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core.c
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/*
* 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/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 driver has been tested with the Atmel AT32AP7000, which does not
* support descriptor writeback.
*/
#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; \
u8 _dms = (_dwc->direction == DMA_MEM_TO_DEV) ? \
_dwc->dws.p_master : _dwc->dws.m_master; \
u8 _sms = (_dwc->direction == DMA_DEV_TO_MEM) ? \
_dwc->dws.p_master : _dwc->dws.m_master; \
\
(DWC_CTLL_DST_MSIZE(_dmsize) \
| DWC_CTLL_SRC_MSIZE(_smsize) \
| DWC_CTLL_LLP_D_EN \
| DWC_CTLL_LLP_S_EN \
| DWC_CTLL_DMS(_dms) \
| DWC_CTLL_SMS(_sms)); \
})
/* 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_chan_idma32(struct dw_dma_chan *dwc)
{
u32 cfghi = 0;
u32 cfglo = 0;
/* Set default burst alignment */
cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
/* Low 4 bits of the request lines */
cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
/* Request line extension (2 bits) */
cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);
}
static void dwc_initialize_chan_dw(struct dw_dma_chan *dwc)
{
u32 cfghi = DWC_CFGH_FIFO_MODE;
u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
bool hs_polarity = dwc->dws.hs_polarity;
cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
/* Set polarity of handshake interface */
cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);
}
static void dwc_initialize(struct dw_dma_chan *dwc)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
return;
if (dw->pdata->is_idma32)
dwc_initialize_chan_idma32(dwc);
else
dwc_initialize_chan_dw(dwc);
/* Enable interrupts */
channel_set_bit(dw, MASK.XFER, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask);
set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
}
/*----------------------------------------------------------------------*/
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();
}
static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
unsigned int width, size_t *len)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
u32 block;
/* Always in bytes for iDMA 32-bit */
if (dw->pdata->is_idma32)
width = 0;
if ((bytes >> width) > dwc->block_size) {
block = dwc->block_size;
*len = block << width;
} else {
block = bytes >> width;
*len = bytes;
}
return block;
}
static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
{
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
if (dw->pdata->is_idma32)
return IDMA32C_CTLH_BLOCK_TS(block);
return DWC_CTLH_BLOCK_TS(block) << width;
}
/*----------------------------------------------------------------------*/
/* 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)
{
u32 ctlhi = channel_readl(dwc, CTL_HI);
u32 ctllo = channel_readl(dwc, CTL_LO);
return 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(unsigned long data)
{
struct dw_dma *dw = (struct dw_dma *)data;
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;
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 = 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) {
desc = dwc_desc_get(dwc);
if (!desc)
goto err_desc_get;
lli_write(desc, sar, src + offset);
lli_write(desc, dar, dest + offset);
lli_write(desc, ctllo, ctllo);
lli_write(desc, ctlhi, bytes2block(dwc, len - offset, src_width, &xfer_count));
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;
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 = (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);
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;
lli_write(desc, sar, mem);
lli_write(desc, dar, reg);
lli_write(desc, ctlhi, bytes2block(dwc, len, mem_width, &dlen));
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 = (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);
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;
lli_write(desc, sar, reg);
lli_write(desc, dar, mem);
lli_write(desc, ctlhi, bytes2block(dwc, len, reg_width, &dlen));
mem_width = __ffs(data_width | mem | dlen);
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;
/* 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 dma_slave_config *sc = &dwc->dma_sconfig;
struct dw_dma *dw = to_dw_dma(chan->device);
/*
* 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 DesignWare controller.
* iDMA 32-bit supports it.
*/
u32 s = dw->pdata->is_idma32 ? 1 : 2;
/* 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;
sc->src_maxburst = sc->src_maxburst > 1 ? fls(sc->src_maxburst) - s : 0;
sc->dst_maxburst = sc->dst_maxburst > 1 ? fls(sc->dst_maxburst) - s : 0;
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 */
u32 cfglo;
cfglo = channel_readl(dwc, CFG_LO);
if (dw->pdata->is_idma32) {
if (drain)
cfglo |= IDMA32C_CFGL_CH_DRAIN;
else
cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
}
channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
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)
{
u32 cfglo = channel_readl(dwc, CFG_LO);
channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
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);
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);
/* 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(struct dw_dma_chan *dwc, dma_cookie_t cookie)