Quelle  snd-go7007.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>

#include "go7007-priv.h"

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
module_param_array(id, charp, NULL, 0444);
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the go7007 audio driver");
MODULE_PARM_DESC(id, "ID string for the go7007 audio driver");
MODULE_PARM_DESC(enable, "Enable for the go7007 audio driver");

struct go7007_snd {
 struct snd_card *card;
 struct snd_pcm *pcm;
 struct snd_pcm_substream *substream;
 spinlock_t lock;
 int w_idx;
 int hw_ptr;
 int avail;
 int capturing;
};

static const struct snd_pcm_hardware go7007_snd_capture_hw = {
 .info   = (SNDRV_PCM_INFO_MMAP |
     SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID),
 .formats  = SNDRV_PCM_FMTBIT_S16_LE,
 .rates   = SNDRV_PCM_RATE_48000,
 .rate_min  = 48000,
 .rate_max  = 48000,
 .channels_min  = 2,
 .channels_max  = 2,
 .buffer_bytes_max = (128*1024),
 .period_bytes_min = 4096,
 .period_bytes_max = (128*1024),
 .periods_min  = 1,
 .periods_max  = 32,
};

static void parse_audio_stream_data(struct go7007 *go, u8 *buf, int length)
{
 struct go7007_snd *gosnd = go->snd_context;
 struct snd_pcm_runtime *runtime = gosnd->substream->runtime;
 int frames = bytes_to_frames(runtime, length);
 unsigned long flags;

 spin_lock_irqsave(&gosnd->lock, flags);
 gosnd->hw_ptr += frames;
 if (gosnd->hw_ptr >= runtime->buffer_size)
  gosnd->hw_ptr -= runtime->buffer_size;
 gosnd->avail += frames;
 spin_unlock_irqrestore(&gosnd->lock, flags);
 if (gosnd->w_idx + length > runtime->dma_bytes) {
  int cpy = runtime->dma_bytes - gosnd->w_idx;

  memcpy(runtime->dma_area + gosnd->w_idx, buf, cpy);
  length -= cpy;
  buf += cpy;
  gosnd->w_idx = 0;
 }
 memcpy(runtime->dma_area + gosnd->w_idx, buf, length);
 gosnd->w_idx += length;
 spin_lock_irqsave(&gosnd->lock, flags);
 if (gosnd->avail < runtime->period_size) {
  spin_unlock_irqrestore(&gosnd->lock, flags);
  return;
 }
 gosnd->avail -= runtime->period_size;
 spin_unlock_irqrestore(&gosnd->lock, flags);
 if (gosnd->capturing)
  snd_pcm_period_elapsed(gosnd->substream);
}

static int go7007_snd_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *hw_params)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);

 go->audio_deliver = parse_audio_stream_data;
 return 0;
}

static int go7007_snd_hw_free(struct snd_pcm_substream *substream)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);

 go->audio_deliver = NULL;
 return 0;
}

static int go7007_snd_capture_open(struct snd_pcm_substream *substream)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);
 struct go7007_snd *gosnd = go->snd_context;
 unsigned long flags;
 int r;

 spin_lock_irqsave(&gosnd->lock, flags);
 if (gosnd->substream == NULL) {
  gosnd->substream = substream;
  substream->runtime->hw = go7007_snd_capture_hw;
  r = 0;
 } else
  r = -EBUSY;
 spin_unlock_irqrestore(&gosnd->lock, flags);
 return r;
}

static int go7007_snd_capture_close(struct snd_pcm_substream *substream)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);
 struct go7007_snd *gosnd = go->snd_context;

 gosnd->substream = NULL;
 return 0;
}

static int go7007_snd_pcm_prepare(struct snd_pcm_substream *substream)
{
 return 0;
}

static int go7007_snd_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);
 struct go7007_snd *gosnd = go->snd_context;

 switch (cmd) {
 case SNDRV_PCM_TRIGGER_START:
  /* Just set a flag to indicate we should signal ALSA when
 * sound comes in */
  gosnd->capturing = 1;
  return 0;
 case SNDRV_PCM_TRIGGER_STOP:
  gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
  gosnd->capturing = 0;
  return 0;
 default:
  return -EINVAL;
 }
}

static snd_pcm_uframes_t go7007_snd_pcm_pointer(struct snd_pcm_substream *substream)
{
 struct go7007 *go = snd_pcm_substream_chip(substream);
 struct go7007_snd *gosnd = go->snd_context;

 return gosnd->hw_ptr;
}

static const struct snd_pcm_ops go7007_snd_capture_ops = {
 .open  = go7007_snd_capture_open,
 .close  = go7007_snd_capture_close,
 .hw_params = go7007_snd_hw_params,
 .hw_free = go7007_snd_hw_free,
 .prepare = go7007_snd_pcm_prepare,
 .trigger = go7007_snd_pcm_trigger,
 .pointer = go7007_snd_pcm_pointer,
};

static int go7007_snd_free(struct snd_device *device)
{
 struct go7007 *go = device->device_data;

 kfree(go->snd_context);
 go->snd_context = NULL;
 return 0;
}

static const struct snd_device_ops go7007_snd_device_ops = {
 .dev_free = go7007_snd_free,
};

int go7007_snd_init(struct go7007 *go)
{
 static int dev;
 struct go7007_snd *gosnd;
 int ret;

 if (dev >= SNDRV_CARDS)
  return -ENODEV;
 if (!enable[dev]) {
  dev++;
  return -ENOENT;
 }
 gosnd = kmalloc(sizeof(struct go7007_snd), GFP_KERNEL);
 if (gosnd == NULL)
  return -ENOMEM;
 spin_lock_init(&gosnd->lock);
 gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
 gosnd->capturing = 0;
 ret = snd_card_new(go->dev, index[dev], id[dev], THIS_MODULE, 0,
      &gosnd->card);
 if (ret < 0)
  goto free_snd;

 ret = snd_device_new(gosnd->card, SNDRV_DEV_LOWLEVEL, go,
   &go7007_snd_device_ops);
 if (ret < 0)
  goto free_card;

 ret = snd_pcm_new(gosnd->card, "go7007", 0, 0, 1, &gosnd->pcm);
 if (ret < 0)
  goto free_card;

 strscpy(gosnd->card->driver, "go7007", sizeof(gosnd->card->driver));
 strscpy(gosnd->card->shortname, go->name, sizeof(gosnd->card->shortname));
 strscpy(gosnd->card->longname, gosnd->card->shortname,
  sizeof(gosnd->card->longname));

 gosnd->pcm->private_data = go;
 snd_pcm_set_ops(gosnd->pcm, SNDRV_PCM_STREAM_CAPTURE,
   &go7007_snd_capture_ops);
 snd_pcm_set_managed_buffer_all(gosnd->pcm, SNDRV_DMA_TYPE_VMALLOC,
           NULL, 0, 0);

 ret = snd_card_register(gosnd->card);
 if (ret < 0)
  goto free_card;

 gosnd->substream = NULL;
 go->snd_context = gosnd;
 v4l2_device_get(&go->v4l2_dev);
 ++dev;

 return 0;

free_card:
 snd_card_free(gosnd->card);
free_snd:
 kfree(gosnd);
 return ret;
}
EXPORT_SYMBOL(go7007_snd_init);

int go7007_snd_remove(struct go7007 *go)
{
 struct go7007_snd *gosnd = go->snd_context;

 snd_card_disconnect(gosnd->card);
 snd_card_free_when_closed(gosnd->card);
 v4l2_device_put(&go->v4l2_dev);
 return 0;
}
EXPORT_SYMBOL(go7007_snd_remove);

MODULE_LICENSE("GPL v2");