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 85F13C7EE30 for ; Fri, 27 Jun 2025 02:41:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dJV0eHZpVmxdD75IbvA2P/s34Ay+HgEP6GSBfWKZB0Y=; b=ruNxLEiCF0lQKw X3yJjNsCrD89kY3PWLE7QZtADJUpqh00J+DNLHvo9x/RVBPgcKUttzBlidO1i6G8JhSK9CzUlY5X9 eHQTIdnfRod09wUtlg7KqJQsQZfzTY9AOJ1QxO+/jgc5HDmHWN6WuQjKdmA8vrK0/QjDisCYJZH++ 2ULC+WMVTahr4X/ebyqhvYy0ZKNhWNMLWnpu4RB17cxCsV8SKj97TVrqwua7S9Hr1KVgSi7YC1VMg BwN68dSJ4ps3wLsm55CSlBQxUfgNixbfrJjl3ESVM1fog+8asxTWgSvtRWCVK9hmGNSa1j+PKZoNZ IoR4opd2JiMUlgsOQ7nA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUz24-0000000DMyo-16hl; Fri, 27 Jun 2025 02:41:40 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUz21-0000000DMyU-2bgt for linux-mtd@lists.infradead.org; Fri, 27 Jun 2025 02:41:39 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id CBB94A52140; Fri, 27 Jun 2025 02:41:36 +0000 (UTC) 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> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250623105445.2394825-2-amit.kumar-mahapatra@amd.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250626_194137_725081_DFF9F3AA X-CRM114-Status: GOOD ( 16.99 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org 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) ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/