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         struct snd_pcm_runtime *runtime = substream->runtime;
 186         int ret;
 187
 188         switch (cmd) {
 189         case SNDRV_PCM_TRIGGER_START:
 190                 ret = dmaengine_pcm_prepare_and_submit(substream);
 191                 if (ret)
 192                         return ret;
 193                 dma_async_issue_pending(prtd->dma_chan);
 194                 break;
 195         case SNDRV_PCM_TRIGGER_RESUME:
 196         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 197                 dmaengine_resume(prtd->dma_chan);
 198                 break;
 199         case SNDRV_PCM_TRIGGER_SUSPEND:
 200                 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
 201                         dmaengine_pause(prtd->dma_chan);
 202                 else
 203                         dmaengine_terminate_all(prtd->dma_chan);
 204                 break;
 205         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 206                 dmaengine_pause(prtd->dma_chan);
 207                 break;
 208         case SNDRV_PCM_TRIGGER_STOP:
 209                 dmaengine_terminate_all(prtd->dma_chan);
 210                 break;
 211         default:
 212                 return -EINVAL;
 213         }
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
 218
 219 /**
 220  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
 221  * @substream: PCM substream
 222  *
 223  * This function is deprecated and should not be used by new drivers, as its
 224  * results may be unreliable.
 225  */
 226 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
 227 {
 228         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 229         return bytes_to_frames(substream->runtime, prtd->pos);
 230 }
 231 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
 232
 233 /**
 234  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 235  * @substream: PCM substream
 236  *
 237  * This function can be used as the PCM pointer callback for dmaengine based PCM
 238  * driver implementations.
 239  */
 240 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 241 {
 242         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 243         struct dma_tx_state state;
 244         enum dma_status status;
 245         unsigned int buf_size;
 246         unsigned int pos = 0;
 247
 248         status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 249         if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
 250                 buf_size = snd_pcm_lib_buffer_bytes(substream);
 251                 if (state.residue > 0 && state.residue <= buf_size)
 252                         pos = buf_size - state.residue;
 253         }
 254
 255         return bytes_to_frames(substream->runtime, pos);
 256 }
 257 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
 258
 259 /**
 260  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
 261  * @filter_fn: Filter function used to request the DMA channel
 262  * @filter_data: Data passed to the DMA filter function
 263  *
 264  * Returns NULL or the requested DMA channel.
 265  *
 266  * This function request a DMA channel for usage with dmaengine PCM.
 267  */
 268 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 269         void *filter_data)
 270 {
 271         dma_cap_mask_t mask;
 272
 273         dma_cap_zero(mask);
 274         dma_cap_set(DMA_SLAVE, mask);
 275         dma_cap_set(DMA_CYCLIC, mask);
 276
 277         return dma_request_channel(mask, filter_fn, filter_data);
 278 }
 279 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
 280
 281 /**
 282  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 283  * @substream: PCM substream
 284  * @chan: DMA channel to use for data transfers
 285  *
 286  * Returns 0 on success, a negative error code otherwise.
 287  *
 288  * The function should usually be called from the pcm open callback. Note that
 289  * this function will use private_data field of the substream's runtime. So it
 290  * is not availabe to your pcm driver implementation.
 291  */
 292 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 293         struct dma_chan *chan)
 294 {
 295         struct dmaengine_pcm_runtime_data *prtd;
 296         int ret;
 297
 298         if (!chan)
 299                 return -ENXIO;
 300
 301         ret = snd_pcm_hw_constraint_integer(substream->runtime,
 302                                             SNDRV_PCM_HW_PARAM_PERIODS);
 303         if (ret < 0)
 304                 return ret;
 305
 306         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 307         if (!prtd)
 308                 return -ENOMEM;
 309
 310         prtd->dma_chan = chan;
 311
 312         substream->runtime->private_data = prtd;
 313
 314         return 0;
 315 }
 316 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
 317
 318 /**
 319  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
 320  * @substream: PCM substream
 321  * @filter_fn: Filter function used to request the DMA channel
 322  * @filter_data: Data passed to the DMA filter function
 323  *
 324  * Returns 0 on success, a negative error code otherwise.
 325  *
 326  * This function will request a DMA channel using the passed filter function and
 327  * data. The function should usually be called from the pcm open callback. Note
 328  * that this function will use private_data field of the substream's runtime. So
 329  * it is not availabe to your pcm driver implementation.
 330  */
 331 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
 332         dma_filter_fn filter_fn, void *filter_data)
 333 {
 334         return snd_dmaengine_pcm_open(substream,
 335                     snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
 336 }
 337 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 338
 339 /**
 340  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 341  * @substream: PCM substream
 342  */
 343 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 344 {
 345         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 346
 347         kfree(prtd);
 348
 349         return 0;
 350 }
 351 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 352
 353 /**
 354  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 355  * @substream: PCM substream
 356  *
 357  * Releases the DMA channel associated with the PCM substream.
 358  */
 359 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 360 {
 361         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 362
 363         dma_release_channel(prtd->dma_chan);
 364
 365         return snd_dmaengine_pcm_close(substream);
 366 }
 367 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 368
 369 MODULE_LICENSE("GPL");