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 6A503C3ABC3 for ; Fri, 9 May 2025 06:34:50 +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=NpLhIi7Kz6CQZ4yMzp2mUBrSEQXZDgA4zptLKbGKRLc=; b=1uH5AV0wAGczVDTVHsMyne9Cza 6kdYOEgQapixPvZj9rbsS2tN7ZEeHTHUk85FMGQOnIxE5Ambrzgxev4gzuPalS2YAgxftRhiF2hOQ W3bkxslUNqNsfb7iwdJGAVE5xZlo245lqtk5DrXwI+E7AOZOquAaGSeDs85AJCdgSjRYI/HmvEnH4 lJmf1Rz7nFS2/o/T6AIB1Vq1VvS1JQrdihG6LKFXC8Ka1UUGi7113bxjaHabWjbvgE74fij5xXF5x vLq+GIpp5nMTv3N8k62F2xT98NmPPkuevEpvorOQ/qnsF5vSWNP3LfQdUGgw/37M3Fz5Upial3HuU HgnsIT4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uDHJi-00000002cJr-1zyP; Fri, 09 May 2025 06:34:42 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uDHHf-00000002c2E-3aA9 for linux-arm-kernel@lists.infradead.org; Fri, 09 May 2025 06:32:37 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uDHHR-00046g-Ca; Fri, 09 May 2025 08:32:21 +0200 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uDHHQ-001qPI-1J; Fri, 09 May 2025 08:32:20 +0200 Received: from sha by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1uDHHQ-00CHwN-0v; Fri, 09 May 2025 08:32:20 +0200 Date: Fri, 9 May 2025 08:32:20 +0200 From: Sascha Hauer To: Nishanth Menon Cc: Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: dts: ti: k3-am625-sk: Add power/temperature sensors Message-ID: References: <20250505-am625-sk-sensors-v1-1-688fb928b390@pengutronix.de> <20250507120104.4mhuaabe5auukarn@banter> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250507120104.4mhuaabe5auukarn@banter> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250508_233235_893984_1429D7E7 X-CRM114-Status: GOOD ( 30.45 ) 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 Hi Nishanth, On Wed, May 07, 2025 at 07:01:04AM -0500, Nishanth Menon wrote: > On 15:24-20250505, Sascha Hauer wrote: > > The AM625-SK has six power sensors and two temperature sensors connected > > to I2C. Add them to the device tree. > > > > Signed-off-by: Sascha Hauer > > --- > > The AM625-SK has six power sensors and two temperature sensors connected > > to I2C. Add them to the device tree. > > Sascha, > > I suggest making this as overlay. The reason is as follows: AM625-SK > among other TI evms do have automated power measurement capability from > XDS110 (accessible via USB port for jtag - appears as a rudimentary > menu option). The way this works is that it uses TM4C1294NCPDT to use > I2C commands to control the INA226/231 depending on the evm. > > This firmware should be flashed by default on production boards (if > not, starting up CCS[1], autodetects older firmware and updates - at > least to my understanding) - by the way, this firmware also does test > automation, such as boot mode switch control, reset control etc. > > This is the primary framework meant to be used by test automation and > indeed it is the default inside TI. > > Challenge here is this: if we make this default in Linux, the test > automation system configures the INA226/231 in a different sampling > mode depending on usecase etc Vs what Linux does (even though the > shunt and the bus voltage for a given INA is the same). And just like > Linux, the firmware power measurement logic has changed over the > years. > > Anyways, while I know that the SoC and TM4C can both handle > multi-master, the challenge is the same INA controlled and > mix-configured by two masters (and there is no synchronization between > the two). > > To avoid this entire conflict and headache, I suggest adding it as > overlay that can be applied depending on the preference of measurement > desired. Thanks for this explanation. I'll go for the overlay then. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |