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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 446BEE80AAD for ; Wed, 27 Sep 2023 14:00:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232000AbjI0OAd (ORCPT ); Wed, 27 Sep 2023 10:00:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231758AbjI0OAc (ORCPT ); Wed, 27 Sep 2023 10:00:32 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7734AFC; Wed, 27 Sep 2023 07:00:31 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 54CB31FB; Wed, 27 Sep 2023 07:01:09 -0700 (PDT) Received: from bogus (unknown [10.57.37.227]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B9D0A3F59C; Wed, 27 Sep 2023 07:00:29 -0700 (PDT) Date: Wed, 27 Sep 2023 14:59:09 +0100 From: Sudeep Holla To: "lihuisong (C)" Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org, Sudeep Holla , "Rafael J. Wysocki" , Andi Shyti , Jean Delvare , Guenter Roeck Subject: Re: [PATCH 1/3] ACPI: PCC: Add PCC shared memory region command and status bitfields Message-ID: <20230927135909.6rssuywmj4k3odex@bogus> References: <20230926-pcc_defines-v1-0-0f925a1658fd@arm.com> <20230926-pcc_defines-v1-1-0f925a1658fd@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On Wed, Sep 27, 2023 at 10:07:15AM +0800, lihuisong (C) wrote: > Hi Sudeep, > > 在 2023/9/26 20:28, Sudeep Holla 写道: > > Define the common macros to use when referring to various bitfields in > > the PCC generic communications channel command and status fields. > > Can you define the bit0 macros in the "flags" for Extended PCC Subspace > Shared Memory Region? Sure I will take a look and include it in v2 if applicable. > > > > Currently different drivers that need to use these bitfields have defined > > these locally. This common macro is intended to consolidate and replace > > those. > > > > Cc: Rafael J. Wysocki > > Signed-off-by: Sudeep Holla > > --- > > include/acpi/pcc.h | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h > > index 73e806fe7ce7..66d9934c2ee4 100644 > > --- a/include/acpi/pcc.h > > +++ b/include/acpi/pcc.h > > @@ -18,7 +18,18 @@ struct pcc_mbox_chan { > > u16 min_turnaround_time; > > }; > > +/* Generic Communications Channel Shared Memory Region */ > > +#define PCC_SIGNATURE 0x50424300 > Why is this signature 0x50424300? It is as per the specification. > In ACPI spec, this signature is all 0x50434303. No, not exactly. It is just an example. The PCC signature - The signature of a subspace is computed by a bitwise-or of the value 0x50434300 with the subspace ID. For example, subspace 3 has signature 0x50434303 And I see the driver you mentioned(drivers/soc/hisilicon/kunpeng_hccs.c) is doing the right thing. I am bit confused as why you being the author of the driver are now confused. -- Regards, Sudeep