blob: 52590296af33e4a3f3af3b5de975741c3ffb1fc4 [file] [log] [blame]
Bob Rodgers72dcd8d2010-02-17 15:23:31 -06001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Bob Rodgers72dcd8d2010-02-17 15:23:31 -060017
18MODULE_AUTHOR("Louis Davis/Jim Dailey");
19MODULE_DESCRIPTION("Dell LED Control Driver");
20MODULE_LICENSE("GPL");
21
22#define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
23MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);
24
25/* Error Result Codes: */
26#define INVALID_DEVICE_ID 250
27#define INVALID_PARAMETER 251
28#define INVALID_BUFFER 252
29#define INTERFACE_ERROR 253
30#define UNSUPPORTED_COMMAND 254
31#define UNSPECIFIED_ERROR 255
32
33/* Device ID */
34#define DEVICE_ID_PANEL_BACK 1
35
36/* LED Commands */
37#define CMD_LED_ON 16
38#define CMD_LED_OFF 17
39#define CMD_LED_BLINK 18
40
41struct bios_args {
42 unsigned char length;
43 unsigned char result_code;
44 unsigned char device_id;
45 unsigned char command;
46 unsigned char on_time;
47 unsigned char off_time;
48};
49
50static int dell_led_perform_fn(u8 length,
51 u8 result_code,
52 u8 device_id,
53 u8 command,
54 u8 on_time,
55 u8 off_time)
56{
57 struct bios_args *bios_return;
58 u8 return_code;
59 union acpi_object *obj;
60 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
61 struct acpi_buffer input;
62 acpi_status status;
63
64 struct bios_args args;
65 args.length = length;
66 args.result_code = result_code;
67 args.device_id = device_id;
68 args.command = command;
69 args.on_time = on_time;
70 args.off_time = off_time;
71
72 input.length = sizeof(struct bios_args);
73 input.pointer = &args;
74
75 status = wmi_evaluate_method(DELL_LED_BIOS_GUID,
76 1,
77 1,
78 &input,
79 &output);
80
81 if (ACPI_FAILURE(status))
82 return status;
83
84 obj = output.pointer;
85
86 if (!obj)
87 return -EINVAL;
88 else if (obj->type != ACPI_TYPE_BUFFER) {
89 kfree(obj);
90 return -EINVAL;
91 }
92
93 bios_return = ((struct bios_args *)obj->buffer.pointer);
94 return_code = bios_return->result_code;
95
96 kfree(obj);
97
98 return return_code;
99}
100
101static int led_on(void)
102{
103 return dell_led_perform_fn(3, /* Length of command */
104 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */
105 DEVICE_ID_PANEL_BACK, /* Device ID */
106 CMD_LED_ON, /* Command */
107 0, /* not used */
108 0); /* not used */
109}
110
111static int led_off(void)
112{
113 return dell_led_perform_fn(3, /* Length of command */
114 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */
115 DEVICE_ID_PANEL_BACK, /* Device ID */
116 CMD_LED_OFF, /* Command */
117 0, /* not used */
118 0); /* not used */
119}
120
121static int led_blink(unsigned char on_eighths,
122 unsigned char off_eighths)
123{
124 return dell_led_perform_fn(5, /* Length of command */
125 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */
126 DEVICE_ID_PANEL_BACK, /* Device ID */
127 CMD_LED_BLINK, /* Command */
128 on_eighths, /* blink on in eigths of a second */
129 off_eighths); /* blink off in eights of a second */
130}
131
132static void dell_led_set(struct led_classdev *led_cdev,
133 enum led_brightness value)
134{
135 if (value == LED_OFF)
136 led_off();
137 else
138 led_on();
139}
140
141static int dell_led_blink(struct led_classdev *led_cdev,
142 unsigned long *delay_on,
143 unsigned long *delay_off)
144{
145 unsigned long on_eighths;
146 unsigned long off_eighths;
147
148 /* The Dell LED delay is based on 125ms intervals.
149 Need to round up to next interval. */
150
151 on_eighths = (*delay_on + 124) / 125;
152 if (0 == on_eighths)
153 on_eighths = 1;
154 if (on_eighths > 255)
155 on_eighths = 255;
156 *delay_on = on_eighths * 125;
157
158 off_eighths = (*delay_off + 124) / 125;
159 if (0 == off_eighths)
160 off_eighths = 1;
161 if (off_eighths > 255)
162 off_eighths = 255;
163 *delay_off = off_eighths * 125;
164
165 led_blink(on_eighths, off_eighths);
166
167 return 0;
168}
169
170static struct led_classdev dell_led = {
171 .name = "dell::lid",
172 .brightness = LED_OFF,
173 .max_brightness = 1,
174 .brightness_set = dell_led_set,
175 .blink_set = dell_led_blink,
176 .flags = LED_CORE_SUSPENDRESUME,
177};
178
179static int __init dell_led_init(void)
180{
181 int error = 0;
182
183 if (!wmi_has_guid(DELL_LED_BIOS_GUID))
184 return -ENODEV;
185
186 error = led_off();
187 if (error != 0)
188 return -ENODEV;
189
190 return led_classdev_register(NULL, &dell_led);
191}
192
193static void __exit dell_led_exit(void)
194{
195 led_classdev_unregister(&dell_led);
196
197 led_off();
198}
199
200module_init(dell_led_init);
201module_exit(dell_led_exit);