linux gpio

[Jürgen Lambrecht]

Hello,

I am new to linux (coming from eCos).
My backlight driver does not start up because the reset gpio pin is not
correct specified.
How does gpio work in Linux?

I have 2 platforms that use the same backlight driver, under arm, for freescale imx: imx31_3ds and imx27_3ds.
I don't think that matters, I just need to understand the linux gpio.

The imx31 platform gives the number 88 as gpio number to the backlight
driver.
That number comes out of 'iomux-mx3.h'.
In 'iomux-mx27.h' the GPIO's are specified in an other way, the
"hardware" way, specifying bank and port. I think Linux GPIO needs a
sort of general gpio number.
But how do I calculate that number out of the datasheet?
In the imx31 datasheet, I cannot find that number 88 (or the other
numbers in 'iomux-mx3.h').

Kind regards,
Jürgen

-- 
Jürgen Lambrecht
R&D Associate
Tel: +32 (0)51 303045    Fax: +32 (0)51 310670
http://www.televic-rail.com
Televic Rail NV - Leo Bekaertlaan 1 - 8870 Izegem - Belgium
Company number 0825.539.581 - RPR Kortrijk