Re: [PATCH v4 7/9] serial: sc16is7xx: fix regression with GPIO configuration

From: Hugo Villeneuve
Date: Wed May 31 2023 - 10:20:53 EST


On Wed, 31 May 2023 00:56:57 +0300
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:

> On Tue, May 30, 2023 at 6:36 PM Hugo Villeneuve <hugo@xxxxxxxxxxx> wrote:
> > On Tue, 30 May 2023 01:38:17 +0300
> > andy.shevchenko@xxxxxxxxx wrote:
> > > Mon, May 29, 2023 at 10:07:09AM -0400, Hugo Villeneuve kirjoitti:
>
> ...
>
> > > GENMASK()
> >
> > Ok done, altough even if in general I like the bit manipulation macros because they make the code easier to read/understand, I find it less obvious by using GENMASK in this case IMMO.
>
> GENMASK() was introduced to increase code robustness:
> 1) to make sure the bits mentioned are correct
> 2) to check the bit boundary.
>
> ...
>
> > > > + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> > > > + prop, p, u) {
> > > > + if (u >= devtype->nr_uart)
> > > > + continue;
> > > > +
> > > > + /* Use GPIO lines as modem control lines */
> > > > + if (u == 0)
> > > > + mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> > > > + else if (u == 1)
> > > > + mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> > > > + }
> > >
> > > Can we use device properties, please?
> >
> > I have converted this section to use device_property_count_u32() and device_property_read_u32_array(). Is that Ok?
>
> Yes, thank you!
>
> > > If you think about backporting to the earlier kernels (w/o properties in use in
> > > this driver), perhaps an additional followup for that?
> >
> > I am not sure what you mean by this?
>
> If the device property API was not yet available for this fix being
> backported to the old enough kernel we have to use old OF stuff. In
> that case the device property conversion needs to be done in a
> separate change.

Hi,.
ok, now I see.

Thank you,
Hugo.