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
  21 #include "ivtv-driver.h"
  22 #include "ivtv-queue.h"
  23 #include "ivtv-streams.h"
  24 #include "ivtv-fileops.h"
  25 #include "ivtv-alsa.h"
  26 #include "ivtv-alsa-pcm.h"
  27
  28 #include <linux/vmalloc.h>
  29
  30 #include <sound/core.h>
  31 #include <sound/pcm.h>
  32
  33
  34 static unsigned int pcm_debug;
  35 module_param(pcm_debug, int, 0644);
  36 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  37
  38 #define dprintk(fmt, arg...) \
  39         do { \
  40                 if (pcm_debug) \
  41                         pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
  42         } while (0)
  43
  44 static const struct snd_pcm_hardware snd_ivtv_hw_capture = {
  45         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  46                 SNDRV_PCM_INFO_MMAP           |
  47                 SNDRV_PCM_INFO_INTERLEAVED    |
  48                 SNDRV_PCM_INFO_MMAP_VALID,
  49
  50         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  51
  52         .rates = SNDRV_PCM_RATE_48000,
  53
  54         .rate_min = 48000,
  55         .rate_max = 48000,
  56         .channels_min = 2,
  57         .channels_max = 2,
  58         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  59         .period_bytes_min = 64,         /* 12544/2, */
  60         .period_bytes_max = 12544,
  61         .periods_min = 2,
  62         .periods_max = 98,              /* 12544, */
  63 };
  64
  65 static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
  66                                         u8 *pcm_data,
  67                                         size_t num_bytes)
  68 {
  69         struct snd_pcm_substream *substream;
  70         struct snd_pcm_runtime *runtime;
  71         unsigned int oldptr;
  72         unsigned int stride;
  73         int period_elapsed = 0;
  74         int length;
  75
  76         dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
  77                 pcm_data, num_bytes);
  78
  79         substream = itvsc->capture_pcm_substream;
  80         if (substream == NULL) {
  81                 dprintk("substream was NULL\n");
  82                 return;
  83         }
  84
  85         runtime = substream->runtime;
  86         if (runtime == NULL) {
  87                 dprintk("runtime was NULL\n");
  88                 return;
  89         }
  90
  91         stride = runtime->frame_bits >> 3;
  92         if (stride == 0) {
  93                 dprintk("stride is zero\n");
  94                 return;
  95         }
  96
  97         length = num_bytes / stride;
  98         if (length == 0) {
  99                 dprintk("%s: length was zero\n", __func__);
 100                 return;
 101         }
 102
 103         if (runtime->dma_area == NULL) {
 104                 dprintk("dma area was NULL - ignoring\n");
 105                 return;
 106         }
 107
 108         oldptr = itvsc->hwptr_done_capture;
 109         if (oldptr + length >= runtime->buffer_size) {
 110                 unsigned int cnt =
 111                         runtime->buffer_size - oldptr;
 112                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 113                        cnt * stride);
 114                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 115                        length * stride - cnt * stride);
 116         } else {
 117                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 118                        length * stride);
 119         }
 120         snd_pcm_stream_lock(substream);
 121
 122         itvsc->hwptr_done_capture += length;
 123         if (itvsc->hwptr_done_capture >=
 124             runtime->buffer_size)
 125                 itvsc->hwptr_done_capture -=
 126                         runtime->buffer_size;
 127
 128         itvsc->capture_transfer_done += length;
 129         if (itvsc->capture_transfer_done >=
 130             runtime->period_size) {
 131                 itvsc->capture_transfer_done -=
 132                         runtime->period_size;
 133                 period_elapsed = 1;
 134         }
 135
 136         snd_pcm_stream_unlock(substream);
 137
 138         if (period_elapsed)
 139                 snd_pcm_period_elapsed(substream);
 140 }
 141
 142 static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
 143 {
 144         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 145         struct snd_pcm_runtime *runtime = substream->runtime;
 146         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 147         struct ivtv *itv = to_ivtv(v4l2_dev);
 148         struct ivtv_stream *s;
 149         struct ivtv_open_id item;
 150         int ret;
 151
 152         /* Instruct the CX2341[56] to start sending packets */
 153         snd_ivtv_lock(itvsc);
 154
 155         if (ivtv_init_on_first_open(itv)) {
 156                 snd_ivtv_unlock(itvsc);
 157                 return -ENXIO;
 158         }
 159
 160         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 161
 162         v4l2_fh_init(&item.fh, &s->vdev);
 163         item.itv = itv;
 164         item.type = s->type;
 165
 166         /* See if the stream is available */
 167         if (ivtv_claim_stream(&item, item.type)) {
 168                 /* No, it's already in use */
 169                 v4l2_fh_exit(&item.fh);
 170                 snd_ivtv_unlock(itvsc);
 171                 return -EBUSY;
 172         }
 173
 174         if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
 175             test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
 176                 /* We're already streaming.  No additional action required */
 177                 snd_ivtv_unlock(itvsc);
 178                 return 0;
 179         }
 180
 181
 182         runtime->hw = snd_ivtv_hw_capture;
 183         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 184         itvsc->capture_pcm_substream = substream;
 185         runtime->private_data = itv;
 186
 187         itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
 188
 189         /* Not currently streaming, so start it up */
 190         set_bit(IVTV_F_S_STREAMING, &s->s_flags);
 191         ret = ivtv_start_v4l2_encode_stream(s);
 192         snd_ivtv_unlock(itvsc);
 193
 194         return ret;
 195 }
 196
 197 static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
 198 {
 199         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 200         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 201         struct ivtv *itv = to_ivtv(v4l2_dev);
 202         struct ivtv_stream *s;
 203
 204         /* Instruct the ivtv to stop sending packets */
 205         snd_ivtv_lock(itvsc);
 206         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 207         ivtv_stop_v4l2_encode_stream(s, 0);
 208         clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
 209
 210         ivtv_release_stream(s);
 211
 212         itv->pcm_announce_callback = NULL;
 213         snd_ivtv_unlock(itvsc);
 214
 215         return 0;
 216 }
 217
 218 static int snd_ivtv_pcm_ioctl(struct snd_pcm_substream *substream,
 219                      unsigned int cmd, void *arg)
 220 {
 221         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 222         int ret;
 223
 224         snd_ivtv_lock(itvsc);
 225         ret = snd_pcm_lib_ioctl(substream, cmd, arg);
 226         snd_ivtv_unlock(itvsc);
 227         return ret;
 228 }
 229
 230
 231 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
 232                                         size_t size)
 233 {
 234         struct snd_pcm_runtime *runtime = subs->runtime;
 235
 236         dprintk("Allocating vbuffer\n");
 237         if (runtime->dma_area) {
 238                 if (runtime->dma_bytes > size)
 239                         return 0;
 240
 241                 vfree(runtime->dma_area);
 242         }
 243         runtime->dma_area = vmalloc(size);
 244         if (!runtime->dma_area)
 245                 return -ENOMEM;
 246
 247         runtime->dma_bytes = size;
 248
 249         return 0;
 250 }
 251
 252 static int snd_ivtv_pcm_hw_params(struct snd_pcm_substream *substream,
 253                          struct snd_pcm_hw_params *params)
 254 {
 255         dprintk("%s called\n", __func__);
 256
 257         return snd_pcm_alloc_vmalloc_buffer(substream,
 258                                            params_buffer_bytes(params));
 259 }
 260
 261 static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream)
 262 {
 263         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 264         unsigned long flags;
 265         unsigned char *dma_area = NULL;
 266
 267         spin_lock_irqsave(&itvsc->slock, flags);
 268         if (substream->runtime->dma_area) {
 269                 dprintk("freeing pcm capture region\n");
 270                 dma_area = substream->runtime->dma_area;
 271                 substream->runtime->dma_area = NULL;
 272         }
 273         spin_unlock_irqrestore(&itvsc->slock, flags);
 274         vfree(dma_area);
 275
 276         return 0;
 277 }
 278
 279 static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
 280 {
 281         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 282
 283         itvsc->hwptr_done_capture = 0;
 284         itvsc->capture_transfer_done = 0;
 285
 286         return 0;
 287 }
 288
 289 static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 290 {
 291         return 0;
 292 }
 293
 294 static
 295 snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
 296 {
 297         unsigned long flags;
 298         snd_pcm_uframes_t hwptr_done;
 299         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 300
 301         spin_lock_irqsave(&itvsc->slock, flags);
 302         hwptr_done = itvsc->hwptr_done_capture;
 303         spin_unlock_irqrestore(&itvsc->slock, flags);
 304
 305         return hwptr_done;
 306 }
 307
 308 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 309                                              unsigned long offset)
 310 {
 311         void *pageptr = subs->runtime->dma_area + offset;
 312
 313         return vmalloc_to_page(pageptr);
 314 }
 315
 316 static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
 317         .open           = snd_ivtv_pcm_capture_open,
 318         .close          = snd_ivtv_pcm_capture_close,
 319         .ioctl          = snd_ivtv_pcm_ioctl,
 320         .hw_params      = snd_ivtv_pcm_hw_params,
 321         .hw_free        = snd_ivtv_pcm_hw_free,
 322         .prepare        = snd_ivtv_pcm_prepare,
 323         .trigger        = snd_ivtv_pcm_trigger,
 324         .pointer        = snd_ivtv_pcm_pointer,
 325         .page           = snd_pcm_get_vmalloc_page,
 326 };
 327
 328 int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
 329 {
 330         struct snd_pcm *sp;
 331         struct snd_card *sc = itvsc->sc;
 332         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 333         struct ivtv *itv = to_ivtv(v4l2_dev);
 334         int ret;
 335
 336         ret = snd_pcm_new(sc, "CX2341[56] PCM",
 337                           0, /* PCM device 0, the only one for this card */
 338                           0, /* 0 playback substreams */
 339                           1, /* 1 capture substream */
 340                           &sp);
 341         if (ret) {
 342                 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
 343                               __func__, ret);
 344                 goto err_exit;
 345         }
 346
 347         spin_lock_init(&itvsc->slock);
 348
 349         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 350                         &snd_ivtv_pcm_capture_ops);
 351         sp->info_flags = 0;
 352         sp->private_data = itvsc;
 353         strlcpy(sp->name, itv->card_name, sizeof(sp->name));
 354
 355         return 0;
 356
 357 err_exit:
 358         return ret;
 359 }