dma-ops.c
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/* linux/arch/arm/plat-samsung/dma-ops.c
*
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* Samsung DMA Operations
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/amba/pl330.h>
#include <linux/scatterlist.h>
#include <linux/export.h>
#include <mach/dma.h>
static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
struct samsung_dma_info *info)
{
struct dma_chan *chan;
dma_cap_mask_t mask;
struct dma_slave_config slave_config;
void *filter_param;
dma_cap_zero(mask);
dma_cap_set(info->cap, mask);
/*
* If a dma channel property of a device node from device tree is
* specified, use that as the fliter parameter.
*/
filter_param = (dma_ch == DMACH_DT_PROP) ? (void *)info->dt_dmach_prop :
(void *)dma_ch;
chan = dma_request_channel(mask, pl330_filter, filter_param);
if (info->direction == DMA_FROM_DEVICE) {
memset(&slave_config, 0, sizeof(struct dma_slave_config));
slave_config.direction = info->direction;
slave_config.src_addr = info->fifo;
slave_config.src_addr_width = info->width;
slave_config.src_maxburst = 1;
dmaengine_slave_config(chan, &slave_config);
} else if (info->direction == DMA_TO_DEVICE) {
memset(&slave_config, 0, sizeof(struct dma_slave_config));
slave_config.direction = info->direction;
slave_config.dst_addr = info->fifo;
slave_config.dst_addr_width = info->width;
slave_config.dst_maxburst = 1;
dmaengine_slave_config(chan, &slave_config);
}
return (unsigned)chan;
}
static int samsung_dmadev_release(unsigned ch,
struct s3c2410_dma_client *client)
{
dma_release_channel((struct dma_chan *)ch);
return 0;
}
static int samsung_dmadev_prepare(unsigned ch,
struct samsung_dma_prep_info *info)
{
struct scatterlist sg;
struct dma_chan *chan = (struct dma_chan *)ch;
struct dma_async_tx_descriptor *desc;
switch (info->cap) {
case DMA_SLAVE:
sg_init_table(&sg, 1);
sg_dma_len(&sg) = info->len;
sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)),
info->len, offset_in_page(info->buf));
sg_dma_address(&sg) = info->buf;
desc = chan->device->device_prep_slave_sg(chan,
&sg, 1, info->direction, DMA_PREP_INTERRUPT);
break;
case DMA_CYCLIC:
desc = chan->device->device_prep_dma_cyclic(chan,
info->buf, info->len, info->period, info->direction);
break;
default:
dev_err(&chan->dev->device, "unsupported format\n");
return -EFAULT;
}
if (!desc) {
dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
return -EFAULT;
}
desc->callback = info->fp;
desc->callback_param = info->fp_param;
dmaengine_submit((struct dma_async_tx_descriptor *)desc);
return 0;
}
static inline int samsung_dmadev_trigger(unsigned ch)
{
dma_async_issue_pending((struct dma_chan *)ch);
return 0;
}
static inline int samsung_dmadev_flush(unsigned ch)
{
return dmaengine_terminate_all((struct dma_chan *)ch);
}
struct samsung_dma_ops dmadev_ops = {
.request = samsung_dmadev_request,
.release = samsung_dmadev_release,
.prepare = samsung_dmadev_prepare,
.trigger = samsung_dmadev_trigger,
.started = NULL,
.flush = samsung_dmadev_flush,
.stop = samsung_dmadev_flush,
};
void *samsung_dmadev_get_ops(void)
{
return &dmadev_ops;
}
EXPORT_SYMBOL(samsung_dmadev_get_ops);