Re: [PATCH 3/4] arm: dts: gr-peach: Add ETHER pin group

Hi Jacopo,

On Thu, Aug 24, 2017 at 1:46 PM, jmondi [off-list ref] wrote:

On Thu, Aug 24, 2017 at 11:48:14AM +0200, Geert Uytterhoeven wrote:

quoted

On Thu, Aug 24, 2017 at 10:48 AM, Jacopo Mondi
[off-list ref] wrote:

quoted

Add pin configuration subnode for ETHER pin group.
The interface can be configured and probed, but no traffic can be
transmitted or received.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

---
When in u-boot console I can ping a connected host, after the
system has booted I can configure an ip address on the interface but
cannot exchange any traffic.
I have compared the pin configuration procedure with the u-boot
implemented one and some sketches from mbed operating system libraries,
the configured pins are correct and registers values seems to match.
Not sure if this patch should be sent for inclusion but sending it out
anyway for you to judge this.

quoted

All OK, but do you need P4_2, which is used for ET_nRST?

I tried requesting the GPIO in the "ether" subnode and define it as
"active low", so that it is kept high during regular operations.
I have verified through register writes dump it is cycled just after
the gpio is requested, and this should reset the interface before the
actual sh_eth driver kicks in.

I haven't find any mention in device tree bindings documentation of a
"reset-gpio" property for sh_eth, in the code examples I've seen in
u-boot and mbed, the interface is reset before any actual
configuration is performed. I feel like that should be the place where
that gpio is requested and cycled...

Documentation/devicetree/bindings/net/mdio.txt says

These are generic properties that can apply to any MDIO bus.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds