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 CB9311D556; Tue, 11 Jun 2024 17:10:56 +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=1718125856; cv=none; b=UFPCflXEi4dFFABun9kl+QQU5EJisJ46bSqK49GaAIK691Fb2cRdP5vEWbNIGYznzNuoVuQn8P9gGQDFPhYRhQbLiA4dMwaAzoFRvkziUubqVkqQTVPLD4GAvjJptCEykMFJ3+gBUuBg/9jHbOxfIrxol2y0KcBzx5reIfre3P0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718125856; c=relaxed/simple; bh=gFYHyJOp+GLvLO8caFrC+bAJxiiQYs3SDuhR95Pp0qo=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=mc9JQ2KWoJEfQeC+nYGulwXzZhAlfhXkCHxOhPbLjBXsDN5YhM5qzlWrqex2jJi/O5R7/QrHYYPiwU6qGNe69EWAiYgSwXlSjruZWKbUfi+507gxXVxD/YqE/KOYDNU920BCJ+bul/EU+z3/WHSZTrFhxZd/51gyT+JMGWrPyFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rrKsbTQu; 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="rrKsbTQu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A9CBC2BD10; Tue, 11 Jun 2024 17:10:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718125856; bh=gFYHyJOp+GLvLO8caFrC+bAJxiiQYs3SDuhR95Pp0qo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=rrKsbTQu+g8sy3y1sNoL/1cLUJzwsI+jSnaeJF/MUDr9qBxDOXI6yVew9zke6UlYs Niwyn9lfbTuT9Cr+QujfSQQaieXHLWYZh8rj7ssbarEupC2Bv9YsZPcMBG8kEBJPd/ rkjLST5yzg4X8QJWMXnjfCELmLrrgbuPsFerKYAYDP2FBD5vq9FJW4/rSVDGwLTN6x QzCcItvo6D4CYccoG8wXEpusNaq9STs0AOH6kH5KHTJm/5rmKxbH9ZN6UYu9MuQcMJ URp2sqtJbHh5fD7Xt5Ks4nOMQ7g3u4aGSYpsXvt5xO+iMbHTGBJDxXbI6vifW1gyAI U/Slc4E54/X0g== Date: Tue, 11 Jun 2024 12:10:54 -0500 From: Bjorn Helgaas To: Conor Dooley Cc: conor@kernel.org, Daire McNamara , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Krzysztof Kozlowski , Conor Dooley , linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v1 2/2] PCI: microchip: rework reg region handing Message-ID: <20240611171054.GA989979@bhelgaas> Precedence: bulk X-Mailing-List: devicetree@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: <20240527-flint-whacky-4fb21c38476b@wendy> On Mon, May 27, 2024 at 10:37:17AM +0100, Conor Dooley wrote: > The PCI host controller on PolarFire SoC has multiple "instances", each > with their own bridge and ctrl address spaces. The original binding has > an "apb" register region, and it is expected to be set to the base > address of the host controllers register space. Defines in the driver > were used to compute the addresses of the bridge and ctrl address ranges > corresponding to instance1. Some customers want to use instance0 however > and that requires changing the defines in the driver, which is clearly > not a portable solution. > > The binding has been changed from a single register region to a pair, > corresponding to the bridge and ctrl regions respectively, so modify the > driver to read these regions directly from the devicetree rather than > compute them from the base address of the abp region. > > To maintain backwards compatibility with the existing binding, the > driver retains code to handle the "abp" reg and computes the base > address of the bridge and ctrl regions using the defines if it is > present. reg-names has always been a required property, so this is > safe to do. When you update this, can you add something about the objective to the subject line? "rework reg region handling" just says "we did something", but not why or what the benefit is. The cover letter ("support using either instance 1 or 2") has good information that could be part of this. Bjorn