sound/core/pcm_dmaengine.c

   1 /*
   2  *  Copyright (C) 2012, Analog Devices Inc.
   3  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  *  Based on:
   6  *      imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   7  *      mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
   8  *      ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
   9  *                    Copyright (C) 2006 Applied Data Systems
  10  *
  11  *  This program is free software; you can redistribute it and/or modify it
  12  *  under  the terms of the GNU General  Public License as published by the
  13  *  Free Software Foundation;  either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/dmaengine.h>
  24 #include <linux/slab.h>
  25 #include <sound/pcm.h>
  26 #include <sound/pcm_params.h>
  27 #include <sound/soc.h>
  28
  29 #include <sound/dmaengine_pcm.h>
  30
  31 struct dmaengine_pcm_runtime_data {
  32         struct dma_chan *dma_chan;
  33         dma_cookie_t cookie;
  34
  35         unsigned int pos;
  36 };
  37
  38 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  39         const struct snd_pcm_substream *substream)
  40 {
  41         return substream->runtime->private_data;
  42 }
  43
  44 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  45 {
  46         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  47
  48         return prtd->dma_chan;
  49 }
  50 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  51
  52 /**
  53  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  54  * @substream: PCM substream
  55  * @params: hw_params
  56  * @slave_config: DMA slave config
  57  *
  58  * This function can be used to initialize a dma_slave_config from a substream
  59  * and hw_params in a dmaengine based PCM driver implementation.
  60  */
  61 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  62         const struct snd_pcm_hw_params *params,
  63         struct dma_slave_config *slave_config)
  64 {
  65         enum dma_slave_buswidth buswidth;
  66         int bits;
  67
  68         bits = snd_pcm_format_physical_width(params_format(params));
  69         if (bits < 8 || bits > 64)
  70                 return -EINVAL;
  71         else if (bits == 8)
  72                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  73         else if (bits == 16)
  74                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  75         else if (bits <= 32)
  76                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  77         else
  78                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  79
  80         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  81                 slave_config->direction = DMA_MEM_TO_DEV;
  82                 slave_config->dst_addr_width = buswidth;
  83         } else {
  84                 slave_config->direction = DMA_DEV_TO_MEM;
  85                 slave_config->src_addr_width = buswidth;
  86         }
  87
  88         slave_config->device_fc = false;
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  93
  94 /**
  95  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  96  *  using DAI DMA data.
  97  * @substream: PCM substream
  98  * @dma_data: DAI DMA data
  99  * @slave_config: DMA slave configuration
 100  *
 101  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
 102  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
 103  * data struct. The src and dst fields will be initialized depending on the
 104  * direction of the substream. If the substream is a playback stream the dst
 105  * fields will be initialized, if it is a capture stream the src fields will be
 106  * initialized. The {dst,src}_addr_width field will only be initialized if the
 107  * addr_width field of the DAI DMA data struct is not equal to
 108  * DMA_SLAVE_BUSWIDTH_UNDEFINED.
 109  */
 110 void snd_dmaengine_pcm_set_config_from_dai_data(
 111         const struct snd_pcm_substream *substream,
 112         const struct snd_dmaengine_dai_dma_data *dma_data,
 113         struct dma_slave_config *slave_config)
 114 {
 115         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 116                 slave_config->dst_addr = dma_data->addr;
 117                 slave_config->dst_maxburst = dma_data->maxburst;
 118                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 119                         slave_config->dst_addr_width = dma_data->addr_width;
 120         } else {
 121                 slave_config->src_addr = dma_data->addr;
 122                 slave_config->src_maxburst = dma_data->maxburst;
 123                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 124                         slave_config->src_addr_width = dma_data->addr_width;
 125         }
 126
 127         slave_config->slave_id = dma_data->slave_id;
 128 }
 129 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 130
 131 static void dmaengine_pcm_dma_complete(void *arg)
 132 {
 133         struct snd_pcm_substream *substream = arg;
 134         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 135
 136         prtd->pos += snd_pcm_lib_period_bytes(substream);
 137         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 138                 prtd->pos = 0;
 139
 140         snd_pcm_period_elapsed(substream);
 141 }
 142
 143 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 144 {
 145         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 146         struct dma_chan *chan = prtd->dma_chan;
 147         struct dma_async_tx_descriptor *desc;
 148         enum dma_transfer_direction direction;
 149         unsigned long flags = DMA_CTRL_ACK;
 150
 151         direction = snd_pcm_substream_to_dma_direction(substream);
 152
 153         if (!substream->runtime->no_period_wakeup)
 154                 flags |= DMA_PREP_INTERRUPT;
 155
 156         prtd->pos = 0;
 157         desc = dmaengine_prep_dma_cyclic(chan,
 158                 substream->runtime->dma_addr,
 159                 snd_pcm_lib_buffer_bytes(substream),
 160                 snd_pcm_lib_period_bytes(substream), direction, flags);
 161
 162         if (!desc)
 163                 return -ENOMEM;
 164
 165         desc->callback = dmaengine_pcm_dma_complete;
 166         desc->callback_param = substream;
 167         prtd->cookie = dmaengine_submit(desc);
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 174  * @substream: PCM substream
 175  * @cmd: Trigger command
 176  *
 177  * Returns 0 on success, a negative error code otherwise.
 178  *
 179  * This function can be used as the PCM trigger callback for dmaengine based PCM
 180  * driver implementations.
 181  */
 182 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 183 {
 184         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 185         int ret;
 186
 187         switch (cmd) {
 188         case SNDRV_PCM_TRIGGER_START:
 189                 ret = dmaengine_pcm_prepare_and_submit(substream);
 190                 if (ret)
 191                         return ret;
 192                 dma_async_issue_pending(prtd->dma_chan);
 193                 break;
 194         case SNDRV_PCM_TRIGGER_RESUME:
 195         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 196                 dmaengine_resume(prtd->dma_chan);
 197                 break;
 198         case SNDRV_PCM_TRIGGER_SUSPEND:
 199         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 200                 dmaengine_pause(prtd->dma_chan);
 201                 break;
 202         case SNDRV_PCM_TRIGGER_STOP:
 203                 dmaengine_terminate_all(prtd->dma_chan);
 204                 break;
 205         default:
 206                 return -EINVAL;
 207         }
 208
 209         return 0;
 210 }
 211 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 212
 213 /**
 214  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 215  * @substream: PCM substream
 216  *
 217  * This function is deprecated and should not be used by new drivers, as its
 218  * results may be unreliable.
 219  */
 220 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 221 {
 222         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 223         return bytes_to_frames(substream->runtime, prtd->pos);
 224 }
 225 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 226
 227 /**
 228  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 229  * @substream: PCM substream
 230  *
 231  * This function can be used as the PCM pointer callback for dmaengine based PCM
 232  * driver implementations.
 233  */
 234 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 235 {
 236         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 237         struct dma_tx_state state;
 238         enum dma_status status;
 239         unsigned int buf_size;
 240         unsigned int pos = 0;
 241
 242         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 243         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 244                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 245                 if (state.residue > 0 && state.residue <= buf_size)
 246                         pos = buf_size - state.residue;
 247         }
 248
 249         return bytes_to_frames(substream->runtime, pos);
 250 }
 251 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 252
 253 /**
 254  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 255  * @filter_fn: Filter function used to request the DMA channel
 256  * @filter_data: Data passed to the DMA filter function
 257  *
 258  * Returns NULL or the requested DMA channel.
 259  *
 260  * This function request a DMA channel for usage with dmaengine PCM.
 261  */
 262 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 263         void *filter_data)
 264 {
 265         dma_cap_mask_t mask;
 266
 267         dma_cap_zero(mask);
 268         dma_cap_set(DMA_SLAVE, mask);
 269         dma_cap_set(DMA_CYCLIC, mask);
 270
 271         return dma_request_channel(mask, filter_fn, filter_data);
 272 }
 273 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 274
 275 /**
 276  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 277  * @substream: PCM substream
 278  * @chan: DMA channel to use for data transfers
 279  *
 280  * Returns 0 on success, a negative error code otherwise.
 281  *
 282  * The function should usually be called from the pcm open callback. Note that
 283  * this function will use private_data field of the substream's runtime. So it
 284  * is not availabe to your pcm driver implementation.
 285  */
 286 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 287         struct dma_chan *chan)
 288 {
 289         struct dmaengine_pcm_runtime_data *prtd;
 290         int ret;
 291
 292         if (!chan)
 293                 return -ENXIO;
 294
 295         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 296                                             SNDRV_PCM_HW_PARAM_PERIODS);
 297         if (ret < 0)
 298                 return ret;
 299
 300         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 301         if (!prtd)
 302                 return -ENOMEM;
 303
 304         prtd->dma_chan = chan;
 305
 306         substream->runtime->private_data = prtd;
 307
 308         return 0;
 309 }
 310 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 311
 312 /**
 313  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 314  * @substream: PCM substream
 315  * @filter_fn: Filter function used to request the DMA channel
 316  * @filter_data: Data passed to the DMA filter function
 317  *
 318  * Returns 0 on success, a negative error code otherwise.
 319  *
 320  * This function will request a DMA channel using the passed filter function and
 321  * data. The function should usually be called from the pcm open callback. Note
 322  * that this function will use private_data field of the substream's runtime. So
 323  * it is not availabe to your pcm driver implementation.
 324  */
 325 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 326         dma_filter_fn filter_fn, void *filter_data)
 327 {
 328         return snd_dmaengine_pcm_open(substream,
 329                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 330 }
 331 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 332
 333 /**
 334  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 335  * @substream: PCM substream
 336  */
 337 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 338 {
 339         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 340
 341         kfree(prtd);
 342
 343         return 0;
 344 }
 345 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 346
 347 /**
 348  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 349  * @substream: PCM substream
 350  *
 351  * Releases the DMA channel associated with the PCM substream.
 352  */
 353 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 354 {
 355         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 356
 357         dma_release_channel(prtd->dma_chan);
 358
 359         return snd_dmaengine_pcm_close(substream);
 360 }
 361 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 362
 363 MODULE_LICENSE("GPL");