#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm/mach/irq.h>
#include <asm/arch/regs-gpio.h>
#include <linux/poll.h>
#include <linux/platform_device.h>

/* 參考arch/arm/plat-s3c24xx/devs.c */

/*1. 根據晶片手冊來獲取資源*/
static struct resource led_resource[] = {
 [0] = {
  .start = 0x56000050,
  .end   = 0x56000057,
  .flags = IORESOURCE_MEM,
 },
 [1] = {
  .start = 5,
  .end   = 5,
  .flags = IORESOURCE_IRQ,
 },
};

void led_release(struct device *dev)
{ 

}

/*1.構建平臺裝置結構體，將平臺資源加入進來*/
struct platform_device

/*2。把我們的裝置資源掛在到虛擬匯流排的裝置連表中去*/
int led_dev_init(void)
{
 platform_device_register(&led_device);   
 return 0;
}

void led_dev_exit(void)
{
 platform_device_unregister(&led_device);
}

module_init(led_dev_init);
module_exit(led_dev_exit);

MODULE_LICENSE("GPL"); 

#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <asm/mach/irq.h>
#include <asm/arch/regs-gpio.h>
#include <linux/poll.h>
#include <linux/platform_device.h>

static int major = 0;

static volatile unsigned long *gpio_con;
static volatile unsigned long *gpio_dat;
static int pin;
static struct class *cls;

int led_open(struct inode *inode, struct file *file)
{
 /* 設定對應的引腳為輸出引腳 */

 *gpio_con &= ~(0x3 << (pin * 2));
 *gpio_con |= (0x1 << (pin * 2));
 
 return 0;
}

ssize_t led_write(struct file *file, const char __user *buf, size_t size, loff_t *offset)
{
 char ker_buf[1];
 
 /* 根據buf傳入的值點/滅燈 */
 /* buf[0] - 亮/滅 , 0 - 亮, 1 - 滅 */

 if (size != 1)
 {
  return -EINVAL;
 }

 copy_from_user(ker_buf, buf, 1);
 
 if ((ker_buf[0] != 0) && (ker_buf[0] != 1))
  return -EINVAL;

 if (ker_buf[0])
 {
  // 某個LED
  *gpio_dat |= (0x1<< pin);
 }
 else
 {
  // 某個LED
  *gpio_dat &= ~(0x1<<pin);
 }
 
 return 1;
}

/*4實現操作硬體的方法*/
static struct file_operations led_fops = {
 .owner  = THIS_MODULE,
 .open   = led_open,
 .write  = led_write,
};

/*3。實現probe函式*/
static int led_probe(struct platform_device *dev)
{
 struct resource *r;
 
 /* 根據平臺裝置確定點哪一個LED */
 r = platform_get_resource(dev, IORESOURCE_MEM, 0);

 /*獲取到資源以後再進行對映*/
 gpio_con = ioremap(r->start, r->end - r->start + 1);
 gpio_dat = gpio_con + 1;

 r = platform_get_resource(dev, IORESOURCE_IRQ, 0);
 pin = r->start;

 /* 註冊驅動向核心裡面註冊我們的字元裝置驅動 */
 major = register_chrdev(0, "led", &led_fops);

 /* sysfs  ==> 掛接到/sys */
 cls = class_create(THIS_MODULE, "led_class");
 class_device_create(cls, NULL, MKDEV(major, 0), NULL, "led");

 // mdev會根據/sys下的這些內容建立/dev/led

 return 0;
}

int led_remove(struct platform_device *dev)
{
 unregister_chrdev(major, "led");
 class_device_destroy(cls, MKDEV(major, 0));
 class_destroy(cls);
 iounmap(gpio_con);  
 return 0;
}

/*1。構建平臺驅動結構體，不知道的時候可以看別人的*/
static struct platform_driver led_driver = {
 .probe  = led_probe,     /* 平臺匯流排下增加一個平臺裝置時，呼叫列舉函式 */
 .remove  = led_remove,    /* 平臺匯流排下去掉一個平臺裝置時，呼叫remove函式 */
 .driver  = {
  .name = "myled",       /* 能支援名為"myled"的平臺裝置 */
  .owner = THIS_MODULE,
 },
};

/*2。註冊，把我們的驅動加入到平臺裝置驅動連表中去*/
static int led_drv_init(void)
{
 platform_driver_register(&led_driver);
 return 0;
}

static int led_drv_exit(void)
{
 platform_driver_unregister(&led_driver);
 return 0;
}

module_init(led_drv_init);
module_exit(led_drv_exit);

MODULE_LICENSE("GPL");