linux/drivers/media/pci/ivtv/ivtv-alsa-pcm.c
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   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 <linux/vmalloc.h>
  20
  21#include <sound/core.h>
  22#include <sound/pcm.h>
  23
  24
  25static unsigned int pcm_debug;
  26module_param(pcm_debug, int, 0644);
  27MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
  28
  29#define dprintk(fmt, arg...) \
  30        do { \
  31                if (pcm_debug) \
  32                        pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
  33        } while (0)
  34
  35static const struct snd_pcm_hardware snd_ivtv_hw_capture = {
  36        .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
  37                SNDRV_PCM_INFO_MMAP           |
  38                SNDRV_PCM_INFO_INTERLEAVED    |
  39                SNDRV_PCM_INFO_MMAP_VALID,
  40
  41        .formats = SNDRV_PCM_FMTBIT_S16_LE,
  42
  43        .rates = SNDRV_PCM_RATE_48000,
  44
  45        .rate_min = 48000,
  46        .rate_max = 48000,
  47        .channels_min = 2,
  48        .channels_max = 2,
  49        .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
  50        .period_bytes_min = 64,         /* 12544/2, */
  51        .period_bytes_max = 12544,
  52        .periods_min = 2,
  53        .periods_max = 98,              /* 12544, */
  54};
  55
  56static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
  57                                        u8 *pcm_data,
  58                                        size_t num_bytes)
  59{
  60        struct snd_pcm_substream *substream;
  61        struct snd_pcm_runtime *runtime;
  62        unsigned int oldptr;
  63        unsigned int stride;
  64        int period_elapsed = 0;
  65        int length;
  66
  67        dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
  68                pcm_data, num_bytes);
  69
  70        substream = itvsc->capture_pcm_substream;
  71        if (substream == NULL) {
  72                dprintk("substream was NULL\n");
  73                return;
  74        }
  75
  76        runtime = substream->runtime;
  77        if (runtime == NULL) {
  78                dprintk("runtime was NULL\n");
  79                return;
  80        }
  81
  82        stride = runtime->frame_bits >> 3;
  83        if (stride == 0) {
  84                dprintk("stride is zero\n");
  85                return;
  86        }
  87
  88        length = num_bytes / stride;
  89        if (length == 0) {
  90                dprintk("%s: length was zero\n", __func__);
  91                return;
  92        }
  93
  94        if (runtime->dma_area == NULL) {
  95                dprintk("dma area was NULL - ignoring\n");
  96                return;
  97        }
  98
  99        oldptr = itvsc->hwptr_done_capture;
 100        if (oldptr + length >= runtime->buffer_size) {
 101                unsigned int cnt =
 102                        runtime->buffer_size - oldptr;
 103                memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 104                       cnt * stride);
 105                memcpy(runtime->dma_area, pcm_data + cnt * stride,
 106                       length * stride - cnt * stride);
 107        } else {
 108                memcpy(runtime->dma_area + oldptr * stride, pcm_data,
 109                       length * stride);
 110        }
 111        snd_pcm_stream_lock(substream);
 112
 113        itvsc->hwptr_done_capture += length;
 114        if (itvsc->hwptr_done_capture >=
 115            runtime->buffer_size)
 116                itvsc->hwptr_done_capture -=
 117                        runtime->buffer_size;
 118
 119        itvsc->capture_transfer_done += length;
 120        if (itvsc->capture_transfer_done >=
 121            runtime->period_size) {
 122                itvsc->capture_transfer_done -=
 123                        runtime->period_size;
 124                period_elapsed = 1;
 125        }
 126
 127        snd_pcm_stream_unlock(substream);
 128
 129        if (period_elapsed)
 130                snd_pcm_period_elapsed(substream);
 131}
 132
 133static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
 134{
 135        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 136        struct snd_pcm_runtime *runtime = substream->runtime;
 137        struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 138        struct ivtv *itv = to_ivtv(v4l2_dev);
 139        struct ivtv_stream *s;
 140        struct ivtv_open_id item;
 141        int ret;
 142
 143        /* Instruct the CX2341[56] to start sending packets */
 144        snd_ivtv_lock(itvsc);
 145
 146        if (ivtv_init_on_first_open(itv)) {
 147                snd_ivtv_unlock(itvsc);
 148                return -ENXIO;
 149        }
 150
 151        s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 152
 153        v4l2_fh_init(&item.fh, &s->vdev);
 154        item.itv = itv;
 155        item.type = s->type;
 156
 157        /* See if the stream is available */
 158        if (ivtv_claim_stream(&item, item.type)) {
 159                /* No, it's already in use */
 160                v4l2_fh_exit(&item.fh);
 161                snd_ivtv_unlock(itvsc);
 162                return -EBUSY;
 163        }
 164
 165        if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
 166            test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
 167                /* We're already streaming.  No additional action required */
 168                snd_ivtv_unlock(itvsc);
 169                return 0;
 170        }
 171
 172
 173        runtime->hw = snd_ivtv_hw_capture;
 174        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 175        itvsc->capture_pcm_substream = substream;
 176        runtime->private_data = itv;
 177
 178        itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
 179
 180        /* Not currently streaming, so start it up */
 181        set_bit(IVTV_F_S_STREAMING, &s->s_flags);
 182        ret = ivtv_start_v4l2_encode_stream(s);
 183        snd_ivtv_unlock(itvsc);
 184
 185        return ret;
 186}
 187
 188static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
 189{
 190        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 191        struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 192        struct ivtv *itv = to_ivtv(v4l2_dev);
 193        struct ivtv_stream *s;
 194
 195        /* Instruct the ivtv to stop sending packets */
 196        snd_ivtv_lock(itvsc);
 197        s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
 198        ivtv_stop_v4l2_encode_stream(s, 0);
 199        clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
 200
 201        ivtv_release_stream(s);
 202
 203        itv->pcm_announce_callback = NULL;
 204        snd_ivtv_unlock(itvsc);
 205
 206        return 0;
 207}
 208
 209static int snd_ivtv_pcm_ioctl(struct snd_pcm_substream *substream,
 210                     unsigned int cmd, void *arg)
 211{
 212        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 213        int ret;
 214
 215        snd_ivtv_lock(itvsc);
 216        ret = snd_pcm_lib_ioctl(substream, cmd, arg);
 217        snd_ivtv_unlock(itvsc);
 218        return ret;
 219}
 220
 221
 222static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
 223                                        size_t size)
 224{
 225        struct snd_pcm_runtime *runtime = subs->runtime;
 226
 227        dprintk("Allocating vbuffer\n");
 228        if (runtime->dma_area) {
 229                if (runtime->dma_bytes > size)
 230                        return 0;
 231
 232                vfree(runtime->dma_area);
 233        }
 234        runtime->dma_area = vmalloc(size);
 235        if (!runtime->dma_area)
 236                return -ENOMEM;
 237
 238        runtime->dma_bytes = size;
 239
 240        return 0;
 241}
 242
 243static int snd_ivtv_pcm_hw_params(struct snd_pcm_substream *substream,
 244                         struct snd_pcm_hw_params *params)
 245{
 246        dprintk("%s called\n", __func__);
 247
 248        return snd_pcm_alloc_vmalloc_buffer(substream,
 249                                           params_buffer_bytes(params));
 250}
 251
 252static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream)
 253{
 254        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 255        unsigned long flags;
 256        unsigned char *dma_area = NULL;
 257
 258        spin_lock_irqsave(&itvsc->slock, flags);
 259        if (substream->runtime->dma_area) {
 260                dprintk("freeing pcm capture region\n");
 261                dma_area = substream->runtime->dma_area;
 262                substream->runtime->dma_area = NULL;
 263        }
 264        spin_unlock_irqrestore(&itvsc->slock, flags);
 265        vfree(dma_area);
 266
 267        return 0;
 268}
 269
 270static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
 271{
 272        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 273
 274        itvsc->hwptr_done_capture = 0;
 275        itvsc->capture_transfer_done = 0;
 276
 277        return 0;
 278}
 279
 280static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 281{
 282        return 0;
 283}
 284
 285static
 286snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
 287{
 288        unsigned long flags;
 289        snd_pcm_uframes_t hwptr_done;
 290        struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
 291
 292        spin_lock_irqsave(&itvsc->slock, flags);
 293        hwptr_done = itvsc->hwptr_done_capture;
 294        spin_unlock_irqrestore(&itvsc->slock, flags);
 295
 296        return hwptr_done;
 297}
 298
 299static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
 300                                             unsigned long offset)
 301{
 302        void *pageptr = subs->runtime->dma_area + offset;
 303
 304        return vmalloc_to_page(pageptr);
 305}
 306
 307static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
 308        .open           = snd_ivtv_pcm_capture_open,
 309        .close          = snd_ivtv_pcm_capture_close,
 310        .ioctl          = snd_ivtv_pcm_ioctl,
 311        .hw_params      = snd_ivtv_pcm_hw_params,
 312        .hw_free        = snd_ivtv_pcm_hw_free,
 313        .prepare        = snd_ivtv_pcm_prepare,
 314        .trigger        = snd_ivtv_pcm_trigger,
 315        .pointer        = snd_ivtv_pcm_pointer,
 316        .page           = snd_pcm_get_vmalloc_page,
 317};
 318
 319int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
 320{
 321        struct snd_pcm *sp;
 322        struct snd_card *sc = itvsc->sc;
 323        struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 324        struct ivtv *itv = to_ivtv(v4l2_dev);
 325        int ret;
 326
 327        ret = snd_pcm_new(sc, "CX2341[56] PCM",
 328                          0, /* PCM device 0, the only one for this card */
 329                          0, /* 0 playback substreams */
 330                          1, /* 1 capture substream */
 331                          &sp);
 332        if (ret) {
 333                IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
 334                              __func__, ret);
 335                goto err_exit;
 336        }
 337
 338        spin_lock_init(&itvsc->slock);
 339
 340        snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
 341                        &snd_ivtv_pcm_capture_ops);
 342        sp->info_flags = 0;
 343        sp->private_data = itvsc;
 344        strscpy(sp->name, itv->card_name, sizeof(sp->name));
 345
 346        return 0;
 347
 348err_exit:
 349        return ret;
 350}
 351