dt-bindings: backlight: Add DT bindings for qcom-spmi-wled driver

Bindings for Qualcomm Technologies, Inc. WLED driver

WLED (White Light Emitting Diode) driver is used for controlling display

backlight that is part of PMIC on Qualcomm Technologies, Inc. reference

platforms. The PMIC is connected to the host processor via SPMI bus.

- compatible

	Usage:      required

	Value type: <string>

	Definition: should be one of the below.

			"qcom,pmi8998-spmi-wled",

			"qcom,pm8150l-spmi-wled",

			"qcom,pm6150l-spmi-wled"

			"qcom,pm660l-spmi-wled"

- reg

	Usage:      required

	Value type: <prop-encoded-array>

	Definition:  Base address and size of the WLED modules.

- reg-names

	Usage:      required

	Value type: <string>

	Definition:  Names associated with base addresses. should be

		     "wled-ctrl-base", "wled-sink-base".

- interrupts

	Usage:      optional

	Value type: <prop encoded array>

	Definition: Interrupts associated with WLED. Interrupts can be

		    specified as per the encoding listed under

		    Documentation/devicetree/bindings/spmi/

		    qcom,spmi-pmic-arb.txt.

- interrupt-names

	Usage:      optional

	Value type: <string>

	Definition: Interrupt names associated with the interrupts.

		    Currently supported interrupts are "sc-irq", "ovp-irq",

		    "pre-flash-irq" and "flash-irq". Pre_flash and flash

		    interrupts can be specified only for PMICs that has WLED5.

- label

	Usage:      required

	Value type: <string>

	Definition: The name of the backlight device.

- default-brightness

	Usage:      optional

	Value type: <u32>

	Definition: Brightness value on boot. Default is 2048.

		    Range of values are:

		    For pmi8998, it is 0-4095.

		    For pm8150l, this can vary from 0-4095 or 0-32767 depending

		    on the brightness control mode. If CABC is enabled, 0-4095

		    range is used.

- max-brightness

	Usage:      optional

	Value type: <u32>

	Definition: Maximum brightness level. Allowed values are:

		    For pmi8998, it is 4095.

		    For pm8150l, this can be either 4095 or 32767.

		    If CABC is enabled, this is capped to 4095.

- qcom,fs-current-limit

	Usage:      optional

	Value type: <u32>

	Definition: per-string full scale current limit in uA. value from

		    0 to 30000 with 5000 uA resolution. Default: 25000 uA

- qcom,boost-current-limit

	Usage:      optional

	Value type: <u32>

	Definition: ILIM threshold in mA. values are 105, 280, 450, 620, 970,

		    1150, 1300, 1500. Default: 970 mA

- qcom,switching-freq

	Usage:      optional

	Value type: <u32>

	Definition: Switching frequency in KHz. values are

		    600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371,

		    1600, 1920, 2400, 3200, 4800, 9600.

		    Default: 800 KHz

- qcom,ovp

	Usage:      optional

	Value type: <u32>

	Definition: Over-voltage protection limit in mV. values are 31100,

		    29600, 19600, 18100.

	            Default: 29600 mV

- qcom,string-cfg

	Usage:      optional

	Value type: <u32>

	Definition: Bit mask of the WLED strings. Bit 0 to 3 indicates strings

		    0 to 3 respectively. WLED module has four strings of leds

		    numbered from 0 to 3. Each string of leds are operated

		    individually. Specify the strings using the bit mask. Any

		    combination of led strings can be used.

		    Default value is 15 (b1111).

- qcom,en-cabc

	Usage:      optional

	Value type: <bool>

	Definition: Specify if cabc (content adaptive backlight control) is

		    needed.

- qcom,ext-pfet-sc-pro-en

	Usage:      optional

	Value type: <bool>

	Definition: Specify if external PFET control for short circuit

		    protection is needed. This is not applicable for PM8150L.

- qcom,auto-calibration

	Usage:      optional

	Value type: <bool>

	Definition: Enables auto-calibration of the WLED sink configuration.

- qcom,modulator-sel

	Usage:      optional

	Value type: <u32>

	Definition: Selects the modulator used for brightness modulation.

		    Allowed values are:

		    0 - Modulator A

		    1 - Modulator B

		    If not specified, then modulator A will be used by default.

		    This property is applicable only to WLED5 peripheral.

- qcom,cabc-sel

	Usage:      optional

	Value type: <u32>

	Definition: Selects the CABC pin signal used for brightness modulation.

		    Allowed values are:

		    0 - CABC disabled

		    1 - CABC 1

		    2 - CABC 2

		    3 - External signal (e.g. LPG) is used for dimming

		    This property is applicable only to WLED5 peripheral.

- qcom,pmic-revid

	Usage:      optional

	Value type: <phandle>

	Definition: If specified, can be used to get PMIC revision information.

- qcom,leds-per-string

	Usage:      optional

	Value type: <u32>

	Definition: If specified, can be used to calculate available current

		    during selfie flash operation. If not specified, available

		    current calculated is simply the configured threshold.

Following properties are for child subnodes that are needed for WLED preflash

(or torch), flash and switch. These child subnodes can be specified only for

PMICs that has WLED5 (e.g. PM8150L).

For wled_torch child subnode,

- label

	Usage:      required

	Value type: <string>

	Definition: Should be "torch".

- qcom,default-led-trigger

	Usage:      optional

	Value type: <string>

	Definition: Name for LED trigger. If unspecified, "wled_torch" is used.

- qcom,wled-torch-fsc

	Usage:      optional

	Value type: <u32>

	Definition: WLED torch full scale current in mA. This configures the

		    maximum current allowed for torch device. Allowed values

		    are from 5 to 60 mA with a step of 5 mA. If not specified,

		    default value is set to 30 mA.

- qcom,wled-torch-step

	Usage:      optional

	Value type: <u32>

	Definition: WLED torch step delay in us. This configures the step delay

		    when the output is ramped up to the desired target current.

		    Allowed values are from 50 to 400 us with a step of 50 us.

		    If not specified, default value is set to 200 us.

- qcom,wled-torch-timer

	Usage:      optional

	Value type: <u32>

	Definition: WLED torch safety timer in ms. This configures the safety

		    timer to turn off torch automatically after timer expiry.

		    Allowed values are: 50, 100, 200, 400, 600, 800, 1000 and

		    1200. If not specified, default value is set to 1200 ms.

For wled_flash child subnode,

- label

	Usage:      required

	Value type: <string>

	Definition: Should be "flash".

- qcom,default-led-trigger

	Usage:      optional

	Value type: <string>

	Definition: Name for LED trigger. If unspecified, "wled_flash" is used.

- qcom,wled-flash-fsc

	Usage:      optional

	Value type: <u32>

	Definition: WLED flash full scale current in mA. This configures the

		    maximum current allowed for flash device. Allowed values

		    are from 5 to 60 mA with a step of 5 mA. If not specified,

		    default value is set to 40 mA.

- qcom,wled-flash-step

	Usage:      optional

	Value type: <u32>

	Definition: WLED flash step delay in us. This configures the step delay

		    when the output is ramped up to the desired target current.

		    Allowed values are from 50 to 400 us with a step of 50 us.

		    If not specified, default value is set to 200 us.

- qcom,wled-flash-timer

	Usage:      optional

	Value type: <u32>

	Definition: WLED flash safety timer in ms. This configures the safety

		    timer to turn off flash automatically after timer expiry.

		    Allowed values are: 50, 100, 200, 400, 600, 800, 1000 and

		    1200. If not specified, default value is set to 100 ms.

For wled_switch child subnode,

- label

	Usage:      required

	Value type: <string>

	Definition: Should be "switch".

- qcom,default-led-trigger

	Usage:      optional

	Value type: <string>

	Definition: Name for LED trigger. If unspecified, "wled_switch" is

		    used.

Example:

qcom-wled@d800 {

	compatible = "qcom,pmi8998-spmi-wled";

	#address-cells = <1>;

	#size-cells = <0>;

	reg = <0xd800 0xd900>;

	reg-names = "wled-ctrl-base", "wled-sink-base";

	label = "backlight";

	interrupts = <0x3 0xd8 0x2 IRQ_TYPE_EDGE_RISING>,

			<0x3 0xd8 0x1 IRQ_TYPE_EDGE_RISING>;

	interrupt-names = "sc-irq", "ovp-irq";

	qcom,fs-current-limit = <25000>;

	qcom,boost-current-limit = <970>;

	qcom,switching-freq = <800>;

	qcom,ovp = <29600>;

	qcom,string-cfg = <15>;

};

qcom-wled@d800 {

	compatible = "qcom,pm8150l-spmi-wled";

	#address-cells = <2>;

	#size-cells = <0>;

	reg = <0xd800 0x100>, <0xd900 0x100>;

	reg-names = "wled-ctrl-base", "wled-sink-base";

	label = "backlight";

	interrupts = <0x5 0xd8 0x1 IRQ_TYPE_EDGE_RISING>;

	interrupt-names = "ovp-irq";

	qcom,string-cfg = <7>;

	wled_torch: qcom,wled-torch {

		label = "torch";

		qcom,wled-torch-fsc = <40>;

		qcom,wled-torch-step = <300>;

		qcom,wled-torch-timer = <600>;

	};

	wled_flash: qcom,wled-flash {

		label = "flash";

		qcom,wled-flash-fsc = <60>;

		qcom,wled-flash-step = <100>;

		qcom,wled-flash-timer = <200>;

	};

	wled_switch: qcom,wled-switch {

		label = "switch";

	};

};

qcom,leds@d800 {

	compatible = "qcom,pm660l-spmi-wled";

	reg = <0xd800 0x100>,

		<0xd900 0x100>;

	reg-names = "qpnp-wled-ctrl-base",

	"qpnp-wled-sink-base";

	interrupts = <0x3 0xd8 0x1 IRQ_TYPE_EDGE_RISING>;

	interrupt-names = "ovp-irq";

	linux,name = "wled";

	linux,default-led-trigger = "bkl-trigger";

};