drivers/leds/leds-hp-disk.c

   1 /*
   2  *  leds-hp-disk.c - driver for HP "hard disk protection" LED
   3  *
   4  *  Copyright (C) 2008 Pavel Machek
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/init.h>
  23 #include <linux/dmi.h>
  24 #include <linux/module.h>
  25 #include <linux/types.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/input.h>
  29 #include <linux/kthread.h>
  30 #include <linux/leds.h>
  31 #include <acpi/acpi_drivers.h>
  32
  33 #define DRIVER_NAME     "leds-hp-disk"
  34 #define ACPI_MDPS_CLASS "led"
  35
  36 /* For automatic insertion of the module */
  37 static struct acpi_device_id hpled_device_ids[] = {
  38         {"HPQ0004", 0}, /* HP Mobile Data Protection System PNP */
  39         {"", 0},
  40 };
  41 MODULE_DEVICE_TABLE(acpi, hpled_device_ids);
  42
  43 struct acpi_hpled {
  44         struct acpi_device      *device;   /* The ACPI device */
  45 };
  46
  47 static struct acpi_hpled adev;
  48
  49 static acpi_status hpled_acpi_write(acpi_handle handle, int reg)
  50 {
  51         unsigned long long ret; /* Not used when writing */
  52         union acpi_object in_obj[1];
  53         struct acpi_object_list args = { 1, in_obj };
  54
  55         in_obj[0].type          = ACPI_TYPE_INTEGER;
  56         in_obj[0].integer.value = reg;
  57
  58         return acpi_evaluate_integer(handle, "ALED", &args, &ret);
  59 }
  60
  61 static void hpled_set(struct led_classdev *led_cdev,
  62                                enum led_brightness value)
  63 {
  64         hpled_acpi_write(adev.device->handle, !!value);
  65 }
  66
  67 static struct led_classdev hpled_led = {
  68         .name                   = "hp:red:hddprotection",
  69         .default_trigger        = "heartbeat",
  70         .brightness_set         = hpled_set,
  71         .flags                  = LED_CORE_SUSPENDRESUME,
  72 };
  73
  74 static int hpled_add(struct acpi_device *device)
  75 {
  76         int ret;
  77
  78         if (!device)
  79                 return -EINVAL;
  80
  81         adev.device = device;
  82         strcpy(acpi_device_name(device), DRIVER_NAME);
  83         strcpy(acpi_device_class(device), ACPI_MDPS_CLASS);
  84         device->driver_data = &adev;
  85
  86         ret = led_classdev_register(NULL, &hpled_led);
  87         return ret;
  88 }
  89
  90 static int hpled_remove(struct acpi_device *device, int type)
  91 {
  92         if (!device)
  93                 return -EINVAL;
  94
  95         led_classdev_unregister(&hpled_led);
  96         return 0;
  97 }
  98
  99
 100
 101 static struct acpi_driver leds_hp_driver = {
 102         .name  = DRIVER_NAME,
 103         .class = ACPI_MDPS_CLASS,
 104         .ids   = hpled_device_ids,
 105         .ops = {
 106                 .add     = hpled_add,
 107                 .remove  = hpled_remove,
 108         }
 109 };
 110
 111 static int __init hpled_init_module(void)
 112 {
 113         int ret;
 114
 115         if (acpi_disabled)
 116                 return -ENODEV;
 117
 118         ret = acpi_bus_register_driver(&leds_hp_driver);
 119         if (ret < 0)
 120                 return ret;
 121
 122         printk(KERN_INFO DRIVER_NAME " driver loaded.\n");
 123
 124         return 0;
 125 }
 126
 127 static void __exit hpled_exit_module(void)
 128 {
 129         acpi_bus_unregister_driver(&leds_hp_driver);
 130 }
 131
 132 MODULE_DESCRIPTION("Driver for HP disk protection LED");
 133 MODULE_AUTHOR("Pavel Machek <pavel@suse.cz>");
 134 MODULE_LICENSE("GPL");
 135
 136 module_init(hpled_init_module);
 137 module_exit(hpled_exit_module);