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