[PATCH v1 0/3] iio: adc: meson: tune init sequence

Jonathan Cameron jic23 at kernel.org
Sun Jul 16 09:11:34 PDT 2023


On Sat, 15 Jul 2023 14:05:57 +0300
George Stark <gnstark at sberdevices.ru> wrote:

> This patch is a part of effort to support meson a1 SoC and make meson saradc driver
> independent from vendor boot code initialization in common.
> 
> Information was taken from vendor kernel 5.4, 4.19 and vendor uboot 2019.
> Most of the bits are undocumented at all or it's not said how they affect measuring.
> 
> All those bits are already initialized in bl* code and since kernel driver dosn't
> rewrite or reset any registers but only changes some bits at init stage everything
> works fine.
> 
> Test procedure is rather simple - one can change those bits in runtime
> (e.g. using devmem) and try to read channels (cat /sys/bus/platform/drivers/meson-saradc/.../iio:device0/*)
> changing some of those bits leads to measure procedure errors or abnormal results.
> Another test is build meson saradc as module, reset adc by reset bit, reload module
> and compare measure results to those got before reset.
> 
> George Stark (3):
>   iio: adc: meson: init channels 0,1 input muxes
>   iio: adc: meson: init internal continuous ring counter
>   iio: adc: meson: init voltage control bits
> 
>  drivers/iio/adc/meson_saradc.c | 73 ++++++++++++++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
> 
These look fine to me, but I'd like them to sit on list a little while
on off chance anyone else has feedback on them.

Thanks,

Jonathan





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