1 /* 2 * LED Class Core 3 * 4 * Copyright 2005-2006 Openedhand Ltd. 5 * 6 * Author: Richard Purdie <rpurdie@openedhand.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 version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/list.h> 16 #include <linux/module.h> 17 #include <linux/rwsem.h> 18 #include <linux/leds.h> 19 #include "leds.h" 20 21 DECLARE_RWSEM(leds_list_lock); 22 EXPORT_SYMBOL_GPL(leds_list_lock); 23 24 LIST_HEAD(leds_list); 25 EXPORT_SYMBOL_GPL(leds_list); 26 27 static void led_stop_software_blink(struct led_classdev *led_cdev) 28 { 29 /* deactivate previous settings */ 30 del_timer_sync(&led_cdev->blink_timer); 31 led_cdev->blink_delay_on = 0; 32 led_cdev->blink_delay_off = 0; 33 } 34 35 static void led_set_software_blink(struct led_classdev *led_cdev, 36 unsigned long delay_on, 37 unsigned long delay_off) 38 { 39 int current_brightness; 40 41 current_brightness = led_get_brightness(led_cdev); 42 if (current_brightness) 43 led_cdev->blink_brightness = current_brightness; 44 if (!led_cdev->blink_brightness) 45 led_cdev->blink_brightness = led_cdev->max_brightness; 46 47 if (led_get_trigger_data(led_cdev) && 48 delay_on == led_cdev->blink_delay_on && 49 delay_off == led_cdev->blink_delay_off) 50 return; 51 52 led_stop_software_blink(led_cdev); 53 54 led_cdev->blink_delay_on = delay_on; 55 led_cdev->blink_delay_off = delay_off; 56 57 /* never on - don't blink */ 58 if (!delay_on) 59 return; 60 61 /* never off - just set to brightness */ 62 if (!delay_off) { 63 led_set_brightness(led_cdev, led_cdev->blink_brightness); 64 return; 65 } 66 67 mod_timer(&led_cdev->blink_timer, jiffies + 1); 68 } 69 70 71 void led_blink_set(struct led_classdev *led_cdev, 72 unsigned long *delay_on, 73 unsigned long *delay_off) 74 { 75 del_timer_sync(&led_cdev->blink_timer); 76 77 if (led_cdev->blink_set && 78 !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 79 return; 80 81 /* blink with 1 Hz as default if nothing specified */ 82 if (!*delay_on && !*delay_off) 83 *delay_on = *delay_off = 500; 84 85 led_set_software_blink(led_cdev, *delay_on, *delay_off); 86 } 87 EXPORT_SYMBOL(led_blink_set); 88 89 void led_brightness_set(struct led_classdev *led_cdev, 90 enum led_brightness brightness) 91 { 92 led_stop_software_blink(led_cdev); 93 led_cdev->brightness_set(led_cdev, brightness); 94 } 95 EXPORT_SYMBOL(led_brightness_set); 96