[PATCH] ARM64: dts: meson-gxbb: set reset for ethernet
Neil Armstrong
narmstrong at baylibre.com
Wed Feb 8 00:45:37 PST 2017
On 02/07/2017 09:43 PM, Heiner Kallweit wrote:
> 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.
It seems that there is some "level" register in the next addresses used by the VPU reset in u-boot,
but I did not get the same behaviour as the pulse reset registers.
It seems the resets are not mapped the same way.
Neil
>
>> Neil
>>
>
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