linux-stable/drivers/dma/fsldma.c
Ira Snyder 968f19ae80 fsldma: improved DMA_SLAVE support
Now that the generic DMAEngine API has support for scatterlist to
scatterlist copying, the device_prep_slave_sg() portion of the
DMA_SLAVE API is no longer necessary and has been removed.

However, the device_control() portion of the DMA_SLAVE API is still
useful to control device specific parameters, such as externally
controlled DMA transfers and maximum burst length.

A special dma_ctrl_cmd has been added to enable externally controlled
DMA transfers. This is currently specific to the Freescale DMA
controller, but can easily be made generic when another user is found.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-10-07 14:41:41 -07:00

1433 lines
35 KiB
C

/*
* Freescale MPC85xx, MPC83xx DMA Engine support
*
* Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
*
* Author:
* Zhang Wei <wei.zhang@freescale.com>, Jul 2007
* Ebony Zhu <ebony.zhu@freescale.com>, May 2007
*
* Description:
* DMA engine driver for Freescale MPC8540 DMA controller, which is
* also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
* The support for MPC8349 DMA controller is also added.
*
* This driver instructs the DMA controller to issue the PCI Read Multiple
* command for PCI read operations, instead of using the default PCI Read Line
* command. Please be aware that this setting may result in read pre-fetching
* on some platforms.
*
* 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.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/of_platform.h>
#include "fsldma.h"
static const char msg_ld_oom[] = "No free memory for link descriptor\n";
static void dma_init(struct fsldma_chan *chan)
{
/* Reset the channel */
DMA_OUT(chan, &chan->regs->mr, 0, 32);
switch (chan->feature & FSL_DMA_IP_MASK) {
case FSL_DMA_IP_85XX:
/* Set the channel to below modes:
* EIE - Error interrupt enable
* EOSIE - End of segments interrupt enable (basic mode)
* EOLNIE - End of links interrupt enable
*/
DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EIE
| FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
break;
case FSL_DMA_IP_83XX:
/* Set the channel to below modes:
* EOTIE - End-of-transfer interrupt enable
* PRC_RM - PCI read multiple
*/
DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
| FSL_DMA_MR_PRC_RM, 32);
break;
}
}
static void set_sr(struct fsldma_chan *chan, u32 val)
{
DMA_OUT(chan, &chan->regs->sr, val, 32);
}
static u32 get_sr(struct fsldma_chan *chan)
{
return DMA_IN(chan, &chan->regs->sr, 32);
}
static void set_desc_cnt(struct fsldma_chan *chan,
struct fsl_dma_ld_hw *hw, u32 count)
{
hw->count = CPU_TO_DMA(chan, count, 32);
}
static void set_desc_src(struct fsldma_chan *chan,
struct fsl_dma_ld_hw *hw, dma_addr_t src)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
}
static void set_desc_dst(struct fsldma_chan *chan,
struct fsl_dma_ld_hw *hw, dma_addr_t dst)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
}
static void set_desc_next(struct fsldma_chan *chan,
struct fsl_dma_ld_hw *hw, dma_addr_t next)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
? FSL_DMA_SNEN : 0;
hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
}
static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
{
DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
}
static dma_addr_t get_cdar(struct fsldma_chan *chan)
{
return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
}
static dma_addr_t get_ndar(struct fsldma_chan *chan)
{
return DMA_IN(chan, &chan->regs->ndar, 64);
}
static u32 get_bcr(struct fsldma_chan *chan)
{
return DMA_IN(chan, &chan->regs->bcr, 32);
}
static int dma_is_idle(struct fsldma_chan *chan)
{
u32 sr = get_sr(chan);
return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
}
static void dma_start(struct fsldma_chan *chan)
{
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
DMA_OUT(chan, &chan->regs->bcr, 0, 32);
mode |= FSL_DMA_MR_EMP_EN;
} else {
mode &= ~FSL_DMA_MR_EMP_EN;
}
}
if (chan->feature & FSL_DMA_CHAN_START_EXT)
mode |= FSL_DMA_MR_EMS_EN;
else
mode |= FSL_DMA_MR_CS;
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
static void dma_halt(struct fsldma_chan *chan)
{
u32 mode;
int i;
mode = DMA_IN(chan, &chan->regs->mr, 32);
mode |= FSL_DMA_MR_CA;
DMA_OUT(chan, &chan->regs->mr, mode, 32);
mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
DMA_OUT(chan, &chan->regs->mr, mode, 32);
for (i = 0; i < 100; i++) {
if (dma_is_idle(chan))
return;
udelay(10);
}
if (!dma_is_idle(chan))
dev_err(chan->dev, "DMA halt timeout!\n");
}
static void set_ld_eol(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
? FSL_DMA_SNEN : 0;
desc->hw.next_ln_addr = CPU_TO_DMA(chan,
DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
| snoop_bits, 64);
}
/**
* fsl_chan_set_src_loop_size - Set source address hold transfer size
* @chan : Freescale DMA channel
* @size : Address loop size, 0 for disable loop
*
* The set source address hold transfer size. The source
* address hold or loop transfer size is when the DMA transfer
* data from source address (SA), if the loop size is 4, the DMA will
* read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
* SA + 1 ... and so on.
*/
static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
{
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
switch (size) {
case 0:
mode &= ~FSL_DMA_MR_SAHE;
break;
case 1:
case 2:
case 4:
case 8:
mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14);
break;
}
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
/**
* fsl_chan_set_dst_loop_size - Set destination address hold transfer size
* @chan : Freescale DMA channel
* @size : Address loop size, 0 for disable loop
*
* The set destination address hold transfer size. The destination
* address hold or loop transfer size is when the DMA transfer
* data to destination address (TA), if the loop size is 4, the DMA will
* write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
* TA + 1 ... and so on.
*/
static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
{
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
switch (size) {
case 0:
mode &= ~FSL_DMA_MR_DAHE;
break;
case 1:
case 2:
case 4:
case 8:
mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16);
break;
}
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
/**
* fsl_chan_set_request_count - Set DMA Request Count for external control
* @chan : Freescale DMA channel
* @size : Number of bytes to transfer in a single request
*
* The Freescale DMA channel can be controlled by the external signal DREQ#.
* The DMA request count is how many bytes are allowed to transfer before
* pausing the channel, after which a new assertion of DREQ# resumes channel
* operation.
*
* A size of 0 disables external pause control. The maximum size is 1024.
*/
static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
{
u32 mode;
BUG_ON(size > 1024);
mode = DMA_IN(chan, &chan->regs->mr, 32);
mode |= (__ilog2(size) << 24) & 0x0f000000;
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
/**
* fsl_chan_toggle_ext_pause - Toggle channel external pause status
* @chan : Freescale DMA channel
* @enable : 0 is disabled, 1 is enabled.
*
* The Freescale DMA channel can be controlled by the external signal DREQ#.
* The DMA Request Count feature should be used in addition to this feature
* to set the number of bytes to transfer before pausing the channel.
*/
static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
{
if (enable)
chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
else
chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
}
/**
* fsl_chan_toggle_ext_start - Toggle channel external start status
* @chan : Freescale DMA channel
* @enable : 0 is disabled, 1 is enabled.
*
* If enable the external start, the channel can be started by an
* external DMA start pin. So the dma_start() does not start the
* transfer immediately. The DMA channel will wait for the
* control pin asserted.
*/
static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
{
if (enable)
chan->feature |= FSL_DMA_CHAN_START_EXT;
else
chan->feature &= ~FSL_DMA_CHAN_START_EXT;
}
static void append_ld_queue(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
if (list_empty(&chan->ld_pending))
goto out_splice;
/*
* Add the hardware descriptor to the chain of hardware descriptors
* that already exists in memory.
*
* This will un-set the EOL bit of the existing transaction, and the
* last link in this transaction will become the EOL descriptor.
*/
set_desc_next(chan, &tail->hw, desc->async_tx.phys);
/*
* Add the software descriptor and all children to the list
* of pending transactions
*/
out_splice:
list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
}
static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct fsldma_chan *chan = to_fsl_chan(tx->chan);
struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
struct fsl_desc_sw *child;
unsigned long flags;
dma_cookie_t cookie;
spin_lock_irqsave(&chan->desc_lock, flags);
/*
* assign cookies to all of the software descriptors
* that make up this transaction
*/
cookie = chan->common.cookie;
list_for_each_entry(child, &desc->tx_list, node) {
cookie++;
if (cookie < 0)
cookie = 1;
child->async_tx.cookie = cookie;
}
chan->common.cookie = cookie;
/* put this transaction onto the tail of the pending queue */
append_ld_queue(chan, desc);
spin_unlock_irqrestore(&chan->desc_lock, flags);
return cookie;
}
/**
* fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
* @chan : Freescale DMA channel
*
* Return - The descriptor allocated. NULL for failed.
*/
static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
dma_addr_t pdesc;
desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
if (!desc) {
dev_dbg(chan->dev, "out of memory for link desc\n");
return NULL;
}
memset(desc, 0, sizeof(*desc));
INIT_LIST_HEAD(&desc->tx_list);
dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
desc->async_tx.tx_submit = fsl_dma_tx_submit;
desc->async_tx.phys = pdesc;
return desc;
}
/**
* fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
* @chan : Freescale DMA channel
*
* This function will create a dma pool for descriptor allocation.
*
* Return - The number of descriptors allocated.
*/
static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
/* Has this channel already been allocated? */
if (chan->desc_pool)
return 1;
/*
* We need the descriptor to be aligned to 32bytes
* for meeting FSL DMA specification requirement.
*/
chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
chan->dev,
sizeof(struct fsl_desc_sw),
__alignof__(struct fsl_desc_sw), 0);
if (!chan->desc_pool) {
dev_err(chan->dev, "unable to allocate channel %d "
"descriptor pool\n", chan->id);
return -ENOMEM;
}
/* there is at least one descriptor free to be allocated */
return 1;
}
/**
* fsldma_free_desc_list - Free all descriptors in a queue
* @chan: Freescae DMA channel
* @list: the list to free
*
* LOCKING: must hold chan->desc_lock
*/
static void fsldma_free_desc_list(struct fsldma_chan *chan,
struct list_head *list)
{
struct fsl_desc_sw *desc, *_desc;
list_for_each_entry_safe(desc, _desc, list, node) {
list_del(&desc->node);
dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
}
}
static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
struct list_head *list)
{
struct fsl_desc_sw *desc, *_desc;
list_for_each_entry_safe_reverse(desc, _desc, list, node) {
list_del(&desc->node);
dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
}
}
/**
* fsl_dma_free_chan_resources - Free all resources of the channel.
* @chan : Freescale DMA channel
*/
static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
unsigned long flags;
dev_dbg(chan->dev, "Free all channel resources.\n");
spin_lock_irqsave(&chan->desc_lock, flags);
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
spin_unlock_irqrestore(&chan->desc_lock, flags);
dma_pool_destroy(chan->desc_pool);
chan->desc_pool = NULL;
}
static struct dma_async_tx_descriptor *
fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
{
struct fsldma_chan *chan;
struct fsl_desc_sw *new;
if (!dchan)
return NULL;
chan = to_fsl_chan(dchan);
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
dev_err(chan->dev, msg_ld_oom);
return NULL;
}
new->async_tx.cookie = -EBUSY;
new->async_tx.flags = flags;
/* Insert the link descriptor to the LD ring */
list_add_tail(&new->node, &new->tx_list);
/* Set End-of-link to the last link descriptor of new list*/
set_ld_eol(chan, new);
return &new->async_tx;
}
static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src,
size_t len, unsigned long flags)
{
struct fsldma_chan *chan;
struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
size_t copy;
if (!dchan)
return NULL;
if (!len)
return NULL;
chan = to_fsl_chan(dchan);
do {
/* Allocate the link descriptor from DMA pool */
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
dev_err(chan->dev, msg_ld_oom);
goto fail;
}
#ifdef FSL_DMA_LD_DEBUG
dev_dbg(chan->dev, "new link desc alloc %p\n", new);
#endif
copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
set_desc_cnt(chan, &new->hw, copy);
set_desc_src(chan, &new->hw, dma_src);
set_desc_dst(chan, &new->hw, dma_dst);
if (!first)
first = new;
else
set_desc_next(chan, &prev->hw, new->async_tx.phys);
new->async_tx.cookie = 0;
async_tx_ack(&new->async_tx);
prev = new;
len -= copy;
dma_src += copy;
dma_dst += copy;
/* Insert the link descriptor to the LD ring */
list_add_tail(&new->node, &first->tx_list);
} while (len);
new->async_tx.flags = flags; /* client is in control of this ack */
new->async_tx.cookie = -EBUSY;
/* Set End-of-link to the last link descriptor of new list*/
set_ld_eol(chan, new);
return &first->async_tx;
fail:
if (!first)
return NULL;
fsldma_free_desc_list_reverse(chan, &first->tx_list);
return NULL;
}
static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
struct scatterlist *dst_sg, unsigned int dst_nents,
struct scatterlist *src_sg, unsigned int src_nents,
unsigned long flags)
{
struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
struct fsldma_chan *chan = to_fsl_chan(dchan);
size_t dst_avail, src_avail;
dma_addr_t dst, src;
size_t len;
/* basic sanity checks */
if (dst_nents == 0 || src_nents == 0)
return NULL;
if (dst_sg == NULL || src_sg == NULL)
return NULL;
/*
* TODO: should we check that both scatterlists have the same
* TODO: number of bytes in total? Is that really an error?
*/
/* get prepared for the loop */
dst_avail = sg_dma_len(dst_sg);
src_avail = sg_dma_len(src_sg);
/* run until we are out of scatterlist entries */
while (true) {
/* create the largest transaction possible */
len = min_t(size_t, src_avail, dst_avail);
len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
if (len == 0)
goto fetch;
dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
/* allocate and populate the descriptor */
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
dev_err(chan->dev, msg_ld_oom);
goto fail;
}
#ifdef FSL_DMA_LD_DEBUG
dev_dbg(chan->dev, "new link desc alloc %p\n", new);
#endif
set_desc_cnt(chan, &new->hw, len);
set_desc_src(chan, &new->hw, src);
set_desc_dst(chan, &new->hw, dst);
if (!first)
first = new;
else
set_desc_next(chan, &prev->hw, new->async_tx.phys);
new->async_tx.cookie = 0;
async_tx_ack(&new->async_tx);
prev = new;
/* Insert the link descriptor to the LD ring */
list_add_tail(&new->node, &first->tx_list);
/* update metadata */
dst_avail -= len;
src_avail -= len;
fetch:
/* fetch the next dst scatterlist entry */
if (dst_avail == 0) {
/* no more entries: we're done */
if (dst_nents == 0)
break;
/* fetch the next entry: if there are no more: done */
dst_sg = sg_next(dst_sg);
if (dst_sg == NULL)
break;
dst_nents--;
dst_avail = sg_dma_len(dst_sg);
}
/* fetch the next src scatterlist entry */
if (src_avail == 0) {
/* no more entries: we're done */
if (src_nents == 0)
break;
/* fetch the next entry: if there are no more: done */
src_sg = sg_next(src_sg);
if (src_sg == NULL)
break;
src_nents--;
src_avail = sg_dma_len(src_sg);
}
}
new->async_tx.flags = flags; /* client is in control of this ack */
new->async_tx.cookie = -EBUSY;
/* Set End-of-link to the last link descriptor of new list */
set_ld_eol(chan, new);
return &first->async_tx;
fail:
if (!first)
return NULL;
fsldma_free_desc_list_reverse(chan, &first->tx_list);
return NULL;
}
/**
* fsl_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
* @chan: DMA channel
* @sgl: scatterlist to transfer to/from
* @sg_len: number of entries in @scatterlist
* @direction: DMA direction
* @flags: DMAEngine flags
*
* Prepare a set of descriptors for a DMA_SLAVE transaction. Following the
* DMA_SLAVE API, this gets the device-specific information from the
* chan->private variable.
*/
static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
enum dma_data_direction direction, unsigned long flags)
{
/*
* This operation is not supported on the Freescale DMA controller
*
* However, we need to provide the function pointer to allow the
* device_control() method to work.
*/
return NULL;
}
static int fsl_dma_device_control(struct dma_chan *dchan,
enum dma_ctrl_cmd cmd, unsigned long arg)
{
struct dma_slave_config *config;
struct fsldma_chan *chan;
unsigned long flags;
int size;
if (!dchan)
return -EINVAL;
chan = to_fsl_chan(dchan);
switch (cmd) {
case DMA_TERMINATE_ALL:
/* Halt the DMA engine */
dma_halt(chan);
spin_lock_irqsave(&chan->desc_lock, flags);
/* Remove and free all of the descriptors in the LD queue */
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
spin_unlock_irqrestore(&chan->desc_lock, flags);
return 0;
case DMA_SLAVE_CONFIG:
config = (struct dma_slave_config *)arg;
/* make sure the channel supports setting burst size */
if (!chan->set_request_count)
return -ENXIO;
/* we set the controller burst size depending on direction */
if (config->direction == DMA_TO_DEVICE)
size = config->dst_addr_width * config->dst_maxburst;
else
size = config->src_addr_width * config->src_maxburst;
chan->set_request_count(chan, size);
return 0;
case FSLDMA_EXTERNAL_START:
/* make sure the channel supports external start */
if (!chan->toggle_ext_start)
return -ENXIO;
chan->toggle_ext_start(chan, arg);
return 0;
default:
return -ENXIO;
}
return 0;
}
/**
* fsl_dma_update_completed_cookie - Update the completed cookie.
* @chan : Freescale DMA channel
*
* CONTEXT: hardirq
*/
static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
unsigned long flags;
dma_cookie_t cookie;
spin_lock_irqsave(&chan->desc_lock, flags);
if (list_empty(&chan->ld_running)) {
dev_dbg(chan->dev, "no running descriptors\n");
goto out_unlock;
}
/* Get the last descriptor, update the cookie to that */
desc = to_fsl_desc(chan->ld_running.prev);
if (dma_is_idle(chan))
cookie = desc->async_tx.cookie;
else {
cookie = desc->async_tx.cookie - 1;
if (unlikely(cookie < DMA_MIN_COOKIE))
cookie = DMA_MAX_COOKIE;
}
chan->completed_cookie = cookie;
out_unlock:
spin_unlock_irqrestore(&chan->desc_lock, flags);
}
/**
* fsldma_desc_status - Check the status of a descriptor
* @chan: Freescale DMA channel
* @desc: DMA SW descriptor
*
* This function will return the status of the given descriptor
*/
static enum dma_status fsldma_desc_status(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
return dma_async_is_complete(desc->async_tx.cookie,
chan->completed_cookie,
chan->common.cookie);
}
/**
* fsl_chan_ld_cleanup - Clean up link descriptors
* @chan : Freescale DMA channel
*
* This function clean up the ld_queue of DMA channel.
*/
static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc, *_desc;
unsigned long flags;
spin_lock_irqsave(&chan->desc_lock, flags);
dev_dbg(chan->dev, "chan completed_cookie = %d\n", chan->completed_cookie);
list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
dma_async_tx_callback callback;
void *callback_param;
if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
break;
/* Remove from the list of running transactions */
list_del(&desc->node);
/* Run the link descriptor callback function */
callback = desc->async_tx.callback;
callback_param = desc->async_tx.callback_param;
if (callback) {
spin_unlock_irqrestore(&chan->desc_lock, flags);
dev_dbg(chan->dev, "LD %p callback\n", desc);
callback(callback_param);
spin_lock_irqsave(&chan->desc_lock, flags);
}
/* Run any dependencies, then free the descriptor */
dma_run_dependencies(&desc->async_tx);
dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
}
spin_unlock_irqrestore(&chan->desc_lock, flags);
}
/**
* fsl_chan_xfer_ld_queue - transfer any pending transactions
* @chan : Freescale DMA channel
*
* This will make sure that any pending transactions will be run.
* If the DMA controller is idle, it will be started. Otherwise,
* the DMA controller's interrupt handler will start any pending
* transactions when it becomes idle.
*/
static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
unsigned long flags;
spin_lock_irqsave(&chan->desc_lock, flags);
/*
* If the list of pending descriptors is empty, then we
* don't need to do any work at all
*/
if (list_empty(&chan->ld_pending)) {
dev_dbg(chan->dev, "no pending LDs\n");
goto out_unlock;
}
/*
* The DMA controller is not idle, which means the interrupt
* handler will start any queued transactions when it runs
* at the end of the current transaction
*/
if (!dma_is_idle(chan)) {
dev_dbg(chan->dev, "DMA controller still busy\n");
goto out_unlock;
}
/*
* TODO:
* make sure the dma_halt() function really un-wedges the
* controller as much as possible
*/
dma_halt(chan);
/*
* If there are some link descriptors which have not been
* transferred, we need to start the controller
*/
/*
* Move all elements from the queue of pending transactions
* onto the list of running transactions
*/
desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
/*
* Program the descriptor's address into the DMA controller,
* then start the DMA transaction
*/
set_cdar(chan, desc->async_tx.phys);
dma_start(chan);
out_unlock:
spin_unlock_irqrestore(&chan->desc_lock, flags);
}
/**
* fsl_dma_memcpy_issue_pending - Issue the DMA start command
* @chan : Freescale DMA channel
*/
static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
fsl_chan_xfer_ld_queue(chan);
}
/**
* fsl_tx_status - Determine the DMA status
* @chan : Freescale DMA channel
*/
static enum dma_status fsl_tx_status(struct dma_chan *dchan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
dma_cookie_t last_used;
dma_cookie_t last_complete;
fsl_chan_ld_cleanup(chan);
last_used = dchan->cookie;
last_complete = chan->completed_cookie;
dma_set_tx_state(txstate, last_complete, last_used, 0);
return dma_async_is_complete(cookie, last_complete, last_used);
}
/*----------------------------------------------------------------------------*/
/* Interrupt Handling */
/*----------------------------------------------------------------------------*/
static irqreturn_t fsldma_chan_irq(int irq, void *data)
{
struct fsldma_chan *chan = data;
int update_cookie = 0;
int xfer_ld_q = 0;
u32 stat;
/* save and clear the status register */
stat = get_sr(chan);
set_sr(chan, stat);
dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat);
stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
if (!stat)
return IRQ_NONE;
if (stat & FSL_DMA_SR_TE)
dev_err(chan->dev, "Transfer Error!\n");
/*
* Programming Error
* The DMA_INTERRUPT async_tx is a NULL transfer, which will
* triger a PE interrupt.
*/
if (stat & FSL_DMA_SR_PE) {
dev_dbg(chan->dev, "irq: Programming Error INT\n");
if (get_bcr(chan) == 0) {
/* BCR register is 0, this is a DMA_INTERRUPT async_tx.
* Now, update the completed cookie, and continue the
* next uncompleted transfer.
*/
update_cookie = 1;
xfer_ld_q = 1;
}
stat &= ~FSL_DMA_SR_PE;
}
/*
* If the link descriptor segment transfer finishes,
* we will recycle the used descriptor.
*/
if (stat & FSL_DMA_SR_EOSI) {
dev_dbg(chan->dev, "irq: End-of-segments INT\n");
dev_dbg(chan->dev, "irq: clndar 0x%llx, nlndar 0x%llx\n",
(unsigned long long)get_cdar(chan),
(unsigned long long)get_ndar(chan));
stat &= ~FSL_DMA_SR_EOSI;
update_cookie = 1;
}
/*
* For MPC8349, EOCDI event need to update cookie
* and start the next transfer if it exist.
*/
if (stat & FSL_DMA_SR_EOCDI) {
dev_dbg(chan->dev, "irq: End-of-Chain link INT\n");
stat &= ~FSL_DMA_SR_EOCDI;
update_cookie = 1;
xfer_ld_q = 1;
}
/*
* If it current transfer is the end-of-transfer,
* we should clear the Channel Start bit for
* prepare next transfer.
*/
if (stat & FSL_DMA_SR_EOLNI) {
dev_dbg(chan->dev, "irq: End-of-link INT\n");
stat &= ~FSL_DMA_SR_EOLNI;
xfer_ld_q = 1;
}
if (update_cookie)
fsl_dma_update_completed_cookie(chan);
if (xfer_ld_q)
fsl_chan_xfer_ld_queue(chan);
if (stat)
dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat);
dev_dbg(chan->dev, "irq: Exit\n");
tasklet_schedule(&chan->tasklet);
return IRQ_HANDLED;
}
static void dma_do_tasklet(unsigned long data)
{
struct fsldma_chan *chan = (struct fsldma_chan *)data;
fsl_chan_ld_cleanup(chan);
}
static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
{
struct fsldma_device *fdev = data;
struct fsldma_chan *chan;
unsigned int handled = 0;
u32 gsr, mask;
int i;
gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
: in_le32(fdev->regs);
mask = 0xff000000;
dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
chan = fdev->chan[i];
if (!chan)
continue;
if (gsr & mask) {
dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
fsldma_chan_irq(irq, chan);
handled++;
}
gsr &= ~mask;
mask >>= 8;
}
return IRQ_RETVAL(handled);
}
static void fsldma_free_irqs(struct fsldma_device *fdev)
{
struct fsldma_chan *chan;
int i;
if (fdev->irq != NO_IRQ) {
dev_dbg(fdev->dev, "free per-controller IRQ\n");
free_irq(fdev->irq, fdev);
return;
}
for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
chan = fdev->chan[i];
if (chan && chan->irq != NO_IRQ) {
dev_dbg(fdev->dev, "free channel %d IRQ\n", chan->id);
free_irq(chan->irq, chan);
}
}
}
static int fsldma_request_irqs(struct fsldma_device *fdev)
{
struct fsldma_chan *chan;
int ret;
int i;
/* if we have a per-controller IRQ, use that */
if (fdev->irq != NO_IRQ) {
dev_dbg(fdev->dev, "request per-controller IRQ\n");
ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
"fsldma-controller", fdev);
return ret;
}
/* no per-controller IRQ, use the per-channel IRQs */
for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
chan = fdev->chan[i];
if (!chan)
continue;
if (chan->irq == NO_IRQ) {
dev_err(fdev->dev, "no interrupts property defined for "
"DMA channel %d. Please fix your "
"device tree\n", chan->id);
ret = -ENODEV;
goto out_unwind;
}
dev_dbg(fdev->dev, "request channel %d IRQ\n", chan->id);
ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
"fsldma-chan", chan);
if (ret) {
dev_err(fdev->dev, "unable to request IRQ for DMA "
"channel %d\n", chan->id);
goto out_unwind;
}
}
return 0;
out_unwind:
for (/* none */; i >= 0; i--) {
chan = fdev->chan[i];
if (!chan)
continue;
if (chan->irq == NO_IRQ)
continue;
free_irq(chan->irq, chan);
}
return ret;
}
/*----------------------------------------------------------------------------*/
/* OpenFirmware Subsystem */
/*----------------------------------------------------------------------------*/
static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
struct device_node *node, u32 feature, const char *compatible)
{
struct fsldma_chan *chan;
struct resource res;
int err;
/* alloc channel */
chan = kzalloc(sizeof(*chan), GFP_KERNEL);
if (!chan) {
dev_err(fdev->dev, "no free memory for DMA channels!\n");
err = -ENOMEM;
goto out_return;
}
/* ioremap registers for use */
chan->regs = of_iomap(node, 0);
if (!chan->regs) {
dev_err(fdev->dev, "unable to ioremap registers\n");
err = -ENOMEM;
goto out_free_chan;
}
err = of_address_to_resource(node, 0, &res);
if (err) {
dev_err(fdev->dev, "unable to find 'reg' property\n");
goto out_iounmap_regs;
}
chan->feature = feature;
if (!fdev->feature)
fdev->feature = chan->feature;
/*
* If the DMA device's feature is different than the feature
* of its channels, report the bug
*/
WARN_ON(fdev->feature != chan->feature);
chan->dev = fdev->dev;
chan->id = ((res.start - 0x100) & 0xfff) >> 7;
if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
dev_err(fdev->dev, "too many channels for device\n");
err = -EINVAL;
goto out_iounmap_regs;
}
fdev->chan[chan->id] = chan;
tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
/* Initialize the channel */
dma_init(chan);
/* Clear cdar registers */
set_cdar(chan, 0);
switch (chan->feature & FSL_DMA_IP_MASK) {
case FSL_DMA_IP_85XX:
chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
case FSL_DMA_IP_83XX:
chan->toggle_ext_start = fsl_chan_toggle_ext_start;
chan->set_src_loop_size = fsl_chan_set_src_loop_size;
chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
chan->set_request_count = fsl_chan_set_request_count;
}
spin_lock_init(&chan->desc_lock);
INIT_LIST_HEAD(&chan->ld_pending);
INIT_LIST_HEAD(&chan->ld_running);
chan->common.device = &fdev->common;
/* find the IRQ line, if it exists in the device tree */
chan->irq = irq_of_parse_and_map(node, 0);
/* Add the channel to DMA device channel list */
list_add_tail(&chan->common.device_node, &fdev->common.channels);
fdev->common.chancnt++;
dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
chan->irq != NO_IRQ ? chan->irq : fdev->irq);
return 0;
out_iounmap_regs:
iounmap(chan->regs);
out_free_chan:
kfree(chan);
out_return:
return err;
}
static void fsl_dma_chan_remove(struct fsldma_chan *chan)
{
irq_dispose_mapping(chan->irq);
list_del(&chan->common.device_node);
iounmap(chan->regs);
kfree(chan);
}
static int __devinit fsldma_of_probe(struct platform_device *op,
const struct of_device_id *match)
{
struct fsldma_device *fdev;
struct device_node *child;
int err;
fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
if (!fdev) {
dev_err(&op->dev, "No enough memory for 'priv'\n");
err = -ENOMEM;
goto out_return;
}
fdev->dev = &op->dev;
INIT_LIST_HEAD(&fdev->common.channels);
/* ioremap the registers for use */
fdev->regs = of_iomap(op->dev.of_node, 0);
if (!fdev->regs) {
dev_err(&op->dev, "unable to ioremap registers\n");
err = -ENOMEM;
goto out_free_fdev;
}
/* map the channel IRQ if it exists, but don't hookup the handler yet */
fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
dma_cap_set(DMA_SG, fdev->common.cap_mask);
dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
fdev->common.device_tx_status = fsl_tx_status;
fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
fdev->common.device_control = fsl_dma_device_control;
fdev->common.dev = &op->dev;
dev_set_drvdata(&op->dev, fdev);
/*
* We cannot use of_platform_bus_probe() because there is no
* of_platform_bus_remove(). Instead, we manually instantiate every DMA
* channel object.
*/
for_each_child_of_node(op->dev.of_node, child) {
if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
fsl_dma_chan_probe(fdev, child,
FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
"fsl,eloplus-dma-channel");
}
if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
fsl_dma_chan_probe(fdev, child,
FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
"fsl,elo-dma-channel");
}
}
/*
* Hookup the IRQ handler(s)
*
* If we have a per-controller interrupt, we prefer that to the
* per-channel interrupts to reduce the number of shared interrupt
* handlers on the same IRQ line
*/
err = fsldma_request_irqs(fdev);
if (err) {
dev_err(fdev->dev, "unable to request IRQs\n");
goto out_free_fdev;
}
dma_async_device_register(&fdev->common);
return 0;
out_free_fdev:
irq_dispose_mapping(fdev->irq);
kfree(fdev);
out_return:
return err;
}
static int fsldma_of_remove(struct platform_device *op)
{
struct fsldma_device *fdev;
unsigned int i;
fdev = dev_get_drvdata(&op->dev);
dma_async_device_unregister(&fdev->common);
fsldma_free_irqs(fdev);
for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
if (fdev->chan[i])
fsl_dma_chan_remove(fdev->chan[i]);
}
iounmap(fdev->regs);
dev_set_drvdata(&op->dev, NULL);
kfree(fdev);
return 0;
}
static const struct of_device_id fsldma_of_ids[] = {
{ .compatible = "fsl,eloplus-dma", },
{ .compatible = "fsl,elo-dma", },
{}
};
static struct of_platform_driver fsldma_of_driver = {
.driver = {
.name = "fsl-elo-dma",
.owner = THIS_MODULE,
.of_match_table = fsldma_of_ids,
},
.probe = fsldma_of_probe,
.remove = fsldma_of_remove,
};
/*----------------------------------------------------------------------------*/
/* Module Init / Exit */
/*----------------------------------------------------------------------------*/
static __init int fsldma_init(void)
{
int ret;
pr_info("Freescale Elo / Elo Plus DMA driver\n");
ret = of_register_platform_driver(&fsldma_of_driver);
if (ret)
pr_err("fsldma: failed to register platform driver\n");
return ret;
}
static void __exit fsldma_exit(void)
{
of_unregister_platform_driver(&fsldma_of_driver);
}
subsys_initcall(fsldma_init);
module_exit(fsldma_exit);
MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
MODULE_LICENSE("GPL");