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``production_mode`` (RO) 88 When different from zero, manufacturer locked thermal configuration 89 from further changes. 90 91ACPI Thermal Relationship table interface 92------------------------------------------ 93 94:file:`/dev/acpi_thermal_rel` 95 96 This device provides IOCTL interface to read standard ACPI 97 thermal relationship tables via ACPI methods _TRT and _ART. 98 These IOCTLs are defined in 99 drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.h 100 101 IOCTLs: 102 103 ACPI_THERMAL_GET_TRT_LEN: Get length of TRT table 104 105 ACPI_THERMAL_GET_ART_LEN: Get length of ART table 106 107 ACPI_THERMAL_GET_TRT_COUNT: Number of records in TRT table 108 109 ACPI_THERMAL_GET_ART_COUNT: Number of records in ART table 110 111 ACPI_THERMAL_GET_TRT: Read binary TRT table, length to read is 112 provided via argument to ioctl(). 113 114 ACPI_THERMAL_GET_ART: Read binary ART table, length to read is 115 provided via argument to ioctl(). 116 117DPTF ACPI Sensor drivers 118------------------------- 119 120DPTF Sensor drivers are presented as standard thermal sysfs thermal_zone. 121 122 123DPTF ACPI Cooling drivers 124-------------------------- 125 126DPTF cooling drivers are presented as standard thermal sysfs cooling_device. 127 128 129DPTF Processor thermal PCI Driver interface 130-------------------------------------------- 131 132:file:`/sys/bus/pci/devices/0000\:00\:04.0/power_limits/` 133 134Refer to Documentation/power/powercap/powercap.rst for powercap 135ABI. 136 137``power_limit_0_max_uw`` (RO) 138 Maximum powercap sysfs constraint_0_power_limit_uw for Intel RAPL 139 140``power_limit_0_step_uw`` (RO) 141 Power limit increment/decrements for Intel RAPL constraint 0 power limit 142 143``power_limit_0_min_uw`` (RO) 144 Minimum powercap sysfs constraint_0_power_limit_uw for Intel RAPL 145 146``power_limit_0_tmin_us`` (RO) 147 Minimum powercap sysfs constraint_0_time_window_us for Intel RAPL 148 149``power_limit_0_tmax_us`` (RO) 150 Maximum powercap sysfs constraint_0_time_window_us for Intel RAPL 151 152``power_limit_1_max_uw`` (RO) 153 Maximum powercap sysfs constraint_1_power_limit_uw for Intel RAPL 154 155``power_limit_1_step_uw`` (RO) 156 Power limit increment/decrements for Intel RAPL constraint 1 power limit 157 158``power_limit_1_min_uw`` (RO) 159 Minimum powercap sysfs constraint_1_power_limit_uw for Intel RAPL 160 161``power_limit_1_tmin_us`` (RO) 162 Minimum powercap sysfs constraint_1_time_window_us for Intel RAPL 163 164``power_limit_1_tmax_us`` (RO) 165 Maximum powercap sysfs constraint_1_time_window_us for Intel RAPL 166 167:file:`/sys/bus/pci/devices/0000\:00\:04.0/` 168 169``tcc_offset_degree_celsius`` (RW) 170 TCC offset from the critical temperature where hardware will throttle 171 CPU. 172 173:file:`/sys/bus/pci/devices/0000\:00\:04.0/workload_request` 174 175``workload_available_types`` (RO) 176 Available workload types. User space can specify one of the workload type 177 it is currently executing via workload_type. For example: idle, bursty, 178 sustained etc. 179 180``workload_type`` (RW) 181 User space can specify any one of the available workload type using 182 this interface. 183 184DPTF Processor thermal RFIM interface 185-------------------------------------------- 186 187RFIM interface allows adjustment of FIVR (Fully Integrated Voltage Regulator) 188and DDR (Double Data Rate)frequencies to avoid RF interference with WiFi and 5G. 189 190Switching voltage regulators (VR) generate radiated EMI or RFI at the 191fundamental frequency and its harmonics. Some harmonics may interfere 192with very sensitive wireless receivers such as Wi-Fi and cellular that 193are integrated into host systems like notebook PCs. One of mitigation 194methods is requesting SOC integrated VR (IVR) switching frequency to a 195small % and shift away the switching noise harmonic interference from 196radio channels. OEM or ODMs can use the driver to control SOC IVR 197operation within the range where it does not impact IVR performance. 198 199DRAM devices of DDR IO interface and their power plane can generate EMI 200at the data rates. Similar to IVR control mechanism, Intel offers a 201mechanism by which DDR data rates can be changed if several conditions 202are met: there is strong RFI interference because of DDR; CPU power 203management has no other restriction in changing DDR data rates; 204PC ODMs enable this feature (real time DDR RFI Mitigation referred to as 205DDR-RFIM) for Wi-Fi from BIOS. 206 207 208FIVR attributes 209 210:file:`/sys/bus/pci/devices/0000\:00\:04.0/fivr/` 211 212``vco_ref_code_lo`` (RW) 213 The VCO reference code is an 11-bit field and controls the FIVR 214 switching frequency. This is the 3-bit LSB field. 215 216``vco_ref_code_hi`` (RW) 217 The VCO reference code is an 11-bit field and controls the FIVR 218 switching frequency. This is the 8-bit MSB field. 219 220``spread_spectrum_pct`` (RW) 221 Set the FIVR spread spectrum clocking percentage 222 223``spread_spectrum_clk_enable`` (RW) 224 Enable/disable of the FIVR spread spectrum clocking feature 225 226``rfi_vco_ref_code`` (RW) 227 This field is a read only status register which reflects the 228 current FIVR switching frequency 229 230``fivr_fffc_rev`` (RW) 231 This field indicated the revision of the FIVR HW. 232 233 234DVFS attributes 235 236:file:`/sys/bus/pci/devices/0000\:00\:04.0/dvfs/` 237 238``rfi_restriction_run_busy`` (RW) 239 Request the restriction of specific DDR data rate and set this 240 value 1. Self reset to 0 after operation. 241 242``rfi_restriction_err_code`` (RW) 243 0 :Request is accepted, 1:Feature disabled, 244 2: the request restricts more points than it is allowed 245 246``rfi_restriction_data_rate_Delta`` (RW) 247 Restricted DDR data rate for RFI protection: Lower Limit 248 249``rfi_restriction_data_rate_Base`` (RW) 250 Restricted DDR data rate for RFI protection: Upper Limit 251 252``ddr_data_rate_point_0`` (RO) 253 DDR data rate selection 1st point 254 255``ddr_data_rate_point_1`` (RO) 256 DDR data rate selection 2nd point 257 258``ddr_data_rate_point_2`` (RO) 259 DDR data rate selection 3rd point 260 261``ddr_data_rate_point_3`` (RO) 262 DDR data rate selection 4th point 263 264``rfi_disable (RW)`` 265 Disable DDR rate change feature 266 267DPTF Power supply and Battery Interface 268---------------------------------------- 269 270Refer to Documentation/ABI/testing/sysfs-platform-dptf 271 272DPTF Fan Control 273---------------------------------------- 274 275Refer to Documentation/admin-guide/acpi/fan_performance_states.rst 276