基于sysfs的led驱动程序

sysfs

1.以下是在原有添加button支持后的mach-mini6410-button.c diff出来的，行数会和标准的mach-mini6410.c不同，不能靠打补丁的方式添加。但是可以看出哪些是添加的，若要修改，可自行添加。压缩包里是我现在正在用的mach-mini6410.c的修改版。

 mach-mini6410-button-led.zip   

--- mach-mini6410-button.c    2011-12-06 18:47:19.263062596 +0800
+++ mach-mini6410-button-led.c    2011-12-06 16:18:30.000000000 +0800
@@ -34,6 +34,7 @@
 #include <linux/proc_fs.h>
 #include <linux/gpio_keys.h>    //add by Jason
 #include <linux/input.h>    //add by Jason
+#include <linux/leds.h>        //add by Jason

 #include <video/platform_lcd.h>

@@ -402,8 +403,51 @@
     }
 };

+/* Tiny6410 Leds */
+static struct gpio_led tiny6410_leds[] = {            //add by Jason
+    [0] = {
+        .name        = "LED1",
+        .default_trigger= "heartbeat",
+        .gpio        = S3C64XX_GPK(4),
+        .active_low    = 1,
+        .default_state    = LEDS_GPIO_DEFSTATE_OFF,
+    },
+    [1] = {
+        .name        = "LED2",
+        .gpio        = S3C64XX_GPK(5),
+        .active_low    = 1,
+        .default_state    = LEDS_GPIO_DEFSTATE_OFF,
+    },
+    [2] = {
+        .name        = "LED3",
+        .gpio        = S3C64XX_GPK(6),
+        .active_low    = 1,
+        .default_state    = LEDS_GPIO_DEFSTATE_OFF,
+    },
+    [3] = {
+        .name        = "LED4",
+        .gpio        = S3C64XX_GPK(7),
+        .active_low    = 1,
+        .default_state    = LEDS_GPIO_DEFSTATE_OFF,
+    },
+};
+
+static struct gpio_led_platform_data tiny6410_gpio_led_data = {    //add by Jason
+    .leds        = tiny6410_leds,
+    .num_leds    = ARRAY_SIZE(tiny6410_leds),
+};
+
+static struct platform_device tiny6410_device_led = {        //add by Jason
+    .name    = "leds-gpio",
+    .id    = -1,
+    .dev    = {
+        .platform_data    = &tiny6410_gpio_led_data,
+    },
+};
+
 static struct platform_device *mini6410_devices[] __initdata = {
     &tiny6410_device_button,                //add by Jason
+    &tiny6410_device_led,                    //add by Jason
 #ifdef CONFIG_MINI6410_SD_CH0
     &s3c_device_hsmmc0,
 #endif

2.驱动配置在图形化配置菜单里选：

Device Driver ---> Led Support

如下图配置

3.重新烧写新的内核，启动后，会看到led0在闪烁，因为配置了heartbeat，要控制其余几个led灯，可以如下输入：

a.点灯

echo 1 > /sys/devices/platform/leds-gpio/leds/LED3/brightness

b.熄灯

echo 0 > /sys/devices/platform/leds-gpio/leds/LED3/brightness