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 = params_physical_width(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 == 24)
  76                 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
  77         else if (bits <= 32)
  78                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  79         else
  80                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  81
  82         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  83                 slave_config->direction = DMA_MEM_TO_DEV;
  84                 slave_config->dst_addr_width = buswidth;
  85         } else {
  86                 slave_config->direction = DMA_DEV_TO_MEM;
  87                 slave_config->src_addr_width = buswidth;
  88         }
  89
  90         slave_config->device_fc = false;
  91
  92         return 0;
  93 }
  94 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  95
  96 /**
  97  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  98  *  using DAI DMA data.
  99  * @substream: PCM substream
 100  * @dma_data: DAI DMA data
 101  * @slave_config: DMA slave configuration
 102  *
 103  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
 104  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
 105  * data struct. The src and dst fields will be initialized depending on the
 106  * direction of the substream. If the substream is a playback stream the dst
 107  * fields will be initialized, if it is a capture stream the src fields will be
 108  * initialized. The {dst,src}_addr_width field will only be initialized if the
 109  * addr_width field of the DAI DMA data struct is not equal to
 110  * DMA_SLAVE_BUSWIDTH_UNDEFINED.
 111  */
 112 void snd_dmaengine_pcm_set_config_from_dai_data(
 113         const struct snd_pcm_substream *substream,
 114         const struct snd_dmaengine_dai_dma_data *dma_data,
 115         struct dma_slave_config *slave_config)
 116 {
 117         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 118                 slave_config->dst_addr = dma_data->addr;
 119                 slave_config->dst_maxburst = dma_data->maxburst;
 120                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 121                         slave_config->dst_addr_width = dma_data->addr_width;
 122         } else {
 123                 slave_config->src_addr = dma_data->addr;
 124                 slave_config->src_maxburst = dma_data->maxburst;
 125                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 126                         slave_config->src_addr_width = dma_data->addr_width;
 127         }
 128
 129         slave_config->slave_id = dma_data->slave_id;
 130 }
 131 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
 132
 133 static void dmaengine_pcm_dma_complete(void *arg)
 134 {
 135         struct snd_pcm_substream *substream = arg;
 136         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 137
 138         prtd->pos += snd_pcm_lib_period_bytes(substream);
 139         if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
 140                 prtd->pos = 0;
 141
 142         snd_pcm_period_elapsed(substream);
 143 }
 144
 145 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
 146 {
 147         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 148         struct dma_chan *chan = prtd->dma_chan;
 149         struct dma_async_tx_descriptor *desc;
 150         enum dma_transfer_direction direction;
 151         unsigned long flags = DMA_CTRL_ACK;
 152
 153         direction = snd_pcm_substream_to_dma_direction(substream);
 154
 155         if (!substream->runtime->no_period_wakeup)
 156                 flags |= DMA_PREP_INTERRUPT;
 157
 158         prtd->pos = 0;
 159         desc = dmaengine_prep_dma_cyclic(chan,
 160                 substream->runtime->dma_addr,
 161                 snd_pcm_lib_buffer_bytes(substream),
 162                 snd_pcm_lib_period_bytes(substream), direction, flags);
 163
 164         if (!desc)
 165                 return -ENOMEM;
 166
 167         desc->callback = dmaengine_pcm_dma_complete;
 168         desc->callback_param = substream;
 169         prtd->cookie = dmaengine_submit(desc);
 170
 171         return 0;
 172 }
 173
 174 /**
 175  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 176  * @substream: PCM substream
 177  * @cmd: Trigger command
 178  *
 179  * Returns 0 on success, a negative error code otherwise.
 180  *
 181  * This function can be used as the PCM trigger callback for dmaengine based PCM
 182  * driver implementations.
 183  */
 184 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 185 {
 186         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 187         struct snd_pcm_runtime *runtime = substream->runtime;
 188         int ret;
 189
 190         switch (cmd) {
 191         case SNDRV_PCM_TRIGGER_START:
 192                 ret = dmaengine_pcm_prepare_and_submit(substream);
 193                 if (ret)
 194                         return ret;
 195                 dma_async_issue_pending(prtd->dma_chan);
 196                 break;
 197         case SNDRV_PCM_TRIGGER_RESUME:
 198         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 199                 dmaengine_resume(prtd->dma_chan);
 200                 break;
 201         case SNDRV_PCM_TRIGGER_SUSPEND:
 202                 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
 203                         dmaengine_pause(prtd->dma_chan);
 204                 else
 205                         dmaengine_terminate_all(prtd->dma_chan);
 206                 break;
 207         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 208                 dmaengine_pause(prtd->dma_chan);
 209                 break;
 210         case SNDRV_PCM_TRIGGER_STOP:
 211                 dmaengine_terminate_all(prtd->dma_chan);
 212                 break;
 213         default:
 214                 return -EINVAL;
 215         }
 216
 217         return 0;
 218 }
 219 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 220
 221 /**
 222  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 223  * @substream: PCM substream
 224  *
 225  * This function is deprecated and should not be used by new drivers, as its
 226  * results may be unreliable.
 227  */
 228 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 229 {
 230         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 231         return bytes_to_frames(substream->runtime, prtd->pos);
 232 }
 233 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 234
 235 /**
 236  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 237  * @substream: PCM substream
 238  *
 239  * This function can be used as the PCM pointer callback for dmaengine based PCM
 240  * driver implementations.
 241  */
 242 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 243 {
 244         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 245         struct dma_tx_state state;
 246         enum dma_status status;
 247         unsigned int buf_size;
 248         unsigned int pos = 0;
 249
 250         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 251         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 252                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 253                 if (state.residue > 0 && state.residue <= buf_size)
 254                         pos = buf_size - state.residue;
 255         }
 256
 257         return bytes_to_frames(substream->runtime, pos);
 258 }
 259 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 260
 261 /**
 262  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 263  * @filter_fn: Filter function used to request the DMA channel
 264  * @filter_data: Data passed to the DMA filter function
 265  *
 266  * Returns NULL or the requested DMA channel.
 267  *
 268  * This function request a DMA channel for usage with dmaengine PCM.
 269  */
 270 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 271         void *filter_data)
 272 {
 273         dma_cap_mask_t mask;
 274
 275         dma_cap_zero(mask);
 276         dma_cap_set(DMA_SLAVE, mask);
 277         dma_cap_set(DMA_CYCLIC, mask);
 278
 279         return dma_request_channel(mask, filter_fn, filter_data);
 280 }
 281 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 282
 283 /**
 284  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 285  * @substream: PCM substream
 286  * @chan: DMA channel to use for data transfers
 287  *
 288  * Returns 0 on success, a negative error code otherwise.
 289  *
 290  * The function should usually be called from the pcm open callback. Note that
 291  * this function will use private_data field of the substream's runtime. So it
 292  * is not availabe to your pcm driver implementation.
 293  */
 294 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 295         struct dma_chan *chan)
 296 {
 297         struct dmaengine_pcm_runtime_data *prtd;
 298         int ret;
 299
 300         if (!chan)
 301                 return -ENXIO;
 302
 303         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 304                                             SNDRV_PCM_HW_PARAM_PERIODS);
 305         if (ret < 0)
 306                 return ret;
 307
 308         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 309         if (!prtd)
 310                 return -ENOMEM;
 311
 312         prtd->dma_chan = chan;
 313
 314         substream->runtime->private_data = prtd;
 315
 316         return 0;
 317 }
 318 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 319
 320 /**
 321  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 322  * @substream: PCM substream
 323  * @filter_fn: Filter function used to request the DMA channel
 324  * @filter_data: Data passed to the DMA filter function
 325  *
 326  * Returns 0 on success, a negative error code otherwise.
 327  *
 328  * This function will request a DMA channel using the passed filter function and
 329  * data. The function should usually be called from the pcm open callback. Note
 330  * that this function will use private_data field of the substream's runtime. So
 331  * it is not availabe to your pcm driver implementation.
 332  */
 333 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 334         dma_filter_fn filter_fn, void *filter_data)
 335 {
 336         return snd_dmaengine_pcm_open(substream,
 337                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 338 }
 339 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 340
 341 /**
 342  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 343  * @substream: PCM substream
 344  */
 345 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 346 {
 347         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 348
 349         kfree(prtd);
 350
 351         return 0;
 352 }
 353 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 354
 355 /**
 356  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 357  * @substream: PCM substream
 358  *
 359  * Releases the DMA channel associated with the PCM substream.
 360  */
 361 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 362 {
 363         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 364
 365         dma_release_channel(prtd->dma_chan);
 366
 367         return snd_dmaengine_pcm_close(substream);
 368 }
 369 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 370
 371 MODULE_LICENSE("GPL");