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#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#include <asm/io.h>

static struct class *SW106LedClass;

//STATUS-LED:PE7

#define PIO_BASE (0x0300B000)

volatile unsigned long *PortECFG[4] = {NULL};
volatile unsigned long *PortEData = NULL;

static int SW106LedOpen(struct inode *inode, struct file *file)
{
   //configure PE7 to output mode
   uint32_t lastValue = *PortECFG[0];
   lastValue &= 0x1fffffff;
   *PortECFG[0] &= lastValue;
   printk("led opened %ld\n",*PortECFG[0]);
   return 0;
}

static ssize_t SW106LedWrite(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
   int val;
   copy_from_user(&val, buf, count);
   printk("led write %d\n",val);
   if (val == 1)
      *PortEData |= (1 << 7);
   else
      *PortEData &= ~(1 << 7);

   return 0;
}

static struct file_operations SW106LedFileOp = {
      .owner = THIS_MODULE,
      .open = SW106LedOpen,
      .write = SW106LedWrite,
};

int major;

int SW106LedInit(void)
{
   major = register_chrdev(0, "led", &SW106LedFileOp);
   SW106LedClass = class_create(THIS_MODULE, "led");
   device_create(SW106LedClass, NULL, MKDEV(major, 0), NULL, "led");

   PortECFG[0] = (volatile unsigned long*)(PIO_BASE+0x24*4);
   
   PortECFG[1] = PortECFG[0] + 4;
   PortEData = (volatile unsigned long*)(PIO_BASE+0xA0);
   printk("portecfg %X portedata %X\n",PortECFG[0],PortEData);
   return 0;
}

static void SW106LedExit(void)
{
   unregister_chrdev(major, "led");
   device_destroy(SW106LedClass, MKDEV(major, 0));
   class_destroy(SW106LedClass);
   iounmap(PortECFG[0]);
}

module_init(SW106LedInit);
module_exit(SW106LedExit);

MODULE_AUTHOR("JustQin");
MODULE_DESCRIPTION("SW GPIO USER driver");
MODULE_LICENSE("GPL");