Difference between revisions of "GPIO keys"

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m
m (For APF27)
Line 65: Line 65:
 
<source lang="c">
 
<source lang="c">
 
/* GPIO KEYS */
 
/* GPIO KEYS */
#if 1
+
#if defined(CONFIG_KEYBOARD_GPIO) || defined(CONFIG_KEYBOARD_GPIO_MODULE)
 
+
static struct gpio_keys_button apf27dev_gpio_keys[] = {
/* PORTA_6 used as gpio_keys (GPIO used as input event) */
+
static struct gpio_keys_button apf27_gpio_keys[] = {
+
 
{
 
{
.code = EV_PWR, /* See include/linux/input.h for more event code */
+
.code = BTN_EXTRA, /* See include/linux/input.h */
.gpio = (GPIO_PORTA | 6), /* GPIO number */
+
.gpio = (GPIO_PORTF | 13), /* GPIO number */
.active_low = 0,
+
.active_low = 1,
.desc = "Notification when the AC is deconnected", /* Button description*/
+
.desc = "s1", /* Button description*/
.type = 0, /* See include/linux/input.h for more type code */
+
.wakeup = 0,
 
},
 
},
 
};
 
};
  
static struct gpio_keys_platform_data apf27_gpio_keys_data = {
+
static struct gpio_keys_platform_data apf27dev_gpio_keys_data = {
.buttons = apf27_gpio_keys,
+
.buttons = apf27dev_gpio_keys,
.nbuttons = ARRAY_SIZE(apf27_gpio_keys),
+
.nbuttons = ARRAY_SIZE(apf27dev_gpio_keys),
 
};
 
};
  
static struct platform_device apf27_gpio_keys_device = {
+
static struct platform_device apf27dev_gpio_keys_device = {
 
.name = "gpio-keys",
 
.name = "gpio-keys",
.id = 0,
+
.id = -1,
 
.dev = {
 
.dev = {
.platform_data = &apf27_gpio_keys_data,
+
.platform_data = &apf27dev_gpio_keys_data,
 
},
 
},
 
};
 
};
# define GPIO_KEYS &apf27_gpio_keys_device,
+
#endif /* CONFIG_KEYBOARD_GPIO */
#else
+
 
# define GPIO_KEYS
+
#endif
+
 
</source>
 
</source>
  
Line 100: Line 96:
 
<source lang="c">
 
<source lang="c">
 
static struct platform_device *platform_devices[] __initdata = {
 
static struct platform_device *platform_devices[] __initdata = {
 +
#if defined(CONFIG_KEYBOARD_GPIO) || defined(CONFIG_KEYBOARD_GPIO_MODULE)
 +
&apf27dev_gpio_keys_device,
 +
#endif
 
ALSA_SOUND
 
ALSA_SOUND
GPIO_KEYS
 
 
};
 
};
 
</source>
 
</source>
  
 
[[Category:UserInput]]
 
[[Category:UserInput]]

Revision as of 19:14, 14 May 2012

Introduction

How to use gpio-keys driver to read states of the user switch of your Armadeus board. Your APF51|APF27|APF28 development board feature a user switch connected to a GPIO pin. The driver gpio-keys translates GPIO events in key/button events. Here are the GPIO used for the user button/switch for each APF board:

  • APF27: GPIO_PORTF | 13
  • APF28: PINID_GPMI_CE1N (Bank 0 - bit 17)
  • APF51: GPIO1_3

Test

# cat /dev/input/event0

Then you should see weirds characters when pressing the user button of the apf51_dev board:

 T
 ����T
      �T
        �
         ��T
            %�
  • if the test wiped out your console, you can get it back with:
# reset

You also can use the tool evtest.

Hardware handling  --->
     [*] input-tools
          [*]   evtest
 # evtest /dev/input/event0
...
Event: time 1335981358.550329, type 22 (EV_PWR), code 0 (), value 1
Event: time 1335981358.550330, -------------- SYN_REPORT ------------
Event: time 1335981358.550329, type 22 (EV_PWR), code 0 (), value 0
Event: time 1335981358.550330, -------------- SYN_REPORT ------------

For APF27

First, you need to enable the gpio_keys in your kernel.

Device Drivers  --->
     Input device support  --->
           <*>   Event interface
           [*]   Keyboards  --->
               <*>   GPIO Buttons

Then, in your apf27-dev.c, you need to define your GPIO button before the variable platform_devices[] and also include gpio_keys.h and input.h.

#include <linux/gpio_keys.h>
#include <linux/input.h>
/* GPIO KEYS */
#if defined(CONFIG_KEYBOARD_GPIO) || defined(CONFIG_KEYBOARD_GPIO_MODULE)
static struct gpio_keys_button apf27dev_gpio_keys[] = {
	{
		.code = BTN_EXTRA, /* See include/linux/input.h */
		.gpio = (GPIO_PORTF | 13), /* GPIO number */
		.active_low = 1,
		.desc = "s1", /* Button description*/
		.wakeup = 0,
	},
};

static struct gpio_keys_platform_data apf27dev_gpio_keys_data = {
	.buttons = apf27dev_gpio_keys,
	.nbuttons = ARRAY_SIZE(apf27dev_gpio_keys),
};

static struct platform_device apf27dev_gpio_keys_device = {
	.name = "gpio-keys",
	.id = -1,
	.dev = {
		.platform_data = &apf27dev_gpio_keys_data,
	},
};
#endif /* CONFIG_KEYBOARD_GPIO */

Add the button to get it recognized by the card.

static struct platform_device *platform_devices[] __initdata = {
#if defined(CONFIG_KEYBOARD_GPIO) || defined(CONFIG_KEYBOARD_GPIO_MODULE)
	&apf27dev_gpio_keys_device,
#endif
	ALSA_SOUND
};