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SubjectRe: [RFC PATCH 4/4] pinctrl: renesas: pinctrl-rzg2l: Add support to get/set drive-strength and output-impedance
Hi Geert,

Thank you for the review.

On Thu, Oct 7, 2021 at 6:23 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Prabhakar,
>
> On Thu, Sep 30, 2021 at 2:17 PM Lad Prabhakar
> <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> > Add support to get/set drive-strength and output-impedance of the pins.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Thanks for your patch!
>
> > --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > @@ -47,6 +47,7 @@
> > #define PIN_CFG_FILONOFF BIT(9)
> > #define PIN_CFG_FILNUM BIT(10)
> > #define PIN_CFG_FILCLKSEL BIT(11)
> > +#define PIN_CFG_GROUP_B BIT(12)
>
> Perhaps it would be easier to have separate PIN_CFG_IOLH_A and
> PIN_CFG_IOLH_B flags, instead of a PIN_CFG_IOLH flag and a
> PIN_CFG_GROUP_B modifier flag?
>
Agreed will do that.

> >
> > #define RZG2L_MPXED_PIN_FUNCS (PIN_CFG_IOLH | \
> > PIN_CFG_SR | \
>
> > @@ -484,6 +513,38 @@ static int rzg2l_pinctrl_pinconf_get(struct pinctrl_dev *pctldev,
> > break;
> > }
> >
> > + case PIN_CONFIG_OUTPUT_IMPEDANCE:
> > + case PIN_CONFIG_DRIVE_STRENGTH: {
> > + unsigned int mA[4] = { 2, 4, 8, 12 };
> > + unsigned int oi[4] = { 100, 66, 50, 33 };
>
> static const
>
agreed.

> > +
> > + if (param == PIN_CONFIG_DRIVE_STRENGTH) {
> > + if (!(cfg & PIN_CFG_IOLH) || groupb_pin)
> > + return -EINVAL;
> > + } else {
> > + if (!(cfg & PIN_CFG_IOLH) || !groupb_pin)
> > + return -EINVAL;
> > + }
> > +
> > + spin_lock_irqsave(&pctrl->lock, flags);
> > +
> > + /* handle _L/_H for 32-bit register read/write */
> > + addr = pctrl->base + IOLH(port);
> > + if (bit >= 4) {
> > + bit -= 4;
> > + addr += 4;
> > + }
> > +
> > + reg = readl(addr) & (IOLH_MASK << (bit * 8));
> > + reg = reg >> (bit * 8);
> > + if (param == PIN_CONFIG_DRIVE_STRENGTH)
> > + arg = mA[reg];
> > + else
> > + arg = oi[reg];
> > + spin_unlock_irqrestore(&pctrl->lock, flags);
>
> I think you've reached the point where it starts to make sense to
> have helper functions to read and modify these sub-register fields
> that may be located into the current or next register.
>
Ok will add helpers to read and rmw.

> And after that, you can split it in two smaller separate cases for
> drive strength and output impedance.
>
Agreed.

Cheers,
Prabhakar

> > + break;
> > + }
> > +
> > default:
> > return -ENOTSUPP;
> > }
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds

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