From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E3A1161914; Tue, 7 May 2024 15:15:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715094935; cv=none; b=SAeASRx6DGtHNLU7eKuU7xj8OZA4QObBEJR+sNgE8wEVGZ6MQ+ZmhuW+l3Y4U/OuY6yC634HlwMs/oNHctCFeVZIDyRN4NJ5yxhAUds1kKklVqEFYdAToxtN/Q9Si2ZKpCTdYeicrtSTKTN/CQuf7lTC1jfKb5aUNA4nXbr4RVk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715094935; c=relaxed/simple; bh=AF0IG7U9yLaf0TKDjmv2oW0NAZ5Yv6qM/EdNBZdaA+M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mlVw9IiUfBF1wfQKbuFtX3twj1dIX2BJhw316lCgSaRzfO7SNA42mHAgr9qfx9KkkvOv5n9Mn9o2WxdaiAR4Sa2Ft9yo/XDKNC6zcMfpyLYXWmzBftwJdAi2hwo3NDs02m1LAo6g3bGAom5bHxhlsxquJqkpJcgHCoxtnEviAqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N5bYQe1y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N5bYQe1y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F331C2BBFC; Tue, 7 May 2024 15:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715094934; bh=AF0IG7U9yLaf0TKDjmv2oW0NAZ5Yv6qM/EdNBZdaA+M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=N5bYQe1yIl5osdfHFh58czWgmEpherJOCYDFqdQqTSJ7s9wfmt+AOOJ1/l4Q3g7qJ vTYfylx128AP7P4/AAQsV3/EN5mNgSQCUu+TZqLAKJuSPeeId8hMMt3GIHGzoH4QDi kOL+KBP9mQb98GY7LtAVJgqC3Tvg8blVd/wK7KReF/KwDNCbcWbXk3Fs3sO/D6F6ly txyM8vZoxtvQ100G2Y65/qu5S2X/GfOj6BGaLAuQQdJu5r4AR8KnDAmPDE2lTl1s36 hSLVUzZkp0CyUMG88QDwF59bHtFI9sMLAu250o1l8Od8kJLkOQOXJjQUDUTgoPx5OD 5frM4STFkxL8Q== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1s4MXY-000000004ZW-2wmP; Tue, 07 May 2024 17:15:36 +0200 Date: Tue, 7 May 2024 17:15:36 +0200 From: Johan Hovold To: Andy Shevchenko Cc: Johan Hovold , Lee Jones , Mark Brown , Linus Walleij , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Liam Girdwood , Das Srinagesh , Satya Priya , Stephen Boyd , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org Subject: Re: [PATCH 03/13] mfd: pm8008: deassert reset on probe Message-ID: References: <20240506150830.23709-1-johan+linaro@kernel.org> <20240506150830.23709-4-johan+linaro@kernel.org> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, May 06, 2024 at 09:57:07PM +0300, Andy Shevchenko wrote: > Mon, May 06, 2024 at 05:08:20PM +0200, Johan Hovold kirjoitti: > > Request and deassert any (optional) reset gpio during probe in case it > > has been left asserted by the boot firmware. > > > > Note the reset line is not asserted to avoid reverting to the default > > I2C address in case the firmware has configured an alternate address. > > ... > > > + reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > > + if (IS_ERR(reset)) > > + return PTR_ERR(reset); > > Shouldn't you wait a bit to make chip settle down? Yeah, probably. I actually asserted reset here for a while (e.g. to reset the address), but didn't have to use a post-reset delay then. I'll see if I can find someone with access to a datasheet or maybe add some small delay here anyway. Johan