/*
* omap-pcm.c -- ALSA PCM interface for the OMAP SoC
*
* Copyright (C) 2008 Nokia Corporation
*
* Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/dma-mapping.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <asm/arch/dma.h>
#include "omap-pcm.h"
static const struct snd_pcm_hardware omap_pcm_hardware = {
.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_PAUSE |
SNDRV_PCM_INFO_RESUME,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.period_bytes_min = 32,
.period_bytes_max = 64 * 1024,
.periods_min = 2,
.periods_max = 255,
.buffer_bytes_max = 128 * 1024,
};
struct omap_runtime_data {
spinlock_t lock;
struct omap_pcm_dma_data *dma_data;
int dma_ch;
int period_index;
};
static void omap_pcm_dma_irq(int ch, u16 stat, void *data)
{
struct snd_pcm_substream *substream = data;
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
unsigned long flags;
if (cpu_is_omap1510()) {
/*
* OMAP1510 doesn't support DMA chaining so have to restart
* the transfer after all periods are transferred
*/
spin_lock_irqsave(&prtd->lock, flags);
if (prtd->period_index >= 0) {
if (++prtd->period_index == runtime->periods) {
prtd->period_index = 0;
omap_start_dma(prtd->dma_ch);
}
}
spin_unlock_irqrestore(&prtd->lock, flags);
}
snd_pcm_period_elapsed(substream);
}
/* this may get called several times by oss emulation */
static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct omap_runtime_data *prtd = runtime->private_data;
struct omap_pcm_dma_data *dma_data = rtd->dai->cpu_dai->dma_data;
int err = 0;
if (!dma_data)
return -ENODEV;
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
runtime->dma_bytes = params_buffer_bytes(params);
if (prtd->dma_data)
return 0;
prtd->dma_data = dma_data;
err = omap_request_dma(dma_data->dma_req, dma_data->name,
omap_pcm_dma_irq, substream, &prtd->dma_ch);
if (!cpu_is_omap1510()) {
/*
* Link channel with itself so DMA doesn't need any
* reprogramming while looping the buffer
*/
omap_dma_link_lch(prtd->dma_ch, prtd->dma_ch);
}
return err;
}
static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
if (prtd->dma_data == NULL)
return 0;
if (!cpu_is_omap1510())
omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
omap_free_dma(prtd->dma_ch);
prtd->dma_data = NULL;
snd_pcm_set_runtime_buffer(substream, NULL);
return 0;
}
static int omap_pcm_prepare(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
struct omap_pcm_dma_data *dma_data = prtd->dma_data;
struct omap_dma_channel_params dma_params;
memset(&dma_params, 0, sizeof(dma_params));
/*
* Note: Regardless of interface data formats supported by OMAP McBSP
* or EAC blocks, internal representation is always fixed 16-bit/sample
*/
dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
dma_params.trigger = dma_data->dma_req;
dma_params.sync_mode = OMAP_DMA_SYNC_ELEMENT;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
dma_params.src_amode = OMAP_DMA_AMODE_POST_INC;
dma_params.dst_amode = OMAP_DMA_AMODE_CONSTANT;
dma_params.src_or_dst_synch = OMAP_DMA_DST_SYNC;
dma_params.src_start = runtime->dma_addr;
dma_params.dst_start = dma_data->port_addr;
} else {
dma_params.src_amode = OMAP_DMA_AMODE_CONSTANT;
dma_params.dst_amode = OMAP_DMA_AMODE_POST_INC;
dma_params.src_or_dst_synch = OMAP_DMA_SRC_SYNC;
dma_params.src_start = dma_data->port_addr;
dma_params.dst_start = runtime->dma_addr;
}
/*
* Set DMA transfer frame size equal to ALSA period size and frame
* count as no. of ALSA periods. Then with DMA frame interrupt enabled,
* we can transfer the whole ALSA buffer with single DMA transfer but
* still can get an interrupt at each period bounary
*/
dma_params.elem_count = snd_pcm_lib_period_bytes(substream) / 2;
dma_params.frame_count = runtime->periods;
omap_set_dma_params(prtd->dma_ch, &dma_params);
omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ);
return 0;
}
static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
int ret = 0;
spin_lock_irq(&prtd->lock);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
prtd->period_index = 0;
omap_start_dma(prtd->dma_ch);
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
prtd->period_index = -1;
omap_stop_dma(prtd->dma_ch);
break;
default:
ret = -EINVAL;
}
spin_unlock_irq(&prtd->lock);
return ret;
}
static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd = runtime->private_data;
dma_addr_t ptr;
snd_pcm_uframes_t offset;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
ptr = omap_get_dma_src_pos(prtd->dma_ch);
else
ptr = omap_get_dma_dst_pos(prtd->dma_ch);
offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
if (offset >= runtime->buffer_size)
offset = 0;
return offset;
}
static int omap_pcm_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct omap_runtime_data *prtd;
int ret;
snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);
/* Ensure that buffer size is a multiple of period size */
ret = snd_pcm_hw_constraint_integer(runtime,
SNDRV_PCM_HW_PARAM_PERIODS);
if (ret < 0)
goto out;
prtd = kzalloc(sizeof(prtd), GFP_KERNEL);
if (prtd == NULL) {
ret = -ENOMEM;
goto out;
}
spin_lock_init(&prtd->lock);
runtime->private_data = prtd;
out:
return ret;
}
static int omap_pcm_close(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
kfree(runtime->private_data);
return 0;
}
static int omap_pcm_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return dma_mmap_writecombine(substream->pcm->card->dev, vma,
runtime->dma_area,
runtime->dma_addr,
runtime->dma_bytes);
}
struct snd_pcm_ops omap_pcm_ops = {
.open = omap_pcm_open,
.close = omap_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = omap_pcm_hw_params,
.hw_free = omap_pcm_hw_free,
.prepare = omap_pcm_prepare,
.trigger = omap_pcm_trigger,
.pointer = omap_pcm_pointer,
.mmap = omap_pcm_mmap,
};
static u64 omap_pcm_dmamask = DMA_BIT_MASK(32);
static int omap_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
size_t size = omap_pcm_hardware.buffer_bytes_max;
buf->dev.type = SNDRV_DMA_TYPE_DEV;
buf->dev.dev = pcm->card->dev;
buf->private_data = NULL;
buf->area = dma_alloc_writecombine(pcm->card->dev, size,
&buf->addr, GFP_KERNEL);
if (!buf->area)
return -ENOMEM;
buf->bytes = size;
return 0;
}
static void omap_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
int stream;
for (stream = 0; stream < 2; stream++) {
substream = pcm->streams[stream].substream;
if (!substream)
continue;
buf = &substream->dma_buffer;
if (!buf->area)
continue;
dma_free_writecombine(pcm->card->dev, buf->bytes,
buf->area, buf->addr);
buf->area = NULL;
}
}
int omap_pcm_new(struct snd_card *card, struct snd_soc_codec_dai *dai,
struct snd_pcm *pcm)
{
int ret = 0;
if (!card->dev->dma_mask)
card->dev->dma_mask = &omap_pcm_dmamask;
if (!card->dev->coherent_dma_mask)
card->dev->coherent_dma_mask = DMA_32BIT_MASK;
if (dai->playback.channels_min) {
ret = omap_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
if (ret)
goto out;
}
if (dai->capture.channels_min) {
ret = omap_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_CAPTURE);
if (ret)
goto out;
}
out:
return ret;
}
struct snd_soc_platform omap_soc_platform = {
.name = "omap-pcm-audio",
.pcm_ops = &omap_pcm_ops,
.pcm_new = omap_pcm_new,
.pcm_free = omap_pcm_free_dma_buffers,
};
EXPORT_SYMBOL_GPL(omap_soc_platform);
MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@nokia.com>");
MODULE_DESCRIPTION("OMAP PCM DMA module");
MODULE_LICENSE("GPL");
