Re: [PATCH 1/4] ARM: dts: add support for hdmi to exynos4

[Tomasz Figa <tomasz.figa@gmail.com>]

Hi Rahul,

On Monday 28 of January 2013 12:25:27 Rahul Sharma wrote:
> Hi Thomas,
> 
> On Fri, Jan 25, 2013 at 11:10 PM, Thomas Abraham
> 
> <thomas.abraham@linaro.org> wrote:
> > On 25 January 2013 02:39, Rahul Sharma <rahul.sharma@samsung.com> 
wrote:
> >> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
> >> 
> >> Conflicts:
> >>         arch/arm/mach-exynos/mach-exynos4-dt.c
> >> 
> >> ---
> >> 
> >>  arch/arm/boot/dts/exynos4.dtsi         | 7 +++++++
> >>  arch/arm/mach-exynos/mach-exynos4-dt.c | 2 ++
> >>  2 files changed, 9 insertions(+)
> >> 
> >> diff --git a/arch/arm/boot/dts/exynos4.dtsi
> >> b/arch/arm/boot/dts/exynos4.dtsi index e1347fc..6c2c79d 100644
> >> --- a/arch/arm/boot/dts/exynos4.dtsi
> >> +++ b/arch/arm/boot/dts/exynos4.dtsi
> >> @@ -289,4 +289,11 @@
> >> 
> >>                         interrupts = <0 34 0>;
> >>                 
> >>                 };
> >>         
> >>         };
> >> 
> >> +
> >> +       hdmi {
> >> +               compatible = "samsung,exynos4-hdmi14";
> >> +               reg = <0x12D00000 0x70000>;
> >> +               interrupts = <0 95 0>;
> >> +               hpd-gpio = <&gpx3 7 0xf 1 3>;
> > 
> > This is using the older gpio dt bindings but exynos4 has started using
> > the pinctrl bindings. So this is not sufficient to do the
> > pinmux/pinconfig settings on Exynos4.
> > 
> > Thanks,
> > Thomas.
> 
> I have chosen this as exynos5 DT using it in same way and parsed by
> common code in driver for exy4 and 5. Secondly, one-time initial
> configuration is sufficient for
> hdmi hpd-gpio. Please share your opinion.

Exynos4 SoCs use pin control for pin mux configuration, which implies 
different GPIO specifiers than what you used. On Exynos4 generic GPIO 
specifiers are used:

<&gpio-controller pin flags>

As you can see, it does not contain pin mux configuration, which must be 
configured if special function is to be used. In case of EINTs and 
input/output functions, they are configured automatically, respectively by 
request_irq (with appropriate interrupt trigger flag) and gpio_direction_*.

Keep in mind that Exynos5 will be eventually moved to pin control as well 
and its old GPIO bindings will be dropped as they are only temporary.

Best regards,
Tomasz