[RFC,v1,0/2] iio: adc: meson: add MPLL clock workaround for GXLX

Message

Martin Blumenstingl Dec. 31, 2024, 7:42 p.m. UTC

Hello,

Amlogic GXLX SoCs seem to be mostly the same silicon as GXL. The only
known differences are:
- one less Mali-450 GPU core
- no VP9 codec
- and an odd one: the three MPLL clocks need a bit toggled in the SAR
  ADC register space

This series attempt to fix audio output (which relies on the MPLL
clocks) on the GXLX boards. Unfortunately all we have is a downstream
commit [0] without any further explanation (or anyone who wants to
provide details on this). Since it's not clear if this is a gate, a
reset or some other hardware fix: the driver side includes a warning
for users to update their .dtb along with kernel images in case we
ever figure out what these bits do and how to model them properly.


[0] https://github.com/khadas/linux/commit/d1d98f2ed8c83eb42af8880ed8e206aa402dd70a#diff-c5aaf54323ef93777c5083de37f933058ea8d0af79a1941e0b5a0667dc0f89b3


Martin Blumenstingl (2):
  dt-bindings: iio: adc: amlogic,meson-saradc: Add GXLX SoC compatible
  iio: adc: meson: add support for the GXLX SoC

 .../iio/adc/amlogic,meson-saradc.yaml         |  1 +
 drivers/iio/adc/meson_saradc.c                | 34 +++++++++++++++++++
 2 files changed, 35 insertions(+)

Comments

Neil Armstrong Jan. 2, 2025, 9:40 a.m. UTC | #1

On 31/12/2024 20:42, Martin Blumenstingl wrote:
> Hello,
> 
> Amlogic GXLX SoCs seem to be mostly the same silicon as GXL. The only
> known differences are:
> - one less Mali-450 GPU core
> - no VP9 codec
> - and an odd one: the three MPLL clocks need a bit toggled in the SAR
>    ADC register space
> 
> This series attempt to fix audio output (which relies on the MPLL
> clocks) on the GXLX boards. Unfortunately all we have is a downstream
> commit [0] without any further explanation (or anyone who wants to
> provide details on this). Since it's not clear if this is a gate, a
> reset or some other hardware fix: the driver side includes a warning
> for users to update their .dtb along with kernel images in case we
> ever figure out what these bits do and how to model them properly.
> 
> 
> [0] https://github.com/khadas/linux/commit/d1d98f2ed8c83eb42af8880ed8e206aa402dd70a#diff-c5aaf54323ef93777c5083de37f933058ea8d0af79a1941e0b5a0667dc0f89b3
> 
> 
> Martin Blumenstingl (2):
>    dt-bindings: iio: adc: amlogic,meson-saradc: Add GXLX SoC compatible
>    iio: adc: meson: add support for the GXLX SoC
> 
>   .../iio/adc/amlogic,meson-saradc.yaml         |  1 +
>   drivers/iio/adc/meson_saradc.c                | 34 +++++++++++++++++++
>   2 files changed, 35 insertions(+)
> 

LGTM

Reviewed-by: Neil Armstrong <[e-mail]>