Re: [PATCH v4 09/10] gpio: bd73800: Support ROHM BD73800 PMIC GPIOs

[Matti Vaittinen <mazziesaccount@gmail.com>]

On 16/09/2026 20:31, Linus Walleij wrote:
> On Wed, Sep 16, 2026 at 8:12 AM 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>
>> Acked-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> 
> Looks really nice now!
> Reviewed-by: Linus Walleij <linusw@kernel.org>

Sorry Linus! I dropped your tag from v3 by mistake. I hope you didn't 
waste too much time re-reviewing this :( Well, thanks anyways and again!

Yours,
	-- Matti.

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

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