drivers/media/pci/ivtv/ivtv-alsa-pcm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ALSA PCM device for the
   4  *  ALSA interface to ivtv PCM capture streams
   5  *
   6  *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
   7  *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
   8  *
   9  *  Portions of this work were sponsored by ONELAN Limited for the cx18 driver
  10  */
  11
  12 #include "ivtv-driver.h"
  13 #include "ivtv-queue.h"
  14 #include "ivtv-streams.h"
  15 #include "ivtv-fileops.h"
  16 #include "ivtv-alsa.h"
  17 #include "ivtv-alsa-pcm.h"
  18
  19 #include <sound/core.h>
  20 #include <sound/pcm.h>
  21
  22
  23 static unsigned int pcm_debug;
  24 module_param(pcm_debug, int, 0644);
  25 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  26
  27 #define dprintk(fmt, arg...) \
  28         do { \
  29                 if (pcm_debug) \
  30                         pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
  31         } while (0)
  32
  33 static const struct snd_pcm_hardware snd_ivtv_hw_capture = {
  34         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  35                 SNDRV_PCM_INFO_MMAP           |
  36                 SNDRV_PCM_INFO_INTERLEAVED    |
  37                 SNDRV_PCM_INFO_MMAP_VALID,
  38
  39         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  40
  41         .rates = SNDRV_PCM_RATE_48000,
  42
  43         .rate_min = 48000,
  44         .rate_max = 48000,
  45         .channels_min = 2,
  46         .channels_max = 2,
  47         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  48         .period_bytes_min = 64,         /* 12544/2, */
  49         .period_bytes_max = 12544,
  50         .periods_min = 2,
  51         .periods_max = 98,              /* 12544, */
  52 };
  53
  54 static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
  55                                         u8 *pcm_data,
  56                                         size_t num_bytes)
  57 {
  58         struct snd_pcm_substream *substream;
  59         struct snd_pcm_runtime *runtime;
  60         unsigned int oldptr;
  61         unsigned int stride;
  62         int period_elapsed = 0;
  63         int length;
  64
  65         dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
  66                 pcm_data, num_bytes);
  67
  68         substream = itvsc->capture_pcm_substream;
  69         if (substream == NULL) {
  70                 dprintk("substream was NULL\n");
  71                 return;
  72         }
  73
  74         runtime = substream->runtime;
  75         if (runtime == NULL) {
  76                 dprintk("runtime was NULL\n");
  77                 return;
  78         }
  79
  80         stride = runtime->frame_bits >> 3;
  81         if (stride == 0) {
  82                 dprintk("stride is zero\n");
  83                 return;
  84         }
  85
  86         length = num_bytes / stride;
  87         if (length == 0) {
  88                 dprintk("%s: length was zero\n", __func__);
  89                 return;
  90         }
  91
  92         if (runtime->dma_area == NULL) {
  93                 dprintk("dma area was NULL - ignoring\n");
  94                 return;
  95         }
  96
  97         oldptr = itvsc->hwptr_done_capture;
  98         if (oldptr + length >= runtime->buffer_size) {
  99                 unsigned int cnt =
 100                         runtime->buffer_size - oldptr;
 101                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 102                        cnt * stride);
 103                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 104                        length * stride - cnt * stride);
 105         } else {
 106                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 107                        length * stride);
 108         }
 109         snd_pcm_stream_lock(substream);
 110
 111         itvsc->hwptr_done_capture += length;
 112         if (itvsc->hwptr_done_capture >=
 113             runtime->buffer_size)
 114                 itvsc->hwptr_done_capture -=
 115                         runtime->buffer_size;
 116
 117         itvsc->capture_transfer_done += length;
 118         if (itvsc->capture_transfer_done >=
 119             runtime->period_size) {
 120                 itvsc->capture_transfer_done -=
 121                         runtime->period_size;
 122                 period_elapsed = 1;
 123         }
 124
 125         snd_pcm_stream_unlock(substream);
 126
 127         if (period_elapsed)
 128                 snd_pcm_period_elapsed(substream);
 129 }
 130
 131 static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
 132 {
 133         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 134         struct snd_pcm_runtime *runtime = substream->runtime;
 135         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 136         struct ivtv *itv = to_ivtv(v4l2_dev);
 137         struct ivtv_stream *s;
 138         struct ivtv_open_id item;
 139         int ret;
 140
 141         /* Instruct the CX2341[56] to start sending packets */
 142         snd_ivtv_lock(itvsc);
 143
 144         if (ivtv_init_on_first_open(itv)) {
 145                 snd_ivtv_unlock(itvsc);
 146                 return -ENXIO;
 147         }
 148
 149         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 150
 151         v4l2_fh_init(&item.fh, &s->vdev);
 152         item.itv = itv;
 153         item.type = s->type;
 154
 155         /* See if the stream is available */
 156         if (ivtv_claim_stream(&item, item.type)) {
 157                 /* No, it's already in use */
 158                 v4l2_fh_exit(&item.fh);
 159                 snd_ivtv_unlock(itvsc);
 160                 return -EBUSY;
 161         }
 162
 163         if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
 164             test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
 165                 /* We're already streaming.  No additional action required */
 166                 snd_ivtv_unlock(itvsc);
 167                 return 0;
 168         }
 169
 170
 171         runtime->hw = snd_ivtv_hw_capture;
 172         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 173         itvsc->capture_pcm_substream = substream;
 174         runtime->private_data = itv;
 175
 176         itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
 177
 178         /* Not currently streaming, so start it up */
 179         set_bit(IVTV_F_S_STREAMING, &s->s_flags);
 180         ret = ivtv_start_v4l2_encode_stream(s);
 181         snd_ivtv_unlock(itvsc);
 182
 183         return ret;
 184 }
 185
 186 static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
 187 {
 188         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 189         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 190         struct ivtv *itv = to_ivtv(v4l2_dev);
 191         struct ivtv_stream *s;
 192
 193         /* Instruct the ivtv to stop sending packets */
 194         snd_ivtv_lock(itvsc);
 195         s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 196         ivtv_stop_v4l2_encode_stream(s, 0);
 197         clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
 198
 199         ivtv_release_stream(s);
 200
 201         itv->pcm_announce_callback = NULL;
 202         snd_ivtv_unlock(itvsc);
 203
 204         return 0;
 205 }
 206
 207 static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
 208 {
 209         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 210
 211         itvsc->hwptr_done_capture = 0;
 212         itvsc->capture_transfer_done = 0;
 213
 214         return 0;
 215 }
 216
 217 static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 218 {
 219         return 0;
 220 }
 221
 222 static
 223 snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
 224 {
 225         unsigned long flags;
 226         snd_pcm_uframes_t hwptr_done;
 227         struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 228
 229         spin_lock_irqsave(&itvsc->slock, flags);
 230         hwptr_done = itvsc->hwptr_done_capture;
 231         spin_unlock_irqrestore(&itvsc->slock, flags);
 232
 233         return hwptr_done;
 234 }
 235
 236 static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
 237         .open           = snd_ivtv_pcm_capture_open,
 238         .close          = snd_ivtv_pcm_capture_close,
 239         .prepare        = snd_ivtv_pcm_prepare,
 240         .trigger        = snd_ivtv_pcm_trigger,
 241         .pointer        = snd_ivtv_pcm_pointer,
 242 };
 243
 244 int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
 245 {
 246         struct snd_pcm *sp;
 247         struct snd_card *sc = itvsc->sc;
 248         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 249         struct ivtv *itv = to_ivtv(v4l2_dev);
 250         int ret;
 251
 252         ret = snd_pcm_new(sc, "CX2341[56] PCM",
 253                           0, /* PCM device 0, the only one for this card */
 254                           0, /* 0 playback substreams */
 255                           1, /* 1 capture substream */
 256                           &sp);
 257         if (ret) {
 258                 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
 259                               __func__, ret);
 260                 goto err_exit;
 261         }
 262
 263         spin_lock_init(&itvsc->slock);
 264
 265         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 266                         &snd_ivtv_pcm_capture_ops);
 267         snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
 268         sp->info_flags = 0;
 269         sp->private_data = itvsc;
 270         strscpy(sp->name, itv->card_name, sizeof(sp->name));
 271
 272         return 0;
 273
 274 err_exit:
 275         return ret;
 276 }