0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 ===============================================================
0004 Intel(R) Dynamic Platform and Thermal Framework Sysfs Interface
0005 ===============================================================
0006
0007 :Copyright: © 2022 Intel Corporation
0008
0009 :Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
0010
0011 Introduction
0012 ------------
0013
0014 Intel(R) Dynamic Platform and Thermal Framework (DPTF) is a platform
0015 level hardware/software solution for power and thermal management.
0016
0017 As a container for multiple power/thermal technologies, DPTF provides
0018 a coordinated approach for different policies to effect the hardware
0019 state of a system.
0020
0021 Since it is a platform level framework, this has several components.
0022 Some parts of the technology is implemented in the firmware and uses
0023 ACPI and PCI devices to expose various features for monitoring and
0024 control. Linux has a set of kernel drivers exposing hardware interface
0025 to user space. This allows user space thermal solutions like
0026 "Linux Thermal Daemon" to read platform specific thermal and power
0027 tables to deliver adequate performance while keeping the system under
0028 thermal limits.
0029
0030 DPTF ACPI Drivers interface
0031 ----------------------------
0032
0033 :file:`/sys/bus/platform/devices/<N>/uuids`, where <N>
0034 =INT3400|INTC1040|INTC1041|INTC10A0
0035
0036 ``available_uuids`` (RO)
0037 A set of UUIDs strings presenting available policies
0038 which should be notified to the firmware when the
0039 user space can support those policies.
0040
0041 UUID strings:
0042
0043 "42A441D6-AE6A-462b-A84B-4A8CE79027D3" : Passive 1
0044
0045 "3A95C389-E4B8-4629-A526-C52C88626BAE" : Active
0046
0047 "97C68AE7-15FA-499c-B8C9-5DA81D606E0A" : Critical
0048
0049 "63BE270F-1C11-48FD-A6F7-3AF253FF3E2D" : Adaptive performance
0050
0051 "5349962F-71E6-431D-9AE8-0A635B710AEE" : Emergency call
0052
0053 "9E04115A-AE87-4D1C-9500-0F3E340BFE75" : Passive 2
0054
0055 "F5A35014-C209-46A4-993A-EB56DE7530A1" : Power Boss
0056
0057 "6ED722A7-9240-48A5-B479-31EEF723D7CF" : Virtual Sensor
0058
0059 "16CAF1B7-DD38-40ED-B1C1-1B8A1913D531" : Cooling mode
0060
0061 "BE84BABF-C4D4-403D-B495-3128FD44dAC1" : HDC
0062
0063 ``current_uuid`` (RW)
0064 User space can write strings from available UUIDs, one at a
0065 time.
0066
0067 :file:`/sys/bus/platform/devices/<N>/`, where <N>
0068 =INT3400|INTC1040|INTC1041|INTC10A0
0069
0070 ``imok`` (WO)
0071 User space daemon write 1 to respond to firmware event
0072 for sending keep alive notification. User space receives
0073 THERMAL_EVENT_KEEP_ALIVE kobject uevent notification when
0074 firmware calls for user space to respond with imok ACPI
0075 method.
0076
0077 ``odvp*`` (RO)
0078 Firmware thermal status variable values. Thermal tables
0079 calls for different processing based on these variable
0080 values.
0081
0082 ``data_vault`` (RO)
0083 Binary thermal table. Refer to
0084 https:/github.com/intel/thermal_daemon for decoding
0085 thermal table.
0086
0087
0088 ACPI Thermal Relationship table interface
0089 ------------------------------------------
0090
0091 :file:`/dev/acpi_thermal_rel`
0092
0093 This device provides IOCTL interface to read standard ACPI
0094 thermal relationship tables via ACPI methods _TRT and _ART.
0095 These IOCTLs are defined in
0096 drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h
0097
0098 IOCTLs:
0099
0100 ACPI_THERMAL_GET_TRT_LEN: Get length of TRT table
0101
0102 ACPI_THERMAL_GET_ART_LEN: Get length of ART table
0103
0104 ACPI_THERMAL_GET_TRT_COUNT: Number of records in TRT table
0105
0106 ACPI_THERMAL_GET_ART_COUNT: Number of records in ART table
0107
0108 ACPI_THERMAL_GET_TRT: Read binary TRT table, length to read is
0109 provided via argument to ioctl().
0110
0111 ACPI_THERMAL_GET_ART: Read binary ART table, length to read is
0112 provided via argument to ioctl().
0113
0114 DPTF ACPI Sensor drivers
0115 -------------------------
0116
0117 DPTF Sensor drivers are presented as standard thermal sysfs thermal_zone.
0118
0119
0120 DPTF ACPI Cooling drivers
0121 --------------------------
0122
0123 DPTF cooling drivers are presented as standard thermal sysfs cooling_device.
0124
0125
0126 DPTF Processor thermal PCI Driver interface
0127 --------------------------------------------
0128
0129 :file:`/sys/bus/pci/devices/0000\:00\:04.0/power_limits/`
0130
0131 Refer to Documentation/power/powercap/powercap.rst for powercap
0132 ABI.
0133
0134 ``power_limit_0_max_uw`` (RO)
0135 Maximum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
0136
0137 ``power_limit_0_step_uw`` (RO)
0138 Power limit increment/decrements for Intel RAPL constraint 0 power limit
0139
0140 ``power_limit_0_min_uw`` (RO)
0141 Minimum powercap sysfs constraint_0_power_limit_uw for Intel RAPL
0142
0143 ``power_limit_0_tmin_us`` (RO)
0144 Minimum powercap sysfs constraint_0_time_window_us for Intel RAPL
0145
0146 ``power_limit_0_tmax_us`` (RO)
0147 Maximum powercap sysfs constraint_0_time_window_us for Intel RAPL
0148
0149 ``power_limit_1_max_uw`` (RO)
0150 Maximum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
0151
0152 ``power_limit_1_step_uw`` (RO)
0153 Power limit increment/decrements for Intel RAPL constraint 1 power limit
0154
0155 ``power_limit_1_min_uw`` (RO)
0156 Minimum powercap sysfs constraint_1_power_limit_uw for Intel RAPL
0157
0158 ``power_limit_1_tmin_us`` (RO)
0159 Minimum powercap sysfs constraint_1_time_window_us for Intel RAPL
0160
0161 ``power_limit_1_tmax_us`` (RO)
0162 Maximum powercap sysfs constraint_1_time_window_us for Intel RAPL
0163
0164 :file:`/sys/bus/pci/devices/0000\:00\:04.0/`
0165
0166 ``tcc_offset_degree_celsius`` (RW)
0167 TCC offset from the critical temperature where hardware will throttle
0168 CPU.
0169
0170 :file:`/sys/bus/pci/devices/0000\:00\:04.0/workload_request`
0171
0172 ``workload_available_types`` (RO)
0173 Available workload types. User space can specify one of the workload type
0174 it is currently executing via workload_type. For example: idle, bursty,
0175 sustained etc.
0176
0177 ``workload_type`` (RW)
0178 User space can specify any one of the available workload type using
0179 this interface.
0180
0181 DPTF Processor thermal RFIM interface
0182 --------------------------------------------
0183
0184 RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator)
0185 and DDR (Double Data Rate)frequencies to avoid RF interference with WiFi and 5G.
0186
0187 Switching voltage regulators (VR) generate radiated EMI or RFI at the
0188 fundamental frequency and its harmonics. Some harmonics may interfere
0189 with very sensitive wireless receivers such as Wi-Fi and cellular that
0190 are integrated into host systems like notebook PCs. One of mitigation
0191 methods is requesting SOC integrated VR (IVR) switching frequency to a
0192 small % and shift away the switching noise harmonic interference from
0193 radio channels. OEM or ODMs can use the driver to control SOC IVR
0194 operation within the range where it does not impact IVR performance.
0195
0196 DRAM devices of DDR IO interface and their power plane can generate EMI
0197 at the data rates. Similar to IVR control mechanism, Intel offers a
0198 mechanism by which DDR data rates can be changed if several conditions
0199 are met: there is strong RFI interference because of DDR; CPU power
0200 management has no other restriction in changing DDR data rates;
0201 PC ODMs enable this feature (real time DDR RFI Mitigation referred to as
0202 DDR-RFIM) for Wi-Fi from BIOS.
0203
0204
0205 FIVR attributes
0206
0207 :file:`/sys/bus/pci/devices/0000\:00\:04.0/fivr/`
0208
0209 ``vco_ref_code_lo`` (RW)
0210 The VCO reference code is an 11-bit field and controls the FIVR
0211 switching frequency. This is the 3-bit LSB field.
0212
0213 ``vco_ref_code_hi`` (RW)
0214 The VCO reference code is an 11-bit field and controls the FIVR
0215 switching frequency. This is the 8-bit MSB field.
0216
0217 ``spread_spectrum_pct`` (RW)
0218 Set the FIVR spread spectrum clocking percentage
0219
0220 ``spread_spectrum_clk_enable`` (RW)
0221 Enable/disable of the FIVR spread spectrum clocking feature
0222
0223 ``rfi_vco_ref_code`` (RW)
0224 This field is a read only status register which reflects the
0225 current FIVR switching frequency
0226
0227 ``fivr_fffc_rev`` (RW)
0228 This field indicated the revision of the FIVR HW.
0229
0230
0231 DVFS attributes
0232
0233 :file:`/sys/bus/pci/devices/0000\:00\:04.0/dvfs/`
0234
0235 ``rfi_restriction_run_busy`` (RW)
0236 Request the restriction of specific DDR data rate and set this
0237 value 1. Self reset to 0 after operation.
0238
0239 ``rfi_restriction_err_code`` (RW)
0240 0 :Request is accepted, 1:Feature disabled,
0241 2: the request restricts more points than it is allowed
0242
0243 ``rfi_restriction_data_rate_Delta`` (RW)
0244 Restricted DDR data rate for RFI protection: Lower Limit
0245
0246 ``rfi_restriction_data_rate_Base`` (RW)
0247 Restricted DDR data rate for RFI protection: Upper Limit
0248
0249 ``ddr_data_rate_point_0`` (RO)
0250 DDR data rate selection 1st point
0251
0252 ``ddr_data_rate_point_1`` (RO)
0253 DDR data rate selection 2nd point
0254
0255 ``ddr_data_rate_point_2`` (RO)
0256 DDR data rate selection 3rd point
0257
0258 ``ddr_data_rate_point_3`` (RO)
0259 DDR data rate selection 4th point
0260
0261 ``rfi_disable (RW)``
0262 Disable DDR rate change feature
0263
0264 DPTF Power supply and Battery Interface
0265 ----------------------------------------
0266
0267 Refer to Documentation/ABI/testing/sysfs-platform-dptf
0268
0269 DPTF Fan Control
0270 ----------------------------------------
0271
0272 Refer to Documentation/admin-guide/acpi/fan_performance_states.rst
