drivers/usb/misc/usbled.c

   1 /*
   2  * USB LED driver - 1.1
   3  *
   4  * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/usb.h>
  19
  20
  21 #define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com"
  22 #define DRIVER_DESC "USB LED Driver"
  23
  24 #define VENDOR_ID       0x0fc5
  25 #define PRODUCT_ID      0x1223
  26
  27 /* table of devices that work with this driver */
  28 static struct usb_device_id id_table [] = {
  29         { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
  30         { },
  31 };
  32 MODULE_DEVICE_TABLE (usb, id_table);
  33
  34 struct usb_led {
  35         struct usb_device *     udev;
  36         unsigned char           blue;
  37         unsigned char           red;
  38         unsigned char           green;
  39 };
  40
  41 #define BLUE    0x04
  42 #define RED     0x02
  43 #define GREEN   0x01
  44 static void change_color(struct usb_led *led)
  45 {
  46         int retval;
  47         unsigned char color = 0x07;
  48         unsigned char *buffer;
  49
  50         buffer = kmalloc(8, GFP_KERNEL);
  51         if (!buffer) {
  52                 dev_err(&led->udev->dev, "out of memory\n");
  53                 return;
  54         }
  55
  56         if (led->blue)
  57                 color &= ~(BLUE);
  58         if (led->red)
  59                 color &= ~(RED);
  60         if (led->green)
  61                 color &= ~(GREEN);
  62         dev_dbg(&led->udev->dev,
  63                 "blue = %d, red = %d, green = %d, color = %.2x\n",
  64                 led->blue, led->red, led->green, color);
  65
  66         retval = usb_control_msg(led->udev,
  67                                 usb_sndctrlpipe(led->udev, 0),
  68                                 0x12,
  69                                 0xc8,
  70                                 (0x02 * 0x100) + 0x0a,
  71                                 (0x00 * 0x100) + color,
  72                                 buffer,
  73                                 8,
  74                                 2000);
  75         if (retval)
  76                 dev_dbg(&led->udev->dev, "retval = %d\n", retval);
  77         kfree(buffer);
  78 }
  79
  80 #define show_set(value) \
  81 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
  82 {                                                                       \
  83         struct usb_interface *intf = to_usb_interface(dev);             \
  84         struct usb_led *led = usb_get_intfdata(intf);                   \
  85                                                                         \
  86         return sprintf(buf, "%d\n", led->value);                        \
  87 }                                                                       \
  88 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
  89 {                                                                       \
  90         struct usb_interface *intf = to_usb_interface(dev);             \
  91         struct usb_led *led = usb_get_intfdata(intf);                   \
  92         int temp = simple_strtoul(buf, NULL, 10);                       \
  93                                                                         \
  94         led->value = temp;                                              \
  95         change_color(led);                                              \
  96         return count;                                                   \
  97 }                                                                       \
  98 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
  99 show_set(blue);
 100 show_set(red);
 101 show_set(green);
 102
 103 static int led_probe(struct usb_interface *interface, const struct usb_device_id *id)
 104 {
 105         struct usb_device *udev = interface_to_usbdev(interface);
 106         struct usb_led *dev = NULL;
 107         int retval = -ENOMEM;
 108
 109         dev = kzalloc(sizeof(struct usb_led), GFP_KERNEL);
 110         if (dev == NULL) {
 111                 dev_err(&interface->dev, "Out of memory\n");
 112                 goto error;
 113         }
 114
 115         dev->udev = usb_get_dev(udev);
 116
 117         usb_set_intfdata (interface, dev);
 118
 119         device_create_file(&interface->dev, &dev_attr_blue);
 120         device_create_file(&interface->dev, &dev_attr_red);
 121         device_create_file(&interface->dev, &dev_attr_green);
 122
 123         dev_info(&interface->dev, "USB LED device now attached\n");
 124         return 0;
 125
 126 error:
 127         kfree(dev);
 128         return retval;
 129 }
 130
 131 static void led_disconnect(struct usb_interface *interface)
 132 {
 133         struct usb_led *dev;
 134
 135         dev = usb_get_intfdata (interface);
 136         usb_set_intfdata (interface, NULL);
 137
 138         device_remove_file(&interface->dev, &dev_attr_blue);
 139         device_remove_file(&interface->dev, &dev_attr_red);
 140         device_remove_file(&interface->dev, &dev_attr_green);
 141
 142         usb_put_dev(dev->udev);
 143
 144         kfree(dev);
 145
 146         dev_info(&interface->dev, "USB LED now disconnected\n");
 147 }
 148
 149 static struct usb_driver led_driver = {
 150         .name =         "usbled",
 151         .probe =        led_probe,
 152         .disconnect =   led_disconnect,
 153         .id_table =     id_table,
 154 };
 155
 156 static int __init usb_led_init(void)
 157 {
 158         int retval = 0;
 159
 160         retval = usb_register(&led_driver);
 161         if (retval)
 162                 err("usb_register failed. Error number %d", retval);
 163         return retval;
 164 }
 165
 166 static void __exit usb_led_exit(void)
 167 {
 168         usb_deregister(&led_driver);
 169 }
 170
 171 module_init (usb_led_init);
 172 module_exit (usb_led_exit);
 173
 174 MODULE_AUTHOR(DRIVER_AUTHOR);
 175 MODULE_DESCRIPTION(DRIVER_DESC);
 176 MODULE_LICENSE("GPL");