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Diffstat (limited to 'sound/core/pcm_dmaengine.c')
| -rw-r--r-- | sound/core/pcm_dmaengine.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c new file mode 100644 index 000000000000..aa924d9b7986 --- /dev/null +++ b/sound/core/pcm_dmaengine.c @@ -0,0 +1,367 @@ +/* + * Copyright (C) 2012, Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Based on: + * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de> + * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc. + * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> + * Copyright (C) 2006 Applied Data Systems + * + * 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 <sound/dmaengine_pcm.h> + +struct dmaengine_pcm_runtime_data { + struct dma_chan *dma_chan; + dma_cookie_t cookie; + + unsigned int pos; +}; + +static inline struct dmaengine_pcm_runtime_data *substream_to_prtd( + const struct snd_pcm_substream *substream) +{ + return substream->runtime->private_data; +} + +struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + + return prtd->dma_chan; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan); + +/** + * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config + * @substream: PCM substream + * @params: hw_params + * @slave_config: DMA slave config + * + * This function can be used to initialize a dma_slave_config from a substream + * and hw_params in a dmaengine based PCM driver implementation. + */ +int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream, + const struct snd_pcm_hw_params *params, + struct dma_slave_config *slave_config) +{ + enum dma_slave_buswidth buswidth; + + switch (params_format(params)) { + case SNDRV_PCM_FORMAT_S8: + buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; + break; + case SNDRV_PCM_FORMAT_S16_LE: + buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; + break; + case SNDRV_PCM_FORMAT_S18_3LE: + case SNDRV_PCM_FORMAT_S20_3LE: + case SNDRV_PCM_FORMAT_S24_LE: + case SNDRV_PCM_FORMAT_S32_LE: + buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; + break; + default: + return -EINVAL; + } + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + slave_config->direction = DMA_MEM_TO_DEV; + slave_config->dst_addr_width = buswidth; + } else { + slave_config->direction = DMA_DEV_TO_MEM; + slave_config->src_addr_width = buswidth; + } + + slave_config->device_fc = false; + + return 0; +} +EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); + +/** + * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config + * using DAI DMA data. + * @substream: PCM substream + * @dma_data: DAI DMA data + * @slave_config: DMA slave configuration + * + * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and + * slave_id fields of the DMA slave config from the same fields of the DAI DMA + * data struct. The src and dst fields will be initialized depending on the + * direction of the substream. If the substream is a playback stream the dst + * fields will be initialized, if it is a capture stream the src fields will be + * initialized. The {dst,src}_addr_width field will only be initialized if the + * addr_width field of the DAI DMA data struct is not equal to + * DMA_SLAVE_BUSWIDTH_UNDEFINED. + */ +void snd_dmaengine_pcm_set_config_from_dai_data( + const struct snd_pcm_substream *substream, + const struct snd_dmaengine_dai_dma_data *dma_data, + struct dma_slave_config *slave_config) +{ + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + slave_config->dst_addr = dma_data->addr; + slave_config->dst_maxburst = dma_data->maxburst; + if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) + slave_config->dst_addr_width = dma_data->addr_width; + } else { + slave_config->src_addr = dma_data->addr; + slave_config->src_maxburst = dma_data->maxburst; + if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) + slave_config->src_addr_width = dma_data->addr_width; + } + + slave_config->slave_id = dma_data->slave_id; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); + +static void dmaengine_pcm_dma_complete(void *arg) +{ + struct snd_pcm_substream *substream = arg; + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + + prtd->pos += snd_pcm_lib_period_bytes(substream); + if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) + prtd->pos = 0; + + snd_pcm_period_elapsed(substream); +} + +static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + struct dma_chan *chan = prtd->dma_chan; + struct dma_async_tx_descriptor *desc; + enum dma_transfer_direction direction; + unsigned long flags = DMA_CTRL_ACK; + + direction = snd_pcm_substream_to_dma_direction(substream); + + if (!substream->runtime->no_period_wakeup) + flags |= DMA_PREP_INTERRUPT; + + prtd->pos = 0; + desc = dmaengine_prep_dma_cyclic(chan, + substream->runtime->dma_addr, + snd_pcm_lib_buffer_bytes(substream), + snd_pcm_lib_period_bytes(substream), direction, flags); + + if (!desc) + return -ENOMEM; + + desc->callback = dmaengine_pcm_dma_complete; + desc->callback_param = substream; + prtd->cookie = dmaengine_submit(desc); + + return 0; +} + +/** + * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation + * @substream: PCM substream + * @cmd: Trigger command + * + * Returns 0 on success, a negative error code otherwise. + * + * This function can be used as the PCM trigger callback for dmaengine based PCM + * driver implementations. + */ +int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + int ret; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + ret = dmaengine_pcm_prepare_and_submit(substream); + if (ret) + return ret; + dma_async_issue_pending(prtd->dma_chan); + break; + case SNDRV_PCM_TRIGGER_RESUME: + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + dmaengine_resume(prtd->dma_chan); + break; + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + dmaengine_pause(prtd->dma_chan); + break; + case SNDRV_PCM_TRIGGER_STOP: + dmaengine_terminate_all(prtd->dma_chan); + break; + default: + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); + +/** + * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation + * @substream: PCM substream + * + * This function is deprecated and should not be used by new drivers, as its + * results may be unreliable. + */ +snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + return bytes_to_frames(substream->runtime, prtd->pos); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); + +/** + * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation + * @substream: PCM substream + * + * This function can be used as the PCM pointer callback for dmaengine based PCM + * driver implementations. + */ +snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + struct dma_tx_state state; + enum dma_status status; + unsigned int buf_size; + unsigned int pos = 0; + + status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); + if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { + buf_size = snd_pcm_lib_buffer_bytes(substream); + if (state.residue > 0 && state.residue <= buf_size) + pos = buf_size - state.residue; + } + + return bytes_to_frames(substream->runtime, pos); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); + +/** + * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM + * @filter_fn: Filter function used to request the DMA channel + * @filter_data: Data passed to the DMA filter function + * + * Returns NULL or the requested DMA channel. + * + * This function request a DMA channel for usage with dmaengine PCM. + */ +struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, + void *filter_data) +{ + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + dma_cap_set(DMA_CYCLIC, mask); + + return dma_request_channel(mask, filter_fn, filter_data); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); + +/** + * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream + * @substream: PCM substream + * @chan: DMA channel to use for data transfers + * + * Returns 0 on success, a negative error code otherwise. + * + * The function should usually be called from the pcm open callback. Note that + * this function will use private_data field of the substream's runtime. So it + * is not availabe to your pcm driver implementation. + */ +int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, + struct dma_chan *chan) +{ + struct dmaengine_pcm_runtime_data *prtd; + int ret; + + if (!chan) + return -ENXIO; + + ret = snd_pcm_hw_constraint_integer(substream->runtime, + SNDRV_PCM_HW_PARAM_PERIODS); + if (ret < 0) + return ret; + + prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); + if (!prtd) + return -ENOMEM; + + prtd->dma_chan = chan; + + substream->runtime->private_data = prtd; + + return 0; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); + +/** + * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel + * @substream: PCM substream + * @filter_fn: Filter function used to request the DMA channel + * @filter_data: Data passed to the DMA filter function + * + * Returns 0 on success, a negative error code otherwise. + * + * This function will request a DMA channel using the passed filter function and + * data. The function should usually be called from the pcm open callback. Note + * that this function will use private_data field of the substream's runtime. So + * it is not availabe to your pcm driver implementation. + */ +int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, + dma_filter_fn filter_fn, void *filter_data) +{ + return snd_dmaengine_pcm_open(substream, + snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); + +/** + * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream + * @substream: PCM substream + */ +int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + + kfree(prtd); + + return 0; +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); + +/** + * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel + * @substream: PCM substream + * + * Releases the DMA channel associated with the PCM substream. + */ +int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) +{ + struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); + + dma_release_channel(prtd->dma_chan); + + return snd_dmaengine_pcm_close(substream); +} +EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); + +MODULE_LICENSE("GPL"); |