Subject: [PATCH 3/5] gpio/omap: Add DT support to GPIO driver

From: [email-masked] (Stephen Warren)
Date: Tue, 26 Feb 2013 15:44:01 -0700

On 02/26/2013 03:40 PM, Jon Hunter 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 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.

That seems wrong; the GPIO/IRQ driver should handle this internally. The
Ethernet driver shouldn't know/care whether the interrupt it's given is
some form of dedicated interrupt or a GPIO-based interrupt, and even if
it somehow did, there's no irq_to_gpio() any more, so the driver can't
tell which GPIO ID it should request, unless it's given yet another
property to represent this.