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