Re: [RFC PATCH 1/4] pinctrl: renesas: rzg2l: Include pinmap in RZG2L_GPIO_PORT_PACK() macro

[Geert Uytterhoeven]

Hi Biju,

On Mon, Jul 3, 2023 at 4:13 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > -----Original Message-----
> > From: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
> > Sent: Monday, July 3, 2023 1:43 PM
> > To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>; Magnus Damm
> > <magnus.damm@xxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof
> > Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Linus Walleij
> > <linus.walleij@xxxxxxxxxx>; linux-renesas-soc@xxxxxxxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; linux-riscv@xxxxxxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; linux-gpio@xxxxxxxxxxxxxxx; Prabhakar Mahadev
> > Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Subject: Re: [RFC PATCH 1/4] pinctrl: renesas: rzg2l: Include pinmap in
> > RZG2L_GPIO_PORT_PACK() macro
> >
> > On Mon, Jul 3, 2023 at 12:42 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > wrote:
> > > > -----Original Message-----
> > > > From: Prabhakar <prabhakar.csengg@xxxxxxxxx>
> > > > Sent: Friday, June 30, 2023 1:05 PM
> > > > To: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>; Magnus Damm
> > > > <magnus.damm@xxxxxxxxx>
> > > > Cc: Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof Kozlowski
> > > > <krzysztof.kozlowski+dt@xxxxxxxxxx>; Linus Walleij
> > > > <linus.walleij@xxxxxxxxxx>; linux-renesas-soc@xxxxxxxxxxxxxxx;
> > > > devicetree@xxxxxxxxxxxxxxx; linux-riscv@xxxxxxxxxxxxxxxxxxx; linux-
> > > > kernel@xxxxxxxxxxxxxxx; linux-gpio@xxxxxxxxxxxxxxx; Biju Das
> > > > <biju.das.jz@xxxxxxxxxxxxxx>; Prabhakar
> > > > <prabhakar.csengg@xxxxxxxxx>; Prabhakar Mahadev Lad
> > > > <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > > > Subject: [RFC PATCH 1/4] pinctrl: renesas: rzg2l: Include pinmap in
> > > > RZG2L_GPIO_PORT_PACK() macro
> > > >
> > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > > >
> > > > Currently we assume all the port pins are sequential ie always PX_0
> > > > to PX_n (n=1..7) exist, but on RZ/Five SoC we have additional pins
> > > > P19_1 to
> > > > P28_5 which have holes in them, for example only one pin on port19
> > > > is available and that is P19_1 and not P19_0.
> > > >
> > > > So to handle such cases include pinmap for each port which would
> > > > indicate the pin availability on each port. With this we also get
> > > > additional pin validation, for example on the RZ/G2L SOC P0 has two
> > > > pins
> > > > P0_1 and P0_0 but with DT/SYSFS could use the P0_2-P0_7.
> > > >
> > > > While at it, update rzg2l_validate_gpio_pin() to use the port pinmap
> > > > to validate the gpio pin.
> > > >
> > > > Signed-off-by: Lad Prabhakar
> > > > <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > > > ---
> > > >  drivers/pinctrl/renesas/pinctrl-rzg2l.c | 167
> > > > ++++++++++++------------
> > > >  1 file changed, 86 insertions(+), 81 deletions(-)
> > > >
> > > > diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > > > b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > > > index 9511d920565e..a0c2e585e765 100644
> > > > --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > > > +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> > > > @@ -67,10 +67,12 @@
> > > >                                        PIN_CFG_FILCLKSEL)
> > > >
> > > >  /*
> > > > - * n indicates number of pins in the port, a is the register index
> > > > - * and f is pin configuration capabilities supported.
> > > > + * m indicates the bitmap of supported pins, n indicates number
> > > > + * of pins in the port, a is the register index and f is pin
> > > > + * configuration capabilities supported.
> > > >   */
> > > > -#define RZG2L_GPIO_PORT_PACK(n, a, f)        (((n) << 28) | ((a) <<
> > 20) |
> > > > (f))
> > > > +#define RZG2L_GPIO_PORT_PACK(m, n, a, f)     ((UL(m) << 32) |
> > (UL(n) << 28)
> > > > | ((a) << 20) | (f))
> > >
> > > I guess, you can still achieve RZG2L_GPIO_PORT_PACK(n, a, f) with
> > > ((UL(PINMAP(n)) << 32) | (UL(n) << 28) | ((a) << 20) | (f))
> > >
> > > #define PINMAP(n) GENMASK(n,0) ?? Then you don't need to modify
> > rzg2l_gpio_configs.
> > >
> > Good point, but this would work if port pins didn't have any holes.
> > For example on RZ/Five port P19 we have P19_1 pin only and P19_0 is not
> > available (and similarly for port P25 we have P25_1).
>
> Maybe introduce a helper macro to address this case.
>
> #define RZG2L_GPIO_PORT_PACK_WITH_HOLES(m, n, a, f) for these 2 cases

"sparse" is the terse term.

#define RZG2L_GPIO_PORT_PACK_SPARSE(m, a, f)
as "n" can be derived from "m"

> and use RZG2L_GPIO_PORT_PACK(n, a, f) for the one without holes.

Exactly.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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