From patchwork Mon Feb 26 09:53:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 10241863 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 8AD42602DC for ; Mon, 26 Feb 2018 09:55:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C74A29ED2 for ; Mon, 26 Feb 2018 09:55:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 60D8929ED5; Mon, 26 Feb 2018 09:55:40 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable 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 E76D229ED2 for ; Mon, 26 Feb 2018 09:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752677AbeBZJzX (ORCPT ); Mon, 26 Feb 2018 04:55:23 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:47524 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752608AbeBZJzO (ORCPT ); Mon, 26 Feb 2018 04:55:14 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id AB41560FF7; Mon, 26 Feb 2018 09:55:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1519638913; bh=6LucRXrRc42tWzobqIQg+Ers07IO/DJr0pnLHkrYqaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QBJVODrZ6VEy2cjns3Ky/Zm+oKxu2r/UUYB6+/63a6p2f/kGBi4/nmQlSMcP7fXxt 4kqgbgs0Xq0dk/5nrT98bqKe//qFcvOvycRg7hEp54Mq9KNTcUAPF6EZcaTmqiTZIl pEeWzQcWczqnLn3RuCXnTHE1G1TLjlIVbat+JcPY= Received: from srichara-linux.qualcomm.com (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 5F58D60F6C; Mon, 26 Feb 2018 09:55:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1519638905; bh=6LucRXrRc42tWzobqIQg+Ers07IO/DJr0pnLHkrYqaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iUTpWjbYgvSq7kn29dn6UBwp+laEjkCSZIzWWISaY0c7tMEI8JcCo4jmCZClWL8pr tTUAVvs/QAUS7QVFvlj/v75dZLFljjBy1mAqIgoj7HkZAnfwHjdqG6GT8/n0784NsH NEvyAiqCtB2fwA2eAaXzeb3I9egDMTralzfV3Qa4= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 5F58D60F6C Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sricharan@codeaurora.org From: Sricharan R To: viresh.kumar@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, mturquette@baylibre.com, sboyd@codeaurora.org, linux@armlinux.org.uk, andy.gross@linaro.org, david.brown@linaro.org, rjw@rjwysocki.net, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-pm@vger.kernel.org, robh@kernel.org Cc: sricharan@codeaurora.org Subject: [PATCH v7 13/15] clk: qcom: Add safe switch hook for krait mux clocks Date: Mon, 26 Feb 2018 15:23:29 +0530 Message-Id: <1519638811-17269-14-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1519638811-17269-1-git-send-email-sricharan@codeaurora.org> References: <1519638811-17269-1-git-send-email-sricharan@codeaurora.org> Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When the Hfplls are reprogrammed during the rate change, the primary muxes which are sourced from the same hfpll for higher frequencies, needs to be switched to the 'safe secondary mux' as the parent for that small window. This is done by registering a clk notifier for the muxes and switching to the safe parent in the PRE_RATE_CHANGE notifier and back to the original parent in the POST_RATE_CHANGE notifier. Signed-off-by: Sricharan R --- drivers/clk/qcom/clk-krait.c | 2 ++ drivers/clk/qcom/clk-krait.h | 3 +++ drivers/clk/qcom/krait-cc.c | 56 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+) diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c index 2e41767..ac2e020 100644 --- a/drivers/clk/qcom/clk-krait.c +++ b/drivers/clk/qcom/clk-krait.c @@ -50,6 +50,8 @@ static int krait_mux_set_parent(struct clk_hw *hw, u8 index) if (__clk_is_enabled(hw->clk)) __krait_mux_set_sel(mux, sel); + mux->reparent = true; + return 0; } diff --git a/drivers/clk/qcom/clk-krait.h b/drivers/clk/qcom/clk-krait.h index 71890bc..986f356 100644 --- a/drivers/clk/qcom/clk-krait.h +++ b/drivers/clk/qcom/clk-krait.h @@ -13,6 +13,9 @@ struct krait_mux_clk { u32 shift; u32 en_mask; bool lpl; + u8 safe_sel; + u8 old_index; + bool reparent; struct clk_hw hw; struct notifier_block clk_nb; diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c index 7c9dfb0..4d4b657 100644 --- a/drivers/clk/qcom/krait-cc.c +++ b/drivers/clk/qcom/krait-cc.c @@ -26,6 +26,49 @@ 0, }; +/* + * Notifier function for switching the muxes to safe parent + * while the hfpll is getting reprogrammed. + */ +static int krait_notifier_cb(struct notifier_block *nb, + unsigned long event, + void *data) +{ + int ret = 0; + struct krait_mux_clk *mux = container_of(nb, struct krait_mux_clk, + clk_nb); + /* Switch to safe parent */ + if (event == PRE_RATE_CHANGE) { + mux->old_index = krait_mux_clk_ops.get_parent(&mux->hw); + ret = krait_mux_clk_ops.set_parent(&mux->hw, mux->safe_sel); + mux->reparent = false; + /* + * By the time POST_RATE_CHANGE notifier is called, + * clk framework itself would have changed the parent for the new rate. + * Only otherwise, put back to the old parent. + */ + } else if (event == POST_RATE_CHANGE) { + if (!mux->reparent) + ret = krait_mux_clk_ops.set_parent(&mux->hw, + mux->old_index); + } + + return notifier_from_errno(ret); +} + +static int krait_notifier_register(struct device *dev, struct clk *clk, + struct krait_mux_clk *mux) +{ + int ret = 0; + + mux->clk_nb.notifier_call = krait_notifier_cb; + ret = clk_notifier_register(clk, &mux->clk_nb); + if (ret) + dev_err(dev, "failed to register clock notifier: %d\n", ret); + + return ret; +} + static int krait_add_div(struct device *dev, int id, const char *s, unsigned int offset) { @@ -70,6 +113,7 @@ krait_add_sec_mux(struct device *dev, int id, const char *s, unsigned int offset, bool unique_aux) { + int ret; struct krait_mux_clk *mux; static const char *sec_mux_list[] = { "acpu_aux", @@ -93,6 +137,7 @@ mux->shift = 2; mux->parent_map = sec_mux_map; mux->hw.init = &init; + mux->safe_sel = 0; init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s); if (!init.name) @@ -108,6 +153,11 @@ clk = devm_clk_register(dev, &mux->hw); + ret = krait_notifier_register(dev, clk, mux); + if (ret) + goto unique_aux; + +unique_aux: if (unique_aux) kfree(sec_mux_list[0]); err_aux: @@ -119,6 +169,7 @@ krait_add_pri_mux(struct device *dev, int id, const char *s, unsigned int offset) { + int ret; struct krait_mux_clk *mux; const char *p_names[3]; struct clk_init_data init = { @@ -139,6 +190,7 @@ mux->lpl = id >= 0; mux->parent_map = pri_mux_map; mux->hw.init = &init; + mux->safe_sel = 2; init.name = kasprintf(GFP_KERNEL, "krait%s_pri_mux", s); if (!init.name) @@ -164,6 +216,10 @@ clk = devm_clk_register(dev, &mux->hw); + ret = krait_notifier_register(dev, clk, mux); + if (ret) + goto err_p3; +err_p3: kfree(p_names[2]); err_p2: kfree(p_names[1]);