64 lines
2.2 KiB
Plaintext
64 lines
2.2 KiB
Plaintext
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>;
|
|
};
|