diff options
Diffstat (limited to 'sound/soc/starfive/pwmdac-pcm.c')
| -rw-r--r-- | sound/soc/starfive/pwmdac-pcm.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/sound/soc/starfive/pwmdac-pcm.c b/sound/soc/starfive/pwmdac-pcm.c new file mode 100644 index 000000000000..d8d5dd2f3556 --- /dev/null +++ b/sound/soc/starfive/pwmdac-pcm.c @@ -0,0 +1,233 @@ +// 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); +} |