drivers/media/pci/ivtv/ivtv-alsa-pcm.c

   1 /*
   2  *  ALSA PCM device for the
   3  *  ALSA interface to ivtv PCM capture streams
   4  *
   5  *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
   6  *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
   7  *
   8  *  Portions of this work were sponsored by ONELAN Limited for the cx18 driver
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  23  *  02111-1307  USA
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/vmalloc.h>
  29
  30 #include <media/v4l2-device.h>
  31
  32 #include <sound/core.h>
  33 #include <sound/pcm.h>
  34
  35 #include "ivtv-driver.h"
  36 #include "ivtv-queue.h"
  37 #include "ivtv-streams.h"
  38 #include "ivtv-fileops.h"
  39 #include "ivtv-alsa.h"
  40 #include "ivtv-alsa-pcm.h"
  41
  42 static unsigned int pcm_debug;
  43 module_param(pcm_debug, int, 0644);
  44 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  45
  46 #define dprintk(fmt, arg...) \
  47         do { \
  48                 if (pcm_debug) \
  49                         pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
  50         } while (0)
  51
  52 static struct snd_pcm_hardware snd_ivtv_hw_capture = {
  53         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  54                 SNDRV_PCM_INFO_MMAP           |
  55                 SNDRV_PCM_INFO_INTERLEAVED    |
  56                 SNDRV_PCM_INFO_MMAP_VALID,
  57
  58         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  59
  60         .rates = SNDRV_PCM_RATE_48000,
  61
  62         .rate_min = 48000,
  63         .rate_max = 48000,
  64         .channels_min = 2,
  65         .channels_max = 2,
  66         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  67         .period_bytes_min = 64,         /* 12544/2, */
  68         .period_bytes_max = 12544,
  69         .periods_min = 2,
  70         .periods_max = 98,              /* 12544, */
  71 };
  72
  73 static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
  74                                         u8 *pcm_data,
  75                                         size_t num_bytes)
  76 {
  77         struct snd_pcm_substream *substream;
  78         struct snd_pcm_runtime *runtime;
  79         unsigned int oldptr;
  80         unsigned int stride;
  81         int period_elapsed = 0;
  82         int length;
  83
  84         dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
  85                 pcm_data, num_bytes);
  86
  87         substream = itvsc->capture_pcm_substream;
  88         if (substream == NULL) {
  89                 dprintk("substream was NULL\n");
  90                 return;
  91         }
  92
  93         runtime = substream->runtime;
  94         if (runtime == NULL) {
  95                 dprintk("runtime was NULL\n");
  96                 return;
  97         }
  98
  99         stride = runtime->frame_bits >> 3;
 100         if (stride == 0) {
 101                 dprintk("stride is zero\n");
 102                 return;
 103         }
 104
 105         length = num_bytes / stride;
 106         if (length == 0) {
 107                 dprintk("%s: length was zero\n", __func__);
 108                 return;
 109         }
 110
 111         if (runtime->dma_area == NULL) {
 112                 dprintk("dma area was NULL - ignoring\n");
 113                 return;
 114         }
 115
 116         oldptr = itvsc->hwptr_done_capture;
 117         if (oldptr + length >= runtime->buffer_size) {
 118                 unsigned int cnt =
 119                         runtime->buffer_size - oldptr;
 120                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 121                        cnt * stride);
 122                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 123                        length * stride - cnt * stride);
 124         } else {
 125                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 126                        length * stride);
 127         }
 128         snd_pcm_stream_lock(substream);
 129
 130         itvsc->hwptr_done_capture += length;
 131         if (itvsc->hwptr_done_capture >=
 132             runtime->buffer_size)
 133                 itvsc->hwptr_done_capture -=
 134                         runtime->buffer_size;
 135
 136         itvsc->capture_transfer_done += length;
 137         if (itvsc->capture_transfer_done >=
 138             runtime->period_size) {
 139                 itvsc->capture_transfer_done -=
 140                         runtime->period_size;
 141                 period_elapsed = 1;
 142         }
 143
 144         snd_pcm_stream_unlock(substream);
 145
 146         if (period_elapsed)
 147                 snd_pcm_period_elapsed(substream);
 148 }
 149
 150 static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
 151 {
 152         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 153         struct snd_pcm_runtime *runtime = substream->runtime;
 154         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 155         struct ivtv *itv = to_ivtv(v4l2_dev);
 156         struct ivtv_stream *s;
 157         struct ivtv_open_id item;
 158         int ret;
 159
 160         /* Instruct the CX2341[56] to start sending packets */
 161         snd_ivtv_lock(itvsc);
 162
 163         if (ivtv_init_on_first_open(itv)) {
 164                 snd_ivtv_unlock(itvsc);
 165                 return -ENXIO;
 166         }
 167
 168         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 169
 170         v4l2_fh_init(&item.fh, &s->vdev);
 171         item.itv = itv;
 172         item.type = s->type;
 173
 174         /* See if the stream is available */
 175         if (ivtv_claim_stream(&item, item.type)) {
 176                 /* No, it's already in use */
 177                 snd_ivtv_unlock(itvsc);
 178                 return -EBUSY;
 179         }
 180
 181         if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
 182             test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
 183                 /* We're already streaming.  No additional action required */
 184                 snd_ivtv_unlock(itvsc);
 185                 return 0;
 186         }
 187
 188
 189         runtime->hw = snd_ivtv_hw_capture;
 190         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 191         itvsc->capture_pcm_substream = substream;
 192         runtime->private_data = itv;
 193
 194         itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
 195
 196         /* Not currently streaming, so start it up */
 197         set_bit(IVTV_F_S_STREAMING, &s->s_flags);
 198         ret = ivtv_start_v4l2_encode_stream(s);
 199         snd_ivtv_unlock(itvsc);
 200
 201         return ret;
 202 }
 203
 204 static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
 205 {
 206         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 207         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 208         struct ivtv *itv = to_ivtv(v4l2_dev);
 209         struct ivtv_stream *s;
 210
 211         /* Instruct the ivtv to stop sending packets */
 212         snd_ivtv_lock(itvsc);
 213         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 214         ivtv_stop_v4l2_encode_stream(s, 0);
 215         clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
 216
 217         ivtv_release_stream(s);
 218
 219         itv->pcm_announce_callback = NULL;
 220         snd_ivtv_unlock(itvsc);
 221
 222         return 0;
 223 }
 224
 225 static int snd_ivtv_pcm_ioctl(struct snd_pcm_substream *substream,
 226                      unsigned int cmd, void *arg)
 227 {
 228         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 229         int ret;
 230
 231         snd_ivtv_lock(itvsc);
 232         ret = snd_pcm_lib_ioctl(substream, cmd, arg);
 233         snd_ivtv_unlock(itvsc);
 234         return ret;
 235 }
 236
 237
 238 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
 239                                         size_t size)
 240 {
 241         struct snd_pcm_runtime *runtime = subs->runtime;
 242
 243         dprintk("Allocating vbuffer\n");
 244         if (runtime->dma_area) {
 245                 if (runtime->dma_bytes > size)
 246                         return 0;
 247
 248                 vfree(runtime->dma_area);
 249         }
 250         runtime->dma_area = vmalloc(size);
 251         if (!runtime->dma_area)
 252                 return -ENOMEM;
 253
 254         runtime->dma_bytes = size;
 255
 256         return 0;
 257 }
 258
 259 static int snd_ivtv_pcm_hw_params(struct snd_pcm_substream *substream,
 260                          struct snd_pcm_hw_params *params)
 261 {
 262         dprintk("%s called\n", __func__);
 263
 264         return snd_pcm_alloc_vmalloc_buffer(substream,
 265                                            params_buffer_bytes(params));
 266 }
 267
 268 static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream)
 269 {
 270         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 271         unsigned long flags;
 272
 273         spin_lock_irqsave(&itvsc->slock, flags);
 274         if (substream->runtime->dma_area) {
 275                 dprintk("freeing pcm capture region\n");
 276                 vfree(substream->runtime->dma_area);
 277                 substream->runtime->dma_area = NULL;
 278         }
 279         spin_unlock_irqrestore(&itvsc->slock, flags);
 280
 281         return 0;
 282 }
 283
 284 static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
 285 {
 286         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 287
 288         itvsc->hwptr_done_capture = 0;
 289         itvsc->capture_transfer_done = 0;
 290
 291         return 0;
 292 }
 293
 294 static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 295 {
 296         return 0;
 297 }
 298
 299 static
 300 snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
 301 {
 302         unsigned long flags;
 303         snd_pcm_uframes_t hwptr_done;
 304         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 305
 306         spin_lock_irqsave(&itvsc->slock, flags);
 307         hwptr_done = itvsc->hwptr_done_capture;
 308         spin_unlock_irqrestore(&itvsc->slock, flags);
 309
 310         return hwptr_done;
 311 }
 312
 313 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 314                                              unsigned long offset)
 315 {
 316         void *pageptr = subs->runtime->dma_area + offset;
 317
 318         return vmalloc_to_page(pageptr);
 319 }
 320
 321 static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
 322         .open           = snd_ivtv_pcm_capture_open,
 323         .close          = snd_ivtv_pcm_capture_close,
 324         .ioctl          = snd_ivtv_pcm_ioctl,
 325         .hw_params      = snd_ivtv_pcm_hw_params,
 326         .hw_free        = snd_ivtv_pcm_hw_free,
 327         .prepare        = snd_ivtv_pcm_prepare,
 328         .trigger        = snd_ivtv_pcm_trigger,
 329         .pointer        = snd_ivtv_pcm_pointer,
 330         .page           = snd_pcm_get_vmalloc_page,
 331 };
 332
 333 int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
 334 {
 335         struct snd_pcm *sp;
 336         struct snd_card *sc = itvsc->sc;
 337         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 338         struct ivtv *itv = to_ivtv(v4l2_dev);
 339         int ret;
 340
 341         ret = snd_pcm_new(sc, "CX2341[56] PCM",
 342                           0, /* PCM device 0, the only one for this card */
 343                           0, /* 0 playback substreams */
 344                           1, /* 1 capture substream */
 345                           &sp);
 346         if (ret) {
 347                 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
 348                               __func__, ret);
 349                 goto err_exit;
 350         }
 351
 352         spin_lock_init(&itvsc->slock);
 353
 354         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 355                         &snd_ivtv_pcm_capture_ops);
 356         sp->info_flags = 0;
 357         sp->private_data = itvsc;
 358         strlcpy(sp->name, itv->card_name, sizeof(sp->name));
 359
 360         return 0;
 361
 362 err_exit:
 363         return ret;
 364 }