Re: [PATCH v1 3/3] leds: aat1290: Add support for AAT1270 Current Regulator for Flash LEDs

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

On 10/8/26 10:15 AM, Svyatoslav Ryhel wrote:
> ср, 7 жовт. 2026 р. о 22:04 Jacek Anaszewski <jacek.anaszewski@gmail.com> пише:
>>
>> Hi Svyatoslav,
>>
>> On 10/7/26 10:54 AM, Svyatoslav Ryhel wrote:
>>> The AAT1270 is quite similar to the AAT1290, but it does not support the
>>> Advanced Simple Serial Control (AS2C) used in the AAT1290. The AAT1270
>>> uses an earlier version of AS2C, namely Simple Serial Control, which lacks
>>> address-sending capabilities.
>>
>> It seems that it is not possible to set brightness level and flash
>> timeout. Those values are controlled by the values of RSET and CT
>> elements attached to the controller.
> 
> This is not entirely true. S2C allows setting brightness level
> perfectly fine, I have tested it on my LG Optimus 2X P990 (star) that
> has this LED flash driver. Flash timeout is fixed, that is true, but
> both AAT1270 and AAT1290 feature mandatory flash inhibit logic which
> is not implemented by this driver and can be used to set emergency
> flash disable.
OK, let me try to perform more thorough review, after consulting data
sheet, in the coming days.

>> Those values should be conveyed
>> via Device Tree, and the LED device API should reflect that accordingly.
>>
> 
> They are calculated same way as AAT1290 does and set in the device
> tree. Being fixed does not mean they should be removed. Device tree
> describes hardware and those values are part of hw description.
> 
>> The question is whether it is worth a hassle to add support for this
>> older chipset version. Could you let as know on which device it is
>> present.
>>
> 
> LG Optimus 2X P990 (star). It is a Tegra smartphone, it is not yet
> supported by mainline Linux kernel, but it will be in near future. I
> am currently upstreaming missing parts for better support.

Ack.

-- 
Best regards,
Jacek Anaszewski