From patchwork Tue Feb 7 21:33:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiner Kallweit X-Patchwork-Id: 9561249 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 152026047A for ; Tue, 7 Feb 2017 21:44:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07D9F28461 for ; Tue, 7 Feb 2017 21:44:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F05882847B; Tue, 7 Feb 2017 21:44:26 +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=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID 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 744E228475 for ; Tue, 7 Feb 2017 21:44:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932313AbdBGVoZ (ORCPT ); Tue, 7 Feb 2017 16:44:25 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:33852 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176AbdBGVoZ (ORCPT ); Tue, 7 Feb 2017 16:44:25 -0500 Received: by mail-wm0-f65.google.com with SMTP id c85so30743803wmi.1 for ; Tue, 07 Feb 2017 13:44:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:subject:to:cc:message-id:date:user-agent:mime-version :content-transfer-encoding; bh=xfPPIODlHSXqRlcvbI0LKHq7SbQb2uP1shuSl6hWHeI=; b=f9hjO3lij3bptLqdFYJ+GnoVSJyUBHf6oLVa23WZSv7PcelBW5MVQOgNJ7dWPst7IR 9SoWSYKgl3nM7GitYZMVtA28vyeplq8Jz9cuEO+nkYrxzjH1qDe2FcJu30XDR9zEvgZ3 YLUJ+aZJY14MOeNydct9BFfD1o4Mz85TpcX+XEoeOAwLAOROxwKBf1jH79Ka7YcQGkqu sw58oDD/xJB1pyStCDgffCnOpCYBb40HNWt2fFHfJ8P0EAV/vd1h5H7xJOxFgKY2yIwR jhyGLfZtrFSbTyw8PxKrMaJtjasZbk8H7+SW6PdPzxNBnv8lt8Y4Gq+zAnl4S7sRkRcA /xaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:cc:message-id:date:user-agent :mime-version:content-transfer-encoding; bh=xfPPIODlHSXqRlcvbI0LKHq7SbQb2uP1shuSl6hWHeI=; b=ak8HEKYYU5BJiWVDvt09kNEjjR7uN3E1ktrQBs2iJhRzfkJ4ypFOTT25igw2bnuu6h kRfbjoj+MX9qWy5K3fy9NOka+oYJnv0pnXOsx4iQyS8mJuWFKOWkwHV2csNffxhGkq3j BLyr5yQVdpBOOKiQ0cY1Yzxa4EoPLo21wUIGxUaD0zoQI6i3d6BBGNutYTSEGVNXdtmu Tm12o6McJ9EW7FQcP6Qjw9r6pK/5KU9FebaZ/pUkVwp+XyBKpnKDX1EAWi2mrHuLtFKt KrBkVgor3gTbxCrBYtwdqh/GgR4iJBAsZs4UIboAxTTOIAVmDyM28QGBI83FUq4q5Dk3 SnyQ== X-Gm-Message-State: AMke39msJFqdZyII3Ohr+zyy2F5yBT3pV78Rmr+vNxJN4DEAezzxbgSWpcCNLzoYlZGOFQ== X-Received: by 10.28.169.197 with SMTP id s188mr14141024wme.24.1486503372240; Tue, 07 Feb 2017 13:36:12 -0800 (PST) Received: from ?IPv6:2003:c6:ebce:1e00:cd3f:c3c7:98c5:4fec? (p200300C6EBCE1E00CD3FC3C798C54FEC.dip0.t-ipconnect.de. [2003:c6:ebce:1e00:cd3f:c3c7:98c5:4fec]) by smtp.googlemail.com with ESMTPSA id o143sm704086wmd.3.2017.02.07.13.36.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Feb 2017 13:36:11 -0800 (PST) From: Heiner Kallweit Subject: [PATCH v3 1/9] mmc: meson: Assign the minimum clk rate as close to 400KHz as possible To: Ulf Hansson , Kevin Hilman Cc: Carlo Caione , "linux-mmc@vger.kernel.org" , linux-amlogic@lists.infradead.org Message-ID: Date: Tue, 7 Feb 2017 22:33:56 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The current code dealing with calculating mmc->f_min is a bit complicated. Additionally, the attempt to set an initial clock rate should explicitly use a rate between 100KHz to 400 KHz, according the (e)MMC/SD specs, which it doesn't. Fix the problem and clean up the code by using clk_round_rate() to pick the nearest minimum rate to 400KHz (rounded down from 400kHz). Signed-off-by: Ulf Hansson Signed-off-by: Heiner Kallweit --- v3: - remove now unused member mux_parent_rate from struct meson_host - change target min rate from 100kHz to 400kHz because actual min rate on meson is 380kHz. Therefore 100kHz would be rounded down to 0. --- drivers/mmc/host/meson-gx-mmc.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 5eca88bc..ef2ce725 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -132,7 +132,6 @@ struct meson_host { struct clk_mux mux; struct clk *mux_clk; struct clk *mux_parent[MUX_CLK_NUM_PARENTS]; - unsigned long mux_parent_rate[MUX_CLK_NUM_PARENTS]; struct clk_divider cfg_div; struct clk *cfg_div_clk; @@ -240,7 +239,6 @@ static int meson_mmc_clk_init(struct meson_host *host) const char *mux_parent_names[MUX_CLK_NUM_PARENTS]; unsigned int mux_parent_count = 0; const char *clk_div_parents[1]; - unsigned int f_min = UINT_MAX; u32 clk_reg, cfg; /* get the mux parents */ @@ -257,20 +255,10 @@ static int meson_mmc_clk_init(struct meson_host *host) return ret; } - host->mux_parent_rate[i] = clk_get_rate(host->mux_parent[i]); mux_parent_names[i] = __clk_get_name(host->mux_parent[i]); mux_parent_count++; - if (host->mux_parent_rate[i] < f_min) - f_min = host->mux_parent_rate[i]; } - /* cacluate f_min based on input clocks, and max divider value */ - if (f_min != UINT_MAX) - f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); - else - f_min = 4000000; /* default min: 400 MHz */ - host->mmc->f_min = f_min; - /* create the mux */ snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev)); init.name = clk_name; @@ -325,9 +313,13 @@ static int meson_mmc_clk_init(struct meson_host *host) writel(cfg, host->regs + SD_EMMC_CFG); ret = clk_prepare_enable(host->cfg_div_clk); - if (!ret) - ret = meson_mmc_clk_set(host, f_min); + if (ret) + return ret; + + /* Get the nearest minimum clock to 400KHz */ + host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 400000); + ret = meson_mmc_clk_set(host, host->mmc->f_min); if (!ret) clk_disable_unprepare(host->cfg_div_clk);