From patchwork Thu Feb 24 08:11:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 546378 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 E206FC433F5 for ; Thu, 24 Feb 2022 08:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231233AbiBXINe (ORCPT ); Thu, 24 Feb 2022 03:13:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231728AbiBXIM2 (ORCPT ); Thu, 24 Feb 2022 03:12:28 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 06238108757; Thu, 24 Feb 2022 00:11:48 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C85DD1509; Thu, 24 Feb 2022 00:11:47 -0800 (PST) Received: from e123648.arm.com (unknown [10.57.8.211]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 91EBA3F70D; Thu, 24 Feb 2022 00:11:45 -0800 (PST) From: Lukasz Luba To: linux-kernel@vger.kernel.org Cc: lukasz.luba@arm.com, dietmar.eggemann@arm.com, viresh.kumar@linaro.org, rafael@kernel.org, daniel.lezcano@linaro.org, nm@ti.com, sboyd@kernel.org, mka@chromium.org, dianders@chromium.org, robh+dt@kernel.org, devicetree@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v3 3/4] OPP: Add support of "opp-microwatt" for advanced EM registration Date: Thu, 24 Feb 2022 08:11:30 +0000 Message-Id: <20220224081131.27282-4-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220224081131.27282-1-lukasz.luba@arm.com> References: <20220224081131.27282-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The Energy Model (EM) can be created based on DT entry: 'dynamic-power-coefficient'. It's a 'simple' EM which is limited to the dynamic power. It has to fit into the math formula which requires also information about voltage. Some of the platforms don't expose voltage information, thus it's not possible to use EM registration using DT. This patch aims to fix it. It introduces new implementation of the EM registration callback. The new mechanism relies on the new OPP feature allowing to get power (which is coming from "opp-microwatt" DT property) expressed in micro-Watts. The patch also opens new opportunity to better support platforms, which have a decent static power. It allows to register 'advanced' EM (based on real power measurements) which models total power (static + dynamic), so better reflects real HW. Signed-off-by: Lukasz Luba --- drivers/opp/of.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 7bff30f27dc1..af3488779867 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -1438,6 +1438,38 @@ struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp) } EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node); +/* + * Callback function provided to the Energy Model framework upon registration. + * It provides the power used by @dev at @kHz if it is the frequency of an + * existing OPP, or at the frequency of the first OPP above @kHz otherwise + * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled + * frequency and @mW to the associated power. + * + * Returns 0 on success or a proper -EINVAL value in case of error. + */ +static int __maybe_unused +_get_opp_power(unsigned long *mW, unsigned long *kHz, struct device *dev) +{ + struct dev_pm_opp *opp; + unsigned long opp_freq, opp_power; + + /* Find the right frequency and related OPP */ + opp_freq = *kHz * 1000; + opp = dev_pm_opp_find_freq_ceil(dev, &opp_freq); + if (IS_ERR(opp)) + return -EINVAL; + + opp_power = dev_pm_opp_get_power(opp); + dev_pm_opp_put(opp); + if (!opp_power) + return -EINVAL; + + *kHz = opp_freq / 1000; + *mW = opp_power / 1000; + + return 0; +} + /* * Callback function provided to the Energy Model framework upon registration. * This computes the power estimated by @dev at @kHz if it is the frequency @@ -1488,6 +1520,24 @@ static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz, return 0; } +static bool _of_has_opp_microwatt_property(struct device *dev) +{ + unsigned long power, freq = 0; + struct dev_pm_opp *opp; + + /* Check if at least one OPP has needed property */ + opp = dev_pm_opp_find_freq_ceil(dev, &freq); + if (IS_ERR(opp)) + return false; + + power = dev_pm_opp_get_power(opp); + dev_pm_opp_put(opp); + if (!power) + return false; + + return true; +} + /** * dev_pm_opp_of_register_em() - Attempt to register an Energy Model * @dev : Device for which an Energy Model has to be registered @@ -1517,6 +1567,14 @@ int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus) goto failed; } + /* First, try to find more precised Energy Model in DT */ + if (_of_has_opp_microwatt_property(dev)) { + struct em_data_callback em_dt_cb = EM_DATA_CB(_get_opp_power); + + return em_dev_register_perf_domain(dev, nr_opp, &em_dt_cb, + cpus, true); + } + np = of_node_get(dev->of_node); if (!np) { ret = -EINVAL;