// SPDX-License-Identifier: GPL-2.0-or-later
/*
* sh_dac_audio.c - SuperH DAC audio driver for ALSA
*
* Copyright (c) 2009 by Rafael Ignacio Zurita <[email protected]>
*
* Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
*/
#include <linux/hrtimer.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/sh_dac_audio.h>
#include <asm/clock.h>
#include <asm/hd64461.h>
#include <mach/hp6xx.h>
#include <cpu/dac.h>
MODULE_AUTHOR("Rafael Ignacio Zurita <[email protected]>");
MODULE_DESCRIPTION("SuperH DAC audio driver");
MODULE_LICENSE("GPL");
/* Module Parameters */
static int index = SNDRV_DEFAULT_IDX1;
static char *id = SNDRV_DEFAULT_STR1;
module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
/* main struct */
struct snd_sh_dac {
struct snd_card *card;
struct snd_pcm_substream *substream;
struct hrtimer hrtimer;
ktime_t wakeups_per_second;
int rate;
int empty;
char *data_buffer, *buffer_begin, *buffer_end;
int processed; /* bytes proccesed, to compare with period_size */
int buffer_size;
struct dac_audio_pdata *pdata;
};
static void dac_audio_start_timer(struct snd_sh_dac *chip)
{
hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
HRTIMER_MODE_REL);
}
static void dac_audio_stop_timer(struct snd_sh_dac *chip)
{
hrtimer_cancel(&chip->hrtimer);
}
static void dac_audio_reset(struct snd_sh_dac *chip)
{
dac_audio_stop_timer(chip);
chip->buffer_begin = chip->buffer_end = chip->data_buffer;
chip->processed = 0;
chip->empty = 1;
}
static void dac_audio_set_rate(struct snd_sh_dac *chip)
{
chip->wakeups_per_second = 1000000000 / chip->rate;
}
/* PCM INTERFACE */
static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
.info = (SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_HALF_DUPLEX),
.formats = SNDRV_PCM_FMTBIT_U8,
.rates = SNDRV_PCM_RATE_8000,
.rate_min = 8000,
.rate_max = 8000,
.channels_min = 1,
.channels_max = 1,
.buffer_bytes_max = (48*1024),
.period_bytes_min = 1,
.period_bytes_max = (48*1024),
.periods_min = 1,
.periods_max = 1024,
};
static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
runtime->hw = snd_sh_dac_pcm_hw;
chip->substream = substream;
chip->buffer_begin = chip->buffer_end = chip->data_buffer;
chip->processed = 0;
chip->empty = 1;
chip->pdata->start(chip->pdata);
return 0;
}
static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
chip->substream = NULL;
dac_audio_stop_timer(chip);
chip->pdata->stop(chip->pdata);
return 0;
}
static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = chip->substream->runtime;
chip->buffer_size = runtime->buffer_size;
memset(chip->data_buffer, 0, chip->pdata->buffer_size);
return 0;
}
static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
dac_audio_start_timer(chip);
break;
case SNDRV_PCM_TRIGGER_STOP:
chip->buffer_begin = chip->buffer_end = chip->data_buffer;
chip->processed = 0;
chip->empty = 1;
dac_audio_stop_timer(chip);
break;
default:
return -EINVAL;
}
return 0;
}
static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
int channel, unsigned long pos,
struct iov_iter *src, unsigned long count)
{
/* channel is not used (interleaved data) */
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
if (copy_from_iter_toio(chip->data_buffer + pos, src, count))
return -EFAULT;
chip->buffer_end = chip->data_buffer + pos + count;
if (chip->empty) {
chip->empty = 0;
dac_audio_start_timer(chip);
}
return 0;
}
static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
int channel, unsigned long pos,
unsigned long count)
{
/* channel is not used (interleaved data) */
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
memset_io(chip->data_buffer + pos, 0, count);
chip->buffer_end = chip->data_buffer + pos + count;
if (chip->empty) {
chip->empty = 0;
dac_audio_start_timer(chip);
}
return 0;
}
static
snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
{
struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
int pointer = chip->buffer_begin - chip->data_buffer;
return pointer;
}
/* pcm ops */
static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
.open = snd_sh_dac_pcm_open,
.close = snd_sh_dac_pcm_close,
.prepare = snd_sh_dac_pcm_prepare,
.trigger = snd_sh_dac_pcm_trigger,
.pointer = snd_sh_dac_pcm_pointer,
.copy = snd_sh_dac_pcm_copy,
.fill_silence = snd_sh_dac_pcm_silence,
.mmap = snd_pcm_lib_mmap_iomem,
};
static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
{
int err;
struct snd_pcm *pcm;
/* device should be always 0 for us */
err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
if (err < 0)
return err;
pcm->private_data = chip;
strcpy(pcm->name, "SH_DAC PCM");
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
/* buffer size=48K */
snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
NULL, 48 * 1024, 48 * 1024);
return 0;
}
/* END OF PCM INTERFACE */
/* driver .remove -- destructor */
static void snd_sh_dac_remove(struct platform_device *devptr)
{
snd_card_free(platform_get_drvdata(devptr));
}
/* free -- it has been defined by create */
static int snd_sh_dac_free(struct snd_sh_dac *chip)
{
/* release the data */
kfree(chip->data_buffer);
kfree(chip);
return 0;
}
static int snd_sh_dac_dev_free(struct snd_device *device)
{
struct snd_sh_dac *chip = device->device_data;
return snd_sh_dac_free(chip);
}
static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
{
struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
hrtimer);
struct snd_pcm_runtime *runtime = chip->substream->runtime;
ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
if (!chip->empty) {
sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
chip->buffer_begin++;
chip->processed++;
if (chip->processed >= b_ps) {
chip->processed -= b_ps;
snd_pcm_period_elapsed(chip->substream);
}
if (chip->buffer_begin == (chip->data_buffer +
chip->buffer_size - 1))
chip->buffer_begin = chip->data_buffer;
if (chip->buffer_begin == chip->buffer_end)
chip->empty = 1;
}
if (!chip->empty)
hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
HRTIMER_MODE_REL);
return HRTIMER_NORESTART;
}
/* create -- chip-specific constructor for the cards components */
static int snd_sh_dac_create(struct snd_card *card,
struct platform_device *devptr,
struct snd_sh_dac **rchip)
{
struct snd_sh_dac *chip;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_sh_dac_dev_free,
};
*rchip = NULL;
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
chip->card = card;
hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
chip->hrtimer.function = sh_dac_audio_timer;
dac_audio_reset(chip);
chip->rate = 8000;
dac_audio_set_rate(chip);
chip->pdata = devptr->dev.platform_data;
chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
if (chip->data_buffer == NULL) {
kfree(chip);
return -ENOMEM;
}
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
if (err < 0) {
snd_sh_dac_free(chip);
return err;
}
*rchip = chip;
return 0;
}
/* driver .probe -- constructor */
static int snd_sh_dac_probe(struct platform_device *devptr)
{
struct snd_sh_dac *chip;
struct snd_card *card;
int err;
err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
if (err < 0) {
dev_err(&devptr->dev, "cannot allocate the card\n");
return err;
}
err = snd_sh_dac_create(card, devptr, &chip);
if (err < 0)
goto probe_error;
err = snd_sh_dac_pcm(chip, 0);
if (err < 0)
goto probe_error;
strcpy(card->driver, "snd_sh_dac");
strcpy(card->shortname, "SuperH DAC audio driver");
dev_info(&devptr->dev, "%s %s\n", card->longname, card->shortname);
err = snd_card_register(card);
if (err < 0)
goto probe_error;
dev_info(&devptr->dev, "ALSA driver for SuperH DAC audio\n");
platform_set_drvdata(devptr, card);
return 0;
probe_error:
snd_card_free(card);
return err;
}
/*
* "driver" definition
*/
static struct platform_driver sh_dac_driver = {
.probe = snd_sh_dac_probe,
.remove_new = snd_sh_dac_remove,
.driver = {
.name = "dac_audio",
},
};
module_platform_driver(sh_dac_driver);
Codebase Browser
linux