diff options
Diffstat (limited to '')
| -rw-r--r-- | sound/soc/soc-generic-dmaengine-pcm.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c new file mode 100644 index 000000000..232df04ca --- /dev/null +++ b/sound/soc/soc-generic-dmaengine-pcm.c @@ -0,0 +1,548 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright (C) 2013, Analog Devices Inc. +// Author: Lars-Peter Clausen <lars@metafoo.de> + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/dmaengine.h> +#include <linux/slab.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/soc.h> +#include <linux/dma-mapping.h> +#include <linux/of.h> + +#include <sound/dmaengine_pcm.h> + +/* + * The platforms dmaengine driver does not support reporting the amount of + * bytes that are still left to transfer. + */ +#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) + +struct dmaengine_pcm { + struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1]; + const struct snd_dmaengine_pcm_config *config; + struct snd_soc_component component; + unsigned int flags; +}; + +static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p) +{ + return container_of(p, struct dmaengine_pcm, component); +} + +static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, + struct snd_pcm_substream *substream) +{ + if (!pcm->chan[substream->stream]) + return NULL; + + return pcm->chan[substream->stream]->device->dev; +} + +/** + * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback + * @substream: PCM substream + * @params: hw_params + * @slave_config: DMA slave config to prepare + * + * This function can be used as a generic prepare_slave_config callback for + * platforms which make use of the snd_dmaengine_dai_dma_data struct for their + * DAI DMA data. Internally the function will first call + * snd_hwparams_to_dma_slave_config to fill in the slave config based on the + * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the + * remaining fields based on the DAI DMA data. + */ +int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_dmaengine_dai_dma_data *dma_data; + int ret; + + dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); + + ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); + if (ret) + return ret; + + snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, + slave_config); + + return 0; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); + +static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); + int (*prepare_slave_config)(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, + struct dma_slave_config *slave_config); + struct dma_slave_config slave_config; + int ret; + + memset(&slave_config, 0, sizeof(slave_config)); + + if (!pcm->config) + prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config; + else + prepare_slave_config = pcm->config->prepare_slave_config; + + if (prepare_slave_config) { + ret = prepare_slave_config(substream, params, &slave_config); + if (ret) + return ret; + + ret = dmaengine_slave_config(chan, &slave_config); + if (ret) + return ret; + } + + return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); +} + +static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + struct device *dma_dev = dmaengine_dma_dev(pcm, substream); + struct dma_chan *chan = pcm->chan[substream->stream]; + struct snd_dmaengine_dai_dma_data *dma_data; + struct dma_slave_caps dma_caps; + struct snd_pcm_hardware hw; + u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + snd_pcm_format_t i; + int ret; + + if (pcm->config && pcm->config->pcm_hardware) + return snd_soc_set_runtime_hwparams(substream, + pcm->config->pcm_hardware); + + dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); + + memset(&hw, 0, sizeof(hw)); + hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_INTERLEAVED; + hw.periods_min = 2; + hw.periods_max = UINT_MAX; + hw.period_bytes_min = 256; + hw.period_bytes_max = dma_get_max_seg_size(dma_dev); + hw.buffer_bytes_max = SIZE_MAX; + hw.fifo_size = dma_data->fifo_size; + + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) + hw.info |= SNDRV_PCM_INFO_BATCH; + + ret = dma_get_slave_caps(chan, &dma_caps); + if (ret == 0) { + if (dma_caps.cmd_pause && dma_caps.cmd_resume) + hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; + if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) + hw.info |= SNDRV_PCM_INFO_BATCH; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + addr_widths = dma_caps.dst_addr_widths; + else + addr_widths = dma_caps.src_addr_widths; + } + + /* + * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep + * hw.formats set to 0, meaning no restrictions are in place. + * In this case it's the responsibility of the DAI driver to + * provide the supported format information. + */ + if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) + /* + * Prepare formats mask for valid/allowed sample types. If the + * dma does not have support for the given physical word size, + * it needs to be masked out so user space can not use the + * format which produces corrupted audio. + * In case the dma driver does not implement the slave_caps the + * default assumption is that it supports 1, 2 and 4 bytes + * widths. + */ + for (i = SNDRV_PCM_FORMAT_FIRST; i <= SNDRV_PCM_FORMAT_LAST; i++) { + int bits = snd_pcm_format_physical_width(i); + + /* + * Enable only samples with DMA supported physical + * widths + */ + switch (bits) { + case 8: + case 16: + case 24: + case 32: + case 64: + if (addr_widths & (1 << (bits / 8))) + hw.formats |= pcm_format_to_bits(i); + break; + default: + /* Unsupported types */ + break; + } + } + + return snd_soc_set_runtime_hwparams(substream, &hw); +} + +static int dmaengine_pcm_open(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + struct dma_chan *chan = pcm->chan[substream->stream]; + int ret; + + ret = dmaengine_pcm_set_runtime_hwparams(substream); + if (ret) + return ret; + + return snd_dmaengine_pcm_open(substream, chan); +} + +static struct dma_chan *dmaengine_pcm_compat_request_channel( + struct snd_soc_pcm_runtime *rtd, + struct snd_pcm_substream *substream) +{ + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + struct snd_dmaengine_dai_dma_data *dma_data; + dma_filter_fn fn = NULL; + + dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); + + if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) + return pcm->chan[0]; + + if (pcm->config && pcm->config->compat_request_channel) + return pcm->config->compat_request_channel(rtd, substream); + + if (pcm->config) + fn = pcm->config->compat_filter_fn; + + return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data); +} + +static bool dmaengine_pcm_can_report_residue(struct device *dev, + struct dma_chan *chan) +{ + struct dma_slave_caps dma_caps; + int ret; + + ret = dma_get_slave_caps(chan, &dma_caps); + if (ret != 0) { + dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", + ret); + return false; + } + + if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) + return false; + + return true; +} + +static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) +{ + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + const struct snd_dmaengine_pcm_config *config = pcm->config; + struct device *dev = component->dev; + struct snd_dmaengine_dai_dma_data *dma_data; + struct snd_pcm_substream *substream; + size_t prealloc_buffer_size; + size_t max_buffer_size; + unsigned int i; + int ret; + + if (config && config->prealloc_buffer_size) { + prealloc_buffer_size = config->prealloc_buffer_size; + max_buffer_size = config->pcm_hardware->buffer_bytes_max; + } else { + prealloc_buffer_size = 512 * 1024; + max_buffer_size = SIZE_MAX; + } + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { + substream = rtd->pcm->streams[i].substream; + if (!substream) + continue; + + dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); + + if (!pcm->chan[i] && + (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) + pcm->chan[i] = dma_request_slave_channel(dev, + dma_data->chan_name); + + if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { + pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, + substream); + } + + if (!pcm->chan[i]) { + dev_err(component->dev, + "Missing dma channel for stream: %d\n", i); + return -EINVAL; + } + + ret = snd_pcm_lib_preallocate_pages(substream, + SNDRV_DMA_TYPE_DEV_IRAM, + dmaengine_dma_dev(pcm, substream), + prealloc_buffer_size, + max_buffer_size); + if (ret) + return ret; + + if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) + pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; + + if (rtd->pcm->streams[i].pcm->name[0] == '\0') { + strncpy(rtd->pcm->streams[i].pcm->name, + rtd->pcm->streams[i].pcm->id, + sizeof(rtd->pcm->streams[i].pcm->name)); + } + } + + return 0; +} + +static snd_pcm_uframes_t dmaengine_pcm_pointer( + struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) + return snd_dmaengine_pcm_pointer_no_residue(substream); + else + return snd_dmaengine_pcm_pointer(substream); +} + +static int dmaengine_copy_user(struct snd_pcm_substream *substream, + int channel, unsigned long hwoff, + void __user *buf, unsigned long bytes) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_component *component = + snd_soc_rtdcom_lookup(rtd, SND_DMAENGINE_PCM_DRV_NAME); + struct snd_pcm_runtime *runtime = substream->runtime; + struct dmaengine_pcm *pcm = soc_component_to_pcm(component); + int (*process)(struct snd_pcm_substream *substream, + int channel, unsigned long hwoff, + void *buf, unsigned long bytes) = pcm->config->process; + bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; + void *dma_ptr = runtime->dma_area + hwoff + + channel * (runtime->dma_bytes / runtime->channels); + int ret; + + if (is_playback) + if (copy_from_user(dma_ptr, buf, bytes)) + return -EFAULT; + + if (process) { + ret = process(substream, channel, hwoff, (__force void *)buf, bytes); + if (ret < 0) + return ret; + } + + if (!is_playback) + if (copy_to_user(buf, dma_ptr, bytes)) + return -EFAULT; + + return 0; +} + +static const struct snd_pcm_ops dmaengine_pcm_ops = { + .open = dmaengine_pcm_open, + .close = snd_dmaengine_pcm_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = dmaengine_pcm_hw_params, + .hw_free = snd_pcm_lib_free_pages, + .trigger = snd_dmaengine_pcm_trigger, + .pointer = dmaengine_pcm_pointer, +}; + +static const struct snd_pcm_ops dmaengine_pcm_process_ops = { + .open = dmaengine_pcm_open, + .close = snd_dmaengine_pcm_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = dmaengine_pcm_hw_params, + .hw_free = snd_pcm_lib_free_pages, + .trigger = snd_dmaengine_pcm_trigger, + .pointer = dmaengine_pcm_pointer, + .copy_user = dmaengine_copy_user, +}; + +static const struct snd_soc_component_driver dmaengine_pcm_component = { + .name = SND_DMAENGINE_PCM_DRV_NAME, + .probe_order = SND_SOC_COMP_ORDER_LATE, + .ops = &dmaengine_pcm_ops, + .pcm_new = dmaengine_pcm_new, +}; + +static const struct snd_soc_component_driver dmaengine_pcm_component_process = { + .name = SND_DMAENGINE_PCM_DRV_NAME, + .probe_order = SND_SOC_COMP_ORDER_LATE, + .ops = &dmaengine_pcm_process_ops, + .pcm_new = dmaengine_pcm_new, +}; + +static const char * const dmaengine_pcm_dma_channel_names[] = { + [SNDRV_PCM_STREAM_PLAYBACK] = "tx", + [SNDRV_PCM_STREAM_CAPTURE] = "rx", +}; + +static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, + struct device *dev, const struct snd_dmaengine_pcm_config *config) +{ + unsigned int i; + const char *name; + struct dma_chan *chan; + + if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT | + SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) || + !dev->of_node) + return 0; + + if (config && config->dma_dev) { + /* + * If this warning is seen, it probably means that your Linux + * device structure does not match your HW device structure. + * It would be best to refactor the Linux device structure to + * correctly match the HW structure. + */ + dev_warn(dev, "DMA channels sourced from device %s", + dev_name(config->dma_dev)); + dev = config->dma_dev; + } + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; + i++) { + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) + name = "rx-tx"; + else + name = dmaengine_pcm_dma_channel_names[i]; + if (config && config->chan_names[i]) + name = config->chan_names[i]; + chan = dma_request_slave_channel_reason(dev, name); + if (IS_ERR(chan)) { + if (PTR_ERR(chan) == -EPROBE_DEFER) + return -EPROBE_DEFER; + pcm->chan[i] = NULL; + } else { + pcm->chan[i] = chan; + } + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) + break; + } + + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) + pcm->chan[1] = pcm->chan[0]; + + return 0; +} + +static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) +{ + unsigned int i; + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; + i++) { + if (!pcm->chan[i]) + continue; + dma_release_channel(pcm->chan[i]); + if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) + break; + } +} + +/** + * snd_dmaengine_pcm_register - Register a dmaengine based PCM device + * @dev: The parent device for the PCM device + * @config: Platform specific PCM configuration + * @flags: Platform specific quirks + */ +int snd_dmaengine_pcm_register(struct device *dev, + const struct snd_dmaengine_pcm_config *config, unsigned int flags) +{ + struct dmaengine_pcm *pcm; + int ret; + + pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); + if (!pcm) + return -ENOMEM; + +#ifdef CONFIG_DEBUG_FS + pcm->component.debugfs_prefix = "dma"; +#endif + pcm->config = config; + pcm->flags = flags; + + ret = dmaengine_pcm_request_chan_of(pcm, dev, config); + if (ret) + goto err_free_dma; + + if (config && config->process) + ret = snd_soc_add_component(dev, &pcm->component, + &dmaengine_pcm_component_process, + NULL, 0); + else + ret = snd_soc_add_component(dev, &pcm->component, + &dmaengine_pcm_component, NULL, 0); + if (ret) + goto err_free_dma; + + return 0; + +err_free_dma: + dmaengine_pcm_release_chan(pcm); + kfree(pcm); + return ret; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); + +/** + * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device + * @dev: Parent device the PCM was register with + * + * Removes a dmaengine based PCM device previously registered with + * snd_dmaengine_pcm_register. + */ +void snd_dmaengine_pcm_unregister(struct device *dev) +{ + struct snd_soc_component *component; + struct dmaengine_pcm *pcm; + + component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); + if (!component) + return; + + pcm = soc_component_to_pcm(component); + + snd_soc_unregister_component(dev); + dmaengine_pcm_release_chan(pcm); + kfree(pcm); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); + +MODULE_LICENSE("GPL"); |