Home
last modified time | relevance | path

Searched hist:"7 a6226db" (Results 1 – 2 of 2) sorted by relevance

/openbmc/linux/drivers/acpi/dptf/
H A Ddptf_pch_fivr.c7a6226db Tue Jul 27 11:22:40 CDT 2021 Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> 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>
/openbmc/linux/Documentation/ABI/testing/
H A Dsysfs-platform-dptf7a6226db Tue Jul 27 11:22:40 CDT 2021 Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> 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>