drivers/leds: Add module.h to files using it implicitly
[linux-2.6.git] / drivers / leds / dell-led.c
1 /*
2  * dell_led.c - Dell LED Driver
3  *
4  * Copyright (C) 2010 Dell Inc.
5  * Louis Davis <louis_davis@dell.com>
6  * Jim Dailey <jim_dailey@dell.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation.
11  *
12  */
13
14 #include <linux/acpi.h>
15 #include <linux/leds.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18
19 MODULE_AUTHOR("Louis Davis/Jim Dailey");
20 MODULE_DESCRIPTION("Dell LED Control Driver");
21 MODULE_LICENSE("GPL");
22
23 #define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
24 MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);
25
26 /* Error Result Codes: */
27 #define INVALID_DEVICE_ID       250
28 #define INVALID_PARAMETER       251
29 #define INVALID_BUFFER          252
30 #define INTERFACE_ERROR         253
31 #define UNSUPPORTED_COMMAND     254
32 #define UNSPECIFIED_ERROR       255
33
34 /* Device ID */
35 #define DEVICE_ID_PANEL_BACK    1
36
37 /* LED Commands */
38 #define CMD_LED_ON      16
39 #define CMD_LED_OFF     17
40 #define CMD_LED_BLINK   18
41
42 struct bios_args {
43         unsigned char length;
44         unsigned char result_code;
45         unsigned char device_id;
46         unsigned char command;
47         unsigned char on_time;
48         unsigned char off_time;
49 };
50
51 static int dell_led_perform_fn(u8 length,
52                 u8 result_code,
53                 u8 device_id,
54                 u8 command,
55                 u8 on_time,
56                 u8 off_time)
57 {
58         struct bios_args *bios_return;
59         u8 return_code;
60         union acpi_object *obj;
61         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
62         struct acpi_buffer input;
63         acpi_status status;
64
65         struct bios_args args;
66         args.length = length;
67         args.result_code = result_code;
68         args.device_id = device_id;
69         args.command = command;
70         args.on_time = on_time;
71         args.off_time = off_time;
72
73         input.length = sizeof(struct bios_args);
74         input.pointer = &args;
75
76         status = wmi_evaluate_method(DELL_LED_BIOS_GUID,
77                 1,
78                 1,
79                 &input,
80                 &output);
81
82         if (ACPI_FAILURE(status))
83                 return status;
84
85         obj = output.pointer;
86
87         if (!obj)
88                 return -EINVAL;
89         else if (obj->type != ACPI_TYPE_BUFFER) {
90                 kfree(obj);
91                 return -EINVAL;
92         }
93
94         bios_return = ((struct bios_args *)obj->buffer.pointer);
95         return_code = bios_return->result_code;
96
97         kfree(obj);
98
99         return return_code;
100 }
101
102 static int led_on(void)
103 {
104         return dell_led_perform_fn(3,   /* Length of command */
105                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
106                 DEVICE_ID_PANEL_BACK,   /* Device ID */
107                 CMD_LED_ON,             /* Command */
108                 0,                      /* not used */
109                 0);                     /* not used */
110 }
111
112 static int led_off(void)
113 {
114         return dell_led_perform_fn(3,   /* Length of command */
115                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
116                 DEVICE_ID_PANEL_BACK,   /* Device ID */
117                 CMD_LED_OFF,            /* Command */
118                 0,                      /* not used */
119                 0);                     /* not used */
120 }
121
122 static int led_blink(unsigned char on_eighths,
123                 unsigned char off_eighths)
124 {
125         return dell_led_perform_fn(5,   /* Length of command */
126                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
127                 DEVICE_ID_PANEL_BACK,   /* Device ID */
128                 CMD_LED_BLINK,          /* Command */
129                 on_eighths,             /* blink on in eigths of a second */
130                 off_eighths);           /* blink off in eights of a second */
131 }
132
133 static void dell_led_set(struct led_classdev *led_cdev,
134                 enum led_brightness value)
135 {
136         if (value == LED_OFF)
137                 led_off();
138         else
139                 led_on();
140 }
141
142 static int dell_led_blink(struct led_classdev *led_cdev,
143                 unsigned long *delay_on,
144                 unsigned long *delay_off)
145 {
146         unsigned long on_eighths;
147         unsigned long off_eighths;
148
149         /* The Dell LED delay is based on 125ms intervals.
150            Need to round up to next interval. */
151
152         on_eighths = (*delay_on + 124) / 125;
153         if (0 == on_eighths)
154                 on_eighths = 1;
155         if (on_eighths > 255)
156                 on_eighths = 255;
157         *delay_on = on_eighths * 125;
158
159         off_eighths = (*delay_off + 124) / 125;
160         if (0 == off_eighths)
161                 off_eighths = 1;
162         if (off_eighths > 255)
163                 off_eighths = 255;
164         *delay_off = off_eighths * 125;
165
166         led_blink(on_eighths, off_eighths);
167
168         return 0;
169 }
170
171 static struct led_classdev dell_led = {
172         .name           = "dell::lid",
173         .brightness     = LED_OFF,
174         .max_brightness = 1,
175         .brightness_set = dell_led_set,
176         .blink_set      = dell_led_blink,
177         .flags          = LED_CORE_SUSPENDRESUME,
178 };
179
180 static int __init dell_led_init(void)
181 {
182         int error = 0;
183
184         if (!wmi_has_guid(DELL_LED_BIOS_GUID))
185                 return -ENODEV;
186
187         error = led_off();
188         if (error != 0)
189                 return -ENODEV;
190
191         return led_classdev_register(NULL, &dell_led);
192 }
193
194 static void __exit dell_led_exit(void)
195 {
196         led_classdev_unregister(&dell_led);
197
198         led_off();
199 }
200
201 module_init(dell_led_init);
202 module_exit(dell_led_exit);