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 F36F33C01; Fri, 27 Jun 2025 02:41:36 +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=1750992099; cv=none; b=e2eQE7Al8xw7MFiDG0Cdg++ImOHHzdB5PxqD1VEp6ky+lwFKi4u849VvqV85A/YASHiex7mgdZT8d/ilxaHnjBvR7sBKdpTlhtyhWXlFOqJmRvkl6vaa6qDQ263OGElkNRuUY7zdHkAlZLmX+eSn+LZI5OhpQLdTwtcLloJM+bM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750992099; c=relaxed/simple; bh=bjSC1GOvCkB3dcQCEkA48aQBF8HgMA07pqD3eC+Cjm4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WXuDVjDOqAKjO1KL9Azq1IKLwZW80iNelQolPjsb7ZchiAu8xE5BYz+TfgKDJER7pBV8ZAmX8DaVx+bXYn0eEdZzqpSbqs03uzYtYK2FdE+2uf3CqYoxNIJ7UXUj7kbQp/Nz3hf/FywGqdenwBIcPtIeRgxlctgYpy4X6Tmjy5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bgDrLief; 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="bgDrLief" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5433AC4CEEB; Fri, 27 Jun 2025 02:41:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750992096; bh=bjSC1GOvCkB3dcQCEkA48aQBF8HgMA07pqD3eC+Cjm4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bgDrLiefS/HPpb+VmjhqWsF1t3ouj5zOZkjYUHLP+B8J2HUb/gBySwAzVAc42xaKw YyYUfVbsiQREy9qluLwAfs/5IbNOKQFCw9OiG/mRW3V6ixjSPvS+ARDiYfxUlHAxd5 AyE5/GuwZ9VvD+2/OfNjWd8gezTvHMvNSDYlw+MK8WcCq7C8+VRI3qaIeH84gqX/pW /wTIa7k/khFtDOVEBoBxMaMRZ4FLtj6wIt+Er7yPQmvzx0MX9qYRsC8rdl0hlaPajX vh93FlroEXR6hjnJrR9Z12SRUzeRIWAS+1mr30IB99Ap1tdnpN0DQx2fbhfskjebJU nz/XvJyHxj2rA== Date: Thu, 26 Jun 2025 21:41:35 -0500 From: "Rob Herring (Arm)" To: Amit Kumar Mahapatra Cc: linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, git@amd.com, devicetree@vger.kernel.org, conor+dt@kernel.org, miquel.raynal@bootlin.com, krzk+dt@kernel.org, richard@nod.at, amitrkcian2002@gmail.com, vigneshr@ti.com Subject: Re: [PATCH v14 1/3] dt-bindings: mtd: Describe MTD partitions concatenation Message-ID: <175099209513.1650937.6817719319563715561.robh@kernel.org> References: <20250623105445.2394825-1-amit.kumar-mahapatra@amd.com> <20250623105445.2394825-2-amit.kumar-mahapatra@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20250623105445.2394825-2-amit.kumar-mahapatra@amd.com> On Mon, 23 Jun 2025 16:24:43 +0530, Amit Kumar Mahapatra wrote: > The AMD QSPI controller supports an advanced connection modes called > Stacked mode which allow the controller to treat two different flashes > as one storage. > > In Stacked connection mode flashes share the same SPI bus, but different CS > line, controller driver asserts the CS of the flash to which it needs to > communicate. Stacked mode is a software abstraction rather than a > controller feature or capability. At any given time, the controller > communicates with one of the two connected flash devices, as determined by > the requested address and data length. If an operation starts on one flash > and ends on the other, the mtd layer needs to split it into two separate > operations and adjust the data length accordingly. For more information on > the modes please feel free to go through the controller flash interface > below [1]. > > To support stacked mode, the existing MTD concat driver has been extended > to be more generic, enabling multiple sets of MTD partitions to be > virtually concatenated, with each set forming a distinct logical MTD > device. > > A new Device Tree property is introduced to facilitate this, containing > phandles of the partitions to be concatenated with the one where the > property is defined. This approach supports multiple sets of concatenated > partitions. > > [1] https://docs.amd.com/r/en-US/am011-versal-acap-trm/QSPI-Flash-Device-Interface > > Suggested-by: Miquel Raynal > Suggested-by: Rob Herring > Signed-off-by: Amit Kumar Mahapatra > --- > .../bindings/mtd/partitions/partition.yaml | 20 +++++++++++++++++++ > 1 file changed, 20 insertions(+) > Reviewed-by: Rob Herring (Arm)