Commit 6fd577cd authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'leds-for-4.20-rc1' of... 

Merge tag 'leds-for-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
"We introduce LED pattern trigger - the idea that was proposed three
 years ago now received enough attention and determination to drive it
 to the successful end.

  There is also one new LED class driver and couple of improvements to
  the existing ones.

  New LED class driver:
   - add support for Panasonic AN30259A with related DT bindings

  New LED trigger:
   - introduce LED pattern trigger

  leds-sc27xx-bltc:
   - implement pattern_set/clear ops to enable support for pattern
     trigger's hw_pattern sysfs file

  Improvements to existing LED class drivers:
   - leds-pwm: don't print error message on -EPROBE_DEFER
   - leds-gpio: try to lookup gpiod from device
   - leds-as3645a: convert to using %pOFn instead of device_node.name"

* tag 'leds-for-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: sc27xx: Add pattern_set/clear interfaces for LED controller
  leds: core: Introduce LED pattern trigger
  leds: add Panasonic AN30259A support
  dt-bindings: leds: document Panasonic AN30259A bindings
  leds: gpio: Try to lookup gpiod from device
  leds: pwm: silently error out on EPROBE_DEFER
  leds: Convert to using %pOFn instead of device_node.name
parents 114b5f8f 8dbac65f

Documentation/ABI/testing/sysfs-class-led-driver-sc27xx

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What:		/sys/class/leds/<led>/hw_pattern

Date:		September 2018

KernelVersion:	4.20

Description:

		Specify a hardware pattern for the SC27XX LED. For the SC27XX

		LED controller, it only supports 4 stages to make a single

		hardware pattern, which is used to configure the rise time,

		high time, fall time and low time for the breathing mode.



		For the breathing mode, the SC27XX LED only expects one brightness

		for the high stage. To be compatible with the hardware pattern

		format, we should set brightness as 0 for rise stage, fall

		stage and low stage.



		Min stage duration: 125 ms

		Max stage duration: 31875 ms



		Since the stage duration step is 125 ms, the duration should be

		a multiplier of 125, like 125ms, 250ms, 375ms, 500ms ... 31875ms.



		Thus the format of the hardware pattern values should be:

		"0 rise_duration brightness high_duration 0 fall_duration 0 low_duration".

Documentation/ABI/testing/sysfs-class-led-trigger-pattern

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What:		/sys/class/leds/<led>/pattern

Date:		September 2018

KernelVersion:	4.20

Description:

		Specify a software pattern for the LED, that supports altering

		the brightness for the specified duration with one software

		timer. It can do gradual dimming and step change of brightness.



		The pattern is given by a series of tuples, of brightness and

		duration (ms). The LED is expected to traverse the series and

		each brightness value for the specified duration. Duration of

		0 means brightness should immediately change to new value, and

		writing malformed pattern deactivates any active one.



		1. For gradual dimming, the dimming interval now is set as 50

		milliseconds. So the tuple with duration less than dimming

		interval (50ms) is treated as a step change of brightness,

		i.e. the subsequent brightness will be applied without adding

		intervening dimming intervals.



		The gradual dimming format of the software pattern values should be:

		"brightness_1 duration_1 brightness_2 duration_2 brightness_3

		duration_3 ...". For example:



		echo 0 1000 255 2000 > pattern



		It will make the LED go gradually from zero-intensity to max (255)

		intensity in 1000 milliseconds, then back to zero intensity in 2000

		milliseconds:



		LED brightness

		    ^

		255-|       / \            / \            /

		    |      /    \         /    \         /

		    |     /       \      /       \      /

		    |    /          \   /          \   /

		  0-|   /             \/             \/

		    +---0----1----2----3----4----5----6------------> time (s)



		2. To make the LED go instantly from one brigntess value to another,

		we should use use zero-time lengths (the brightness must be same as

		the previous tuple's). So the format should be:

		"brightness_1 duration_1 brightness_1 0 brightness_2 duration_2

		brightness_2 0 ...". For example:



		echo 0 1000 0 0 255 2000 255 0 > pattern



		It will make the LED stay off for one second, then stay at max brightness

		for two seconds:



		LED brightness

		    ^

		255-|        +---------+    +---------+

		    |        |         |    |         |

		    |        |         |    |         |

		    |        |         |    |         |

		  0-|   -----+         +----+         +----

		    +---0----1----2----3----4----5----6------------> time (s)



What:		/sys/class/leds/<led>/hw_pattern

Date:		September 2018

KernelVersion:	4.20

Description:

		Specify a hardware pattern for the LED, for LED hardware that

		supports autonomously controlling brightness over time, according

		to some preprogrammed hardware patterns. It deactivates any active

		software pattern.



		Since different LED hardware can have different semantics of

		hardware patterns, each driver is expected to provide its own

		description for the hardware patterns in their ABI documentation

		file.



What:		/sys/class/leds/<led>/repeat

Date:		September 2018

KernelVersion:	4.20

Description:

		Specify a pattern repeat number. -1 means repeat indefinitely,

		other negative numbers and number 0 are invalid.



		This file will always return the originally written repeat

		number.

Documentation/devicetree/bindings/leds/leds-an30259a.txt

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* Panasonic AN30259A 3-channel LED driver



The AN30259A is a LED controller capable of driving three LEDs independently. It supports

constant current output and sloping current output modes. The chip is connected over I2C.



Required properties:

	- compatible: Must be "panasonic,an30259a".

	- reg: I2C slave address.

	- #address-cells: Must be 1.

	- #size-cells: Must be 0.



Each LED is represented as a sub-node of the panasonic,an30259a node.



Required sub-node properties:

	- reg: Pin that the LED is connected to. Must be 1, 2, or 3.



Optional sub-node properties:

	- label: see Documentation/devicetree/bindings/leds/common.txt

	- linux,default-trigger: see Documentation/devicetree/bindings/leds/common.txt



Example:

led-controller@30 {

	compatible = "panasonic,an30259a";

	reg = <0x30>;

	#address-cells = <1>;

	#size-cells = <0>;



	led@1 {

		reg = <1>;

		linux,default-trigger = "heartbeat";

		label = "red:indicator";

	};



	led@2 {

		reg = <2>;

		label = "green:indicator";

	};



	led@3 {

		reg = <3>;

		label = "blue:indicator";

	};

};

drivers/leds/Kconfig

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@@ -58,6 +58,16 @@ config LEDS_AAT1290 
	help

	 This option enables support for the LEDs on the AAT1290.



config LEDS_AN30259A

	tristate "LED support for Panasonic AN30259A"

	depends on LEDS_CLASS && I2C && OF

	help

	  This option enables support for the AN30259A 3-channel

	  LED driver.



	  To compile this driver as a module, choose M here: the module

	  will be called leds-an30259a.



config LEDS_APU

	tristate "Front panel LED support for PC Engines APU/APU2/APU3 boards"

	depends on LEDS_CLASS

drivers/leds/Makefile

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@@ -11,6 +11,7 @@ obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o 
obj-$(CONFIG_LEDS_AAT1290)		+= leds-aat1290.o

obj-$(CONFIG_LEDS_APU)			+= leds-apu.o

obj-$(CONFIG_LEDS_AS3645A)		+= leds-as3645a.o

obj-$(CONFIG_LEDS_AN30259A)		+= leds-an30259a.o

obj-$(CONFIG_LEDS_BCM6328)		+= leds-bcm6328.o

obj-$(CONFIG_LEDS_BCM6358)		+= leds-bcm6358.o

obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o