Commit b0a7043d authored by Nicolin Chen's avatar Nicolin Chen Committed by Mark Brown
Browse files

ASoC: fsl_ssi: Caculate bit clock rate using slot number and width 



The set_sysclk() now is used to override the output bit clock rate.
But this is not a common way to implement a set_dai_sysclk(). And
this creates a problem when a general machine driver (simple-card
for example) tries to do set_dai_sysclk() by passing an input clock
rate for the baud clock instead of setting the bit clock rate as
fsl_ssi driver expected.

So this patch solves this problem by firstly removing set_sysclk()
since the hw_params() can calculate the bit clock rate. Secondly,
in order not to break those TDM use cases which previously might
have been using set_sysclk() to override the bit clock rate, this
patch changes the driver to calculate the bit clock rate using the
slot number and the slot width from the via set_tdm_slot().

The patch also removes an obsolete comment of the dir parameter.

Signed-off-by: default avatarNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 2db5f9e9

sound/soc/fsl/fsl_ssi.c

+26 −20
Original line number Diff line number Diff line
@@ -197,12 +197,13 @@ struct fsl_ssi_soc_data { 
 * @use_dma: DMA is used or FIQ with stream filter

 * @use_dual_fifo: DMA with support for both FIFOs used

 * @fifo_deph: Depth of the SSI FIFOs

 * @slot_width: width of each DAI slot

 * @slots: number of slots

 * @rxtx_reg_val: Specific register settings for receive/transmit configuration

 *

 * @clk: SSI clock

 * @baudclk: SSI baud clock for master mode

 * @baudclk_streams: Active streams that are using baudclk

 * @bitclk_freq: bitclock frequency set by .set_dai_sysclk

 *

 * @dma_params_tx: DMA transmit parameters

 * @dma_params_rx: DMA receive parameters
@@ -233,12 +234,13 @@ struct fsl_ssi_private { 
	bool use_dual_fifo;

	bool has_ipg_clk_name;

	unsigned int fifo_depth;

	unsigned int slot_width;

	unsigned int slots;

	struct fsl_ssi_rxtx_reg_val rxtx_reg_val;



	struct clk *clk;

	struct clk *baudclk;

	unsigned int baudclk_streams;

	unsigned int bitclk_freq;



	/* regcache for volatile regs */

	u32 regcache_sfcsr;
@@ -700,8 +702,8 @@ static void fsl_ssi_shutdown(struct snd_pcm_substream *substream, 
 * Note: This function can be only called when using SSI as DAI master

 *

 * Quick instruction for parameters:

 * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels

 * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK.

 * freq: Output BCLK frequency = samplerate * slots * slot_width

 *       (In 2-channel I2S Master mode, slot_width is fixed 32)

 */

static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,

		struct snd_soc_dai *cpu_dai,
@@ -712,15 +714,21 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream, 
	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret;

	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;

	unsigned long clkrate, baudrate, tmprate;

	unsigned int slots = params_channels(hw_params);

	unsigned int slot_width = 32;

	u64 sub, savesub = 100000;

	unsigned int freq;

	bool baudclk_is_used;



	/* Prefer the explicitly set bitclock frequency */

	if (ssi_private->bitclk_freq)

		freq = ssi_private->bitclk_freq;

	else

		freq = params_channels(hw_params) * 32 * params_rate(hw_params);

	/* Override slots and slot_width if being specifically set... */

	if (ssi_private->slots)

		slots = ssi_private->slots;

	/* ...but keep 32 bits if slots is 2 -- I2S Master mode */

	if (ssi_private->slot_width && slots != 2)

		slot_width = ssi_private->slot_width;



	/* Generate bit clock based on the slot number and slot width */

	freq = slots * slot_width * params_rate(hw_params);



	/* Don't apply it to any non-baudclk circumstance */

	if (IS_ERR(ssi_private->baudclk))
@@ -805,16 +813,6 @@ static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream, 
	return 0;

}



static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,

		int clk_id, unsigned int freq, int dir)

{

	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);



	ssi_private->bitclk_freq = freq;



	return 0;

}



/**

 * fsl_ssi_hw_params - program the sample size

 *
@@ -1095,6 +1093,12 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask, 
	struct regmap *regs = ssi_private->regs;

	u32 val;



	/* The word length should be 8, 10, 12, 16, 18, 20, 22 or 24 */

	if (slot_width & 1 || slot_width < 8 || slot_width > 24) {

		dev_err(cpu_dai->dev, "invalid slot width: %d\n", slot_width);

		return -EINVAL;

	}



	/* The slot number should be >= 2 if using Network mode or I2S mode */

	regmap_read(regs, CCSR_SSI_SCR, &val);

	val &= CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_NET;
@@ -1121,6 +1125,9 @@ static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask, 


	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN, val);



	ssi_private->slot_width = slot_width;

	ssi_private->slots = slots;



	return 0;

}
@@ -1191,7 +1198,6 @@ static const struct snd_soc_dai_ops fsl_ssi_dai_ops = { 
	.hw_params	= fsl_ssi_hw_params,

	.hw_free	= fsl_ssi_hw_free,

	.set_fmt	= fsl_ssi_set_dai_fmt,

	.set_sysclk	= fsl_ssi_set_dai_sysclk,

	.set_tdm_slot	= fsl_ssi_set_dai_tdm_slot,

	.trigger	= fsl_ssi_trigger,

};

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