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=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1887CC1975A for ; Thu, 12 Mar 2020 23:03:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7FE8206F1 for ; Thu, 12 Mar 2020 23:03:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="j0RzlUpF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726845AbgCLXDA (ORCPT ); Thu, 12 Mar 2020 19:03:00 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:33784 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726710AbgCLXDA (ORCPT ); Thu, 12 Mar 2020 19:03:00 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id A2B7F5F; Fri, 13 Mar 2020 00:02:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1584054177; bh=n1RmDaPINq/9UEwuYap1gQ4IHXGw18k1yY1Z161d2l8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j0RzlUpFWNePXY9BtYpu/R2uq3jNPUKgnQGwJF0K3Nz0EG3g4AuRS/fbjYO2/3ImW e8f0pYaoq5lQdcGdl0VaHfek8/F/HWkmijLUyU6rU0ujXnseBFkZ/CmAFDXCHGhcTh TF7GLUK33rMLlZhRKGreLMqV66Gg2tzb9p+WKG5E= Date: Fri, 13 Mar 2020 01:02:53 +0200 From: Laurent Pinchart To: Prabhakar Mahadev Lad Cc: Geert Uytterhoeven , Mauro Carvalho Chehab , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Rob Herring , Mark Rutland , Sakari Ailus , NXP Linux Team , Magnus Damm , Ezequiel Garcia , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Kernel Mailing List , Linux-Renesas , Fabio Estevam , Linux ARM , Linux Media Mailing List Subject: Re: [PATCH v2 2/3] media: i2c: ov5645: Switch to assigned-clock-rates Message-ID: <20200312230253.GB30932@pendragon.ideasonboard.com> References: <1584047552-20166-1-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com> <1584047552-20166-3-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Prabhakar, On Thu, Mar 12, 2020 at 09:52:38PM +0000, Prabhakar Mahadev Lad wrote: > On 12 March 2020 21:42, Geert Uytterhoeven wrote: > > On Thu, Mar 12, 2020 at 10:13 PM Lad Prabhakar wrote: > > > This patch switches to assigned-clock-rates for specifying the clock rate. > > > The clk-conf.c internally handles setting the clock rate when > > > assigned-clock-rates is passed. > > > > > > The driver now sets the clock frequency only if the deprecated > > > property clock-frequency is defined instead assigned-clock-rates, this > > > is to avoid breakage with existing DT binaries. > > > > > > Signed-off-by: Lad Prabhakar > > > > Thanks for your patch! > > > > > --- a/drivers/media/i2c/ov5645.c > > > +++ b/drivers/media/i2c/ov5645.c > > > @@ -1055,6 +1055,7 @@ static int ov5645_probe(struct i2c_client *client) > > > struct device_node *endpoint; > > > struct ov5645 *ov5645; > > > u8 chip_id_high, chip_id_low; > > > + bool set_clk = false; > > > unsigned int i; > > > u32 xclk_freq; > > > int ret; > > > @@ -1094,10 +1095,17 @@ static int ov5645_probe(struct i2c_client > > *client) > > > return PTR_ERR(ov5645->xclk); > > > } > > > > > > - ret = of_property_read_u32(dev->of_node, "clock-frequency", > > &xclk_freq); > > > + ret = of_property_read_u32(dev->of_node, "assigned-clock-rates", > > > + &xclk_freq); > > > if (ret) { > > > > I think you can just leave out the above check... > > > > > - dev_err(dev, "could not get xclk frequency\n"); > > > - return ret; > > > + /* check if deprecated property clock-frequency is defined */ > > > + ret = of_property_read_u32(dev->of_node, "clock-frequency", > > > + &xclk_freq); > > > + if (ret) { > > > > ... and ignore the absence of the deprecated property. > > > > > + dev_err(dev, "could not get xclk frequency\n"); > > > + return ret; > > > + } > > > + set_clk = true; > > > > I.e. just > > > > /* check if deprecated property clock-frequency is defined */ > > xclk_freq = 0; > > of_property_read_u32(dev->of_node, "clock-frequency", &xclk_freq); > > if (xclk_freq) { > > ret = clk_set_rate(ov5645->xclk, xclk_freq); > > if (ret) { > > dev_err(dev, "could not set xclk frequency\n"); > > return ret; > > } > > } else { > > xclk_freq = clk_get_rate(ov5645->xclk, xclk_freq); > > } > > > I did think about it initially, but realized the clk_get_rate may vary platform to platform > for example in G2E clk_get_rate() returns a frequency of 24242424 with > assigned-clock-rates set to 24000000 and probe would fail due to a check for > external clock must be 24MHz, with 1% tolerance. Then you need to handle the tolerance in this driver :-) > > > } > > > > > > /* external clock must be 24MHz, allow 1% tolerance */ @@ > > > -1107,10 +1115,12 @@ static int ov5645_probe(struct i2c_client *client) > > > return -EINVAL; > > > } > > > > > > - ret = clk_set_rate(ov5645->xclk, xclk_freq); > > > - if (ret) { > > > - dev_err(dev, "could not set xclk frequency\n"); > > > - return ret; > > > + if (set_clk) { > > > + ret = clk_set_rate(ov5645->xclk, xclk_freq); > > > + if (ret) { > > > + dev_err(dev, "could not set xclk frequency\n"); > > > + return ret; > > > + } > > > > > > } > > > > > > for (i = 0; i < OV5645_NUM_SUPPLIES; i++) -- Regards, Laurent Pinchart