Message ID | 20221117105249.115649-7-tudor.ambarus@microchip.com |
---|---|
State | Superseded |
Delegated to: | Ambarus Tudor |
Headers | show
Return-Path: <linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org> X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=<UNKNOWN>) Authentication-Results: legolas.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=p0hXQ5cw; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=microchip.com header.i=@microchip.com header.a=rsa-sha256 header.s=mchp header.b=z1cYFK+O; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NCcTl12Hjz23mR for <incoming@patchwork.ozlabs.org>; Thu, 17 Nov 2022 22:03:23 +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=XvnfTF7zuPMdlIpUZYddttCXhV1GT+ln4IR6OttWs8k=; b=p0hXQ5cwRLi4PB ERIUwzTySAj14t6hrfGtwStm6C83Wl6dWfYp46qgvhY1SJBRvRjV3vVilhxj6f+9CYnK0hVQjbQ7N n6spRQDGuDRLuVgBKdC0uJ+6OeWNUPVchKnZuoVYGFPpdm+FUMOz3swkwWWOmXGRpQWiWMEnn+/qG JCPvZXeBN2zMP/2fzjVdtA89IzgmnRIHhjmxfpTsekIR7KLxbSSLx6FllxWx5ma2YxrZQFlUTZGsa arZM91AQ61LjhFQSmLeI2pJ8f7YJT3drZdY9Q/QpFzLxn/Zay6Zc3k6ChQl7bI4IfHjAdFMGmAqqr 4gyTgrU+x2X7Mxleq80g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovcfF-00Cte6-4u; Thu, 17 Nov 2022 11:02:37 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovcWD-00CoMz-H2; Thu, 17 Nov 2022 10:53:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1668682398; x=1700218398; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=H6jfv/98Y/BHItdiM3LYtojQb8Xu3XwDeExUAi0R+zs=; b=z1cYFK+OLBZGxMMogW4KNZ2mZnOIBPB5I7ZKsfP0zBTAN4G8F0vZ2Qp6 27tt07qT2VKT4jd5iI7td9BzTtmwf5A7deukzgAZG1RudHILh/NQjGdvW THu9UVdrBYkVo8zkQZ2w17W8yK2PQumzXpb6vlfSFJL4UBjCh2v/bJEl3 qzBzn7ucOU7icbNNncN/4soQomq/qikfkeTbW8r/OW5QykpxtJcFhUxlj YQCHoEQyRCyVeULAGLRESxPhfSqPTUxbr02p2Pgw5SYdnqXvN+bRkodax IBAO897VxOHNiZwTe4eMFX4GMV+D+Hj5v32ju+9Mhg0TGDf5quD4+WAHy w==; X-IronPort-AV: E=Sophos;i="5.96,171,1665471600"; d="scan'208";a="183965650" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 17 Nov 2022 03:53:15 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Thu, 17 Nov 2022 03:53:11 -0700 Received: from ROB-ULT-M18064N.mchp-main.com (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server id 15.1.2507.12 via Frontend Transport; Thu, 17 Nov 2022 03:53:09 -0700 From: Tudor Ambarus <tudor.ambarus@microchip.com> To: <broonie@kernel.org>, <robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>, <nicolas.ferre@microchip.com>, <alexandre.belloni@bootlin.com>, <claudiu.beznea@microchip.com> CC: <linux-spi@vger.kernel.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-mtd@lists.infradead.org>, Tudor Ambarus <tudor.ambarus@microchip.com> Subject: [PATCH 6/8] ARM: dts: at91-sama5d27_som1: Set sst26vf064b SPI NOR flash at its maximum frequency Date: Thu, 17 Nov 2022 12:52:47 +0200 Message-ID: <20221117105249.115649-7-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221117105249.115649-1-tudor.ambarus@microchip.com> References: <20221117105249.115649-1-tudor.ambarus@microchip.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221117_025317_751835_B56879C0 X-CRM114-Status: GOOD ( 10.02 ) X-Spam-Score: -2.7 (--) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: sama5d27-som1 populates an sst26vf064b SPI NOR flash. Its maximum operating frequency for 2.7-3.6V is 104 MHz. As the flash is operated at 3.3V, increase its maximum supported frequency to 104MHz. The [...] Content analysis details: (-2.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [68.232.154.123 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.2 DKIMWL_WL_HIGH DKIMwl.org - High trust sender X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org> List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>, <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe> List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/> List-Post: <mailto:linux-mtd@lists.infradead.org> List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help> List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>, <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" <linux-mtd-bounces@lists.infradead.org> Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org |
Series |
spi: Introduce spi-cs-setup-ns dt property
|
expand
|
diff --git a/arch/arm/boot/dts/at91-sama5d27_som1.dtsi b/arch/arm/boot/dts/at91-sama5d27_som1.dtsi index 8aa9e8dea337..243f09f40761 100644 --- a/arch/arm/boot/dts/at91-sama5d27_som1.dtsi +++ b/arch/arm/boot/dts/at91-sama5d27_som1.dtsi @@ -43,7 +43,8 @@ flash@0 { #size-cells = <1>; compatible = "jedec,spi-nor"; reg = <0>; - spi-max-frequency = <80000000>; + spi-max-frequency = <104000000>; + spi-cs-setup-ns = /bits/ 16 <7>; spi-tx-bus-width = <4>; spi-rx-bus-width = <4>; m25p,fast-read;
sama5d27-som1 populates an sst26vf064b SPI NOR flash. Its maximum operating frequency for 2.7-3.6V is 104 MHz. As the flash is operated at 3.3V, increase its maximum supported frequency to 104MHz. The increasing of the spi-max-frequency value requires the setting of the "CE# Not Active Hold Time", thus set the spi-cs-setup-ns to a value of 7. The sst26vf064b datasheet specifies just a minimum value for the "CE# Not Active Hold Time" and it advertises it to 5 ns. There's no maximum time specified. I determined experimentally that 5 ns for the spi-cs-setup-ns is not enough when the flash is operated close to its maximum frequency and tests showed that 7 ns is just fine, so set the spi-cs-setup-ns dt property to 7. With the increase of frequency the reads are now faster with ~37%. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> --- arch/arm/boot/dts/at91-sama5d27_som1.dtsi | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)