From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9541CC433EF for ; Mon, 18 Jun 2018 07:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42EC020874 for ; Mon, 18 Jun 2018 07:22:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42EC020874 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755202AbeFRHWr (ORCPT ); Mon, 18 Jun 2018 03:22:47 -0400 Received: from lithops.sigma-star.at ([195.201.40.130]:42060 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754973AbeFRHWq (ORCPT ); Mon, 18 Jun 2018 03:22:46 -0400 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id DEFCB608D738; Mon, 18 Jun 2018 09:22:44 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id YKte6Gqq596F; Mon, 18 Jun 2018 09:22:44 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 95A0660A3578; Mon, 18 Jun 2018 09:22:44 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id IksMrOumVY2g; Mon, 18 Jun 2018 09:22:44 +0200 (CEST) Received: from blindfold.localnet (unknown [82.150.214.1]) by lithops.sigma-star.at (Postfix) with ESMTPSA id 7419B60A3568; Mon, 18 Jun 2018 09:22:44 +0200 (CEST) From: Richard Weinberger To: Masahiro Yamada Cc: linux-mtd@lists.infradead.org, Boris Brezillon , Rob Herring , linux-kbuild@vger.kernel.org, Miquel Raynal , linux-kernel@vger.kernel.org, Marek Vasut , Brian Norris , David Woodhouse Subject: Re: [PATCH v3 3/3] mtd: rawnand: denali: optimize timing parameters for data interface Date: Mon, 18 Jun 2018 09:22:44 +0200 Message-ID: <34780659.LX1KsSZy9L@blindfold> In-Reply-To: <1529025532-22087-4-git-send-email-yamada.masahiro@socionext.com> References: <1529025532-22087-1-git-send-email-yamada.masahiro@socionext.com> <1529025532-22087-4-git-send-email-yamada.masahiro@socionext.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, 15. Juni 2018, 03:18:52 CEST schrieb Masahiro Yamada: > This commit improves the ->setup_data_interface() hook. > > The denali_setup_data_interface() needs the frequency of clk_x > and the ratio of clk_x / clk. > > The latter is currently hardcoded in the driver, like this: > > #define DENALI_CLK_X_MULT 6 > > The IP datasheet requires that clk_x / clk be 4, 5, or 6. I just > chose 6 because it is the most defensive value, but it is not optimal. > By getting the clock rate of both "clk" and "clk_x", the driver can > compute the timing values more precisely. What datasheet do you have, is it public? Mine clearly states that the factor is 4. "The frequency of nand_x_clk is four times the frequency of nand_clk." > To not break the existing platforms, the fallback value, 50 MHz is > provided. It is true for all upstreamed platforms. > > Signed-off-by: Masahiro Yamada Reviewed-by: Richard Weinberger Thanks, //richard