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/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/module.h>
  17 #include <linux/usb.h>
  18
  19
  20 #define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com"
  21 #define DRIVER_DESC "USB LED Driver"
  22
  23 #define VENDOR_ID       0x0fc5
  24 #define PRODUCT_ID      0x1223
  25
  26 /* table of devices that work with this driver */
  27 static struct usb_device_id id_table [] = {
  28         { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
  29         { },
  30 };
  31 MODULE_DEVICE_TABLE (usb, id_table);
  32
  33 struct usb_led {
  34         struct usb_device *     udev;
  35         unsigned char           blue;
  36         unsigned char           red;
  37         unsigned char           green;
  38 };
  39
  40 #define BLUE    0x04
  41 #define RED     0x02
  42 #define GREEN   0x01
  43 static void change_color(struct usb_led *led)
  44 {
  45         int retval;
  46         unsigned char color = 0x07;
  47         unsigned char *buffer;
  48
  49         buffer = kmalloc(8, GFP_KERNEL);
  50         if (!buffer) {
  51                 dev_err(&led->udev->dev, "out of memory\n");
  52                 return;
  53         }
  54
  55         if (led->blue)
  56                 color &= ~(BLUE);
  57         if (led->red)
  58                 color &= ~(RED);
  59         if (led->green)
  60                 color &= ~(GREEN);
  61         dev_dbg(&led->udev->dev,
  62                 "blue = %d, red = %d, green = %d, color = %.2x\n",
  63                 led->blue, led->red, led->green, color);
  64
  65         retval = usb_control_msg(led->udev,
  66                                 usb_sndctrlpipe(led->udev, 0),
  67                                 0x12,
  68                                 0xc8,
  69                                 (0x02 * 0x100) + 0x0a,
  70                                 (0x00 * 0x100) + color,
  71                                 buffer,
  72                                 8,
  73                                 2000);
  74         if (retval)
  75                 dev_dbg(&led->udev->dev, "retval = %d\n", retval);
  76         kfree(buffer);
  77 }
  78
  79 #define show_set(value) \
  80 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
  81 {                                                                       \
  82         struct usb_interface *intf = to_usb_interface(dev);             \
  83         struct usb_led *led = usb_get_intfdata(intf);                   \
  84                                                                         \
  85         return sprintf(buf, "%d\n", led->value);                        \
  86 }                                                                       \
  87 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
  88 {                                                                       \
  89         struct usb_interface *intf = to_usb_interface(dev);             \
  90         struct usb_led *led = usb_get_intfdata(intf);                   \
  91         int temp = simple_strtoul(buf, NULL, 10);                       \
  92                                                                         \
  93         led->value = temp;                                              \
  94         change_color(led);                                              \
  95         return count;                                                   \
  96 }                                                                       \
  97 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
  98 show_set(blue);
  99 show_set(red);
 100 show_set(green);
 101
 102 static int led_probe(struct usb_interface *interface, const struct usb_device_id *id)
 103 {
 104         struct usb_device *udev = interface_to_usbdev(interface);
 105         struct usb_led *dev = NULL;
 106         int retval = -ENOMEM;
 107
 108         dev = kzalloc(sizeof(struct usb_led), GFP_KERNEL);
 109         if (dev == NULL) {
 110                 dev_err(&interface->dev, "Out of memory\n");
 111                 goto error_mem;
 112         }
 113
 114         dev->udev = usb_get_dev(udev);
 115
 116         usb_set_intfdata (interface, dev);
 117
 118         retval = device_create_file(&interface->dev, &dev_attr_blue);
 119         if (retval)
 120                 goto error;
 121         retval = device_create_file(&interface->dev, &dev_attr_red);
 122         if (retval)
 123                 goto error;
 124         retval = device_create_file(&interface->dev, &dev_attr_green);
 125         if (retval)
 126                 goto error;
 127
 128         dev_info(&interface->dev, "USB LED device now attached\n");
 129         return 0;
 130
 131 error:
 132         device_remove_file(&interface->dev, &dev_attr_blue);
 133         device_remove_file(&interface->dev, &dev_attr_red);
 134         device_remove_file(&interface->dev, &dev_attr_green);
 135         usb_set_intfdata (interface, NULL);
 136         usb_put_dev(dev->udev);
 137         kfree(dev);
 138 error_mem:
 139         return retval;
 140 }
 141
 142 static void led_disconnect(struct usb_interface *interface)
 143 {
 144         struct usb_led *dev;
 145
 146         dev = usb_get_intfdata (interface);
 147
 148         device_remove_file(&interface->dev, &dev_attr_blue);
 149         device_remove_file(&interface->dev, &dev_attr_red);
 150         device_remove_file(&interface->dev, &dev_attr_green);
 151
 152         /* first remove the files, then set the pointer to NULL */
 153         usb_set_intfdata (interface, NULL);
 154
 155         usb_put_dev(dev->udev);
 156
 157         kfree(dev);
 158
 159         dev_info(&interface->dev, "USB LED now disconnected\n");
 160 }
 161
 162 static struct usb_driver led_driver = {
 163         .name =         "usbled",
 164         .probe =        led_probe,
 165         .disconnect =   led_disconnect,
 166         .id_table =     id_table,
 167 };
 168
 169 static int __init usb_led_init(void)
 170 {
 171         int retval = 0;
 172
 173         retval = usb_register(&led_driver);
 174         if (retval)
 175                 err("usb_register failed. Error number %d", retval);
 176         return retval;
 177 }
 178
 179 static void __exit usb_led_exit(void)
 180 {
 181         usb_deregister(&led_driver);
 182 }
 183
 184 module_init (usb_led_init);
 185 module_exit (usb_led_exit);
 186
 187 MODULE_AUTHOR(DRIVER_AUTHOR);
 188 MODULE_DESCRIPTION(DRIVER_DESC);
 189 MODULE_LICENSE("GPL");