linux/drivers/dma/fsldma.c

1445 lines
36 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 contorller 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 <asm/fsldma.h>
#include "fsldma.h"
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, "No free memory for link descriptor\n");
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,
"No free memory for link descriptor\n");
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;
}
/**
* 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)
{
struct fsldma_chan *chan;
struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
struct fsl_dma_slave *slave;
size_t copy;
int i;
struct scatterlist *sg;
size_t sg_used;
size_t hw_used;
struct fsl_dma_hw_addr *hw;
dma_addr_t dma_dst, dma_src;
if (!dchan)
return NULL;
if (!dchan->private)
return NULL;
chan = to_fsl_chan(dchan);
slave = dchan->private;
if (list_empty(&slave->addresses))
return NULL;
hw = list_first_entry(&slave->addresses, struct fsl_dma_hw_addr, entry);
hw_used = 0;
/*
* Build the hardware transaction to copy from the scatterlist to
* the hardware, or from the hardware to the scatterlist
*
* If you are copying from the hardware to the scatterlist and it
* takes two hardware entries to fill an entire page, then both
* hardware entries will be coalesced into the same page
*
* If you are copying from the scatterlist to the hardware and a
* single page can fill two hardware entries, then the data will
* be read out of the page into the first hardware entry, and so on
*/
for_each_sg(sgl, sg, sg_len, i) {
sg_used = 0;
/* Loop until the entire scatterlist entry is used */
while (sg_used < sg_dma_len(sg)) {
/*
* If we've used up the current hardware address/length
* pair, we need to load a new one
*
* This is done in a while loop so that descriptors with
* length == 0 will be skipped
*/
while (hw_used >= hw->length) {
/*
* If the current hardware entry is the last
* entry in the list, we're finished
*/
if (list_is_last(&hw->entry, &slave->addresses))
goto finished;
/* Get the next hardware address/length pair */
hw = list_entry(hw->entry.next,
struct fsl_dma_hw_addr, entry);
hw_used = 0;
}
/* Allocate the link descriptor from DMA pool */
new = fsl_dma_alloc_descriptor(chan);
if (!new) {
dev_err(chan->dev, "No free memory for "
"link descriptor\n");
goto fail;
}
#ifdef FSL_DMA_LD_DEBUG
dev_dbg(chan->dev, "new link desc alloc %p\n", new);
#endif
/*
* Calculate the maximum number of bytes to transfer,
* making sure it is less than the DMA controller limit
*/
copy = min_t(size_t, sg_dma_len(sg) - sg_used,
hw->length - hw_used);
copy = min_t(size_t, copy, FSL_DMA_BCR_MAX_CNT);
/*
* DMA_FROM_DEVICE
* from the hardware to the scatterlist
*
* DMA_TO_DEVICE
* from the scatterlist to the hardware
*/
if (direction == DMA_FROM_DEVICE) {
dma_src = hw->address + hw_used;
dma_dst = sg_dma_address(sg) + sg_used;
} else {
dma_src = sg_dma_address(sg) + sg_used;
dma_dst = hw->address + hw_used;
}
/* Fill in the descriptor */
set_desc_cnt(chan, &new->hw, copy);
set_desc_src(chan, &new->hw, dma_src);
set_desc_dst(chan, &new->hw, dma_dst);
/*
* If this is not the first descriptor, chain the
* current descriptor after the previous descriptor
*/
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;
sg_used += copy;
hw_used += copy;
/* Insert the link descriptor into the LD ring */
list_add_tail(&new->node, &first->tx_list);
}
}
finished:
/* All of the hardware address/length pairs had length == 0 */
if (!first || !new)
return NULL;
new->async_tx.flags = flags;
new->async_tx.cookie = -EBUSY;
/* Set End-of-link to the last link descriptor of new list */
set_ld_eol(chan, new);
/* Enable extra controller features */
if (chan->set_src_loop_size)
chan->set_src_loop_size(chan, slave->src_loop_size);
if (chan->set_dst_loop_size)
chan->set_dst_loop_size(chan, slave->dst_loop_size);
if (chan->toggle_ext_start)
chan->toggle_ext_start(chan, slave->external_start);
if (chan->toggle_ext_pause)
chan->toggle_ext_pause(chan, slave->external_pause);
if (chan->set_request_count)
chan->set_request_count(chan, slave->request_count);
return &first->async_tx;
fail:
/* If first was not set, then we failed to allocate the very first
* descriptor, and we're done */
if (!first)
return NULL;
/*
* First is set, so all of the descriptors we allocated have been added
* to first->tx_list, INCLUDING "first" itself. Therefore we
* must traverse the list backwards freeing each descriptor in turn
*
* We're re-using variables for the loop, oh well
*/
fsldma_free_desc_list_reverse(chan, &first->tx_list);
return NULL;
}
static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
{
struct fsldma_chan *chan;
unsigned long flags;
if (!dchan)
return;
chan = to_fsl_chan(dchan);
/* 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);
}
/**
* 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_dma_is_complete - Determine the DMA status
* @chan : Freescale DMA channel
*/
static enum dma_status fsl_dma_is_complete(struct dma_chan *dchan,
dma_cookie_t cookie,
dma_cookie_t *done,
dma_cookie_t *used)
{
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;
if (done)
*done = last_complete;
if (used)
*used = last_used;
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 of_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->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->node, 0);
dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
dma_cap_set(DMA_INTERRUPT, 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_is_tx_complete = fsl_dma_is_complete;
fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
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->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 of_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 = {
.name = "fsl-elo-dma",
.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");