From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH v9 07/22] clk: Add API to get index of the clock parent Date: Wed, 06 Nov 2019 15:10:05 -0800 Message-ID: <20191106231005.F2CD820869@mail.kernel.org> References: <1565984527-5272-1-git-send-email-skomatineni@nvidia.com> <1565984527-5272-8-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1565984527-5272-8-git-send-email-skomatineni@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: jason@lakedaemon.net, jonathanh@nvidia.com, linus.walleij@linaro.org, marc.zyngier@arm.com, mark.rutland@arm.com, stefan@agner.ch, tglx@linutronix.de, thierry.reding@gmail.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, skomatineni@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, digetx@gmail.com, devicetree@vger.kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, linux-pm@vger.kernel.org List-Id: linux-tegra@vger.kernel.org Quoting Sowjanya Komatineni (2019-08-16 12:41:52) > This patch adds an API clk_hw_get_parent_index to get index of the > clock parent to use during the clock restore operations on system > resume. Is there a reason we can't save the clk hw index at suspend time by reading the hardware to understand the current parent? The parent index typically doesn't matter unless we're trying to communicate something from the framework to the provider driver. Put another way, I would think the provider driver can figure out the index itself without having to go through the framework to do so. >=20 > Reviewed-by: Thierry Reding > Reviewed-by: Dmitry Osipenko > Signed-off-by: Sowjanya Komatineni > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index cbcc333aec84..12ad0e9b8591 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1645,6 +1645,23 @@ static int clk_fetch_parent_index(struct clk_core = *core, > return i; > } > =20 > +/** > + * clk_hw_get_parent_index - return the index of parent clock > + * @hw: clk_hw associated with the clk being consumed > + * @parent_hw: clk_hw associated with the parent of clk > + * > + * Fetches and returns the index of parent clock. > + * If hw or parent_hw is NULL, returns -EINVAL. > + */ > +int clk_hw_get_parent_index(struct clk_hw *hw, struct clk_hw *parent_hw) > +{ > + if (!hw || !parent_hw) > + return -EINVAL; The caller should be ashamed if they call this with NULL arguments. I'd prefer we skip this check and we get an oops. > + > + return clk_fetch_parent_index(hw->core, parent_hw->core); > +} > +EXPORT_SYMBOL_GPL(clk_hw_get_parent_index); > + > /* > * Update the orphan status of @core and all its children. > */ 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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 35158FC6194 for ; Wed, 6 Nov 2019 23:10:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0658621848 for ; Wed, 6 Nov 2019 23:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573081811; bh=phPqrB8jdcQhMXpI7PNcLtByNjzRwAfdzJcKYVWr13E=; h=In-Reply-To:References:Subject:From:To:Cc:Date:List-ID:From; b=kHmgzdx9yPDTamRpuyhdHhsdB1RX9Gg0zQm98d3kQu/vHbRy1Ny7ib9/XiAoXalnj wMGzcd5yWoCTWujJc2e8/OrDpTbE+yzAtSU/JX2/X884TzM8DQhGsnygIlm+Vajnaa aJSHWnhIJIVPz/JlREMUOfhGYkg0MxyFmaDxbd5I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727487AbfKFXKH (ORCPT ); Wed, 6 Nov 2019 18:10:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:34466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727228AbfKFXKH (ORCPT ); Wed, 6 Nov 2019 18:10:07 -0500 Received: from kernel.org (unknown [104.132.0.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F2CD820869; Wed, 6 Nov 2019 23:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573081806; bh=phPqrB8jdcQhMXpI7PNcLtByNjzRwAfdzJcKYVWr13E=; h=In-Reply-To:References:Subject:From:To:Cc:Date:From; b=Ujuxe6X1kCsRkxtdQYgSWiR0mYrSc9nQP1ygJUr45CCctRkVEX2Jf9Wnp4kkOvTVm GBOqu/HNFeA6cJMT7QS6PMnl2OKfLo3pUAUZ0MAZ1yEG1+KPhxkjhqPb0cTze2UIjW qce2kBf6A/GX0fvsfQmdvN+ylBBREGi5gRasWjRE= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <1565984527-5272-8-git-send-email-skomatineni@nvidia.com> References: <1565984527-5272-1-git-send-email-skomatineni@nvidia.com> <1565984527-5272-8-git-send-email-skomatineni@nvidia.com> Subject: Re: [PATCH v9 07/22] clk: Add API to get index of the clock parent From: Stephen Boyd To: Sowjanya Komatineni , jason@lakedaemon.net, jonathanh@nvidia.com, linus.walleij@linaro.org, marc.zyngier@arm.com, mark.rutland@arm.com, stefan@agner.ch, tglx@linutronix.de, thierry.reding@gmail.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, skomatineni@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, digetx@gmail.com, devicetree@vger.kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, linux-pm@vger.kernel.org User-Agent: alot/0.8.1 Date: Wed, 06 Nov 2019 15:10:05 -0800 Message-Id: <20191106231005.F2CD820869@mail.kernel.org> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Quoting Sowjanya Komatineni (2019-08-16 12:41:52) > This patch adds an API clk_hw_get_parent_index to get index of the > clock parent to use during the clock restore operations on system > resume. Is there a reason we can't save the clk hw index at suspend time by reading the hardware to understand the current parent? The parent index typically doesn't matter unless we're trying to communicate something from the framework to the provider driver. Put another way, I would think the provider driver can figure out the index itself without having to go through the framework to do so. >=20 > Reviewed-by: Thierry Reding > Reviewed-by: Dmitry Osipenko > Signed-off-by: Sowjanya Komatineni > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index cbcc333aec84..12ad0e9b8591 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1645,6 +1645,23 @@ static int clk_fetch_parent_index(struct clk_core = *core, > return i; > } > =20 > +/** > + * clk_hw_get_parent_index - return the index of parent clock > + * @hw: clk_hw associated with the clk being consumed > + * @parent_hw: clk_hw associated with the parent of clk > + * > + * Fetches and returns the index of parent clock. > + * If hw or parent_hw is NULL, returns -EINVAL. > + */ > +int clk_hw_get_parent_index(struct clk_hw *hw, struct clk_hw *parent_hw) > +{ > + if (!hw || !parent_hw) > + return -EINVAL; The caller should be ashamed if they call this with NULL arguments. I'd prefer we skip this check and we get an oops. > + > + return clk_fetch_parent_index(hw->core, parent_hw->core); > +} > +EXPORT_SYMBOL_GPL(clk_hw_get_parent_index); > + > /* > * Update the orphan status of @core and all its children. > */