Add generic support for color LED's.
Basic idea is to use enum led_brightness also for the hue and saturation
color components.This allows to implement the color extension w/o
changes to struct led_classdev.
A driver that wants to use this extension has to select LEDS_HSV
in its Kconfig entry.
Flag LED_SET_HSV allows to specify that hue / saturation
should be overridden even if the provided values are zero.
Some examples for writing values to /sys/class/leds/<xx>/brightness:
(now also hex notation can be used)
255 -> set full brightness and keep existing color if set
0 -> switch LED off but keep existing color so that it can be restored
if the LED is switched on again later
0x1000000 -> switch LED off and set also hue and saturation to 0
0x00ffff -> set full brightness, full saturation and set hue to 0 (red)
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
v2:
- move extension-specific code into a separate source file and
introduce config symbol LEDS_HSV for it
- create separate patch for the extension to sysfs
- use variable name led_cdev as in the rest if the core
- rename to_hsv to led_validate_brightness
- rename LED_BRIGHTNESS_SET_COLOR to LED_SET_HSV
- introduce helper is_off for checking whether V part
of a HSV value is zero
---
drivers/leds/Kconfig | 5 +++++
drivers/leds/Makefile | 4 +++-
drivers/leds/led-core.c | 17 ++++++++++-------
drivers/leds/led-hsv-core.c | 30 ++++++++++++++++++++++++++++++
drivers/leds/leds.h | 17 +++++++++++++++++
include/linux/leds.h | 9 +++++++++
6 files changed, 74 insertions(+), 8 deletions(-)
create mode 100644 drivers/leds/led-hsv-core.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 7f940c2..01c0b35 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -29,6 +29,11 @@ config LEDS_CLASS_FLASH
for the flash related features of a LED device. It can be built
as a module.
+config LEDS_HSV
+ bool
+ depends on LEDS_CLASS
+ default n
+
comment "LED drivers"
config LEDS_88PM860X
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e9d5309..748d650 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -1,6 +1,8 @@
# LED Core
-obj-$(CONFIG_NEW_LEDS) += led-core.o
+obj-$(CONFIG_NEW_LEDS) += ledcore.o
+ledcore-y := led-core.o
+ledcore-$(CONFIG_LEDS_HSV) += led-hsv-core.o
obj-$(CONFIG_LEDS_CLASS) += led-class.o
obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 3495d5d..64b627a 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -62,7 +62,7 @@ static void led_timer_function(unsigned long data)
}
brightness = led_get_brightness(led_cdev);
- if (!brightness) {
+ if (is_off(brightness)) {
/* Time to switch the LED on. */
brightness = led_cdev->blink_brightness;
delay = led_cdev->blink_delay_on;
@@ -133,8 +133,8 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
if (current_brightness)
led_cdev->blink_brightness = current_brightness;
if (!led_cdev->blink_brightness)
- led_cdev->blink_brightness = led_cdev->max_brightness;
-
+ led_cdev->blink_brightness =
+ led_validate_brightness(led_cdev, LED_FULL);
led_cdev->blink_delay_on = delay_on;
led_cdev->blink_delay_off = delay_off;
@@ -225,6 +225,8 @@ EXPORT_SYMBOL_GPL(led_stop_software_blink);
void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
+ if (!(led_cdev->flags & LED_DEV_CAP_HSV))
+ brightness &= LED_BRIGHTNESS_MASK;
/*
* In case blinking is on delay brightness setting
* until the next timer tick.
@@ -235,12 +237,13 @@ void led_set_brightness(struct led_classdev *led_cdev,
* work queue task to avoid problems in case we are called
* from hard irq context.
*/
- if (brightness == LED_OFF) {
+ if (is_off(brightness)) {
led_cdev->flags |= LED_BLINK_DISABLE;
schedule_work(&led_cdev->set_brightness_work);
} else {
led_cdev->flags |= LED_BLINK_BRIGHTNESS_CHANGE;
- led_cdev->blink_brightness = brightness;
+ led_cdev->blink_brightness =
+ led_validate_brightness(led_cdev, brightness);
}
return;
}
@@ -265,7 +268,7 @@ EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
void led_set_brightness_nosleep(struct led_classdev *led_cdev,
enum led_brightness value)
{
- led_cdev->brightness = min(value, led_cdev->max_brightness);
+ led_cdev->brightness = led_validate_brightness(led_cdev, value);
if (led_cdev->flags & LED_SUSPENDED)
return;
@@ -280,7 +283,7 @@ int led_set_brightness_sync(struct led_classdev *led_cdev,
if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
return -EBUSY;
- led_cdev->brightness = min(value, led_cdev->max_brightness);
+ led_cdev->brightness = led_validate_brightness(led_cdev, value);
if (led_cdev->flags & LED_SUSPENDED)
return 0;
diff --git a/drivers/leds/led-hsv-core.c b/drivers/leds/led-hsv-core.c
new file mode 100644
index 0000000..3c31139
--- /dev/null
+++ b/drivers/leds/led-hsv-core.c
@@ -0,0 +1,30 @@
+/*
+ * LED Class Color Support
+ *
+ * Author: Heiner Kallweit <hkallweit1@xxxxxxxxx>
+ *
+ * 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/kernel.h>
+#include <linux/leds.h>
+#include "leds.h"
+
+#define LED_HUE_SAT_MASK 0x00ffff00
+
+enum led_brightness led_validate_brightness(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ enum led_brightness ret;
+
+ /* Use LED_SET_HSV to set hue and saturation even if both are zero */
+ if (value & LED_SET_HSV || value > LED_FULL)
+ ret = value & LED_HUE_SAT_MASK;
+ else
+ ret = led_cdev->brightness & ~LED_BRIGHTNESS_MASK;
+
+ return ret | min(value & LED_BRIGHTNESS_MASK, led_cdev->max_brightness);
+}
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index db3f20d..ac3f1be 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -16,17 +16,34 @@
#include <linux/rwsem.h>
#include <linux/leds.h>
+#define LED_BRIGHTNESS_MASK 0x000000ff
+
static inline int led_get_brightness(struct led_classdev *led_cdev)
{
return led_cdev->brightness;
}
+static inline bool is_off(enum led_brightness brightness)
+{
+ return (brightness & LED_BRIGHTNESS_MASK) == LED_OFF;
+}
+
void led_init_core(struct led_classdev *led_cdev);
void led_stop_software_blink(struct led_classdev *led_cdev);
void led_set_brightness_nopm(struct led_classdev *led_cdev,
enum led_brightness value);
void led_set_brightness_nosleep(struct led_classdev *led_cdev,
enum led_brightness value);
+#if IS_ENABLED(CONFIG_LEDS_HSV)
+enum led_brightness led_validate_brightness(struct led_classdev *led_cdev,
+ enum led_brightness value);
+#else
+static inline enum led_brightness led_validate_brightness(
+ struct led_classdev *led_cdev, enum led_brightness value)
+{
+ return min(value, led_cdev->max_brightness);
+}
+#endif
extern struct rw_semaphore leds_list_lock;
extern struct list_head leds_list;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index f203a8f..d72dfd9 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -29,8 +29,16 @@ enum led_brightness {
LED_OFF = 0,
LED_HALF = 127,
LED_FULL = 255,
+ /*
+ * dummy enum value to make gcc use a 32 bit type for the enum
+ * even if compiled with -fshort-enums. This is needed for
+ * the enum to store hsv values.
+ */
+ LED_SIZE_DUMMY = 0xffffffff,
};
+#define LED_SET_HSV BIT(24)
+
struct led_classdev {
const char *name;
enum led_brightness brightness;
@@ -50,6 +58,7 @@ struct led_classdev {
#define LED_SYSFS_DISABLE (1 << 22)
#define LED_DEV_CAP_FLASH (1 << 23)
#define LED_HW_PLUGGABLE (1 << 24)
+#define LED_DEV_CAP_HSV (1 << 25)
/* Set LED brightness level
* Must not sleep. Use brightness_set_blocking for drivers
--
2.7.1
--
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