On Tue, Feb 26, 2013 at 11:40 PM, Jon Hunter [off-list ref] wrote:

On 02/26/2013 04:01 AM, Javier Martinez Canillas wrote:

[snip]

quoted

I was wondering if the level/edge settings for gpios is working on OMAP.

I'm adding DT support for an SMSC911x ethernet chip connected to the
GPMC for an OMAP3 SoC based board.

In the smsc911x driver probe function (smsc911x_drv_probe() in
drivers/net/ethernet/smsc/smsc911x.c), a call to request_irq() with
the flag IRQF_TRIGGER_LOW is needed because of the wiring on my board.

Reading the gpio-omap.txt documentation it says that #interrupt-cells
should be <2> and that a value of 8 is "active low level-sensitive".

So I tried this:

&gpmc {
      ethernet at 5,0 {
              pinctrl-names = "default";
              pinctrl-0 = <&smsc911x_pins>;
              compatible = "smsc,lan9221", "smsc,lan9115";
              reg = <5 0 0xff>; /* CS5 */
              interrupt-parent = <&gpio6>;
              interrupts = <16 8>; /* gpio line 176 */
              interrupt-names = "smsc911x irq";
              vmmc-supply = <&vddvario>;
              vmmc_aux-supply = <&vdd33a>;
              reg-io-width = <4>;

              smsc,save-mac-address;
      };
};

Are you requesting the gpio anywhere? If not then this is not going to
work as-is. This was discussed fairly recently [1] and the conclusion
was that the gpio needs to be requested before we can use as an interrupt.

I have not seen your latest smsc code for omap, but when you are
requesting the gpmc chip-select you should also request the gpio.

Yes, I realized that requesting the gpio was necessary so what I did
is to use the "regulator-fixed" optional property "gpio" and define
the GPIO used as an IRQ in a regulator used by the SMSC chip. So, I
have this on my board DT:

vddvario: regulator-vddvario {
	compatible = "regulator-fixed";
	regulator-name = "vddvario";
	regulator-always-on;
	gpio = <&gpio6 16 8>;  /* gpio line 176 */
	enable-active-high;
	gpio-open-drain;
	regulator-boot-on;
};

&gpmc {
	ethernet at 5,0 {
		pinctrl-names = "default";
		pinctrl-0 = <&smsc911x_pins>;
		compatible = "smsc,lan9221", "smsc,lan9115";
		reg = <5 0 0xff>;
		interrupt-parent = <&gpio6>;
		interrupts = <16 8>; /* gpio line 176 */
		interrupt-names = "smsc911x irq";
		vmmc-supply = <&vddvario>;
		vmmc_aux-supply = <&vdd33a>;
		reg-io-width = <4>;

		smsc,save-mac-address;
      };
};

That way a call to gpio_request_one() is made and the GPIO is requested.

This look a little hack-ish for me but I've seen this in other
DeviceTrees like omap4-sdp.dts so I thought it was a common DT
pattern.

quoted

But in the smsc911x probe function:

irq_res->flags & IRQF_TRIGGER_MASK;

returns 0 which means that no trigger flags where set.

I took a look to the GPIOs device node definition on omap{3,4,5}.dtsi
and all look like this:

e.g from omap3.dtsi:

                gpio6: gpio at 49058000 {
                        compatible = "ti,omap3-gpio";
                        ti,hwmods = "gpio6";
                        gpio-controller;
                        #gpio-cells = <2>;
                        interrupt-controller;
                        #interrupt-cells = <1>;
                };

So, even when the documentation says that all the GPIO device nodes in
OMAP2+ should use a #interrupt-cells property value of <2>, they are
only using <1>. Changing that value to 2 makes hangs the kernel and it
does not boot.

I will need to take a look at that. Is your code available anywhere so I
can test?

Of course, I pushed a gpmc-smsc911x branch to my github linux repository [2].

The branch is latest Linus' master + Benoit's linux-omap-dt/for_3.9/dts +
"ARM: OMAP2+: Prevent potential crash if GPMC probe fails" [3] +
"ARM: dts: OMAP3: Add GPMC controller" [4] + my patches:

Javier Martinez Canillas (5):
      ARM: dts: OMAP3: reduce GPMC mapped registers address space
      ARM: dts: OMAP3: make GPMC node compatible with simple-bus
      ARM: dts: OMAP3: add ranges property for GPMC chip-select 5
      ARM: dts: omap3-igep0020: Add SMSC911x LAN chip support
      smsc: smc911x: (HACK) force "active low" polarity for IRQ

The last patch is just an ugly hack that forces the IRQ flags to
active low level-sensitive so the SMSC911x IRQ is triggered on my
board (IGEPv2).

I just added for testing purposes since the omap3-gpio
interrupt-controller #interrupt-cells = <2> seems to not be working
and I can't pass this flag when defining the IRQ in the smsc911x
ethernet device node.

Cheers
Jon

Thanks a lot for your help and best regards,
Javier

[1]: http://permalink.gmane.org/gmane.linux.ports.arm.omap/92192
[2]: https://github.com/martinezjavier/linux.git
[3]: https://patchwork.kernel.org/patch/2118831/
[4]: https://patchwork.kernel.org/patch/2057111/