linux/drivers/dma/imx-dma.c
Javier Martin 9e15db7ce9 dmaengine: Add support for multiple descriptors for imx-dma.
dmaengine specifies the possibility that several descriptors
can be queued for transfer. It also indicates that tasklets
must be used for DMA callbacks.

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-03-06 17:19:21 +05:30

662 lines
17 KiB
C

/*
* drivers/dma/imx-dma.c
*
* This file contains a driver for the Freescale i.MX DMA engine
* found on i.MX1/21/27
*
* Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
* Copyright 2012 Javier Martin, Vista Silicon <javier.martin@vista-silicon.com>
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
#include <asm/irq.h>
#include <mach/dma-v1.h>
#include <mach/hardware.h>
#define IMXDMA_MAX_CHAN_DESCRIPTORS 16
enum imxdma_prep_type {
IMXDMA_DESC_MEMCPY,
IMXDMA_DESC_INTERLEAVED,
IMXDMA_DESC_SLAVE_SG,
IMXDMA_DESC_CYCLIC,
};
struct imxdma_desc {
struct list_head node;
struct dma_async_tx_descriptor desc;
enum dma_status status;
dma_addr_t src;
dma_addr_t dest;
size_t len;
unsigned int dmamode;
enum imxdma_prep_type type;
/* For memcpy and interleaved */
unsigned int config_port;
unsigned int config_mem;
/* For interleaved transfers */
unsigned int x;
unsigned int y;
unsigned int w;
/* For slave sg and cyclic */
struct scatterlist *sg;
unsigned int sgcount;
};
struct imxdma_channel {
struct imxdma_engine *imxdma;
unsigned int channel;
unsigned int imxdma_channel;
struct tasklet_struct dma_tasklet;
struct list_head ld_free;
struct list_head ld_queue;
struct list_head ld_active;
int descs_allocated;
enum dma_slave_buswidth word_size;
dma_addr_t per_address;
u32 watermark_level;
struct dma_chan chan;
spinlock_t lock;
dma_cookie_t last_completed;
int dma_request;
struct scatterlist *sg_list;
};
#define MAX_DMA_CHANNELS 8
struct imxdma_engine {
struct device *dev;
struct device_dma_parameters dma_parms;
struct dma_device dma_device;
struct imxdma_channel channel[MAX_DMA_CHANNELS];
};
static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
{
return container_of(chan, struct imxdma_channel, chan);
}
static inline bool imxdma_chan_is_doing_cyclic(struct imxdma_channel *imxdmac)
{
struct imxdma_desc *desc;
if (!list_empty(&imxdmac->ld_active)) {
desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc,
node);
if (desc->type == IMXDMA_DESC_CYCLIC)
return true;
}
return false;
}
static void imxdma_irq_handler(int channel, void *data)
{
struct imxdma_channel *imxdmac = data;
tasklet_schedule(&imxdmac->dma_tasklet);
}
static void imxdma_err_handler(int channel, void *data, int error)
{
struct imxdma_channel *imxdmac = data;
tasklet_schedule(&imxdmac->dma_tasklet);
}
static void imxdma_progression(int channel, void *data,
struct scatterlist *sg)
{
struct imxdma_channel *imxdmac = data;
tasklet_schedule(&imxdmac->dma_tasklet);
}
static int imxdma_xfer_desc(struct imxdma_desc *d)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
int ret;
/* Configure and enable */
switch (d->type) {
case IMXDMA_DESC_MEMCPY:
ret = imx_dma_config_channel(imxdmac->imxdma_channel,
d->config_port, d->config_mem, 0, 0);
if (ret < 0)
return ret;
ret = imx_dma_setup_single(imxdmac->imxdma_channel, d->src,
d->len, d->dest, d->dmamode);
if (ret < 0)
return ret;
break;
case IMXDMA_DESC_CYCLIC:
ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
imxdma_progression);
if (ret < 0)
return ret;
/*
* We fall through here since cyclic transfer is the same as
* slave_sg adding a progression handler and a specific sg
* configuration which is done in 'imxdma_prep_dma_cyclic'.
*/
case IMXDMA_DESC_SLAVE_SG:
if (d->dmamode == DMA_MODE_READ)
ret = imx_dma_setup_sg(imxdmac->imxdma_channel, d->sg,
d->sgcount, d->len, d->src, d->dmamode);
else
ret = imx_dma_setup_sg(imxdmac->imxdma_channel, d->sg,
d->sgcount, d->len, d->dest, d->dmamode);
if (ret < 0)
return ret;
break;
default:
return -EINVAL;
}
imx_dma_enable(imxdmac->imxdma_channel);
return 0;
}
static void imxdma_tasklet(unsigned long data)
{
struct imxdma_channel *imxdmac = (void *)data;
struct imxdma_engine *imxdma = imxdmac->imxdma;
struct imxdma_desc *desc;
spin_lock(&imxdmac->lock);
if (list_empty(&imxdmac->ld_active)) {
/* Someone might have called terminate all */
goto out;
}
desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node);
if (desc->desc.callback)
desc->desc.callback(desc->desc.callback_param);
imxdmac->last_completed = desc->desc.cookie;
/* If we are dealing with a cyclic descriptor keep it on ld_active */
if (imxdma_chan_is_doing_cyclic(imxdmac))
goto out;
list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free);
if (!list_empty(&imxdmac->ld_queue)) {
desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc,
node);
list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active);
if (imxdma_xfer_desc(desc) < 0)
dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n",
__func__, imxdmac->channel);
}
out:
spin_unlock(&imxdmac->lock);
}
static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct dma_slave_config *dmaengine_cfg = (void *)arg;
int ret;
unsigned long flags;
unsigned int mode = 0;
switch (cmd) {
case DMA_TERMINATE_ALL:
imx_dma_disable(imxdmac->imxdma_channel);
spin_lock_irqsave(&imxdmac->lock, flags);
list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
spin_unlock_irqrestore(&imxdmac->lock, flags);
return 0;
case DMA_SLAVE_CONFIG:
if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
imxdmac->per_address = dmaengine_cfg->src_addr;
imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
imxdmac->word_size = dmaengine_cfg->src_addr_width;
} else {
imxdmac->per_address = dmaengine_cfg->dst_addr;
imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
imxdmac->word_size = dmaengine_cfg->dst_addr_width;
}
switch (imxdmac->word_size) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
mode = IMX_DMA_MEMSIZE_8;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
mode = IMX_DMA_MEMSIZE_16;
break;
default:
case DMA_SLAVE_BUSWIDTH_4_BYTES:
mode = IMX_DMA_MEMSIZE_32;
break;
}
ret = imx_dma_config_channel(imxdmac->imxdma_channel,
mode | IMX_DMA_TYPE_FIFO,
IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
imxdmac->dma_request, 1);
if (ret)
return ret;
imx_dma_config_burstlen(imxdmac->imxdma_channel,
imxdmac->watermark_level * imxdmac->word_size);
return 0;
default:
return -ENOSYS;
}
return -EINVAL;
}
static enum dma_status imxdma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
dma_cookie_t last_used;
enum dma_status ret;
unsigned long flags;
spin_lock_irqsave(&imxdmac->lock, flags);
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, imxdmac->last_completed, last_used);
dma_set_tx_state(txstate, imxdmac->last_completed, last_used, 0);
spin_unlock_irqrestore(&imxdmac->lock, flags);
return ret;
}
static dma_cookie_t imxdma_assign_cookie(struct imxdma_channel *imxdma)
{
dma_cookie_t cookie = imxdma->chan.cookie;
if (++cookie < 0)
cookie = 1;
imxdma->chan.cookie = cookie;
return cookie;
}
static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
dma_cookie_t cookie;
unsigned long flags;
spin_lock_irqsave(&imxdmac->lock, flags);
list_move_tail(imxdmac->ld_free.next, &imxdmac->ld_queue);
cookie = imxdma_assign_cookie(imxdmac);
tx->cookie = cookie;
spin_unlock_irqrestore(&imxdmac->lock, flags);
return cookie;
}
static int imxdma_alloc_chan_resources(struct dma_chan *chan)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imx_dma_data *data = chan->private;
if (data != NULL)
imxdmac->dma_request = data->dma_request;
while (imxdmac->descs_allocated < IMXDMA_MAX_CHAN_DESCRIPTORS) {
struct imxdma_desc *desc;
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
if (!desc)
break;
__memzero(&desc->desc, sizeof(struct dma_async_tx_descriptor));
dma_async_tx_descriptor_init(&desc->desc, chan);
desc->desc.tx_submit = imxdma_tx_submit;
/* txd.flags will be overwritten in prep funcs */
desc->desc.flags = DMA_CTRL_ACK;
desc->status = DMA_SUCCESS;
list_add_tail(&desc->node, &imxdmac->ld_free);
imxdmac->descs_allocated++;
}
if (!imxdmac->descs_allocated)
return -ENOMEM;
return imxdmac->descs_allocated;
}
static void imxdma_free_chan_resources(struct dma_chan *chan)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_desc *desc, *_desc;
unsigned long flags;
spin_lock_irqsave(&imxdmac->lock, flags);
imx_dma_disable(imxdmac->imxdma_channel);
list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
spin_unlock_irqrestore(&imxdmac->lock, flags);
list_for_each_entry_safe(desc, _desc, &imxdmac->ld_free, node) {
kfree(desc);
imxdmac->descs_allocated--;
}
INIT_LIST_HEAD(&imxdmac->ld_free);
if (imxdmac->sg_list) {
kfree(imxdmac->sg_list);
imxdmac->sg_list = NULL;
}
}
static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct scatterlist *sg;
int i, dma_length = 0;
struct imxdma_desc *desc;
if (list_empty(&imxdmac->ld_free) ||
imxdma_chan_is_doing_cyclic(imxdmac))
return NULL;
desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
for_each_sg(sgl, sg, sg_len, i) {
dma_length += sg->length;
}
switch (imxdmac->word_size) {
case DMA_SLAVE_BUSWIDTH_4_BYTES:
if (sgl->length & 3 || sgl->dma_address & 3)
return NULL;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
if (sgl->length & 1 || sgl->dma_address & 1)
return NULL;
break;
case DMA_SLAVE_BUSWIDTH_1_BYTE:
break;
default:
return NULL;
}
desc->type = IMXDMA_DESC_SLAVE_SG;
desc->sg = sgl;
desc->sgcount = sg_len;
desc->len = dma_length;
if (direction == DMA_DEV_TO_MEM) {
desc->dmamode = DMA_MODE_READ;
desc->src = imxdmac->per_address;
} else {
desc->dmamode = DMA_MODE_WRITE;
desc->dest = imxdmac->per_address;
}
desc->desc.callback = NULL;
desc->desc.callback_param = NULL;
return &desc->desc;
}
static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_engine *imxdma = imxdmac->imxdma;
struct imxdma_desc *desc;
int i;
unsigned int periods = buf_len / period_len;
dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
__func__, imxdmac->channel, buf_len, period_len);
if (list_empty(&imxdmac->ld_free) ||
imxdma_chan_is_doing_cyclic(imxdmac))
return NULL;
desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
if (imxdmac->sg_list)
kfree(imxdmac->sg_list);
imxdmac->sg_list = kcalloc(periods + 1,
sizeof(struct scatterlist), GFP_KERNEL);
if (!imxdmac->sg_list)
return NULL;
sg_init_table(imxdmac->sg_list, periods);
for (i = 0; i < periods; i++) {
imxdmac->sg_list[i].page_link = 0;
imxdmac->sg_list[i].offset = 0;
imxdmac->sg_list[i].dma_address = dma_addr;
imxdmac->sg_list[i].length = period_len;
dma_addr += period_len;
}
/* close the loop */
imxdmac->sg_list[periods].offset = 0;
imxdmac->sg_list[periods].length = 0;
imxdmac->sg_list[periods].page_link =
((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;
desc->type = IMXDMA_DESC_CYCLIC;
desc->sg = imxdmac->sg_list;
desc->sgcount = periods;
desc->len = IMX_DMA_LENGTH_LOOP;
if (direction == DMA_DEV_TO_MEM) {
desc->dmamode = DMA_MODE_READ;
desc->src = imxdmac->per_address;
} else {
desc->dmamode = DMA_MODE_WRITE;
desc->dest = imxdmac->per_address;
}
desc->desc.callback = NULL;
desc->desc.callback_param = NULL;
return &desc->desc;
}
static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
struct dma_chan *chan, dma_addr_t dest,
dma_addr_t src, size_t len, unsigned long flags)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_engine *imxdma = imxdmac->imxdma;
struct imxdma_desc *desc;
dev_dbg(imxdma->dev, "%s channel: %d src=0x%x dst=0x%x len=%d\n",
__func__, imxdmac->channel, src, dest, len);
if (list_empty(&imxdmac->ld_free) ||
imxdma_chan_is_doing_cyclic(imxdmac))
return NULL;
desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
desc->type = IMXDMA_DESC_MEMCPY;
desc->src = src;
desc->dest = dest;
desc->len = len;
desc->dmamode = DMA_MODE_WRITE;
desc->config_port = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
desc->config_mem = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
desc->desc.callback = NULL;
desc->desc.callback_param = NULL;
return &desc->desc;
}
static void imxdma_issue_pending(struct dma_chan *chan)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_engine *imxdma = imxdmac->imxdma;
struct imxdma_desc *desc;
unsigned long flags;
spin_lock_irqsave(&imxdmac->lock, flags);
if (list_empty(&imxdmac->ld_active) &&
!list_empty(&imxdmac->ld_queue)) {
desc = list_first_entry(&imxdmac->ld_queue,
struct imxdma_desc, node);
if (imxdma_xfer_desc(desc) < 0) {
dev_warn(imxdma->dev,
"%s: channel: %d couldn't issue DMA xfer\n",
__func__, imxdmac->channel);
} else {
list_move_tail(imxdmac->ld_queue.next,
&imxdmac->ld_active);
}
}
spin_unlock_irqrestore(&imxdmac->lock, flags);
}
static int __init imxdma_probe(struct platform_device *pdev)
{
struct imxdma_engine *imxdma;
int ret, i;
imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
if (!imxdma)
return -ENOMEM;
INIT_LIST_HEAD(&imxdma->dma_device.channels);
dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
dma_cap_set(DMA_MEMCPY, imxdma->dma_device.cap_mask);
/* Initialize channel parameters */
for (i = 0; i < MAX_DMA_CHANNELS; i++) {
struct imxdma_channel *imxdmac = &imxdma->channel[i];
imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine",
DMA_PRIO_MEDIUM);
if ((int)imxdmac->channel < 0) {
ret = -ENODEV;
goto err_init;
}
imx_dma_setup_handlers(imxdmac->imxdma_channel,
imxdma_irq_handler, imxdma_err_handler, imxdmac);
imxdmac->imxdma = imxdma;
spin_lock_init(&imxdmac->lock);
INIT_LIST_HEAD(&imxdmac->ld_queue);
INIT_LIST_HEAD(&imxdmac->ld_free);
INIT_LIST_HEAD(&imxdmac->ld_active);
tasklet_init(&imxdmac->dma_tasklet, imxdma_tasklet,
(unsigned long)imxdmac);
imxdmac->chan.device = &imxdma->dma_device;
imxdmac->channel = i;
/* Add the channel to the DMAC list */
list_add_tail(&imxdmac->chan.device_node,
&imxdma->dma_device.channels);
}
imxdma->dev = &pdev->dev;
imxdma->dma_device.dev = &pdev->dev;
imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
imxdma->dma_device.device_tx_status = imxdma_tx_status;
imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
imxdma->dma_device.device_prep_dma_memcpy = imxdma_prep_dma_memcpy;
imxdma->dma_device.device_control = imxdma_control;
imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
platform_set_drvdata(pdev, imxdma);
imxdma->dma_device.copy_align = 2; /* 2^2 = 4 bytes alignment */
imxdma->dma_device.dev->dma_parms = &imxdma->dma_parms;
dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);
ret = dma_async_device_register(&imxdma->dma_device);
if (ret) {
dev_err(&pdev->dev, "unable to register\n");
goto err_init;
}
return 0;
err_init:
while (--i >= 0) {
struct imxdma_channel *imxdmac = &imxdma->channel[i];
imx_dma_free(imxdmac->imxdma_channel);
}
kfree(imxdma);
return ret;
}
static int __exit imxdma_remove(struct platform_device *pdev)
{
struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
int i;
dma_async_device_unregister(&imxdma->dma_device);
for (i = 0; i < MAX_DMA_CHANNELS; i++) {
struct imxdma_channel *imxdmac = &imxdma->channel[i];
imx_dma_free(imxdmac->imxdma_channel);
}
kfree(imxdma);
return 0;
}
static struct platform_driver imxdma_driver = {
.driver = {
.name = "imx-dma",
},
.remove = __exit_p(imxdma_remove),
};
static int __init imxdma_module_init(void)
{
return platform_driver_probe(&imxdma_driver, imxdma_probe);
}
subsys_initcall(imxdma_module_init);
MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("i.MX dma driver");
MODULE_LICENSE("GPL");