Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932583AbbHXKOe (ORCPT ); Mon, 24 Aug 2015 06:14:34 -0400 Received: from eusmtp01.atmel.com ([212.144.249.242]:24853 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751422AbbHXKOc (ORCPT ); Mon, 24 Aug 2015 06:14:32 -0400 From: Cyrille Pitchen To: , , , , , , , , , , CC: , , , , , , , , , Cyrille Pitchen Subject: [PATCH linux-next v4 2/5] Documentation: mtd: add a DT property to set the number of dummy cycles Date: Mon, 24 Aug 2015 12:13:57 +0200 Message-ID: <22db2e7d5126fc182eb7e26ada9de390165cb2fc.1440410236.git.cyrille.pitchen@atmel.com> X-Mailer: git-send-email 1.8.2.2 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1756 Lines: 41 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>; }; -- 1.8.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/