C++ params_periods函数代码示例

int tegra_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct tegra_runtime_data *prtd = runtime->private_data;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct tegra_pcm_dma_params * dmap;
	int i;

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	/* Limit dma_req_count to period count */
	if (prtd->dma_req_count > params_periods(params))
		prtd->dma_req_count = params_periods(params);
	dmap = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	if (dmap) {
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
			for (i = 0; i < prtd->dma_req_count; i++)
				setup_dma_tx_request(&prtd->dma_req[i], dmap);
		} else {
			for (i = 0; i < prtd->dma_req_count; i++)
				setup_dma_rx_request(&prtd->dma_req[i], dmap);
		}
	}
	for (i = 0; i < prtd->dma_req_count; i++)
		prtd->dma_req[i].size = params_period_bytes(params);

	return 0;
}

/*
 * hw_params callback
 */
static int snd_cx23885_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *hw_params)
{
	struct cx23885_audio_dev *chip = snd_pcm_substream_chip(substream);
	struct cx23885_audio_buffer *buf;
	int ret;

	if (substream->runtime->dma_area) {
		dsp_buffer_free(chip);
		substream->runtime->dma_area = NULL;
	}

	chip->period_size = params_period_bytes(hw_params);
	chip->num_periods = params_periods(hw_params);
	chip->dma_size = chip->period_size * params_periods(hw_params);

	BUG_ON(!chip->dma_size);
	BUG_ON(chip->num_periods & (chip->num_periods-1));

	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
	if (NULL == buf)
		return -ENOMEM;

	buf->bpl = chip->period_size;
	chip->buf = buf;

	ret = cx23885_alsa_dma_init(chip,
			(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
	if (ret < 0)
		goto error;

	ret = cx23885_alsa_dma_map(chip);
	if (ret < 0)
		goto error;

	ret = cx23885_risc_databuffer(chip->pci, &buf->risc, buf->sglist,
				   chip->period_size, chip->num_periods, 1);
	if (ret < 0)
		goto error;

	/* Loop back to start of program */
	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP|RISC_IRQ1|RISC_CNT_INC);
	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */

	substream->runtime->dma_area = chip->buf->vaddr;
	substream->runtime->dma_bytes = chip->dma_size;
	substream->runtime->dma_addr = 0;

	return 0;

error:
	kfree(buf);
	chip->buf = NULL;
	return ret;
}

static int s3c_idma_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct lpam_i2s_pdata *prtd = substream->runtime->private_data;
	unsigned long idma_totbytes;

	pr_debug("Entered %s\n", __func__);

	idma_totbytes = params_buffer_bytes(params);
	prtd->end = LP_TXBUFF_ADDR + idma_totbytes;
	prtd->period = params_periods(params);
	s3c_idma.dma_end    = prtd->end;
	s3c_idma.period_val = prtd->period;

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	memset(runtime->dma_area, 0, LP_BUFSIZE);

	runtime->dma_bytes = idma_totbytes;

	s3c_idma_setcallbk(s3c_idma_done, params_period_bytes(params));

	prtd->start = runtime->dma_addr;
	prtd->pos = prtd->start;
	prtd->end = prtd->start + idma_totbytes;

	printk("[email protected]%x Total=%lubytes PrdSz=%u #Prds=%u\n",
			prtd->start, idma_totbytes, params_period_bytes(params), prtd->period);

	return 0;
}

static int snd_atiixp_pcm_hw_params(struct snd_pcm_substream *substream,
				   struct snd_pcm_hw_params *hw_params)
{
	struct atiixp_modem *chip = snd_pcm_substream_chip(substream);
	struct atiixp_dma *dma = substream->runtime->private_data;
	int err;
	int i;

	err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
	if (err < 0)
		return err;
	dma->buf_addr = substream->runtime->dma_addr;
	dma->buf_bytes = params_buffer_bytes(hw_params);

	err = atiixp_build_dma_packets(chip, dma, substream,
				       params_periods(hw_params),
				       params_period_bytes(hw_params));
	if (err < 0)
		return err;

	/*                   */
	for (i = 0; i < NUM_ATI_CODECS; i++) {
		if (! chip->ac97[i])
			continue;
		snd_ac97_write(chip->ac97[i], AC97_LINE1_RATE, params_rate(hw_params));
		snd_ac97_write(chip->ac97[i], AC97_LINE1_LEVEL, 0);
	}

	return err;
}

static int txx9aclc_pcm_hw_params(struct snd_pcm_substream *substream,
				  struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct txx9aclc_dmadata *dmadata = runtime->private_data;
	int ret;

	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
	if (ret < 0)
		return ret;

	dev_dbg(socdev->dev,
		"runtime->dma_area = %#lx dma_addr = %#lx dma_bytes = %zd "
		"runtime->min_align %ld\n",
		(unsigned long)runtime->dma_area,
		(unsigned long)runtime->dma_addr, runtime->dma_bytes,
		runtime->min_align);
	dev_dbg(socdev->dev,
		"periods %d period_bytes %d stream %d\n",
		params_periods(params), params_period_bytes(params),
		substream->stream);

	dmadata->substream = substream;
	dmadata->pos = 0;
	return 0;
}

static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
				 struct snd_pcm_hw_params *params,
				 struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
	u32 mode;

	dev_dbg(psc_dma->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
		" periods=%i buffer_size=%i  buffer_bytes=%i\n",
		__func__, substream, params_period_size(params),
		params_period_bytes(params), params_periods(params),
		params_buffer_size(params), params_buffer_bytes(params));

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
		break;
	case SNDRV_PCM_FORMAT_S16_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
		break;
	case SNDRV_PCM_FORMAT_S24_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
		break;
	case SNDRV_PCM_FORMAT_S32_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
		break;
	default:
		dev_dbg(psc_dma->dev, "invalid format\n");
		return -EINVAL;
	}
	out_be32(&psc_dma->psc_regs->sicr, psc_dma->sicr | mode);

	return 0;
}

static int idma_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct idma_ctrl *prtd = substream->runtime->private_data;
	u32 ahb = readl(idma.regs + I2SAHB);

	pr_debug("Entered %s\n", __func__);

	ahb |= (AHB_DMARLD | AHB_INTMASK);
	writel(ahb, idma.regs + I2SAHB);

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	runtime->dma_bytes = params_buffer_bytes(params);
	memset(runtime->dma_area, 0, runtime->dma_bytes);

	prtd->start = prtd->pos = runtime->dma_addr;
	prtd->period = params_periods(params);
	prtd->periodsz = params_period_bytes(params);
	prtd->end = prtd->start + runtime->dma_bytes;

	idma_setcallbk(substream, idma_done);
#ifndef PRODUCT_SHIP
	pr_info("I:%s:[email protected]%x Total=%d PrdSz=%d #Prds=%d dma_area=0x%x\n",
		(substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ? "P" : "C",
		prtd->start, runtime->dma_bytes, prtd->periodsz,
		prtd->period, (unsigned int)runtime->dma_area);
#endif

	return 0;
}

static int idma_hw_params(struct snd_pcm_substream *substream,
                          struct snd_pcm_hw_params *params)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct idma_ctrl *prtd = substream->runtime->private_data;
    u32 mod = readl(idma.regs + I2SMOD);
    u32 ahb = readl(idma.regs + I2SAHB);

    ahb |= (AHB_DMARLD | AHB_INTMASK);
    mod |= MOD_TXS_IDMA;
    writel(ahb, idma.regs + I2SAHB);
    writel(mod, idma.regs + I2SMOD);

    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
    runtime->dma_bytes = params_buffer_bytes(params);

    prtd->start = prtd->pos = runtime->dma_addr;
    prtd->period = params_periods(params);
    prtd->periodsz = params_period_bytes(params);
    prtd->end = runtime->dma_addr + runtime->dma_bytes;

    idma_setcallbk(substream, idma_done);

    return 0;
}

static int smi2021_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *hw_params)
{
	int size, rc;
	size = params_period_bytes(hw_params) * params_periods(hw_params);

	rc = pcm_buffer_alloc(substream, size);
	if (rc < 0)
		return rc;


	return 0;
}

static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
	int i;
	unsigned long dma_addr;

	imx_ssi_dma_alloc(substream);

	iprtd->size = params_buffer_bytes(params);
	iprtd->periods = params_periods(params);
	iprtd->period = params_period_bytes(params);
	iprtd->offset = 0;
	iprtd->period_time = HZ / (params_rate(params) /
			params_period_size(params));

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	if (iprtd->sg_count != iprtd->periods) {
		kfree(iprtd->sg_list);

		iprtd->sg_list = kcalloc(iprtd->periods + 1,
				sizeof(struct scatterlist), GFP_KERNEL);
		if (!iprtd->sg_list)
			return -ENOMEM;
		iprtd->sg_count = iprtd->periods + 1;
	}

	sg_init_table(iprtd->sg_list, iprtd->sg_count);
	dma_addr = runtime->dma_addr;

	for (i = 0; i < iprtd->periods; i++) {
		iprtd->sg_list[i].page_link = 0;
		iprtd->sg_list[i].offset = 0;
		iprtd->sg_list[i].dma_address = dma_addr;
		iprtd->sg_list[i].length = iprtd->period;
		dma_addr += iprtd->period;
	}

	/* close the loop */
	iprtd->sg_list[iprtd->sg_count - 1].offset = 0;
	iprtd->sg_list[iprtd->sg_count - 1].length = 0;
	iprtd->sg_list[iprtd->sg_count - 1].page_link =
			((unsigned long) iprtd->sg_list | 0x01) & ~0x02;
	return 0;
}

static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct imx_pcm_runtime_data *iprtd = runtime->private_data;

	iprtd->size = params_buffer_bytes(params);
	iprtd->periods = params_periods(params);
	iprtd->period = params_period_bytes(params) ;
	iprtd->offset = 0;
	iprtd->last_offset = 0;
	iprtd->poll_time = HZ / (params_rate(params) / params_period_size(params));

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	return 0;
}

static int snd_cs5535audio_hw_params(struct snd_pcm_substream *substream,
				     struct snd_pcm_hw_params *hw_params)
{
	struct cs5535audio *cs5535au = snd_pcm_substream_chip(substream);
	struct cs5535audio_dma *dma = substream->runtime->private_data;
	int err;

	err = snd_pcm_lib_malloc_pages(substream,
					params_buffer_bytes(hw_params));
	if (err < 0)
		return err;
	dma->buf_addr = substream->runtime->dma_addr;
	dma->buf_bytes = params_buffer_bytes(hw_params);

	err = cs5535audio_build_dma_packets(cs5535au, dma, substream,
					    params_periods(hw_params),
					    params_period_bytes(hw_params));
	return err;
}

/*
 * hw_params - allocate the buffer and set up buffer descriptors
 */
static int snd_atiixp_pcm_hw_params(snd_pcm_substream_t *substream,
                                    snd_pcm_hw_params_t *hw_params)
{
    atiixp_t *chip = snd_pcm_substream_chip(substream);
    atiixp_dma_t *dma = (atiixp_dma_t *)substream->runtime->private_data;
    int err;

    err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
    if (err < 0)
        return err;
    dma->buf_addr = substream->runtime->dma_addr;
    dma->buf_bytes = params_buffer_bytes(hw_params);

    err = atiixp_build_dma_packets(chip, dma, substream,
                                   params_periods(hw_params),
                                   params_period_bytes(hw_params));
    if (err < 0)
        return err;

    if (dma->ac97_pcm_type >= 0) {
        struct ac97_pcm *pcm = chip->pcms[dma->ac97_pcm_type];
        /* PCM is bound to AC97 codec(s)
         * set up the AC97 codecs
         */
        if (dma->pcm_open_flag) {
            snd_ac97_pcm_close(pcm);
            dma->pcm_open_flag = 0;
        }
        err = snd_ac97_pcm_open(pcm, params_rate(hw_params),
                                params_channels(hw_params),
                                pcm->r[0].slots);
        if (err >= 0)
            dma->pcm_open_flag = 1;
    }

    return err;
}

static int s3c_idma_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct lpam_i2s_pdata *prtd = substream->runtime->private_data;

	pr_debug("Entered %s\n", __func__);

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	runtime->dma_bytes = params_buffer_bytes(params);
	memset(runtime->dma_area, 0, runtime->dma_bytes);

	prtd->start = prtd->pos = runtime->dma_addr;
	prtd->period = params_periods(params);
	prtd->periodsz = params_period_bytes(params);
	prtd->end = LP_TXBUFF_ADDR + runtime->dma_bytes;

	s3c_idma_setcallbk(substream, s3c_idma_done);

	pr_info("[email protected]%x Total=%dbytes PrdSz=%d #Prds=%d dma_area=0x%x\n",
			prtd->start, runtime->dma_bytes, prtd->periodsz,
			prtd->period, (unsigned int)runtime->dma_area);
	return 0;
}

//.........这里部分代码省略.........
#else
	printk("Error: S3C2450 I2S configration \n",);
#endif

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		rtd->dai->cpu_dai->dma_data = &s3c24xx_i2s_pcm_stereo_out;
	} else {
		rtd->dai->cpu_dai->dma_data = &s3c24xx_i2s_pcm_stereo_in;
	}

	/* Working copies of registers */
	iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
	iisfcon = readl(s3c24xx_i2s.regs + S3C2443_IISFIC);

	iiscon |= S3C_IIS0CON_TXDMACTIVE;
	iiscon |= S3C_IIS0CON_RXDMACTIVE;

	iismod &= ~S3C_IIS0MOD_CLK_MASK;
	iismod |= S3C_IIS0MOD_IMS_EXTERNAL_MASTER| S3C_IIS0MOD_INTERNAL_CLK;
	iismod &= ~S3C_IIS0MOD_MODE_MASK;
	iismod |= S3C_IIS0MOD_TXRXMODE;

	/* Multi channel enable */
	iismod &= ~S3C_IIS0MOD_DCE_MASK;
	switch (params_channels(params)) {
	case 6:
		printk("s3c i2s: 5.1channel\n");
		iismod |= S3C_IIS0MOD_DCE_SD1;
		iismod |= S3C_IIS0MOD_DCE_SD2;
		break;
	case 4:
		printk("s3c i2s: 4 channel\n");
		iismod |= S3C_IIS0MOD_DCE_SD1;
		break;
	case 2:
		printk("s3c i2s: 2 channel\n");
		break;
	default:
		printk(KERN_ERR "s3c-i2s-v40: %d channels unsupported\n",
		       params_channels(params));
		return -EINVAL;
	}

	/* Set the bit rate */
#if 0
	iismod &= ~0x6000;
#endif
	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		iismod |= S3C_IIS0MOD_8BIT;
		iismod &= ~S3C_IIS0MOD_BFS_MASK;
		iismod |= S3C_IIS0MOD_32FS;
		iismod &= ~S3C_IIS0MOD_FS_MASK;
		iismod |= S3C_IIS0MOD_384FS;
		break;
	case SNDRV_PCM_FORMAT_S16_LE:
		iismod &= ~S3C_IIS0MOD_FS_MASK;
		iismod &= ~S3C_IIS0MOD_BFS_MASK;
		iismod |= S3C_IIS0MOD_384FS | S3C_IIS0MOD_32FS;
		iismod &= ~S3C_IIS0MOD_BLC_MASK;
		iismod |= S3C_IIS0MOD_16BIT;
		break;
	case SNDRV_PCM_FORMAT_S24_LE:
		iismod &= ~S3C_IIS0MOD_FS_MASK;
		iismod &= ~S3C_IIS0MOD_BFS_MASK;
		iismod |= S3C_IIS0MOD_384FS | S3C_IIS0MOD_48FS;
		iismod &= ~S3C_IIS0MOD_BLC_MASK;
		iismod |= S3C_IIS0MOD_24BIT;
		break;
	default:
		return -EINVAL;
	}


	iisfcon |= S3C_IIS_TX_FLUSH;
	iisfcon |= S3C_IIS_RX_FLUSH;

	writel(iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	iismod &= ~S3C_IIS0MOD_FM_MASK;
	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	writel(iisfcon, s3c24xx_i2s.regs + S3C2443_IISFIC);

	/* Tx, Rx fifo flush bit clear */
	iisfcon  &= ~(S3C_IIS_TX_FLUSH | S3C_IIS_RX_FLUSH);
	writel(iisfcon, s3c24xx_i2s.regs + S3C2443_IISFIC);

	s3cdbg("s3c iis mode: 0x%08x\n", readl(s3c24xx_i2s.regs + S3C2410_IISMOD));
	s3cdbg("s3c: params_channels %d\n", params_channels(params));
	s3cdbg("s3c: params_format %d\n", params_format(params));
	s3cdbg("s3c: params_subformat %d\n", params_subformat(params));
	s3cdbg("s3c: params_period_size %d\n", params_period_size(params));
	s3cdbg("s3c: params_period_bytes %d\n", params_period_bytes(params));
	s3cdbg("s3c: params_periods %d\n", params_periods(params));
	s3cdbg("s3c: params_buffer_size %d\n", params_buffer_size(params));
	s3cdbg("s3c: params_buffer_bytes %d\n", params_buffer_bytes(params));
	s3cdbg("s3c: params_tick_time %d\n", params_tick_time(params));

	return 0;
}