基于输入子系统的GPIO按键的配置

      这几天看输入子系统，以下是在友善Tiny6410开发板上的基于输入子系统的GPIO按键驱动配置。GPN(5)在LCD Power里被占用了，故会在驱动加载时，提示error -16，即EBUSY。注释掉后，即可使用。

diff -uNr linux-2.6.38/arch/arm/mach-s3c64xx/mach-mini6410.c linux-2.6.38-jason//arch/arm/mach-s3c64xx/mach-mini6410.c
--- linux-2.6.38/arch/arm/mach-s3c64xx/mach-mini6410.c    2011-07-18 12:10:46.000000000 +0800
+++ linux-2.6.38-jason//arch/arm/mach-s3c64xx/mach-mini6410.c    2011-12-02 16:16:22.725178722 +0800
@@ -32,6 +32,8 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/proc_fs.h>
+#include <linux/gpio_keys.h>    //add by Jason
+#include <linux/input.h>    //add by Jason

 #include <video/platform_lcd.h>

@@ -333,7 +335,75 @@
 #endif
 };

+/* Tiny6410 Buttons */
+static struct gpio_keys_button tiny6410_buttons[] = {        //add by Jason
+    {
+        .gpio        = S3C64XX_GPN(0),
+        .code        = KEY_1,
+        .desc        = "key1",
+        .active_low    = 1,
+    },
+    {
+        .gpio        = S3C64XX_GPN(1),
+        .code        = KEY_2,
+        .desc        = "key2",
+        .active_low    = 1,
+    },
+    {
+        .gpio        = S3C64XX_GPN(2),
+        .code        = KEY_3,
+        .desc        = "key3",
+        .active_low    = 1,
+    },
+    {
+        .gpio        = S3C64XX_GPN(3),
+        .code        = KEY_4,
+        .desc        = "key4",
+        .active_low    = 1,
+    },
+    {
+        .gpio        = S3C64XX_GPN(4),
+        .code        = KEY_5,
+        .desc        = "key5",
+        .active_low    = 1,
+    },
+    /* be used by LCD
+    {
+        .gpio        = S3C64XX_GPN(5),
+        .code        = KEY_6,
+        .desc        = "key6",
+        .active_low    = 1,
+    },
+    */
+    {
+        .gpio        = S3C64XX_GPL(11),
+        .code        = KEY_7,
+        .desc        = "key7",
+        .active_low    = 1,
+    },
+    {
+        .gpio        = S3C64XX_GPL(12),
+        .code        = KEY_8,
+        .desc        = "key8",
+        .active_low    = 1,
+    },
+};
+
+static struct gpio_keys_platform_data tiny6410_button_data = {    //add by Jason
+    .buttons    = tiny6410_buttons,
+    .nbuttons    = ARRAY_SIZE(tiny6410_buttons),
+};
+
+static struct platform_device tiny6410_device_button = {    //add by Jason
+    .name    = "gpio-keys",
+    .id    = -1,
+    .dev    = {
+        .platform_data    = &tiny6410_button_data,
+    }
+};
+
 static struct platform_device *mini6410_devices[] __initdata = {
+    &tiny6410_device_button,                //add by Jason
 #ifdef CONFIG_MINI6410_SD_CH0
     &s3c_device_hsmmc0,
 #endif
diff -uNr linux-2.6.38/drivers/input/keyboard/gpio_keys.c linux-2.6.38-jason//drivers/input/keyboard/gpio_keys.c
--- linux-2.6.38/drivers/input/keyboard/gpio_keys.c    2011-03-18 17:02:19.000000000 +0800
+++ linux-2.6.38-jason//drivers/input/keyboard/gpio_keys.c    2011-12-02 15:42:44.369090912 +0800
@@ -373,8 +373,8 @@

     error = gpio_request(button->gpio, desc);
     if (error < 0) {
-        dev_err(dev, "failed to request GPIO %d, error %d\n",
-            button->gpio, error);
+        dev_err(dev, "failed to request GPIO %d, error %d\ndesc = %s",
+            button->gpio, error, desc);
         goto fail2;
     }