Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds

Pull LED subsystem updates from Bryan Wu:
 "In this cycle, we finished to merge patches for LED Flash class
  driver.

  Other than that we have some bug fixes and new drivers for LED
  controllers"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (33 commits)
  leds:lp55xx: fix firmware loading error
  leds: fix max77693-led build errors
  leds: fix aat1290 build errors
  leds: aat1290: pass flags parameter to devm_gpiod_get
  leds: ktd2692: pass flags parameter to devm_gpiod_get
  drivers/leds: don't use module_init in non-modular leds-cobalt-raq.c
  leds: aat1290: add support for V4L2 Flash sub-device
  DT: aat1290: Document handling external strobe sources
  leds: max77693: add support for V4L2 Flash sub-device
  media: Add registration helpers for V4L2 flash sub-devices
  v4l: async: Add a pointer to of_node to struct v4l2_subdev, match it
  Documentation: leds: Add description of v4l2-flash sub-device
  leds: add BCM6358 LED driver
  leds: add DT binding for BCM6358 LED controller
  leds: fix brightness changing when software blinking is active
  Documentation: leds-lp5523: describe master fader attributes
  leds: lp5523: add master_fader support
  leds: leds-gpio: Allow compile test if !GPIOLIB
  leds: leds-gpio: Add missing #include <linux/of.h>
  gpiolib: Add missing dummies for the unified device properties interface
  ...

8 files changed, 699 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/leds/leds-aat1290.txt b/Documentation/devicetree/bindings/leds/leds-aat1290.txt
new file mode 100644
index 000000000000..c05ed91a4e42
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-aat1290.txt
@@ -0,0 +1,73 @@
+* Skyworks Solutions, Inc. AAT1290 Current Regulator for Flash LEDs
+
+The device is controlled through two pins: FL_EN and EN_SET. The pins when,
+asserted high, enable flash strobe and movie mode (max 1/2 of flash current)
+respectively. In order to add a capability of selecting the strobe signal source
+(e.g. CPU or camera sensor) there is an additional switch required, independent
+of the flash chip. The switch is controlled with pin control.
+
+Required properties:
+
+- compatible : Must be "skyworks,aat1290".
+- flen-gpios : Must be device tree identifier of the flash device FL_EN pin.
+- enset-gpios : Must be device tree identifier of the flash device EN_SET pin.
+
+Optional properties:
+- pinctrl-names : Must contain entries: "default", "host", "isp". Entries
+		"default" and "host" must refer to the same pin configuration
+		node, which sets the host as a strobe signal provider. Entry
+		"isp" must refer to the pin configuration node, which sets the
+		ISP as a strobe signal provider.
+
+A discrete LED element connected to the device must be represented by a child
+node - see Documentation/devicetree/bindings/leds/common.txt.
+
+Required properties of the LED child node:
+- led-max-microamp : see Documentation/devicetree/bindings/leds/common.txt
+- flash-max-microamp : see Documentation/devicetree/bindings/leds/common.txt
+                       Maximum flash LED supply current can be calculated using
+                       following formula: I = 1A * 162kohm / Rset.
+- flash-timeout-us : see Documentation/devicetree/bindings/leds/common.txt
+                     Maximum flash timeout can be calculated using following
+                     formula: T = 8.82 * 10^9 * Ct.
+
+Optional properties of the LED child node:
+- label : see Documentation/devicetree/bindings/leds/common.txt
+
+Example (by Ct = 220nF, Rset = 160kohm and exynos4412-trats2 board with
+a switch that allows for routing strobe signal either from the host or from
+the camera sensor):
+
+#include "exynos4412.dtsi"
+
+aat1290 {
+	compatible = "skyworks,aat1290";
+	flen-gpios = <&gpj1 1 GPIO_ACTIVE_HIGH>;
+	enset-gpios = <&gpj1 2 GPIO_ACTIVE_HIGH>;
+
+	pinctrl-names = "default", "host", "isp";
+	pinctrl-0 = <&camera_flash_host>;
+	pinctrl-1 = <&camera_flash_host>;
+	pinctrl-2 = <&camera_flash_isp>;
+
+	camera_flash: flash-led {
+		label = "aat1290-flash";
+		led-max-microamp = <520833>;
+		flash-max-microamp = <1012500>;
+		flash-timeout-us = <1940000>;
+	};
+};
+
+&pinctrl_0 {
+	camera_flash_host: camera-flash-host {
+		samsung,pins = "gpj1-0";
+		samsung,pin-function = <1>;
+		samsung,pin-val = <0>;
+	};
+
+	camera_flash_isp: camera-flash-isp {
+		samsung,pins = "gpj1-0";
+		samsung,pin-function = <1>;
+		samsung,pin-val = <1>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/leds/leds-bcm6328.txt b/Documentation/devicetree/bindings/leds/leds-bcm6328.txt
new file mode 100644
index 000000000000..f9e36adc0ebf
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-bcm6328.txt
@@ -0,0 +1,309 @@
+LEDs connected to Broadcom BCM6328 controller
+
+This controller is present on BCM6318, BCM6328, BCM6362 and BCM63268.
+In these SoCs it's possible to control LEDs both as GPIOs or by hardware.
+However, on some devices there are Serial LEDs (LEDs connected to a 74x164
+controller), which can either be controlled by software (exporting the 74x164
+as spi-gpio. See Documentation/devicetree/bindings/gpio/gpio-74x164.txt), or
+by hardware using this driver.
+Some of these Serial LEDs are hardware controlled (e.g. ethernet LEDs) and
+exporting the 74x164 as spi-gpio prevents those LEDs to be hardware
+controlled, so the only chance to keep them working is by using this driver.
+
+BCM6328 LED controller has a HWDIS register, which controls whether a LED
+should be controlled by a hardware signal instead of the MODE register value,
+with 0 meaning hardware control enabled and 1 hardware control disabled. This
+is usually 1:1 for hardware to LED signals, but through the activity/link
+registers you have some limited control over rerouting the LEDs (as
+explained later in brcm,link-signal-sources). Even if a LED is hardware
+controlled you are still able to make it blink or light it up if it isn't,
+but you can't turn it off if the hardware decides to light it up. For this
+reason, hardware controlled LEDs aren't registered as LED class devices.
+
+Required properties:
+  - compatible : should be "brcm,bcm6328-leds".
+  - #address-cells : must be 1.
+  - #size-cells : must be 0.
+  - reg : BCM6328 LED controller address and size.
+
+Optional properties:
+  - brcm,serial-leds : Boolean, enables Serial LEDs.
+    Default : false
+
+Each LED is represented as a sub-node of the brcm,bcm6328-leds device.
+
+LED sub-node required properties:
+  - reg : LED pin number (only LEDs 0 to 23 are valid).
+
+LED sub-node optional properties:
+  a) Optional properties for sub-nodes related to software controlled LEDs:
+    - label : see Documentation/devicetree/bindings/leds/common.txt
+    - active-low : Boolean, makes LED active low.
+      Default : false
+    - default-state : see
+      Documentation/devicetree/bindings/leds/leds-gpio.txt
+    - linux,default-trigger : see
+      Documentation/devicetree/bindings/leds/common.txt
+
+  b) Optional properties for sub-nodes related to hardware controlled LEDs:
+    - brcm,hardware-controlled : Boolean, makes this LED hardware controlled.
+      Default : false
+    - brcm,link-signal-sources : An array of hardware link
+      signal sources. Up to four link hardware signals can get muxed into
+      these LEDs. Only valid for LEDs 0 to 7, where LED signals 0 to 3 may
+      be muxed to LEDs 0 to 3, and signals 4 to 7 may be muxed to LEDs
+      4 to 7. A signal can be muxed to more than one LED, and one LED can
+      have more than one source signal.
+    - brcm,activity-signal-sources : An array of hardware activity
+      signal sources. Up to four activity hardware signals can get muxed into
+      these LEDs. Only valid for LEDs 0 to 7, where LED signals 0 to 3 may
+      be muxed to LEDs 0 to 3, and signals 4 to 7 may be muxed to LEDs
+      4 to 7. A signal can be muxed to more than one LED, and one LED can
+      have more than one source signal.
+
+Examples:
+Scenario 1 : BCM6328 with 4 EPHY LEDs
+	leds0: led-controller@10000800 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10000800 0x24>;
+
+		alarm_red@2 {
+			reg = <2>;
+			active-low;
+			label = "red:alarm";
+		};
+		inet_green@3 {
+			reg = <3>;
+			active-low;
+			label = "green:inet";
+		};
+		power_green@4 {
+			reg = <4>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+		ephy0_spd@17 {
+			reg = <17>;
+			brcm,hardware-controlled;
+		};
+		ephy1_spd@18 {
+			reg = <18>;
+			brcm,hardware-controlled;
+		};
+		ephy2_spd@19 {
+			reg = <19>;
+			brcm,hardware-controlled;
+		};
+		ephy3_spd@20 {
+			reg = <20>;
+			brcm,hardware-controlled;
+		};
+	};
+
+Scenario 2 : BCM63268 with Serial/GPHY0 LEDs
+	leds0: led-controller@10001900 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10001900 0x24>;
+		brcm,serial-leds;
+
+		gphy0_spd0@0 {
+			reg = <0>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <0>;
+		};
+		gphy0_spd1@1 {
+			reg = <1>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <1>;
+		};
+		inet_red@2 {
+			reg = <2>;
+			active-low;
+			label = "red:inet";
+		};
+		dsl_green@3 {
+			reg = <3>;
+			active-low;
+			label = "green:dsl";
+		};
+		usb_green@4 {
+			reg = <4>;
+			active-low;
+			label = "green:usb";
+		};
+		wps_green@7 {
+			reg = <7>;
+			active-low;
+			label = "green:wps";
+		};
+		inet_green@8 {
+			reg = <8>;
+			active-low;
+			label = "green:inet";
+		};
+		ephy0_act@9 {
+			reg = <9>;
+			brcm,hardware-controlled;
+		};
+		ephy1_act@10 {
+			reg = <10>;
+			brcm,hardware-controlled;
+		};
+		ephy2_act@11 {
+			reg = <11>;
+			brcm,hardware-controlled;
+		};
+		gphy0_act@12 {
+			reg = <12>;
+			brcm,hardware-controlled;
+		};
+		ephy0_spd@13 {
+			reg = <13>;
+			brcm,hardware-controlled;
+		};
+		ephy1_spd@14 {
+			reg = <14>;
+			brcm,hardware-controlled;
+		};
+		ephy2_spd@15 {
+			reg = <15>;
+			brcm,hardware-controlled;
+		};
+		power_green@20 {
+			reg = <20>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+	};
+
+Scenario 3 : BCM6362 with 1 LED for each EPHY
+	leds0: led-controller@10001900 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10001900 0x24>;
+
+		usb@0 {
+			reg = <0>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <0>;
+			brcm,activity-signal-sources = <0>;
+			/* USB link/activity routed to USB LED */
+		};
+		inet@1 {
+			reg = <1>;
+			brcm,hardware-controlled;
+			brcm,activity-signal-sources = <1>;
+			/* INET activity routed to INET LED */
+		};
+		ephy0@4 {
+			reg = <4>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <4>;
+			/* EPHY0 link routed to EPHY0 LED */
+		};
+		ephy1@5 {
+			reg = <5>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <5>;
+			/* EPHY1 link routed to EPHY1 LED */
+		};
+		ephy2@6 {
+			reg = <6>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <6>;
+			/* EPHY2 link routed to EPHY2 LED */
+		};
+		ephy3@7 {
+			reg = <7>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <7>;
+			/* EPHY3 link routed to EPHY3 LED */
+		};
+		power_green@20 {
+			reg = <20>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+	};
+
+Scenario 4 : BCM6362 with 1 LED for all EPHYs
+	leds0: led-controller@10001900 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10001900 0x24>;
+
+		usb@0 {
+			reg = <0>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <0 1>;
+			brcm,activity-signal-sources = <0 1>;
+			/* USB/INET link/activity routed to USB LED */
+		};
+		ephy@4 {
+			reg = <4>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <4 5 6 7>;
+			/* EPHY0/1/2/3 link routed to EPHY0 LED */
+		};
+		power_green@20 {
+			reg = <20>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+	};
+
+Scenario 5 : BCM6362 with EPHY LEDs swapped
+	leds0: led-controller@10001900 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10001900 0x24>;
+
+		usb@0 {
+			reg = <0>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <0>;
+			brcm,activity-signal-sources = <0 1>;
+			/* USB link/act and INET act routed to USB LED */
+		};
+		ephy0@4 {
+			reg = <4>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <7>;
+			/* EPHY3 link routed to EPHY0 LED */
+		};
+		ephy1@5 {
+			reg = <5>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <6>;
+			/* EPHY2 link routed to EPHY1 LED */
+		};
+		ephy2@6 {
+			reg = <6>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <5>;
+			/* EPHY1 link routed to EPHY2 LED */
+		};
+		ephy3@7 {
+			reg = <7>;
+			brcm,hardware-controlled;
+			brcm,link-signal-sources = <4>;
+			/* EPHY0 link routed to EPHY3 LED */
+		};
+		power_green@20 {
+			reg = <20>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+	};
diff --git a/Documentation/devicetree/bindings/leds/leds-bcm6358.txt b/Documentation/devicetree/bindings/leds/leds-bcm6358.txt
new file mode 100644
index 000000000000..b22a55bcc65d
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-bcm6358.txt
@@ -0,0 +1,145 @@
+LEDs connected to Broadcom BCM6358 controller
+
+This controller is present on BCM6358 and BCM6368.
+In these SoCs there are Serial LEDs (LEDs connected to a 74x164 controller),
+which can either be controlled by software (exporting the 74x164 as spi-gpio.
+See Documentation/devicetree/bindings/gpio/gpio-74x164.txt), or
+by hardware using this driver.
+
+Required properties:
+  - compatible : should be "brcm,bcm6358-leds".
+  - #address-cells : must be 1.
+  - #size-cells : must be 0.
+  - reg : BCM6358 LED controller address and size.
+
+Optional properties:
+  - brcm,clk-div : SCK signal divider. Possible values are 1, 2, 4 and 8.
+    Default : 1
+  - brcm,clk-dat-low : Boolean, makes clock and data signals active low.
+    Default : false
+
+Each LED is represented as a sub-node of the brcm,bcm6358-leds device.
+
+LED sub-node required properties:
+  - reg : LED pin number (only LEDs 0 to 31 are valid).
+
+LED sub-node optional properties:
+  - label : see Documentation/devicetree/bindings/leds/common.txt
+  - active-low : Boolean, makes LED active low.
+    Default : false
+  - default-state : see
+    Documentation/devicetree/bindings/leds/leds-gpio.txt
+  - linux,default-trigger : see
+    Documentation/devicetree/bindings/leds/common.txt
+
+Examples:
+Scenario 1 : BCM6358
+	leds0: led-controller@fffe00d0 {
+		compatible = "brcm,bcm6358-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0xfffe00d0 0x8>;
+
+		alarm_white {
+			reg = <0>;
+			active-low;
+			label = "white:alarm";
+		};
+		tv_white {
+			reg = <2>;
+			active-low;
+			label = "white:tv";
+		};
+		tel_white {
+			reg = <3>;
+			active-low;
+			label = "white:tel";
+		};
+		adsl_white {
+			reg = <4>;
+			active-low;
+			label = "white:adsl";
+		};
+	};
+
+Scenario 2 : BCM6368
+	leds0: led-controller@100000d0 {
+		compatible = "brcm,bcm6358-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x100000d0 0x8>;
+		brcm,pol-low;
+		brcm,clk-div = <4>;
+
+		power_red {
+			reg = <0>;
+			active-low;
+			label = "red:power";
+		};
+		power_green {
+			reg = <1>;
+			active-low;
+			label = "green:power";
+			default-state = "on";
+		};
+		power_blue {
+			reg = <2>;
+			label = "blue:power";
+		};
+		broadband_red {
+			reg = <3>;
+			active-low;
+			label = "red:broadband";
+		};
+		broadband_green {
+			reg = <4>;
+			label = "green:broadband";
+		};
+		broadband_blue {
+			reg = <5>;
+			active-low;
+			label = "blue:broadband";
+		};
+		wireless_red {
+			reg = <6>;
+			active-low;
+			label = "red:wireless";
+		};
+		wireless_green {
+			reg = <7>;
+			active-low;
+			label = "green:wireless";
+		};
+		wireless_blue {
+			reg = <8>;
+			label = "blue:wireless";
+		};
+		phone_red {
+			reg = <9>;
+			active-low;
+			label = "red:phone";
+		};
+		phone_green {
+			reg = <10>;
+			active-low;
+			label = "green:phone";
+		};
+		phone_blue {
+			reg = <11>;
+			label = "blue:phone";
+		};
+		upgrading_red {
+			reg = <12>;
+			active-low;
+			label = "red:upgrading";
+		};
+		upgrading_green {
+			reg = <13>;
+			active-low;
+			label = "green:upgrading";
+		};
+		upgrading_blue {
+			reg = <14>;
+			label = "blue:upgrading";
+		};
+	};
diff --git a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
new file mode 100644
index 000000000000..853737452580
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
@@ -0,0 +1,50 @@
+* Kinetic Technologies - KTD2692 Flash LED Driver
+
+KTD2692 is the ideal power solution for high-power flash LEDs.
+It uses ExpressWire single-wire programming for maximum flexibility.
+
+The ExpressWire interface through CTRL pin can control LED on/off and
+enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
+Flash timeout, LVP(low voltage protection).
+
+Also, When the AUX pin is pulled high while CTRL pin is high,
+LED current will be ramped up to the flash-mode current level.
+
+Required properties:
+- compatible : Should be "kinetic,ktd2692".
+- ctrl-gpios : Specifier of the GPIO connected to CTRL pin.
+- aux-gpios : Specifier of the GPIO connected to AUX pin.
+
+Optional properties:
+- vin-supply : "vin" LED supply (2.7V to 5.5V).
+  See Documentation/devicetree/bindings/regulator/regulator.txt
+
+A discrete LED element connected to the device must be represented by a child
+node - See Documentation/devicetree/bindings/leds/common.txt
+
+Required properties for flash LED child nodes:
+  See Documentation/devicetree/bindings/leds/common.txt
+- led-max-microamp : Minimum Threshold for Timer protection
+  is defined internally (Maximum 300mA).
+- flash-max-microamp : Flash LED maximum current
+  Formula : I(mA) = 15000 / Rset.
+- flash-max-timeout-us : Flash LED maximum timeout.
+
+Optional properties for flash LED child nodes:
+- label : See Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+ktd2692 {
+	compatible = "kinetic,ktd2692";
+	ctrl-gpios = <&gpc0 1 0>;
+	aux-gpios = <&gpc0 2 0>;
+	vin-supply = <&vbat>;
+
+	flash-led {
+		label = "ktd2692-flash";
+		led-max-microamp = <300000>;
+		flash-max-microamp = <1500000>;
+		flash-max-timeout-us = <1835000>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/leds/leds-tlc591xx.txt b/Documentation/devicetree/bindings/leds/leds-tlc591xx.txt
new file mode 100644
index 000000000000..3bbbf7024411
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-tlc591xx.txt
@@ -0,0 +1,40 @@
+LEDs connected to tlc59116 or tlc59108
+
+Required properties
+- compatible: should be "ti,tlc59116" or "ti,tlc59108"
+- #address-cells: must be 1
+- #size-cells: must be 0
+- reg: typically 0x68
+
+Each led is represented as a sub-node of the ti,tlc59116.
+See Documentation/devicetree/bindings/leds/common.txt
+
+LED sub-node properties:
+- reg: number of LED line, 0 to 15 or 0 to 7
+- label: (optional) name of LED
+- linux,default-trigger : (optional)
+
+Examples:
+
+tlc59116@68 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	compatible = "ti,tlc59116";
+	reg = <0x68>;
+
+	wan@0 {
+		label = "wrt1900ac:amber:wan";
+		reg = <0x0>;
+	};
+
+	2g@2 {
+		label = "wrt1900ac:white:2g";
+		reg = <0x2>;
+	};
+
+	alive@9 {
+		label = "wrt1900ac:green:alive";
+		reg = <0x9>;
+		linux,default_trigger = "heartbeat";
+	};
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 7b607761b774..347c8fdcf250 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -114,6 +114,7 @@ isee	ISEE 2007 S.L.
 isil	Intersil
 karo	Ka-Ro electronics GmbH
 keymile	Keymile GmbH
+kinetic Kinetic Technologies
 lacie	LaCie
 lantiq	Lantiq Semiconductor
 lenovo	Lenovo Group Ltd.
diff --git a/Documentation/leds/leds-class-flash.txt b/Documentation/leds/leds-class-flash.txt
index 19bb67355424..8da3c6f4b60b 100644
--- a/Documentation/leds/leds-class-flash.txt
+++ b/Documentation/leds/leds-class-flash.txt
@@ -20,3 +20,54 @@ Following sysfs attributes are exposed for controlling flash LED devices:
 	- max_flash_timeout
 	- flash_strobe
 	- flash_fault
+
+
+V4L2 flash wrapper for flash LEDs
+=================================
+
+A LED subsystem driver can be controlled also from the level of VideoForLinux2
+subsystem. In order to enable this CONFIG_V4L2_FLASH_LED_CLASS symbol has to
+be defined in the kernel config.
+
+The driver must call the v4l2_flash_init function to get registered in the
+V4L2 subsystem. The function takes six arguments:
+- dev       : flash device, e.g. an I2C device
+- of_node   : of_node of the LED, may be NULL if the same as device's
+- fled_cdev : LED flash class device to wrap
+- iled_cdev : LED flash class device representing indicator LED associated with
+	      fled_cdev, may be NULL
+- ops : V4L2 specific ops
+	* external_strobe_set - defines the source of the flash LED strobe -
+		V4L2_CID_FLASH_STROBE control or external source, typically
+		a sensor, which makes it possible to synchronise the flash
+		strobe start with exposure start,
+	* intensity_to_led_brightness and led_brightness_to_intensity - perform
+		enum led_brightness <-> V4L2 intensity conversion in a device
+		specific manner - they can be used for devices with non-linear
+		LED current scale.
+- config : configuration for V4L2 Flash sub-device
+	* dev_name - the name of the media entity, unique in the system,
+	* flash_faults - bitmask of flash faults that the LED flash class
+		device can report; corresponding LED_FAULT* bit definitions are
+		available in <linux/led-class-flash.h>,
+	* torch_intensity - constraints for the LED in TORCH mode
+		in microamperes,
+	* indicator_intensity - constraints for the indicator LED
+		in microamperes,
+	* has_external_strobe - determines whether the flash strobe source
+		can be switched to external,
+
+On remove the v4l2_flash_release function has to be called, which takes one
+argument - struct v4l2_flash pointer returned previously by v4l2_flash_init.
+This function can be safely called with NULL or error pointer argument.
+
+Please refer to drivers/leds/leds-max77693.c for an exemplary usage of the
+v4l2 flash wrapper.
+
+Once the V4L2 sub-device is registered by the driver which created the Media
+controller device, the sub-device node acts just as a node of a native V4L2
+flash API device would. The calls are simply routed to the LED flash API.
+
+Opening the V4L2 flash sub-device makes the LED subsystem sysfs interface
+unavailable. The interface is re-enabled after the V4L2 flash sub-device
+is closed.
diff --git a/Documentation/leds/leds-lp5523.txt b/Documentation/leds/leds-lp5523.txt
index 5b3e91d4ac59..0dbbd279c9b9 100644
--- a/Documentation/leds/leds-lp5523.txt
+++ b/Documentation/leds/leds-lp5523.txt
@@ -49,6 +49,36 @@ There are two ways to run LED patterns.
 2) Firmware interface - LP55xx common interface
   For the details, please refer to 'firmware' section in leds-lp55xx.txt
 
+LP5523 has three master faders. If a channel is mapped to one of
+the master faders, its output is dimmed based on the value of the master
+fader.
+
+For example,
+
+  echo "123000123" > master_fader_leds
+
+creates the following channel-fader mappings:
+
+  channel 0,6 to master_fader1
+  channel 1,7 to master_fader2
+  channel 2,8 to master_fader3
+
+Then, to have 25% of the original output on channel 0,6:
+
+  echo 64 > master_fader1
+
+To have 0% of the original output (i.e. no output) channel 1,7:
+
+  echo 0 > master_fader2
+
+To have 100% of the original output (i.e. no dimming) on channel 2,8:
+
+  echo 255 > master_fader3
+
+To clear all master fader controls:
+
+  echo "000000000" > master_fader_leds
+
 Selftest uses always the current from the platform data.
 
 Each channel contains led current settings.