diff mbox

ARM64: dts: meson-gxbb: set reset for ethernet

Message ID ec31eddc-d286-d0bc-0bdb-ae9d5014d82e@gmail.com (mailing list archive)
State Superseded
Headers show

Commit Message

Heiner Kallweit Jan. 29, 2017, 2:07 p.m. UTC
Add reset control for ethernet.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 2 ++
 1 file changed, 2 insertions(+)

Comments

Neil Armstrong Feb. 6, 2017, 9:29 a.m. UTC | #1
On 01/29/2017 03:07 PM, Heiner Kallweit wrote:
> Add reset control for ethernet.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@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().

Neil
Heiner Kallweit Feb. 7, 2017, 8:43 p.m. UTC | #2
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@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
>
Neil Armstrong Feb. 8, 2017, 8:45 a.m. UTC | #3
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@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
>>
>
diff mbox

Patch

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 {