Re: [PATCH 1/6] dt-bindings: mfd: Add ST Multi-Function eXpander driver

From: Amelie DELAUNAY
Date: Thu Feb 22 2018 - 10:20:21 EST




On 02/22/2018 02:11 PM, Linus Walleij wrote:
> On Thu, Feb 8, 2018 at 3:27 PM, Amelie Delaunay <amelie.delaunay@xxxxxx> wrote:
>
>> +Required properties:
>> +- compatible: must be "st,mfx"
>
> I bet this should be more specific. Tomorrow there will be a new
> version of this expander and then we will wish that we used
> a more specific compatible for the first one.
>
> Does this chip have any kind of product number on it?
>
> Else I would be tempted to use the compatible "st,mfx-0000"
> or something, indicating it is the first of its kind.
>

This chip has a FW version. So, I agree, I should use a compatible that
reflects this FW version.

>> +- reg: I2C address of the device
>> +- interrupts: interrupt triggered by MFX_IRQ_OUT signal
>> +- interrupt-parent: interrupt controller MFX is connected to
>> +- interrupt-controller: marks the device as an interrupt controller
>> +- #interrupt-cells: should be <1>, index of the interrupt within the
>> + controller, in accordance with the "one cell" variant of
>> + <devicetree/bindings/interrupt-controller/interrupt.txt>
>
> Seems fine.
>
>> +Optional nodes:
>> +
>> +* GPIO eXpander
>> +MFX provides 16 programmable GPIOs, and it is also possible to recover 8
>> +alternate GPIOs if the main functions are not used (touchscreen controller and
>> +IDD measurement not enabled).
>
> Apparenly Rob thinks this should go elsewhere.
>

It would go with gpio/pinctrl driver, so in dt-bindings/(gpio|pinctrl).

Regards,
Amelie

>> +- gpio-controller: marks the device node as a GPIO controller
>> +- #gpio-cells: should be <2>, the first cell is the GPIO offset on this GPIO
>> + controller, the second cell is the gpio flags in accordance with
>> + <dt-bindings/gpio/st-mfx-gpio.h>.
>
> Let's discuss these extra GPIO flag bindings separately.
>
> Yours,
> Linus Walleij
>