Subject: GPIO MPC8315 board

From: Vasanth Ragavendran <[email-masked]>
Date: Wed, 22 Jun 2011 01:56:06 -0700 (PDT)

Hi
 
I am using a MPC8315ERDB board. For this i've an external button which is
connected to GPIO pin 7 of the board. And if this button is pressed then
certain files have to be deleted. Browsing through the internet i found that
GPIO drivers have to be included into the kernel and hence i set a 'y' to
CONFIG_MPC8xxx_GPIO, CONFIG_GPIO_SYSFS and CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB
etc. And the dts file has be modified to include the following lines 
 
gpio1: gpio-controller@c00 {                
#gpio-cells = <2>;                
compatible = "fsl,mpc8315-gpio", "fsl,mpc8349-gpio";                
reg = <0xc00 0x100>;                
interrupts = <74 0x8>;                
interrupt-parent = <&ipic>;                
gpio-controller;         };          
 
this is included under immr@e0000000.
 
further i included
 
erase-button@0 {
compatible = "erase-button";
interrupts = <7 2>;
interrupt-parent = <&gpio1>;
};
 
am i right in including this? coz after compiling the kernel i get a folder
under /sys/class/gpio. I did an export using
 
echo 224 > /sys/class/gpio/export.
 
224 was the number appearing in gpiochip224/base.
 
It created another folder gpio224.
 
However i'm not able to set the value in them nor the direction.
 
echo 1 > /sys/class/gpio/gpio224/value
cat /sys/class/gpio/gpio224/value
returns a value of 0 only.
 
however the direction is "in"
cat /sys/class/gpio/gpio224/direction
in

Am i doing it correctly? How to check it programatically if the button is
pressed and take the corresponding action! Plz help!
 
My kernel version is 2.6.35.9.
 
Thanking you in advance.
-- 
View this message in context: http://old.nabble.com/GPIO-MPC8315-board-tp31901492p31901492.html
Sent from the linuxppc-dev mailing list archive at Nabble.com.