl(dwc, CFG_LO); + unsigned int count = 20; /* timeout iterations */ + + channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP); + while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--) + udelay(2); + + dwc->paused = true; +} + +static inline void dwc_chan_resume(struct dw_dma_chan *dwc) +{ + u32 cfglo = channel_readl(dwc, CFG_LO); + + channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP); + + dwc->paused = false; +} + +static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, + unsigned long arg) +{ + 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); + + if (cmd == DMA_PAUSE) { + spin_lock_irqsave(&dwc->lock, flags); + + dwc_chan_pause(dwc); + + spin_unlock_irqrestore(&dwc->lock, flags); + } else if (cmd == DMA_RESUME) { + if (!dwc->paused) + return 0; + + spin_lock_irqsave(&dwc->lock, flags); + + dwc_chan_resume(dwc); + + spin_unlock_irqrestore(&dwc->lock, flags); + } else if (cmd == DMA_TERMINATE_ALL) { + spin_lock_irqsave(&dwc->lock, flags); + + clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags); + + dwc_chan_disable(dw, dwc); + + dwc_chan_resume(dwc); + + /* 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); + } else if (cmd == DMA_SLAVE_CONFIG) { + return set_runtime_config(chan, (struct dma_slave_config *)arg); + } else { + return -ENXIO; + } + + return 0; +} + +static inline u32 dwc_get_residue(struct dw_dma_chan *dwc) +{ + unsigned long flags; + u32 residue; + + spin_lock_irqsave(&dwc->lock, flags); + + residue = dwc->residue; + if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue) + residue -= dwc_get_sent(dwc); + + 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_SUCCESS) { + dwc_scan_descriptors(to_dw_dma(chan->device), dwc); + + ret = dma_cookie_status(chan, cookie, txstate); + } + + if (ret != DMA_SUCCESS) + dma_set_residue(txstate, dwc_get_residue(dwc)); + + if (dwc->paused) + return DMA_PAUSED; + + return ret; +} + +static void dwc_issue_pending(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + + if (!list_empty(&dwc->queue)) + dwc_scan_descriptors(to_dw_dma(chan->device), dwc); +} + +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); + struct dw_desc *desc; + int i; + unsigned long flags; + + 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. + */ + + dwc_set_masters(dwc); + + spin_lock_irqsave(&dwc->lock, flags); + i = dwc->descs_allocated; + while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) { + dma_addr_t phys; + + spin_unlock_irqrestore(&dwc->lock, flags); + + desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys); + if (!desc) + goto err_desc_alloc; + + memset(desc, 0, sizeof(struct dw_desc)); + + INIT_LIST_HEAD(&desc->tx_list); + dma_async_tx_descriptor_init(&desc->txd, chan); + desc->txd.tx_submit = dwc_tx_submit; + desc->txd.flags = DMA_CTRL_ACK; + desc->txd.phys = phys; + + dwc_desc_put(dwc, desc); + + spin_lock_irqsave(&dwc->lock, flags); + i = ++dwc->descs_allocated; + } + + spin_unlock_irqrestore(&dwc->lock, flags); + + dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i); + + return i; + +err_desc_alloc: + dev_info(chan2dev(chan), "only allocated %d descriptors\n", i); + + return i; +} + +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); + struct dw_desc *desc, *_desc; + unsigned long flags; + LIST_HEAD(list); + + 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); |