led can now glow

src/io.c

@@ -2,6 +2,7 @@
 #define LCD_IO_H_
 
 #include <linux/fs.h>
+#include <linux/gpio.h>
 #include "lcd.h"
 
 loff_t lcd_llseek(struct file* filp, loff_t where, int whence)
@@ -30,12 +31,17 @@ int lcd_open(struct inode* inode, struct file* filp)
     dev = container_of(inode->i_cdev, struct lcd_dev, dev);
     filp->private_data = (void*)dev;
 
+    gpio_set_value(dev->gpio, 1);
+
     printk(KERN_INFO "%s: Opened device\n", THIS_MODULE->name);
     return 0;
 }
 
 int lcd_release(struct inode* inode, struct file* filp)
 {
+    struct lcd_dev* dev;
+    dev = (struct lcd_dev*)filp->private_data;
+    gpio_set_value(dev->gpio, 0);
     printk(KERN_INFO "%s: Released device\n", THIS_MODULE->name);
     return 0;
 }

src/lcd.c

@@ -2,6 +2,7 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/fs.h>
+#include <linux/gpio.h>
 
 #include "lcd.h"
 
@@ -17,6 +18,9 @@ static struct lcd_dev lcddev = { 0 };
 static int  __init lcd_init_cdev(void);
 static void __exit lcd_exit_cdev(void);
 
+static int  __init lcd_init_gpio(void);
+static void __exit lcd_exit_gpio(void);
+
 extern loff_t   lcd_llseek  (struct file*, loff_t, int);
 extern ssize_t  lcd_read    (struct file*, char __user*, size_t, loff_t*);
 extern ssize_t  lcd_write   (struct file*, const char __user*, size_t, loff_t*);
@@ -60,12 +64,17 @@ static int __init lcd_init_module(void)
     if(result < 0)
         return result;
 
+    result = lcd_init_gpio();
+    if(result < 0)
+        return result;
+
     printk(KERN_INFO "%s: Module loaded!\n", THIS_MODULE->name);
     return result;
 }
 
 static void __exit lcd_exit_module(void)
 {
+    lcd_exit_gpio();
     lcd_exit_cdev();
     unregister_chrdev_region(lcddev.devno, 1);
 
@@ -94,3 +103,15 @@ static void __exit lcd_exit_cdev(void)
 {
     cdev_del(&lcddev.dev);
 }
+
+static int  __init lcd_init_gpio(void)
+{
+    lcddev.gpio = 18;
+    gpio_direction_output(lcddev.gpio, 0);
+    return 0;
+}
+
+static void __exit lcd_exit_gpio(void)
+{
+    
+}

src/lcd.h

@@ -14,6 +14,7 @@ struct lcd_dev
 {
     dev_t devno;
     struct cdev dev;
+    int gpio;
 };
 
 #endif