C++ (Cpp) snd_pcm_hw_constraint_pow2 Examples

Example #1

File: cx23885-alsa.c Project: 020gzh/linux

/*
 * audio pcm capture open callback
 */
static int snd_cx23885_pcm_open(struct snd_pcm_substream *substream)
{
	struct cx23885_audio_dev *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;

	if (!chip) {
		printk(KERN_ERR "BUG: cx23885 can't find device struct."
				" Can't proceed with open\n");
		return -ENODEV;
	}

	err = snd_pcm_hw_constraint_pow2(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIODS);
	if (err < 0)
		goto _error;

	chip->substream = substream;

	runtime->hw = snd_cx23885_digital_hw;

	if (chip->dev->sram_channels[AUDIO_SRAM_CHANNEL].fifo_size !=
		DEFAULT_FIFO_SIZE) {
		unsigned int bpl = chip->dev->
			sram_channels[AUDIO_SRAM_CHANNEL].fifo_size / 4;
		bpl &= ~7; /* must be multiple of 8 */
		runtime->hw.period_bytes_min = bpl;
		runtime->hw.period_bytes_max = bpl;
	}

	return 0;
_error:
	dprintk(1, "Error opening PCM!\n");
	return err;
}

Example #2

/* open callback */
static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
{
	vortex_t *vortex = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	
	/* Force equal size periods */
	if ((err =
	     snd_pcm_hw_constraint_integer(runtime,
					   SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
		return err;
	/* Avoid PAGE_SIZE boundary to fall inside of a period. */
	if ((err =
	     snd_pcm_hw_constraint_pow2(runtime, 0,
					SNDRV_PCM_HW_PARAM_PERIOD_BYTES)) < 0)
		return err;

	if (VORTEX_PCM_TYPE(substream->pcm) != VORTEX_PCM_WT) {
#ifndef CHIP_AU8820
		if (VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_A3D) {
			runtime->hw = snd_vortex_playback_hw_a3d;
		}
#endif
		if (VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_SPDIF) {
			runtime->hw = snd_vortex_playback_hw_spdif;
			switch (vortex->spdif_sr) {
			case 32000:
				runtime->hw.rates = SNDRV_PCM_RATE_32000;
				break;
			case 44100:
				runtime->hw.rates = SNDRV_PCM_RATE_44100;
				break;
			case 48000:
				runtime->hw.rates = SNDRV_PCM_RATE_48000;
				break;
			}
		}
		if (VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB
		    || VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_I2S)
			runtime->hw = snd_vortex_playback_hw_adb;
#ifdef CHIP_AU8830
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
                        VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB) {
                        runtime->hw.channels_max = 4;
                        snd_pcm_hw_constraint_list(runtime, 0,
                                SNDRV_PCM_HW_PARAM_CHANNELS,
                                &hw_constraints_au8830_channels);
                }
#endif
		substream->runtime->private_data = NULL;
	}
#ifndef CHIP_AU8810
	else {
		runtime->hw = snd_vortex_playback_hw_wt;
		substream->runtime->private_data = NULL;
	}
#endif
	return 0;
}

Example #3

File: smi2021_audio.c Project: Manouchehri/smi2021

static int smi2021_pcm_open(struct snd_pcm_substream *substream)
{
	struct smi2021 *smi2021 = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int rc;

	rc = snd_pcm_hw_constraint_pow2(runtime, 0,
					SNDRV_PCM_HW_PARAM_PERIODS);
	if (rc < 0)
		return rc;

	smi2021->pcm_substream = substream;

	runtime->hw = smi2021_pcm_hw;
	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);

	return 0;
}

Example #4

/*
 * audio pcm capture open callback
 */
static int snd_tm6000_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_tm6000_card *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;

	err = snd_pcm_hw_constraint_pow2(runtime, 0,
					 SNDRV_PCM_HW_PARAM_PERIODS);
	if (err < 0)
		goto _error;

	chip->substream = substream;

	runtime->hw = snd_tm6000_digital_hw;

	return 0;
_error:
	dprintk(1, "Error opening PCM!\n");
	return err;
}