From patchwork Wed Jan 26 11:26:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 1584422 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=3ysrVTOx; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4JkM5p6K6Dz9t6g for ; Wed, 26 Jan 2022 22:32:46 +1100 (AEDT) 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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CBdPMCEkxPL1tgrg/vfZZIOjDmkvZbMHyI6cGMWu/oM=; b=3ysrVTOxQT1Qle AKM4hcKUi5rUwoAFTKCvaeBoHoQcL4yONVIAV8MRAeEzVv2RT6FcDhuik9w7OtgyncLg19fhIEEXL 5a1Tnb5rGH1MPcDamw26UqYGupmj+38OPWK/EDG47y0itKGRGuWnGiBMU8ewWVecVwLbWu+/HteO9 GjPTU4OaVrX3MI3pOkXSZpWvHrR82VGonJdyvo/8w5kVMnvFPG7hEIHIEvK8o/qvAyi2iZKaOK6Cx /sqScTg8TedFRPr2efiZSTF8cHoahxIR9sJOSZGSB9Ta+S35hvqJq6Jq1pFcNUbXAF6MSBEA8VfE3 mc3UWOFkppwvWrTs/i3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCgX0-00BUga-B9; Wed, 26 Jan 2022 11:32:06 +0000 Received: from relay3-d.mail.gandi.net ([217.70.183.195]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCgRL-00BTKm-Dt for linux-mtd@lists.infradead.org; Wed, 26 Jan 2022 11:26:16 +0000 Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 8A6E46000E; Wed, 26 Jan 2022 11:26:12 +0000 (UTC) From: Miquel Raynal To: Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , Pratyush Yadav , Michael Walle , Cc: Rob Herring , , Michal Simek , Thomas Petazzoni , Mark Brown , , Miquel Raynal Subject: [PATCH v6 2/3] spi: dt-bindings: Describe stacked/parallel memories modes Date: Wed, 26 Jan 2022 12:26:06 +0100 Message-Id: <20220126112608.955728-3-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220126112608.955728-1-miquel.raynal@bootlin.com> References: <20220126112608.955728-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_032615_651309_EA3F56F6 X-CRM114-Status: GOOD ( 11.78 ) X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. 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Content preview: Describe two new memories modes: - A stacked mode when the bus is common but the address space extended with an additinals wires. - A parallel mode with parallel busses accessing parallel flashes wher [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [217.70.183.195 listed in wl.mailspike.net] -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.183.195 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders 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: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Describe two new memories modes: - A stacked mode when the bus is common but the address space extended with an additinals wires. - A parallel mode with parallel busses accessing parallel flashes where the data is spread. Signed-off-by: Miquel Raynal Acked-by: Pratyush Yadav Reviewed-by: Rob Herring --- .../bindings/spi/spi-peripheral-props.yaml | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml index 5dd209206e88..fedb7ae98ff6 100644 --- a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml @@ -82,6 +82,31 @@ properties: description: Delay, in microseconds, after a write transfer. + stacked-memories: + description: Several SPI memories can be wired in stacked mode. + This basically means that either a device features several chip + selects, or that different devices must be seen as a single + bigger chip. This basically doubles (or more) the total address + space with only a single additional wire, while still needing + to repeat the commands when crossing a chip boundary. The size of + each chip should be provided as members of the array. + $ref: /schemas/types.yaml#/definitions/uint64-array + minItems: 2 + maxItems: 4 + + parallel-memories: + description: Several SPI memories can be wired in parallel mode. + The devices are physically on a different buses but will always + act synchronously as each data word is spread across the + different memories (eg. even bits are stored in one memory, odd + bits in the other). This basically doubles the address space and + the throughput while greatly complexifying the wiring because as + many busses as devices must be wired. The size of each chip should + be provided as members of the array. + $ref: /schemas/types.yaml#/definitions/uint64-array + minItems: 2 + maxItems: 4 + # The controller specific properties go here. allOf: - $ref: cdns,qspi-nor-peripheral-props.yaml#