On Tue, Feb 26, 2013 at 11:40 PM, Jon Hunter <jon-hunter@xxxxxx> wrote:
>
> On 02/26/2013 04:01 AM, Javier Martinez Canillas wrote:
>
> [snip]
>
>> 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@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@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.
>> 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@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/
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