Hi Andrew,
On Fri, Apr 11, 2014 at 10:18:59AM +0200, Andrew Lunn wrote:
> On Thu, Apr 10, 2014 at 03:07:54PM +0200, Antoine Ténart wrote:
> > The uart0 pinmux configuration is in the dtsi because uart0 will always
> > use uart0-pmux to work, no other possibility. Same thing for uart1.
> >
> > Signed-off-by: Antoine Ténart <antoine.tenart@xxxxxxxxxxxxxxxxxx>
> > ---
> > arch/arm/boot/dts/berlin2.dtsi | 20 ++++++++++++++++++++
> > arch/arm/boot/dts/berlin2cd.dtsi | 13 +++++++++++++
> > arch/arm/boot/dts/berlin2q.dtsi | 20 ++++++++++++++++++++
> > 3 files changed, 53 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/berlin2.dtsi b/arch/arm/boot/dts/berlin2.dtsi
> > index 56a1af2f1052..43eb90c36050 100644
> > --- a/arch/arm/boot/dts/berlin2.dtsi
> > +++ b/arch/arm/boot/dts/berlin2.dtsi
> > @@ -176,6 +176,22 @@
> > };
> > };
> >
> > + pinctrl: pinctrl@0 {
> > + compatible = "marvell,berlin2-pinctrl";
> > + reg = <0xea0000 0x08>, <0xfc0000 0x44>;
> > + reg-names = "global_base", "apb_base";
> > +
> > + uart0_pmux: uart0-pmux {
> > + berlin,group = "GSM4";
> > + berlin,function = <0>;
> > + };
> > +
> > + uart1_pmux: uart1-pmux {
> > + berlin,group = "GSM5";
> > + berlin,function = <1>;
>
> Hi Antoine
>
> This very much looks like black magic.
>
> I assume the data sheet is not available? So i think you need to
> document all possible combinations of values of group and function.
> Maybe you can add a file in
>
> arch/arm/boot/dts/include/dt-bindings/pinctrl/
>
> with something like
>
> #define GSM4_UART0 0
> #define GSM5_UART1 1
> #define GSM12_UART0 1
> #define GSM12_IrDA0 1
> #define GSM12_GPIO 2
Groups' functions are not the same between BG2/BG2CD and BG2Q so multiple
headers would be needed which may not be a good thing. Some platforms use black
magic, and we can find a pinmux configuration for OMAP looking like:
0x128 (PIN_INPUT_PULLUP | MUX_MODE0)
Weel, we could explicitly define the functions in the driver itself and use in
the dt something like:
berlin,group = "GSM4";
berlin,function = "uart0";
This is what's done on the sunxi's pinctrl.
Antoine
--
Antoine Ténart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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