drivers/media/video/cx18/cx18-alsa-pcm.c

   1 /*
   2  *  ALSA PCM device for the
   3  *  ALSA interface to cx18 PCM capture streams
   4  *
   5  *  Copyright (C) 2009  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.
   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 "cx18-driver.h"
  36 #include "cx18-queue.h"
  37 #include "cx18-streams.h"
  38 #include "cx18-fileops.h"
  39 #include "cx18-alsa.h"
  40
  41 static unsigned int pcm_debug;
  42 module_param(pcm_debug, int, 0644);
  43 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  44
  45 #define dprintk(fmt, arg...) do {                                       \
  46             if (pcm_debug)                                              \
  47                 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
  48                                   __func__, ##arg);                     \
  49         } while (0)
  50
  51 static struct snd_pcm_hardware snd_cx18_hw_capture = {
  52         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  53                 SNDRV_PCM_INFO_MMAP           |
  54                 SNDRV_PCM_INFO_INTERLEAVED    |
  55                 SNDRV_PCM_INFO_MMAP_VALID,
  56
  57         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  58
  59         .rates = SNDRV_PCM_RATE_48000,
  60
  61         .rate_min = 48000,
  62         .rate_max = 48000,
  63         .channels_min = 2,
  64         .channels_max = 2,
  65         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  66         .period_bytes_min = 64,         /* 12544/2, */
  67         .period_bytes_max = 12544,
  68         .periods_min = 2,
  69         .periods_max = 98,              /* 12544, */
  70 };
  71
  72 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
  73                                  size_t num_bytes)
  74 {
  75         struct snd_pcm_substream *substream;
  76         struct snd_pcm_runtime *runtime;
  77         unsigned int oldptr;
  78         unsigned int stride;
  79         int period_elapsed = 0;
  80         int length;
  81
  82         dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zd\n", cxsc,
  83                 pcm_data, num_bytes);
  84
  85         substream = cxsc->capture_pcm_substream;
  86         if (substream == NULL) {
  87                 dprintk("substream was NULL\n");
  88                 return;
  89         }
  90
  91         runtime = substream->runtime;
  92         if (runtime == NULL) {
  93                 dprintk("runtime was NULL\n");
  94                 return;
  95         }
  96
  97         stride = runtime->frame_bits >> 3;
  98         if (stride == 0) {
  99                 dprintk("stride is zero\n");
 100                 return;
 101         }
 102
 103         length = num_bytes / stride;
 104         if (length == 0) {
 105                 dprintk("%s: length was zero\n", __func__);
 106                 return;
 107         }
 108
 109         if (runtime->dma_area == NULL) {
 110                 dprintk("dma area was NULL - ignoring\n");
 111                 return;
 112         }
 113
 114         oldptr = cxsc->hwptr_done_capture;
 115         if (oldptr + length >= runtime->buffer_size) {
 116                 unsigned int cnt =
 117                         runtime->buffer_size - oldptr;
 118                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 119                        cnt * stride);
 120                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 121                        length * stride - cnt * stride);
 122         } else {
 123                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 124                        length * stride);
 125         }
 126         snd_pcm_stream_lock(substream);
 127
 128         cxsc->hwptr_done_capture += length;
 129         if (cxsc->hwptr_done_capture >=
 130             runtime->buffer_size)
 131                 cxsc->hwptr_done_capture -=
 132                         runtime->buffer_size;
 133
 134         cxsc->capture_transfer_done += length;
 135         if (cxsc->capture_transfer_done >=
 136             runtime->period_size) {
 137                 cxsc->capture_transfer_done -=
 138                         runtime->period_size;
 139                 period_elapsed = 1;
 140         }
 141
 142         snd_pcm_stream_unlock(substream);
 143
 144         if (period_elapsed)
 145                 snd_pcm_period_elapsed(substream);
 146 }
 147
 148 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
 149 {
 150         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 151         struct snd_pcm_runtime *runtime = substream->runtime;
 152         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 153         struct cx18 *cx = to_cx18(v4l2_dev);
 154         struct cx18_stream *s;
 155         struct cx18_open_id item;
 156         int ret;
 157
 158         /* Instruct the cx18 to start sending packets */
 159         snd_cx18_lock(cxsc);
 160         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 161
 162         item.cx = cx;
 163         item.type = s->type;
 164         item.open_id = cx->open_id++;
 165
 166         /* See if the stream is available */
 167         if (cx18_claim_stream(&item, item.type)) {
 168                 /* No, it's already in use */
 169                 snd_cx18_unlock(cxsc);
 170                 return -EBUSY;
 171         }
 172
 173         if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 174             test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 175                 /* We're already streaming.  No additional action required */
 176                 snd_cx18_unlock(cxsc);
 177                 return 0;
 178         }
 179
 180
 181         runtime->hw = snd_cx18_hw_capture;
 182         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 183         cxsc->capture_pcm_substream = substream;
 184         runtime->private_data = cx;
 185
 186         cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
 187
 188         /* Not currently streaming, so start it up */
 189         set_bit(CX18_F_S_STREAMING, &s->s_flags);
 190         ret = cx18_start_v4l2_encode_stream(s);
 191         snd_cx18_unlock(cxsc);
 192
 193         return 0;
 194 }
 195
 196 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 197 {
 198         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 199         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 200         struct cx18 *cx = to_cx18(v4l2_dev);
 201         struct cx18_stream *s;
 202         int ret;
 203
 204         /* Instruct the cx18 to stop sending packets */
 205         snd_cx18_lock(cxsc);
 206         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 207         ret = cx18_stop_v4l2_encode_stream(s, 0);
 208         clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 209
 210         cx18_release_stream(s);
 211
 212         cx->pcm_announce_callback = NULL;
 213         snd_cx18_unlock(cxsc);
 214
 215         return 0;
 216 }
 217
 218 static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
 219                      unsigned int cmd, void *arg)
 220 {
 221         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 222         int ret;
 223
 224         snd_cx18_lock(cxsc);
 225         ret = snd_pcm_lib_ioctl(substream, cmd, arg);
 226         snd_cx18_unlock(cxsc);
 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_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
 253                          struct snd_pcm_hw_params *params)
 254 {
 255         int ret;
 256
 257         dprintk("%s called\n", __func__);
 258
 259         ret = snd_pcm_alloc_vmalloc_buffer(substream,
 260                                            params_buffer_bytes(params));
 261         return 0;
 262 }
 263
 264 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
 265 {
 266         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 267         unsigned long flags;
 268
 269         spin_lock_irqsave(&cxsc->slock, flags);
 270         if (substream->runtime->dma_area) {
 271                 dprintk("freeing pcm capture region\n");
 272                 vfree(substream->runtime->dma_area);
 273                 substream->runtime->dma_area = NULL;
 274         }
 275         spin_unlock_irqrestore(&cxsc->slock, flags);
 276
 277         return 0;
 278 }
 279
 280 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
 281 {
 282         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 283
 284         cxsc->hwptr_done_capture = 0;
 285         cxsc->capture_transfer_done = 0;
 286
 287         return 0;
 288 }
 289
 290 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 291 {
 292         return 0;
 293 }
 294
 295 static
 296 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 297 {
 298         unsigned long flags;
 299         snd_pcm_uframes_t hwptr_done;
 300         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 301
 302         spin_lock_irqsave(&cxsc->slock, flags);
 303         hwptr_done = cxsc->hwptr_done_capture;
 304         spin_unlock_irqrestore(&cxsc->slock, flags);
 305
 306         return hwptr_done;
 307 }
 308
 309 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 310                                              unsigned long offset)
 311 {
 312         void *pageptr = subs->runtime->dma_area + offset;
 313
 314         return vmalloc_to_page(pageptr);
 315 }
 316
 317 static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
 318         .open           = snd_cx18_pcm_capture_open,
 319         .close          = snd_cx18_pcm_capture_close,
 320         .ioctl          = snd_cx18_pcm_ioctl,
 321         .hw_params      = snd_cx18_pcm_hw_params,
 322         .hw_free        = snd_cx18_pcm_hw_free,
 323         .prepare        = snd_cx18_pcm_prepare,
 324         .trigger        = snd_cx18_pcm_trigger,
 325         .pointer        = snd_cx18_pcm_pointer,
 326         .page           = snd_pcm_get_vmalloc_page,
 327 };
 328
 329 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 330 {
 331         struct snd_pcm *sp;
 332         struct snd_card *sc = cxsc->sc;
 333         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 334         struct cx18 *cx = to_cx18(v4l2_dev);
 335         int ret;
 336
 337         ret = snd_pcm_new(sc, "CX23418 PCM",
 338                           0, /* PCM device 0, the only one for this card */
 339                           0, /* 0 playback substreams */
 340                           1, /* 1 capture substream */
 341                           &sp);
 342         if (ret) {
 343                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 344                               __func__, ret);
 345                 goto err_exit;
 346         }
 347
 348         spin_lock_init(&cxsc->slock);
 349
 350         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 351                         &snd_cx18_pcm_capture_ops);
 352         sp->info_flags = 0;
 353         sp->private_data = cxsc;
 354         strlcpy(sp->name, cx->card_name, sizeof(sp->name));
 355
 356         return 0;
 357
 358 err_exit:
 359         return ret;
 360 }