Re: [PATCH v3 2/3] mwifiex: parse chip specific gpio from device tree

Arnd Bergmann
2016-02-09T14:19:25Z

On Tuesday 09 February 2016 14:03:19 Amitkumar Karwar wrote:
>
> > On Mon, Feb 08, 2016 at 01:11:03PM +0100, Arnd Bergmann wrote:
> > > On Monday 08 February 2016 02:15:27 Amitkumar Karwar wrote:
> > > > if (adapter->dt_node) {
> > > > + if (of_property_read_u32(adapter->dt_node,
> > > > + "mwifiex,chip-
> > gpio",
> > > > + &data) == 0) {
> > > > + mwifiex_dbg(adapter, INFO,
> > > > + "chip_gpio = 0x%x\n",
> > data);
> > > > + adapter->hs_cfg.gpio = data;
> > > > + }
> > > > +
> > > >
> > >
> > > Please use the GPIO DT binding. Reading a number from DT is not a
> > > proper way to get a GPIO number, as you may have more than one GPIO
> > > controller in a system and it is not obvious to which controller this
> > > number belongs, or if you need to specify things like polarity.
> >
> > My read of this is it is not the host SOC gpio, but the WiFi device's
> > GPIO number. The host GPIO is defined in patch 3. We could still use the
> > GPIO binding to describe it doing something like "marvell,<wifi gpio pin
> > name>-gpios". Then the assignment is based on the property name.

I see.

> Yes. This is not host SOC gpio. It's wifi chip's gpio number.
> We will use GPIO binding for this in updated version.

No, if it doesn't refer to a number that is interpreted by the host
but is used internally in the device, then leave it as it is, as Rob
suggested.

Arnd