Permalink
Switch branches/tags
Nothing to show
Find file
Fetching contributors…
Cannot retrieve contributors at this time
1442 lines (1166 sloc) 36.5 KB
/*
* Renesas SuperH DMA Engine support
*
* base is drivers/dma/flsdma.c
*
* Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
* Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
* Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* - DMA of SuperH does not have Hardware DMA chain mode.
* - MAX DMA size is 16MB.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/notifier.h>
#include <linux/kdebug.h>
#include <linux/spinlock.h>
#include <linux/rculist.h>
#include "shdma.h"
/* DMA descriptor control */
enum sh_dmae_desc_status {
DESC_IDLE,
DESC_PREPARED,
DESC_SUBMITTED,
DESC_COMPLETED, /* completed, have to call callback */
DESC_WAITING, /* callback called, waiting for ack / re-submit */
};
#define NR_DESCS_PER_CHANNEL 32
/* Default MEMCPY transfer size = 2^2 = 4 bytes */
#define LOG2_DEFAULT_XFER_SIZE 2
/*
* Used for write-side mutual exclusion for the global device list,
* read-side synchronization by way of RCU, and per-controller data.
*/
static DEFINE_SPINLOCK(sh_dmae_lock);
static LIST_HEAD(sh_dmae_devices);
/* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
{
__raw_writel(data, sh_dc->base + reg / sizeof(u32));
}
static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
{
return __raw_readl(sh_dc->base + reg / sizeof(u32));
}
static u16 dmaor_read(struct sh_dmae_device *shdev)
{
return __raw_readw(shdev->chan_reg + DMAOR / sizeof(u32));
}
static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
{
__raw_writew(data, shdev->chan_reg + DMAOR / sizeof(u32));
}
/*
* Reset DMA controller
*
* SH7780 has two DMAOR register
*/
static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
{
unsigned short dmaor;
unsigned long flags;
spin_lock_irqsave(&sh_dmae_lock, flags);
dmaor = dmaor_read(shdev);
dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
spin_unlock_irqrestore(&sh_dmae_lock, flags);
}
static int sh_dmae_rst(struct sh_dmae_device *shdev)
{
unsigned short dmaor;
unsigned long flags;
spin_lock_irqsave(&sh_dmae_lock, flags);
dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME);
dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init);
dmaor = dmaor_read(shdev);
spin_unlock_irqrestore(&sh_dmae_lock, flags);
if (dmaor & (DMAOR_AE | DMAOR_NMIF)) {
dev_warn(shdev->common.dev, "Can't initialize DMAOR.\n");
return -EIO;
}
return 0;
}
static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
{
u32 chcr = sh_dmae_readl(sh_chan, CHCR);
if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
return true; /* working */
return false; /* waiting */
}
static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
{
struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
struct sh_dmae_device, common);
struct sh_dmae_pdata *pdata = shdev->pdata;
int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
if (cnt >= pdata->ts_shift_num)
cnt = 0;
return pdata->ts_shift[cnt];
}
static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
{
struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
struct sh_dmae_device, common);
struct sh_dmae_pdata *pdata = shdev->pdata;
int i;
for (i = 0; i < pdata->ts_shift_num; i++)
if (pdata->ts_shift[i] == l2size)
break;
if (i == pdata->ts_shift_num)
i = 0;
return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
((i << pdata->ts_high_shift) & pdata->ts_high_mask);
}
static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
{
sh_dmae_writel(sh_chan, hw->sar, SAR);
sh_dmae_writel(sh_chan, hw->dar, DAR);
sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
}
static void dmae_start(struct sh_dmae_chan *sh_chan)
{
u32 chcr = sh_dmae_readl(sh_chan, CHCR);
chcr |= CHCR_DE | CHCR_IE;
sh_dmae_writel(sh_chan, chcr & ~CHCR_TE, CHCR);
}
static void dmae_halt(struct sh_dmae_chan *sh_chan)
{
u32 chcr = sh_dmae_readl(sh_chan, CHCR);
chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
sh_dmae_writel(sh_chan, chcr, CHCR);
}
static void dmae_init(struct sh_dmae_chan *sh_chan)
{
/*
* Default configuration for dual address memory-memory transfer.
* 0x400 represents auto-request.
*/
u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
LOG2_DEFAULT_XFER_SIZE);
sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
sh_dmae_writel(sh_chan, chcr, CHCR);
}
static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
{
/* If DMA is active, cannot set CHCR. TODO: remove this superfluous check */
if (dmae_is_busy(sh_chan))
return -EBUSY;
sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
sh_dmae_writel(sh_chan, val, CHCR);
return 0;
}
static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
{
struct sh_dmae_device *shdev = container_of(sh_chan->common.device,
struct sh_dmae_device, common);
struct sh_dmae_pdata *pdata = shdev->pdata;
const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->id];
u16 __iomem *addr = shdev->dmars;
int shift = chan_pdata->dmars_bit;
if (dmae_is_busy(sh_chan))
return -EBUSY;
/* in the case of a missing DMARS resource use first memory window */
if (!addr)
addr = (u16 __iomem *)shdev->chan_reg;
addr += chan_pdata->dmars / sizeof(u16);
__raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
addr);
return 0;
}
static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
dma_async_tx_callback callback = tx->callback;
dma_cookie_t cookie;
spin_lock_bh(&sh_chan->desc_lock);
cookie = sh_chan->common.cookie;
cookie++;
if (cookie < 0)
cookie = 1;
sh_chan->common.cookie = cookie;
tx->cookie = cookie;
/* Mark all chunks of this descriptor as submitted, move to the queue */
list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
/*
* All chunks are on the global ld_free, so, we have to find
* the end of the chain ourselves
*/
if (chunk != desc && (chunk->mark == DESC_IDLE ||
chunk->async_tx.cookie > 0 ||
chunk->async_tx.cookie == -EBUSY ||
&chunk->node == &sh_chan->ld_free))
break;
chunk->mark = DESC_SUBMITTED;
/* Callback goes to the last chunk */
chunk->async_tx.callback = NULL;
chunk->cookie = cookie;
list_move_tail(&chunk->node, &sh_chan->ld_queue);
last = chunk;
}
last->async_tx.callback = callback;
last->async_tx.callback_param = tx->callback_param;
dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
tx->cookie, &last->async_tx, sh_chan->id,
desc->hw.sar, desc->hw.tcr, desc->hw.dar);
spin_unlock_bh(&sh_chan->desc_lock);
return cookie;
}
/* Called with desc_lock held */
static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
{
struct sh_desc *desc;
list_for_each_entry(desc, &sh_chan->ld_free, node)
if (desc->mark != DESC_PREPARED) {
BUG_ON(desc->mark != DESC_IDLE);
list_del(&desc->node);
return desc;
}
return NULL;
}
static const struct sh_dmae_slave_config *sh_dmae_find_slave(
struct sh_dmae_chan *sh_chan, struct sh_dmae_slave *param)
{
struct dma_device *dma_dev = sh_chan->common.device;
struct sh_dmae_device *shdev = container_of(dma_dev,
struct sh_dmae_device, common);
struct sh_dmae_pdata *pdata = shdev->pdata;
int i;
if (param->slave_id >= SH_DMA_SLAVE_NUMBER)
return NULL;
for (i = 0; i < pdata->slave_num; i++)
if (pdata->slave[i].slave_id == param->slave_id)
return pdata->slave + i;
return NULL;
}
static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
struct sh_desc *desc;
struct sh_dmae_slave *param = chan->private;
int ret;
pm_runtime_get_sync(sh_chan->dev);
/*
* This relies on the guarantee from dmaengine that alloc_chan_resources
* never runs concurrently with itself or free_chan_resources.
*/
if (param) {
const struct sh_dmae_slave_config *cfg;
cfg = sh_dmae_find_slave(sh_chan, param);
if (!cfg) {
ret = -EINVAL;
goto efindslave;
}
if (test_and_set_bit(param->slave_id, sh_dmae_slave_used)) {
ret = -EBUSY;
goto etestused;
}
param->config = cfg;
dmae_set_dmars(sh_chan, cfg->mid_rid);
dmae_set_chcr(sh_chan, cfg->chcr);
} else {
dmae_init(sh_chan);
}
spin_lock_bh(&sh_chan->desc_lock);
while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
spin_unlock_bh(&sh_chan->desc_lock);
desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
if (!desc) {
spin_lock_bh(&sh_chan->desc_lock);
break;
}
dma_async_tx_descriptor_init(&desc->async_tx,
&sh_chan->common);
desc->async_tx.tx_submit = sh_dmae_tx_submit;
desc->mark = DESC_IDLE;
spin_lock_bh(&sh_chan->desc_lock);
list_add(&desc->node, &sh_chan->ld_free);
sh_chan->descs_allocated++;
}
spin_unlock_bh(&sh_chan->desc_lock);
if (!sh_chan->descs_allocated) {
ret = -ENOMEM;
goto edescalloc;
}
return sh_chan->descs_allocated;
edescalloc:
if (param)
clear_bit(param->slave_id, sh_dmae_slave_used);
etestused:
efindslave:
pm_runtime_put(sh_chan->dev);
return ret;
}
/*
* sh_dma_free_chan_resources - Free all resources of the channel.
*/
static void sh_dmae_free_chan_resources(struct dma_chan *chan)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
struct sh_desc *desc, *_desc;
LIST_HEAD(list);
int descs = sh_chan->descs_allocated;
/* Protect against ISR */
spin_lock_irq(&sh_chan->desc_lock);
dmae_halt(sh_chan);
spin_unlock_irq(&sh_chan->desc_lock);
/* Now no new interrupts will occur */
/* Prepared and not submitted descriptors can still be on the queue */
if (!list_empty(&sh_chan->ld_queue))
sh_dmae_chan_ld_cleanup(sh_chan, true);
if (chan->private) {
/* The caller is holding dma_list_mutex */
struct sh_dmae_slave *param = chan->private;
clear_bit(param->slave_id, sh_dmae_slave_used);
chan->private = NULL;
}
spin_lock_bh(&sh_chan->desc_lock);
list_splice_init(&sh_chan->ld_free, &list);
sh_chan->descs_allocated = 0;
spin_unlock_bh(&sh_chan->desc_lock);
if (descs > 0)
pm_runtime_put(sh_chan->dev);
list_for_each_entry_safe(desc, _desc, &list, node)
kfree(desc);
}
/**
* sh_dmae_add_desc - get, set up and return one transfer descriptor
* @sh_chan: DMA channel
* @flags: DMA transfer flags
* @dest: destination DMA address, incremented when direction equals
* DMA_FROM_DEVICE or DMA_BIDIRECTIONAL
* @src: source DMA address, incremented when direction equals
* DMA_TO_DEVICE or DMA_BIDIRECTIONAL
* @len: DMA transfer length
* @first: if NULL, set to the current descriptor and cookie set to -EBUSY
* @direction: needed for slave DMA to decide which address to keep constant,
* equals DMA_BIDIRECTIONAL for MEMCPY
* Returns 0 or an error
* Locks: called with desc_lock held
*/
static struct sh_desc *sh_dmae_add_desc(struct sh_dmae_chan *sh_chan,
unsigned long flags, dma_addr_t *dest, dma_addr_t *src, size_t *len,
struct sh_desc **first, enum dma_data_direction direction)
{
struct sh_desc *new;
size_t copy_size;
if (!*len)
return NULL;
/* Allocate the link descriptor from the free list */
new = sh_dmae_get_desc(sh_chan);
if (!new) {
dev_err(sh_chan->dev, "No free link descriptor available\n");
return NULL;
}
copy_size = min(*len, (size_t)SH_DMA_TCR_MAX + 1);
new->hw.sar = *src;
new->hw.dar = *dest;
new->hw.tcr = copy_size;
if (!*first) {
/* First desc */
new->async_tx.cookie = -EBUSY;
*first = new;
} else {
/* Other desc - invisible to the user */
new->async_tx.cookie = -EINVAL;
}
dev_dbg(sh_chan->dev,
"chaining (%u/%u)@%x -> %x with %p, cookie %d, shift %d\n",
copy_size, *len, *src, *dest, &new->async_tx,
new->async_tx.cookie, sh_chan->xmit_shift);
new->mark = DESC_PREPARED;
new->async_tx.flags = flags;
new->direction = direction;
*len -= copy_size;
if (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE)
*src += copy_size;
if (direction == DMA_BIDIRECTIONAL || direction == DMA_FROM_DEVICE)
*dest += copy_size;
return new;
}
/*
* sh_dmae_prep_sg - prepare transfer descriptors from an SG list
*
* Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
* converted to scatter-gather to guarantee consistent locking and a correct
* list manipulation. For slave DMA direction carries the usual meaning, and,
* logically, the SG list is RAM and the addr variable contains slave address,
* e.g., the FIFO I/O register. For MEMCPY direction equals DMA_BIDIRECTIONAL
* and the SG list contains only one element and points at the source buffer.
*/
static struct dma_async_tx_descriptor *sh_dmae_prep_sg(struct sh_dmae_chan *sh_chan,
struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
enum dma_data_direction direction, unsigned long flags)
{
struct scatterlist *sg;
struct sh_desc *first = NULL, *new = NULL /* compiler... */;
LIST_HEAD(tx_list);
int chunks = 0;
int i;
if (!sg_len)
return NULL;
for_each_sg(sgl, sg, sg_len, i)
chunks += (sg_dma_len(sg) + SH_DMA_TCR_MAX) /
(SH_DMA_TCR_MAX + 1);
/* Have to lock the whole loop to protect against concurrent release */
spin_lock_bh(&sh_chan->desc_lock);
/*
* Chaining:
* first descriptor is what user is dealing with in all API calls, its
* cookie is at first set to -EBUSY, at tx-submit to a positive
* number
* if more than one chunk is needed further chunks have cookie = -EINVAL
* the last chunk, if not equal to the first, has cookie = -ENOSPC
* all chunks are linked onto the tx_list head with their .node heads
* only during this function, then they are immediately spliced
* back onto the free list in form of a chain
*/
for_each_sg(sgl, sg, sg_len, i) {
dma_addr_t sg_addr = sg_dma_address(sg);
size_t len = sg_dma_len(sg);
if (!len)
goto err_get_desc;
do {
dev_dbg(sh_chan->dev, "Add SG #%d@%p[%d], dma %llx\n",
i, sg, len, (unsigned long long)sg_addr);
if (direction == DMA_FROM_DEVICE)
new = sh_dmae_add_desc(sh_chan, flags,
&sg_addr, addr, &len, &first,
direction);
else
new = sh_dmae_add_desc(sh_chan, flags,
addr, &sg_addr, &len, &first,
direction);
if (!new)
goto err_get_desc;
new->chunks = chunks--;
list_add_tail(&new->node, &tx_list);
} while (len);
}
if (new != first)
new->async_tx.cookie = -ENOSPC;
/* Put them back on the free list, so, they don't get lost */
list_splice_tail(&tx_list, &sh_chan->ld_free);
spin_unlock_bh(&sh_chan->desc_lock);
return &first->async_tx;
err_get_desc:
list_for_each_entry(new, &tx_list, node)
new->mark = DESC_IDLE;
list_splice(&tx_list, &sh_chan->ld_free);
spin_unlock_bh(&sh_chan->desc_lock);
return NULL;
}
static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
size_t len, unsigned long flags)
{
struct sh_dmae_chan *sh_chan;
struct scatterlist sg;
if (!chan || !len)
return NULL;
sh_chan = to_sh_chan(chan);
sg_init_table(&sg, 1);
sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len,
offset_in_page(dma_src));
sg_dma_address(&sg) = dma_src;
sg_dma_len(&sg) = len;
return sh_dmae_prep_sg(sh_chan, &sg, 1, &dma_dest, DMA_BIDIRECTIONAL,
flags);
}
static struct dma_async_tx_descriptor *sh_dmae_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
enum dma_data_direction direction, unsigned long flags)
{
struct sh_dmae_slave *param;
struct sh_dmae_chan *sh_chan;
dma_addr_t slave_addr;
if (!chan)
return NULL;
sh_chan = to_sh_chan(chan);
param = chan->private;
/* Someone calling slave DMA on a public channel? */
if (!param || !sg_len) {
dev_warn(sh_chan->dev, "%s: bad parameter: %p, %d, %d\n",
__func__, param, sg_len, param ? param->slave_id : -1);
return NULL;
}
slave_addr = param->config->addr;
/*
* if (param != NULL), this is a successfully requested slave channel,
* therefore param->config != NULL too.
*/
return sh_dmae_prep_sg(sh_chan, sgl, sg_len, &slave_addr,
direction, flags);
}
static int sh_dmae_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
/* Only supports DMA_TERMINATE_ALL */
if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
if (!chan)
return -EINVAL;
spin_lock_bh(&sh_chan->desc_lock);
dmae_halt(sh_chan);
if (!list_empty(&sh_chan->ld_queue)) {
/* Record partial transfer */
struct sh_desc *desc = list_entry(sh_chan->ld_queue.next,
struct sh_desc, node);
desc->partial = (desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
sh_chan->xmit_shift;
}
spin_unlock_bh(&sh_chan->desc_lock);
sh_dmae_chan_ld_cleanup(sh_chan, true);
return 0;
}
static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
{
struct sh_desc *desc, *_desc;
/* Is the "exposed" head of a chain acked? */
bool head_acked = false;
dma_cookie_t cookie = 0;
dma_async_tx_callback callback = NULL;
void *param = NULL;
spin_lock_bh(&sh_chan->desc_lock);
list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
struct dma_async_tx_descriptor *tx = &desc->async_tx;
BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
BUG_ON(desc->mark != DESC_SUBMITTED &&
desc->mark != DESC_COMPLETED &&
desc->mark != DESC_WAITING);
/*
* queue is ordered, and we use this loop to (1) clean up all
* completed descriptors, and to (2) update descriptor flags of
* any chunks in a (partially) completed chain
*/
if (!all && desc->mark == DESC_SUBMITTED &&
desc->cookie != cookie)
break;
if (tx->cookie > 0)
cookie = tx->cookie;
if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
if (sh_chan->completed_cookie != desc->cookie - 1)
dev_dbg(sh_chan->dev,
"Completing cookie %d, expected %d\n",
desc->cookie,
sh_chan->completed_cookie + 1);
sh_chan->completed_cookie = desc->cookie;
}
/* Call callback on the last chunk */
if (desc->mark == DESC_COMPLETED && tx->callback) {
desc->mark = DESC_WAITING;
callback = tx->callback;
param = tx->callback_param;
dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
tx->cookie, tx, sh_chan->id);
BUG_ON(desc->chunks != 1);
break;
}
if (tx->cookie > 0 || tx->cookie == -EBUSY) {
if (desc->mark == DESC_COMPLETED) {
BUG_ON(tx->cookie < 0);
desc->mark = DESC_WAITING;
}
head_acked = async_tx_test_ack(tx);
} else {
switch (desc->mark) {
case DESC_COMPLETED:
desc->mark = DESC_WAITING;
/* Fall through */
case DESC_WAITING:
if (head_acked)
async_tx_ack(&desc->async_tx);
}
}
dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
tx, tx->cookie);
if (((desc->mark == DESC_COMPLETED ||
desc->mark == DESC_WAITING) &&
async_tx_test_ack(&desc->async_tx)) || all) {
/* Remove from ld_queue list */
desc->mark = DESC_IDLE;
list_move(&desc->node, &sh_chan->ld_free);
}
}
if (all && !callback)
/*
* Terminating and the loop completed normally: forgive
* uncompleted cookies
*/
sh_chan->completed_cookie = sh_chan->common.cookie;
spin_unlock_bh(&sh_chan->desc_lock);
if (callback)
callback(param);
return callback;
}
/*
* sh_chan_ld_cleanup - Clean up link descriptors
*
* This function cleans up the ld_queue of DMA channel.
*/
static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
{
while (__ld_cleanup(sh_chan, all))
;
}
static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
{
struct sh_desc *desc;
spin_lock_bh(&sh_chan->desc_lock);
/* DMA work check */
if (dmae_is_busy(sh_chan)) {
spin_unlock_bh(&sh_chan->desc_lock);
return;
}
/* Find the first not transferred descriptor */
list_for_each_entry(desc, &sh_chan->ld_queue, node)
if (desc->mark == DESC_SUBMITTED) {
dev_dbg(sh_chan->dev, "Queue #%d to %d: %u@%x -> %x\n",
desc->async_tx.cookie, sh_chan->id,
desc->hw.tcr, desc->hw.sar, desc->hw.dar);
/* Get the ld start address from ld_queue */
dmae_set_reg(sh_chan, &desc->hw);
dmae_start(sh_chan);
break;
}
spin_unlock_bh(&sh_chan->desc_lock);
}
static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
sh_chan_xfer_ld_queue(sh_chan);
}
static enum dma_status sh_dmae_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
dma_cookie_t last_used;
dma_cookie_t last_complete;
enum dma_status status;
sh_dmae_chan_ld_cleanup(sh_chan, false);
/* First read completed cookie to avoid a skew */
last_complete = sh_chan->completed_cookie;
rmb();
last_used = chan->cookie;
BUG_ON(last_complete < 0);
dma_set_tx_state(txstate, last_complete, last_used, 0);
spin_lock_bh(&sh_chan->desc_lock);
status = dma_async_is_complete(cookie, last_complete, last_used);
/*
* If we don't find cookie on the queue, it has been aborted and we have
* to report error
*/
if (status != DMA_SUCCESS) {
struct sh_desc *desc;
status = DMA_ERROR;
list_for_each_entry(desc, &sh_chan->ld_queue, node)
if (desc->cookie == cookie) {
status = DMA_IN_PROGRESS;
break;
}
}
spin_unlock_bh(&sh_chan->desc_lock);
return status;
}
static irqreturn_t sh_dmae_interrupt(int irq, void *data)
{
irqreturn_t ret = IRQ_NONE;
struct sh_dmae_chan *sh_chan = data;
u32 chcr;
spin_lock(&sh_chan->desc_lock);
chcr = sh_dmae_readl(sh_chan, CHCR);
if (chcr & CHCR_TE) {
/* DMA stop */
dmae_halt(sh_chan);
ret = IRQ_HANDLED;
tasklet_schedule(&sh_chan->tasklet);
}
spin_unlock(&sh_chan->desc_lock);
return ret;
}
/* Called from error IRQ or NMI */
static bool sh_dmae_reset(struct sh_dmae_device *shdev)
{
unsigned int handled = 0;
int i;
/* halt the dma controller */
sh_dmae_ctl_stop(shdev);
/* We cannot detect, which channel caused the error, have to reset all */
for (i = 0; i < SH_DMAC_MAX_CHANNELS; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
struct sh_desc *desc;
LIST_HEAD(dl);
if (!sh_chan)
continue;
spin_lock(&sh_chan->desc_lock);
/* Stop the channel */
dmae_halt(sh_chan);
list_splice_init(&sh_chan->ld_queue, &dl);
spin_unlock(&sh_chan->desc_lock);
/* Complete all */
list_for_each_entry(desc, &dl, node) {
struct dma_async_tx_descriptor *tx = &desc->async_tx;
desc->mark = DESC_IDLE;
if (tx->callback)
tx->callback(tx->callback_param);
}
spin_lock(&sh_chan->desc_lock);
list_splice(&dl, &sh_chan->ld_free);
spin_unlock(&sh_chan->desc_lock);
handled++;
}
sh_dmae_rst(shdev);
return !!handled;
}
static irqreturn_t sh_dmae_err(int irq, void *data)
{
struct sh_dmae_device *shdev = data;
if (!(dmaor_read(shdev) & DMAOR_AE))
return IRQ_NONE;
sh_dmae_reset(data);
return IRQ_HANDLED;
}
static void dmae_do_tasklet(unsigned long data)
{
struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
struct sh_desc *desc;
u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
spin_lock(&sh_chan->desc_lock);
list_for_each_entry(desc, &sh_chan->ld_queue, node) {
if (desc->mark == DESC_SUBMITTED &&
((desc->direction == DMA_FROM_DEVICE &&
(desc->hw.dar + desc->hw.tcr) == dar_buf) ||
(desc->hw.sar + desc->hw.tcr) == sar_buf)) {
dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
desc->async_tx.cookie, &desc->async_tx,
desc->hw.dar);
desc->mark = DESC_COMPLETED;
break;
}
}
spin_unlock(&sh_chan->desc_lock);
/* Next desc */
sh_chan_xfer_ld_queue(sh_chan);
sh_dmae_chan_ld_cleanup(sh_chan, false);
}
static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
{
/* Fast path out if NMIF is not asserted for this controller */
if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
return false;
return sh_dmae_reset(shdev);
}
static int sh_dmae_nmi_handler(struct notifier_block *self,
unsigned long cmd, void *data)
{
struct sh_dmae_device *shdev;
int ret = NOTIFY_DONE;
bool triggered;
/*
* Only concern ourselves with NMI events.
*
* Normally we would check the die chain value, but as this needs
* to be architecture independent, check for NMI context instead.
*/
if (!in_nmi())
return NOTIFY_DONE;
rcu_read_lock();
list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
/*
* Only stop if one of the controllers has NMIF asserted,
* we do not want to interfere with regular address error
* handling or NMI events that don't concern the DMACs.
*/
triggered = sh_dmae_nmi_notify(shdev);
if (triggered == true)
ret = NOTIFY_OK;
}
rcu_read_unlock();
return ret;
}
static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
.notifier_call = sh_dmae_nmi_handler,
/* Run before NMI debug handler and KGDB */
.priority = 1,
};
static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
int irq, unsigned long flags)
{
int err;
const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
struct platform_device *pdev = to_platform_device(shdev->common.dev);
struct sh_dmae_chan *new_sh_chan;
/* alloc channel */
new_sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
if (!new_sh_chan) {
dev_err(shdev->common.dev,
"No free memory for allocating dma channels!\n");
return -ENOMEM;
}
/* copy struct dma_device */
new_sh_chan->common.device = &shdev->common;
new_sh_chan->dev = shdev->common.dev;
new_sh_chan->id = id;
new_sh_chan->irq = irq;
new_sh_chan->base = shdev->chan_reg + chan_pdata->offset / sizeof(u32);
/* Init DMA tasklet */
tasklet_init(&new_sh_chan->tasklet, dmae_do_tasklet,
(unsigned long)new_sh_chan);
spin_lock_init(&new_sh_chan->desc_lock);
/* Init descripter manage list */
INIT_LIST_HEAD(&new_sh_chan->ld_queue);
INIT_LIST_HEAD(&new_sh_chan->ld_free);
/* Add the channel to DMA device channel list */
list_add_tail(&new_sh_chan->common.device_node,
&shdev->common.channels);
shdev->common.chancnt++;
if (pdev->id >= 0)
snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
"sh-dmae%d.%d", pdev->id, new_sh_chan->id);
else
snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
"sh-dma%d", new_sh_chan->id);
/* set up channel irq */
err = request_irq(irq, &sh_dmae_interrupt, flags,
new_sh_chan->dev_id, new_sh_chan);
if (err) {
dev_err(shdev->common.dev, "DMA channel %d request_irq error "
"with return %d\n", id, err);
goto err_no_irq;
}
shdev->chan[id] = new_sh_chan;
return 0;
err_no_irq:
/* remove from dmaengine device node */
list_del(&new_sh_chan->common.device_node);
kfree(new_sh_chan);
return err;
}
static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
{
int i;
for (i = shdev->common.chancnt - 1 ; i >= 0 ; i--) {
if (shdev->chan[i]) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
free_irq(sh_chan->irq, sh_chan);
list_del(&sh_chan->common.device_node);
kfree(sh_chan);
shdev->chan[i] = NULL;
}
}
shdev->common.chancnt = 0;
}
static int __init sh_dmae_probe(struct platform_device *pdev)
{
struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
unsigned long irqflags = IRQF_DISABLED,
chan_flag[SH_DMAC_MAX_CHANNELS] = {};
int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
int err, i, irq_cnt = 0, irqres = 0, irq_cap = 0;
struct sh_dmae_device *shdev;
struct resource *chan, *dmars, *errirq_res, *chanirq_res;
/* get platform data */
if (!pdata || !pdata->channel_num)
return -ENODEV;
chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
/* DMARS area is optional */
dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
/*
* IRQ resources:
* 1. there always must be at least one IRQ IO-resource. On SH4 it is
* the error IRQ, in which case it is the only IRQ in this resource:
* start == end. If it is the only IRQ resource, all channels also
* use the same IRQ.
* 2. DMA channel IRQ resources can be specified one per resource or in
* ranges (start != end)
* 3. iff all events (channels and, optionally, error) on this
* controller use the same IRQ, only one IRQ resource can be
* specified, otherwise there must be one IRQ per channel, even if
* some of them are equal
* 4. if all IRQs on this controller are equal or if some specific IRQs
* specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
* requested with the IRQF_SHARED flag
*/
errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!chan || !errirq_res)
return -ENODEV;
if (!request_mem_region(chan->start, resource_size(chan), pdev->name)) {
dev_err(&pdev->dev, "DMAC register region already claimed\n");
return -EBUSY;
}
if (dmars && !request_mem_region(dmars->start, resource_size(dmars), pdev->name)) {
dev_err(&pdev->dev, "DMAC DMARS region already claimed\n");
err = -EBUSY;
goto ermrdmars;
}
err = -ENOMEM;
shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
if (!shdev) {
dev_err(&pdev->dev, "Not enough memory\n");
goto ealloc;
}
shdev->chan_reg = ioremap(chan->start, resource_size(chan));
if (!shdev->chan_reg)
goto emapchan;
if (dmars) {
shdev->dmars = ioremap(dmars->start, resource_size(dmars));
if (!shdev->dmars)
goto emapdmars;
}
/* platform data */
shdev->pdata = pdata;
platform_set_drvdata(pdev, shdev);
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
spin_lock_irq(&sh_dmae_lock);
list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
spin_unlock_irq(&sh_dmae_lock);
/* reset dma controller - only needed as a test */
err = sh_dmae_rst(shdev);
if (err)
goto rst_err;
INIT_LIST_HEAD(&shdev->common.channels);
dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
if (pdata->slave && pdata->slave_num)
dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
shdev->common.device_alloc_chan_resources
= sh_dmae_alloc_chan_resources;
shdev->common.device_free_chan_resources = sh_dmae_free_chan_resources;
shdev->common.device_prep_dma_memcpy = sh_dmae_prep_memcpy;
shdev->common.device_tx_status = sh_dmae_tx_status;
shdev->common.device_issue_pending = sh_dmae_memcpy_issue_pending;
/* Compulsory for DMA_SLAVE fields */
shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
shdev->common.device_control = sh_dmae_control;
shdev->common.dev = &pdev->dev;
/* Default transfer size of 32 bytes requires 32-byte alignment */
shdev->common.copy_align = LOG2_DEFAULT_XFER_SIZE;
#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
if (!chanirq_res)
chanirq_res = errirq_res;
else
irqres++;
if (chanirq_res == errirq_res ||
(errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
irqflags = IRQF_SHARED;
errirq = errirq_res->start;
err = request_irq(errirq, sh_dmae_err, irqflags,
"DMAC Address Error", shdev);
if (err) {
dev_err(&pdev->dev,
"DMA failed requesting irq #%d, error %d\n",
errirq, err);
goto eirq_err;
}
#else
chanirq_res = errirq_res;
#endif /* CONFIG_CPU_SH4 || CONFIG_ARCH_SHMOBILE */
if (chanirq_res->start == chanirq_res->end &&
!platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
/* Special case - all multiplexed */
for (; irq_cnt < pdata->channel_num; irq_cnt++) {
if (irq_cnt < SH_DMAC_MAX_CHANNELS) {
chan_irq[irq_cnt] = chanirq_res->start;
chan_flag[irq_cnt] = IRQF_SHARED;
} else {
irq_cap = 1;
break;
}
}
} else {
do {
for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
if (irq_cnt >= SH_DMAC_MAX_CHANNELS) {
irq_cap = 1;
break;
}
if ((errirq_res->flags & IORESOURCE_BITS) ==
IORESOURCE_IRQ_SHAREABLE)
chan_flag[irq_cnt] = IRQF_SHARED;
else
chan_flag[irq_cnt] = IRQF_DISABLED;
dev_dbg(&pdev->dev,
"Found IRQ %d for channel %d\n",
i, irq_cnt);
chan_irq[irq_cnt++] = i;
}
if (irq_cnt >= SH_DMAC_MAX_CHANNELS)
break;
chanirq_res = platform_get_resource(pdev,
IORESOURCE_IRQ, ++irqres);
} while (irq_cnt < pdata->channel_num && chanirq_res);
}
/* Create DMA Channel */
for (i = 0; i < irq_cnt; i++) {
err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
if (err)
goto chan_probe_err;
}
if (irq_cap)
dev_notice(&pdev->dev, "Attempting to register %d DMA "
"channels when a maximum of %d are supported.\n",
pdata->channel_num, SH_DMAC_MAX_CHANNELS);
pm_runtime_put(&pdev->dev);
dma_async_device_register(&shdev->common);
return err;
chan_probe_err:
sh_dmae_chan_remove(shdev);
#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
free_irq(errirq, shdev);
eirq_err:
#endif
rst_err:
spin_lock_irq(&sh_dmae_lock);
list_del_rcu(&shdev->node);
spin_unlock_irq(&sh_dmae_lock);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
if (dmars)
iounmap(shdev->dmars);
platform_set_drvdata(pdev, NULL);
emapdmars:
iounmap(shdev->chan_reg);
synchronize_rcu();
emapchan:
kfree(shdev);
ealloc:
if (dmars)
release_mem_region(dmars->start, resource_size(dmars));
ermrdmars:
release_mem_region(chan->start, resource_size(chan));
return err;
}
static int __exit sh_dmae_remove(struct platform_device *pdev)
{
struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
struct resource *res;
int errirq = platform_get_irq(pdev, 0);
dma_async_device_unregister(&shdev->common);
if (errirq > 0)
free_irq(errirq, shdev);
spin_lock_irq(&sh_dmae_lock);
list_del_rcu(&shdev->node);
spin_unlock_irq(&sh_dmae_lock);
/* channel data remove */
sh_dmae_chan_remove(shdev);
pm_runtime_disable(&pdev->dev);
if (shdev->dmars)
iounmap(shdev->dmars);
iounmap(shdev->chan_reg);
platform_set_drvdata(pdev, NULL);
synchronize_rcu();
kfree(shdev);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res)
release_mem_region(res->start, resource_size(res));
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res)
release_mem_region(res->start, resource_size(res));
return 0;
}
static void sh_dmae_shutdown(struct platform_device *pdev)
{
struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
sh_dmae_ctl_stop(shdev);
}
static int sh_dmae_runtime_suspend(struct device *dev)
{
return 0;
}
static int sh_dmae_runtime_resume(struct device *dev)
{
struct sh_dmae_device *shdev = dev_get_drvdata(dev);
return sh_dmae_rst(shdev);
}
#ifdef CONFIG_PM
static int sh_dmae_suspend(struct device *dev)
{
struct sh_dmae_device *shdev = dev_get_drvdata(dev);
int i;
for (i = 0; i < shdev->pdata->channel_num; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
if (sh_chan->descs_allocated)
sh_chan->pm_error = pm_runtime_put_sync(dev);
}
return 0;
}
static int sh_dmae_resume(struct device *dev)
{
struct sh_dmae_device *shdev = dev_get_drvdata(dev);
int i;
for (i = 0; i < shdev->pdata->channel_num; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
struct sh_dmae_slave *param = sh_chan->common.private;
if (!sh_chan->descs_allocated)
continue;
if (!sh_chan->pm_error)
pm_runtime_get_sync(dev);
if (param) {
const struct sh_dmae_slave_config *cfg = param->config;
dmae_set_dmars(sh_chan, cfg->mid_rid);
dmae_set_chcr(sh_chan, cfg->chcr);
} else {
dmae_init(sh_chan);
}
}
return 0;
}
#else
#define sh_dmae_suspend NULL
#define sh_dmae_resume NULL
#endif
const struct dev_pm_ops sh_dmae_pm = {
.suspend = sh_dmae_suspend,
.resume = sh_dmae_resume,
.runtime_suspend = sh_dmae_runtime_suspend,
.runtime_resume = sh_dmae_runtime_resume,
};
static struct platform_driver sh_dmae_driver = {
.remove = __exit_p(sh_dmae_remove),
.shutdown = sh_dmae_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "sh-dma-engine",
.pm = &sh_dmae_pm,
},
};
static int __init sh_dmae_init(void)
{
/* Wire up NMI handling */
int err = register_die_notifier(&sh_dmae_nmi_notifier);
if (err)
return err;
return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
}
module_init(sh_dmae_init);
static void __exit sh_dmae_exit(void)
{
platform_driver_unregister(&sh_dmae_driver);
unregister_die_notifier(&sh_dmae_nmi_notifier);
}
module_exit(sh_dmae_exit);
MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sh-dma-engine");