[PATCH v2 10/11] ARM: dts: stm32: add ethernet1 and ethernet2 for STM32MP135F-DK board

[Marek Vasut]

On 5/13/24 6:01 PM, Alexandre TORGUE wrote:
> Hi Marek

Hi,

> On 4/26/24 17:44, Marek Vasut wrote:
>> On 4/26/24 2:57 PM, Christophe Roullier wrote:
>>> Add dual Ethernet:
>>> -Ethernet1: RMII with crystal
>>> -Ethernet2: RMII without crystal
>>> PHYs used are SMSC (LAN8742A)
>>>
>>> With Ethernet1, we can performed WoL from PHY instead of GMAC point
>>> of view.
>>> (in this case IRQ for WoL is managed as wakeup pin and configured
>>> in OS secure).
>>
>> How does the Linux PHY driver process such a PHY IRQ ?
>>
>> Or is Linux unaware of the PHY IRQ ? Doesn't that cause issues ?
> 
> In this case, we want to have an example to wakeup the system from 
> Standby low power mode (VDDCPU and VDD_CORE off) thanks to a magic 
> packet detected by the PHY. The PHY then assert his interrupt output 
> signal.
> On MP13 DK platform, this PHY signal is connected to a specific GPIO
> aka "Wakeup pins" (only 6 wakeup pins an MP13). Those specific GPIOs are 
> handled by the PWR peripheral which is controlled by the secure OS.

What does configure the PHY for this wakeup mode ?

> On WoL packet, the Secure OS catches the PHY interrupt and uses 
> asynchronous notification mechanism to warn Linux (on our platform we 
> use a PPI). On Linux side, Optee core driver creates an irq 
> domain/irqchip triggered on the asynchronous notification. Each device 
> which use a wakeup pin need then to request an IRQ on this "Optee irq 
> domain".
> 
> This OPTEE irq domain will be pushed soon.

I suspect it might make sense to add this WoL part separately from the 
actual ethernet DT nodes, so ethernet could land and the WoL 
functionality can be added when it is ready ?