[PATCH] ARM64: dts: meson-gxbb: set reset for ethernet

[Heiner Kallweit]

Am 06.02.2017 um 10:29 schrieb Neil Armstrong:
> On 01/29/2017 03:07 PM, Heiner Kallweit wrote:
>> Add reset control for ethernet.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
>> ---
>>  arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> index 39a774ad..753fddf6 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
>> @@ -113,6 +113,8 @@
>>  		 <&clkc CLKID_FCLK_DIV2>,
>>  		 <&clkc CLKID_MPLL2>;
>>  	clock-names = "stmmaceth", "clkin0", "clkin1";
>> +	resets = <&reset RESET_ETHERNET>;
>> +	reset-names = "stmmaceth";
>>  };
>>  
>>  &aobus {
>>
> 
> Hi,
> 
> Actually this is a no-op since the Amlogic reset controller only supports "pulse" resets and the
> STMMAC driver only supports "level" resets. If you want to use this reset, you must add the
> corresponding support code in the meson8b glue code to call device_reset().
> 
Thanks for the hint! I did some further tests to check the "nature" of the reset register bits.
Setting a reset bit and immediately reading it back always returns 0.
And the chip spec doesn't mention whether writing a reset bit triggers a reset pulse or
whether it asserts the reset line.
Therefore I'm a little clueless whether it's possible to have "level" resets.

> Neil
>