diff mbox series

ASoC: wm8962: Wait for updated value of WM8962_CLOCKING1 register

Message ID 20221107063818.2468193-1-chancel.liu@nxp.com
State New
Headers
Series ASoC: wm8962: Wait for updated value of WM8962_CLOCKING1 register |

Commit Message

Chancel Liu Nov. 7, 2022, 6:38 a.m. UTC 
  DSPCLK_DIV field in WM8962_CLOCKING1 register is used to generate
correct frequency of LRCLK and BCLK. Sometimes the read-only value
can't be updated timely after enabling SYSCLK. This results in wrong
calculation values. Delay is introduced here to wait for newest value
from register. The time of the delay should be at least 500~1000us
according to test.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 sound/soc/codecs/wm8962.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Charles Keepax Nov. 7, 2022, 10:10 a.m. UTC | #1 
On Mon, Nov 07, 2022 at 02:38:18PM +0800, Chancel Liu wrote:
> DSPCLK_DIV field in WM8962_CLOCKING1 register is used to generate
> correct frequency of LRCLK and BCLK. Sometimes the read-only value
> can't be updated timely after enabling SYSCLK. This results in wrong
> calculation values. Delay is introduced here to wait for newest value
> from register. The time of the delay should be at least 500~1000us
> according to test.
> 
> Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
> ---
>  sound/soc/codecs/wm8962.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
> index b4b4355c6728..563843565f68 100644
> --- a/sound/soc/codecs/wm8962.c
> +++ b/sound/soc/codecs/wm8962.c
> @@ -2503,6 +2503,14 @@ static void wm8962_configure_bclk(struct snd_soc_component *component)
>  		snd_soc_component_update_bits(component, WM8962_CLOCKING2,
>  				WM8962_SYSCLK_ENA_MASK, WM8962_SYSCLK_ENA);
>  
> +	/* DSPCLK_DIV field in WM8962_CLOCKING1 register is used to generate
> +	 * correct frequency of LRCLK and BCLK. Sometimes the read-only value
> +	 * can't be updated timely after enabling SYSCLK. This results in wrong
> +	 * calculation values. Delay is introduced here to wait for newest
> +	 * value from register. The time of the delay should be at least
> +	 * 500~1000us according to test.
> +	 */
> +	msleep(1);

This looks reasonable but for a 1ms delay we should really be
using usleep_range rather than msleep.

Thanks,
Charles
diff mbox series

Patch

diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
index b4b4355c6728..563843565f68 100644
--- a/sound/soc/codecs/wm8962.c
+++ b/sound/soc/codecs/wm8962.c
@@ -2503,6 +2503,14 @@  static void wm8962_configure_bclk(struct snd_soc_component *component)
 		snd_soc_component_update_bits(component, WM8962_CLOCKING2,
 				WM8962_SYSCLK_ENA_MASK, WM8962_SYSCLK_ENA);
 
+	/* DSPCLK_DIV field in WM8962_CLOCKING1 register is used to generate
+	 * correct frequency of LRCLK and BCLK. Sometimes the read-only value
+	 * can't be updated timely after enabling SYSCLK. This results in wrong
+	 * calculation values. Delay is introduced here to wait for newest
+	 * value from register. The time of the delay should be at least
+	 * 500~1000us according to test.
+	 */
+	msleep(1);
 	dspclk = snd_soc_component_read(component, WM8962_CLOCKING1);
 
 	if (snd_soc_component_get_bias_level(component) != SND_SOC_BIAS_ON)