On 02/26/2013 05:06 PM, Stephen Warren wrote: > On 02/26/2013 04:01 PM, Jon Hunter wrote: >> >> 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 > > Oh, when I clicked that link the first time, all I saw was the patch, > not any discussion. I guess it must have timed out finding the other > emails or something.
Actually, I sent a slightly different link the 2nd time to ensure you saw the thread. So my fault ;-) > I disagree that the GPIO needs to be requested, and that a custom DT > property and associated code are needed for that; simply requesting the > IRQ should be enough to make everything work. > > In the Tegra GPIO IRQ driver for example, the irq_set_type irq_chip op > goes and configures the base GPIO HW to enable the pin as a GPIO, just > like gpio_request() would. I imagine the OMAP driver can do whatever > similar action it needs. Yes that is similar to what the patch in the thread was attempting to do, but this got shot down. One issue I see is that by not calling gpio_request, then potentially you could have someone request a gpio via gpio_request() and someone trying to use it as an interrupt source via request_irq(). Now obviously that represents a bug because there is only one physical gpio, but I gather it is something we need to protect against. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html