Hi Asha, On Fri, Jul 8, 2011 at 2:25 AM, Asha R <rd.asha22@gmail.com> wrote:
Hi,
I would like to know how to add new function to a driver in Linux Framework?
For eg: In GPIO driver, there is gpio_chip structure defined.
static struct gpio_chip mygpio_chip = { .label = "mygpio", .owner = THIS_MODULE, .direction_input = mygpio_direction_input, .get = mygpio_get, .direction_output = mygpio_direction_output, .set = mygpio_set, .to_irq = mygpio_to_irq, }; If i want to add mygpio_pulldown or mygpio_altfunc to support few more gpio functionalities, how and where can i add these functions in the structure?
It depends on whether you're trying to do it by modifying the gpio_chip structure, or want to "make an extension". If you want to modify the structure itself, you would do so here: http://lxr.linux.no/linux+v2.6.39/include/asm-generic/gpio.h#L90 If you want to make an extension, then you'd make your own structure which includes the gpio_chip structure as its first member. I often use this technique to add say an I/O address for the gpio bank, when there are multiple banks of gpio registers on a chip. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com