intel_dptf.rst (8613B)
1.. SPDX-License-Identifier: GPL-2.0 2 3=============================================================== 4Intel(R) Dynamic Platform and Thermal Framework Sysfs Interface 5=============================================================== 6 7:Copyright: © 2022 Intel Corporation 8 9:Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> 10 11Introduction 12------------ 13 14Intel(R) Dynamic Platform and Thermal Framework (DPTF) is a platform 15level hardware/software solution for power and thermal management. 16 17As a container for multiple power/thermal technologies, DPTF provides 18a coordinated approach for different policies to effect the hardware 19state of a system. 20 21Since it is a platform level framework, this has several components. 22Some parts of the technology is implemented in the firmware and uses 23ACPI and PCI devices to expose various features for monitoring and 24control. Linux has a set of kernel drivers exposing hardware interface 25to user space. This allows user space thermal solutions like 26"Linux Thermal Daemon" to read platform specific thermal and power 27tables to deliver adequate performance while keeping the system under 28thermal limits. 29 30DPTF ACPI Drivers interface 31---------------------------- 32 33:file:`/sys/bus/platform/devices/<N>/uuids`, where <N> 34=INT3400|INTC1040|INTC1041|INTC10A0 35 36``available_uuids`` (RO) 37 A set of UUIDs strings presenting available policies 38 which should be notified to the firmware when the 39 user space can support those policies. 40 41 UUID strings: 42 43 "42A441D6-AE6A-462b-A84B-4A8CE79027D3" : Passive 1 44 45 "3A95C389-E4B8-4629-A526-C52C88626BAE" : Active 46 47 "97C68AE7-15FA-499c-B8C9-5DA81D606E0A" : Critical 48 49 "63BE270F-1C11-48FD-A6F7-3AF253FF3E2D" : Adaptive performance 50 51 "5349962F-71E6-431D-9AE8-0A635B710AEE" : Emergency call 52 53 "9E04115A-AE87-4D1C-9500-0F3E340BFE75" : Passive 2 54 55 "F5A35014-C209-46A4-993A-EB56DE7530A1" : Power Boss 56 57 "6ED722A7-9240-48A5-B479-31EEF723D7CF" : Virtual Sensor 58 59 "16CAF1B7-DD38-40ED-B1C1-1B8A1913D531" : Cooling mode 60 61 "BE84BABF-C4D4-403D-B495-3128FD44dAC1" : HDC 62 63``current_uuid`` (RW) 64 User space can write strings from available UUIDs, one at a 65 time. 66 67:file:`/sys/bus/platform/devices/<N>/`, where <N> 68=INT3400|INTC1040|INTC1041|INTC10A0 69 70``imok`` (WO) 71 User space daemon write 1 to respond to firmware event 72 for sending keep alive notification. User space receives 73 THERMAL_EVENT_KEEP_ALIVE kobject uevent notification when 74 firmware calls for user space to respond with imok ACPI 75 method. 76 77``odvp*`` (RO) 78 Firmware thermal status variable values. Thermal tables 79 calls for different processing based on these variable 80 values. 81 82``data_vault`` (RO) 83 Binary thermal table. Refer to 84 https:/github.com/intel/thermal_daemon for decoding 85 thermal table. 86 87 88ACPI Thermal Relationship table interface 89------------------------------------------ 90 91:file:`/dev/acpi_thermal_rel` 92 93 This device provides IOCTL interface to read standard ACPI 94 thermal relationship tables via ACPI methods _TRT and _ART. 95 These IOCTLs are defined in 96 drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h 97 98 IOCTLs: 99 100 ACPI_THERMAL_GET_TRT_LEN: Get length of TRT table 101 102 ACPI_THERMAL_GET_ART_LEN: Get length of ART table 103 104 ACPI_THERMAL_GET_TRT_COUNT: Number of records in TRT table 105 106 ACPI_THERMAL_GET_ART_COUNT: Number of records in ART table 107 108 ACPI_THERMAL_GET_TRT: Read binary TRT table, length to read is 109 provided via argument to ioctl(). 110 111 ACPI_THERMAL_GET_ART: Read binary ART table, length to read is 112 provided via argument to ioctl(). 113 114DPTF ACPI Sensor drivers 115------------------------- 116 117DPTF Sensor drivers are presented as standard thermal sysfs thermal_zone. 118 119 120DPTF ACPI Cooling drivers 121-------------------------- 122 123DPTF cooling drivers are presented as standard thermal sysfs cooling_device. 124 125 126DPTF Processor thermal PCI Driver interface 127-------------------------------------------- 128 129:file:`/sys/bus/pci/devices/0000\:00\:04.0/power_limits/` 130 131Refer to Documentation/power/powercap/powercap.rst for powercap 132ABI. 133 134``power_limit_0_max_uw`` (RO) 135 Maximum powercap sysfs constraint_0_power_limit_uw for Intel RAPL 136 137``power_limit_0_step_uw`` (RO) 138 Power limit increment/decrements for Intel RAPL constraint 0 power limit 139 140``power_limit_0_min_uw`` (RO) 141 Minimum powercap sysfs constraint_0_power_limit_uw for Intel RAPL 142 143``power_limit_0_tmin_us`` (RO) 144 Minimum powercap sysfs constraint_0_time_window_us for Intel RAPL 145 146``power_limit_0_tmax_us`` (RO) 147 Maximum powercap sysfs constraint_0_time_window_us for Intel RAPL 148 149``power_limit_1_max_uw`` (RO) 150 Maximum powercap sysfs constraint_1_power_limit_uw for Intel RAPL 151 152``power_limit_1_step_uw`` (RO) 153 Power limit increment/decrements for Intel RAPL constraint 1 power limit 154 155``power_limit_1_min_uw`` (RO) 156 Minimum powercap sysfs constraint_1_power_limit_uw for Intel RAPL 157 158``power_limit_1_tmin_us`` (RO) 159 Minimum powercap sysfs constraint_1_time_window_us for Intel RAPL 160 161``power_limit_1_tmax_us`` (RO) 162 Maximum powercap sysfs constraint_1_time_window_us for Intel RAPL 163 164:file:`/sys/bus/pci/devices/0000\:00\:04.0/` 165 166``tcc_offset_degree_celsius`` (RW) 167 TCC offset from the critical temperature where hardware will throttle 168 CPU. 169 170:file:`/sys/bus/pci/devices/0000\:00\:04.0/workload_request` 171 172``workload_available_types`` (RO) 173 Available workload types. User space can specify one of the workload type 174 it is currently executing via workload_type. For example: idle, bursty, 175 sustained etc. 176 177``workload_type`` (RW) 178 User space can specify any one of the available workload type using 179 this interface. 180 181DPTF Processor thermal RFIM interface 182-------------------------------------------- 183 184RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator) 185and DDR (Double Data Rate)frequencies to avoid RF interference with WiFi and 5G. 186 187Switching voltage regulators (VR) generate radiated EMI or RFI at the 188fundamental frequency and its harmonics. Some harmonics may interfere 189with very sensitive wireless receivers such as Wi-Fi and cellular that 190are integrated into host systems like notebook PCs. One of mitigation 191methods is requesting SOC integrated VR (IVR) switching frequency to a 192small % and shift away the switching noise harmonic interference from 193radio channels. OEM or ODMs can use the driver to control SOC IVR 194operation within the range where it does not impact IVR performance. 195 196DRAM devices of DDR IO interface and their power plane can generate EMI 197at the data rates. Similar to IVR control mechanism, Intel offers a 198mechanism by which DDR data rates can be changed if several conditions 199are met: there is strong RFI interference because of DDR; CPU power 200management has no other restriction in changing DDR data rates; 201PC ODMs enable this feature (real time DDR RFI Mitigation referred to as 202DDR-RFIM) for Wi-Fi from BIOS. 203 204 205FIVR attributes 206 207:file:`/sys/bus/pci/devices/0000\:00\:04.0/fivr/` 208 209``vco_ref_code_lo`` (RW) 210 The VCO reference code is an 11-bit field and controls the FIVR 211 switching frequency. This is the 3-bit LSB field. 212 213``vco_ref_code_hi`` (RW) 214 The VCO reference code is an 11-bit field and controls the FIVR 215 switching frequency. This is the 8-bit MSB field. 216 217``spread_spectrum_pct`` (RW) 218 Set the FIVR spread spectrum clocking percentage 219 220``spread_spectrum_clk_enable`` (RW) 221 Enable/disable of the FIVR spread spectrum clocking feature 222 223``rfi_vco_ref_code`` (RW) 224 This field is a read only status register which reflects the 225 current FIVR switching frequency 226 227``fivr_fffc_rev`` (RW) 228 This field indicated the revision of the FIVR HW. 229 230 231DVFS attributes 232 233:file:`/sys/bus/pci/devices/0000\:00\:04.0/dvfs/` 234 235``rfi_restriction_run_busy`` (RW) 236 Request the restriction of specific DDR data rate and set this 237 value 1. Self reset to 0 after operation. 238 239``rfi_restriction_err_code`` (RW) 240 0 :Request is accepted, 1:Feature disabled, 241 2: the request restricts more points than it is allowed 242 243``rfi_restriction_data_rate_Delta`` (RW) 244 Restricted DDR data rate for RFI protection: Lower Limit 245 246``rfi_restriction_data_rate_Base`` (RW) 247 Restricted DDR data rate for RFI protection: Upper Limit 248 249``ddr_data_rate_point_0`` (RO) 250 DDR data rate selection 1st point 251 252``ddr_data_rate_point_1`` (RO) 253 DDR data rate selection 2nd point 254 255``ddr_data_rate_point_2`` (RO) 256 DDR data rate selection 3rd point 257 258``ddr_data_rate_point_3`` (RO) 259 DDR data rate selection 4th point 260 261``rfi_disable (RW)`` 262 Disable DDR rate change feature 263 264DPTF Power supply and Battery Interface 265---------------------------------------- 266 267Refer to Documentation/ABI/testing/sysfs-platform-dptf 268 269DPTF Fan Control 270---------------------------------------- 271 272Refer to Documentation/admin-guide/acpi/fan_performance_states.rst