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/leds.h> 16 #include <linux/list.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 #include <linux/rwsem.h> 20 #include "leds.h" 21 22 DECLARE_RWSEM(leds_list_lock); 23 EXPORT_SYMBOL_GPL(leds_list_lock); 24 25 LIST_HEAD(leds_list); 26 EXPORT_SYMBOL_GPL(leds_list); 27 28 static void led_set_software_blink(struct led_classdev *led_cdev, 29 unsigned long delay_on, 30 unsigned long delay_off) 31 { 32 int current_brightness; 33 34 current_brightness = led_get_brightness(led_cdev); 35 if (current_brightness) 36 led_cdev->blink_brightness = current_brightness; 37 if (!led_cdev->blink_brightness) 38 led_cdev->blink_brightness = led_cdev->max_brightness; 39 40 led_cdev->blink_delay_on = delay_on; 41 led_cdev->blink_delay_off = delay_off; 42 43 /* never on - just set to off */ 44 if (!delay_on) { 45 led_set_brightness_async(led_cdev, LED_OFF); 46 return; 47 } 48 49 /* never off - just set to brightness */ 50 if (!delay_off) { 51 led_set_brightness_async(led_cdev, led_cdev->blink_brightness); 52 return; 53 } 54 55 mod_timer(&led_cdev->blink_timer, jiffies + 1); 56 } 57 58 59 static void led_blink_setup(struct led_classdev *led_cdev, 60 unsigned long *delay_on, 61 unsigned long *delay_off) 62 { 63 if (!(led_cdev->flags & LED_BLINK_ONESHOT) && 64 led_cdev->blink_set && 65 !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 66 return; 67 68 /* blink with 1 Hz as default if nothing specified */ 69 if (!*delay_on && !*delay_off) 70 *delay_on = *delay_off = 500; 71 72 led_set_software_blink(led_cdev, *delay_on, *delay_off); 73 } 74 75 void led_blink_set(struct led_classdev *led_cdev, 76 unsigned long *delay_on, 77 unsigned long *delay_off) 78 { 79 del_timer_sync(&led_cdev->blink_timer); 80 81 led_cdev->flags &= ~LED_BLINK_ONESHOT; 82 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; 83 84 led_blink_setup(led_cdev, delay_on, delay_off); 85 } 86 EXPORT_SYMBOL(led_blink_set); 87 88 void led_blink_set_oneshot(struct led_classdev *led_cdev, 89 unsigned long *delay_on, 90 unsigned long *delay_off, 91 int invert) 92 { 93 if ((led_cdev->flags & LED_BLINK_ONESHOT) && 94 timer_pending(&led_cdev->blink_timer)) 95 return; 96 97 led_cdev->flags |= LED_BLINK_ONESHOT; 98 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; 99 100 if (invert) 101 led_cdev->flags |= LED_BLINK_INVERT; 102 else 103 led_cdev->flags &= ~LED_BLINK_INVERT; 104 105 led_blink_setup(led_cdev, delay_on, delay_off); 106 } 107 EXPORT_SYMBOL(led_blink_set_oneshot); 108 109 void led_stop_software_blink(struct led_classdev *led_cdev) 110 { 111 del_timer_sync(&led_cdev->blink_timer); 112 led_cdev->blink_delay_on = 0; 113 led_cdev->blink_delay_off = 0; 114 } 115 EXPORT_SYMBOL_GPL(led_stop_software_blink); 116 117 void led_set_brightness(struct led_classdev *led_cdev, 118 enum led_brightness brightness) 119 { 120 int ret = 0; 121 122 /* delay brightness if soft-blink is active */ 123 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) { 124 led_cdev->delayed_set_value = brightness; 125 if (brightness == LED_OFF) 126 schedule_work(&led_cdev->set_brightness_work); 127 return; 128 } 129 130 if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) { 131 led_set_brightness_async(led_cdev, brightness); 132 return; 133 } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC) 134 ret = led_set_brightness_sync(led_cdev, brightness); 135 else 136 ret = -EINVAL; 137 138 if (ret < 0) 139 dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n", 140 ret); 141 } 142 EXPORT_SYMBOL(led_set_brightness); 143 144 int led_update_brightness(struct led_classdev *led_cdev) 145 { 146 int ret = 0; 147 148 if (led_cdev->brightness_get) { 149 ret = led_cdev->brightness_get(led_cdev); 150 if (ret >= 0) { 151 led_cdev->brightness = ret; 152 return 0; 153 } 154 } 155 156 return ret; 157 } 158 EXPORT_SYMBOL(led_update_brightness); 159 160 /* Caller must ensure led_cdev->led_access held */ 161 void led_sysfs_disable(struct led_classdev *led_cdev) 162 { 163 lockdep_assert_held(&led_cdev->led_access); 164 165 led_cdev->flags |= LED_SYSFS_DISABLE; 166 } 167 EXPORT_SYMBOL_GPL(led_sysfs_disable); 168 169 /* Caller must ensure led_cdev->led_access held */ 170 void led_sysfs_enable(struct led_classdev *led_cdev) 171 { 172 lockdep_assert_held(&led_cdev->led_access); 173 174 led_cdev->flags &= ~LED_SYSFS_DISABLE; 175 } 176 EXPORT_SYMBOL_GPL(led_sysfs_enable); 177