C++ snd_pcm_hw_constraint_step函数代码示例

static int cygnus_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct cygnus_aio_port *aio;
	int ret;

	aio = cygnus_dai_get_dma_data(substream);
	if (!aio)
		return -ENODEV;

	dev_dbg(rtd->cpu_dai->dev, "%s port %d\n", __func__, aio->portnum);

	snd_soc_set_runtime_hwparams(substream, &cygnus_pcm_hw);

	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, PERIOD_BYTES_MIN);
	if (ret < 0)
		return ret;

	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, PERIOD_BYTES_MIN);
	if (ret < 0)
		return ret;
	/*
	 * Keep track of which substream belongs to which port.
	 * This info is needed by snd_pcm_period_elapsed() in irq_handler
	 */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		aio->play_stream = substream;
	else
		aio->capture_stream = substream;

	return 0;
}

static int lola_pcm_open(struct snd_pcm_substream *substream)
{
	struct lola *chip = snd_pcm_substream_chip(substream);
	struct lola_pcm *pcm = lola_get_pcm(substream);
	struct lola_stream *str = lola_get_stream(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;

	mutex_lock(&chip->open_mutex);
	if (str->opened) {
		mutex_unlock(&chip->open_mutex);
		return -EBUSY;
	}
	str->substream = substream;
	str->master = NULL;
	str->opened = 1;
	runtime->hw = lola_pcm_hw;
	runtime->hw.channels_max = pcm->num_streams - str->index;
	if (chip->sample_rate) {
		/* sample rate is locked */
		runtime->hw.rate_min = chip->sample_rate;
		runtime->hw.rate_max = chip->sample_rate;
	} else {
		runtime->hw.rate_min = chip->sample_rate_min;
		runtime->hw.rate_max = chip->sample_rate_max;
	}
	chip->ref_count_rate++;
	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
	/* period size = multiple of chip->granularity (8, 16 or 32 frames)*/
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
				   chip->granularity);
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
				   chip->granularity);
	mutex_unlock(&chip->open_mutex);
	return 0;
}

static int msm_lsm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct lsm_priv *prtd;
	int ret = 0;

	pr_debug("%s\n", __func__);
	prtd = kzalloc(sizeof(struct lsm_priv), GFP_KERNEL);
	if (!prtd) {
		pr_err("%s: Failed to allocate memory for lsm_priv\n",
		       __func__);
		return -ENOMEM;
	}
	spin_lock_init(&prtd->event_lock);
	init_waitqueue_head(&prtd->event_wait);
	prtd->substream = substream;
	runtime->private_data = prtd;
	runtime->hw = msm_pcm_hardware_capture;

	ret = snd_pcm_hw_constraint_list(runtime, 0,
				SNDRV_PCM_HW_PARAM_RATE,
				&constraints_sample_rates);
	if (ret < 0)
		pr_info("%s: snd_pcm_hw_constraint_list failed ret %d\n",
			 __func__, ret);
	/* Ensure that buffer size is a multiple of period size */
	ret = snd_pcm_hw_constraint_integer(runtime,
			    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		pr_info("%s: snd_pcm_hw_constraint_integer failed ret %d\n",
			__func__, ret);

	ret = snd_pcm_hw_constraint_minmax(runtime,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
		CAPTURE_MIN_NUM_PERIODS * CAPTURE_MIN_PERIOD_SIZE,
		CAPTURE_MAX_NUM_PERIODS * CAPTURE_MAX_PERIOD_SIZE);
	if (ret < 0)
		pr_info("%s: constraint for buffer bytes min max ret = %d\n",
			__func__, ret);
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
	if (ret < 0) {
		pr_info("%s: constraint for period bytes step ret = %d\n",
			__func__, ret);
	}
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
	if (ret < 0)
		pr_info("%s: constraint for buffer bytes step ret = %d\n",
			__func__, ret);
	prtd->lsm_client = q6lsm_client_alloc(
				(lsm_app_cb)lsm_event_handler, prtd);
	if (!prtd->lsm_client) {
		pr_err("%s: Could not allocate memory\n", __func__);
		kfree(prtd);
		runtime->private_data = NULL;
		return -ENOMEM;
	}
	return 0;
}

static int pxa910_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_cpu_dai *cpu_dai = rtd->dai->cpu_dai;
	struct pxa910_runtime_data *prtd;
	int ret;

	snd_soc_set_runtime_hwparams(substream, &pxa910_pcm_hardware);

	/*
	 * For mysterious reasons (and despite what the manual says)
	 * playback samples are lost if the DMA count is not a multiple
	 * of the DMA burst size.  Let's add a rule to enforce that.
	 */
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
	if (ret)
		goto out;

	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
	if (ret)
		goto out;

	ret = snd_pcm_hw_constraint_integer(runtime,
					SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto out;

	prtd = kzalloc(sizeof(struct pxa910_runtime_data), GFP_KERNEL);
	if (prtd == NULL) {
		ret = -ENOMEM;
		goto out;
	}

	prtd->dma_ch = -1;
	prtd->squ_desc_array =
		prtd->squ_desc_array = pxa910_sram_alloc(PAGE_SIZE, &prtd->squ_desc_array_phys);
	if (!prtd->squ_desc_array) {
		ret = -ENOMEM;
		goto err1;
	}

	runtime->private_data = prtd;
	return 0;

 err1:
	kfree(prtd);
 out:
	return ret;
}

static int hdmi_dai_startup(struct snd_pcm_substream *substream,
			    struct snd_soc_dai *dai)
{
	struct hdmi_audio_data *ad = card_drvdata_substream(substream);
	int ret;
	/*
	 * Make sure that the period bytes are multiple of the DMA packet size.
	 * Largest packet size we use is 32 32-bit words = 128 bytes
	 */
	ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
					 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
	if (ret < 0) {
		dev_err(dai->dev, "could not apply constraint\n");
		return ret;
	}

	snd_soc_dai_set_dma_data(dai, substream, &ad->dma_data);

	mutex_lock(&ad->current_stream_lock);
	ad->current_stream = substream;
	mutex_unlock(&ad->current_stream_lock);

	ret = ad->ops->audio_startup(ad->dssdev, hdmi_dai_abort);

	if (ret) {
		mutex_lock(&ad->current_stream_lock);
		ad->current_stream = NULL;
		mutex_unlock(&ad->current_stream_lock);
	}

	return ret;
}

/* open_playback callback */
static int snd_ca0106_pcm_open_playback_channel(snd_pcm_substream_t *substream, int channel_id)
{
	ca0106_t *chip = snd_pcm_substream_chip(substream);
        ca0106_channel_t *channel = &(chip->playback_channels[channel_id]);
	ca0106_pcm_t *epcm;
	snd_pcm_runtime_t *runtime = substream->runtime;
	int err;

	epcm = kzalloc(sizeof(*epcm), GFP_KERNEL);

	if (epcm == NULL)
		return -ENOMEM;
	epcm->emu = chip;
	epcm->substream = substream;
        epcm->channel_id=channel_id;
  
	runtime->private_data = epcm;
	runtime->private_free = snd_ca0106_pcm_free_substream;
  
	runtime->hw = snd_ca0106_playback_hw;

        channel->emu = chip;
        channel->number = channel_id;

        channel->use=1;
        //printk("open:channel_id=%d, chip=%p, channel=%p\n",channel_id, chip, channel);
        //channel->interrupt = snd_ca0106_pcm_channel_interrupt;
        channel->epcm=epcm;
	if ((err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
                return err;
	if ((err = snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 64)) < 0)
                return err;
	return 0;
}

static int omap_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct omap_runtime_data *prtd;
	int ret;

	snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);

	/* Ensure that buffer size is a multiple of period size */
	ret = snd_pcm_hw_constraint_integer(runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto out;

	if (cpu_is_omap44xx()) {
		/* ABE needs a step of 24 * 4 data bits, and HDMI 32 * 4
		 * Ensure buffer size satisfies both constraints.
		 */
		ret = snd_pcm_hw_constraint_step(runtime, 0,
					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 384);
		if (ret < 0)
			goto out;
	} 

	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	if (prtd == NULL) {
		ret = -ENOMEM;
		goto out;
	}
	spin_lock_init(&prtd->lock);
	runtime->private_data = prtd;

out:
	return ret;
}

int __pxa2xx_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct pxa2xx_runtime_data *rtd;
	int ret;

	runtime->hw = pxa2xx_pcm_hardware;

	/*
                                                             
                                                                
                                                             
  */
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
	if (ret)
		goto out;

	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
	if (ret)
		goto out;

	ret = snd_pcm_hw_constraint_integer(runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto out;

	ret = -ENOMEM;
	rtd = kzalloc(sizeof(*rtd), GFP_KERNEL);
	if (!rtd)
		goto out;
	rtd->dma_desc_array =
		dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
				       &rtd->dma_desc_array_phys, GFP_KERNEL);
	if (!rtd->dma_desc_array)
		goto err1;

	rtd->dma_ch = -1;
	runtime->private_data = rtd;
	return 0;

 err1:
	kfree(rtd);
 out:
	return ret;
}

static int tegra_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct tegra_runtime_data *prtd;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct tegra_pcm_dma_params * dmap;
	int ret = 0;

	prtd = kzalloc(sizeof(struct tegra_runtime_data), GFP_KERNEL);
	if (prtd == NULL)
		return -ENOMEM;

	runtime->private_data = prtd;
	prtd->substream = substream;

	spin_lock_init(&prtd->lock);

	dmap = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if (dmap) {
		prtd->dma_req[0].dev = prtd;
		prtd->dma_req[1].dev = prtd;

		prtd->dma_chan = tegra_dma_allocate_channel(
					TEGRA_DMA_MODE_CONTINUOUS_SINGLE,
					"pcm");
		if (prtd->dma_chan == NULL) {
			ret = -ENOMEM;
			goto err;
		}
	}

	/* Set HW params now that initialization is complete */
	snd_soc_set_runtime_hwparams(substream, &tegra_pcm_hardware);

	/* Ensure period size is multiple of 8 */
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 0x8);
	if (ret < 0)
		goto err;

	/* Ensure that buffer size is a multiple of period size */
	ret = snd_pcm_hw_constraint_integer(runtime,
						SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto err;

	return 0;

err:
	if (prtd->dma_chan) {
		tegra_dma_free_channel(prtd->dma_chan);
	}

	kfree(prtd);

	return ret;
}

static int lx_pcm_open(struct snd_pcm_substream *substream)
{
	struct lx6464es *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err = 0;
	int board_rate;

	dev_dbg(chip->card->dev, "->lx_pcm_open\n");
	mutex_lock(&chip->setup_mutex);

	/* copy the struct snd_pcm_hardware struct */
	runtime->hw = lx_caps;

#if 0
	/* buffer-size should better be multiple of period-size */
	err = snd_pcm_hw_constraint_integer(runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (err < 0) {
		dev_warn(chip->card->dev, "could not constrain periods\n");
		goto exit;
	}
#endif

	/* the clock rate cannot be changed */
	board_rate = chip->board_sample_rate;
	err = snd_pcm_hw_constraint_single(runtime, SNDRV_PCM_HW_PARAM_RATE,
					   board_rate);

	if (err < 0) {
		dev_warn(chip->card->dev, "could not constrain periods\n");
		goto exit;
	}

	/* constrain period size */
	err = snd_pcm_hw_constraint_minmax(runtime,
					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
					   MICROBLAZE_IBL_MIN,
					   MICROBLAZE_IBL_MAX);
	if (err < 0) {
		dev_warn(chip->card->dev,
			   "could not constrain period size\n");
		goto exit;
	}

	snd_pcm_hw_constraint_step(runtime, 0,
				   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);

	snd_pcm_set_sync(substream);
	err = 0;

exit:
	runtime->private_data = chip;

	mutex_unlock(&chip->setup_mutex);
	dev_dbg(chip->card->dev, "<-lx_pcm_open, %d\n", err);
	return err;
}

static int cns3xxx_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct cns3xxx_runtime_data *prtd;
	int ret;

#ifdef __DEBUG_PATH
	printk("%s=>%d\n", __FUNCTION__, __LINE__);
#endif

	snd_soc_set_runtime_hwparams(substream, &cns3xxx_pcm_hardware);

    /* Enforcing the constraint that period bytes are a multiple of 16 bytes.
     * This helps PL330 GDMA innerloop
     */
    ret = snd_pcm_hw_constraint_step (runtime, 0, 
                                      SNDRV_PCM_HW_PARAM_PERIOD_BYTES,16);
    if (ret) goto out;

    ret = snd_pcm_hw_constraint_step (runtime,0,
                                      SNDRV_PCM_HW_PARAM_BUFFER_BYTES,16);
    if (ret) goto out;

    /* To ensure that buffersize is a multiple of period size ? */
	ret = snd_pcm_hw_constraint_integer (runtime, SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto out;

	prtd = kzalloc(sizeof(struct cns3xxx_runtime_data), GFP_KERNEL);
	if (prtd == NULL) {
		ret = -ENOMEM;
		goto out;
	}
    prtd->dma_ch = -1;

	runtime->private_data = prtd;
	return 0;

 out:
	printk("%s=>%d\n", __FUNCTION__, __LINE__);
	return ret;
}

static int omap_hdmi_dai_startup(struct snd_pcm_substream *substream,
				  struct snd_soc_dai *dai)
{
	int err;
	err = snd_pcm_hw_constraint_step(substream->runtime, 0,
				 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
	if (err < 0)
		return err;

	return 0;
}

static int aess_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct omap_abe *abe = snd_soc_platform_get_drvdata(platform);
	struct snd_soc_dai *dai = rtd->cpu_dai;
	int ret = 0;

	mutex_lock(&abe->mutex);

	dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name);

	switch (dai->id) {
	case OMAP_ABE_FRONTEND_DAI_MODEM:
		break;
	case OMAP_ABE_FRONTEND_DAI_LP_MEDIA:
		snd_soc_set_runtime_hwparams(substream, &omap_abe_hardware);
		ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 1024);
		break;
	default:
		/*
		 * Period size must be aligned with the Audio Engine
		 * processing loop which is 250 us long
		 */
		ret = snd_pcm_hw_rule_add(substream->runtime, 0,
					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
					omap_abe_hwrule_period_step,
					NULL,
					SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
		break;
	}

	if (ret < 0) {
		dev_err(abe->dev, "failed to set period constraints for DAI %d\n",
			dai->id);
		goto out;
	}

	omap_abe_pm_runtime_get_sync(abe);

	if (!abe->active++) {
		abe->opp.level = 0;
		ret = abe_pm_restore_context(abe);
		if (ret)
			goto out;
		omap_aess_wakeup(abe->aess);
	}

out:
	mutex_unlock(&abe->mutex);
	return ret;
}

static int omap_hdmi_dai_startup(struct snd_pcm_substream *substream,
                                 struct snd_soc_dai *dai)
{
    int err;
    /*
     * Make sure that the period bytes are multiple of the DMA packet size.
     * Largest packet size we use is 32 32-bit words = 128 bytes
     */
    err = snd_pcm_hw_constraint_step(substream->runtime, 0,
                                     SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
    if (err < 0)
        return err;

    return 0;
}

static int omap_mcbsp_dai_startup(struct snd_pcm_substream *substream,
				  struct snd_soc_dai *cpu_dai)
{
	struct omap_mcbsp_data *mcbsp_data = snd_soc_dai_get_drvdata(cpu_dai);
	int bus_id = mcbsp_data->bus_id;
	int err = 0;

	if (!cpu_dai->active) {
		err = omap_mcbsp_request(bus_id);
		cpu_dai->active = 1;
	}

	/*
	 * OMAP3 McBSP FIFO is word structured.
	 * McBSP2 has 1024 + 256 = 1280 word long buffer,
	 * McBSP1,3,4,5 has 128 word long buffer
	 * This means that the size of the FIFO depends on the sample format.
	 * For example on McBSP3:
	 * 16bit samples: size is 128 * 2 = 256 bytes
	 * 32bit samples: size is 128 * 4 = 512 bytes
	 * It is simpler to place constraint for buffer and period based on
	 * channels.
	 * McBSP3 as example again (16 or 32 bit samples):
	 * 1 channel (mono): size is 128 frames (128 words)
	 * 2 channels (stereo): size is 128 / 2 = 64 frames (2 * 64 words)
	 * 4 channels: size is 128 / 4 = 32 frames (4 * 32 words)
	 */
	if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
		/*
		* Rule for the buffer size. We should not allow
		* smaller buffer than the FIFO size to avoid underruns
		*/
#if 0 // FIXME: All BE must support hw_rules and constraints */
		snd_pcm_hw_rule_add(substream->runtime, 0,
				    SNDRV_PCM_HW_PARAM_CHANNELS,
				    omap_mcbsp_hwrule_min_buffersize,
				    mcbsp_data,
				    SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);

		/* Make sure, that the period size is always even */
		snd_pcm_hw_constraint_step(substream->runtime, 0,
					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
#endif
	}

	return err;
}