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	Documentation: thermal: DPTF Documentation
Document Intel Dynamic Platform and Thermal Framework (DPTF) ABI. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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			@ -17,3 +17,4 @@ Thermal
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   intel_powerclamp
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   nouveau_thermal
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   x86_pkg_temperature_thermal
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   intel_dptf
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								Documentation/driver-api/thermal/intel_dptf.rst
									
									
									
									
									
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								Documentation/driver-api/thermal/intel_dptf.rst
									
									
									
									
									
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.. SPDX-License-Identifier: GPL-2.0
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===============================================================
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Intel(R) Dynamic Platform and Thermal Framework Sysfs Interface
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===============================================================
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:Copyright: |copy| 2022 Intel Corporation
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:Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
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Introduction
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------------
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Intel(R) Dynamic Platform and Thermal Framework (DPTF) is a platform
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level hardware/software solution for power and thermal management.
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As a container for multiple power/thermal technologies, DPTF provides
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a coordinated approach for different policies to effect the hardware
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state of a system.
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Since it is a platform level framework, this has several components.
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Some parts of the technology is implemented in the firmware and uses
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ACPI and PCI devices to expose various features for monitoring and
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control. Linux has a set of kernel drivers exposing hardware interface
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to user space. This allows user space thermal solutions like
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"Linux Thermal Daemon" to read platform specific thermal and power
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tables to deliver adequate performance while keeping the system under
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thermal limits.
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DPTF ACPI Drivers interface
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----------------------------
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:file:`/sys/bus/platform/devices/<N>/uuids`, where <N>
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=INT3400|INTC1040|INTC1041|INTC10A0
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``available_uuids`` (RO)
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	A set of UUIDs strings presenting available policies
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	which should be notified to the firmware when the
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	user space can support those policies.
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	UUID strings:
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	"42A441D6-AE6A-462b-A84B-4A8CE79027D3" : Passive 1
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	"3A95C389-E4B8-4629-A526-C52C88626BAE" : Active
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	"97C68AE7-15FA-499c-B8C9-5DA81D606E0A" : Critical
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	"63BE270F-1C11-48FD-A6F7-3AF253FF3E2D" : Adaptive performance
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	"5349962F-71E6-431D-9AE8-0A635B710AEE" : Emergency call
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	"9E04115A-AE87-4D1C-9500-0F3E340BFE75" : Passive 2
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	"F5A35014-C209-46A4-993A-EB56DE7530A1" : Power Boss
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	"6ED722A7-9240-48A5-B479-31EEF723D7CF" : Virtual Sensor
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	"16CAF1B7-DD38-40ED-B1C1-1B8A1913D531" : Cooling mode
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	"BE84BABF-C4D4-403D-B495-3128FD44dAC1" : HDC
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``current_uuid`` (RW)
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	User space can write strings from available UUIDs, one at a
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	time.
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:file:`/sys/bus/platform/devices/<N>/`, where <N>
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=INT3400|INTC1040|INTC1041|INTC10A0
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``imok`` (WO)
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	User space daemon write 1 to respond to firmware event
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	for sending keep alive notification. User space receives
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	THERMAL_EVENT_KEEP_ALIVE kobject uevent notification when
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	firmware calls for user space to respond with imok ACPI
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	method.
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``odvp*`` (RO)
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	Firmware thermal status variable values. Thermal tables
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	calls for different processing based on these variable
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	values.
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``data_vault`` (RO)
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	Binary thermal table. Refer to
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	https:/github.com/intel/thermal_daemon for decoding
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	thermal table.
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ACPI Thermal Relationship table interface
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------------------------------------------
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:file:`/dev/acpi_thermal_rel`
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	This device provides IOCTL interface to read standard ACPI
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	thermal relationship tables via ACPI methods _TRT and _ART.
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	These IOCTLs are defined in
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	drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
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	IOCTLs:
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	ACPI_THERMAL_GET_TRT_LEN: Get length of TRT table
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	ACPI_THERMAL_GET_ART_LEN: Get length of ART table
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	ACPI_THERMAL_GET_TRT_COUNT: Number of records in TRT table
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	ACPI_THERMAL_GET_ART_COUNT: Number of records in ART table
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	ACPI_THERMAL_GET_TRT: Read binary TRT table, length to read is
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	provided via argument to ioctl().
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	ACPI_THERMAL_GET_ART: Read binary ART table, length to read is
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	provided via argument to ioctl().
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DPTF ACPI Sensor drivers
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-------------------------
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DPTF Sensor drivers are presented as standard thermal sysfs thermal_zone.
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DPTF ACPI Cooling drivers
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--------------------------
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DPTF cooling drivers are presented as standard thermal sysfs cooling_device.
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DPTF Processor thermal PCI Driver interface
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--------------------------------------------
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:file:`/sys/bus/pci/devices/0000\:00\:04.0/power_limits/`
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Refer to Documentation/power/powercap/powercap.rst for powercap
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ABI.
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``power_limit_0_max_uw`` (RO)
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	Maximum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
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``power_limit_0_step_uw`` (RO)
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	Power limit increment/decrements for Intel RAPL constraint 0 power limit
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``power_limit_0_min_uw`` (RO)
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	Minimum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
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``power_limit_0_tmin_us`` (RO)
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	Minimum powercap sysfs constraint_0_time_window_us for Intel RAPL
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``power_limit_0_tmax_us`` (RO)
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	Maximum powercap sysfs constraint_0_time_window_us for Intel RAPL
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``power_limit_1_max_uw`` (RO)
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	Maximum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
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``power_limit_1_step_uw`` (RO)
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	Power limit increment/decrements for Intel RAPL constraint 1 power limit
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``power_limit_1_min_uw`` (RO)
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	Minimum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
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``power_limit_1_tmin_us`` (RO)
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	Minimum powercap sysfs constraint_1_time_window_us for Intel RAPL
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``power_limit_1_tmax_us`` (RO)
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	Maximum powercap sysfs constraint_1_time_window_us for Intel RAPL
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:file:`/sys/bus/pci/devices/0000\:00\:04.0/`
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``tcc_offset_degree_celsius`` (RW)
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	TCC offset from the critical temperature where hardware will throttle
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	CPU.
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:file:`/sys/bus/pci/devices/0000\:00\:04.0/workload_request`
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``workload_available_types`` (RO)
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	Available workload types. User space can specify one of the workload type
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	it is currently executing via workload_type. For example: idle, bursty,
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	sustained etc.
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``workload_type`` (RW)
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	User space can specify any one of the available workload type using
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	this interface.
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DPTF Processor thermal RFIM interface
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--------------------------------------------
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RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator)
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and DDR (Double Data Rate)frequencies to avoid RF interference with WiFi and 5G.
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Switching voltage regulators (VR) generate radiated EMI or RFI at the
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fundamental frequency and its harmonics. Some harmonics may interfere
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with very sensitive wireless receivers such as Wi-Fi and cellular that
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are integrated into host systems like notebook PCs.  One of mitigation
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methods is requesting SOC integrated VR (IVR) switching frequency to a
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small % and shift away the switching noise harmonic interference from
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radio channels.  OEM or ODMs can use the driver to control SOC IVR
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operation within the range where it does not impact IVR performance.
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DRAM devices of DDR IO interface and their power plane can generate EMI
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at the data rates. Similar to IVR control mechanism, Intel offers a
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mechanism by which DDR data rates can be changed if several conditions
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are met: there is strong RFI interference because of DDR; CPU power
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management has no other restriction in changing DDR data rates;
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PC ODMs enable this feature (real time DDR RFI Mitigation referred to as
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DDR-RFIM) for Wi-Fi from BIOS.
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FIVR attributes
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:file:`/sys/bus/pci/devices/0000\:00\:04.0/fivr/`
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``vco_ref_code_lo`` (RW)
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	The VCO reference code is an 11-bit field and controls the FIVR
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	switching frequency. This is the 3-bit LSB field.
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``vco_ref_code_hi`` (RW)
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	The VCO reference code is an 11-bit field and controls the FIVR
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	switching frequency. This is the 8-bit MSB field.
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``spread_spectrum_pct`` (RW)
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	Set the FIVR spread spectrum clocking percentage
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``spread_spectrum_clk_enable`` (RW)
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	Enable/disable of the FIVR spread spectrum clocking feature
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``rfi_vco_ref_code`` (RW)
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	This field is a read only status register which reflects the
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	current FIVR switching frequency
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``fivr_fffc_rev`` (RW)
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	This field indicated the revision of the FIVR HW.
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DVFS attributes
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:file:`/sys/bus/pci/devices/0000\:00\:04.0/dvfs/`
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``rfi_restriction_run_busy`` (RW)
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	Request the restriction of specific DDR data rate and set this
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	value 1. Self reset to 0 after operation.
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``rfi_restriction_err_code`` (RW)
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	0 :Request is accepted, 1:Feature disabled,
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	2: the request restricts more points than it is allowed
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``rfi_restriction_data_rate_Delta`` (RW)
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	Restricted DDR data rate for RFI protection: Lower Limit
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``rfi_restriction_data_rate_Base`` (RW)
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	Restricted DDR data rate for RFI protection: Upper Limit
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``ddr_data_rate_point_0`` (RO)
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	DDR data rate selection 1st point
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``ddr_data_rate_point_1`` (RO)
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	DDR data rate selection 2nd point
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``ddr_data_rate_point_2`` (RO)
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	DDR data rate selection 3rd point
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``ddr_data_rate_point_3`` (RO)
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	DDR data rate selection 4th point
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``rfi_disable (RW)``
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	Disable DDR rate change feature
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DPTF Power supply and Battery Interface
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----------------------------------------
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Refer to Documentation/ABI/testing/sysfs-platform-dptf
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DPTF Fan Control
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----------------------------------------
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Refer to Documentation/admin-guide/acpi/fan_performance_states.rst
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