Re: [PATCH 4/7] ARM: dts: sun6i: Add simplefb node

[Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Hi,

On 11/13/2014 05:46 PM, Maxime Ripard wrote:
> Hi,
> 
> On Thu, Nov 13, 2014 at 10:31:46AM +0100, Hans de Goede wrote:
>> Add a simplefb template node for u-boot to further fill and activate.
>>
>> Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> ---
>>  arch/arm/boot/dts/sun6i-a31.dtsi | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
>> index 543f895..438952e 100644
>> --- a/arch/arm/boot/dts/sun6i-a31.dtsi
>> +++ b/arch/arm/boot/dts/sun6i-a31.dtsi
>> @@ -62,6 +62,16 @@
>>  		ethernet0 = &gmac;
>>  	};
>>  
>> +	chosen {
>> +		#address-cells = <1>;
>> +		#size-cells = <1>;
>> +		ranges;
>> +
>> +		framebuffer0 {
>> +			compatible = "simple-framebuffer";
>> +			status = "disabled";
> 
> Aren't we suppose to have clocks in there too?

I deliberately left them out as they are not needed on sun6i, once the blocks
are setup ahb access is not necessary, but it seems that the ahb_gate bits
in sun4i / sun5i / sun7i double as a reset. Toggling them on / off / on breaks
the mode, while toggling module clocks on / off / on only causes a glitch.

Since the sun6i has a separate reset controller, the clock gates seem to really
only control ahb access which is not necessary once the mode has been set up.

Regards,

Hans