pcm_dmaengine.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (C) 2012, Analog Devices Inc.
   4  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   5  *
   6  *  Based on:
   7  *      imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   8  *      mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
   9  *      ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
  10  *                    Copyright (C) 2006 Applied Data Systems
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/slab.h>
  16 #include <sound/pcm.h>
  17 #include <sound/pcm_params.h>
  18 #include <sound/soc.h>
  19
  20 #include <sound/dmaengine_pcm.h>
  21
  22 struct dmaengine_pcm_runtime_data {
  23         struct dma_chan *dma_chan;
  24         dma_cookie_t cookie;
  25
  26         unsigned int pos;
  27 };
  28
  29 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  30         const struct snd_pcm_substream *substream)
  31 {
  32         return substream->runtime->private_data;
  33 }
  34
  35 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  36 {
  37         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  38
  39         return prtd->dma_chan;
  40 }
  41 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  42
  43 /**
  44  * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  45  * @substream: PCM substream
  46  * @params: hw_params
  47  * @slave_config: DMA slave config
  48  *
  49  * This function can be used to initialize a dma_slave_config from a substream
  50  * and hw_params in a dmaengine based PCM driver implementation.
  51  */
  52 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  53         const struct snd_pcm_hw_params *params,
  54         struct dma_slave_config *slave_config)
  55 {
  56         enum dma_slave_buswidth buswidth;
  57         int bits;
  58
  59         bits = params_physical_width(params);
  60         if (bits < 8 || bits > 64)
  61                 return -EINVAL;
  62         else if (bits == 8)
  63                 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  64         else if (bits == 16)
  65                 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  66         else if (bits == 24)
  67                 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
  68         else if (bits <= 32)
  69                 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  70         else
  71                 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
  72
  73         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  74                 slave_config->direction = DMA_MEM_TO_DEV;
  75                 slave_config->dst_addr_width = buswidth;
  76         } else {
  77                 slave_config->direction = DMA_DEV_TO_MEM;
  78                 slave_config->src_addr_width = buswidth;
  79         }
  80
  81         slave_config->device_fc = false;
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  86
  87 /**
  88  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  89  *  using DAI DMA data.
  90  * @substream: PCM substream
  91  * @dma_data: DAI DMA data
  92  * @slave_config: DMA slave configuration
  93  *
  94  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
  95  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
  96  * data struct. The src and dst fields will be initialized depending on the
  97  * direction of the substream. If the substream is a playback stream the dst
  98  * fields will be initialized, if it is a capture stream the src fields will be
  99  * initialized. The {dst,src}_addr_width field will only be initialized if the
 100  * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
 101  * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
 102  * both conditions are met the latter takes priority.
 103  */
 104 void snd_dmaengine_pcm_set_config_from_dai_data(
 105         const struct snd_pcm_substream *substream,
 106         const struct snd_dmaengine_dai_dma_data *dma_data,
 107         struct dma_slave_config *slave_config)
 108 {
 109         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 110                 slave_config->dst_addr = dma_data->addr;
 111                 slave_config->dst_maxburst = dma_data->maxburst;
 112                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 113                         slave_config->dst_addr_width =
 114                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 115                 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
 116                         slave_config->dst_addr_width = dma_data->addr_width;
 117         } else {
 118                 slave_config->src_addr = dma_data->addr;
 119                 slave_config->src_maxburst = dma_data->maxburst;
 120                 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
 121                         slave_config->src_addr_width =
 122                                 DMA_SLAVE_BUSWIDTH_UNDEFINED;
 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         unsigned int new_pos;
 134         struct snd_pcm_substream *substream = arg;
 135         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 136
 137         new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
 138         if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
 139                 new_pos = 0;
 140         prtd->pos = new_pos;
 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_async(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_async(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 available 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 available 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         dmaengine_synchronize(prtd->dma_chan);
 350         kfree(prtd);
 351
 352         return 0;
 353 }
 354 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 355
 356 /**
 357  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
 358  * @substream: PCM substream
 359  *
 360  * Releases the DMA channel associated with the PCM substream.
 361  */
 362 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 363 {
 364         struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
 365
 366         dmaengine_synchronize(prtd->dma_chan);
 367         dma_release_channel(prtd->dma_chan);
 368         kfree(prtd);
 369
 370         return 0;
 371 }
 372 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
 373
 374 MODULE_LICENSE("GPL");