grove-lcd-karnel-mod/mod.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <asm/uaccess.h>

#include "Grove_LCD_rgb_V2.0.h"

// ADD device i2c
// echo grove_lcd 0x3e | sudo tee /sys/class/i2c-adapter/i2c-1/new_device
// echo grove_rgb 0x62 | sudo tee /sys/class/i2c-adapter/i2c-1/new_device
// Delete i2c device
// echo 0x3e | sudo tee /sys/class/i2c-adapter/i2c-1/delete_device
// echo 0x62 | sudo tee /sys/class/i2c-adapter/i2c-1/delete_device
// Test i2c
// i2cdetect -y 1

struct i2c_client *i2c_client_lcd;
struct i2c_client *i2c_client_rgb;

#define DEVICE_NAME "grove_lcd"
#define CLASS_NAME "grove_lcd_lcd"
static int majorNumber;
static struct class*  grove_lcd_class  = NULL;
static struct device* grove_lcd_device = NULL;
static int is_device_open = 0;



// --- Driver for display (grove_lcd) ----------------------------
static const struct i2c_device_id grove_lcd_id[] = {
    { "grove_lcd", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, grove_lcd_id);

static int grove_lcd_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    
    i2c_client_lcd = client;
    return 0;
}
 
static int grove_lcd_remove(struct i2c_client *client)
{
    return 0;
}

static struct i2c_driver grove_lcd_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "grove_lcd",
    },
    .probe          = grove_lcd_probe,
    .remove         = grove_lcd_remove,
    .id_table       = grove_lcd_id,
};

// --- Driver for LED (grove_rgb) --------------------------------
static const struct i2c_device_id grove_rgb_id[] = {
    { "grove_rgb", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, grove_rgb_id);

static int grove_rgb_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    i2c_client_rgb = client;
    lcd_begin();
    lcd_print("Grove_LCD start!");
    return 0;
}
 
static int grove_rgb_remove(struct i2c_client *client)
{
    return 0;
}

static struct i2c_driver grove_rgb_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "grove_rgb",
    },
    .probe          = grove_rgb_probe,
    .remove         = grove_rgb_remove,
    .id_table       = grove_rgb_id,
};

// --- Device ----------------------------------------------------

static int device_open( struct inode *inode, struct file *file )
{
    if ( is_device_open ) return -EBUSY;
	is_device_open++;
	return 0;
}

static int device_release( struct inode *inode, struct file *file )
{
    is_device_open--;
	return 0;
}

static ssize_t device_write(struct file *filp, const char *buff, size_t len, loff_t * offset)
{
    int i;    
    if (buff[0] == '@')
    {
        if (buff[1] == 'A') lcd_setColor(AQUA);
        if (buff[1] == 'B') lcd_setColor(BLUE);
        if (buff[1] == 'P') lcd_setColor(PURPLE);
        if (buff[1] == 'G') lcd_setColor(GREEN);
        if (buff[1] == 'R') lcd_setColor(RED);
        if (buff[1] == 'W') lcd_setColor(WHITE);
        if (buff[1] == 'Y') lcd_setColor(YELLOW);

        if (buff[1] == 'L')
        {
            if (buff[1] == '1') lcd_setCursor(0,1);
            if (buff[1] == '0') lcd_setCursor(0,0);
        }

        if (buff[1] == 'H') lcd_home();
        if (buff[1] == 'C') lcd_clear();
        return len;
    }
    for (i=0; i<len-1; i++)
    {
        lcd_write(buff[i]);
    }
    //printk(" --- buf: %s", buff);
	return len;
}

static ssize_t device_read( struct file *filp, char *buffer, size_t length, loff_t * offset )
{
    char ch[] = "Grove-LCD: Pleas print IN display.\n"; 
    printk (ch);
    //copy_to_user(buffer, ch, sizeof(ch));
    return 0;
}

static struct file_operations fops =
{
	.read = device_read,
	.write = device_write,
	.open = device_open,
	.release = device_release
};

// --- Init module -----------------------------------------------


static int __init grove_lcd_init(void) {
    printk("Grove-LCD: display modele - start.\n");
    majorNumber = register_chrdev(0, DEVICE_NAME, &fops);
    if (majorNumber<0){
        printk(KERN_ALERT "Grove-LCD: failed to register a major number\n");
        return majorNumber;
    }
    printk(KERN_INFO "Grove-LCD: registered correctly with major number %d\n", majorNumber);

    grove_lcd_class = class_create(THIS_MODULE, CLASS_NAME);
    if (IS_ERR(grove_lcd_class)){
        unregister_chrdev(majorNumber, DEVICE_NAME);
        printk(KERN_ALERT "Grove-LCD: Failed to register device class\n");
        return PTR_ERR(grove_lcd_class);
    }
    printk(KERN_INFO "Grove-LCD: device class registered correctly\n");

    grove_lcd_device = device_create(grove_lcd_class, NULL, MKDEV(majorNumber, 0), NULL, DEVICE_NAME);
    if (IS_ERR(grove_lcd_device)){ 
        class_destroy(grove_lcd_class);
        unregister_chrdev(majorNumber, DEVICE_NAME);
        printk(KERN_ALERT "Grove-LCD: Failed to create the device\n");
        return PTR_ERR(grove_lcd_device);
    }
    printk("Grove-LCD: device class created correctly\n");
    
    i2c_add_driver(&grove_lcd_driver);
    i2c_add_driver(&grove_rgb_driver);
    return 0;
}
static void __exit grove_lcd_exit(void) {

    device_destroy(grove_lcd_class, MKDEV(majorNumber, 0));
    class_unregister(grove_lcd_class);
    class_destroy(grove_lcd_class);
    unregister_chrdev(majorNumber, DEVICE_NAME);

    i2c_del_driver(&grove_lcd_driver);
    i2c_del_driver(&grove_rgb_driver);
    printk("Grove-LCD: display modele - kill.\n");
}


module_init(grove_lcd_init);
module_exit(grove_lcd_exit);



MODULE_LICENSE("GPL");
MODULE_AUTHOR("ZEN");