From patchwork Thu Jul 16 15:27:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyrille Pitchen X-Patchwork-Id: 6808231 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AE2A19F2E8 for ; Thu, 16 Jul 2015 15:30:04 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CADFB2065A for ; Thu, 16 Jul 2015 15:30:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EB61E205E6 for ; Thu, 16 Jul 2015 15:30:02 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZFl51-0000pZ-70; Thu, 16 Jul 2015 15:28:11 +0000 Received: from eusmtp01.atmel.com ([212.144.249.243]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZFl4o-0000cZ-0H; Thu, 16 Jul 2015 15:27:58 +0000 Received: from tenerife.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.31) with Microsoft SMTP Server id 14.3.235.1; Thu, 16 Jul 2015 17:27:36 +0200 From: Cyrille Pitchen To: , , , , , , , , , , Subject: [PATCH 1/7] Documentation: mtd: add a DT property to set the number of dummy cycles Date: Thu, 16 Jul 2015 17:27:48 +0200 Message-ID: <0eacf9dac878768b4cf915f926c628d9e65499df.1437059658.git.cyrille.pitchen@atmel.com> X-Mailer: git-send-email 1.8.2.2 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150716_082758_241255_0DCE9142 X-CRM114-Status: UNSURE ( 8.62 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -5.5 (-----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, linux-kernel@vger.kernel.org, robh+dt@kernel.org, linux-mtd@lists.infradead.org, galak@codeaurora.org, Cyrille Pitchen , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Depending on the SPI clock frequency, the Fast Read op code and the Single/Dual Data Rate mode, the number of dummy cycles can be tuned to improve transfer speed. The actual number of dummy cycles is specific for each memory model and is provided by the manufacturer thanks to the memory datasheet. Signed-off-by: Cyrille Pitchen --- Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt index 2bee68103b01..4387567d8024 100644 --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt @@ -19,6 +19,11 @@ Optional properties: all chips and support for it can not be detected at runtime. Refer to your chips' datasheet to check if this is supported by your chip. +- m25p,num-dummy-cycles : Set the number of dummy cycles for Fast Read commands. + Depending on the manufacturer additional dedicated + commands are sent to the flash memory so the + controller and the memory can agree on the number of + dummy cycles to use. Example: @@ -29,4 +34,5 @@ Example: reg = <0>; spi-max-frequency = <40000000>; m25p,fast-read; + m25p,num-dummy-cycles = <8>; };