diff options
Diffstat (limited to 'Documentation/devicetree/bindings/leds/leds-lm3532.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/leds/leds-lm3532.txt | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/leds/leds-lm3532.txt b/Documentation/devicetree/bindings/leds/leds-lm3532.txt new file mode 100644 index 000000000..097490a5f --- /dev/null +++ b/Documentation/devicetree/bindings/leds/leds-lm3532.txt @@ -0,0 +1,105 @@ +* Texas Instruments - lm3532 White LED driver with ambient light sensing +capability. + +The LM3532 provides the 3 high-voltage, low-side current sinks. The device is +programmable over an I2C-compatible interface and has independent +current control for all three channels. The adaptive current regulation +method allows for different LED currents in each current sink thus allowing +for a wide variety of backlight and keypad applications. + +The main features of the LM3532 include dual ambient light sensor inputs +each with 32 internal voltage setting resistors, 8-bit logarithmic and linear +brightness control, dual external PWM brightness control inputs, and up to +1000:1 dimming ratio with programmable fade in and fade out settings. + +Required properties: + - compatible : "ti,lm3532" + - reg : I2C slave address + - #address-cells : 1 + - #size-cells : 0 + +Optional properties: + - enable-gpios : gpio pin to enable (active high)/disable the device. + - ramp-up-us - The Run time ramp rates/step are from one current + set-point to another after the device has reached its + initial target set point from turn-on + - ramp-down-us - The Run time ramp rates/step are from one current + set-point to another after the device has reached its + initial target set point from turn-on + Range for ramp settings: 8us - 65536us + +Optional properties if ALS mode is used: + - ti,als-vmin - Minimum ALS voltage defined in Volts + - ti,als-vmax - Maximum ALS voltage defined in Volts + Per the data sheet the max ALS voltage is 2V and the min is 0V + + - ti,als1-imp-sel - ALS1 impedance resistor selection in Ohms + - ti,als2-imp-sel - ALS2 impedance resistor selection in Ohms + Range for impedance select: 37000 Ohms - 1190 Ohms + Values above 37kohms will be set to the "High Impedance" setting + + - ti,als-avrg-time-us - Determines the length of time the device needs to + average the two ALS inputs. This is only used if + the input mode is LM3532_ALS_INPUT_AVRG. + Range: 17920us - 2293760us + - ti,als-input-mode - Determines how the device uses the attached ALS + devices. + 0x00 - ALS1 and ALS2 input average + 0x01 - ALS1 Input + 0x02 - ALS2 Input + 0x03 - Max of ALS1 and ALS2 + +Required child properties: + - reg : Indicates control bank the LED string is controlled by + - led-sources : see Documentation/devicetree/bindings/leds/common.txt + - ti,led-mode : Defines if the LED strings are manually controlled or + if the LED strings are controlled by the ALS. + 0x00 - LED strings are I2C controlled via full scale + brightness control register + 0x01 - LED strings are ALS controlled + +Optional LED child properties: + - label : see Documentation/devicetree/bindings/leds/common.txt + - linux,default-trigger : + see Documentation/devicetree/bindings/leds/common.txt + - led-max-microamp : Defines the full scale current value for each control + bank. The range is from 5000uA-29800uA in increments + of 800uA. + +Example: +led-controller@38 { + compatible = "ti,lm3532"; + #address-cells = <1>; + #size-cells = <0>; + reg = <0x38>; + + enable-gpios = <&gpio6 12 GPIO_ACTIVE_HIGH>; + ramp-up-us = <1024>; + ramp-down-us = <65536>; + + ti,als-vmin = <0>; + ti,als-vmax = <2000>; + ti,als1-imp-sel = <4110>; + ti,als2-imp-sel = <2180>; + ti,als-avrg-time-us = <17920>; + ti,als-input-mode = <0x00>; + + led@0 { + reg = <0>; + led-sources = <2>; + ti,led-mode = <1>; + led-max-microamp = <21800>; + label = ":backlight"; + linux,default-trigger = "backlight"; + }; + + led@1 { + reg = <1>; + led-sources = <1>; + ti,led-mode = <0>; + label = ":kbd_backlight"; + }; +}; + +For more product information please see the links below: +https://www.ti.com/product/LM3532 |