Re: gc2145 camera driver (front camera on PinePhone)

[Andrey Skvortsov <andrej.skvortzov@gmail.com>]

Hi Alain,

> we are also using the GC2145 sensor but in a CSI based environment.
> 
> We are in contact with GalaxyCore and following discussions we had with them
> and data they provided us with, we've made a driver for that, supporting for
> the time being 3 different resolutions via the CSI interface.
> 
> The driver is available on the STMicroelectronics STM32 github [1].
> 
> If you are ok with that, we could go further upstreaming it while testing/adding
> features necessary for the PinePhone.
> 
> [1] https://github.com/STMicroelectronics/linux/blob/v5.15-stm32mp/drivers/media/i2c/gc2145.c

I've implemented basic parallel bus support to check your driver [1] on
the PinePhone. My changes are here [2].
With your driver results are much better in compare to Megi's
driver (I'm still glad, that Megi has written one). See pictures for
comparison here [3]. Access to vendor support and (probably)
documentation gives great results.

I'd recommend to replace more of hard-coded parts of initialization
sequences with functions like in proposed Megi's driver. So this will
be clearer what different register values mean. Since you have access
to support channel/documentation it'd be easier for you to do.

It'd be nice to have at least some gc2145 driver in mainline. Do you
still have plans/time to mainline driver?

P.S.
Alain, I don't see your address in the list of recipients of last Pavel's
response. In case you have not received it, it's here [4].

1. https://github.com/STMicroelectronics/linux/blob/v6.1-stm32mp/drivers/media/i2c/gc2145.c
2. https://github.com/AndreySV/linux/commit/f06ff60eb7a664dcafa8d40901a1ab0f59071529
3. https://github.com/AndreySV/linux/issues/1
4. https://lwn.net/ml/linux-kernel/Y6tGfxrq/Mh1JoA9@duo.ucw.cz
-- 
Best regards,
Andrey Skvortsov