PandaBoard Button - Revision history

Prpplague: /* Adding New PushButtons */

2012-04-09T18:42:01Z

‎Adding New PushButtons

Prpplague: /* UserSpace Access */

2012-04-09T18:40:08Z

‎UserSpace Access

Prpplague: /* PushButton Hardware */

2012-04-09T18:25:42Z

‎PushButton Hardware

Prpplague: Created page with "== UserSpace Access == the carrier board push button can be accessed via the sysfs interface as well as a shell script functionality. the sysfs entry for the push button can be ..."

2012-04-09T18:23:29Z

Created page with "== UserSpace Access == the carrier board push button can be accessed via the sysfs interface as well as a shell script functionality. the sysfs entry for the push button can be ..."

New page

== UserSpace Access ==

the carrier board push button can be accessed via the sysfs interface as well as a shell script functionality. the sysfs entry for the push button can be found in the directory mark /sys/devices/platform/gpio-keys.0 . the driver also looks for a shell script in /sbin called pb0.sh. this shell script can be used to start user land applications. here is the provided example shell script:

<pre>
#!/bin/sh

if [ $1 = "down" ] ; then
if [ -x /mnt/flash/scripts/pb0.down ] ; then
/mnt/flash/scripts/pb0.down
else
current=`cat /sys/class/leds/led1/brightness`
if [ "${current}" = 0 ] ; then
echo 1 > /sys/class/leds/led1/brightness
else
echo 0 > /sys/class/leds/led1/brightness
fi
fi
else
if [ -x /mnt/flash/scripts/pb0.up ] ; then
/mnt/flash/scripts/pb0.up
fi
fi#
</pre>

== Adding New PushButtons ==

the gpio buttons are defined in the linux-2.6.xx/arch/arm/mach-s3c2410/mach-tct_hammer.c file. each button requires that the gpio be defined, a name, and key scan code associated with it. in addition standard platform data and platform device have to be defined.

<pre>
static struct gpio_keys_button gpio_keys_buttons[] = {
[0] = {
.code = 0x26,
.gpio = S3C2410_GPG3,
.active_low = 0,
.desc = "PB0",
},
};

static struct gpio_keys_platform_data gpio_keys_data = {
.buttons = gpio_keys_buttons,
.nbuttons = ARRAY_SIZE(gpio_keys_buttons),
};

static struct platform_device tct_hammer_buttons = {
.name = "gpio-keys",
.id = 0,
.dev = {
.platform_data = &gpio_keys_data,
},
};
</pre>

== PushButton Hardware ==

[[Image:pb-example.jpg]]

[[Category:PandaBoard]]

@@ Line 5: / Line 5: @@
 == Adding New PushButtons ==
-the gpio buttons are defined in the linux-2.6.xx/arch/arm/mach-s3c2410/mach-tct_hammer.c file. each button requires that the gpio be defined, a name, and key scan code associated with it. in addition standard platform data and platform device have to be defined.
+the gpio buttons are defined in the linux kernel machine file. in this case for pandaboard it would be in  arch/arm/mach-omap2/board-omap4panda.c file. each button requires that the gpio be defined, a name, and key scan code associated with it. in addition standard platform data and platform device have to be defined.
 <pre>
@@ Line 11: / Line 11: @@
      [0] = {
              .code	    = 0x26,
-             .gpio           = S3C2410_GPG3,
+             .gpio           = 39,
              .active_low     = 0,
              .desc           = "PB0",
@@ Line 22: / Line 22: @@
 };
-static struct platform_device tct_hammer_buttons = {
+static struct platform_device pandaboard_buttons = {
 	.name		= "gpio-keys",
 	.id		= 0,
@@ Line 30: / Line 30: @@
 };
 </pre>
 == PushButton Hardware ==

@@ Line 1: / Line 1: @@
 == UserSpace Access ==
-the carrier board push button can be accessed via the sysfs interface as well as a shell script functionality. the sysfs entry for the push button can be found in the directory mark /sys/devices/platform/gpio-keys.0 . the driver also looks for a shell script in /sbin called pb0.sh. this shell script can be used to start user land applications. here is the provided example shell script:
+the push button can be accessed via the sysfs interface as well as a shell script functionality. the sysfs entry for the push button can be found in the directory marked /sys/devices/platform/ . each button will be listed as gpio-keys follow by a number.
-−
-<pre>
-#!/bin/sh
-−
-if [ $1 = "down" ] ; then
-    if [ -x /mnt/flash/scripts/pb0.down ] ; then
-        /mnt/flash/scripts/pb0.down
-    else
-        current=`cat /sys/class/leds/led1/brightness`
-        if [ "${current}" = 0 ] ; then
-            echo 1 > /sys/class/leds/led1/brightness
-        else
-            echo 0 > /sys/class/leds/led1/brightness
-        fi
-    fi
-else
-    if [ -x /mnt/flash/scripts/pb0.up ] ; then
-        /mnt/flash/scripts/pb0.up
-    fi
-fi#
-</pre>
-−
 == Adding New PushButtons ==

@@ Line 57: / Line 57: @@
 == PushButton Hardware ==
-[[Image:pb-example.jpg]]
+[[Image:pb-example-1v8.jpg]]
 [[Category:PandaBoard]]