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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3C46AC531DE for ; Thu, 15 Aug 2024 22:23:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=C50wtWFszrEYi0fLXo8fv4l6FOYydqFf0TSAexWaVQg=; b=ITpHgypVXWiEugCXMcrmKQrvCb H7I3bzxI56rk8mb3L6NqKlTAelSg+FyMu4YqvK8DAl7plT+xu3xQruuN1sN0XkYFxhHaP2itf+zuu N7w+R0GeVQuMXTQVvYbgu2v1+NvepY1kEePFSuAEhhm2wGjtAALWRYNXB5T979guTQd91uVkzcQMZ lRn819r3jSuTjQgrqPDiL5wz7VST4at5l2BWiexDYeV77foPkQYCMdiWJ9fu3+RQJZxpiACpxZtBf lZ6U+je3Qzhn+30XfNRv6x4OjiolWqmDfItWB3W68Le7j+JRtOoIMgX53xUh4pKeou+mGBtEHTvJZ +90ZsjSQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1seisg-0000000BBZB-1vsQ; Thu, 15 Aug 2024 22:23:42 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1seis2-0000000BBW5-1VHW for linux-arm-kernel@lists.infradead.org; Thu, 15 Aug 2024 22:23:03 +0000 Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 28277471; Fri, 16 Aug 2024 00:21:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1723760519; bh=PFdmgapN2g4RD/uxMXT/UTOpJWmDAeo1UG+kQusjXy8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sj3xJan18IFKXKGtebAcqFtGBeVlg1aLm04hUn2YFXbO6FVPvWb19sJAEdsYcOpYp nCkVhOYap6lEUOWIN2h2B3YxO82xlOTCXA/XgvKLrf29WNNHRwsJ1GrZTKbziVvwsd doj/JjoCmZ+y6CiDQrRdtLz4b5EOi363wcxhW9bc= Date: Fri, 16 Aug 2024 01:22:30 +0300 From: Laurent Pinchart To: Alexander Stein Cc: imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Adam Ford , Conor Dooley , Fabio Estevam , Krzysztof Kozlowski , Marek Vasut , Paul Elder , Peng Fan , Rob Herring , Sascha Hauer , Shawn Guo , Pengutronix Kernel Team , devicetree@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH] arm64: dts: imx8mp: Clarify csis clock frequency Message-ID: <20240815222230.GB23911@pendragon.ideasonboard.com> References: <20240813234010.17852-1-laurent.pinchart@ideasonboard.com> <3314370.44csPzL39Z@steina-w> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <3314370.44csPzL39Z@steina-w> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240815_152302_562448_98F7AD9E X-CRM114-Status: GOOD ( 21.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 15, 2024 at 02:12:09PM +0200, Alexander Stein wrote: > Am Mittwoch, 14. August 2024, 01:40:10 CEST schrieb Laurent Pinchart: > > The DT nodes for the MIPI CSI-2 receivers (MIPI_CSI) configure the > > CAM1_PIX and CAM2_PIX clocks to 266 MHz through the assigned-clock-rates > > property, and report that frequency in the clock-frequency property. The > > i.MX8MP reference manual and datasheet list 266 MHz as a nominal > > frequency when using both CSI-2 receivers, so all looks normal. > > > > In reality, the clock is actually set to 250 MHz, as the selected > > parent, IMX8MP_SYS_PLL2_1000M, has a 1/4 output that is selected as the > > closest frequency to 266 MHz. This doesn't break operation of the > > device, but is clearly misleading. > > > > Clarify the clock configuration by selecting the IMX8MP_SYS_PLL2_250M > > parent, dropping the redundant assigned-clock-rates, and setting > > clock-frequency to 250 MHz. This doesn't cause any functional change. > > > > Signed-off-by: Laurent Pinchart > > --- > > arch/arm64/boot/dts/freescale/imx8mp.dtsi | 10 ++++------ > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi > > index 603dfe80216f..d9b5c40f6460 100644 > > --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi > > +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi > > @@ -1687,7 +1687,7 @@ mipi_csi_0: csi@32e40000 { > > compatible = "fsl,imx8mp-mipi-csi2", "fsl,imx8mm-mipi-csi2"; > > reg = <0x32e40000 0x10000>; > > interrupts = ; > > - clock-frequency = <266000000>; > > + clock-frequency = <250000000>; > > This doesn't seem to be necessary, no? I can't be read from > IMX8MP_CLK_MEDIA_CAM1_PIX_ROOT. But oh well, that's what we have right now. I don't like the clock frequency property much, but as it's there, I decided to update it. Removing the property, if desired, belongs to a separate patch. > Despite that: > Reviewed-by: Alexander Stein > Tested-by: Alexander Stein Shawn, could you please pick this up for v6.12 ? > > clocks = <&clk IMX8MP_CLK_MEDIA_APB_ROOT>, > > <&clk IMX8MP_CLK_MEDIA_CAM1_PIX_ROOT>, > > <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF_ROOT>, > > @@ -1695,9 +1695,8 @@ mipi_csi_0: csi@32e40000 { > > clock-names = "pclk", "wrap", "phy", "axi"; > > assigned-clocks = <&clk IMX8MP_CLK_MEDIA_CAM1_PIX>, > > <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF>; > > - assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_1000M>, > > + assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_250M>, > > <&clk IMX8MP_CLK_24M>; > > - assigned-clock-rates = <266000000>; > > power-domains = <&media_blk_ctrl IMX8MP_MEDIABLK_PD_MIPI_CSI2_1>; > > status = "disabled"; > > > > @@ -1723,7 +1722,7 @@ mipi_csi_1: csi@32e50000 { > > compatible = "fsl,imx8mp-mipi-csi2", "fsl,imx8mm-mipi-csi2"; > > reg = <0x32e50000 0x10000>; > > interrupts = ; > > - clock-frequency = <266000000>; > > + clock-frequency = <250000000>; > > clocks = <&clk IMX8MP_CLK_MEDIA_APB_ROOT>, > > <&clk IMX8MP_CLK_MEDIA_CAM2_PIX_ROOT>, > > <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF_ROOT>, > > @@ -1731,9 +1730,8 @@ mipi_csi_1: csi@32e50000 { > > clock-names = "pclk", "wrap", "phy", "axi"; > > assigned-clocks = <&clk IMX8MP_CLK_MEDIA_CAM2_PIX>, > > <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF>; > > - assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_1000M>, > > + assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_250M>, > > <&clk IMX8MP_CLK_24M>; > > - assigned-clock-rates = <266000000>; > > power-domains = <&media_blk_ctrl IMX8MP_MEDIABLK_PD_MIPI_CSI2_2>; > > status = "disabled"; > > > > > > base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba -- Regards, Laurent Pinchart