/* * 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; void *data; }; static inline struct dmaengine_pcm_runtime_data *substream_to_prtd( const struct snd_pcm_substream *substream) { return substream->runtime->private_data; } /** * snd_dmaengine_pcm_set_data - Set dmaengine substream private data * @substream: PCM substream * @data: Data to set */ void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data) { struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); prtd->data = data; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data); /** * snd_dmaengine_pcm_get_data - Get dmaeinge substream private data * @substream: PCM substream * * Returns the data previously set with snd_dmaengine_pcm_set_data */ void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream) { struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); return prtd->data; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_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; } return 0; } EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); 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); static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd, 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); prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data); if (!prtd->dma_chan) return -ENXIO; return 0; } /** * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream * @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. If you need * to keep additional data attached to a substream use * snd_dmaengine_pcm_{set,get}_data. */ int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, dma_filter_fn filter_fn, void *filter_data) { struct dmaengine_pcm_runtime_data *prtd; int ret; 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; ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data); if (ret < 0) { kfree(prtd); return ret; } substream->runtime->private_data = prtd; return 0; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); /** * 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); dma_release_channel(prtd->dma_chan); kfree(prtd); return 0; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);