Subject: Re: [PATCH] [v2] at86rf230: convert to gpio descriptors

From: Dmitry Torokhov <[email-masked]>
Date: Wed, 1 Feb 2023 08:20:57 -0800

Hi Miquel,

On Wed, Feb 01, 2023 at 09:33:32AM +0100, Miquel Raynal wrote:
> Hi Dmitry,
> 
> [email-masked] wrote on Tue, 31 Jan 2023 16:50:07 -0800:
> 
> > On Tue, Jan 31, 2023 at 3:52 PM Dmitry Torokhov
> > <[email-masked]> wrote:
> > >
> > > Hi Arnd,
> > >
> > > On Thu, Jan 26, 2023 at 8:32 AM Arnd Bergmann <[email-masked]> wrote:  
> > > >
> > > >         /* Reset */
> > > > -       if (gpio_is_valid(rstn)) {
> > > > +       if (rstn) {
> > > >                 udelay(1);
> > > > -               gpio_set_value_cansleep(rstn, 0);
> > > > +               gpiod_set_value_cansleep(rstn, 0);
> > > >                 udelay(1);
> > > > -               gpio_set_value_cansleep(rstn, 1);
> > > > +               gpiod_set_value_cansleep(rstn, 1);  
> > >
> > > For gpiod conversions, if we are not willing to chase whether existing
> > > DTSes specify polarities
> > > properly and create workarounds in case they are wrong, we should use
> > > gpiod_set_raw_value*()
> > > (my preference would be to do the work and not use "raw" variants).
> > >
> > > In this particular case, arch/arm/boot/dts/vf610-zii-dev-rev-c.dts
> > > defines reset line as active low,
> > > so you are leaving the device in reset state.
> 
> You mean the semantics of gpio_set_value() gpiod_set_value() are
> different? Looking at your patch it looks like gpio_set_value() asserts
> a physical line state (high or low) while gpiod_set_value() would
> actually try to assert a logical state (enabled or disabled) with the
> meaning of those being possibly inverted thanks to the DT polarities.
> Am I getting this right?

Right. If one wants to do physical levels, they need to use gpiod "raw"
APIs.

Thanks.

-- 
Dmitry