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 E566AC5AE59 for ; Thu, 5 Jun 2025 14:09:12 +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=bzOwVxAvD7D9iulEupKxTvZo9L3dhirUMCqyZoJiCbQ=; b=T1OUhm0B0DM9Zm B6faRDCKcM/sXQrs3xNfwn2Zb56RPboGuGNQo8S0wxOwwO1H1UM2GGVuTEYnY8mHjfaIlGBfHgjlK SupYW41nZNwCF945kt2T+GLgX4nMeqc5t8hyFlXJ1VqO6wq2GPFvPYrNTpMetjpHTzstHj7oMLfX3 vICHyBwZVvucIIDtEQmqZI8YBbaeTMJBmsLOzcSiisaajNoSaYfKHyUPmQekWAvb7ndEBoWDOdbNa RovBpy/SmYfamPKhgVEie3AbsOycdCsmSAu7lCG6ZbIO+SeyMzlH7OJDGmRQ08MalWjctVR4vYHXx 9YZX/ejdZmxqq3hl1ciQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uNBHF-0000000Fjh8-1eWy; Thu, 05 Jun 2025 14:09:05 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uNAwQ-0000000FhFH-0iFx for linux-mtd@lists.infradead.org; Thu, 05 Jun 2025 13:47:36 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id DC29249EA8; Thu, 5 Jun 2025 13:47:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8273CC4CEE7; Thu, 5 Jun 2025 13:47:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749131253; bh=E9UAI5/sHcwgTTNJ9bwD0qg+BJ3oUIA5vyBcIyxvHu4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Jmdri2IOjk0732jc3DNoUQJM1nSm0hqSQxNSfR7rTBu0IR80Ay9p7es5CDUc/rHIo /jsyD999SdJ6cTBNSVNtugt6XJAYCSsN6UePi/DwO3KhYURdgfh9rmmv+SEcLVsaKp LzZJFu9Q3enHClb52Mym9E2s9XFt4h0mtkep0UXbcj+0a0FqYgrob1C0C0aFbSCCVn xHhSFFw4EQLTEwk3wLJ7cbnVUH5gcHsc7kjexXR0wTiOiqApf4HpluPasKqX2d0biZ CiZse0KDGIT22zvfKGG02pv2SYoc87hMmIzk0M2HMHXnWUqeMysT2l8902Uw6X2S4l /YukcNQY7FqFg== Date: Thu, 5 Jun 2025 08:47:31 -0500 From: Rob Herring To: Amit Kumar Mahapatra Cc: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, krzk+dt@kernel.org, conor+dt@kernel.org, linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, git@amd.com, amitrkcian2002@gmail.com Subject: Re: [PATCH v13 1/3] dt-bindings: mtd: Describe MTD partitions concatenation Message-ID: <20250605134731.GA2439158-robh@kernel.org> References: <20250603194209.1341374-1-amit.kumar-mahapatra@amd.com> <20250603194209.1341374-2-amit.kumar-mahapatra@amd.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250603194209.1341374-2-amit.kumar-mahapatra@amd.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250605_064734_249845_D4CA9FB5 X-CRM114-Status: GOOD ( 23.36 ) 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 Wed, Jun 04, 2025 at 01:12:07AM +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 | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml > index 80d0452a2a33..2ef4bde02cd9 100644 > --- a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml > +++ b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml > @@ -57,6 +57,13 @@ properties: > user space from > type: boolean > > + part-concat-next: > + description: List of phandles to MTD partitions that need be concatenated > + with the current partition. > + $ref: /schemas/types.yaml#/definitions/phandle-array > + minItems: 1 > + maxItems: 16 Add: items: maxItems: 1 Because phandle-array is really a matrix. > + > align: > $ref: /schemas/types.yaml#/definitions/uint32 > minimum: 2 > @@ -138,4 +145,15 @@ examples: > reg = <0x200000 0x100000>; > align = <0x4000>; > }; > + > + part0: partition@400000 { > + part-concat-next = <&part1>; > + label = "part0_0"; > + reg = <0x400000 0x100000>; > + }; > + > + part1: partition@800000 { > + label = "part0_1"; > + reg = <0x800000 0x800000>; > + }; > }; > -- > 2.34.1 > ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/