From patchwork Tue Jun 21 13:49:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhishek Sahu X-Patchwork-Id: 9190619 X-Patchwork-Delegate: sboyd@codeaurora.org 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 25A1E6089F for ; Tue, 21 Jun 2016 13:51:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 12B1D27FAD for ; Tue, 21 Jun 2016 13:51:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 06E2028174; Tue, 21 Jun 2016 13:51:58 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI 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 1ABF127FAD for ; Tue, 21 Jun 2016 13:51:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751974AbcFUNv1 (ORCPT ); Tue, 21 Jun 2016 09:51:27 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:34636 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751577AbcFUNus (ORCPT ); Tue, 21 Jun 2016 09:50:48 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 7917761263; Tue, 21 Jun 2016 13:50:18 +0000 (UTC) Received: from chewinlnx07.qualcomm.com (unknown [202.46.23.62]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: absahu@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4109E61264; Tue, 21 Jun 2016 13:50:10 +0000 (UTC) From: Abhishek Sahu To: andy.gross@linaro.org, david.brown@linaro.org, sboyd@codeaurora.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk Cc: mturquette@baylibre.com, galak@codeaurora.org, pradeepb@codeaurora.org, mmcclint@codeaurora.org, varada@codeaurora.org, sricharan@codeaurora.org, architt@codeaurora.org, ntelkar@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Abhishek Sahu Subject: [PATCH v2 5/5] clk: qcom: ipq4019: Added the cpu clock frequency change notifier Date: Tue, 21 Jun 2016 19:19:22 +0530 Message-Id: <1466516962-18087-6-git-send-email-absahu@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1466516962-18087-1-git-send-email-absahu@codeaurora.org> References: <1466516962-18087-1-git-send-email-absahu@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 The current driver code gives the crash or gets hang while switching the CPU frequency some time. The APSS CPU Clock divider is not glitch free so it the APPS clock need to be switched for stable clock during the change. This patch adds the frequency change notifier for APSS CPU clock. It changes the parent of this clock to stable PLL FEPLL500 when it gets for PRE_RATE_CHANGE event. This event will be generated before actual clock set operations. The clock set operation will again change its corresponding parent by getting the same from frequency table. Signed-off-by: Abhishek Sahu --- drivers/clk/qcom/gcc-ipq4019.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/clk/qcom/gcc-ipq4019.c b/drivers/clk/qcom/gcc-ipq4019.c index df159c2..3c014f7 100644 --- a/drivers/clk/qcom/gcc-ipq4019.c +++ b/drivers/clk/qcom/gcc-ipq4019.c @@ -1740,9 +1740,34 @@ static const struct of_device_id gcc_ipq4019_match_table[] = { }; MODULE_DEVICE_TABLE(of, gcc_ipq4019_match_table); +int cpu_clk_notifier_fn(struct notifier_block *nb, + unsigned long action, void *data) +{ + int err = 0; + + if (action == PRE_RATE_CHANGE) { + err = clk_rcg2_ops.set_parent(&apps_clk_src.clkr.hw, + P_FEPLL500); + } + + return notifier_from_errno(err); +} + +struct notifier_block cpu_clk_notifier = { + .notifier_call = cpu_clk_notifier_fn, +}; + static int gcc_ipq4019_probe(struct platform_device *pdev) { - return qcom_cc_probe(pdev, &gcc_ipq4019_desc); + int err; + + err = qcom_cc_probe(pdev, &gcc_ipq4019_desc); + + if (!err) + clk_notifier_register(apps_clk_src.clkr.hw.clk, + &cpu_clk_notifier); + + return err; } static struct platform_driver gcc_ipq4019_driver = {