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@radix.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
  29 #include <media/v4l2-device.h>
  30
  31 #include <sound/core.h>
  32 #include <sound/pcm.h>
  33
  34 #include "cx18-driver.h"
  35 #include "cx18-queue.h"
  36 #include "cx18-streams.h"
  37 #include "cx18-fileops.h"
  38 #include "cx18-alsa.h"
  39
  40 static unsigned int pcm_debug;
  41 module_param(pcm_debug, int, 0644);
  42 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  43
  44 #define dprintk(fmt, arg...) do {                                       \
  45             if (pcm_debug)                                              \
  46                 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
  47                                   __func__, ##arg);                     \
  48         } while (0)
  49
  50 /* Forward Declaration */
  51 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
  52                                  size_t num_bytes);
  53
  54 static struct snd_pcm_hardware snd_cx18_hw_capture = {
  55         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  56                 SNDRV_PCM_INFO_MMAP           |
  57                 SNDRV_PCM_INFO_INTERLEAVED    |
  58                 SNDRV_PCM_INFO_MMAP_VALID,
  59
  60         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  61
  62         .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
  63
  64         .rate_min = 48000,
  65         .rate_max = 48000,
  66         .channels_min = 2,
  67         .channels_max = 2,
  68         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  69         .period_bytes_min = 64,         /* 12544/2, */
  70         .period_bytes_max = 12544,
  71         .periods_min = 2,
  72         .periods_max = 98,              /* 12544, */
  73 };
  74
  75 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
  76 {
  77         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
  78         struct snd_pcm_runtime *runtime = substream->runtime;
  79         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
  80         struct cx18 *cx = to_cx18(v4l2_dev);
  81         struct cx18_stream *s;
  82         struct cx18_open_id *item;
  83         int ret;
  84
  85         /* Instruct the cx18 to start sending packets */
  86         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
  87
  88         /* Allocate memory */
  89         item = kmalloc(sizeof(struct cx18_open_id), GFP_KERNEL);
  90         if (NULL == item)
  91                 return -ENOMEM;
  92
  93         item->cx = cx;
  94         item->type = s->type;
  95         item->open_id = cx->open_id++;
  96
  97         /* See if the stream is available */
  98         if (cx18_claim_stream(item, item->type)) {
  99                 /* No, it's already in use */
 100                 kfree(item);
 101                 return -EBUSY;
 102         }
 103
 104         if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 105             test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 106                 /* We're already streaming.  No additional action required */
 107                 return 0;
 108         }
 109
 110
 111         runtime->hw = snd_cx18_hw_capture;
 112         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 113         cxsc->capture_pcm_substream = substream;
 114         runtime->private_data = cx;
 115
 116         cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
 117
 118         /* Not currently streaming, so start it up */
 119         set_bit(CX18_F_S_STREAMING, &s->s_flags);
 120         ret = cx18_start_v4l2_encode_stream(s);
 121
 122         return 0;
 123 }
 124
 125 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 126 {
 127         unsigned long flags;
 128         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 129         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 130         struct cx18 *cx = to_cx18(v4l2_dev);
 131         struct cx18_stream *s;
 132         int ret;
 133
 134         /* Instruct the cx18 to stop sending packets */
 135         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 136         ret = cx18_stop_v4l2_encode_stream(s, 0);
 137         clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 138
 139         cx18_release_stream(s);
 140
 141         cx->pcm_announce_callback = NULL;
 142
 143         spin_lock_irqsave(&cxsc->slock, flags);
 144         if (substream->runtime->dma_area) {
 145                 dprintk("freeing pcm capture region\n");
 146                 vfree(substream->runtime->dma_area);
 147                 substream->runtime->dma_area = NULL;
 148         }
 149         spin_unlock_irqrestore(&cxsc->slock, flags);
 150
 151         return 0;
 152 }
 153
 154 static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
 155                      unsigned int cmd, void *arg)
 156 {
 157         return snd_pcm_lib_ioctl(substream, cmd, arg);
 158 }
 159
 160
 161 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
 162                                         size_t size)
 163 {
 164         struct snd_pcm_runtime *runtime = subs->runtime;
 165
 166         dprintk("Allocating vbuffer\n");
 167         if (runtime->dma_area) {
 168                 if (runtime->dma_bytes > size)
 169                         return 0;
 170
 171                 vfree(runtime->dma_area);
 172         }
 173         runtime->dma_area = vmalloc(size);
 174         if (!runtime->dma_area)
 175                 return -ENOMEM;
 176
 177         runtime->dma_bytes = size;
 178
 179         return 0;
 180 }
 181
 182 static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
 183                          struct snd_pcm_hw_params *params)
 184 {
 185         int ret;
 186
 187         dprintk("%s called\n", __func__);
 188
 189         ret = snd_pcm_alloc_vmalloc_buffer(substream,
 190                                            params_buffer_bytes(params));
 191         return 0;
 192 }
 193
 194 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
 195 {
 196         return 0;
 197 }
 198
 199 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
 200 {
 201         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 202
 203         cxsc->hwptr_done_capture = 0;
 204         cxsc->capture_transfer_done = 0;
 205
 206         return 0;
 207 }
 208
 209 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 210 {
 211         return 0;
 212 }
 213
 214 static
 215 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 216 {
 217         unsigned long flags;
 218         snd_pcm_uframes_t hwptr_done;
 219         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 220
 221         spin_lock_irqsave(&cxsc->slock, flags);
 222         hwptr_done = cxsc->hwptr_done_capture;
 223         spin_unlock_irqrestore(&cxsc->slock, flags);
 224
 225         return hwptr_done;
 226 }
 227
 228 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 229                                              unsigned long offset)
 230 {
 231         void *pageptr = subs->runtime->dma_area + offset;
 232
 233         return vmalloc_to_page(pageptr);
 234 }
 235
 236 static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
 237         .open           = snd_cx18_pcm_capture_open,
 238         .close          = snd_cx18_pcm_capture_close,
 239         .ioctl          = snd_cx18_pcm_ioctl,
 240         .hw_params      = snd_cx18_pcm_hw_params,
 241         .hw_free        = snd_cx18_pcm_hw_free,
 242         .prepare        = snd_cx18_pcm_prepare,
 243         .trigger        = snd_cx18_pcm_trigger,
 244         .pointer        = snd_cx18_pcm_pointer,
 245         .page           = snd_pcm_get_vmalloc_page,
 246 };
 247
 248 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
 249                                  size_t num_bytes)
 250 {
 251         struct snd_pcm_substream *substream;
 252         struct snd_pcm_runtime *runtime;
 253         unsigned int oldptr;
 254         unsigned int stride;
 255         int period_elapsed = 0;
 256         int length;
 257
 258         dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%d\n", cxsc,
 259                 pcm_data, num_bytes);
 260
 261         substream = cxsc->capture_pcm_substream;
 262         if (substream == NULL) {
 263                 dprintk("substream was NULL\n");
 264                 return;
 265         }
 266
 267         runtime = substream->runtime;
 268         if (runtime == NULL) {
 269                 dprintk("runtime was NULL\n");
 270                 return;
 271         }
 272
 273         stride = runtime->frame_bits >> 3;
 274         if (stride == 0) {
 275                 dprintk("stride is zero\n");
 276                 return;
 277         }
 278
 279         length = num_bytes / stride;
 280         if (length == 0) {
 281                 dprintk("%s: length was zero\n", __func__);
 282                 return;
 283         }
 284
 285         if (runtime->dma_area == NULL) {
 286                 dprintk("dma area was NULL - ignoring\n");
 287                 return;
 288         }
 289
 290         oldptr = cxsc->hwptr_done_capture;
 291         if (oldptr + length >= runtime->buffer_size) {
 292                 unsigned int cnt =
 293                         runtime->buffer_size - oldptr;
 294                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 295                        cnt * stride);
 296                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 297                        length * stride - cnt * stride);
 298         } else {
 299                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 300                        length * stride);
 301         }
 302         snd_pcm_stream_lock(substream);
 303
 304         cxsc->hwptr_done_capture += length;
 305         if (cxsc->hwptr_done_capture >=
 306             runtime->buffer_size)
 307                 cxsc->hwptr_done_capture -=
 308                         runtime->buffer_size;
 309
 310         cxsc->capture_transfer_done += length;
 311         if (cxsc->capture_transfer_done >=
 312             runtime->period_size) {
 313                 cxsc->capture_transfer_done -=
 314                         runtime->period_size;
 315                 period_elapsed = 1;
 316         }
 317
 318         snd_pcm_stream_unlock(substream);
 319
 320         if (period_elapsed)
 321                 snd_pcm_period_elapsed(substream);
 322 }
 323
 324 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 325 {
 326         struct snd_pcm *sp;
 327         struct snd_card *sc = cxsc->sc;
 328         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 329         struct cx18 *cx = to_cx18(v4l2_dev);
 330         int ret;
 331
 332         ret = snd_pcm_new(sc, "CX23418 PCM",
 333                           0, /* PCM device 0, the only one for this card */
 334                           0, /* 0 playback substreams */
 335                           1, /* 1 capture substream */
 336                           &sp);
 337         if (ret) {
 338                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 339                               __func__, ret);
 340                 goto err_exit;
 341         }
 342
 343         spin_lock_init(&cxsc->slock);
 344
 345         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 346                         &snd_cx18_pcm_capture_ops);
 347         sp->info_flags = 0;
 348         sp->private_data = cxsc;
 349         strlcpy(sp->name, cx->card_name, sizeof(sp->name));
 350
 351         return 0;
 352
 353 err_exit:
 354         return ret;
 355 }