ASoC: max9867: Implement exact integer mode

Commit Message

Pavel Dobias Nov. 23, 2022, 3:38 p.m. UTC

For 8kHz and 16kHz sample rates and certain PCLK values
the codec can be programmed to operate in exact integer
mode. If available, use it to achieve the exact sample rate.

Signed-off-by: Pavel Dobias <[e-mail]>
---
 sound/soc/codecs/max9867.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

Comments

Mark Brown Nov. 28, 2022, 4:39 p.m. UTC | #1

On Wed, 23 Nov 2022 16:38:18 +0100, Pavel Dobias wrote:
> For 8kHz and 16kHz sample rates and certain PCLK values
> the codec can be programmed to operate in exact integer
> mode. If available, use it to achieve the exact sample rate.
> 
> 

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: max9867: Implement exact integer mode
      commit: 082d3c998c7b5ee91472c12d2d7dc59d4d1ddec6

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

Patch

diff --git a/sound/soc/codecs/max9867.c b/sound/soc/codecs/max9867.c
index 6d2941a9dbd6..e161ab037bf7 100644
--- a/sound/soc/codecs/max9867.c
+++ b/sound/soc/codecs/max9867.c
@@ -323,7 +323,7 @@  static int max9867_startup(struct snd_pcm_substream *substream,
 static int max9867_dai_hw_params(struct snd_pcm_substream *substream,
 		struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
 {
-	int value;
+	int value, freq = 0;
 	unsigned long int rate, ratio;
 	struct snd_soc_component *component = dai->component;
 	struct max9867_priv *max9867 = snd_soc_component_get_drvdata(component);
@@ -373,6 +373,35 @@  static int max9867_dai_hw_params(struct snd_pcm_substream *substream,
 		}
 		regmap_update_bits(max9867->regmap, MAX9867_IFC1B,
 			MAX9867_IFC1B_BCLK_MASK, value);
+
+		/* Exact integer mode available for 8kHz and 16kHz sample rates
+		 * and certain PCLK (prescaled MCLK) values.
+		 */
+		if (params_rate(params) == 8000 ||
+		    params_rate(params) == 16000) {
+			switch (max9867->pclk) {
+			case 12000000:
+				freq = 0x08;
+				break;
+			case 13000000:
+				freq = 0x0A;
+				break;
+			case 16000000:
+				freq = 0x0C;
+				break;
+			case 19200000:
+				freq = 0x0E;
+				break;
+			}
+		}
+		if (freq && params_rate(params) == 16000)
+			freq++;
+
+		/* If exact integer mode not available, the freq value
+		 * remains zero, i.e. normal mode is used.
+		 */
+		regmap_update_bits(max9867->regmap, MAX9867_SYSCLK,
+				   MAX9867_FREQ_MASK, freq);
 	} else {
 		/*
 		 * digital pll locks on to any externally supplied LRCLK signal
@@ -428,8 +457,6 @@  static int max9867_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 			 freq);
 	max9867->sysclk = freq;
 	value = value << MAX9867_PSCLK_SHIFT;
-	/* exact integer mode is not supported */
-	value &= ~MAX9867_FREQ_MASK;
 	regmap_update_bits(max9867->regmap, MAX9867_SYSCLK,
 			MAX9867_PSCLK_MASK, value);
 	return 0;