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hyunjun_cho authoredhyunjun_cho authored
lcd_dev.c 4.05 KiB
//#include "bcm2835.h"
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#define IR_MAJOR_NUMBER 504
#define IR_DEV_NAME "lcd_dev"
#define I2C_BASE_ADDR 0x3F804000
#define DLEN 0x08
#define FIFO 0x10
#define S 0x04
#define C 0x00
#define DIV 0x14
#define BSC_A 0x0C
static void __iomem *i2c_base;
volatile unsigned int *i2c, paddr;
int lcd_open(struct inode *inode, struct file *filp){
printk(KERN_ALERT "LCD sensor driver open!!\n");
i2c_base = ioremap(I2C_BASE_ADDR, 0xFF);
i2c=(volatile unsigned int*)(i2c_base);
return 0;
}
int lcd_release(struct inode *inode, struct file *filp){
printk(KERN_ALERT "Infrared distance sensor driver closed!!\n");
return 1;
}
ssize_t lcd_write(struct file* flip, const char* buf, size_t count, loff_t* f_pos){
char* kbuf;
kbuf=kmalloc(count, GFP_KERNEL);
copy_from_user(kbuf, buf, 1);
//printk(KERN_ALERT "SEX: %x\n", *kbuf);
//char buffer[1];
//buffer[0]=0x01;
unsigned int len=1;
volatile unsigned int* dlen = (volatile unsigned int*)(i2c_base + DLEN);
volatile unsigned int* fifo = (volatile unsigned int*)(i2c_base + FIFO);
volatile unsigned int* status = (volatile unsigned int*)(i2c_base + S);
volatile unsigned int* control = (volatile unsigned int*)(i2c_base + C);
volatile unsigned int* bsc_a = (volatile unsigned int*)(i2c_base + BSC_A);
*bsc_a = 0x3F;
unsigned int remaining=len;
unsigned int i=0;
unsigned int reason = 0;
*control |= 0x20;
*status = (0x200 | 0x100 | 0x02);
*dlen = len;
while(remaining &&(i<16)){
*fifo = kbuf[i];
i++;
remaining--;
}
*control = (0x8000|0x80);
while(!(*status & 0x02)){
while(remaining && (*status & 0x10)){
*fifo = kbuf[i];
i++;
remaining--;
}
}
if(*status & 0x100)
reason = 1;
else if(*status & 0x200)
reason = 2;
else if(remaining)
reason = 4;
*control |= 0x02;
printk(KERN_ALERT "reason: %d\n", reason);
//copy_to_user(buf, &reason, sizeof(int));
return 0;
}
/*
ssize_t lcd_read(struct file *filp, char *buf, size_t size, loff_t *f_pos){
int
char buffer[1];
buffer[0]=0x01;
unsigned int len=1;
volatile unsigned int* dlen = (volatile unsigned int*)(i2c_base + DLEN);
volatile unsigned int* fifo = (volatile unsigned int*)(i2c_base + FIFO);
volatile unsigned int* status = (volatile unsigned int*)(i2c_base + S);
volatile unsigned int* control = (volatile unsigned int*)(i2c_base + C);
unsigned int remaining=len;
unsigned int i=0;
unsigned int reason = 0;
*control |= 0x20;
*status = (0x200 | 0x100 | 0x02);
*dlen = len;
while(remaining &&(i<16)){
*fifo = buffer[i];
i++;
remaining--;
}
*control = (0x8000|0x80);
while(!(*status & 0x02)){
while(remaining && (*status & 0x10)){
*fifo = buffer[i];
i++;
remaining--;
}
}
if(*status & 0x100)
reason = 1;
else if(*status & 0x200)
reason = 2;
else if(remaining)
reason = 4;
*control |= 0x02;
printk(KERN_ALERT "reason: %d\n", reason);
copy_to_user(buf, &reason, sizeof(int));
return 0;
return size;
}
*/
static struct file_operations ir_fops = {
.owner = THIS_MODULE,
.open = lcd_open,
.release = lcd_release,
.write = lcd_write
};
int __init lcd_init(void){
if(register_chrdev(IR_MAJOR_NUMBER, IR_DEV_NAME, &ir_fops) < 0)
printk(KERN_ALERT "LCD initialization failed\n");
else
printk(KERN_ALERT "LCD initialization success\n");
return 0;
}
void __exit lcd_exit(void){
unregister_chrdev(IR_MAJOR_NUMBER, IR_DEV_NAME);
printk(KERN_ALERT "LCD driver exit done");
}
module_init(lcd_init);
module_exit(lcd_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("MW");
MODULE_DESCRIPTION("joreka");