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

[Jon Hunter <jon-hunter@ti.com>]

On 02/26/2013 04:44 PM, Stephen Warren wrote:
> 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@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.

I agree that ideally this should be handled internally. Did you read the
discussion on the thread that I referenced [1]? If you have any thoughts
we are open to ideas :-)

Cheers
Jon

[1] http://comments.gmane.org/gmane.linux.ports.arm.omap/92192