Re: [PATCH v3 09/10] gpio: bd73800: Support ROHM BD73800 PMIC GPIOs

[Matti Vaittinen <mazziesaccount@gmail.com>]

On 02/09/2026 15:39, Linus Walleij wrote:
> Hi Matti,
> 
> thanks for your patch!
> 
> On Wed, Sep 2, 2026 at 1:07 PM Matti Vaittinen
> <matti.vaittinen@linux.dev> wrote:
> 
>> From: Matti Vaittinen <mazziesaccount@gmail.com>
>>
>> The ROHM BD73800 PMIC has 4 pins (named GPIO1, CLKOUT, FAULT_B and
>> EXTEN_OUT) which might have been set to operate as a GPI or GPO when OTP
>> (One Time Programmable memory) is written at device manufacturing.
>> Support the GPI/GPO use-case via GPIO framework.
>>
>> The default OTP for these pins is to not use any of them as GPI or GPO.
>> (The GPIO1 defaults as an ADC input regardless the naming). Hence the
>> driver assumes none of these pins is a GPI/GPO unless explicitly pointed
>> as GPI or GPO via device tree.
>>
>> Furthermore, pin's direction can't be changed after OTP configuration is
>> done. Also the default drive type for a GPO (CMOS / Open Drain) is set
>> by the OTP configuration. The BD73800 has a set of undocumented test
>> registers which should allow changing the drive type. Access to the test
>> register area or the test registers aren't documented and so this driver
>> does not support configuring the drive type even though it might be
>> doable.
>>
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> 
> Pretty neat with gpio-regmap isn't it? :)

Yep. I like the added flexibility now that it has got those callbacks a 
driver can register... ;)

> Reviewed-by: Linus Walleij <linusw@kernel.org>

Thanks!

Yours,
	-- Matti

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

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