#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <linux/syscalls.h>
#include <linux/kfifo.h>
#include <linux/version.h>
#include <linux/spinlock.h>
#include "drv_devices.h"
#include "drv_uartb.h"

#define IRQ_UARTB 54

struct kfifo uartb_fifo;
DEFINE_SPINLOCK(uart_write_lock);

static void __set_baudrate_low(unsigned int baudrate)
{
    unsigned int dl;
    
    dl = baudrate * 64 / 375;
    *(volatile unsigned int *) 0xbe0d0114 = dl;
    clear_bit(15,(volatile void __iomem *)0xbe00002c);
}

static void __set_baudrate_high(unsigned int baudrate)
{
#if defined(CONFIG_CHIP_8503)
    if (baudrate == 230400)
        *(unsigned char *)0xbe00018e = 0xff;
    else if (baudrate == 460800)
        *(unsigned char *)0xbe00018e = 0xbf;
    else if (baudrate == 921600)
        *(unsigned char *)0xbe00018e = 0x9f;
#elif defined(CONFIG_CHIP_8506)
    if (baudrate == 230400)
        return;
    else if (baudrate == 460800)
        *(unsigned char *)0xbe00018e = 0xfa;
    else if (baudrate == 921600)
        *(unsigned char *)0xbe00018e = 0xbc;
#elif defined(CONFIG_CHIP_6710)
    if (baudrate == 230400)
        return;
    else if (baudrate == 460800)
        *(unsigned char *)0xbe00018e = 0xe1;
    else if (baudrate == 921600)
        *(unsigned char *)0xbe00018e = 0xb0;
#elif defined(CONFIG_CHIP_8501)
    if (baudrate == 230400)
        return;
    else if (baudrate == 460800)
        *(unsigned char *)0xbe00018e = 0xd5;
    else if (baudrate == 921600)
        *(unsigned char *)0xbe00018e = 0xb5;
#elif defined(CONFIG_CHIP_533) || defined(CONFIG_CHIP_512L)
    if (baudrate == 230400)
        return;
    else if (baudrate == 460800)
        *(unsigned char *)0xbe00018e = 0xe2;
    else if (baudrate == 921600)
        *(unsigned char *)0xbe00018e = 0xb1;
#endif

    set_bit(15,(volatile void __iomem *)0xbe00002c);

}

static void uartb_set_baudrate(unsigned int baudrate)
{
    unsigned long flags;
    
    spin_lock_irqsave(&uart_write_lock, flags);
    
    switch (baudrate) {
    case 9600:
    case 14400:
    case 19200:
    case 38400:
    case 57600:
    case 115200:
        __set_baudrate_low(baudrate);
        break;
    case 230400:
    case 460800:
    case 921600:
        __set_baudrate_high(baudrate);
        break;
    }
    
    spin_unlock_irqrestore(&uart_write_lock, flags);
}

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,8)
long uartb_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
#else
static ssize_t uartb_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
#endif
{
    switch (cmd) {
        case UARTB_SET_BAUDRATE:
            uartb_set_baudrate(arg);
            break;
    }
    return 0;
}


static ssize_t uartb_write(struct file *filp, const char __user *uBuff, size_t count, loff_t *f_pos)
{

    unsigned char *kBuff;
    unsigned int off_irq_flag=0;
	
    off_irq_flag = (unsigned int)count & 0x8000;
    count &= 0x7fff;
    if((kBuff=(unsigned char *)kmalloc(count, GFP_KERNEL))==NULL)
    {
        printk(KERN_EMERG"audiorx_write: no enough memory to do !!!\n");
        return count;
    }
    if(copy_from_user(kBuff, uBuff, count))
    {
        printk(KERN_EMERG"audiorx_write: copy_from_user error !!!\n");
    }
    else
    {
        unsigned int i;
        unsigned long flags;
        if (off_irq_flag)
        	spin_lock_irqsave(&uart_write_lock, flags);
        for (i = 0; i < count; i++) {
            while(! ((*(volatile  unsigned int *)0xbe0d0110)&0x00006000));
            writeb(kBuff[i], (volatile unsigned char *)0xbe0d0104);
        }
        if (off_irq_flag)
        	spin_unlock_irqrestore(&uart_write_lock, flags);
        //AI_write(kBuff, count);
    }
    kfree(kBuff);


    return count;
}

static ssize_t uartb_read(struct file *filp, char __user *uBuff, size_t count, loff_t *f_pos)
{
    size_t i,ret;
    size_t max_count;

    unsigned char tmp_buf[512];
	
	memset(tmp_buf,0x0,sizeof(tmp_buf));
	
    max_count = (count < 512)? count: 512;
    //printk("<0> max_count = %d\n",max_count);
    for (i = 0; i < max_count; i++) {
        if (kfifo_is_empty(&uartb_fifo) != 0) {
            //printk("<0>kfifo_is_empty\n");
            break;
        }
        ret = kfifo_out(&uartb_fifo, &tmp_buf[i], sizeof(unsigned char));
        //printk("<0>c=%c\n",tmp_buf[i]);
        if (ret != sizeof(unsigned char))
            return -EINVAL;
    }

    if (copy_to_user(uBuff, tmp_buf, count)) {
        printk("<0> copy_to_user error!\n");
        i = -EFAULT;
    }
    return i;
}

static int uartb_open(struct inode *i, struct file *f)
{
    printk("<0>file open\n");
	kfifo_reset(&uartb_fifo);

#if defined(CONFIG_XHDMICPIN_TO_UARTB)
	//UARTB output from XHDMIC_SDA & XHDMIC_SCL
	set_bit(2, (volatile void __iomem *)0xbe000010);

#elif defined(CONFIG_KEY1_I2S_SCK_TO_UARTB)
    //KEY1 as UARTB_RX
	clear_bit(20, (volatile void __iomem *) 0xbe0f0600);
	set_bit(21, (volatile void __iomem *)0xbe0f0600);

    //I2C_SCK as UARTB_TX
	clear_bit(2, (volatile void __iomem *) 0xbe0f0600);
	clear_bit(3, (volatile void __iomem *) 0xbe0f0600);
	set_bit(15, (volatile void __iomem *) 0xbe00012c);
	clear_bit(8, (volatile void __iomem *) 0xbe00013c);//R_I2S_OEJ
	clear_bit(26, (volatile void __iomem *) 0xbe00013c);

#else
    //LVB_TXN4 as UARTB_RX
	set_bit(14, (volatile void __iomem *) 0xbe00012c);
   #if (CONFIG_CHIPID == 0x533)
	set_bit(9, (volatile void __iomem *) 0xbe0000ec);
   #else
	clear_bit(9, (volatile void __iomem *) 0xbe00025c);
	clear_bit(17, (volatile void __iomem *) 0xbe00025c);
   #endif

	//LVA_TXN4 as UARTB_TX
	set_bit(14, (volatile void __iomem *) 0xbe00012c);
   #if (CONFIG_CHIPID == 0x533)
	clear_bit(4, (volatile void __iomem *) 0xbe0000ec);
   #else
	clear_bit(4, (volatile void __iomem *) 0xbe00025c);
	clear_bit(17, (volatile void __iomem *) 0xbe00025c);
   #endif
#endif

    return 0;
}

static int uartb_close(struct inode *i, struct file *f)
{
    printk("<0>uartb_close\n");
	
#ifdef CONFIG_XHDMICPIN_TO_UARTB
	clear_bit(2, (volatile void __iomem *) 0xbe000010);

#elif defined(CONFIG_KEY1_I2S_SCK_TO_UARTB)
	clear_bit(21, (volatile void __iomem *)0xbe0f0600);
	
	set_bit(8, (volatile void __iomem *) 0xbe00013c);
	clear_bit(15, (volatile void __iomem *) 0xbe00012c);
#else
    clear_bit(14, (volatile void __iomem *) 0xbe00012c);
   #if (CONFIG_CHIPID == 0x533)
	clear_bit(9, (volatile void __iomem *) 0xbe0000ec);
   #else
    set_bit(9, (volatile void __iomem *) 0xbe00025c);
    set_bit(4, (volatile void __iomem *) 0xbe00025c);
   #endif
#endif
    return 0;
}

static irqreturn_t uartb_ISR( int irq, void* dev_id )
{
    int i;
    unsigned int rec_fifo, indicator;
    unsigned char c;
    //printk("<0> irq=%d\n",irq);
    if (kfifo_is_full(&uartb_fifo)) {
        printk("<0> [UARTB] kfifo is full!!\n");
        *(volatile unsigned int *) 0xbe0d0110 =  *(volatile unsigned int *) 0xbe0d0110; //w1c
        return IRQ_HANDLED;
    }
    rec_fifo = *(volatile unsigned int *) 0xbe0d0100;		/* plz read 000, then 00c , hw limit, Gaia*/
	indicator = (*(volatile unsigned int *) 0xbe0d010c) & 0xf;

	for(i=0; indicator!=0; i++){
		indicator = indicator >>1;
		c = rec_fifo >> (i*8);
        if (kfifo_is_full(&uartb_fifo) == 0)
            kfifo_in(&uartb_fifo, &c, sizeof(unsigned char));
        else
            break;
	}
    //printk("<0> len = %d\n",kfifo_len(&uartb_fifo));
    *(volatile unsigned int *) 0xbe0d0110 =  *(volatile unsigned int *) 0xbe0d0110; //w1c

    return IRQ_HANDLED;

}

static void uartb_dispatch(void)
{
    do_IRQ(IRQ_UARTB);
}
static struct file_operations uartb_fops = {
    owner : THIS_MODULE,
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,8))
	unlocked_ioctl : uartb_ioctl,
#else
	ioctl : uartb_ioctl,
#endif
    open : uartb_open,
    release : uartb_close,
    write : uartb_write,
    read : uartb_read,
};

/*
static struct file_operations uartb_fops = {
    .ioctl = uartb_ioctl,
    .write = uartb_write,
    .open = uartb_open,
	.release = uartb_close,
    .owner = THIS_MODULE,
};
*/
struct cdev *cdev_uartb;

int uartb_init(void)
{
    int ret,err;
    dev_t   devno = MKDEV(UARTB_MAJOR, 0);
	
    err=register_chrdev_region(devno, 1, "uartb");
	if(err)
	{
		return -EIO;
	}
    cdev_uartb = cdev_alloc();
    cdev_uartb->owner = THIS_MODULE;
    cdev_uartb->ops = &uartb_fops;
    err=cdev_add(cdev_uartb, devno, 1);
	if(err)
	{
		return -EIO;
	}
    set_vi_handler(IRQ_UARTB, uartb_dispatch);

    ret = request_irq(IRQ_UARTB, &uartb_ISR, IRQF_DISABLED, "uartb", NULL);
		
    *(volatile unsigned short *) 0xbe0d0114 = 0x666;//baud rate:115200，0x00000666:9600
    *(volatile unsigned int *) 0xbe0d0128 = 0;
    *(volatile unsigned int *) 0xbe0d0108 = 0x00200307;
    *(volatile unsigned int *) 0xbe0d0110 =  *(volatile unsigned int *) 0xbe0d0110;

	while (*(volatile unsigned char *)0xbe0d010c)
		ret = (int) *(volatile unsigned int *)0xbe0d0100;

    ret = kfifo_alloc(&uartb_fifo, PAGE_SIZE, GFP_KERNEL);
    if (ret < 0)
        printk("<0>[UARTB] kfifo alloc error!");
    return ret;
}

#ifdef CONFIG_SUPPORT_UARTB
module_init(uartb_init);
#endif
//MODULE_LICENSE("Dual BSD/GPL");