From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751392AbdJCFWO (ORCPT ); Tue, 3 Oct 2017 01:22:14 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:12665 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbdJCFWK (ORCPT ); Tue, 3 Oct 2017 01:22:10 -0400 From: Vignesh R To: Marek Vasut , Cyrille Pitchen CC: David Woodhouse , Brian Norris , Boris Brezillon , Rob Herring , , , , Vignesh R , linux-arm-kernel Subject: [PATCH v4 3/6] mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back circuit Date: Tue, 3 Oct 2017 10:49:22 +0530 Message-ID: <20171003051925.8821-4-vigneshr@ti.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171003051925.8821-1-vigneshr@ti.com> References: <20171003051925.8821-1-vigneshr@ti.com> MIME-Version: 1.0 Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cadence QSPI IP has a adapted loop-back circuit which can be enabled by setting BYPASS field to 0 in READCAPTURE register. It enables use of QSPI return clock to latch the data rather than the internal QSPI reference clock. For high speed operations, adapted loop-back circuit using QSPI return clock helps to increase data valid window. Add DT parameter cdns,rclk-en to help enable adapted loop-back circuit for boards which do have QSPI return clock provided. Update binding documentation for the same. Signed-off-by: Vignesh R Acked-by: Rob Herring --- Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt index 7dbe3bd9ac56..bb2075df9b38 100644 --- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt @@ -16,6 +16,9 @@ Required properties: Optional properties: - cdns,is-decoded-cs : Flag to indicate whether decoder is used or not. +- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch + the read data rather than the QSPI clock. Make sure that QSPI return + clock is populated on the board before using this property. Optional subnodes: Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional -- 2.14.1