On March 24, 2016 2:16:30 PM PDT, bryan.whiteh...@microchip.com wrote:
>> -----Original Message-----
>Hi Andrew,
>
>Sorry to bother you with this. But I'm having major difficulty with
>getting my dsa driver entry points called.
>
>Here is what I've done so far.
>
>I copied drivers/net/dsa/mv88x6060.c into
>drivers/net/dsa/mchp9352_dsa.c
>I then modified mchp9352_dsa.c as follows
>I emptied out the function bodies, and replaced them with a printk("Not
>Implemented\n");
>
>I did the same thing with net/dsa/tag_trailer.c which was copied into
>net/dsa/tag_mchp9352.c
>And function bodies were replaced with printk("Not Implemented\n");
>
>I also modified net/dsa/dsa.c, and net/dsa/slave.c, to include the
>hooks into my new tag files.
>
>My intent was to just see one of my "Not Implemented" functions called,
>and then I would focus on implementing it.
>
>But so far I have not seen any of my "Not Implemented" functions
>called.
>
>Here is what I know so far.
>
>It appears the dsa.c is not able to attach my underlying net device.
>And that seems to be due to it is unable to find the mdio_bus.
>So I modified my net device driver so that in probe it calls
>of_mdiobus_register instead of mdiobus_register.
>And of_mdiobus_register seems to be looking for some kind of phy
>definitions in the device tree, which it does not find. And so it does
>not appear to register the bus in such a way that dsa.c can connect to
>it.
If the lan9352 HW has a MDIO bus, which connects to internal switch, or PHYs
from the switch, there must be an mii_bus structure allocated and registered to
make that available.
>
>So the problem appears to be an issue with my device tree, which is
>partially shown below.
>
>&gpmc {
> status = "okay";
> ranges = <0 0 0x10000000 0x08000000>; // CS0: 128M
> pinctrl-names = "default";
> pinctrl-0 = <&gpmc_pins>;
> lan9352: ethernet@gpmc {
> compatible = "microchip,lan9352";
> interrupt-parent = <&gpio0>;
> interrupts = <7 8>;//7==GPIO bit 7, 8 = Active low level
> triggered.
>
> bank-width = <2>;
>
> phy-mode = "mii";
Having a phy-mode without a phy-handle property or fixed-phy subnode does not
sound correct nor useful.
Considering that you are interfaced to a built-in switch a fixed-link subnode
is needed to tell the Ethernet MAC about the link parameters. See
drivers/net/ethernet/broadcom/bcmsysport.c for an example by grepping for
fixed_phy.
>
> reg = <0 0 0x10000>;
>
> reg-io-width = <4>;
> microchip,save-mac-address;
> microchip,irq-push-pull;
>
> };
>};
>
>/ {
> dsa@0 {
> compatible = "microchip,dsa";
Did you also update net/dsa/dsa.c so it tries to match this compatible string?
DSA is right now a platform device (though there is pending working from Andrew
to change that) so we need a way to probe DSA.
> #address-cells = <2>;
> #size-cells = <0>;
> dsa,ethernet = <&lan9352>;
That looks correct.
> dsa,mii-bus = <&lan9352>;
But not that one, this must point to a device tree node which is a MDIO bus
controller. It could be a sub-node to lan9352 provided that there is a way to
expose a MDIO bus controller.
Moving forward, with Andrew's latest patches included, this may become entirely
optional, but it is not just now.
--
Florian
