projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 132e9306 RG |
1 | /* |
| 2 | * Backlight emulation LED trigger | |
| 3 | * | |
| 4 | * Copyright 2008 (C) Rodolfo Giometti <giometti@linux.it> | |
| 5 | * Copyright 2008 (C) Eurotech S.p.A. <info@eurotech.it> | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | * | |
| 11 | */ | |
| 12 | ||
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/kernel.h> | |
| 15 | #include <linux/init.h> | |
| 16 | #include <linux/fb.h> | |
| 17 | #include <linux/leds.h> | |
| 18 | #include "leds.h" | |
| 19 | ||
| 20 | #define BLANK 1 | |
| 21 | #define UNBLANK 0 | |
| 22 | ||
| 23 | struct bl_trig_notifier { | |
| 24 | struct led_classdev *led; | |
| 25 | int brightness; | |
| 26 | int old_status; | |
| 27 | struct notifier_block notifier; | |
| 28 | }; | |
| 29 | ||
| 30 | static int fb_notifier_callback(struct notifier_block *p, | |
| 31 | unsigned long event, void *data) | |
| 32 | { | |
| 33 | struct bl_trig_notifier *n = container_of(p, | |
| 34 | struct bl_trig_notifier, notifier); | |
| 35 | struct led_classdev *led = n->led; | |
| 36 | struct fb_event *fb_event = data; | |
| 37 | int *blank = fb_event->data; | |
| 38 | ||
| 39 | switch (event) { | |
| 40 | case FB_EVENT_BLANK : | |
| 41 | if (*blank && n->old_status == UNBLANK) { | |
| 42 | n->brightness = led->brightness; | |
| 43 | led_set_brightness(led, LED_OFF); | |
| 44 | n->old_status = BLANK; | |
| 45 | } else if (!*blank && n->old_status == BLANK) { | |
| 46 | led_set_brightness(led, n->brightness); | |
| 47 | n->old_status = UNBLANK; | |
| 48 | } | |
| 49 | break; | |
| 50 | } | |
| 51 | ||
| 52 | return 0; | |
| 53 | } | |
| 54 | ||
| 55 | static void bl_trig_activate(struct led_classdev *led) | |
| 56 | { | |
| 57 | int ret; | |
| 58 | ||
| 59 | struct bl_trig_notifier *n; | |
| 60 | ||
| 61 | n = kzalloc(sizeof(struct bl_trig_notifier), GFP_KERNEL); | |
| 62 | led->trigger_data = n; | |
| 63 | if (!n) { | |
| 64 | dev_err(led->dev, "unable to allocate backlight trigger\n"); | |
| 65 | return; | |
| 66 | } | |
| 67 | ||
| 68 | n->led = led; | |
| 69 | n->brightness = led->brightness; | |
| 70 | n->old_status = UNBLANK; | |
| 71 | n->notifier.notifier_call = fb_notifier_callback; | |
| 72 | ||
| 73 | ret = fb_register_client(&n->notifier); | |
| 74 | if (ret) | |
| 75 | dev_err(led->dev, "unable to register backlight trigger\n"); | |
| 76 | } | |
| 77 | ||
| 78 | static void bl_trig_deactivate(struct led_classdev *led) | |
| 79 | { | |
| 80 | struct bl_trig_notifier *n = | |
| 81 | (struct bl_trig_notifier *) led->trigger_data; | |
| 82 | ||
| 83 | if (n) { | |
| 84 | fb_unregister_client(&n->notifier); | |
| 85 | kfree(n); | |
| 86 | } | |
| 87 | } | |
| 88 | ||
| 89 | static struct led_trigger bl_led_trigger = { | |
| 90 | .name = "backlight", | |
| 91 | .activate = bl_trig_activate, | |
| 92 | .deactivate = bl_trig_deactivate | |
| 93 | }; | |
| 94 | ||
| 95 | static int __init bl_trig_init(void) | |
| 96 | { | |
| 97 | return led_trigger_register(&bl_led_trigger); | |
| 98 | } | |
| 99 | ||
| 100 | static void __exit bl_trig_exit(void) | |
| 101 | { | |
| 102 | led_trigger_unregister(&bl_led_trigger); | |
| 103 | } | |
| 104 | ||
| 105 | module_init(bl_trig_init); | |
| 106 | module_exit(bl_trig_exit); | |
| 107 | ||
| 108 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
| 109 | MODULE_DESCRIPTION("Backlight emulation LED trigger"); | |
| 110 | MODULE_LICENSE("GPL v2"); |