/*
 * USB LED driver - 1.1
 *
 * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License as
 *      published by the Free Software Foundation, version 2.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>


#define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com"
#define DRIVER_DESC "USB LED Driver"

#define VENDOR_ID       0x0fc5
#define PRODUCT_ID      0x1223

/* table of devices that work with this driver */
static struct usb_device_id id_table [] = {
        { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
        { },
};
MODULE_DEVICE_TABLE (usb, id_table);

struct usb_led {
        struct usb_device *     udev;
        unsigned char           blue;
        unsigned char           red;
        unsigned char           green;
};

#define BLUE    0x04
#define RED     0x02
#define GREEN   0x01
static void change_color(struct usb_led *led)
{
        int retval;
        unsigned char color = 0x07;
        unsigned char *buffer;

        buffer = kmalloc(8, GFP_KERNEL);
        if (!buffer) {
                dev_err(&led->udev->dev, "out of memory\n");
                return;
        }

        if (led->blue)
                color &= ~(BLUE);
        if (led->red)
                color &= ~(RED);
        if (led->green)
                color &= ~(GREEN);
        dev_dbg(&led->udev->dev,
                "blue = %d, red = %d, green = %d, color = %.2x\n",
                led->blue, led->red, led->green, color);

        retval = usb_control_msg(led->udev,
                                usb_sndctrlpipe(led->udev, 0),
                                0x12,
                                0xc8,
                                (0x02 * 0x100) + 0x0a,
                                (0x00 * 0x100) + color,
                                buffer, 
                                8,
                                2000);
        if (retval)
                dev_dbg(&led->udev->dev, "retval = %d\n", retval);
        kfree(buffer);
}

#define show_set(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
{                                                                       \
        struct usb_interface *intf = to_usb_interface(dev);             \
        struct usb_led *led = usb_get_intfdata(intf);                   \
                                                                        \
        return sprintf(buf, "%d\n", led->value);                        \
}                                                                       \
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
{                                                                       \
        struct usb_interface *intf = to_usb_interface(dev);             \
        struct usb_led *led = usb_get_intfdata(intf);                   \
        int temp = simple_strtoul(buf, NULL, 10);                       \
                                                                        \
        led->value = temp;                                              \
        change_color(led);                                              \
        return count;                                                   \
}                                                                       \
static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
show_set(blue);
show_set(red);
show_set(green);

static int led_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(interface);
        struct usb_led *dev = NULL;
        int retval = -ENOMEM;

        dev = kzalloc(sizeof(struct usb_led), GFP_KERNEL);
        if (dev == NULL) {
                dev_err(&interface->dev, "Out of memory\n");
                goto error_mem;
        }

        dev->udev = usb_get_dev(udev);

        usb_set_intfdata (interface, dev);

        retval = device_create_file(&interface->dev, &dev_attr_blue);
        if (retval)
                goto error;
        retval = device_create_file(&interface->dev, &dev_attr_red);
        if (retval)
                goto error;
        retval = device_create_file(&interface->dev, &dev_attr_green);
        if (retval)
                goto error;

        dev_info(&interface->dev, "USB LED device now attached\n");
        return 0;

error:
        device_remove_file(&interface->dev, &dev_attr_blue);
        device_remove_file(&interface->dev, &dev_attr_red);
        device_remove_file(&interface->dev, &dev_attr_green);
        usb_set_intfdata (interface, NULL);
        usb_put_dev(dev->udev);
        kfree(dev);
error_mem:
        return retval;
}

static void led_disconnect(struct usb_interface *interface)
{
        struct usb_led *dev;

        dev = usb_get_intfdata (interface);

        device_remove_file(&interface->dev, &dev_attr_blue);
        device_remove_file(&interface->dev, &dev_attr_red);
        device_remove_file(&interface->dev, &dev_attr_green);

        /* first remove the files, then set the pointer to NULL */
        usb_set_intfdata (interface, NULL);

        usb_put_dev(dev->udev);

        kfree(dev);

        dev_info(&interface->dev, "USB LED now disconnected\n");
}

static struct usb_driver led_driver = {
        .name =         "usbled",
        .probe =        led_probe,
        .disconnect =   led_disconnect,
        .id_table =     id_table,
};

static int __init usb_led_init(void)
{
        int retval = 0;

        retval = usb_register(&led_driver);
        if (retval)
                err("usb_register failed. Error number %d", retval);
        return retval;
}

static void __exit usb_led_exit(void)
{
        usb_deregister(&led_driver);
}

module_init (usb_led_init);
module_exit (usb_led_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");