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Difference between revisions of "PandaBoard Button"

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(UserSpace Access)
(Adding New PushButtons)
 
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== Adding New PushButtons ==
 
== 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>
 
<pre>
Line 11: Line 11:
 
     [0] = {
 
     [0] = {
 
             .code     = 0x26,
 
             .code     = 0x26,
             .gpio          = S3C2410_GPG3,
+
             .gpio          = 39,
 
             .active_low    = 0,
 
             .active_low    = 0,
 
             .desc          = "PB0",
 
             .desc          = "PB0",
Line 22: Line 22:
 
};
 
};
 
 
static struct platform_device tct_hammer_buttons = {
+
static struct platform_device pandaboard_buttons = {
 
.name = "gpio-keys",
 
.name = "gpio-keys",
 
.id = 0,
 
.id = 0,
Line 30: Line 30:
 
};
 
};
 
</pre>
 
</pre>
 
 
  
 
== PushButton Hardware ==
 
== PushButton Hardware ==

Latest revision as of 18:42, 9 April 2012

UserSpace Access

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.

Adding New PushButtons

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.

static struct gpio_keys_button gpio_keys_buttons[] = {
    [0] = {
            .code	    = 0x26,
            .gpio           = 39,
            .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 pandaboard_buttons = {
	.name		= "gpio-keys",
	.id		= 0,
	.dev		= {
		.platform_data = &gpio_keys_data,
	},
};

PushButton Hardware

Pb-example-1v8.jpg