Texas Instruments OMAP compatible OPP supply description

OMAP5, DRA7, and AM57 family of SoCs have Class0 AVS eFuse registers which

contain data that can be used to adjust voltages programmed for some of their

supplies for more efficient operation. This binding provides the information

needed to read these values and use them to program the main regulator during

an OPP transitions.

Also, some supplies may have an associated vbb-supply which is an Adaptive Body

Bias regulator which much be transitioned in a specific sequence with regards

to the vdd-supply and clk when making an OPP transition. By supplying two

regulators to the device that will undergo OPP transitions we can make use

of the multi regulator binding that is part of the OPP core described here [1]

to describe both regulators needed by the platform.

[1] Documentation/devicetree/bindings/opp/opp.txt

Required Properties for Device Node:

- vdd-supply: phandle to regulator controlling VDD supply

- vbb-supply: phandle to regulator controlling Body Bias supply

(Usually Adaptive Body Bias regulator)

Required Properties for opp-supply node:

- compatible: Should be one of:

"ti,omap-opp-supply" - basic OPP supply controlling VDD and VBB

"ti,omap5-opp-supply" - OMAP5+ optimized voltages in efuse(class0)VDD

along with VBB

"ti,omap5-core-opp-supply" - OMAP5+ optimized voltages in efuse(class0) VDD

but no VBB.

- reg: Address and length of the efuse register set for the device (mandatory

only for "ti,omap5-opp-supply")

- ti,efuse-settings: An array of u32 tuple items providing information about

optimized efuse configuration. Each item consists of the following:

volt: voltage in uV - reference voltage (OPP voltage)

efuse_offseet: efuse offset from reg where the optimized voltage is stored.

- ti,absolute-max-voltage-uv: absolute maximum voltage for the OPP supply.

Example:

/* Device Node (CPU) */

cpus {

cpu0: cpu@0 {

device_type = "cpu";

...

vdd-supply = <&vcc>;

vbb-supply = <&abb_mpu>;

};

};

/* OMAP OPP Supply with Class0 registers */

opp_supply_mpu: opp_supply@4a003b20 {

compatible = "ti,omap5-opp-supply";

reg = <0x4a003b20 0x8>;

ti,efuse-settings = <

/* uV offset */

1060000 0x0

1160000 0x4

1210000 0x8

>;

ti,absolute-max-voltage-uv = <1500000>;

};