Re: [PATCH v2 09/10] gpio: bd73800: Support ROHM BD73800 PMIC GPIOs

[Matti Vaittinen <mazziesaccount@gmail.com>]

On 13/08/2026 11:34, Matti Vaittinen wrote:
> On 07/08/2026 23:29, Linus Walleij wrote:

...

>>   * @fixed_direction_output:
>>   *                      (Optional) Bitmap representing the fixed 
>> direction of
>>   *                      the GPIO lines. Useful when there are GPIO 
>> lines with a
>>   *                      fixed direction mixed together in the same 
>> register.
>>
>> It seems you can set up the fixed_direction_output mask from OTP
>> and just use the library, right?
> 
> The BD73800 uses different registers for 'out' and 'in'. So there aren't 
> really "GPIO lines with a fixed direction mixed together in the same 
> register".

...

> I think the BD73800 can indeed use the gpio-regmap, by keeping the pin 
> direction information in private data and adding a custom xlate, which 
> errors out if get is requested for output pin, or set is requested for 
> input. I am not sure how much of an improvement it is compared to the 
> patch v2, but I'll give it a shot :) I believe the new -rc1 isn't that 
> far away, and hopefully the gpio-regmap -stuff from the next will be in 
> it together with the regulator stuff bindings depended.

Gah. Please, ignore the erroring-out part. I don't know where I picked 
the idea that the hardware would always return '0' when reading the 
GPO_OUT register. I think this might have been something I have 
experienced on a setup where the pin was _not_ set to GPO by OTP. 
Furthermore, the xlate will never get called if user tries to set value 
for a GPI pin.

Anyways, implementing xlate with op-check allows me to support this 
PMIC, even though the register to read for pin status depends on OTP.

So yes, v3 should be able to use gpio-regmap. I will probably delay 
sending it until v7.3-rc1 is out so I get (all?) dependencies in.

Yours,
	-- Matti

-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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