From patchwork Mon May 23 08:59:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen-Yu Tsai X-Patchwork-Id: 12858620 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57C62C433F5 for ; Mon, 23 May 2022 09:00:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232428AbiEWI74 (ORCPT ); Mon, 23 May 2022 04:59:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232398AbiEWI7v (ORCPT ); Mon, 23 May 2022 04:59:51 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86BEA40A14 for ; Mon, 23 May 2022 01:59:49 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id l7-20020a17090aaa8700b001dd1a5b9965so13081296pjq.2 for ; Mon, 23 May 2022 01:59:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RQjXK1tyA9xOYFhndd4nNr3xd4VXsIavQtRl5jsGh4c=; b=meNdqL84O1gmdVv6NUiIDJn815273OPePWQVlLCtG6TSyOYKE4v2G4PfxBLToFL8pO nUY0VM4BReYj05yWLnF2LyruQWkhcyhZ+XwNXzJeHEKBIZLPeU59T/CuMl7NZixuFi09 KXxlHmNQ/PJrF206symEyu+7Zq97H8GYXkS+k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RQjXK1tyA9xOYFhndd4nNr3xd4VXsIavQtRl5jsGh4c=; b=NptuokLzi3/bCHo2FnPmLbQp/JEsjTcP9ZFWQxO5jpWmDW609WY1SPLMUk0jT5/Uw1 9N85kEtGG5JQVFdco1wgBvKhd4TAfUEtDlkCO7csQBChbH7cfLivwT6PBvTm7PDw7ihB k+P4TXWz7FwV3MQrCEuEqUsr31bZV5bjsYX9yGS+VLjgjxJpeJw32ALKf0/sc2ytK77t fv1l9hpfiTh1x6zaHCxoWTm8K5NidiFsDoJIhfVxHqattGASgWN1UFQFTsXSXSFGs3UY 4bsS6omqKcoZp+z2VpxkL2V6mWy2ONiy8LJhV3wnE5RHYLaWA2n8xaDOAgZa9o5fzeKA cyEQ== X-Gm-Message-State: AOAM531qe9OQGhtsQp6/d7Yur1UTIlNb5u4tv/gP3pp5dWLR7mNmlx1Z QQ9X5GgtOCMiDMsZMVz/7iTRzw== X-Google-Smtp-Source: ABdhPJw7GzZaO7+1ExzM7fCYO6HG981ADv0zp7IOz83yeRMp6UwL1C+HSBrvI/3v7TVTfgTNPEgxRw== X-Received: by 2002:a17:90b:4a90:b0:1df:e3af:c6ad with SMTP id lp16-20020a17090b4a9000b001dfe3afc6admr21190655pjb.41.1653296388958; Mon, 23 May 2022 01:59:48 -0700 (PDT) Received: from wenstp920.tpe.corp.google.com ([2401:fa00:1:10:1b8:7eae:9793:ff95]) by smtp.gmail.com with ESMTPSA id e11-20020a170902cf4b00b0015e8d4eb22csm4524719plg.118.2022.05.23.01.59.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 May 2022 01:59:48 -0700 (PDT) From: Chen-Yu Tsai To: Michael Turquette , Stephen Boyd , Matthias Brugger Cc: Chen-Yu Tsai , Rob Herring , Krzysztof Kozlowski , Chun-Jie Chen , Miles Chen , AngeloGioacchino Del Regno , linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/4] clk: mediatek: mt8183: Add clk mux notifier for MFG mux Date: Mon, 23 May 2022 16:59:23 +0800 Message-Id: <20220523085923.1430470-5-wenst@chromium.org> X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog In-Reply-To: <20220523085923.1430470-1-wenst@chromium.org> References: <20220523085923.1430470-1-wenst@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org When the MFG PLL clock, which is upstream of the MFG clock, is changed, the downstream clock and consumers need to be switched away from the PLL over to a stable clock to avoid glitches. This is done through the use of the newly added clk mux notifier. The notifier is set on the mux itself instead of the upstream PLL, but in practice this works, as the rate change notifitcations are propogated throughout the sub-tree hanging off the PLL. Just before rate changes, the MFG mux is temporarily and transparently switched to the 26 MHz main crystal. After the rate change, the mux is switched back. Signed-off-by: Chen-Yu Tsai Reviewed-by: AngeloGioacchino Del Regno --- Changes since v1; - Moved clk notifier registration into separate function - Fixed comment style drivers/clk/mediatek/clk-mt8183.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/clk/mediatek/clk-mt8183.c b/drivers/clk/mediatek/clk-mt8183.c index b5c17988c337..d66acf2e5e19 100644 --- a/drivers/clk/mediatek/clk-mt8183.c +++ b/drivers/clk/mediatek/clk-mt8183.c @@ -1188,10 +1188,33 @@ static void clk_mt8183_top_init_early(struct device_node *node) CLK_OF_DECLARE_DRIVER(mt8183_topckgen, "mediatek,mt8183-topckgen", clk_mt8183_top_init_early); +/* Register mux notifier for MFG mux */ +static int clk_mt8183_reg_mfg_mux_notifier(struct device *dev, struct clk *clk) +{ + struct mtk_mux_nb *mfg_mux_nb; + int i; + + mfg_mux_nb = devm_kzalloc(dev, sizeof(*mfg_mux_nb), GFP_KERNEL); + if (!mfg_mux_nb) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(top_muxes); i++) + if (top_muxes[i].id == CLK_TOP_MUX_MFG) + break; + if (i == ARRAY_SIZE(top_muxes)) + return -EINVAL; + + mfg_mux_nb->mux = &top_muxes[i]; + mfg_mux_nb->bypass_index = 0; /* Bypass to 26M crystal */ + + return devm_mtk_clk_mux_notifier_register(dev, clk, mfg_mux_nb); +} + static int clk_mt8183_top_probe(struct platform_device *pdev) { void __iomem *base; struct device_node *node = pdev->dev.of_node; + int ret; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) @@ -1217,6 +1240,11 @@ static int clk_mt8183_top_probe(struct platform_device *pdev) mtk_clk_register_gates(node, top_clks, ARRAY_SIZE(top_clks), top_clk_data); + ret = clk_mt8183_reg_mfg_mux_notifier(&pdev->dev, + top_clk_data->hws[CLK_TOP_MUX_MFG]->clk); + if (ret) + return ret; + return of_clk_add_hw_provider(node, of_clk_hw_onecell_get, top_clk_data); }