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/*
* 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>
*
* 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/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>
struct imxdma_channel {
struct imxdma_engine *imxdma;
unsigned int channel;
unsigned int imxdma_channel;
enum dma_slave_buswidth word_size;
dma_addr_t per_address;
u32 watermark_level;
struct dma_chan chan;
spinlock_t lock;
struct dma_async_tx_descriptor desc;
dma_cookie_t last_completed;
enum dma_status status;
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 void imxdma_handle(struct imxdma_channel *imxdmac)
{
if (imxdmac->desc.callback)
imxdmac->desc.callback(imxdmac->desc.callback_param);
imxdmac->last_completed = imxdmac->desc.cookie;
}
static void imxdma_irq_handler(int channel, void *data)
{
struct imxdma_channel *imxdmac = data;
imxdmac->status = DMA_SUCCESS;
imxdma_handle(imxdmac);
}
static void imxdma_err_handler(int channel, void *data, int error)
{
struct imxdma_channel *imxdmac = data;
imxdmac->status = DMA_ERROR;
imxdma_handle(imxdmac);
}
static void imxdma_progression(int channel, void *data,
struct scatterlist *sg)
{
struct imxdma_channel *imxdmac = data;
imxdmac->status = DMA_SUCCESS;
imxdma_handle(imxdmac);
}
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 int mode = 0;
switch (cmd) {
case DMA_TERMINATE_ALL:
imxdmac->status = DMA_ERROR;
imx_dma_disable(imxdmac->imxdma_channel);
return 0;
case DMA_SLAVE_CONFIG:
if (dmaengine_cfg->direction == DMA_FROM_DEVICE) {
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);
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;
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);
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;
imxdma->desc.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;
spin_lock_irq(&imxdmac->lock);
cookie = imxdma_assign_cookie(imxdmac);
imx_dma_enable(imxdmac->imxdma_channel);
spin_unlock_irq(&imxdmac->lock);
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;
imxdmac->dma_request = data->dma_request;
dma_async_tx_descriptor_init(&imxdmac->desc, chan);
imxdmac->desc.tx_submit = imxdma_tx_submit;
/* txd.flags will be overwritten in prep funcs */
imxdmac->desc.flags = DMA_CTRL_ACK;
imxdmac->status = DMA_SUCCESS;
return 0;
}
static void imxdma_free_chan_resources(struct dma_chan *chan)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
imx_dma_disable(imxdmac->imxdma_channel);
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_data_direction direction,
unsigned long flags)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct scatterlist *sg;
int i, ret, dma_length = 0;
unsigned int dmamode;
if (imxdmac->status == DMA_IN_PROGRESS)
return NULL;
imxdmac->status = DMA_IN_PROGRESS;
for_each_sg(sgl, sg, sg_len, i) {
dma_length += sg->length;
}
if (direction == DMA_FROM_DEVICE)
dmamode = DMA_MODE_READ;
else
dmamode = DMA_MODE_WRITE;
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;
}
ret = imx_dma_setup_sg(imxdmac->imxdma_channel, sgl, sg_len,
dma_length, imxdmac->per_address, dmamode);
if (ret)
return NULL;
return &imxdmac->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_data_direction direction)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_engine *imxdma = imxdmac->imxdma;
int i, ret;
unsigned int periods = buf_len / period_len;
unsigned int dmamode;
dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
__func__, imxdmac->channel, buf_len, period_len);
if (imxdmac->status == DMA_IN_PROGRESS)
return NULL;
imxdmac->status = DMA_IN_PROGRESS;
ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
imxdma_progression);
if (ret) {
dev_err(imxdma->dev, "Failed to setup the DMA handler\n");
return NULL;
}
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;
if (direction == DMA_FROM_DEVICE)
dmamode = DMA_MODE_READ;
else
dmamode = DMA_MODE_WRITE;
ret = imx_dma_setup_sg(imxdmac->imxdma_channel, imxdmac->sg_list, periods,
IMX_DMA_LENGTH_LOOP, imxdmac->per_address, dmamode);
if (ret)
return NULL;
return &imxdmac->desc;
}
static void imxdma_issue_pending(struct dma_chan *chan)
{
/*
* Nothing to do. We only have a single descriptor
*/
}
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);
/* 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);
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_control = imxdma_control;
imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
platform_set_drvdata(pdev, imxdma);
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");