diff options
Diffstat (limited to 'Documentation/devicetree/bindings/leds/leds-aat1290.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/leds/leds-aat1290.txt | 73 |
1 files changed, 73 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 000000000..85c0c5861 --- /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-max-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-max-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>; + }; +}; |