xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/power/mali-opp.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)

# SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
#
# (C) COPYRIGHT 2017, 2019-2021 ARM Limited. All rights reserved.
#
# This program is free software and is provided to you under the terms of the
# GNU General Public License version 2 as published by the Free Software
# Foundation, and any use by you of this program is subject to the terms
# of such GNU license.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, you can access it online at
# http://www.gnu.org/licenses/gpl-2.0.html.
#
#


* ARM Mali Midgard OPP

* OPP Table Node

This describes the OPPs belonging to a device. This node can have following
properties:

Required properties:
- compatible: Allow OPPs to express their compatibility. It should be:
  "operating-points-v2", "operating-points-v2-mali".

- OPP nodes: One or more OPP nodes describing voltage-current-frequency
  combinations. Their name isn't significant but their phandle can be used to
  reference an OPP.

* OPP Node

This defines voltage-current-frequency combinations along with other related
properties.

Required properties:
- opp-hz: Nominal frequency in Hz, expressed as a 64-bit big-endian integer.
  This should be treated as a relative performance measurement, taking both GPU
  frequency and core mask into account.

Optional properties:
- opp-hz-real: List of one or two real frequencies in Hz, expressed as 64-bit
  big-endian integers. They shall correspond to the clocks declared under
  the Mali device node, and follow the same order.

- opp-core-mask: Shader core mask. If neither this or opp-core-count are present
  then all shader cores will be used for this OPP.

- opp-core-count: Number of cores to use for this OPP. If this is present then
  the driver will build a core mask using the available core mask provided by
  the GPU hardware. An opp-core-count value of 0 is not permitted.

  If neither this nor opp-core-mask are present then all shader cores will be
  used for this OPP.

  If both this and opp-core-mask are present then opp-core-mask is ignored.

- opp-microvolt: List of one or two voltages in micro Volts. They shall correspond
  to the regulators declared under the Mali device node, and follow the order:
  "logic", "memory".

  A single regulator's voltage is specified with an array of size one or three.
  Single entry is for target voltage and three entries are for <target min max>
  voltages.

  Entries for multiple regulators must be present in the same order as
  regulators are specified in device's DT node.

- opp-microvolt-<name>: Named opp-microvolt property. This is exactly similar to
  the above opp-microvolt property, but allows multiple voltage ranges to be
  provided for the same OPP. At runtime, the platform can pick a <name> and
  matching opp-microvolt-<name> property will be enabled for all OPPs. If the
  platform doesn't pick a specific <name> or the <name> doesn't match with any
  opp-microvolt-<name> properties, then opp-microvolt property shall be used, if
  present.

- opp-microamp: The maximum current drawn by the device in microamperes
  considering system specific parameters (such as transients, process, aging,
  maximum operating temperature range etc.) as necessary. This may be used to
  set the most efficient regulator operating mode.

  Should only be set if opp-microvolt is set for the OPP.

  Entries for multiple regulators must be present in the same order as
  regulators are specified in device's DT node. If this property isn't required
  for few regulators, then this should be marked as zero for them. If it isn't
  required for any regulator, then this property need not be present.

- opp-microamp-<name>: Named opp-microamp property. Similar to
  opp-microvolt-<name> property, but for microamp instead.

- clock-latency-ns: Specifies the maximum possible transition latency (in
  nanoseconds) for switching to this OPP from any other OPP.

- turbo-mode: Marks the OPP to be used only for turbo modes. Turbo mode is
  available on some platforms, where the device can run over its operating
  frequency for a short duration of time limited by the device's power, current
  and thermal limits.

- opp-suspend: Marks the OPP to be used during device suspend. Only one OPP in
  the table should have this.

- opp-mali-errata-1485982: Marks the OPP to be selected for suspend clock.
  This will be effective only if MALI_HW_ERRATA_1485982_USE_CLOCK_ALTERNATIVE is
  enabled. It needs to be placed in any OPP that has proper suspend clock for
  the HW workaround.

- opp-supported-hw: This enables us to select only a subset of OPPs from the
  larger OPP table, based on what version of the hardware we are running on. We
  still can't have multiple nodes with the same opp-hz value in OPP table.

  It's an user defined array containing a hierarchy of hardware version numbers,
  supported by the OPP. For example: a platform with hierarchy of three levels
  of versions (A, B and C), this field should be like <X Y Z>, where X
  corresponds to Version hierarchy A, Y corresponds to version hierarchy B and Z
  corresponds to version hierarchy C.

  Each level of hierarchy is represented by a 32 bit value, and so there can be
  only 32 different supported version per hierarchy. i.e. 1 bit per version. A
  value of 0xFFFFFFFF will enable the OPP for all versions for that hierarchy
  level. And a value of 0x00000000 will disable the OPP completely, and so we
  never want that to happen.

  If 32 values aren't sufficient for a version hierarchy, than that version
  hierarchy can be contained in multiple 32 bit values. i.e. <X Y Z1 Z2> in the
  above example, Z1 & Z2 refer to the version hierarchy Z.

- status: Marks the node enabled/disabled.

Example for a Juno with 1 clock and 1 regulator:

gpu_opp_table: opp_table0 {
	compatible = "operating-points-v2", "operating-points-v2-mali";

	opp@112500000 {
		opp-hz = /bits/ 64 <112500000>;
		opp-hz-real = /bits/ 64 <450000000>;
		opp-microvolt = <820000>;
		opp-core-mask = /bits/ 64 <0x1>;
		opp-suspend;
		opp-mali-errata-1485982;
	};
	opp@225000000 {
		opp-hz = /bits/ 64 <225000000>;
		opp-hz-real = /bits/ 64 <450000000>;
		opp-microvolt = <820000>;
		opp-core-count = <2>;
	};
	opp@450000000 {
		opp-hz = /bits/ 64 <450000000>;
		opp-hz-real = /bits/ 64 <450000000>;
		opp-microvolt = <820000>;
		opp-core-mask = /bits/ 64 <0xf>;
	};
	opp@487500000 {
		opp-hz = /bits/ 64 <487500000>;
		opp-microvolt = <825000>;
	};
	opp@525000000 {
		opp-hz = /bits/ 64 <525000000>;
		opp-microvolt = <850000>;
	};
	opp@562500000 {
		opp-hz = /bits/ 64 <562500000>;
		opp-microvolt = <875000>;
	};
	opp@600000000 {
		opp-hz = /bits/ 64 <600000000>;
		opp-microvolt = <900000>;
	};
};

Example for a Juno with 2 clocks and 2 regulators:

gpu_opp_table: opp_table0 {
	compatible = "operating-points-v2", "operating-points-v2-mali";

	opp@0 {
		opp-hz = /bits/ 64 <50000000>;
		opp-hz-real = /bits/ 64 <50000000>, /bits/ 64 <45000000>;
		opp-microvolt = <820000>, <800000>;
		opp-core-mask = /bits/ 64 <0xf>;
	};
	opp@1 {
		opp-hz = /bits/ 64 <40000000>;
		opp-hz-real = /bits/ 64 <40000000>, /bits/ 64 <35000000>;
		opp-microvolt = <720000>, <700000>;
		opp-core-mask = /bits/ 64 <0x7>;
	};
	opp@2 {
		opp-hz = /bits/ 64 <30000000>;
		opp-hz-real = /bits/ 64 <30000000>, /bits/ 64 <25000000>;
		opp-microvolt = <620000>, <700000>;
		opp-core-mask = /bits/ 64 <0x3>;
	};
};