https://github.com/torvalds/linux
Tip revision: 74fca6a42863ffacaf7ba6f1936a9f228950f657 authored by Linus Torvalds on 09 September 2009, 22:13:59 UTC
Linux 2.6.31
Linux 2.6.31
Tip revision: 74fca6a
usbled.c
/*
* 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");