leds: add camera LED triggers

Some LED devices support flash/torch functionality through the LED subsystem.
This patch enables direct LED trigger controls by the driver.
Flash on/off and torch on/off can be done simply by other driver space.
Two trigger APIs are added, ledtrig_flash_ctrl() and ledtrig_torch_ctrl().

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
This commit is contained in:
Kim, Milo 2013-03-14 04:29:24 -07:00 committed by Bryan Wu
parent 39f7e08af3
commit 48a1d032c9
4 changed files with 74 additions and 0 deletions

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@ -100,4 +100,12 @@ config LEDS_TRIGGER_TRANSIENT
GPIO/PWM based hardware.
If unsure, say Y.
config LEDS_TRIGGER_CAMERA
tristate "LED Camera Flash/Torch Trigger"
depends on LEDS_TRIGGERS
help
This allows LEDs to be controlled as a camera flash/torch device.
This enables direct flash/torch on/off by the driver, kernel space.
If unsure, say Y.
endif # LEDS_TRIGGERS

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@ -7,3 +7,4 @@ obj-$(CONFIG_LEDS_TRIGGER_GPIO) += ledtrig-gpio.o
obj-$(CONFIG_LEDS_TRIGGER_CPU) += ledtrig-cpu.o
obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o
obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT) += ledtrig-transient.o
obj-$(CONFIG_LEDS_TRIGGER_CAMERA) += ledtrig-camera.o

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@ -0,0 +1,57 @@
/*
* Camera Flash and Torch On/Off Trigger
*
* based on ledtrig-ide-disk.c
*
* Copyright 2013 Texas Instruments
*
* Author: Milo(Woogyom) Kim <milo.kim@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/leds.h>
DEFINE_LED_TRIGGER(ledtrig_flash);
DEFINE_LED_TRIGGER(ledtrig_torch);
void ledtrig_flash_ctrl(bool on)
{
enum led_brightness brt = on ? LED_FULL : LED_OFF;
led_trigger_event(ledtrig_flash, brt);
}
EXPORT_SYMBOL_GPL(ledtrig_flash_ctrl);
void ledtrig_torch_ctrl(bool on)
{
enum led_brightness brt = on ? LED_FULL : LED_OFF;
led_trigger_event(ledtrig_torch, brt);
}
EXPORT_SYMBOL_GPL(ledtrig_torch_ctrl);
static int __init ledtrig_camera_init(void)
{
led_trigger_register_simple("flash", &ledtrig_flash);
led_trigger_register_simple("torch", &ledtrig_torch);
return 0;
}
module_init(ledtrig_camera_init);
static void __exit ledtrig_camera_exit(void)
{
led_trigger_unregister_simple(ledtrig_torch);
led_trigger_unregister_simple(ledtrig_flash);
}
module_exit(ledtrig_camera_exit);
MODULE_DESCRIPTION("LED Trigger for Camera Flash/Torch Control");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");

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@ -218,6 +218,14 @@ extern void ledtrig_ide_activity(void);
static inline void ledtrig_ide_activity(void) {}
#endif
#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
extern void ledtrig_flash_ctrl(bool on);
extern void ledtrig_torch_ctrl(bool on);
#else
static inline void ledtrig_flash_ctrl(bool on) {}
static inline void ledtrig_torch_ctrl(bool on) {}
#endif
/*
* Generic LED platform data for describing LED names and default triggers.
*/