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diff --git a/Documentation/driver-api/thermal/intel_dptf.rst b/Documentation/driver-api/thermal/intel_dptf.rst new file mode 100644 index 000000000..372bdb4d0 --- /dev/null +++ b/Documentation/driver-api/thermal/intel_dptf.rst @@ -0,0 +1,272 @@ +.. 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. + + +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) +and DDR (Double Data Rate)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. + +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 + +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 |