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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ALSA PCM device for the
   4  *  ALSA interface to cx18 PCM capture streams
   5  *
   6  *  Copyright (C) 2009  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.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14
  15 #include <media/v4l2-device.h>
  16
  17 #include <sound/core.h>
  18 #include <sound/pcm.h>
  19
  20 #include "cx18-driver.h"
  21 #include "cx18-queue.h"
  22 #include "cx18-streams.h"
  23 #include "cx18-fileops.h"
  24 #include "cx18-alsa.h"
  25 #include "cx18-alsa-pcm.h"
  26
  27 static unsigned int pcm_debug;
  28 module_param(pcm_debug, int, 0644);
  29 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  30
  31 #define dprintk(fmt, arg...) do {                                       \
  32             if (pcm_debug)                                              \
  33                 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,              \
  34                                   __func__, ##arg);                     \
  35         } while (0)
  36
  37 static const struct snd_pcm_hardware snd_cx18_hw_capture = {
  38         .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  39                 SNDRV_PCM_INFO_MMAP           |
  40                 SNDRV_PCM_INFO_INTERLEAVED    |
  41                 SNDRV_PCM_INFO_MMAP_VALID,
  42
  43         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  44
  45         .rates = SNDRV_PCM_RATE_48000,
  46
  47         .rate_min = 48000,
  48         .rate_max = 48000,
  49         .channels_min = 2,
  50         .channels_max = 2,
  51         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  52         .period_bytes_min = 64,         /* 12544/2, */
  53         .period_bytes_max = 12544,
  54         .periods_min = 2,
  55         .periods_max = 98,              /* 12544, */
  56 };
  57
  58 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
  59                                  size_t num_bytes)
  60 {
  61         struct snd_pcm_substream *substream;
  62         struct snd_pcm_runtime *runtime;
  63         unsigned int oldptr;
  64         unsigned int stride;
  65         int period_elapsed = 0;
  66         int length;
  67
  68         dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
  69                 pcm_data, num_bytes);
  70
  71         substream = cxsc->capture_pcm_substream;
  72         if (substream == NULL) {
  73                 dprintk("substream was NULL\n");
  74                 return;
  75         }
  76
  77         runtime = substream->runtime;
  78         if (runtime == NULL) {
  79                 dprintk("runtime was NULL\n");
  80                 return;
  81         }
  82
  83         stride = runtime->frame_bits >> 3;
  84         if (stride == 0) {
  85                 dprintk("stride is zero\n");
  86                 return;
  87         }
  88
  89         length = num_bytes / stride;
  90         if (length == 0) {
  91                 dprintk("%s: length was zero\n", __func__);
  92                 return;
  93         }
  94
  95         if (runtime->dma_area == NULL) {
  96                 dprintk("dma area was NULL - ignoring\n");
  97                 return;
  98         }
  99
 100         oldptr = cxsc->hwptr_done_capture;
 101         if (oldptr + length >= runtime->buffer_size) {
 102                 unsigned int cnt =
 103                         runtime->buffer_size - oldptr;
 104                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 105                        cnt * stride);
 106                 memcpy(runtime->dma_area, pcm_data + cnt * stride,
 107                        length * stride - cnt * stride);
 108         } else {
 109                 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 110                        length * stride);
 111         }
 112         snd_pcm_stream_lock(substream);
 113
 114         cxsc->hwptr_done_capture += length;
 115         if (cxsc->hwptr_done_capture >=
 116             runtime->buffer_size)
 117                 cxsc->hwptr_done_capture -=
 118                         runtime->buffer_size;
 119
 120         cxsc->capture_transfer_done += length;
 121         if (cxsc->capture_transfer_done >=
 122             runtime->period_size) {
 123                 cxsc->capture_transfer_done -=
 124                         runtime->period_size;
 125                 period_elapsed = 1;
 126         }
 127
 128         snd_pcm_stream_unlock(substream);
 129
 130         if (period_elapsed)
 131                 snd_pcm_period_elapsed(substream);
 132 }
 133
 134 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
 135 {
 136         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 137         struct snd_pcm_runtime *runtime = substream->runtime;
 138         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 139         struct cx18 *cx = to_cx18(v4l2_dev);
 140         struct cx18_stream *s;
 141         struct cx18_open_id item;
 142         int ret;
 143
 144         /* Instruct the cx18 to start sending packets */
 145         snd_cx18_lock(cxsc);
 146         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 147
 148         item.cx = cx;
 149         item.type = s->type;
 150         item.open_id = cx->open_id++;
 151
 152         /* See if the stream is available */
 153         if (cx18_claim_stream(&item, item.type)) {
 154                 /* No, it's already in use */
 155                 snd_cx18_unlock(cxsc);
 156                 return -EBUSY;
 157         }
 158
 159         if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 160             test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 161                 /* We're already streaming.  No additional action required */
 162                 snd_cx18_unlock(cxsc);
 163                 return 0;
 164         }
 165
 166
 167         runtime->hw = snd_cx18_hw_capture;
 168         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 169         cxsc->capture_pcm_substream = substream;
 170         runtime->private_data = cx;
 171
 172         cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
 173
 174         /* Not currently streaming, so start it up */
 175         set_bit(CX18_F_S_STREAMING, &s->s_flags);
 176         ret = cx18_start_v4l2_encode_stream(s);
 177         snd_cx18_unlock(cxsc);
 178
 179         return ret;
 180 }
 181
 182 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
 183 {
 184         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 185         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 186         struct cx18 *cx = to_cx18(v4l2_dev);
 187         struct cx18_stream *s;
 188
 189         /* Instruct the cx18 to stop sending packets */
 190         snd_cx18_lock(cxsc);
 191         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 192         cx18_stop_v4l2_encode_stream(s, 0);
 193         clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 194
 195         cx18_release_stream(s);
 196
 197         cx->pcm_announce_callback = NULL;
 198         snd_cx18_unlock(cxsc);
 199
 200         return 0;
 201 }
 202
 203 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
 204 {
 205         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 206
 207         cxsc->hwptr_done_capture = 0;
 208         cxsc->capture_transfer_done = 0;
 209
 210         return 0;
 211 }
 212
 213 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 214 {
 215         return 0;
 216 }
 217
 218 static
 219 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
 220 {
 221         unsigned long flags;
 222         snd_pcm_uframes_t hwptr_done;
 223         struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
 224
 225         spin_lock_irqsave(&cxsc->slock, flags);
 226         hwptr_done = cxsc->hwptr_done_capture;
 227         spin_unlock_irqrestore(&cxsc->slock, flags);
 228
 229         return hwptr_done;
 230 }
 231
 232 static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
 233         .open           = snd_cx18_pcm_capture_open,
 234         .close          = snd_cx18_pcm_capture_close,
 235         .prepare        = snd_cx18_pcm_prepare,
 236         .trigger        = snd_cx18_pcm_trigger,
 237         .pointer        = snd_cx18_pcm_pointer,
 238 };
 239
 240 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
 241 {
 242         struct snd_pcm *sp;
 243         struct snd_card *sc = cxsc->sc;
 244         struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
 245         struct cx18 *cx = to_cx18(v4l2_dev);
 246         int ret;
 247
 248         ret = snd_pcm_new(sc, "CX23418 PCM",
 249                           0, /* PCM device 0, the only one for this card */
 250                           0, /* 0 playback substreams */
 251                           1, /* 1 capture substream */
 252                           &sp);
 253         if (ret) {
 254                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 255                               __func__, ret);
 256                 goto err_exit;
 257         }
 258
 259         spin_lock_init(&cxsc->slock);
 260
 261         snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 262                         &snd_cx18_pcm_capture_ops);
 263         snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
 264         sp->info_flags = 0;
 265         sp->private_data = cxsc;
 266         strscpy(sp->name, cx->card_name, sizeof(sp->name));
 267
 268         return 0;
 269
 270 err_exit:
 271         return ret;
 272 }