Re: [PATCH] pinctrl: Add generic pinctrl-simple driver thatsupports omap2+ padconf

From: Jean-Christophe PLAGNIOL-VILLARD
Date: Fri May 04 2012 - 11:59:59 EST


On 08:03 Fri 04 May , Tony Lindgren wrote:
> * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx> [120503 22:08]:
> >
> > In my mind in the driver we do not have to care how to list
> > register/unregister the group. We just need to be able to do this
> >
> > pinctrl_register_group(...)
> >
> > or
> >
> > pinctrl_unregistewr_group(...)
> >
> > On at91 we have this type of controller
>
> Ah I see. Yeah makes sense. Also I think we should let the pinctrl
> core eventually manage the pins more too. Right now the pins are
> a static array in the driver, which makes things unnecessarily
> complex for the DT case. It would be nice to also have something like
> pinctrl_register/unregister_pin instead of requiring them all
> be registered while registering with the framework initially.
>
> But all that can be improved later on once we get the binding down..
agreed at 100%
>
> > one pin can have multiple function and each function can be on different pin
> > and we need to program and represent each of them one by one
> >
> > And each pin have different parameter
> >
> > so I was thinking to do like on gpio
> >
> > uart {
> > pin = < &pioA 12 {pararms} >
> >
> > }
>
> Hmm I assume the "12" above the gpio number?
no pin number in the bank because it could not be gpio

evenif on at91 and nearly on the controller I known it is the case
>
> > and use macro as basicaly we are just this
> >
> > and this can be applied to tegra too as you will just refer the pin in this hw
> > pin block
>
> I was thinking of adding gpio eventually as a separate attribute with
> something like the following. Here cam_d10 pin is used as gpio109:
>
> cam_d10.gpio_109 {
> pinctrl-simple,cells = <0xfa 0x104>; /* OMAP_PIN_INPUT | OMAP_MUX_MODE4 */
> gpio = <&gpio4 13 0>; /* gpio109 */
> };
>
> The reasoning for this is that as we may not care about the gpio number
> for all pins, it should be optional. Would that work for you?
yes

but I was thinking to put it as a param but why not

my idea was this

pinctrl@fffff200 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "atmel,at91rm9200-pinctrl";

atmel,mux-mask = <
/* A B */
0xffffffff 0xffc003ff /* pioA */
0xffffffff 0x800f8f00 /* pioB */
0xffffffff 0x00000e00 /* pioC */
0xffffffff 0xff0c1381 /* pioD */
0xffffffff 0x81ffff81 /* pioE */
>;

pioA: gpio@fffff200 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffff200 0x100>;
interrupts = <2 4>;
#gpio-cells = <2>;
gpio-controller;
interrupt-controller;
};

pioB: gpio@fffff400 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffff400 0x100>;
interrupts = <3 4>;
#gpio-cells = <2>;
gpio-controller;
interrupt-controller;
};

pioC: gpio@fffff600 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffff600 0x100>;
interrupts = <4 4>;
#gpio-cells = <2>;
gpio-controller;
interrupt-controller;
};

pioD: gpio@fffff800 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffff800 0x100>;
interrupts = <5 4>;
#gpio-cells = <2>;
gpio-controller;
interrupt-controller;
};

pioE: gpio@fffffa00 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffffa00 0x100>;
interrupts = <5 4>;
#gpio-cells = <2>;
gpio-controller;
interrupt-controller;
};

dbgu {
pins = < &pioB 12 0 0
&pioB 13 0 2 >;
/* with macro */
pins = < &pioB 12 MUX_A NO_PULL_UP
&pioB 13 MUX_A PULL_UP >;
};

/* and also the notion of linked group
* as on uart of network you have often the same subset of pin use.
*
* As example on uart rxd/txd is use for the group without rts/cts
* and the one with it
* on ethernet the RMII pin are use also on MII
*/

uart0_rxd_txd {
pins = < &pioB 19 MUX_A PULL_UP /* rxd */
&pioB 18 MUX_A NO_PULL_UP >; /* txd */
};

uart0_rts_cts {
groups = < &uart0_rxd_txd >;
pins = < &pioB 17 MUX_B NO_PULL_UP /* rts */
&pioB 15 MUX_B NO_PULL_UP >; /* cts */
};

uart0_rts_cts_external_pull_up {
groups = < &uart0_rts_cts >;
gpios = <&pioC 1 0>;
};
};

The idea is to avoid duplication the xlate for pins will be driver specific
with maybe a common implementation

the 3 or 4 first fix as done on gpio

Best Regards,
J.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/