diff mbox series

ASoC: wm8960: Fix wrong bclk and lrclk with pll enabled for some chips

Message ID 1616150926-22892-1-git-send-email-shengjiu.wang@nxp.com (mailing list archive)
State Accepted
Commit 16b82e75c15a7dbd564ea3654f3feb61df9e1e6f
Headers show
Series ASoC: wm8960: Fix wrong bclk and lrclk with pll enabled for some chips | expand

Commit Message

Shengjiu Wang March 19, 2021, 10:48 a.m. UTC
The input MCLK is 12.288MHz, the desired output sysclk is 11.2896MHz
and sample rate is 44100Hz, with the configuration pllprescale=2,
postscale=sysclkdiv=1, some chip may have wrong bclk
and lrclk output with pll enabled in master mode, but with the
configuration pllprescale=1, postscale=2, the output clock is correct.

From Datasheet, the PLL performs best when f2 is between
90MHz and 100MHz when the desired sysclk output is 11.2896MHz
or 12.288MHz, so sysclkdiv = 2 (f2/8) is the best choice.

So search available sysclk_divs from 2 to 1 other than from 1 to 2.

Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/codecs/wm8960.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Charles Keepax March 23, 2021, 9:59 a.m. UTC | #1
On Fri, Mar 19, 2021 at 06:48:46PM +0800, Shengjiu Wang wrote:
> The input MCLK is 12.288MHz, the desired output sysclk is 11.2896MHz
> and sample rate is 44100Hz, with the configuration pllprescale=2,
> postscale=sysclkdiv=1, some chip may have wrong bclk
> and lrclk output with pll enabled in master mode, but with the
> configuration pllprescale=1, postscale=2, the output clock is correct.
> 
> >From Datasheet, the PLL performs best when f2 is between
> 90MHz and 100MHz when the desired sysclk output is 11.2896MHz
> or 12.288MHz, so sysclkdiv = 2 (f2/8) is the best choice.
> 
> So search available sysclk_divs from 2 to 1 other than from 1 to 2.
> 
> Fixes: 84fdc00d519f ("ASoC: codec: wm9860: Refactor PLL out freq search")
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles
Mark Brown March 23, 2021, 10:12 p.m. UTC | #2
On Fri, 19 Mar 2021 18:48:46 +0800, Shengjiu Wang wrote:
> The input MCLK is 12.288MHz, the desired output sysclk is 11.2896MHz
> and sample rate is 44100Hz, with the configuration pllprescale=2,
> postscale=sysclkdiv=1, some chip may have wrong bclk
> and lrclk output with pll enabled in master mode, but with the
> configuration pllprescale=1, postscale=2, the output clock is correct.
> 
> >From Datasheet, the PLL performs best when f2 is between
> 90MHz and 100MHz when the desired sysclk output is 11.2896MHz
> or 12.288MHz, so sysclkdiv = 2 (f2/8) is the best choice.
> 
> [...]

Applied to

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

Thanks!

[1/1] ASoC: wm8960: Fix wrong bclk and lrclk with pll enabled for some chips
      commit: 16b82e75c15a7dbd564ea3654f3feb61df9e1e6f

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.

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Thanks,
Mark
diff mbox series

Patch

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index df351519a3a6..cda9cd935d4f 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -707,7 +707,13 @@  int wm8960_configure_pll(struct snd_soc_component *component, int freq_in,
 	best_freq_out = -EINVAL;
 	*sysclk_idx = *dac_idx = *bclk_idx = -1;
 
-	for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+	/*
+	 * From Datasheet, the PLL performs best when f2 is between
+	 * 90MHz and 100MHz, the desired sysclk output is 11.2896MHz
+	 * or 12.288MHz, then sysclkdiv = 2 is the best choice.
+	 * So search sysclk_divs from 2 to 1 other than from 1 to 2.
+	 */
+	for (i = ARRAY_SIZE(sysclk_divs) - 1; i >= 0; --i) {
 		if (sysclk_divs[i] == -1)
 			continue;
 		for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {