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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> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
54f4dedb | 17 | #include <linux/module.h> |
72dcd8d0 BR |
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); |