From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CA52C433B4 for ; Mon, 17 May 2021 16:15:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A6F061057 for ; Mon, 17 May 2021 16:15:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345922AbhEQQQ0 (ORCPT ); Mon, 17 May 2021 12:16:26 -0400 Received: from mga07.intel.com ([134.134.136.100]:40796 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346138AbhEQP6K (ORCPT ); Mon, 17 May 2021 11:58:10 -0400 IronPort-SDR: BMA++xii8SwWkuPQgi3E2LmxOrBecr3H3QEcY3tnSY2syTEhgWwDedY4c6yahQ4O1snsmPqNoY 2Hqg77LZJh5w== X-IronPort-AV: E=McAfee;i="6200,9189,9987"; a="264409952" X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="264409952" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 08:51:30 -0700 IronPort-SDR: dq2q+9+jFCNc1GGOtlyxbC0N52q2GurHuwma66S/ls+dO1hgr45Vtd0OpX9s29l7lPKBuXJZdO vIGrK/k76raA== X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="410875570" Received: from btamaklo-mobl.amr.corp.intel.com ([10.209.149.190]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 08:51:27 -0700 Message-ID: Subject: Re: [PATCH] ACPI: DPTF: Add new PCH FIVR methods From: Srinivas Pandruvada To: "Rafael J. Wysocki" Cc: "Rafael J. Wysocki" , Len Brown , Linux Kernel Mailing List , ACPI Devel Maling List Date: Mon, 17 May 2021 08:51:23 -0700 In-Reply-To: References: <20210517055356.1918418-1-srinivas.pandruvada@linux.intel.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-05-17 at 17:20 +0200, Rafael J. Wysocki wrote: > On Mon, May 17, 2021 at 7:54 AM Srinivas Pandruvada > 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 > >