how to know the Interrupt/GPIO number for a specific pin in linux

Question

i'm doing a project in which i need to handle an interrupt in Linux.

the board i'm using is an ARM9Board based on the s3c6410 MCU by Samsung (arm 11 processor) and it has the following I/O interface :

enter image description here

as the image shows i have EINTx pins for external interrupts and GPxx pins as GPIO pins and i don't mind using any of them but i don't have their numbers !

For EINTx pins :

when i call

int request_irq(unsigned int irq, void (*handler)(int, struct pt_regs *), 
unsigned long flags, const char *device);

i need the interrupt number to pass it as the first paramter of the function , so how can i get the irq number for example the EINT16 pin ?

For GPxx pins : the same story as i need the GPIO pin nuumber to pass it to those functions

int gpio_request(unsigned gpio, const char *label);
int gpio_direction_input(unsigned gpio);
int gpio_to_irq(unsigned gpio);

i.e how do i know the GPIO number for the GPP8 pin ?

i searched the board documents and datasheet but it doesn't contain anything about how to get those numbers , any idea or help on where to look ?

embedded.kyle embedded.kyle · Accepted Answer · 2012-06-26T17:45:17

The Embedded Linux you are using should have a GPIO driver that has #define statements for the GPIO pins. You can then get the IRQ number of the specific GPIO using something like:

irq_num = gpio_to_irq(S3C64XX_GPP(8));

The Linux GPIO lib support for that particular chip is available in the following file:

linux/arch/arm/mach-s3c6400/include/mach/gpio.h

There you will find all the #define statements for the various GPIO.

See the section on GPIO Conventions in their documentation:

http://www.kernel.org/doc/Documentation/gpio/gpio.txt

how to know the Interrupt/GPIO number for a specific pin in linux

2 Answers