Re: [PATCH 1/2] dt-bindings: pinctrl: airoha: Add EN7581 pinctrl controller

[Benjamin Larsson <benjamin.larsson@genexis.eu>]

On 18/08/2024 18:02, Andrew Lunn wrote:
>>
>> Hi, per my understanding there is no public datasheet/register reference
>> manual.
>>
>> But here is the division of regions of the registers in the gpio block and
>> how it is currently divided between the drivers (according to my current
>> understanding).
>>
>> 1FBF0200, gpio/pinctrl
>> 1FBF0204, gpio/pinctrl
>> 1FBF0208, gpio/pinctrl
>> 1FBF020C, gpio/pinctrl
>> 1FBF0210, gpio/pinctrl
>> 1FBF0214, gpio/pinctrl
> A typical SoC has multiple instances of a GPIO controller. Each GPIO
> controller typically has 4 or 5 registers: In, Out, Direction,
> Interrupt Enable, Interrupt Status. If these 4 or 5 registers are
> contiguous, you could have one DT node per controller, rather than one
> node for all GPIO controllers.
>
> If the hardware designer has really messed up and fully interleaved
> GPIO and PWM, it might be better to have an MFD. The MFD node has a
> single reg covering the entire range. The MFD would then map the whole
> range, and provide accessors to the child devices. Hard code the
> knowledge of what registers are where. Given how badly the hardware is
> designed, it is unlikely it will get reused in the future, so there is
> no point putting lots of stuff into DT. Hard code it.
>
> 	Andrew

Hi, the pwm driver could be re-used on the EN7523 SoC. Future Airoha 
SoCs will most likely have the same ip-block also.

MvH

Benjamin Larsson