// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011 Broadcom Corporation. All rights reserved. */
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <sound/asoundef.h>
#include "bcm2835.h"
/* hardware definition */
static const struct snd_pcm_hardware snd_bcm2835_playback_hw = {
.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_SYNC_APPLPTR | SNDRV_PCM_INFO_BATCH),
.formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
.rate_min = 8000,
.rate_max = 192000,
.channels_min = 1,
.channels_max = 8,
.buffer_bytes_max = 512 * 1024,
.period_bytes_min = 1 * 1024,
.period_bytes_max = 512 * 1024,
.periods_min = 1,
.periods_max = 128,
};
static const struct snd_pcm_hardware snd_bcm2835_playback_spdif_hw = {
.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_SYNC_APPLPTR | SNDRV_PCM_INFO_BATCH),
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_44100 |
SNDRV_PCM_RATE_48000,
.rate_min = 44100,
.rate_max = 48000,
.channels_min = 2,
.channels_max = 2,
.buffer_bytes_max = 128 * 1024,
.period_bytes_min = 1 * 1024,
.period_bytes_max = 128 * 1024,
.periods_min = 1,
.periods_max = 128,
};
static void snd_bcm2835_playback_free(struct snd_pcm_runtime *runtime)
{
kfree(runtime->private_data);
}
void bcm2835_playback_fifo(struct bcm2835_alsa_stream *alsa_stream,
unsigned int bytes)
{
struct snd_pcm_substream *substream = alsa_stream->substream;
unsigned int pos;
if (!alsa_stream->period_size)
return;
if (bytes >= alsa_stream->buffer_size) {
snd_pcm_stream_lock(substream);
snd_pcm_stop(substream,
alsa_stream->draining ?
SNDRV_PCM_STATE_SETUP :
SNDRV_PCM_STATE_XRUN);
snd_pcm_stream_unlock(substream);
return;
}
pos = atomic_read(&alsa_stream->pos);
pos += bytes;
pos %= alsa_stream->buffer_size;
atomic_set(&alsa_stream->pos, pos);
alsa_stream->period_offset += bytes;
alsa_stream->interpolate_start = ktime_get();
if (alsa_stream->period_offset >= alsa_stream->period_size) {
alsa_stream->period_offset %= alsa_stream->period_size;
snd_pcm_period_elapsed(substream);
}
}
/* open callback */
static int snd_bcm2835_playback_open_generic(struct snd_pcm_substream *substream, int spdif)
{
struct bcm2835_chip *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream;
int idx;
int err;
mutex_lock(&chip->audio_mutex);
idx = substream->number;
if (spdif && chip->opened) {
err = -EBUSY;
goto out;
} else if (!spdif && (chip->opened & (1 << idx))) {
err = -EBUSY;
goto out;
}
if (idx >= MAX_SUBSTREAMS) {
dev_err(chip->dev,
"substream(%d) device doesn't exist max(%d) substreams allowed\n",
idx, MAX_SUBSTREAMS);
err = -ENODEV;
goto out;
}
alsa_stream = kzalloc(sizeof(*alsa_stream), GFP_KERNEL);
if (!alsa_stream) {
err = -ENOMEM;
goto out;
}
/* Initialise alsa_stream */
alsa_stream->chip = chip;
alsa_stream->substream = substream;
alsa_stream->idx = idx;
err = bcm2835_audio_open(alsa_stream);
if (err) {
kfree(alsa_stream);
goto out;
}
runtime->private_data = alsa_stream;
runtime->private_free = snd_bcm2835_playback_free;
if (spdif) {
runtime->hw = snd_bcm2835_playback_spdif_hw;
} else {
/* clear spdif status, as we are not in spdif mode */
chip->spdif_status = 0;
runtime->hw = snd_bcm2835_playback_hw;
}
/* minimum 16 bytes alignment (for vchiq bulk transfers) */
snd_pcm_hw_constraint_step(runtime,
0,
SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
16);
/* position update is in 10ms order */
snd_pcm_hw_constraint_minmax(runtime,
SNDRV_PCM_HW_PARAM_PERIOD_TIME,
10 * 1000, UINT_MAX);
chip->alsa_stream[idx] = alsa_stream;
chip->opened |= (1 << idx);
out:
mutex_unlock(&chip->audio_mutex);
return err;
}
static int snd_bcm2835_playback_open(struct snd_pcm_substream *substream)
{
return snd_bcm2835_playback_open_generic(substream, 0);
}
static int snd_bcm2835_playback_spdif_open(struct snd_pcm_substream *substream)
{
return snd_bcm2835_playback_open_generic(substream, 1);
}
static int snd_bcm2835_playback_close(struct snd_pcm_substream *substream)
{
struct bcm2835_alsa_stream *alsa_stream;
struct snd_pcm_runtime *runtime;
struct bcm2835_chip *chip;
chip = snd_pcm_substream_chip(substream);
mutex_lock(&chip->audio_mutex);
runtime = substream->runtime;
alsa_stream = runtime->private_data;
alsa_stream->period_size = 0;
alsa_stream->buffer_size = 0;
bcm2835_audio_close(alsa_stream);
alsa_stream->chip->alsa_stream[alsa_stream->idx] = NULL;
/*
* Do not free up alsa_stream here, it will be freed up by
* runtime->private_free callback we registered in *_open above
*/
chip->opened &= ~(1 << substream->number);
mutex_unlock(&chip->audio_mutex);
return 0;
}
static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
{
struct bcm2835_chip *chip = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
int channels;
int err;
/* notify the vchiq that it should enter spdif passthrough mode by
* setting channels=0 (see
* https://github.com/raspberrypi/linux/issues/528)
*/
if (chip->spdif_status & IEC958_AES0_NONAUDIO)
channels = 0;
else
channels = runtime->channels;
err = bcm2835_audio_set_params(alsa_stream, channels,
runtime->rate,
snd_pcm_format_width(runtime->format));
if (err < 0)
return err;
memset(&alsa_stream->pcm_indirect, 0, sizeof(alsa_stream->pcm_indirect));
alsa_stream->pcm_indirect.hw_buffer_size =
alsa_stream->pcm_indirect.sw_buffer_size =
snd_pcm_lib_buffer_bytes(substream);
alsa_stream->buffer_size = snd_pcm_lib_buffer_bytes(substream);
alsa_stream->period_size = snd_pcm_lib_period_bytes(substream);
atomic_set(&alsa_stream->pos, 0);
alsa_stream->period_offset = 0;
alsa_stream->draining = false;
alsa_stream->interpolate_start = ktime_get();
return 0;
}
static void snd_bcm2835_pcm_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect *rec, size_t bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
void *src = (void *)(substream->runtime->dma_area + rec->sw_data);
bcm2835_audio_write(alsa_stream, bytes, src);
}
static int snd_bcm2835_pcm_ack(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
struct snd_pcm_indirect *pcm_indirect = &alsa_stream->pcm_indirect;
return snd_pcm_indirect_playback_transfer(substream, pcm_indirect,
snd_bcm2835_pcm_transfer);
}
/* trigger callback */
static int snd_bcm2835_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
return bcm2835_audio_start(alsa_stream);
case SNDRV_PCM_TRIGGER_DRAIN:
alsa_stream->draining = true;
return bcm2835_audio_drain(alsa_stream);
case SNDRV_PCM_TRIGGER_STOP:
return bcm2835_audio_stop(alsa_stream);
default:
return -EINVAL;
}
}
/* pointer callback */
static snd_pcm_uframes_t
snd_bcm2835_pcm_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
ktime_t now = ktime_get();
/* Give userspace better delay reporting by interpolating between GPU
* notifications, assuming audio speed is close enough to the clock
* used for ktime
*/
if ((ktime_to_ns(alsa_stream->interpolate_start)) &&
(ktime_compare(alsa_stream->interpolate_start, now) < 0)) {
u64 interval =
(ktime_to_ns(ktime_sub(now,
alsa_stream->interpolate_start)));
u64 frames_output_in_interval =
div_u64((interval * runtime->rate), 1000000000);
snd_pcm_sframes_t frames_output_in_interval_sized =
-frames_output_in_interval;
runtime->delay = frames_output_in_interval_sized;
}
return snd_pcm_indirect_playback_pointer(substream,
&alsa_stream->pcm_indirect,
atomic_read(&alsa_stream->pos));
}
/* operators */
static const struct snd_pcm_ops snd_bcm2835_playback_ops = {
.open = snd_bcm2835_playback_open,
.close = snd_bcm2835_playback_close,
.prepare = snd_bcm2835_pcm_prepare,
.trigger = snd_bcm2835_pcm_trigger,
.pointer = snd_bcm2835_pcm_pointer,
.ack = snd_bcm2835_pcm_ack,
};
static const struct snd_pcm_ops snd_bcm2835_playback_spdif_ops = {
.open = snd_bcm2835_playback_spdif_open,
.close = snd_bcm2835_playback_close,
.prepare = snd_bcm2835_pcm_prepare,
.trigger = snd_bcm2835_pcm_trigger,
.pointer = snd_bcm2835_pcm_pointer,
.ack = snd_bcm2835_pcm_ack,
};
/* create a pcm device */
int snd_bcm2835_new_pcm(struct bcm2835_chip *chip, const char *name,
int idx, enum snd_bcm2835_route route,
u32 numchannels, bool spdif)
{
struct snd_pcm *pcm;
int err;
err = snd_pcm_new(chip->card, name, idx, numchannels, 0, &pcm);
if (err)
return err;
pcm->private_data = chip;
pcm->nonatomic = true;
strscpy(pcm->name, name, sizeof(pcm->name));
if (!spdif) {
chip->dest = route;
chip->volume = 0;
chip->mute = CTRL_VOL_UNMUTE;
}
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
spdif ? &snd_bcm2835_playback_spdif_ops :
&snd_bcm2835_playback_ops);
snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
chip->card->dev, 128 * 1024, 128 * 1024);
if (spdif)
chip->pcm_spdif = pcm;
else
chip->pcm = pcm;
return 0;
}
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