diff options
Diffstat (limited to 'sound/soc/soc-generic-dmaengine-pcm.c')
| -rw-r--r-- | sound/soc/soc-generic-dmaengine-pcm.c | 241 |
1 files changed, 241 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 000000000000..acfc92698995 --- /dev/null +++ b/sound/soc/soc-generic-dmaengine-pcm.c @@ -0,0 +1,241 @@ +/* + * Copyright (C) 2013, Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ +#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 <linux/of_dma.h> + +#include <sound/dmaengine_pcm.h> + +struct dmaengine_pcm { + struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1]; + const struct snd_dmaengine_pcm_config *config; + struct snd_soc_platform platform; +}; + +static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p) +{ + return container_of(p, struct dmaengine_pcm, platform); +} + +/** + * 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 dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); + struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); + struct dma_slave_config slave_config; + int ret; + + if (pcm->config->prepare_slave_config) { + ret = pcm->config->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_open(struct snd_pcm_substream *substream) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); + struct dma_chan *chan = pcm->chan[substream->stream]; + int ret; + + ret = snd_soc_set_runtime_hwparams(substream, + pcm->config->pcm_hardware); + if (ret) + return ret; + + return snd_dmaengine_pcm_open(substream, chan); +} + +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; +} + +static void dmaengine_pcm_free(struct snd_pcm *pcm) +{ + snd_pcm_lib_preallocate_free_for_all(pcm); +} + +static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) +{ + struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); + const struct snd_dmaengine_pcm_config *config = pcm->config; + struct snd_pcm_substream *substream; + unsigned int i; + int ret; + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { + substream = rtd->pcm->streams[i].substream; + if (!substream) + continue; + + if (!pcm->chan[i]) { + dev_err(rtd->platform->dev, + "Missing dma channel for stream: %d\n", i); + ret = -EINVAL; + goto err_free; + } + + ret = snd_pcm_lib_preallocate_pages(substream, + SNDRV_DMA_TYPE_DEV, + dmaengine_dma_dev(pcm, substream), + config->prealloc_buffer_size, + config->pcm_hardware->buffer_bytes_max); + if (ret) + goto err_free; + } + + return 0; + +err_free: + dmaengine_pcm_free(rtd->pcm); + return ret; +} + +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 = snd_dmaengine_pcm_pointer, +}; + +static const struct snd_soc_platform_driver dmaengine_pcm_platform = { + .ops = &dmaengine_pcm_ops, + .pcm_new = dmaengine_pcm_new, + .pcm_free = dmaengine_pcm_free, +}; + +static const char * const dmaengine_pcm_dma_channel_names[] = { + [SNDRV_PCM_STREAM_PLAYBACK] = "tx", + [SNDRV_PCM_STREAM_CAPTURE] = "rx", +}; + +/** + * 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; + unsigned int i; + + if (!dev->of_node) + return -EINVAL; + + pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); + if (!pcm) + return -ENOMEM; + + pcm->config = config; + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { + pcm->chan[i] = of_dma_request_slave_channel(dev->of_node, + dmaengine_pcm_dma_channel_names[i]); + } + + return snd_soc_add_platform(dev, &pcm->platform, + &dmaengine_pcm_platform); +} +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_platform *platform; + struct dmaengine_pcm *pcm; + unsigned int i; + + platform = snd_soc_lookup_platform(dev); + if (!platform) + return; + + pcm = soc_platform_to_pcm(platform); + + for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { + if (pcm->chan[i]) + dma_release_channel(pcm->chan[i]); + } + + snd_soc_remove_platform(platform); + kfree(pcm); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); + +MODULE_LICENSE("GPL"); |