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* [PATCH] ACPI: DPTF: Add new PCH FIVR methods
@ 2021-07-27 16:22 Srinivas Pandruvada
  2021-08-04 16:10 ` Rafael J. Wysocki
  0 siblings, 1 reply; 5+ messages in thread
From: Srinivas Pandruvada @ 2021-07-27 16:22 UTC (permalink / raw)
  To: rjw, lenb; +Cc: linux-acpi, linux-kernel, srinivas.pandruvada

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>
---
This commit was merged to 5.14 next tree, but later reverted. The
problem was not in this commit but reading attributes in general. This
is fixed by prior patch "ACPI: DPTF: Fix reading of attributes"

 Documentation/ABI/testing/sysfs-platform-dptf | 40 +++++++++++++++++++
 drivers/acpi/dptf/dptf_pch_fivr.c             |  9 +++++
 2 files changed, 49 insertions(+)

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.
diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c
index 550b9081fcbc..f4e9c2ef2f88 100644
--- a/drivers/acpi/dptf/dptf_pch_fivr.c
+++ b/drivers/acpi/dptf/dptf_pch_fivr.c
@@ -90,15 +90,24 @@ static ssize_t name##_store(struct device *dev,\
 
 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
+PCH_FIVR_SHOW(ssc_clock_info, GEMI)
+PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
+PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
 
 static DEVICE_ATTR_RW(freq_mhz_low_clock);
 static DEVICE_ATTR_RW(freq_mhz_high_clock);
+static DEVICE_ATTR_RO(ssc_clock_info);
+static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
+static DEVICE_ATTR_RO(fivr_switching_fault_status);
 
 static struct attribute *fivr_attrs[] = {
 	&dev_attr_freq_mhz_low_clock.attr,
 	&dev_attr_freq_mhz_high_clock.attr,
+	&dev_attr_ssc_clock_info.attr,
+	&dev_attr_fivr_switching_freq_mhz.attr,
+	&dev_attr_fivr_switching_fault_status.attr,
 	NULL
 };
 
-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: DPTF: Add new PCH FIVR methods
  2021-07-27 16:22 [PATCH] ACPI: DPTF: Add new PCH FIVR methods Srinivas Pandruvada
@ 2021-08-04 16:10 ` Rafael J. Wysocki
  0 siblings, 0 replies; 5+ messages in thread
From: Rafael J. Wysocki @ 2021-08-04 16:10 UTC (permalink / raw)
  To: Srinivas Pandruvada
  Cc: Rafael J. Wysocki, Len Brown, ACPI Devel Maling List,
	Linux Kernel Mailing List

On Tue, Jul 27, 2021 at 6:22 PM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> 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.
>                           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>
> ---
> This commit was merged to 5.14 next tree, but later reverted. The
> problem was not in this commit but reading attributes in general. This
> is fixed by prior patch "ACPI: DPTF: Fix reading of attributes"

Now applied as 5.15 material, thanks!

>  Documentation/ABI/testing/sysfs-platform-dptf | 40 +++++++++++++++++++
>  drivers/acpi/dptf/dptf_pch_fivr.c             |  9 +++++
>  2 files changed, 49 insertions(+)
>
> 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.
> diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c
> index 550b9081fcbc..f4e9c2ef2f88 100644
> --- a/drivers/acpi/dptf/dptf_pch_fivr.c
> +++ b/drivers/acpi/dptf/dptf_pch_fivr.c
> @@ -90,15 +90,24 @@ static ssize_t name##_store(struct device *dev,\
>
>  PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
>  PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
> +PCH_FIVR_SHOW(ssc_clock_info, GEMI)
> +PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
> +PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
>  PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
>  PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
>
>  static DEVICE_ATTR_RW(freq_mhz_low_clock);
>  static DEVICE_ATTR_RW(freq_mhz_high_clock);
> +static DEVICE_ATTR_RO(ssc_clock_info);
> +static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
> +static DEVICE_ATTR_RO(fivr_switching_fault_status);
>
>  static struct attribute *fivr_attrs[] = {
>         &dev_attr_freq_mhz_low_clock.attr,
>         &dev_attr_freq_mhz_high_clock.attr,
> +       &dev_attr_ssc_clock_info.attr,
> +       &dev_attr_fivr_switching_freq_mhz.attr,
> +       &dev_attr_fivr_switching_fault_status.attr,
>         NULL
>  };
>
> --
> 2.31.1
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: DPTF: Add new PCH FIVR methods
  2021-05-17 15:20 ` Rafael J. Wysocki
@ 2021-05-17 15:51   ` Srinivas Pandruvada
  0 siblings, 0 replies; 5+ messages in thread
From: Srinivas Pandruvada @ 2021-05-17 15:51 UTC (permalink / raw)
  To: Rafael J. Wysocki
  Cc: Rafael J. Wysocki, Len Brown, Linux Kernel Mailing List,
	ACPI Devel Maling List

On Mon, 2021-05-17 at 17:20 +0200, Rafael J. Wysocki wrote:
> On Mon, May 17, 2021 at 7:54 AM Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> 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.
> >                           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
> 
> I was about to apply this, but one question.
> 
> AFAICS the "show" function will simply evaluate GFCS and preset the
> returned value to the reader of the attribute, but the documentation
> says that this is the switching control frequency in MHz which
> doesn't
> seem to be consistent with the above information.
> 
> Is the reader of the attribute required to know the XTAL frequency
> and
> apply the above formula to the value read from it?  If so, the
> documentation should be clear about this.
> 
Since XTAL_FREQ can be different on designs, user of the interface is
supposed to know that.
I will update the documentation and resend.

Thanks,
Srinivas

> > [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>
> > ---
> >  Documentation/ABI/testing/sysfs-platform-dptf | 40
> > +++++++++++++++++++
> >  drivers/acpi/dptf/dptf_pch_fivr.c             |  9 +++++
> >  2 files changed, 49 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-platform-dptf
> > b/Documentation/ABI/testing/sysfs-platform-dptf
> > index 141834342a4d..f0c43711ad4f 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/fiv
> > r_switching_freq_mhz
> > +Date:          June, 2021
> > +KernelVersion: v5.14
> > +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/fiv
> > r_switching_fault_status
> > +Date:          June, 2021
> > +KernelVersion: v5.14
> > +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:          June, 2021
> > +KernelVersion: v5.14
> > +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.
> > diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c
> > b/drivers/acpi/dptf/dptf_pch_fivr.c
> > index 5fca18296bf6..22c4ae0401ef 100644
> > --- a/drivers/acpi/dptf/dptf_pch_fivr.c
> > +++ b/drivers/acpi/dptf/dptf_pch_fivr.c
> > @@ -55,15 +55,24 @@ static ssize_t name##_store(struct device
> > *dev,\
> > 
> >  PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
> >  PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
> > +PCH_FIVR_SHOW(ssc_clock_info, GEMI)
> > +PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
> > +PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
> >  PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
> >  PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
> > 
> >  static DEVICE_ATTR_RW(freq_mhz_low_clock);
> >  static DEVICE_ATTR_RW(freq_mhz_high_clock);
> > +static DEVICE_ATTR_RO(ssc_clock_info);
> > +static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
> > +static DEVICE_ATTR_RO(fivr_switching_fault_status);
> > 
> >  static struct attribute *fivr_attrs[] = {
> >         &dev_attr_freq_mhz_low_clock.attr,
> >         &dev_attr_freq_mhz_high_clock.attr,
> > +       &dev_attr_ssc_clock_info.attr,
> > +       &dev_attr_fivr_switching_freq_mhz.attr,
> > +       &dev_attr_fivr_switching_fault_status.attr,
> >         NULL
> >  };
> > 
> > --
> > 2.27.0
> > 



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] ACPI: DPTF: Add new PCH FIVR methods
  2021-05-17  5:53 Srinivas Pandruvada
@ 2021-05-17 15:20 ` Rafael J. Wysocki
  2021-05-17 15:51   ` Srinivas Pandruvada
  0 siblings, 1 reply; 5+ messages in thread
From: Rafael J. Wysocki @ 2021-05-17 15:20 UTC (permalink / raw)
  To: Srinivas Pandruvada
  Cc: Rafael J. Wysocki, Len Brown, Linux Kernel Mailing List,
	ACPI Devel Maling List

On Mon, May 17, 2021 at 7:54 AM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> 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.
>                           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

I was about to apply this, but one question.

AFAICS the "show" function will simply evaluate GFCS and preset the
returned value to the reader of the attribute, but the documentation
says that this is the switching control frequency in MHz which doesn't
seem to be consistent with the above information.

Is the reader of the attribute required to know the XTAL frequency and
apply the above formula to the value read from it?  If so, the
documentation should be clear about this.

> [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>
> ---
>  Documentation/ABI/testing/sysfs-platform-dptf | 40 +++++++++++++++++++
>  drivers/acpi/dptf/dptf_pch_fivr.c             |  9 +++++
>  2 files changed, 49 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-platform-dptf b/Documentation/ABI/testing/sysfs-platform-dptf
> index 141834342a4d..f0c43711ad4f 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:          June, 2021
> +KernelVersion: v5.14
> +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:          June, 2021
> +KernelVersion: v5.14
> +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:          June, 2021
> +KernelVersion: v5.14
> +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.
> diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c
> index 5fca18296bf6..22c4ae0401ef 100644
> --- a/drivers/acpi/dptf/dptf_pch_fivr.c
> +++ b/drivers/acpi/dptf/dptf_pch_fivr.c
> @@ -55,15 +55,24 @@ static ssize_t name##_store(struct device *dev,\
>
>  PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
>  PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
> +PCH_FIVR_SHOW(ssc_clock_info, GEMI)
> +PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
> +PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
>  PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
>  PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
>
>  static DEVICE_ATTR_RW(freq_mhz_low_clock);
>  static DEVICE_ATTR_RW(freq_mhz_high_clock);
> +static DEVICE_ATTR_RO(ssc_clock_info);
> +static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
> +static DEVICE_ATTR_RO(fivr_switching_fault_status);
>
>  static struct attribute *fivr_attrs[] = {
>         &dev_attr_freq_mhz_low_clock.attr,
>         &dev_attr_freq_mhz_high_clock.attr,
> +       &dev_attr_ssc_clock_info.attr,
> +       &dev_attr_fivr_switching_freq_mhz.attr,
> +       &dev_attr_fivr_switching_fault_status.attr,
>         NULL
>  };
>
> --
> 2.27.0
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH] ACPI: DPTF: Add new PCH FIVR methods
@ 2021-05-17  5:53 Srinivas Pandruvada
  2021-05-17 15:20 ` Rafael J. Wysocki
  0 siblings, 1 reply; 5+ messages in thread
From: Srinivas Pandruvada @ 2021-05-17  5:53 UTC (permalink / raw)
  To: rjw, lenb; +Cc: linux-kernel, linux-acpi, Srinivas Pandruvada

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>
---
 Documentation/ABI/testing/sysfs-platform-dptf | 40 +++++++++++++++++++
 drivers/acpi/dptf/dptf_pch_fivr.c             |  9 +++++
 2 files changed, 49 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-platform-dptf b/Documentation/ABI/testing/sysfs-platform-dptf
index 141834342a4d..f0c43711ad4f 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:		June, 2021
+KernelVersion:	v5.14
+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:		June, 2021
+KernelVersion:	v5.14
+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:		June, 2021
+KernelVersion:	v5.14
+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.
diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c
index 5fca18296bf6..22c4ae0401ef 100644
--- a/drivers/acpi/dptf/dptf_pch_fivr.c
+++ b/drivers/acpi/dptf/dptf_pch_fivr.c
@@ -55,15 +55,24 @@ static ssize_t name##_store(struct device *dev,\
 
 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
+PCH_FIVR_SHOW(ssc_clock_info, GEMI)
+PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
+PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
 
 static DEVICE_ATTR_RW(freq_mhz_low_clock);
 static DEVICE_ATTR_RW(freq_mhz_high_clock);
+static DEVICE_ATTR_RO(ssc_clock_info);
+static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
+static DEVICE_ATTR_RO(fivr_switching_fault_status);
 
 static struct attribute *fivr_attrs[] = {
 	&dev_attr_freq_mhz_low_clock.attr,
 	&dev_attr_freq_mhz_high_clock.attr,
+	&dev_attr_ssc_clock_info.attr,
+	&dev_attr_fivr_switching_freq_mhz.attr,
+	&dev_attr_fivr_switching_fault_status.attr,
 	NULL
 };
 
-- 
2.27.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-08-04 16:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-27 16:22 [PATCH] ACPI: DPTF: Add new PCH FIVR methods Srinivas Pandruvada
2021-08-04 16:10 ` Rafael J. Wysocki
  -- strict thread matches above, loose matches on Subject: below --
2021-05-17  5:53 Srinivas Pandruvada
2021-05-17 15:20 ` Rafael J. Wysocki
2021-05-17 15:51   ` Srinivas Pandruvada

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