sound/soc/omap/omap-pcm.c

   1 /*
   2  * omap-pcm.c  --  ALSA PCM interface for the OMAP SoC
   3  *
   4  * Copyright (C) 2008 Nokia Corporation
   5  *
   6  * Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/dma-mapping.h>
  25 #include <sound/core.h>
  26 #include <sound/pcm.h>
  27 #include <sound/pcm_params.h>
  28 #include <sound/soc.h>
  29
  30 #include <mach/dma.h>
  31 #include "omap-pcm.h"
  32
  33 static const struct snd_pcm_hardware omap_pcm_hardware = {
  34         .info                   = SNDRV_PCM_INFO_MMAP |
  35                                   SNDRV_PCM_INFO_MMAP_VALID |
  36                                   SNDRV_PCM_INFO_INTERLEAVED |
  37                                   SNDRV_PCM_INFO_PAUSE |
  38                                   SNDRV_PCM_INFO_RESUME,
  39         .formats                = SNDRV_PCM_FMTBIT_S16_LE,
  40         .period_bytes_min       = 32,
  41         .period_bytes_max       = 64 * 1024,
  42         .periods_min            = 2,
  43         .periods_max            = 255,
  44         .buffer_bytes_max       = 128 * 1024,
  45 };
  46
  47 struct omap_runtime_data {
  48         spinlock_t                      lock;
  49         struct omap_pcm_dma_data        *dma_data;
  50         int                             dma_ch;
  51         int                             period_index;
  52 };
  53
  54 static void omap_pcm_dma_irq(int ch, u16 stat, void *data)
  55 {
  56         struct snd_pcm_substream *substream = data;
  57         struct snd_pcm_runtime *runtime = substream->runtime;
  58         struct omap_runtime_data *prtd = runtime->private_data;
  59         unsigned long flags;
  60
  61         if (cpu_is_omap1510()) {
  62                 /*
  63                  * OMAP1510 doesn't support DMA chaining so have to restart
  64                  * the transfer after all periods are transferred
  65                  */
  66                 spin_lock_irqsave(&prtd->lock, flags);
  67                 if (prtd->period_index >= 0) {
  68                         if (++prtd->period_index == runtime->periods) {
  69                                 prtd->period_index = 0;
  70                                 omap_start_dma(prtd->dma_ch);
  71                         }
  72                 }
  73                 spin_unlock_irqrestore(&prtd->lock, flags);
  74         }
  75
  76         snd_pcm_period_elapsed(substream);
  77 }
  78
  79 /* this may get called several times by oss emulation */
  80 static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
  81                               struct snd_pcm_hw_params *params)
  82 {
  83         struct snd_pcm_runtime *runtime = substream->runtime;
  84         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  85         struct omap_runtime_data *prtd = runtime->private_data;
  86         struct omap_pcm_dma_data *dma_data = rtd->dai->cpu_dai->dma_data;
  87         int err = 0;
  88
  89         if (!dma_data)
  90                 return -ENODEV;
  91
  92         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
  93         runtime->dma_bytes = params_buffer_bytes(params);
  94
  95         if (prtd->dma_data)
  96                 return 0;
  97         prtd->dma_data = dma_data;
  98         err = omap_request_dma(dma_data->dma_req, dma_data->name,
  99                                omap_pcm_dma_irq, substream, &prtd->dma_ch);
 100         if (!err & !cpu_is_omap1510()) {
 101                 /*
 102                  * Link channel with itself so DMA doesn't need any
 103                  * reprogramming while looping the buffer
 104                  */
 105                 omap_dma_link_lch(prtd->dma_ch, prtd->dma_ch);
 106         }
 107
 108         return err;
 109 }
 110
 111 static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
 112 {
 113         struct snd_pcm_runtime *runtime = substream->runtime;
 114         struct omap_runtime_data *prtd = runtime->private_data;
 115
 116         if (prtd->dma_data == NULL)
 117                 return 0;
 118
 119         if (!cpu_is_omap1510())
 120                 omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
 121         omap_free_dma(prtd->dma_ch);
 122         prtd->dma_data = NULL;
 123
 124         snd_pcm_set_runtime_buffer(substream, NULL);
 125
 126         return 0;
 127 }
 128
 129 static int omap_pcm_prepare(struct snd_pcm_substream *substream)
 130 {
 131         struct snd_pcm_runtime *runtime = substream->runtime;
 132         struct omap_runtime_data *prtd = runtime->private_data;
 133         struct omap_pcm_dma_data *dma_data = prtd->dma_data;
 134         struct omap_dma_channel_params dma_params;
 135
 136         memset(&dma_params, 0, sizeof(dma_params));
 137         /*
 138          * Note: Regardless of interface data formats supported by OMAP McBSP
 139          * or EAC blocks, internal representation is always fixed 16-bit/sample
 140          */
 141         dma_params.data_type                    = OMAP_DMA_DATA_TYPE_S16;
 142         dma_params.trigger                      = dma_data->dma_req;
 143         dma_params.sync_mode                    = OMAP_DMA_SYNC_ELEMENT;
 144         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 145                 dma_params.src_amode            = OMAP_DMA_AMODE_POST_INC;
 146                 dma_params.dst_amode            = OMAP_DMA_AMODE_CONSTANT;
 147                 dma_params.src_or_dst_synch     = OMAP_DMA_DST_SYNC;
 148                 dma_params.src_start            = runtime->dma_addr;
 149                 dma_params.dst_start            = dma_data->port_addr;
 150                 dma_params.dst_port             = OMAP_DMA_PORT_MPUI;
 151         } else {
 152                 dma_params.src_amode            = OMAP_DMA_AMODE_CONSTANT;
 153                 dma_params.dst_amode            = OMAP_DMA_AMODE_POST_INC;
 154                 dma_params.src_or_dst_synch     = OMAP_DMA_SRC_SYNC;
 155                 dma_params.src_start            = dma_data->port_addr;
 156                 dma_params.dst_start            = runtime->dma_addr;
 157                 dma_params.src_port             = OMAP_DMA_PORT_MPUI;
 158         }
 159         /*
 160          * Set DMA transfer frame size equal to ALSA period size and frame
 161          * count as no. of ALSA periods. Then with DMA frame interrupt enabled,
 162          * we can transfer the whole ALSA buffer with single DMA transfer but
 163          * still can get an interrupt at each period bounary
 164          */
 165         dma_params.elem_count   = snd_pcm_lib_period_bytes(substream) / 2;
 166         dma_params.frame_count  = runtime->periods;
 167         omap_set_dma_params(prtd->dma_ch, &dma_params);
 168
 169         omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ);
 170
 171         /*
 172          * To handle realtime streaming sources properly, we need to be sure
 173          * we have at least 2 periods of size larger than FIFO in the buffer
 174          * to start playing without underflowing. This is because DMA is always
 175          * ahead of playback by amount close to FIFO size and needs to have
 176          * next period ready when previous one finishes transfering to FIFO.
 177          */
 178         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 179             runtime->periods > 1) {
 180                 struct snd_soc_pcm_runtime *rtd = substream->private_data;
 181                 int *mcbsp_bus_id = rtd->dai->cpu_dai->private_data;
 182                 int fifo_samples = (*mcbsp_bus_id == 1) ? 1024 : 256;
 183                 int period_samples, period_frames;
 184
 185                 period_samples = bytes_to_samples(runtime,
 186                                 snd_pcm_lib_period_bytes(substream));
 187                 if (period_samples < fifo_samples + runtime->channels)
 188                         period_samples = fifo_samples + runtime->channels;
 189                 period_frames = bytes_to_frames(runtime,
 190                                 samples_to_bytes(runtime, period_samples)) * 2;
 191
 192                 if (runtime->start_threshold < period_frames)
 193                         runtime->start_threshold = period_frames;
 194         }
 195
 196         return 0;
 197 }
 198
 199 static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 200 {
 201         struct snd_pcm_runtime *runtime = substream->runtime;
 202         struct omap_runtime_data *prtd = runtime->private_data;
 203         int ret = 0;
 204
 205         spin_lock_irq(&prtd->lock);
 206         switch (cmd) {
 207         case SNDRV_PCM_TRIGGER_START:
 208         case SNDRV_PCM_TRIGGER_RESUME:
 209         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 210                 prtd->period_index = 0;
 211                 omap_start_dma(prtd->dma_ch);
 212                 break;
 213
 214         case SNDRV_PCM_TRIGGER_STOP:
 215         case SNDRV_PCM_TRIGGER_SUSPEND:
 216         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 217                 prtd->period_index = -1;
 218                 omap_stop_dma(prtd->dma_ch);
 219                 break;
 220         default:
 221                 ret = -EINVAL;
 222         }
 223         spin_unlock_irq(&prtd->lock);
 224
 225         return ret;
 226 }
 227
 228 static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
 229 {
 230         struct snd_pcm_runtime *runtime = substream->runtime;
 231         struct omap_runtime_data *prtd = runtime->private_data;
 232         dma_addr_t ptr;
 233         snd_pcm_uframes_t offset;
 234
 235         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 236                 ptr = omap_get_dma_src_pos(prtd->dma_ch);
 237         else
 238                 ptr = omap_get_dma_dst_pos(prtd->dma_ch);
 239
 240         offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
 241         if (offset >= runtime->buffer_size)
 242                 offset = 0;
 243
 244         return offset;
 245 }
 246
 247 static int omap_pcm_open(struct snd_pcm_substream *substream)
 248 {
 249         struct snd_pcm_runtime *runtime = substream->runtime;
 250         struct omap_runtime_data *prtd;
 251         int ret;
 252
 253         snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);
 254
 255         /* Ensure that buffer size is a multiple of period size */
 256         ret = snd_pcm_hw_constraint_integer(runtime,
 257                                             SNDRV_PCM_HW_PARAM_PERIODS);
 258         if (ret < 0)
 259                 goto out;
 260
 261         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 262         if (prtd == NULL) {
 263                 ret = -ENOMEM;
 264                 goto out;
 265         }
 266         spin_lock_init(&prtd->lock);
 267         runtime->private_data = prtd;
 268
 269 out:
 270         return ret;
 271 }
 272
 273 static int omap_pcm_close(struct snd_pcm_substream *substream)
 274 {
 275         struct snd_pcm_runtime *runtime = substream->runtime;
 276
 277         kfree(runtime->private_data);
 278         return 0;
 279 }
 280
 281 static int omap_pcm_mmap(struct snd_pcm_substream *substream,
 282         struct vm_area_struct *vma)
 283 {
 284         struct snd_pcm_runtime *runtime = substream->runtime;
 285
 286         return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 287                                      runtime->dma_area,
 288                                      runtime->dma_addr,
 289                                      runtime->dma_bytes);
 290 }
 291
 292 struct snd_pcm_ops omap_pcm_ops = {
 293         .open           = omap_pcm_open,
 294         .close          = omap_pcm_close,
 295         .ioctl          = snd_pcm_lib_ioctl,
 296         .hw_params      = omap_pcm_hw_params,
 297         .hw_free        = omap_pcm_hw_free,
 298         .prepare        = omap_pcm_prepare,
 299         .trigger        = omap_pcm_trigger,
 300         .pointer        = omap_pcm_pointer,
 301         .mmap           = omap_pcm_mmap,
 302 };
 303
 304 static u64 omap_pcm_dmamask = DMA_BIT_MASK(32);
 305
 306 static int omap_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
 307         int stream)
 308 {
 309         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 310         struct snd_dma_buffer *buf = &substream->dma_buffer;
 311         size_t size = omap_pcm_hardware.buffer_bytes_max;
 312
 313         buf->dev.type = SNDRV_DMA_TYPE_DEV;
 314         buf->dev.dev = pcm->card->dev;
 315         buf->private_data = NULL;
 316         buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 317                                            &buf->addr, GFP_KERNEL);
 318         if (!buf->area)
 319                 return -ENOMEM;
 320
 321         buf->bytes = size;
 322         return 0;
 323 }
 324
 325 static void omap_pcm_free_dma_buffers(struct snd_pcm *pcm)
 326 {
 327         struct snd_pcm_substream *substream;
 328         struct snd_dma_buffer *buf;
 329         int stream;
 330
 331         for (stream = 0; stream < 2; stream++) {
 332                 substream = pcm->streams[stream].substream;
 333                 if (!substream)
 334                         continue;
 335
 336                 buf = &substream->dma_buffer;
 337                 if (!buf->area)
 338                         continue;
 339
 340                 dma_free_writecombine(pcm->card->dev, buf->bytes,
 341                                       buf->area, buf->addr);
 342                 buf->area = NULL;
 343         }
 344 }
 345
 346 int omap_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
 347                  struct snd_pcm *pcm)
 348 {
 349         int ret = 0;
 350
 351         if (!card->dev->dma_mask)
 352                 card->dev->dma_mask = &omap_pcm_dmamask;
 353         if (!card->dev->coherent_dma_mask)
 354                 card->dev->coherent_dma_mask = DMA_32BIT_MASK;
 355
 356         if (dai->playback.channels_min) {
 357                 ret = omap_pcm_preallocate_dma_buffer(pcm,
 358                         SNDRV_PCM_STREAM_PLAYBACK);
 359                 if (ret)
 360                         goto out;
 361         }
 362
 363         if (dai->capture.channels_min) {
 364                 ret = omap_pcm_preallocate_dma_buffer(pcm,
 365                         SNDRV_PCM_STREAM_CAPTURE);
 366                 if (ret)
 367                         goto out;
 368         }
 369
 370 out:
 371         return ret;
 372 }
 373
 374 struct snd_soc_platform omap_soc_platform = {
 375         .name           = "omap-pcm-audio",
 376         .pcm_ops        = &omap_pcm_ops,
 377         .pcm_new        = omap_pcm_new,
 378         .pcm_free       = omap_pcm_free_dma_buffers,
 379 };
 380 EXPORT_SYMBOL_GPL(omap_soc_platform);
 381
 382 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@nokia.com>");
 383 MODULE_DESCRIPTION("OMAP PCM DMA module");
 384 MODULE_LICENSE("GPL");