How to use gpio-omap as interrupt-controller

How to use gpio-omap as interrupt-controller

[Lars Poeschel]

Hi!

I have a device-tree-booting omap board that uses gpio-omap as gpio driver. 
Kernel version is 3.11.0-rc4. I have connected a device that signals 
interrupts to a gpio pin of the omap. The driver for this device fails in 
request_threaded_irq.
The irq framework tries to setup the irq in __setup_irq which calls 
gpio_irq_type in gpio-omap.c. This function checks if bank->mod_usage is 
set and because it is not, the function fails. Looking at where bank-
>mod_usage is set, I see it is only set in omap_gpio_request.
This means I have to request at least one random gpio to be able to set the 
type of the irq of another pin on this bank ?
How do I correctly use the gpio-omap gpio driver in my case ?
The board is booting using device tree and does not request a gpio prior to 
requesting the irq on this gpio bank. I really do not want to request a 
gpio. They should stay as they are.
Or does this mean the driver of the connected device is wrong and instead 
it has to request some random gpio before ?

An example of such a connected device is gpio-adnp by the way.
The device tree part looks like this:

		gpioext: gpio-adnp@41 {
			compatible = "ad,gpio-adnp";
			reg = <0x41>;

			interrupt-parent = <&gpio>;
			interrupts = <160 1>;

			gpio-controller;
			#gpio-cells = <1>;

			interrupt-controller;
			#interrupt-cells = <2>;

			nr-gpios = <64>;
		};

Regards,
Lars

Re: How to use gpio-omap as interrupt-controller

[Santosh Shilimkar]

On Thursday 08 August 2013 11:23 AM, Lars Poeschel wrote:
> Hi!
> 
> I have a device-tree-booting omap board that uses gpio-omap as gpio driver. 
> Kernel version is 3.11.0-rc4. I have connected a device that signals 
> interrupts to a gpio pin of the omap. The driver for this device fails in 
> request_threaded_irq.
> The irq framework tries to setup the irq in __setup_irq which calls 
> gpio_irq_type in gpio-omap.c. This function checks if bank->mod_usage is 
> set and because it is not, the function fails. Looking at where bank-
>> mod_usage is set, I see it is only set in omap_gpio_request.
> This means I have to request at least one random gpio to be able to set the 
> type of the irq of another pin on this bank ?
> How do I correctly use the gpio-omap gpio driver in my case ?
> The board is booting using device tree and does not request a gpio prior to 
> requesting the irq on this gpio bank. I really do not want to request a 
> gpio. They should stay as they are.
> Or does this mean the driver of the connected device is wrong and instead 
> it has to request some random gpio before ?
> 
> An example of such a connected device is gpio-adnp by the way.
> The device tree part looks like this:
> 
> 		gpioext: gpio-adnp@41 {
> 			compatible = "ad,gpio-adnp";
> 			reg = <0x41>;
> 
> 			interrupt-parent = <&gpio>;
> 			interrupts = <160 1>;
> 
> 			gpio-controller;
> 			#gpio-cells = <1>;
> 
> 			interrupt-controller;
> 			#interrupt-cells = <2>;
> 
> 			nr-gpios = <64>;
> 		};
> 
You hit the issue which we tried to address but ended
up reverting the patches. refer [1], [2] for more
information. For now, its broken unfortunately.
Regards,
Santosh


[1] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg91405.html
[2] https://lkml.org/lkml/2013/7/29/280