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| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2021-07-27 09:22:40 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-08-04 18:08:50 +0200 |
| commit | 7a6226db072beeb63d4c3aaa844b0676ef7a027f (patch) | |
| tree | 0ff7f4eb94291a6f491186a3f4683ec6898debe4 /Documentation/ABI | |
| parent | c500bee1c5b2f1d59b1081ac879d73268ab0ff17 (diff) | |
| download | linux-7a6226db072beeb63d4c3aaa844b0676ef7a027f.tar.gz | |
ACPI: DPTF: Add new PCH FIVR methods
Some additional information is required for updating PCH FIVR values upon WiFi channel changes. New attributes added to the existing sysfs: fivr_switching_freq_mhz : Get the FIVR switching control frequency. Uses ACPI method GFCS. fivr_switching_fault_status: Read the FIVR switching frequency control fault status. Uses ACPI method GFFS. ssc_clock_info : Presents SSC (spread spectrum clock) information for EMI (Electro magnetic interference) control. Use ACPI method GEMI (refer to the description of GEMI method below). GFFS This ACPI method is used to read the FIVR switching frequency control fault status. Bits Description [0:0] Fault status when set to 1 [31:1] Reserved GFCS This ACPI method is used to read the FIVR switching control frequency. Bits Description [11:0] Actual Frequency = value * XTAL_FREQ / 128 [31:12] Reserved GEMI This ACPI method is used to read the programmed register value for EMI (Electro magnetic interference) control. Bits Description [7:0] Sets clock spectrum spread percentage: 0x00=0.2% , 0x3F=10% 1 LSB = 0.1% increase in spread (for settings 0x01 thru 0x1C) 1 LSB = 0.2% increase in spread (for settings 0x1E thru 0x3F) [8] When set to 1, enables spread spectrum clock [9] 0: Triangle mode. FFC frequency walks around the Fcenter in a linear fashion 1: Random walk mode. FFC frequency changes randomly within the SSC (Spread spectrum clock) range [10] 0: No white noise. 1: Add white noise to spread waveform [11] When 1, future writes are ignored. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform-dptf | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-platform-dptf b/Documentation/ABI/testing/sysfs-platform-dptf index 141834342a4d..53c6b1000320 100644 --- a/Documentation/ABI/testing/sysfs-platform-dptf +++ b/Documentation/ABI/testing/sysfs-platform-dptf @@ -111,3 +111,43 @@ Contact: linux-acpi@vger.kernel.org Description: (RW) The PCH FIVR (Fully Integrated Voltage Regulator) switching frequency in MHz, when FIVR clock is 38.4MHz. + +What: /sys/bus/platform/devices/INTC1045:00/pch_fivr_switch_frequency/fivr_switching_freq_mhz +Date: September, 2021 +KernelVersion: v5.15 +Contact: linux-acpi@vger.kernel.org +Description: + (RO) Get the FIVR switching control frequency in MHz. + +What: /sys/bus/platform/devices/INTC1045:00/pch_fivr_switch_frequency/fivr_switching_fault_status +Date: September, 2021 +KernelVersion: v5.15 +Contact: linux-acpi@vger.kernel.org +Description: + (RO) Read the FIVR switching frequency control fault status. + +What: /sys/bus/platform/devices/INTC1045:00/pch_fivr_switch_frequency/ssc_clock_info +Date: September, 2021 +KernelVersion: v5.15 +Contact: linux-acpi@vger.kernel.org +Description: + (RO) Presents SSC (spread spectrum clock) information for EMI + (Electro magnetic interference) control. This is a bit mask. + Bits Description + [7:0] Sets clock spectrum spread percentage: + 0x00=0.2% , 0x3F=10% + 1 LSB = 0.1% increase in spread (for + settings 0x01 thru 0x1C) + 1 LSB = 0.2% increase in spread (for + settings 0x1E thru 0x3F) + [8] When set to 1, enables spread + spectrum clock + [9] 0: Triangle mode. FFC frequency + walks around the Fcenter in a linear + fashion + 1: Random walk mode. FFC frequency + changes randomly within the SSC + (Spread spectrum clock) range + [10] 0: No white noise. 1: Add white noise + to spread waveform + [11] When 1, future writes are ignored. |