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DEFINITIONS
This source file includes following definitions.
- at91_pcm_dma_irq
- at91_pcm_hw_params
- at91_pcm_hw_free
- at91_pcm_prepare
- at91_pcm_trigger
- at91_pcm_pointer
- at91_pcm_open
- at91_pcm_close
- at91_pcm_mmap
- at91_pcm_preallocate_dma_buffer
- at91_pcm_new
- at91_pcm_free_dma_buffers
- at91_pcm_suspend
- at91_pcm_resume
/*
* at91-pcm.c -- ALSA PCM interface for the Atmel AT91 SoC
*
* Author: Frank Mandarino <fmandarino@endrelia.com>
* Endrelia Technologies Inc.
* Created: Mar 3, 2006
*
* Based on pxa2xx-pcm.c by:
*
* Author: Nicolas Pitre
* Created: Nov 30, 2004
* Copyright: (C) 2004 MontaVista Software, Inc.
*
* 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/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/atmel_pdc.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <mach/hardware.h>
#include <mach/at91_ssc.h>
#include "at91-pcm.h"
#if 0
#define DBG(x...) printk(KERN_INFO "at91-pcm: " x)
#else
#define DBG(x...)
#endif
static const struct snd_pcm_hardware at91_pcm_hardware = {
.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_PAUSE,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.period_bytes_min = 32,
.period_bytes_max = 8192,
.periods_min = 2,
.periods_max = 1024,
.buffer_bytes_max = 32 * 1024,
};
struct at91_runtime_data {
struct at91_pcm_dma_params *params;
dma_addr_t dma_buffer; /* physical address of dma buffer */
dma_addr_t dma_buffer_end; /* first address beyond DMA buffer */
size_t period_size;
dma_addr_t period_ptr; /* physical address of next period */
u32 pdc_xpr_save; /* PDC register save */
u32 pdc_xcr_save;
u32 pdc_xnpr_save;
u32 pdc_xncr_save;
};
static void at91_pcm_dma_irq(u32 ssc_sr,
struct snd_pcm_substream *substream)
{
struct at91_runtime_data *prtd = substream->runtime->private_data;
struct at91_pcm_dma_params *params = prtd->params;
static int count = 0;
count++;
if (ssc_sr & params->mask->ssc_endbuf) {
printk(KERN_WARNING
"at91-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
substream->stream == SNDRV_PCM_STREAM_PLAYBACK
? "underrun" : "overrun",
params->name, ssc_sr, count);
/* re-start the PDC */
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
prtd->period_ptr += prtd->period_size;
if (prtd->period_ptr >= prtd->dma_buffer_end) {
prtd->period_ptr = prtd->dma_buffer;
}
at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->period_ptr);
at91_ssc_write(params->ssc_base + params->pdc->xcr,
prtd->period_size / params->pdc_xfer_size);
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
}
if (ssc_sr & params->mask->ssc_endx) {
/* Load the PDC next pointer and counter registers */
prtd->period_ptr += prtd->period_size;
if (prtd->period_ptr >= prtd->dma_buffer_end) {
prtd->period_ptr = prtd->dma_buffer;
}
at91_ssc_write(params->ssc_base + params->pdc->xnpr,
prtd->period_ptr);
at91_ssc_write(params->ssc_base + params->pdc->xncr,
prtd->period_size / params->pdc_xfer_size);
}
snd_pcm_period_elapsed(substream);
}
static int at91_pcm_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct at91_runtime_data *prtd = runtime->private_data;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
/* this may get called several times by oss emulation
* with different params */
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
runtime->dma_bytes = params_buffer_bytes(params);
prtd->params = rtd->dai->cpu_dai->dma_data;
prtd->params->dma_intr_handler = at91_pcm_dma_irq;
prtd->dma_buffer = runtime->dma_addr;
prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
prtd->period_size = params_period_bytes(params);
DBG("hw_params: DMA for %s initialized (dma_bytes=%d, period_size=%d)\n",
prtd->params->name, runtime->dma_bytes, prtd->period_size);
return 0;
}
static int at91_pcm_hw_free(struct snd_pcm_substream *substream)
{
struct at91_runtime_data *prtd = substream->runtime->private_data;
struct at91_pcm_dma_params *params = prtd->params;
if (params != NULL) {
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
prtd->params->dma_intr_handler = NULL;
}
return 0;
}
static int at91_pcm_prepare(struct snd_pcm_substream *substream)
{
struct at91_runtime_data *prtd = substream->runtime->private_data;
struct at91_pcm_dma_params *params = prtd->params;
at91_ssc_write(params->ssc_base + AT91_SSC_IDR,
params->mask->ssc_endx | params->mask->ssc_endbuf);
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
return 0;
}
static int at91_pcm_trigger(struct snd_pcm_substream *substream,
int cmd)
{
struct at91_runtime_data *prtd = substream->runtime->private_data;
struct at91_pcm_dma_params *params = prtd->params;
int ret = 0;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
prtd->period_ptr = prtd->dma_buffer;
at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->period_ptr);
at91_ssc_write(params->ssc_base + params->pdc->xcr,
prtd->period_size / params->pdc_xfer_size);
prtd->period_ptr += prtd->period_size;
at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->period_ptr);
at91_ssc_write(params->ssc_base + params->pdc->xncr,
prtd->period_size / params->pdc_xfer_size);
DBG("trigger: period_ptr=%lx, xpr=%lx, xcr=%ld, xnpr=%lx, xncr=%ld\n",
(unsigned long) prtd->period_ptr,
at91_ssc_read(params->ssc_base + params->pdc->xpr),
at91_ssc_read(params->ssc_base + params->pdc->xcr),
at91_ssc_read(params->ssc_base + params->pdc->xnpr),
at91_ssc_read(params->ssc_base + params->pdc->xncr));
at91_ssc_write(params->ssc_base + AT91_SSC_IER,
params->mask->ssc_endx | params->mask->ssc_endbuf);
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR,
params->mask->pdc_enable);
DBG("sr=%lx imr=%lx\n",
at91_ssc_read(params->ssc_base + AT91_SSC_SR),
at91_ssc_read(params->ssc_base + AT91_SSC_IMR));
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
break;
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
break;
default:
ret = -EINVAL;
}
return ret;
}
static snd_pcm_uframes_t at91_pcm_pointer(
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct at91_runtime_data *prtd = runtime->private_data;
struct at91_pcm_dma_params *params = prtd->params;
dma_addr_t ptr;
snd_pcm_uframes_t x;
ptr = (dma_addr_t) at91_ssc_read(params->ssc_base + params->pdc->xpr);
x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
if (x == runtime->buffer_size)
x = 0;
return x;
}
static int at91_pcm_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct at91_runtime_data *prtd;
int ret = 0;
snd_soc_set_runtime_hwparams(substream, &at91_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(struct at91_runtime_data), GFP_KERNEL);
if (prtd == NULL) {
ret = -ENOMEM;
goto out;
}
runtime->private_data = prtd;
out:
return ret;
}
static int at91_pcm_close(struct snd_pcm_substream *substream)
{
struct at91_runtime_data *prtd = substream->runtime->private_data;
kfree(prtd);
return 0;
}
static int at91_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 at91_pcm_ops = {
.open = at91_pcm_open,
.close = at91_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = at91_pcm_hw_params,
.hw_free = at91_pcm_hw_free,
.prepare = at91_pcm_prepare,
.trigger = at91_pcm_trigger,
.pointer = at91_pcm_pointer,
.mmap = at91_pcm_mmap,
};
static int at91_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 = at91_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);
DBG("preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
(void *) buf->area,
(void *) buf->addr,
size);
if (!buf->area)
return -ENOMEM;
buf->bytes = size;
return 0;
}
static u64 at91_pcm_dmamask = 0xffffffff;
static int at91_pcm_new(struct snd_card *card,
struct snd_soc_dai *dai, struct snd_pcm *pcm)
{
int ret = 0;
if (!card->dev->dma_mask)
card->dev->dma_mask = &at91_pcm_dmamask;
if (!card->dev->coherent_dma_mask)
card->dev->coherent_dma_mask = 0xffffffff;
if (dai->playback.channels_min) {
ret = at91_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
if (ret)
goto out;
}
if (dai->capture.channels_min) {
ret = at91_pcm_preallocate_dma_buffer(pcm,
SNDRV_PCM_STREAM_CAPTURE);
if (ret)
goto out;
}
out:
return ret;
}
static void at91_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;
}
}
#ifdef CONFIG_PM
static int at91_pcm_suspend(struct platform_device *pdev,
struct snd_soc_dai *dai)
{
struct snd_pcm_runtime *runtime = dai->runtime;
struct at91_runtime_data *prtd;
struct at91_pcm_dma_params *params;
if (!runtime)
return 0;
prtd = runtime->private_data;
params = prtd->params;
/* disable the PDC and save the PDC registers */
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
prtd->pdc_xpr_save = at91_ssc_read(params->ssc_base + params->pdc->xpr);
prtd->pdc_xcr_save = at91_ssc_read(params->ssc_base + params->pdc->xcr);
prtd->pdc_xnpr_save = at91_ssc_read(params->ssc_base + params->pdc->xnpr);
prtd->pdc_xncr_save = at91_ssc_read(params->ssc_base + params->pdc->xncr);
return 0;
}
static int at91_pcm_resume(struct platform_device *pdev,
struct snd_soc_dai *dai)
{
struct snd_pcm_runtime *runtime = dai->runtime;
struct at91_runtime_data *prtd;
struct at91_pcm_dma_params *params;
if (!runtime)
return 0;
prtd = runtime->private_data;
params = prtd->params;
/* restore the PDC registers and enable the PDC */
at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->pdc_xpr_save);
at91_ssc_write(params->ssc_base + params->pdc->xcr, prtd->pdc_xcr_save);
at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->pdc_xnpr_save);
at91_ssc_write(params->ssc_base + params->pdc->xncr, prtd->pdc_xncr_save);
at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
return 0;
}
#else
#define at91_pcm_suspend NULL
#define at91_pcm_resume NULL
#endif
struct snd_soc_platform at91_soc_platform = {
.name = "at91-audio",
.pcm_ops = &at91_pcm_ops,
.pcm_new = at91_pcm_new,
.pcm_free = at91_pcm_free_dma_buffers,
.suspend = at91_pcm_suspend,
.resume = at91_pcm_resume,
};
EXPORT_SYMBOL_GPL(at91_soc_platform);
MODULE_AUTHOR("Frank Mandarino <fmandarino@endrelia.com>");
MODULE_DESCRIPTION("Atmel AT91 PCM module");
MODULE_LICENSE("GPL");