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
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/vmalloc.h>
  24
  25 #include <media/v4l2-device.h>
  26
  27 #include <sound/core.h>
  28 #include <sound/pcm.h>
  29
  30 #include "cx18-driver.h"
  31 #include "cx18-queue.h"
  32 #include "cx18-streams.h"
  33 #include "cx18-fileops.h"
  34 #include "cx18-alsa.h"
  35 #include "cx18-alsa-pcm.h"
  36
  37 static unsigned int pcm_debug;
  38 module_param(pcm_debug, int, 0644);
  39 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  40
  41 #define dprintk(fmt, arg...) do {                                       \
  42             if (pcm_debug)                                              \
  43                 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
  44                                   __func__, ##arg);                     \
  45         } while (0)
  46
  47 static const struct snd_pcm_hardware snd_cx18_hw_capture = {
  48         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  49                 SNDRV_PCM_INFO_MMAP           |
  50                 SNDRV_PCM_INFO_INTERLEAVED    |
  51                 SNDRV_PCM_INFO_MMAP_VALID,
  52
  53         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  54
  55         .rates = SNDRV_PCM_RATE_48000,
  56
  57         .rate_min = 48000,
  58         .rate_max = 48000,
  59         .channels_min = 2,
  60         .channels_max = 2,
  61         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  62         .period_bytes_min = 64,         /* 12544/2, */
  63         .period_bytes_max = 12544,
  64         .periods_min = 2,
  65         .periods_max = 98,              /* 12544, */
  66 };
  67
  68 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
  69                                  size_t num_bytes)
  70 {
  71         struct snd_pcm_substream *substream;
  72         struct snd_pcm_runtime *runtime;
  73         unsigned int oldptr;
  74         unsigned int stride;
  75         int period_elapsed = 0;
  76         int length;
  77
  78         dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
  79                 pcm_data, num_bytes);
  80
  81         substream = cxsc->capture_pcm_substream;
  82         if (substream == NULL) {
  83                 dprintk("substream was NULL\n");
  84                 return;
  85         }
  86
  87         runtime = substream->runtime;
  88         if (runtime == NULL) {
  89                 dprintk("runtime was NULL\n");
  90                 return;
  91         }
  92
  93         stride = runtime->frame_bits >> 3;
  94         if (stride == 0) {
  95                 dprintk("stride is zero\n");
  96                 return;
  97         }
  98
  99         length = num_bytes / stride;
 100         if (length == 0) {
 101                 dprintk("%s: length was zero\n", __func__);
 102                 return;
 103         }
 104
 105         if (runtime->dma_area == NULL) {
 106                 dprintk("dma area was NULL - ignoring\n");
 107                 return;
 108         }
 109
 110         oldptr = cxsc->hwptr_done_capture;
 111         if (oldptr + length >= runtime->buffer_size) {
 112                 unsigned int cnt =
 113                         runtime->buffer_size - oldptr;
 114                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 115                        cnt * stride);
 116                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 117                        length * stride - cnt * stride);
 118         } else {
 119                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 120                        length * stride);
 121         }
 122         snd_pcm_stream_lock(substream);
 123
 124         cxsc->hwptr_done_capture += length;
 125         if (cxsc->hwptr_done_capture >=
 126             runtime->buffer_size)
 127                 cxsc->hwptr_done_capture -=
 128                         runtime->buffer_size;
 129
 130         cxsc->capture_transfer_done += length;
 131         if (cxsc->capture_transfer_done >=
 132             runtime->period_size) {
 133                 cxsc->capture_transfer_done -=
 134                         runtime->period_size;
 135                 period_elapsed = 1;
 136         }
 137
 138         snd_pcm_stream_unlock(substream);
 139
 140         if (period_elapsed)
 141                 snd_pcm_period_elapsed(substream);
 142 }
 143
 144 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
 145 {
 146         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 147         struct snd_pcm_runtime *runtime = substream->runtime;
 148         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 149         struct cx18 *cx = to_cx18(v4l2_dev);
 150         struct cx18_stream *s;
 151         struct cx18_open_id item;
 152         int ret;
 153
 154         /* Instruct the cx18 to start sending packets */
 155         snd_cx18_lock(cxsc);
 156         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 157
 158         item.cx = cx;
 159         item.type = s->type;
 160         item.open_id = cx->open_id++;
 161
 162         /* See if the stream is available */
 163         if (cx18_claim_stream(&item, item.type)) {
 164                 /* No, it's already in use */
 165                 snd_cx18_unlock(cxsc);
 166                 return -EBUSY;
 167         }
 168
 169         if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 170             test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 171                 /* We're already streaming.  No additional action required */
 172                 snd_cx18_unlock(cxsc);
 173                 return 0;
 174         }
 175
 176
 177         runtime->hw = snd_cx18_hw_capture;
 178         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 179         cxsc->capture_pcm_substream = substream;
 180         runtime->private_data = cx;
 181
 182         cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
 183
 184         /* Not currently streaming, so start it up */
 185         set_bit(CX18_F_S_STREAMING, &s->s_flags);
 186         ret = cx18_start_v4l2_encode_stream(s);
 187         snd_cx18_unlock(cxsc);
 188
 189         return ret;
 190 }
 191
 192 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 193 {
 194         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 195         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 196         struct cx18 *cx = to_cx18(v4l2_dev);
 197         struct cx18_stream *s;
 198
 199         /* Instruct the cx18 to stop sending packets */
 200         snd_cx18_lock(cxsc);
 201         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 202         cx18_stop_v4l2_encode_stream(s, 0);
 203         clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 204
 205         cx18_release_stream(s);
 206
 207         cx->pcm_announce_callback = NULL;
 208         snd_cx18_unlock(cxsc);
 209
 210         return 0;
 211 }
 212
 213 static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
 214                      unsigned int cmd, void *arg)
 215 {
 216         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 217         int ret;
 218
 219         snd_cx18_lock(cxsc);
 220         ret = snd_pcm_lib_ioctl(substream, cmd, arg);
 221         snd_cx18_unlock(cxsc);
 222         return ret;
 223 }
 224
 225
 226 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
 227                                         size_t size)
 228 {
 229         struct snd_pcm_runtime *runtime = subs->runtime;
 230
 231         dprintk("Allocating vbuffer\n");
 232         if (runtime->dma_area) {
 233                 if (runtime->dma_bytes > size)
 234                         return 0;
 235
 236                 vfree(runtime->dma_area);
 237         }
 238         runtime->dma_area = vmalloc(size);
 239         if (!runtime->dma_area)
 240                 return -ENOMEM;
 241
 242         runtime->dma_bytes = size;
 243
 244         return 0;
 245 }
 246
 247 static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
 248                          struct snd_pcm_hw_params *params)
 249 {
 250         dprintk("%s called\n", __func__);
 251
 252         return snd_pcm_alloc_vmalloc_buffer(substream,
 253                                            params_buffer_bytes(params));
 254 }
 255
 256 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
 257 {
 258         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 259         unsigned long flags;
 260         unsigned char *dma_area = NULL;
 261
 262         spin_lock_irqsave(&cxsc->slock, flags);
 263         if (substream->runtime->dma_area) {
 264                 dprintk("freeing pcm capture region\n");
 265                 dma_area = substream->runtime->dma_area;
 266                 substream->runtime->dma_area = NULL;
 267         }
 268         spin_unlock_irqrestore(&cxsc->slock, flags);
 269         vfree(dma_area);
 270
 271         return 0;
 272 }
 273
 274 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
 275 {
 276         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 277
 278         cxsc->hwptr_done_capture = 0;
 279         cxsc->capture_transfer_done = 0;
 280
 281         return 0;
 282 }
 283
 284 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 285 {
 286         return 0;
 287 }
 288
 289 static
 290 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 291 {
 292         unsigned long flags;
 293         snd_pcm_uframes_t hwptr_done;
 294         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 295
 296         spin_lock_irqsave(&cxsc->slock, flags);
 297         hwptr_done = cxsc->hwptr_done_capture;
 298         spin_unlock_irqrestore(&cxsc->slock, flags);
 299
 300         return hwptr_done;
 301 }
 302
 303 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 304                                              unsigned long offset)
 305 {
 306         void *pageptr = subs->runtime->dma_area + offset;
 307
 308         return vmalloc_to_page(pageptr);
 309 }
 310
 311 static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
 312         .open           = snd_cx18_pcm_capture_open,
 313         .close          = snd_cx18_pcm_capture_close,
 314         .ioctl          = snd_cx18_pcm_ioctl,
 315         .hw_params      = snd_cx18_pcm_hw_params,
 316         .hw_free        = snd_cx18_pcm_hw_free,
 317         .prepare        = snd_cx18_pcm_prepare,
 318         .trigger        = snd_cx18_pcm_trigger,
 319         .pointer        = snd_cx18_pcm_pointer,
 320         .page           = snd_pcm_get_vmalloc_page,
 321 };
 322
 323 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 324 {
 325         struct snd_pcm *sp;
 326         struct snd_card *sc = cxsc->sc;
 327         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 328         struct cx18 *cx = to_cx18(v4l2_dev);
 329         int ret;
 330
 331         ret = snd_pcm_new(sc, "CX23418 PCM",
 332                           0, /* PCM device 0, the only one for this card */
 333                           0, /* 0 playback substreams */
 334                           1, /* 1 capture substream */
 335                           &sp);
 336         if (ret) {
 337                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 338                               __func__, ret);
 339                 goto err_exit;
 340         }
 341
 342         spin_lock_init(&cxsc->slock);
 343
 344         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 345                         &snd_cx18_pcm_capture_ops);
 346         sp->info_flags = 0;
 347         sp->private_data = cxsc;
 348         strlcpy(sp->name, cx->card_name, sizeof(sp->name));
 349
 350         return 0;
 351
 352 err_exit:
 353         return ret;
 354 }