From patchwork Fri Apr 5 00:14:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sowjanya Komatineni X-Patchwork-Id: 10886697 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14BB01708 for ; Fri, 5 Apr 2019 00:15:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00FE928958 for ; Fri, 5 Apr 2019 00:15:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E8F5728AEF; Fri, 5 Apr 2019 00:15:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8C88628958 for ; Fri, 5 Apr 2019 00:15:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730788AbfDEAOk (ORCPT ); Thu, 4 Apr 2019 20:14:40 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:11333 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730762AbfDEAOi (ORCPT ); Thu, 4 Apr 2019 20:14:38 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 04 Apr 2019 17:14:35 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 04 Apr 2019 17:14:37 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 04 Apr 2019 17:14:37 -0700 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL104.nvidia.com (172.18.146.11) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 5 Apr 2019 00:14:37 +0000 Received: from hqnvemgw02.nvidia.com (172.16.227.111) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Fri, 5 Apr 2019 00:14:37 +0000 Received: from skomatineni-linux.nvidia.com (Not Verified[10.110.103.48]) by hqnvemgw02.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Thu, 04 Apr 2019 17:14:36 -0700 From: Sowjanya Komatineni To: , , , , , , , CC: , , , , Subject: [PATCH V2 19/20] DT bindings: spi: document tx/rx clock delay properties Date: Thu, 4 Apr 2019 17:14:18 -0700 Message-ID: <1554423259-26056-19-git-send-email-skomatineni@nvidia.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1554423259-26056-1-git-send-email-skomatineni@nvidia.com> References: <1554423259-26056-1-git-send-email-skomatineni@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1554423275; bh=UI55pKb+sdPb0XZNgJdTj04yVil0AOFyMJLcyBa3hBg=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=A3nvBv7LMSJxcYh/FOSRrSZZJWA3k47qR+eWNoKbHsA+9WetpafyUwv9ppkNWrppz fulVDOeprn9gD1m/ETLiyFYU4oYh47kb8YrAPPOvECs9QPtY94sh7sLsuP1ZXV9gWy I8frshjitX+8gK4D3SX6qXpoCmB2LDPcHGS3pHUZ6IjyJf4oXB/i+wy5+iijCw9Yc1 z3qdVZls4rRuFbWLRI48WWFOBG3Y+u7sU1k8JprRxkGguOe2qE8BQdXP6oZjd3tSl5 XKeElRAKCxraqTyo+qKuf383lD9f2DMqc1ZS3iLaZxtHCkrw1lavglKUeZtFnF480R BSv24yp3C8XJA== Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Tegra SPI controller has TX and RX trimmers to tuning the delay of SPI master clock with respect to the data. TX and RX tap values are based on the platform validation across the PVT and the trimmer values vary based on the trace lengths to the corresponding SPI devices. Signed-off-by: Sowjanya Komatineni --- .../devicetree/bindings/spi/nvidia,tegra114-spi.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt index 9ba7c5a273b4..db8e0d71c5bc 100644 --- a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt +++ b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt @@ -23,6 +23,18 @@ Required properties: Recommended properties: - spi-max-frequency: Definition as per Documentation/devicetree/bindings/spi/spi-bus.txt +Optional properties: +- nvidia,tx-clk-tap-delay: Delays the clock going out to the external device + with this tap value. This property is used to tune the outgoing data from + Tegra SPI master with respect to outgoing Tegra SPI master clock. + Tap values vary based on the platform design trace lengths from Tegra SPI + to corresponding slave devices. Valid tap values are from 0 thru 63. +- nvidia,rx-clk-tap-delay: Delays the clock coming in from the external device + with this tap value. This property is used to adjust the Tegra SPI master + clock with respect to the data from the SPI slave device. + Tap values vary based on the platform design trace lengths from Tegra SPI + to corresponding slave devices. Valid tap values are from 0 thru 63. + Example: spi@7000d600 { @@ -38,4 +50,12 @@ spi@7000d600 { reset-names = "spi"; dmas = <&apbdma 16>, <&apbdma 16>; dma-names = "rx", "tx"; + @ { + ... + ... + nvidia,rx-clk-tap-delay = <0>; + nvidia,tx-clk-tap-delay = <16>; + ... + }; + };