[RFC] net: stmmac: Problem with adding the native GPIOs support

Serge Semin Sergey.Semin at baikalelectronics.ru
Wed Dec 16 00:31:34 EST 2020

On Wed, Dec 16, 2020 at 03:03:55AM +0100, Andrew Lunn wrote:
> > > From what you are saying, it sounds like from software you cannot
> > > independently control the GPIO controller reset?
> > 
> > No. The hardware implements the default MAC reset behavior. So the
> > GPIO controller gets reset synchronously with the MAC reset and that
> > can't be changed.

> Is there pinmux support for these pins?  Can you disconnect them from
> the MAC? Often pins can be connected to different internal IP
> blocks. Maybe you can flip the pin mux, perform the MAC reset, and
> then put the pinmux back to connect the pins to the MAC IP again?

Alas no. Pins multiplexing isn't implemented in the Baikal-T1 SoC at all.
Each pin has been assigned with a single function. In this case DW GMAC
GPO/GPI pins always serve as GPO/GPI and nothing else.


>      Andrew

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