[PATCH 2/3] leds: add LED Trigger for camera function

From: Kim, Milo
Date: Wed Feb 20 2013 - 03:37:00 EST


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@xxxxxx>
---
drivers/leds/trigger/Kconfig | 8 +++++
drivers/leds/trigger/Makefile | 1 +
drivers/leds/trigger/ledtrig-camera.c | 57 +++++++++++++++++++++++++++++++++
include/linux/leds.h | 8 +++++
4 files changed, 74 insertions(+)
create mode 100644 drivers/leds/trigger/ledtrig-camera.c

diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index eaa286d..49794b4 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -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
diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
index 554e46e..1abf48d 100644
--- a/drivers/leds/trigger/Makefile
+++ b/drivers/leds/trigger/Makefile
@@ -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
diff --git a/drivers/leds/trigger/ledtrig-camera.c b/drivers/leds/trigger/ledtrig-camera.c
new file mode 100644
index 0000000..9bd73a8
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-camera.c
@@ -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@xxxxxx>
+ *
+ * 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");
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 0d9b5ee..197ca9e 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -215,6 +215,14 @@ extern void ledtrig_ide_activity(void);
#define ledtrig_ide_activity() do {} while(0)
#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
+#define ledtrig_flash_ctrl(x) do {} while(0)
+#define ledtrig_torch_ctrl(x) do {} while(0)
+#endif
+
/*
* Generic LED platform data for describing LED names and default triggers.
*/
--
1.7.9.5


Best Regards,
Milo


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