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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2021 StarFive Technology Co., Ltd.
*/
#include <linux/io.h>
#include <linux/rcupdate.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "pwmdac.h"
#define BUFFER_BYTES_MAX (3 * 2 * 8 * PERIOD_BYTES_MIN)
#define PERIOD_BYTES_MIN 4096
#define PERIODS_MIN 2
static unsigned int sf_pwmdac_pcm_tx_8(struct sf_pwmdac_dev *dev,
struct snd_pcm_runtime *runtime, unsigned int tx_ptr,
bool *period_elapsed)
{
const u8 (*p)[2] = (void *)runtime->dma_area;
unsigned int period_pos = tx_ptr % runtime->period_size;
int i;
u32 basedat = 0;
for (i = 0; i < dev->fifo_th; i++) {
basedat = (p[tx_ptr][0]<<8)|(p[tx_ptr][1] << 24);
iowrite32(basedat,dev->pwmdac_base + PWMDAC_WDATA);
period_pos++;
if (++tx_ptr >= runtime->buffer_size)
tx_ptr = 0;
}
*period_elapsed = period_pos >= runtime->period_size;
return tx_ptr;
}
static unsigned int sf_pwmdac_pcm_tx_16(struct sf_pwmdac_dev *dev,
struct snd_pcm_runtime *runtime, unsigned int tx_ptr,
bool *period_elapsed)
{
const u16 (*p)[2] = (void *)runtime->dma_area;
unsigned int period_pos = tx_ptr % runtime->period_size;
int i;
u32 basedat = 0;
for (i = 0; i < dev->fifo_th; i++) {
basedat = (p[tx_ptr][0])|(p[tx_ptr][1] << 16);
iowrite32(basedat,dev->pwmdac_base + PWMDAC_WDATA);
period_pos++;
if (++tx_ptr >= runtime->buffer_size)
tx_ptr = 0;
}
*period_elapsed = period_pos >= runtime->period_size;
return tx_ptr;
}
static const struct snd_pcm_hardware sf_pcm_hardware = {
.info = SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_BLOCK_TRANSFER,
.rates = SNDRV_PCM_RATE_16000,
.rate_min = 16000,
.rate_max = 16000,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.channels_min = 2,
.channels_max = 2,
.buffer_bytes_max = BUFFER_BYTES_MAX,
.period_bytes_min = PERIOD_BYTES_MIN,
.period_bytes_max = BUFFER_BYTES_MAX / PERIODS_MIN,
.periods_min = PERIODS_MIN,
.periods_max = BUFFER_BYTES_MAX / PERIOD_BYTES_MIN,
.fifo_size = 2,
};
static void sf_pcm_transfer(struct sf_pwmdac_dev *dev, bool push)
{
struct snd_pcm_substream *substream = NULL;
bool period_elapsed = false;
bool active;
rcu_read_lock();
if (push)
substream = rcu_dereference(dev->tx_substream);
active = substream && snd_pcm_running(substream);
if (active) {
unsigned int ptr;
unsigned int new_ptr;
if (push) {
ptr = READ_ONCE(dev->tx_ptr);
new_ptr = dev->tx_fn(dev, substream->runtime, ptr,
&period_elapsed);
cmpxchg(&dev->tx_ptr, ptr, new_ptr);
}
if (period_elapsed)
snd_pcm_period_elapsed(substream);
}
rcu_read_unlock();
}
void sf_pwmdac_pcm_push_tx(struct sf_pwmdac_dev *dev)
{
sf_pcm_transfer(dev, true);
}
static int sf_pcm_open(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
struct sf_pwmdac_dev *dev = snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
snd_soc_set_runtime_hwparams(substream, &sf_pcm_hardware);
snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
runtime->private_data = dev;
return 0;
}
static int sf_pcm_close(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
synchronize_rcu();
return 0;
}
static int sf_pcm_hw_params(struct snd_soc_component *component,
struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct sf_pwmdac_dev *dev = runtime->private_data;
switch (params_channels(hw_params)) {
case 2:
break;
default:
dev_err(dev->dev, "invalid channels number\n");
return -EINVAL;
}
switch (params_format(hw_params)) {
case SNDRV_PCM_FORMAT_U8:
case SNDRV_PCM_FORMAT_S8:
dev->tx_fn = sf_pwmdac_pcm_tx_8;
break;
case SNDRV_PCM_FORMAT_S16_LE:
dev->tx_fn = sf_pwmdac_pcm_tx_16;
break;
default:
dev_err(dev->dev, "invalid format\n");
return -EINVAL;
}
return 0;
}
static int sf_pcm_trigger(struct snd_soc_component *component,
struct snd_pcm_substream *substream, int cmd)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct sf_pwmdac_dev *dev = runtime->private_data;
int ret = 0;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
WRITE_ONCE(dev->tx_ptr, 0);
rcu_assign_pointer(dev->tx_substream, substream);
}
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
rcu_assign_pointer(dev->tx_substream, NULL);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static snd_pcm_uframes_t sf_pcm_pointer(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct sf_pwmdac_dev *dev = runtime->private_data;
snd_pcm_uframes_t pos = 0;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
pos = READ_ONCE(dev->tx_ptr);
return pos < runtime->buffer_size ? pos : 0;
}
static int sf_pcm_new(struct snd_soc_component *component,
struct snd_soc_pcm_runtime *rtd)
{
size_t size = sf_pcm_hardware.buffer_bytes_max;
snd_pcm_set_managed_buffer_all(rtd->pcm,
SNDRV_DMA_TYPE_CONTINUOUS,
NULL, size, size);
return 0;
}
static const struct snd_soc_component_driver dw_pcm_component = {
.open = sf_pcm_open,
.close = sf_pcm_close,
.hw_params = sf_pcm_hw_params,
.trigger = sf_pcm_trigger,
.pointer = sf_pcm_pointer,
.pcm_construct = sf_pcm_new,
};
int sf_pwmdac_pcm_register(struct platform_device *pdev)
{
return devm_snd_soc_register_component(&pdev->dev, &dw_pcm_component,
NULL, 0);
}
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