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Commit c3ecef21 authored by Zidan Wang's avatar Zidan Wang Committed by Mark Brown
Browse files

ASoC: fsl_sai: add sai master mode support 



When sai works on master mode, set its bit clock and frame clock.

SAI has 4 MCLK source, bus clock, MCLK1, MCLK2 and MCLK3. fsl_sai_set_bclk
will select proper MCLK source, then calculate and set the bit clock divider.

After fsl_sai_set_bclk, enable the selected mclk in hw_params(), and add
hw_free() to disable the mclk.

Signed-off-by: default avatarZidan Wang <zidan.wang@freescale.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b787f68c

sound/soc/fsl/fsl_sai.c

+114 −3
Original line number Diff line number Diff line 
/*

 * Freescale ALSA SoC Digital Audio Interface (SAI) driver.

 *

 * Copyright 2012-2013 Freescale Semiconductor, Inc.

 * Copyright 2012-2015 Freescale Semiconductor, Inc.

 *

 * This program is free software, you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the
@@ -251,12 +251,14 @@ static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai, 
		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;

		break;

	case SND_SOC_DAIFMT_CBM_CFM:

		sai->is_slave_mode = true;

		break;

	case SND_SOC_DAIFMT_CBS_CFM:

		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;

		break;

	case SND_SOC_DAIFMT_CBM_CFS:

		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;

		sai->is_slave_mode = true;

		break;

	default:

		return -EINVAL;
@@ -288,6 +290,79 @@ static int fsl_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt) 
	return ret;

}



static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)

{

	struct fsl_sai *sai = snd_soc_dai_get_drvdata(dai);

	unsigned long clk_rate;

	u32 savediv = 0, ratio, savesub = freq;

	u32 id;

	int ret = 0;



	/* Don't apply to slave mode */

	if (sai->is_slave_mode)

		return 0;



	for (id = 0; id < FSL_SAI_MCLK_MAX; id++) {

		clk_rate = clk_get_rate(sai->mclk_clk[id]);

		if (!clk_rate)

			continue;



		ratio = clk_rate / freq;



		ret = clk_rate - ratio * freq;



		/*

		 * Drop the source that can not be

		 * divided into the required rate.

		 */

		if (ret != 0 && clk_rate / ret < 1000)

			continue;



		dev_dbg(dai->dev,

			"ratio %d for freq %dHz based on clock %ldHz\n",

			ratio, freq, clk_rate);



		if (ratio % 2 == 0 && ratio >= 2 && ratio <= 512)

			ratio /= 2;

		else

			continue;



		if (ret < savesub) {

			savediv = ratio;

			sai->mclk_id[tx] = id;

			savesub = ret;

		}



		if (ret == 0)

			break;

	}



	if (savediv == 0) {

		dev_err(dai->dev, "failed to derive required %cx rate: %d\n",

				tx ? 'T' : 'R', freq);

		return -EINVAL;

	}



	if ((tx && sai->synchronous[TX]) || (!tx && !sai->synchronous[RX])) {

		regmap_update_bits(sai->regmap, FSL_SAI_RCR2,

				   FSL_SAI_CR2_MSEL_MASK,

				   FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));

		regmap_update_bits(sai->regmap, FSL_SAI_RCR2,

				   FSL_SAI_CR2_DIV_MASK, savediv - 1);

	} else {

		regmap_update_bits(sai->regmap, FSL_SAI_TCR2,

				   FSL_SAI_CR2_MSEL_MASK,

				   FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));

		regmap_update_bits(sai->regmap, FSL_SAI_TCR2,

				   FSL_SAI_CR2_DIV_MASK, savediv - 1);

	}



	dev_dbg(dai->dev, "best fit: clock id=%d, div=%d, deviation =%d\n",

			sai->mclk_id[tx], savediv, savesub);



	return 0;

}



static int fsl_sai_hw_params(struct snd_pcm_substream *substream,

		struct snd_pcm_hw_params *params,

		struct snd_soc_dai *cpu_dai)
@@ -297,6 +372,24 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream, 
	unsigned int channels = params_channels(params);

	u32 word_width = snd_pcm_format_width(params_format(params));

	u32 val_cr4 = 0, val_cr5 = 0;

	int ret;



	if (!sai->is_slave_mode) {

		ret = fsl_sai_set_bclk(cpu_dai, tx,

			2 * word_width * params_rate(params));

		if (ret)

			return ret;



		/* Do not enable the clock if it is already enabled */

		if (!(sai->mclk_streams & BIT(substream->stream))) {

			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[tx]]);

			if (ret)

				return ret;



			sai->mclk_streams |= BIT(substream->stream);

		}



	}



	if (!sai->is_dsp_mode)

		val_cr4 |= FSL_SAI_CR4_SYWD(word_width);
@@ -322,6 +415,22 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream, 
	return 0;

}



static int fsl_sai_hw_free(struct snd_pcm_substream *substream,

		struct snd_soc_dai *cpu_dai)

{

	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);

	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;



	if (!sai->is_slave_mode &&

			sai->mclk_streams & BIT(substream->stream)) {

		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[tx]]);

		sai->mclk_streams &= ~BIT(substream->stream);

	}



	return 0;

}





static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,

		struct snd_soc_dai *cpu_dai)

{
@@ -428,6 +537,7 @@ static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = { 
	.set_sysclk	= fsl_sai_set_dai_sysclk,

	.set_fmt	= fsl_sai_set_dai_fmt,

	.hw_params	= fsl_sai_hw_params,

	.hw_free	= fsl_sai_hw_free,

	.trigger	= fsl_sai_trigger,

	.startup	= fsl_sai_startup,

	.shutdown	= fsl_sai_shutdown,
@@ -600,8 +710,9 @@ static int fsl_sai_probe(struct platform_device *pdev) 
		sai->bus_clk = NULL;

	}



	for (i = 0; i < FSL_SAI_MCLK_MAX; i++) {

		sprintf(tmp, "mclk%d", i + 1);

	sai->mclk_clk[0] = sai->bus_clk;

	for (i = 1; i < FSL_SAI_MCLK_MAX; i++) {

		sprintf(tmp, "mclk%d", i);

		sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);

		if (IS_ERR(sai->mclk_clk[i])) {

			dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",

sound/soc/fsl/fsl_sai.h

+7 −2
Original line number Diff line number Diff line
@@ -72,13 +72,15 @@ 


/* SAI Transmit and Recieve Configuration 2 Register */

#define FSL_SAI_CR2_SYNC	BIT(30)

#define FSL_SAI_CR2_MSEL_MASK	(0xff << 26)

#define FSL_SAI_CR2_MSEL_MASK	(0x3 << 26)

#define FSL_SAI_CR2_MSEL_BUS	0

#define FSL_SAI_CR2_MSEL_MCLK1	BIT(26)

#define FSL_SAI_CR2_MSEL_MCLK2	BIT(27)

#define FSL_SAI_CR2_MSEL_MCLK3	(BIT(26) | BIT(27))

#define FSL_SAI_CR2_MSEL(ID)	((ID) << 26)

#define FSL_SAI_CR2_BCP		BIT(25)

#define FSL_SAI_CR2_BCD_MSTR	BIT(24)

#define FSL_SAI_CR2_DIV_MASK	0xff



/* SAI Transmit and Recieve Configuration 3 Register */

#define FSL_SAI_CR3_TRCE	BIT(16)
@@ -120,7 +122,7 @@ 
#define FSL_SAI_CLK_MAST2	2

#define FSL_SAI_CLK_MAST3	3



#define FSL_SAI_MCLK_MAX	3

#define FSL_SAI_MCLK_MAX	4



/* SAI data transfer numbers per DMA request */

#define FSL_SAI_MAXBURST_TX 6
@@ -132,11 +134,14 @@ struct fsl_sai { 
	struct clk *bus_clk;

	struct clk *mclk_clk[FSL_SAI_MCLK_MAX];



	bool is_slave_mode;

	bool is_lsb_first;

	bool is_dsp_mode;

	bool sai_on_imx;

	bool synchronous[2];



	unsigned int mclk_id[2];

	unsigned int mclk_streams;

	struct snd_dmaengine_dai_dma_data dma_params_rx;

	struct snd_dmaengine_dai_dma_data dma_params_tx;

};