[alsa-devel] Applied "ASoC: fsl_ssi: Caculate bit clock rate using slot number and width" to the asoc tree

Mark Brown broonie at kernel.org
Tue Sep 19 15:46:51 CEST 2017


The patch

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

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From b0a7043d5c2ccdd306959f295bf1a62be025cbf5 Mon Sep 17 00:00:00 2001
From: Nicolin Chen <nicoleotsuka at gmail.com>
Date: Wed, 13 Sep 2017 20:07:09 -0700
Subject: [PATCH] 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: Nicolin Chen <nicoleotsuka at gmail.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/fsl/fsl_ssi.c | 46 ++++++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 64598d1183f8..f2f51e06e22c 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -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,
 };
-- 
2.14.1



More information about the Alsa-devel mailing list