On Tue, May 18, 2021 at 12:27 PM Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > On Tue, 2021-05-18 at 11:36 +0200, Rafael J. Wysocki wrote: > > On Tue, May 18, 2021 at 5:42 AM Srinivas Pandruvada > > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote: > > > > > > 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 > > > using ACPI method GFCS. Refer to the > > > documentation for the equation. > > > 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@xxxxxxxxxxxxxxx> > > > --- > > > v2 > > > Update documentation for fivr_switching_freq_mhz > > > > > > Documentation/ABI/testing/sysfs-platform-dptf | 42 > > > +++++++++++++++++++ > > > drivers/acpi/dptf/dptf_pch_fivr.c | 9 ++++ > > > 2 files changed, 51 insertions(+) > > > > > > diff --git a/Documentation/ABI/testing/sysfs-platform-dptf > > > b/Documentation/ABI/testing/sysfs-platform-dptf > > > index 141834342a4d..fe62f024eb93 100644 > > > --- a/Documentation/ABI/testing/sysfs-platform-dptf > > > +++ b/Documentation/ABI/testing/sysfs-platform-dptf > > > @@ -111,3 +111,45 @@ Contact: linux-acpi@xxxxxxxxxxxxxxx > > > 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/fiv > > > r_switching_freq_mhz > > > +Date: June, 2021 > > > +KernelVersion: v5.14 > > > +Contact: linux-acpi@xxxxxxxxxxxxxxx > > > +Description: > > > + (RO) Get the FIVR switching control frequency in > > > MHz after applying equation > > > + "fivr_switching_freq_mhz * XTAL_FREQ / 128". Here > > > XTAL_FREQ is Crystal Oscillator frequency > > > + in MHz, which is product specific. > > > > IMO it would be sufficient to say the following here: > > > > + (RO) PCH FIVR switching control frequency in the > > units > > of XTAL_FREQ / 128, > > + where XTAL_FREQ is the Crystal Oscillator frequency > > (product specific). > > > > This means that it needs to be multiplied by XTAL_FREQ / 128 to get > > the frequency in the whatever units XTAL_FREQ is expressed. > > > Looks good. So applied as 5.14 material, thanks!
