74 lines
2.6 KiB
Plaintext
74 lines
2.6 KiB
Plaintext
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* Skyworks Solutions, Inc. AAT1290 Current Regulator for Flash LEDs
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The device is controlled through two pins: FL_EN and EN_SET. The pins when,
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asserted high, enable flash strobe and movie mode (max 1/2 of flash current)
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respectively. In order to add a capability of selecting the strobe signal source
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(e.g. CPU or camera sensor) there is an additional switch required, independent
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of the flash chip. The switch is controlled with pin control.
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Required properties:
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- compatible : Must be "skyworks,aat1290".
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- flen-gpios : Must be device tree identifier of the flash device FL_EN pin.
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- enset-gpios : Must be device tree identifier of the flash device EN_SET pin.
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Optional properties:
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- pinctrl-names : Must contain entries: "default", "host", "isp". Entries
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"default" and "host" must refer to the same pin configuration
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node, which sets the host as a strobe signal provider. Entry
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"isp" must refer to the pin configuration node, which sets the
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ISP as a strobe signal provider.
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A discrete LED element connected to the device must be represented by a child
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node - see Documentation/devicetree/bindings/leds/common.txt.
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Required properties of the LED child node:
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- led-max-microamp : see Documentation/devicetree/bindings/leds/common.txt
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- flash-max-microamp : see Documentation/devicetree/bindings/leds/common.txt
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Maximum flash LED supply current can be calculated using
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following formula: I = 1A * 162kohm / Rset.
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- flash-max-timeout-us : see Documentation/devicetree/bindings/leds/common.txt
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Maximum flash timeout can be calculated using following
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formula: T = 8.82 * 10^9 * Ct.
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Optional properties of the LED child node:
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- label : see Documentation/devicetree/bindings/leds/common.txt
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Example (by Ct = 220nF, Rset = 160kohm and exynos4412-trats2 board with
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a switch that allows for routing strobe signal either from the host or from
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the camera sensor):
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#include "exynos4412.dtsi"
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aat1290 {
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compatible = "skyworks,aat1290";
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flen-gpios = <&gpj1 1 GPIO_ACTIVE_HIGH>;
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enset-gpios = <&gpj1 2 GPIO_ACTIVE_HIGH>;
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pinctrl-names = "default", "host", "isp";
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pinctrl-0 = <&camera_flash_host>;
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pinctrl-1 = <&camera_flash_host>;
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pinctrl-2 = <&camera_flash_isp>;
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camera_flash: flash-led {
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label = "aat1290-flash";
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led-max-microamp = <520833>;
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flash-max-microamp = <1012500>;
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flash-max-timeout-us = <1940000>;
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};
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};
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&pinctrl_0 {
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camera_flash_host: camera-flash-host {
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samsung,pins = "gpj1-0";
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samsung,pin-function = <1>;
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samsung,pin-val = <0>;
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};
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camera_flash_isp: camera-flash-isp {
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samsung,pins = "gpj1-0";
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samsung,pin-function = <1>;
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samsung,pin-val = <1>;
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};
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};
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