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linux-sg2042/drivers/dma/fsldma.c

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/*
* Freescale MPC85xx, MPC83xx DMA Engine support
*
* Copyright (C) 2007-2010 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 "dmaengine.h"
#include "fsldma.h"
#define chan_dbg(chan, fmt, arg...) \
dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
#define chan_err(chan, fmt, arg...) \
dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
static const char msg_ld_oom[] = "No free memory for link descriptor";
/*
* Register Helpers
*/
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_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 u32 get_bcr(struct fsldma_chan *chan)
{
return DMA_IN(chan, &chan->regs->bcr, 32);
}
/*
* Descriptor Helpers
*/
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 u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
{
return DMA_TO_CPU(chan, desc->hw.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 dma_addr_t get_desc_src(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits;
}
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 dma_addr_t get_desc_dst(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
u64 snoop_bits;
snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits;
}
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_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);
}
/*
* DMA Engine Hardware Control Helpers
*/
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
* EOLNIE - End of links interrupt enable
* BWC - Bandwidth sharing among channels
*/
DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
| FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE, 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 int dma_is_idle(struct fsldma_chan *chan)
{
u32 sr = get_sr(chan);
return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
}
/*
* Start the DMA controller
*
* Preconditions:
* - the CDAR register must point to the start descriptor
* - the MRn[CS] bit must be cleared
*/
static void dma_start(struct fsldma_chan *chan)
{
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
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_EMS_EN;
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;
/* read the mode register */
mode = DMA_IN(chan, &chan->regs->mr, 32);
/*
* The 85xx controller supports channel abort, which will stop
* the current transfer. On 83xx, this bit is the transfer error
* mask bit, which should not be changed.
*/
if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
mode |= FSL_DMA_MR_CA;
DMA_OUT(chan, &chan->regs->mr, mode, 32);
mode &= ~FSL_DMA_MR_CA;
}
/* stop the DMA controller */
mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
DMA_OUT(chan, &chan->regs->mr, mode, 32);
/* wait for the DMA controller to become idle */
for (i = 0; i < 100; i++) {
if (dma_is_idle(chan))
return;
udelay(10);
}
if (!dma_is_idle(chan))
chan_err(chan, "DMA halt timeout!\n");
}
/**
* 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
*/
list_for_each_entry(child, &desc->tx_list, node) {
cookie = dma_cookie_assign(&child->async_tx);
}
/* 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) {
chan_dbg(chan, "out of memory for link descriptor\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;
#ifdef FSL_DMA_LD_DEBUG
chan_dbg(chan, "LD %p allocated\n", desc);
#endif
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(chan->name, chan->dev,
sizeof(struct fsl_desc_sw),
__alignof__(struct fsl_desc_sw), 0);
if (!chan->desc_pool) {
chan_err(chan, "unable to allocate descriptor pool\n");
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);
#ifdef FSL_DMA_LD_DEBUG
chan_dbg(chan, "LD %p free\n", desc);
#endif
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);
#ifdef FSL_DMA_LD_DEBUG
chan_dbg(chan, "LD %p free\n", desc);
#endif
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;
chan_dbg(chan, "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) {
chan_err(chan, "%s\n", 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) {
chan_err(chan, "%s\n", msg_ld_oom);
goto fail;
}
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) {
chan_err(chan, "%s\n", msg_ld_oom);
goto fail;
}
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
* @context: transaction context (ignored)
*
* 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_transfer_direction direction, unsigned long flags,
void *context)
{
/*
* 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:
spin_lock_irqsave(&chan->desc_lock, flags);
/* Halt the DMA engine */
dma_halt(chan);
/* 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);
chan->idle = true;
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_MEM_TO_DEV)
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;
}
/**
* fsldma_cleanup_descriptor - cleanup and free a single link descriptor
* @chan: Freescale DMA channel
* @desc: descriptor to cleanup and free
*
* This function is used on a descriptor which has been executed by the DMA
* controller. It will run any callbacks, submit any dependencies, and then
* free the descriptor.
*/
static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
struct fsl_desc_sw *desc)
{
struct dma_async_tx_descriptor *txd = &desc->async_tx;
struct device *dev = chan->common.device->dev;
dma_addr_t src = get_desc_src(chan, desc);
dma_addr_t dst = get_desc_dst(chan, desc);
u32 len = get_desc_cnt(chan, desc);
/* Run the link descriptor callback function */
if (txd->callback) {
#ifdef FSL_DMA_LD_DEBUG
chan_dbg(chan, "LD %p callback\n", desc);
#endif
txd->callback(txd->callback_param);
}
/* Run any dependencies */
dma_run_dependencies(txd);
/* Unmap the dst buffer, if requested */
if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE);
else
dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE);
}
/* Unmap the src buffer, if requested */
if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
dma_unmap_single(dev, src, len, DMA_TO_DEVICE);
else
dma_unmap_page(dev, src, len, DMA_TO_DEVICE);
}
#ifdef FSL_DMA_LD_DEBUG
chan_dbg(chan, "LD %p free\n", desc);
#endif
dma_pool_free(chan->desc_pool, desc, txd->phys);
}
/**
* fsl_chan_xfer_ld_queue - transfer any pending transactions
* @chan : Freescale DMA channel
*
* HARDWARE STATE: idle
* LOCKING: must hold chan->desc_lock
*/
static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
{
struct fsl_desc_sw *desc;
/*
* 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)) {
chan_dbg(chan, "no pending LDs\n");
return;
}
/*
* The DMA controller is not idle, which means that the interrupt
* handler will start any queued transactions when it runs after
* this transaction finishes
*/
if (!chan->idle) {
chan_dbg(chan, "DMA controller still busy\n");
return;
}
/*
* 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
*/
chan_dbg(chan, "idle, starting controller\n");
desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
/*
* The 85xx DMA controller doesn't clear the channel start bit
* automatically at the end of a transfer. Therefore we must clear
* it in software before starting the transfer.
*/
if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
u32 mode;
mode = DMA_IN(chan, &chan->regs->mr, 32);
mode &= ~FSL_DMA_MR_CS;
DMA_OUT(chan, &chan->regs->mr, mode, 32);
}
/*
* Program the descriptor's address into the DMA controller,
* then start the DMA transaction
*/
set_cdar(chan, desc->async_tx.phys);
get_cdar(chan);
dma_start(chan);
chan->idle = false;
}
/**
* 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);
unsigned long flags;
spin_lock_irqsave(&chan->desc_lock, flags);
fsl_chan_xfer_ld_queue(chan);
spin_unlock_irqrestore(&chan->desc_lock, flags);
}
/**
* 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)
{
return dma_cookie_status(dchan, cookie, txstate);
}
/*----------------------------------------------------------------------------*/
/* Interrupt Handling */
/*----------------------------------------------------------------------------*/
static irqreturn_t fsldma_chan_irq(int irq, void *data)
{
struct fsldma_chan *chan = data;
u32 stat;
/* save and clear the status register */
stat = get_sr(chan);
set_sr(chan, stat);
chan_dbg(chan, "irq: stat = 0x%x\n", stat);
/* check that this was really our device */
stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
if (!stat)
return IRQ_NONE;
if (stat & FSL_DMA_SR_TE)
chan_err(chan, "Transfer Error!\n");
/*
* Programming Error
* The DMA_INTERRUPT async_tx is a NULL transfer, which will
* trigger a PE interrupt.
*/
if (stat & FSL_DMA_SR_PE) {
chan_dbg(chan, "irq: Programming Error INT\n");
stat &= ~FSL_DMA_SR_PE;
if (get_bcr(chan) != 0)
chan_err(chan, "Programming Error!\n");
}
/*
* For MPC8349, EOCDI event need to update cookie
* and start the next transfer if it exist.
*/
if (stat & FSL_DMA_SR_EOCDI) {
chan_dbg(chan, "irq: End-of-Chain link INT\n");
stat &= ~FSL_DMA_SR_EOCDI;
}
/*
* 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) {
chan_dbg(chan, "irq: End-of-link INT\n");
stat &= ~FSL_DMA_SR_EOLNI;
}
/* check that the DMA controller is really idle */
if (!dma_is_idle(chan))
chan_err(chan, "irq: controller not idle!\n");
/* check that we handled all of the bits */
if (stat)
chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
/*
* Schedule the tasklet to handle all cleanup of the current
* transaction. It will start a new transaction if there is
* one pending.
*/
tasklet_schedule(&chan->tasklet);
chan_dbg(chan, "irq: Exit\n");
return IRQ_HANDLED;
}
static void dma_do_tasklet(unsigned long data)
{
struct fsldma_chan *chan = (struct fsldma_chan *)data;
struct fsl_desc_sw *desc, *_desc;
LIST_HEAD(ld_cleanup);
unsigned long flags;
chan_dbg(chan, "tasklet entry\n");
spin_lock_irqsave(&chan->desc_lock, flags);
/* update the cookie if we have some descriptors to cleanup */
if (!list_empty(&chan->ld_running)) {
dma_cookie_t cookie;
desc = to_fsl_desc(chan->ld_running.prev);
cookie = desc->async_tx.cookie;
dma_cookie_complete(&desc->async_tx);
chan_dbg(chan, "completed_cookie=%d\n", cookie);
}
/*
* move the descriptors to a temporary list so we can drop the lock
* during the entire cleanup operation
*/
list_splice_tail_init(&chan->ld_running, &ld_cleanup);
/* the hardware is now idle and ready for more */
chan->idle = true;
/*
* Start any pending transactions automatically
*
* In the ideal case, we keep the DMA controller busy while we go
* ahead and free the descriptors below.
*/
fsl_chan_xfer_ld_queue(chan);
spin_unlock_irqrestore(&chan->desc_lock, flags);
/* Run the callback for each descriptor, in order */
list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
/* Remove from the list of transactions */
list_del(&desc->node);
/* Run all cleanup for this descriptor */
fsldma_cleanup_descriptor(chan, desc);
}
chan_dbg(chan, "tasklet exit\n");
}
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) {
chan_dbg(chan, "free per-channel IRQ\n");
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) {
chan_err(chan, "interrupts property missing in device tree\n");
ret = -ENODEV;
goto out_unwind;
}
chan_dbg(chan, "request per-channel IRQ\n");
ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
"fsldma-chan", chan);
if (ret) {
chan_err(chan, "unable to request per-channel IRQ\n");
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 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);
snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
/* 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->idle = true;
chan->common.device = &fdev->common;
dma_cookie_init(&chan->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 fsldma_of_probe(struct platform_device *op)
{
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;
dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
platform_set_drvdata(op, 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 = platform_get_drvdata(op);
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);
kfree(fdev);
return 0;
}
static const struct of_device_id fsldma_of_ids[] = {
{ .compatible = "fsl,eloplus-dma", },
{ .compatible = "fsl,elo-dma", },
{}
};
static struct 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)
{
pr_info("Freescale Elo / Elo Plus DMA driver\n");
return platform_driver_register(&fsldma_of_driver);
}
static void __exit fsldma_exit(void)
{
platform_driver_unregister(&fsldma_of_driver);
}
subsys_initcall(fsldma_init);
module_exit(fsldma_exit);
MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
MODULE_LICENSE("GPL");
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