drivers/media/pci/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 #include "cx18-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...) do {                                       \
  47             if (pcm_debug)                                              \
  48                 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
  49                                   __func__, ##arg);                     \
  50         } while (0)
  51
  52 static struct snd_pcm_hardware snd_cx18_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 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
  74                                  size_t num_bytes)
  75 {
  76         struct snd_pcm_substream *substream;
  77         struct snd_pcm_runtime *runtime;
  78         unsigned int oldptr;
  79         unsigned int stride;
  80         int period_elapsed = 0;
  81         int length;
  82
  83         dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
  84                 pcm_data, num_bytes);
  85
  86         substream = cxsc->capture_pcm_substream;
  87         if (substream == NULL) {
  88                 dprintk("substream was NULL\n");
  89                 return;
  90         }
  91
  92         runtime = substream->runtime;
  93         if (runtime == NULL) {
  94                 dprintk("runtime was NULL\n");
  95                 return;
  96         }
  97
  98         stride = runtime->frame_bits >> 3;
  99         if (stride == 0) {
 100                 dprintk("stride is zero\n");
 101                 return;
 102         }
 103
 104         length = num_bytes / stride;
 105         if (length == 0) {
 106                 dprintk("%s: length was zero\n", __func__);
 107                 return;
 108         }
 109
 110         if (runtime->dma_area == NULL) {
 111                 dprintk("dma area was NULL - ignoring\n");
 112                 return;
 113         }
 114
 115         oldptr = cxsc->hwptr_done_capture;
 116         if (oldptr + length >= runtime->buffer_size) {
 117                 unsigned int cnt =
 118                         runtime->buffer_size - oldptr;
 119                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 120                        cnt * stride);
 121                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 122                        length * stride - cnt * stride);
 123         } else {
 124                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 125                        length * stride);
 126         }
 127         snd_pcm_stream_lock(substream);
 128
 129         cxsc->hwptr_done_capture += length;
 130         if (cxsc->hwptr_done_capture >=
 131             runtime->buffer_size)
 132                 cxsc->hwptr_done_capture -=
 133                         runtime->buffer_size;
 134
 135         cxsc->capture_transfer_done += length;
 136         if (cxsc->capture_transfer_done >=
 137             runtime->period_size) {
 138                 cxsc->capture_transfer_done -=
 139                         runtime->period_size;
 140                 period_elapsed = 1;
 141         }
 142
 143         snd_pcm_stream_unlock(substream);
 144
 145         if (period_elapsed)
 146                 snd_pcm_period_elapsed(substream);
 147 }
 148
 149 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
 150 {
 151         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 152         struct snd_pcm_runtime *runtime = substream->runtime;
 153         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 154         struct cx18 *cx = to_cx18(v4l2_dev);
 155         struct cx18_stream *s;
 156         struct cx18_open_id item;
 157         int ret;
 158
 159         /* Instruct the cx18 to start sending packets */
 160         snd_cx18_lock(cxsc);
 161         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 162
 163         item.cx = cx;
 164         item.type = s->type;
 165         item.open_id = cx->open_id++;
 166
 167         /* See if the stream is available */
 168         if (cx18_claim_stream(&item, item.type)) {
 169                 /* No, it's already in use */
 170                 snd_cx18_unlock(cxsc);
 171                 return -EBUSY;
 172         }
 173
 174         if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 175             test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 176                 /* We're already streaming.  No additional action required */
 177                 snd_cx18_unlock(cxsc);
 178                 return 0;
 179         }
 180
 181
 182         runtime->hw = snd_cx18_hw_capture;
 183         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 184         cxsc->capture_pcm_substream = substream;
 185         runtime->private_data = cx;
 186
 187         cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
 188
 189         /* Not currently streaming, so start it up */
 190         set_bit(CX18_F_S_STREAMING, &s->s_flags);
 191         ret = cx18_start_v4l2_encode_stream(s);
 192         snd_cx18_unlock(cxsc);
 193
 194         return ret;
 195 }
 196
 197 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 198 {
 199         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 200         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 201         struct cx18 *cx = to_cx18(v4l2_dev);
 202         struct cx18_stream *s;
 203
 204         /* Instruct the cx18 to stop sending packets */
 205         snd_cx18_lock(cxsc);
 206         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 207         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         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_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
 262 {
 263         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 264         unsigned long flags;
 265
 266         spin_lock_irqsave(&cxsc->slock, flags);
 267         if (substream->runtime->dma_area) {
 268                 dprintk("freeing pcm capture region\n");
 269                 vfree(substream->runtime->dma_area);
 270                 substream->runtime->dma_area = NULL;
 271         }
 272         spin_unlock_irqrestore(&cxsc->slock, flags);
 273
 274         return 0;
 275 }
 276
 277 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
 278 {
 279         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 280
 281         cxsc->hwptr_done_capture = 0;
 282         cxsc->capture_transfer_done = 0;
 283
 284         return 0;
 285 }
 286
 287 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 288 {
 289         return 0;
 290 }
 291
 292 static
 293 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 294 {
 295         unsigned long flags;
 296         snd_pcm_uframes_t hwptr_done;
 297         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 298
 299         spin_lock_irqsave(&cxsc->slock, flags);
 300         hwptr_done = cxsc->hwptr_done_capture;
 301         spin_unlock_irqrestore(&cxsc->slock, flags);
 302
 303         return hwptr_done;
 304 }
 305
 306 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 307                                              unsigned long offset)
 308 {
 309         void *pageptr = subs->runtime->dma_area + offset;
 310
 311         return vmalloc_to_page(pageptr);
 312 }
 313
 314 static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
 315         .open           = snd_cx18_pcm_capture_open,
 316         .close          = snd_cx18_pcm_capture_close,
 317         .ioctl          = snd_cx18_pcm_ioctl,
 318         .hw_params      = snd_cx18_pcm_hw_params,
 319         .hw_free        = snd_cx18_pcm_hw_free,
 320         .prepare        = snd_cx18_pcm_prepare,
 321         .trigger        = snd_cx18_pcm_trigger,
 322         .pointer        = snd_cx18_pcm_pointer,
 323         .page           = snd_pcm_get_vmalloc_page,
 324 };
 325
 326 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 327 {
 328         struct snd_pcm *sp;
 329         struct snd_card *sc = cxsc->sc;
 330         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 331         struct cx18 *cx = to_cx18(v4l2_dev);
 332         int ret;
 333
 334         ret = snd_pcm_new(sc, "CX23418 PCM",
 335                           0, /* PCM device 0, the only one for this card */
 336                           0, /* 0 playback substreams */
 337                           1, /* 1 capture substream */
 338                           &sp);
 339         if (ret) {
 340                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 341                               __func__, ret);
 342                 goto err_exit;
 343         }
 344
 345         spin_lock_init(&cxsc->slock);
 346
 347         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 348                         &snd_cx18_pcm_capture_ops);
 349         sp->info_flags = 0;
 350         sp->private_data = cxsc;
 351         strlcpy(sp->name, cx->card_name, sizeof(sp->name));
 352
 353         return 0;
 354
 355 err_exit:
 356         return ret;
 357 }