From patchwork Tue Feb 6 04:08:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 10202247 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 E073860247 for ; Tue, 6 Feb 2018 04:11:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D109028928 for ; Tue, 6 Feb 2018 04:11:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C5B2B28A31; Tue, 6 Feb 2018 04:11:32 +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 2BF3128928 for ; Tue, 6 Feb 2018 04:11:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752800AbeBFELa (ORCPT ); Mon, 5 Feb 2018 23:11:30 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:53170 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752532AbeBFEKk (ORCPT ); Mon, 5 Feb 2018 23:10:40 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id EFED560A26; Tue, 6 Feb 2018 04:10:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1517890239; bh=6LucRXrRc42tWzobqIQg+Ers07IO/DJr0pnLHkrYqaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JXB2ZQlYqnKSs6YMVIHvThCeOfF3cHKMVvbtQInT6QF3ymcZ37ZDj41XyRKcqJBcW +BqH9KY1UsbJ1I6udr7trhMOnfOPwUHg9f6vAs+WgSD9YgsY7KJxTgNdZkR7upTFWL 3ifjubL3riZM1J7SZUnQrMf13dCx0hUfvw+a3k7g= 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 E9B1660FF2; Tue, 6 Feb 2018 04:10:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1517890222; bh=6LucRXrRc42tWzobqIQg+Ers07IO/DJr0pnLHkrYqaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d1YkyS/6UTzQRP8BjjWdEOBvmqn2ny263XtsmSoZywRpKoBrVPtqF3vBF1izKn8As atsRSsOvKh+qXNH86TiyX5CLpY0in////WloiS/cyWdMbNeCvwz0zQQ4zlo3+j3Ua+ kYhCjgbCCZGmt4+Z6hG8DNnwmB9nvkVAMOedptQw= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E9B1660FF2 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 v6 13/15] clk: qcom: Add safe switch hook for krait mux clocks Date: Tue, 6 Feb 2018 09:38:26 +0530 Message-Id: <1517890108-8140-14-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1517890108-8140-1-git-send-email-sricharan@codeaurora.org> References: <1517890108-8140-1-git-send-email-sricharan@codeaurora.org> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@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]);