GPIO MPC8315 board

GPIO MPC8315 board

[Vasanth Ragavendran]

Hi
=20
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 tha=
t
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_GPIOLI=
B
etc. And the dts file has be modified to include the following lines=20
=20
gpio1: gpio-controller@c00 {               =20
#gpio-cells =3D <2>;               =20
compatible =3D "fsl,mpc8315-gpio", "fsl,mpc8349-gpio";               =20
reg =3D <0xc00 0x100>;               =20
interrupts =3D <74 0x8>;               =20
interrupt-parent =3D <&ipic>;               =20
gpio-controller;         };         =20
=20
this is included under immr@e0000000.
=20
further i included
=20
erase-button@0 {
compatible =3D "erase-button";
interrupts =3D <7 2>;
interrupt-parent =3D <&gpio1>;
};
=20
am i right in including this? coz after compiling the kernel i get a folder
under /sys/class/gpio. I did an export using
=20
echo 224 > /sys/class/gpio/export.
=20
224 was the number appearing in gpiochip224/base.
=20
It created another folder gpio224.
=20
However i'm not able to set the value in them nor the direction.
=20
echo 1 > /sys/class/gpio/gpio224/value
cat /sys/class/gpio/gpio224/value=EF=BB=BF
returns a value of 0 only.
=20
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!
=20
My kernel version is 2.6.35.9.
=20
Thanking you in advance.
--=20
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Re: GPIO MPC8315 board

[Martyn Welch]

On 22/06/11 09:56, Vasanth Ragavendran wrote:
> 
> 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
> 

echo "out" > /sys/class/gpio/gpio224/direction

Martyn

> 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.


-- 
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