/*  fii-dt-driver.c - The simplest kernel module.
 
* Copyright (C) 2013 - 2016 Xilinx, Inc
*
*   This program is free software; you can redistribute it and/or modify
*   it unde r the terms of the GNU General Public License as published by
*   the Free Software Foundation; either version 2 of the License, or
*   (at your option) any later version.
 
*   This program is distributed in the hope that it will be useful,
*   but WITHOUT ANY WARRANTY; without even the implied warranty of
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*   GNU General Public License for more details.
*
*   You should have received a copy of the GNU General Public License along
*   with this program. If not, see <http://www.gnu.org/licenses/>.
 
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>  /* for put_user */
 
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
 
/* Standard module information, edit as appropriate */
MODULE_LICENSE("GPL");
MODULE_AUTHOR
    ("FII inc.");
MODULE_DESCRIPTION
    ("fii-dt-driver - loadable module template generated by petalinux-create -t modules");
 
#define DRIVER_NAME "fii-dt-driver"
 
static const struct of_device_id  of_match_fii_dt_driver[] = {
//    {.compatible = "fii,fii-dt-driver", .data = NULL},
    {.compatible = "fii,fii-dt-driver", },
    {/*sentinel*/},
};
 
static struct class  *fii_dt_driver_class;
 
static unsigned int major;
static unsigned int * gpio_base;
static unsigned int * gpio_data;
static unsigned int * gpio_dir;
 
static int fii_dt_driver_init(void);
 
static int fii_dt_driver_open(struct inode* node,struct file* filp){
 
    gpio_data = ioremap(gpio_base, 8);
    if(gpio_data){
        printk("kernel: ioremap(0x%08x)=0x%08x \n", gpio_base, gpio_data);
    }
    else{
        return -EINVAL;
    }
 
    gpio_dir = gpio_data + 1;
 
    return 0;
}
 
static int fii_dt_driver_release(struct platform_device * dev)
{
    iounmap(gpio_data);
    
    unregister_chrdev(major, "fii-dt-driver");
    device_destroy(fii_dt_driver_class,MKDEV(major,0));
    class_destroy(fii_dt_driver_class);    
    
    return 0;
}
  
static ssize_t fii_dt_driver_read(struct file *filp, char *buf, size_t size, loff_t *offset)
{
    unsigned char val[32];
    unsigned int temp;
    unsigned int *addr_p;
    int i,cnt;
    printk("kernel: fii-dt-driver read start.... size = %d\n", size);
    cnt = size;
 
    addr_p = gpio_data;
    temp = *addr_p ;
    for(i = 0; i < cnt/4; i++ )
    {
        val[i*4 + 3] = temp & 0xff;
        val[i*4 + 2] = (temp >> 8) & 0xff;
        val[i*4 + 1] = (temp >> 16) & 0xff;
        val[i*4 + 0] = (temp >> 24) & 0xff;
        addr_p ++;
        temp = *addr_p;
    }
    
    if(i % 4 == 1)
    {
        val[i*4 + 0] = temp & 0xff;
    }
    if(i % 4 == 2)
    {
        val[i*4 + 1] = temp & 0xff;
        val[i*4 + 0] = (temp >> 8) & 0xff;
    }
    if(i % 4 == 3)
    {
        val[i*4 + 2] = temp & 0xff;
        val[i*4 + 1] = (temp >> 8) & 0xff;
        val[i*4 + 0] = (temp >> 16) & 0xff;
    }
 
    copy_to_user(buf, val, cnt);
 
    return cnt;
}
 
static ssize_t fii_dt_driver_write(struct file * filp, const char __user *buf, size_t size, loff_t * offset) {
    unsigned char val[32];
    unsigned int temp = 0;
    unsigned int * addr_p;
    int i,cnt;
 
    memset(val,0,32);
    addr_p = gpio_data;
 
    printk("kernel: fii-dt-driver write start.... size = %d\n", size);
    copy_from_user(&val, buf, size);
    cnt = size - 1;
 
    printk("kernel: val[0] = 0x%08x \n", val[0]);
 
    if(val[0] == 'w')
    {
        temp = val[2];
        temp = temp << 8 | val[3];
        temp = temp << 8 | val[4];
        temp = temp << 8 | val[5];
 
        *addr_p = temp;
        printk("kernel: gpio_data = 0x%08x \n", temp);
    }
    
    else if(val[0] == 'd')
    {
        addr_p ++;
        temp = val[2];
        temp = temp << 8 | val[3];
        temp = temp << 8 | val[4];
        temp = temp << 8 | val[5];
 
        *addr_p = temp;
        printk("kernel: gpio_dir = 0x%08x \n", temp);
    }
    else
    {
        printk("kernel: invalid parameter \n");
    }
  
    return size;
}
 
static struct file_operations fii_dt_driver_oprs = {
 
    .owner      = THIS_MODULE,
    .open       = fii_dt_driver_open,
    .write      = fii_dt_driver_write,
    .read       = fii_dt_driver_read,
};
 
static int fii_dt_driver_probe(struct platform_device *pdev)
{
    struct resource *res;
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    printk ("kernel: enter fii_dt_driver probe ...... \n");
    
    res = platform_get_resource(pdev, IORESOURCE_MEM,0);
 
    if(res){
        gpio_base = res->start;
    }
 
    major=register_chrdev(0, "fii-dt-driver", &fii_dt_driver_oprs);
    if (major < 0) {
         printk ("Registering the character device failed with %d\n", major);
        return major;
    }
 
    fii_dt_driver_class = class_create(THIS_MODULE, "fii-dt-driver_class");
    device_create(fii_dt_driver_class,NULL,MKDEV(major,0),NULL,"fii-dt-driver");
    
    return 0;
}
 
MODULE_DEVICE_TABLE(of, of_match_fii_dt_driver);
 
static struct platform_driver fii_dt_driver_drv = {
    .driver     = {
        .name   = "fii-dt-driver",
        .owner  = THIS_MODULE,
        .of_match_table = of_match_fii_dt_driver,
    },
    .probe      = fii_dt_driver_probe,
    .remove     = fii_dt_driver_release,
};
 
 
static int fii_dt_driver_init(void){       /* register device  */
    printk(KERN_ERR "|||||||||||||||||||||||||||||||||||||||||||||||| \r\n");
    printk(KERN_ERR "|||||||||||||||||||||||||||||||||||||||||||||||| \r\n");
    printk(KERN_ERR "|||||||||||||||||||||||||||||||||||||||||||||||| \r\n");
    printk(KERN_ERR "\r\n");
 
    // #############################################
    // OF FUNCTIONS THAT FIND NODES TEST CODE INSERT
    // #############################################
 
    printk(KERN_ERR "\r\n");
    printk(KERN_ERR "################################################ \r\n");
    printk(KERN_ERR "\r\n");
 
    // ##########################################################
    // OF FUNCTIONS THAT FIND PARENT/CHILD NODES TEST CODE INSERT
    // ##########################################################
 
    printk(KERN_ERR "\r\n");
    printk(KERN_ERR "################################################ \r\n");
    printk(KERN_ERR "\r\n");
 
    // ##########################################################
    // OF FUNCTIONS THAT EXTRACT PROPERTY VALUES TEST CODE INSERT
    // ##########################################################
 
    printk(KERN_ERR "\r\n");
    printk(KERN_ERR "################################################ \r\n");
    printk(KERN_ERR "\r\n");
 
    // ##########################################
    // OTHER COMMON OF FUNCTIONS TEST CODE INSERT
    // ##########################################
 
    printk(KERN_ERR "\r\n");
    printk(KERN_ERR "||||||||||||||||||||||||||||||||||||||||||||| \r\n");
    printk(KERN_ERR "||||||||||||||||||||||||||||||||||||||||||||| \r\n");
    printk(KERN_ERR "||||||||||||||||||||||||||||||||||||||||||||| \r\n");
 
    return platform_driver_register(&fii_dt_driver_drv);
 
}
 
 
static void fii_dt_driver_exit(void){
 
    platform_driver_unregister(&fii_dt_driver_drv);
    return;
};
 
module_init(fii_dt_driver_init);
module_exit(fii_dt_driver_exit);
 
MODULE_ALIAS("platform:fii-dt-driver");