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linux/drivers/dma/dw_dmac.c
Linus Walleij 058276303d DMAENGINE: extend the control command to include an arg 
This adds an argument to the DMAengine control function, so that
we can later provide control commands that need some external data
passed in through an argument akin to the ioctl() operation
prototype.

[dan.j.williams@intel.com: fix up some missed conversions]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-17 16:30:42 -07:00

1461 lines
37 KiB
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/*
* Driver for the Synopsys DesignWare DMA Controller (aka DMACA on
* AVR32 systems.)
*
* Copyright (C) 2007-2008 Atmel 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/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "dw_dmac_regs.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.
*/
/* NOTE: DMS+SMS is system-specific. We should get this information
* from the platform code somehow.
*/
#define DWC_DEFAULT_CTLLO (DWC_CTLL_DST_MSIZE(0) \
| DWC_CTLL_SRC_MSIZE(0) \
| DWC_CTLL_DMS(0) \
| DWC_CTLL_SMS(1) \
| DWC_CTLL_LLP_D_EN \
| DWC_CTLL_LLP_S_EN)
/*
* This is configuration-dependent and usually a funny size like 4095.
* Let's round it down to the nearest power of two.
*
* Note that this is a transfer count, i.e. if we transfer 32-bit
* words, we can do 8192 bytes per descriptor.
*
* This parameter is also system-specific.
*/
#define DWC_MAX_COUNT 2048U
/*
* 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
/*----------------------------------------------------------------------*/
/*
* Because we're not relying on writeback from the controller (it may not
* even be configured into the core!) we don't need to use dma_pool. These
* descriptors -- and associated data -- are cacheable. We do need to make
* sure their dcache entries are written back before handing them off to
* the controller, though.
*/
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 list_entry(dwc->active_list.next, struct dw_desc, desc_node);
}
static struct dw_desc *dwc_first_queued(struct dw_dma_chan *dwc)
{
return list_entry(dwc->queue.next, struct dw_desc, desc_node);
}
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;
spin_lock_bh(&dwc->lock);
list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
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);
i++;
}
spin_unlock_bh(&dwc->lock);
dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
return ret;
}
static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
{
struct dw_desc *child;
list_for_each_entry(child, &desc->tx_list, desc_node)
dma_sync_single_for_cpu(chan2parent(&dwc->chan),
child->txd.phys, sizeof(child->lli),
DMA_TO_DEVICE);
dma_sync_single_for_cpu(chan2parent(&dwc->chan),
desc->txd.phys, sizeof(desc->lli),
DMA_TO_DEVICE);
}
/*
* 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)
{
if (desc) {
struct dw_desc *child;
dwc_sync_desc_for_cpu(dwc, desc);
spin_lock_bh(&dwc->lock);
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_bh(&dwc->lock);
}
}
/* Called with dwc->lock held and bh disabled */
static dma_cookie_t
dwc_assign_cookie(struct dw_dma_chan *dwc, struct dw_desc *desc)
{
dma_cookie_t cookie = dwc->chan.cookie;
if (++cookie < 0)
cookie = 1;
dwc->chan.cookie = cookie;
desc->txd.cookie = cookie;
return cookie;
}
/*----------------------------------------------------------------------*/
/* 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);
/* 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");
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));
/* The tasklet will hopefully advance the queue... */
return;
}
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)
{
dma_async_tx_callback callback;
void *param;
struct dma_async_tx_descriptor *txd = &desc->txd;
dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
dwc->completed = txd->cookie;
callback = txd->callback;
param = txd->callback_param;
dwc_sync_desc_for_cpu(dwc, desc);
list_splice_init(&desc->tx_list, &dwc->free_list);
list_move(&desc->desc_node, &dwc->free_list);
if (!dwc->chan.private) {
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->len, DMA_FROM_DEVICE);
else
dma_unmap_page(parent, desc->lli.dar,
desc->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->len, DMA_TO_DEVICE);
else
dma_unmap_page(parent, desc->lli.sar,
desc->len, DMA_TO_DEVICE);
}
}
/*
* The API requires that no submissions are done from a
* callback, so we don't need to drop the lock here
*/
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);
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... */
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
}
/*
* Submit queued descriptors ASAP, i.e. before we go through
* the completed ones.
*/
if (!list_empty(&dwc->queue))
dwc_dostart(dwc, dwc_first_queued(dwc));
list_splice_init(&dwc->active_list, &list);
list_splice_init(&dwc->queue, &dwc->active_list);
list_for_each_entry_safe(desc, _desc, &list, desc_node)
dwc_descriptor_complete(dwc, desc);
}
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;
/*
* Clear block interrupt flag before scanning so that we don't
* miss any, and read LLP before RAW_XFER to ensure it is
* valid if we decide to scan the list.
*/
dma_writel(dw, CLEAR.BLOCK, dwc->mask);
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);
dwc_complete_all(dw, dwc);
return;
}
dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
if (desc->lli.llp == llp)
/* This one is currently in progress */
return;
list_for_each_entry(child, &desc->tx_list, desc_node)
if (child->lli.llp == llp)
/* Currently in progress */
return;
/*
* No descriptors so far seem to be in progress, i.e.
* this one must be done.
*/
dwc_descriptor_complete(dwc, desc);
}
dev_err(chan2dev(&dwc->chan),
"BUG: All descriptors done, but channel not idle!\n");
/* Try to continue after resetting the channel... */
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
if (!list_empty(&dwc->queue)) {
dwc_dostart(dwc, dwc_first_queued(dwc));
list_splice_init(&dwc->queue, &dwc->active_list);
}
}
static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
{
dev_printk(KERN_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;
dwc_scan_descriptors(dw, dwc);
/*
* 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_splice_init(&dwc->queue, 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));
/*
* 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_printk(KERN_CRIT, chan2dev(&dwc->chan),
"Bad descriptor submitted for DMA!\n");
dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
" 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);
/* Pretend the descriptor completed successfully */
dwc_descriptor_complete(dwc, bad_desc);
}
/* --------------------- Cyclic DMA API extensions -------------------- */
inline 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);
inline 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_block, u32 status_err, u32 status_xfer)
{
if (status_block & 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));
dma_writel(dw, CLEAR.BLOCK, dwc->mask);
callback = dwc->cdesc->period_callback;
callback_param = dwc->cdesc->period_callback_param;
if (callback) {
spin_unlock(&dwc->lock);
callback(callback_param);
spin_lock(&dwc->lock);
}
}
/*
* 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");
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));
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
/* 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.BLOCK, dwc->mask);
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);
}
}
/* ------------------------------------------------------------------------- */
static void dw_dma_tasklet(unsigned long data)
{
struct dw_dma *dw = (struct dw_dma *)data;
struct dw_dma_chan *dwc;
u32 status_block;
u32 status_xfer;
u32 status_err;
int i;
status_block = dma_readl(dw, RAW.BLOCK);
status_xfer = dma_readl(dw, RAW.XFER);
status_err = dma_readl(dw, RAW.ERROR);
dev_vdbg(dw->dma.dev, "tasklet: status_block=%x status_err=%x\n",
status_block, status_err);
for (i = 0; i < dw->dma.chancnt; i++) {
dwc = &dw->chan[i];
spin_lock(&dwc->lock);
if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
dwc_handle_cyclic(dw, dwc, status_block, status_err,
status_xfer);
else if (status_err & (1 << i))
dwc_handle_error(dw, dwc);
else if ((status_block | status_xfer) & (1 << i))
dwc_scan_descriptors(dw, dwc);
spin_unlock(&dwc->lock);
}
/*
* Re-enable interrupts. Block Complete interrupts are only
* enabled if the INT_EN bit in the descriptor is set. This
* will trigger a scan before the whole list is done.
*/
channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
channel_set_bit(dw, MASK.BLOCK, 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, "interrupt: status=0x%x\n",
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.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 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;
spin_lock_bh(&dwc->lock);
cookie = dwc_assign_cookie(dwc, desc);
/*
* 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), "tx_submit: started %u\n",
desc->txd.cookie);
dwc_dostart(dwc, desc);
list_add_tail(&desc->desc_node, &dwc->active_list);
} else {
dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
desc->txd.cookie);
list_add_tail(&desc->desc_node, &dwc->queue);
}
spin_unlock_bh(&dwc->lock);
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_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;
u32 ctllo;
dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
dest, src, len, flags);
if (unlikely(!len)) {
dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
return NULL;
}
/*
* We can be a lot more clever here, but this should take care
* of the most common optimization.
*/
if (!((src | dest | len) & 3))
src_width = dst_width = 2;
else if (!((src | dest | len) & 1))
src_width = dst_width = 1;
else
src_width = dst_width = 0;
ctllo = DWC_DEFAULT_CTLLO
| 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_MAX_COUNT);
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;
if (!first) {
first = desc;
} else {
prev->lli.llp = desc->txd.phys;
dma_sync_single_for_device(chan2parent(chan),
prev->txd.phys, sizeof(prev->lli),
DMA_TO_DEVICE);
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;
dma_sync_single_for_device(chan2parent(chan),
prev->txd.phys, sizeof(prev->lli),
DMA_TO_DEVICE);
first->txd.flags = flags;
first->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_data_direction direction,
unsigned long flags)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma_slave *dws = chan->private;
struct dw_desc *prev;
struct dw_desc *first;
u32 ctllo;
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_dma_slave\n");
if (unlikely(!dws || !sg_len))
return NULL;
reg_width = dws->reg_width;
prev = first = NULL;
switch (direction) {
case DMA_TO_DEVICE:
ctllo = (DWC_DEFAULT_CTLLO
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_DST_FIX
| DWC_CTLL_SRC_INC
| DWC_CTLL_FC_M2P);
reg = dws->tx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len;
u32 mem;
desc = dwc_desc_get(dwc);
if (!desc) {
dev_err(chan2dev(chan),
"not enough descriptors available\n");
goto err_desc_get;
}
mem = sg_phys(sg);
len = sg_dma_len(sg);
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
desc->lli.sar = mem;
desc->lli.dar = reg;
desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width);
desc->lli.ctlhi = len >> mem_width;
if (!first) {
first = desc;
} else {
prev->lli.llp = desc->txd.phys;
dma_sync_single_for_device(chan2parent(chan),
prev->txd.phys,
sizeof(prev->lli),
DMA_TO_DEVICE);
list_add_tail(&desc->desc_node,
&first->tx_list);
}
prev = desc;
total_len += len;
}
break;
case DMA_FROM_DEVICE:
ctllo = (DWC_DEFAULT_CTLLO
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_INC
| DWC_CTLL_SRC_FIX
| DWC_CTLL_FC_P2M);
reg = dws->rx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len;
u32 mem;
desc = dwc_desc_get(dwc);
if (!desc) {
dev_err(chan2dev(chan),
"not enough descriptors available\n");
goto err_desc_get;
}
mem = sg_phys(sg);
len = sg_dma_len(sg);
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
desc->lli.sar = reg;
desc->lli.dar = mem;
desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width);
desc->lli.ctlhi = len >> reg_width;
if (!first) {
first = desc;
} else {
prev->lli.llp = desc->txd.phys;
dma_sync_single_for_device(chan2parent(chan),
prev->txd.phys,
sizeof(prev->lli),
DMA_TO_DEVICE);
list_add_tail(&desc->desc_node,
&first->tx_list);
}
prev = desc;
total_len += len;
}
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;
dma_sync_single_for_device(chan2parent(chan),
prev->txd.phys, sizeof(prev->lli),
DMA_TO_DEVICE);
first->len = total_len;
return &first->txd;
err_desc_get:
dwc_desc_put(dwc, first);
return NULL;
}
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;
LIST_HEAD(list);
/* Only supports DMA_TERMINATE_ALL */
if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
/*
* 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_bh(&dwc->lock);
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
/* active_list entries will end up before queued entries */
list_splice_init(&dwc->queue, &list);
list_splice_init(&dwc->active_list, &list);
spin_unlock_bh(&dwc->lock);
/* Flush all pending and queued descriptors */
list_for_each_entry_safe(desc, _desc, &list, desc_node)
dwc_descriptor_complete(dwc, desc);
return 0;
}
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);
dma_cookie_t last_used;
dma_cookie_t last_complete;
int ret;
last_complete = dwc->completed;
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, last_complete, last_used);
if (ret != DMA_SUCCESS) {
dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
last_complete = dwc->completed;
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, last_complete, last_used);
}
dma_set_tx_state(txstate, last_complete, last_used, 0);
return ret;
}
static void dwc_issue_pending(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
spin_lock_bh(&dwc->lock);
if (!list_empty(&dwc->queue))
dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
spin_unlock_bh(&dwc->lock);
}
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;
struct dw_dma_slave *dws;
int i;
u32 cfghi;
u32 cfglo;
dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
/* ASSERT: channel is idle */
if (dma_readl(dw, CH_EN) & dwc->mask) {
dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
return -EIO;
}
dwc->completed = chan->cookie = 1;
cfghi = DWC_CFGH_FIFO_MODE;
cfglo = 0;
dws = chan->private;
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;
}
channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);
/*
* 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.
*/
spin_lock_bh(&dwc->lock);
i = dwc->descs_allocated;
while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
spin_unlock_bh(&dwc->lock);
desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
if (!desc) {
dev_info(chan2dev(chan),
"only allocated %d descriptors\n", i);
spin_lock_bh(&dwc->lock);
break;
}
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 = dma_map_single(chan2parent(chan), &desc->lli,
sizeof(desc->lli), DMA_TO_DEVICE);
dwc_desc_put(dwc, desc);
spin_lock_bh(&dwc->lock);
i = ++dwc->descs_allocated;
}
/* Enable interrupts */
channel_set_bit(dw, MASK.XFER, dwc->mask);
channel_set_bit(dw, MASK.BLOCK, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask);
spin_unlock_bh(&dwc->lock);
dev_dbg(chan2dev(chan),
"alloc_chan_resources 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;
LIST_HEAD(list);
dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
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_bh(&dwc->lock);
list_splice_init(&dwc->free_list, &list);
dwc->descs_allocated = 0;
/* 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_bh(&dwc->lock);
list_for_each_entry_safe(desc, _desc, &list, desc_node) {
dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
dma_unmap_single(chan2parent(chan), desc->txd.phys,
sizeof(desc->lli), DMA_TO_DEVICE);
kfree(desc);
}
dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
}
/* --------------------- Cyclic DMA API extensions -------------------- */
/**
* dw_dma_cyclic_start - start the cyclic DMA transfer
* @chan: the DMA channel to start
*
* Must be called with soft interrupts disabled. Returns zero on success or
* -errno on failure.
*/
int dw_dma_cyclic_start(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
return -ENODEV;
}
spin_lock(&dwc->lock);
/* 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");
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));
spin_unlock(&dwc->lock);
return -EBUSY;
}
dma_writel(dw, CLEAR.BLOCK, dwc->mask);
dma_writel(dw, CLEAR.ERROR, dwc->mask);
dma_writel(dw, CLEAR.XFER, dwc->mask);
/* setup DMAC channel registers */
channel_writel(dwc, LLP, dwc->cdesc->desc[0]->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);
spin_unlock(&dwc->lock);
return 0;
}
EXPORT_SYMBOL(dw_dma_cyclic_start);
/**
* dw_dma_cyclic_stop - stop the cyclic DMA transfer
* @chan: the DMA channel to stop
*
* Must be called with soft interrupts disabled.
*/
void dw_dma_cyclic_stop(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
spin_lock(&dwc->lock);
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
spin_unlock(&dwc->lock);
}
EXPORT_SYMBOL(dw_dma_cyclic_stop);
/**
* dw_dma_cyclic_prep - 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
*
* Must be called before trying to start the transfer. Returns a valid struct
* dw_cyclic_desc if successful or an ERR_PTR(-errno) if not successful.
*/
struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
dma_addr_t buf_addr, size_t buf_len, size_t period_len,
enum dma_data_direction direction)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_cyclic_desc *cdesc;
struct dw_cyclic_desc *retval = NULL;
struct dw_desc *desc;
struct dw_desc *last = NULL;
struct dw_dma_slave *dws = chan->private;
unsigned long was_cyclic;
unsigned int reg_width;
unsigned int periods;
unsigned int i;
spin_lock_bh(&dwc->lock);
if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
spin_unlock_bh(&dwc->lock);
dev_dbg(chan2dev(&dwc->chan),
"queue and/or active list are not empty\n");
return ERR_PTR(-EBUSY);
}
was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
spin_unlock_bh(&dwc->lock);
if (was_cyclic) {
dev_dbg(chan2dev(&dwc->chan),
"channel already prepared for cyclic DMA\n");
return ERR_PTR(-EBUSY);
}
retval = ERR_PTR(-EINVAL);
reg_width = dws->reg_width;
periods = buf_len / period_len;
/* Check for too big/unaligned periods and unaligned DMA buffer. */
if (period_len > (DWC_MAX_COUNT << reg_width))
goto out_err;
if (unlikely(period_len & ((1 << reg_width) - 1)))
goto out_err;
if (unlikely(buf_addr & ((1 << reg_width) - 1)))
goto out_err;
if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
goto out_err;
retval = ERR_PTR(-ENOMEM);
if (periods > NR_DESCS_PER_CHANNEL)
goto out_err;
cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL);
if (!cdesc)
goto out_err;
cdesc->desc = kzalloc(sizeof(struct dw_desc *) * periods, GFP_KERNEL);
if (!cdesc->desc)
goto out_err_alloc;
for (i = 0; i < periods; i++) {
desc = dwc_desc_get(dwc);
if (!desc)
goto out_err_desc_get;
switch (direction) {
case DMA_TO_DEVICE:
desc->lli.dar = dws->tx_reg;
desc->lli.sar = buf_addr + (period_len * i);
desc->lli.ctllo = (DWC_DEFAULT_CTLLO
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_FIX
| DWC_CTLL_SRC_INC
| DWC_CTLL_FC_M2P
| DWC_CTLL_INT_EN);
break;
case DMA_FROM_DEVICE:
desc->lli.dar = buf_addr + (period_len * i);
desc->lli.sar = dws->rx_reg;
desc->lli.ctllo = (DWC_DEFAULT_CTLLO
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_DST_INC
| DWC_CTLL_SRC_FIX
| DWC_CTLL_FC_P2M
| DWC_CTLL_INT_EN);
break;
default:
break;
}
desc->lli.ctlhi = (period_len >> reg_width);
cdesc->desc[i] = desc;
if (last) {
last->lli.llp = desc->txd.phys;
dma_sync_single_for_device(chan2parent(chan),
last->txd.phys, sizeof(last->lli),
DMA_TO_DEVICE);
}
last = desc;
}
/* lets make a cyclic list */
last->lli.llp = cdesc->desc[0]->txd.phys;
dma_sync_single_for_device(chan2parent(chan), last->txd.phys,
sizeof(last->lli), DMA_TO_DEVICE);
dev_dbg(chan2dev(&dwc->chan), "cyclic prepared buf 0x%08x len %zu "
"period %zu periods %d\n", buf_addr, buf_len,
period_len, periods);
cdesc->periods = periods;
dwc->cdesc = cdesc;
return cdesc;
out_err_desc_get:
while (i--)
dwc_desc_put(dwc, cdesc->desc[i]);
out_err_alloc:
kfree(cdesc);
out_err:
clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
return (struct dw_cyclic_desc *)retval;
}
EXPORT_SYMBOL(dw_dma_cyclic_prep);
/**
* dw_dma_cyclic_free - free a prepared cyclic DMA transfer
* @chan: the DMA channel to free
*/
void dw_dma_cyclic_free(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
struct dw_cyclic_desc *cdesc = dwc->cdesc;
int i;
dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
if (!cdesc)
return;
spin_lock_bh(&dwc->lock);
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
dma_writel(dw, CLEAR.BLOCK, dwc->mask);
dma_writel(dw, CLEAR.ERROR, dwc->mask);
dma_writel(dw, CLEAR.XFER, dwc->mask);
spin_unlock_bh(&dwc->lock);
for (i = 0; i < cdesc->periods; i++)
dwc_desc_put(dwc, cdesc->desc[i]);
kfree(cdesc->desc);
kfree(cdesc);
clear_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
}
EXPORT_SYMBOL(dw_dma_cyclic_free);
/*----------------------------------------------------------------------*/
static void 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();
}
static int __init dw_probe(struct platform_device *pdev)
{
struct dw_dma_platform_data *pdata;
struct resource *io;
struct dw_dma *dw;
size_t size;
int irq;
int err;
int i;
pdata = pdev->dev.platform_data;
if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
return -EINVAL;
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!io)
return -EINVAL;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
size = sizeof(struct dw_dma);
size += pdata->nr_channels * sizeof(struct dw_dma_chan);
dw = kzalloc(size, GFP_KERNEL);
if (!dw)
return -ENOMEM;
if (!request_mem_region(io->start, DW_REGLEN, pdev->dev.driver->name)) {
err = -EBUSY;
goto err_kfree;
}
dw->regs = ioremap(io->start, DW_REGLEN);
if (!dw->regs) {
err = -ENOMEM;
goto err_release_r;
}
dw->clk = clk_get(&pdev->dev, "hclk");
if (IS_ERR(dw->clk)) {
err = PTR_ERR(dw->clk);
goto err_clk;
}
clk_enable(dw->clk);
/* force dma off, just in case */
dw_dma_off(dw);
err = request_irq(irq, dw_dma_interrupt, 0, "dw_dmac", dw);
if (err)
goto err_irq;
platform_set_drvdata(pdev, dw);
tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
INIT_LIST_HEAD(&dw->dma.channels);
for (i = 0; i < pdata->nr_channels; i++, dw->dma.chancnt++) {
struct dw_dma_chan *dwc = &dw->chan[i];
dwc->chan.device = &dw->dma;
dwc->chan.cookie = dwc->completed = 1;
dwc->chan.chan_id = i;
list_add_tail(&dwc->chan.device_node, &dw->dma.channels);
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);
INIT_LIST_HEAD(&dwc->free_list);
channel_clear_bit(dw, CH_EN, dwc->mask);
}
/* Clear/disable 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);
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);
dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
dw->dma.dev = &pdev->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_control = dwc_control;
dw->dma.device_tx_status = dwc_tx_status;
dw->dma.device_issue_pending = dwc_issue_pending;
dma_writel(dw, CFG, DW_CFG_DMA_EN);
printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n",
dev_name(&pdev->dev), dw->dma.chancnt);
dma_async_device_register(&dw->dma);
return 0;
err_irq:
clk_disable(dw->clk);
clk_put(dw->clk);
err_clk:
iounmap(dw->regs);
dw->regs = NULL;
err_release_r:
release_resource(io);
err_kfree:
kfree(dw);
return err;
}
static int __exit dw_remove(struct platform_device *pdev)
{
struct dw_dma *dw = platform_get_drvdata(pdev);
struct dw_dma_chan *dwc, *_dwc;
struct resource *io;
dw_dma_off(dw);
dma_async_device_unregister(&dw->dma);
free_irq(platform_get_irq(pdev, 0), 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);
}
clk_disable(dw->clk);
clk_put(dw->clk);
iounmap(dw->regs);
dw->regs = NULL;
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(io->start, DW_REGLEN);
kfree(dw);
return 0;
}
static void dw_shutdown(struct platform_device *pdev)
{
struct dw_dma *dw = platform_get_drvdata(pdev);
dw_dma_off(platform_get_drvdata(pdev));
clk_disable(dw->clk);
}
static int dw_suspend_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct dw_dma *dw = platform_get_drvdata(pdev);
dw_dma_off(platform_get_drvdata(pdev));
clk_disable(dw->clk);
return 0;
}
static int dw_resume_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct dw_dma *dw = platform_get_drvdata(pdev);
clk_enable(dw->clk);
dma_writel(dw, CFG, DW_CFG_DMA_EN);
return 0;
}
static const struct dev_pm_ops dw_dev_pm_ops = {
.suspend_noirq = dw_suspend_noirq,
.resume_noirq = dw_resume_noirq,
};
static struct platform_driver dw_driver = {
.remove = __exit_p(dw_remove),
.shutdown = dw_shutdown,
.driver = {
.name = "dw_dmac",
.pm = &dw_dev_pm_ops,
},
};
static int __init dw_init(void)
{
return platform_driver_probe(&dw_driver, dw_probe);
}
module_init(dw_init);
static void __exit dw_exit(void)
{
platform_driver_unregister(&dw_driver);
}
module_exit(dw_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller driver");
MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
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