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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/leds/dell-led.c
2 * dell_led.c - Dell LED Driver
4 * Copyright (C) 2010 Dell Inc.
5 * Louis Davis <louis_davis@dell.com>
6 * Jim Dailey <jim_dailey@dell.com>
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.
14 #include <linux/acpi.h>
15 #include <linux/leds.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
19 MODULE_AUTHOR("Louis Davis/Jim Dailey");
20 MODULE_DESCRIPTION("Dell LED Control Driver");
21 MODULE_LICENSE("GPL");
23 #define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
24 MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID
);
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
35 #define DEVICE_ID_PANEL_BACK 1
39 #define CMD_LED_OFF 17
40 #define CMD_LED_BLINK 18
44 unsigned char result_code
;
45 unsigned char device_id
;
46 unsigned char command
;
47 unsigned char on_time
;
48 unsigned char off_time
;
51 static int dell_led_perform_fn(u8 length
,
58 struct bios_args
*bios_return
;
60 union acpi_object
*obj
;
61 struct acpi_buffer output
= { ACPI_ALLOCATE_BUFFER
, NULL
};
62 struct acpi_buffer input
;
65 struct bios_args args
;
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
;
73 input
.length
= sizeof(struct bios_args
);
74 input
.pointer
= &args
;
76 status
= wmi_evaluate_method(DELL_LED_BIOS_GUID
,
82 if (ACPI_FAILURE(status
))
89 else if (obj
->type
!= ACPI_TYPE_BUFFER
) {
94 bios_return
= ((struct bios_args
*)obj
->buffer
.pointer
);
95 return_code
= bios_return
->result_code
;
102 static int led_on(void)
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 */
112 static int led_off(void)
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 */
122 static int led_blink(unsigned char on_eighths
,
123 unsigned char off_eighths
)
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 */
133 static void dell_led_set(struct led_classdev
*led_cdev
,
134 enum led_brightness value
)
136 if (value
== LED_OFF
)
142 static int dell_led_blink(struct led_classdev
*led_cdev
,
143 unsigned long *delay_on
,
144 unsigned long *delay_off
)
146 unsigned long on_eighths
;
147 unsigned long off_eighths
;
149 /* The Dell LED delay is based on 125ms intervals.
150 Need to round up to next interval. */
152 on_eighths
= (*delay_on
+ 124) / 125;
155 if (on_eighths
> 255)
157 *delay_on
= on_eighths
* 125;
159 off_eighths
= (*delay_off
+ 124) / 125;
160 if (0 == off_eighths
)
162 if (off_eighths
> 255)
164 *delay_off
= off_eighths
* 125;
166 led_blink(on_eighths
, off_eighths
);
171 static struct led_classdev dell_led
= {
173 .brightness
= LED_OFF
,
175 .brightness_set
= dell_led_set
,
176 .blink_set
= dell_led_blink
,
177 .flags
= LED_CORE_SUSPENDRESUME
,
180 static int __init
dell_led_init(void)
184 if (!wmi_has_guid(DELL_LED_BIOS_GUID
))
191 return led_classdev_register(NULL
, &dell_led
);
194 static void __exit
dell_led_exit(void)
196 led_classdev_unregister(&dell_led
);
201 module_init(dell_led_init
);
202 module_exit(dell_led_exit
);