From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937280AbeE3IIq (ORCPT ); Wed, 30 May 2018 04:08:46 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:27785 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935833AbeE3IIX (ORCPT ); Wed, 30 May 2018 04:08:23 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20180530080820epoutp012dc1c06464bba98e16ba61f2bd85c936~zXa3yqTHV1164011640epoutp01X X-AuditID: b6c32a48-2fdff7000000105a-17-5b0e5bf0f228 MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="utf-8" Message-id: <5B0E5BF0.6010306@samsung.com> Date: Wed, 30 May 2018 17:08:16 +0900 From: Chanwoo Choi Organization: Samsung Electronics User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Matthias Kaehlcke Cc: MyungJoo Ham , Kyungmin Park , Arnd Bergmann , Greg Kroah-Hartman , Rob Herring , Mark Rutland , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Brian Norris , Douglas Anderson Subject: Re: [PATCH 09/11] misc: throttler: Add core support for non-thermal throttling In-reply-to: <20180529205748.GJ168650@google.com> X-Brightmail-Tracker: H4sIAAAAAAAAA02SW0wTQRSGM912tyjFpVycYMS6iXIx1F4oLAqGRNSN+kDiC9po3dCREmlL uq2KL6LVIiQSxEsiiiIImoKoiAYxCAKCMRYFgkJQXyqkokQRFJFQbbsafZr//POdk/lPRoxJ z+JR4lyTFVlMbB6FLxLe74qjE75oQ7SKh1NJ9EJ5D0E3TX0W0Ve6+0S0q+4xTttrbuG069gn gh5svYTT06e6AV37ul9AT992A3r06A2cPtHWTaQHMw2XGwAz/7McMBcL+4VMk7MYZ9orGwim tNkJmOmm6ExiF0o1IFaPLDJkyjbrc005adS2HbqNOk2SQpmgTKGTKZmJNaI0KmN7ZsLm3Dzf SynZATbP5rMyWY6j1m5ItZhtViQzmDlrGqVVKlVypSJZrlL5TvXudSqND9mLDOVlxcL8F4Xg 0JjzpqgQjO8rAUFiSCbCe7P9eAlYJJaSLQDOnS0W8sUsgC5nu68QByj7gIz3bwPYebkW93dL yFD448y7AIORK2D3wH6/jZFx0DNT/mfOWwDPVJcIeT4eTp+/FOgVkqug4/Urwq9xn9/uGQ74 S8iVcOiHG/h1BJkFH1z5HmDCyVj4fv4F8A/FyCoMTj6aFfkvwsidcLhtMqCDSCX0zlcQfgiS v3BY7/mJ8wkyYGVNDB85DE70NhO8XgbHnXcAzxcBOOOxi/iiDMAvz+4KeEoNx6+WCPhsIfBk 1wLBD5XAkw4pjzDw1VidgI/sBXCo8jheBpZX/Lelin9bqvhvS1UAc4JIlM8ZcxCnyk+Uc6yR s5ly5NlmYxMI/Mh4pgV09G3vBKQYUMESRZZEKxWxB7gCYyeAYowKl9jagrVSiZ4tOIwsZp3F loe4TqDxLfk0FhWRbfb9b5NVp9So1Go1rUlOUStSqKWSkSTvLimZw1rRfoTykeVvn0AcFFUI zmkvJNrla5YVjK5/s7Vxy5pv+kfeRnfEQPRsyNTL6wddoSPk5liD43P2xbinm3oWO9V9kw6N 48ZqT8aU/XmSo2OwvXpga6LxVKZe9+1J8MrUkcnxmfPuutKqPd7eIkdRzIcl9nTVx8jeiWdH aloX0JjLPZbeUf9VPtfooOcarlVSQs7AKuMxC8f+BqNDYGGnAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgkeLIzCtJLcpLzFFi42I5/e+xoO6HaL5og79bJS3+TjrGbrHp43tW i/lHzrFanF12kM2iefF6NouzTW/YLS7vmsNm8bn3CKPF0usXmSw+b3jMaHG7cQWbReveI+wO PB5r5q1h9Pj9axKjx+yGiywem1Z1snnsn7uG3aNvyypGj8+b5ALYo7hsUlJzMstSi/TtErgy Jk3oZCk438BY8XTVWtYGxmdpXYwcHBICJhLNlxS6GLk4hATWMUr8XNzM3sXIycErICjxY/I9 FpAaZgF5iSOXsiFMdYkpU3Ihyu8zSqxc/B+qXEvi87Q5bCA2i4CqRNv1a2BxNqD4/hc3wOL8 AooSV388ZgSZIyoQIdF9ohIkLCKgIfHk93lGkJnMAguYJV5M/MEKkhAWiJS4sfctK8Syf4wS B6cfZgFJcAoYSvz7PYt9AqPALCSnzkI4dRbCqQsYmVcxSqYWFOem5xYbFRjlpZbrFSfmFpfm pesl5+duYgTGy7bDWv07GB8viT/EKMDBqMTDaxDBGy3EmlhWXJl7iFGCg1lJhLd0L0+0EG9K YmVValF+fFFpTmrxIUZpDhYlcV7+/GORQgLpiSWp2ampBalFMFkmDk6pBsamXH/5uHW1HcdC bGQn7BG+N6HV28KetVW1YOPKhte9c+fJ+H3iLPnWOdfq7s2wL1+ObuNNP3+KOd/XfulNRVWe JJX/utK7Q+Qmqr+eKvQrzum49n297/rl00Ml7cyanmSufNc6q6hsSuEutj8zJBs91ya+9vMo vpD9RltY9U1de4v5qssGX5VYijMSDbWYi4oTATa5YQGTAgAA X-CMS-MailID: 20180530080816epcas2p1c057f5324c444b10da16f74aea262e9c X-Msg-Generator: CA CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20180525203233epcas1p2f6bd8aa08aa6f259428bf53784b656a9 References: <20180525203043.249193-1-mka@chromium.org> <20180525203043.249193-10-mka@chromium.org> <5B0BB095.4040106@samsung.com> <20180529205748.GJ168650@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2018년 05월 30일 05:57, Matthias Kaehlcke wrote: > On Mon, May 28, 2018 at 04:32:37PM +0900, Chanwoo Choi wrote: > >> IMHO, you better to split out the devfreq patches from >> 'throttler' patch set. Because I'm not sure throttler is either >> necessary or not. >> >> After finishing the review of 'throttler' patches without devfreq handling, >> it would be better for you to send devfreq patches separately. > > I could certainly try to get 'throttler' with only cpufreq support > merged, but that would kind of defeat the purpose. > > I first sent a RFC patch for the devfreq policy notifiers > (https://patchwork.kernel.org/patch/10401999/) to get an idea if this > is a reasonable path to pursue. In response you asked about "real code > and patches" and here it is :) > > For my use case throttler is not really useful without devfreq > support. In this sense I prefer to know 'early' if there are any > blocking issues, rather then making the effort to get a limited > version of the driver merged, and then learn that I wasted my own and > the reviewers time because it is a dead end. I'm never force to you. Just my opinion is how to make the patches including the new concept. Thanks for your explanation why you send the patch set with devfreq. > >> On 2018년 05월 26일 05:30, Matthias Kaehlcke wrote: >>> The purpose of the throttler is to provide support for non-thermal >>> throttling. Throttling is triggered by external event, e.g. the >>> detection of a high battery discharge current, close to the OCP limit >>> of the battery. The throttler is only in charge of the throttling, not >>> the monitoring, which is done by another (possibly platform specific) >>> driver. >>> >>> Signed-off-by: Matthias Kaehlcke >>> --- >>> drivers/misc/Kconfig | 1 + >>> drivers/misc/Makefile | 1 + >>> drivers/misc/throttler/Kconfig | 13 ++ >>> drivers/misc/throttler/Makefile | 1 + >>> drivers/misc/throttler/core.c | 373 ++++++++++++++++++++++++++++++++ >>> include/linux/throttler.h | 10 + >>> 6 files changed, 399 insertions(+) >>> create mode 100644 drivers/misc/throttler/Kconfig >>> create mode 100644 drivers/misc/throttler/Makefile >>> create mode 100644 drivers/misc/throttler/core.c >>> create mode 100644 include/linux/throttler.h >>> >>> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig >>> index 5d713008749b..691d9625d83c 100644 >>> --- a/drivers/misc/Kconfig >>> +++ b/drivers/misc/Kconfig >>> @@ -513,4 +513,5 @@ source "drivers/misc/echo/Kconfig" >>> source "drivers/misc/cxl/Kconfig" >>> source "drivers/misc/ocxl/Kconfig" >>> source "drivers/misc/cardreader/Kconfig" >>> +source "drivers/misc/throttler/Kconfig" >>> endmenu >>> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile >>> index 20be70c3f118..01a1714dd2ad 100644 >>> --- a/drivers/misc/Makefile >>> +++ b/drivers/misc/Makefile >>> @@ -57,3 +57,4 @@ obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o >>> obj-$(CONFIG_PCI_ENDPOINT_TEST) += pci_endpoint_test.o >>> obj-$(CONFIG_OCXL) += ocxl/ >>> obj-$(CONFIG_MISC_RTSX) += cardreader/ >>> +obj-y += throttler/ >>> diff --git a/drivers/misc/throttler/Kconfig b/drivers/misc/throttler/Kconfig >>> new file mode 100644 >>> index 000000000000..ef8388f6bc0a >>> --- /dev/null >>> +++ b/drivers/misc/throttler/Kconfig >>> @@ -0,0 +1,13 @@ >>> +menuconfig THROTTLER >>> + bool "Throttler support" >>> + default n >>> + depends on OF >>> + select CPU_FREQ >>> + select PM_DEVFREQ >>> + help >>> + This option enables core support for non-thermal throttling of CPUs >>> + and devfreq devices. >>> + >>> + Note that you also need a event monitor module usually called >>> + *_throttler. >>> + >>> diff --git a/drivers/misc/throttler/Makefile b/drivers/misc/throttler/Makefile >>> new file mode 100644 >>> index 000000000000..c8d920cee315 >>> --- /dev/null >>> +++ b/drivers/misc/throttler/Makefile >>> @@ -0,0 +1 @@ >>> +obj-$(CONFIG_THROTTLER) += core.o >>> diff --git a/drivers/misc/throttler/core.c b/drivers/misc/throttler/core.c >>> new file mode 100644 >>> index 000000000000..c058d03212b8 >>> --- /dev/null >>> +++ b/drivers/misc/throttler/core.c >>> @@ -0,0 +1,373 @@ >>> +/* >>> + * Core code for non-thermal throttling >>> + * >>> + * Copyright (C) 2018 Google, Inc. >>> + * >>> + * This software is licensed under the terms of the GNU General Public >>> + * License version 2, as published by the Free Software Foundation, and >>> + * may be copied, distributed, and modified under those terms. >>> + * >>> + * This program is distributed in the hope that it will be useful, >>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >>> + * GNU General Public License for more details. >>> + * >>> + */ >>> + >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +/* >>> + * Non-thermal throttling: throttling of system components in response to >>> + * external events (e.g. high battery discharge current). >>> + * >>> + * The throttler supports throttling through cpufreq and devfreq. Multiple >>> + * levels of throttling can be configured. At level 0 no throttling is >>> + * active on behalf of the throttler, for values > 0 throttling is typically >>> + * configured to be increasingly aggressive with each level. >>> + * The number of throttling levels is not limited by the throttler (though >>> + * it is likely limited by the throttling devices). It is not necessary to >>> + * configure the same number of levels for all throttling devices. If the >>> + * requested throttling level for a device is higher than the maximum level >>> + * of the device the throttler will sleect the maximum throttling level of >>> + * the device. >>> + * >>> + * Non-thermal throttling is split in two parts: >>> + * >>> + * - throttler core >>> + * - parses the thermal policy >>> + * - applies throttling settings for a requested level of throttling >>> + * >>> + * - event monitor driver >>> + * - monitors the events that trigger throttling >>> + * - determines the throttling level (often limited to on/off) >>> + * - requests throttler core to apply throttling settings >>> + * >>> + * It is possible for a system to have more than one throttler and the >>> + * throttlers may make use of the same throttling devices, in case of >>> + * conflicting settings for a device the more aggressive values will be >>> + * applied. >>> + * >>> + */ >>> + >>> +struct thrcfg { >>> + uint32_t *freqs; >>> + int num_levels; >>> +}; >>> + >>> +struct cpufreq_thrdev { >>> + uint32_t cpu; >>> + struct thrcfg cfg; >>> +}; >>> + >>> +struct devfreq_thrdev { >>> + struct devfreq *devfreq; >>> + struct thrcfg cfg; >>> + struct throttler *thr; >>> + struct notifier_block nb; >>> +}; >>> + >>> +struct __thr_cpufreq { >>> + struct cpufreq_thrdev *devs; >>> + int ndevs; >>> + struct notifier_block nb; >>> +}; >>> + >>> +struct __thr_devfreq { >>> + struct devfreq_thrdev *devs; >>> + int ndevs; >>> +}; >>> + >>> +struct throttler { >>> + struct device *dev; >>> + int level; >>> + struct __thr_cpufreq cpufreq; >>> + struct __thr_devfreq devfreq; >>> +}; >>> + >>> +static unsigned long thr_get_throttling_freq(struct thrcfg *cfg, int level) >>> +{ >>> + if (level == 0 ) { >>> + WARN(true, "level == 0"); >>> + return 0; >>> + } >>> + >>> + if (level <= cfg->num_levels) >>> + return cfg->freqs[level - 1]; >>> + else >>> + return cfg->freqs[cfg->num_levels - 1]; >>> +} >>> + >>> +static int thr_cpufreq_event(struct notifier_block *nb, >>> + unsigned long event, void *data) >>> +{ >>> + struct throttler *thr = >>> + container_of(nb, struct throttler, cpufreq.nb); >>> + struct cpufreq_policy *policy = data; >>> + struct cpufreq_thrdev *ctd; >>> + int i; >>> + >>> + if ((event != CPUFREQ_ADJUST) || (thr->level == 0)) >>> + return NOTIFY_DONE; >>> + >>> + for (i = 0; i < thr->cpufreq.ndevs; i++) { >>> + ctd = &thr->cpufreq.devs[i]; >>> + >>> + if (ctd->cpu == policy->cpu) { >>> + unsigned long clamp_freq = >>> + thr_get_throttling_freq(&ctd->cfg, thr->level); >>> + if (clamp_freq < policy->max) { >>> + cpufreq_verify_within_limits(policy, 0, clamp_freq); >>> + } >>> + } >>> + } >>> + >>> + return NOTIFY_DONE; >>> +} >>> + >>> +static int thr_devfreq_event(struct notifier_block *nb, >>> + unsigned long event, void *data) >>> +{ >>> + struct devfreq_thrdev *dtd = >>> + container_of(nb, struct devfreq_thrdev, nb); >>> + struct throttler *thr = dtd->thr; >>> + struct devfreq_policy *policy = data; >>> + unsigned long clamp_freq; >>> + >>> + if ((event != DEVFREQ_ADJUST) || (thr->level == 0)) >>> + return NOTIFY_DONE; >>> + >>> + clamp_freq = thr_get_throttling_freq(&dtd->cfg, thr->level); >>> + if (clamp_freq < policy->max) >>> + devfreq_verify_within_limits(policy, 0, clamp_freq); >>> + >>> + return NOTIFY_DONE; >>> +} >>> + >>> +static void thr_cpufreq_update_policy(struct throttler *thr) >>> +{ >>> + int i; >>> + >>> + for (i = 0; i < thr->cpufreq.ndevs; i++) { >>> + struct cpufreq_thrdev *ctd = &thr->cpufreq.devs[i]; >>> + struct cpufreq_policy *policy = cpufreq_cpu_get(ctd->cpu); >>> + >>> + if (!policy) { >>> + dev_warn(thr->dev, "CPU%d does have no cpufreq policy!\n", ctd->cpu); >>> + continue; >>> + } >>> + >>> + cpufreq_update_policy(ctd->cpu); >>> + cpufreq_cpu_put(policy); >>> + } >>> +} >>> + >>> +static int thr_parse_thrcfg(struct throttler *thr, >>> + struct device_node *np, struct thrcfg *cfg) { >>> + int err; >>> + >>> + cfg->num_levels = >>> + of_property_count_u32_elems(np, "throttling-frequencies"); >>> + if (cfg->num_levels < 0) { >>> + pr_err("%s: failed to determine number of throttling frequencies\n", >>> + np->full_name); >>> + return cfg->num_levels; >>> + } >>> + >>> + cfg->freqs = devm_kzalloc(thr->dev, >>> + cfg->num_levels * sizeof(u32), GFP_KERNEL); >>> + if (!cfg->freqs) >>> + return -ENOMEM; >>> + >>> + err = of_property_read_u32_array(np, "throttling-frequencies", >>> + cfg->freqs, cfg->num_levels); >>> + if (err) { >>> + pr_err("%s: failed to read throttling frequencies\n", np->full_name); >>> + return err; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static struct devfreq *thr_find_devfreq_dev(struct throttler *thr, >>> + struct device_node *np_df) { >>> + struct device_node *node; >>> + struct platform_device *pdev; >>> + >>> + node = of_parse_phandle(np_df, "device", 0); >>> + if (!node) { >>> + pr_err("%s: failed to get devfreq parent device\n", >>> + np_df->full_name); >>> + return ERR_PTR(-EINVAL); >>> + } >>> + >>> + pdev = of_find_device_by_node(node); >>> + if (!pdev) { >>> + pr_err("%s: could not find devfreq parent device\n", >>> + node->full_name); >>> + return ERR_PTR(-EINVAL); >>> + } >>> + >>> + return dev_to_devfreq(&pdev->dev); >>> +} >>> + >>> +static int thr_parse_dt(struct throttler *thr, struct device_node *np) >>> +{ >>> + struct device_node *node, *child; >>> + int err, i; >>> + >>> + node = of_get_child_by_name(np, "cpufreq"); >>> + if (node) { >>> + thr->cpufreq.ndevs = of_get_child_count(node); >>> + thr->cpufreq.devs = devm_kzalloc(thr->dev, >>> + sizeof(*thr->cpufreq.devs) * thr->cpufreq.ndevs, >>> + GFP_KERNEL); >>> + >>> + i = 0; >>> + for_each_child_of_node(node, child) { >>> + struct cpufreq_thrdev *ctd = &thr->cpufreq.devs[i]; >>> + >>> + err = of_property_read_u32(child, "cpu", &ctd->cpu); >>> + if (err) { >>> + pr_err("%s: failed to read CPU id\n", child->full_name); >>> + return err; >>> + } >>> + >>> + err = thr_parse_thrcfg(thr, child, &ctd->cfg); >>> + if (err) >>> + return err; >>> + >>> + i++; >>> + } >>> + } >>> + >>> + node = of_get_child_by_name(np, "devfreq"); >>> + if (node) { >>> + thr->devfreq.ndevs = of_get_child_count(node); >>> + thr->devfreq.devs = devm_kzalloc(thr->dev, >>> + sizeof(*thr->devfreq.devs) * thr->devfreq.ndevs, >>> + GFP_KERNEL); >>> + >>> + i = 0; >>> + for_each_child_of_node(node, child) { >>> + struct devfreq_thrdev *dtd = &thr->devfreq.devs[i]; >>> + >>> + dtd->thr = thr; >>> + >>> + dtd->devfreq = thr_find_devfreq_dev(thr, child); >>> + if (IS_ERR(dtd->devfreq)) >>> + return PTR_ERR(dtd->devfreq); >>> + >>> + err = thr_parse_thrcfg(thr, child, &dtd->cfg); >>> + if (err) >>> + return err; >>> + >>> + i++; >>> + } >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static void thr_update_devfreq(struct devfreq *devfreq) >>> +{ >>> + mutex_lock(&devfreq->lock); >>> + update_devfreq(devfreq); >>> + mutex_unlock(&devfreq->lock); >>> +} >>> + >>> +void throttler_set_level(struct throttler *thr, int level) >>> +{ >>> + int i; >>> + >>> + if (level == thr->level) >>> + return; >>> + >>> + dev_dbg(thr->dev, "throttling level: %d\n", level); >>> + thr->level = level; >>> + >>> + if (thr->cpufreq.ndevs > 0) >>> + thr_cpufreq_update_policy(thr); >>> + >>> + if (thr->devfreq.ndevs > 0) >>> + for (i = 0; i < thr->devfreq.ndevs; i++) >>> + thr_update_devfreq(thr->devfreq.devs[i].devfreq); >>> +} >>> +EXPORT_SYMBOL_GPL(throttler_set_level); >>> + >>> +struct throttler *throttler_setup(struct device *dev) >>> +{ >>> + struct throttler *thr; >>> + struct device_node *np = dev->of_node; >>> + int err, i; >>> + >>> + if (!np) >>> + /* should never happen */ >>> + return ERR_PTR(-EINVAL); >>> + >>> + thr = devm_kzalloc(dev, sizeof(*thr), GFP_KERNEL); >>> + if (!thr) >>> + return ERR_PTR(-ENOMEM); >>> + >>> + thr->dev = dev; >>> + >>> + err = thr_parse_dt(thr, np); >>> + if (err) >>> + return ERR_PTR(err); >>> + >>> + if (thr->cpufreq.ndevs > 0) { >>> + thr->cpufreq.nb.notifier_call = thr_cpufreq_event; >>> + err = cpufreq_register_notifier(&thr->cpufreq.nb, >>> + CPUFREQ_POLICY_NOTIFIER); >>> + if (err < 0) { >>> + dev_err(dev, "failed to register cpufreq notifier\n"); >>> + return ERR_PTR(err); >>> + } >>> + } >>> + >>> + for (i = 0; i < thr->devfreq.ndevs; i++) { >>> + struct devfreq_thrdev *dtd = &thr->devfreq.devs[i]; >>> + >>> + dtd->nb.notifier_call = thr_devfreq_event; >>> + err = devm_devfreq_register_notifier(dev, dtd->devfreq, >>> + &dtd->nb, DEVFREQ_POLICY_NOTIFIER); >>> + if (err < 0) { >>> + dev_err(dev, "failed to register devfreq notifier\n"); >>> + goto err_cpufreq_unregister; >>> + } >>> + } >>> + >>> + return thr; >>> + >>> +err_cpufreq_unregister: >>> + if (thr->cpufreq.ndevs > 0) >>> + cpufreq_unregister_notifier(&thr->cpufreq.nb, >>> + CPUFREQ_POLICY_NOTIFIER); >>> + >>> + return ERR_PTR(err); >>> +} >>> +EXPORT_SYMBOL_GPL(throttler_setup); >>> + >>> +void throttler_teardown(struct throttler *thr) >>> +{ >>> + int i; >>> + >>> + thr->level = 0; >>> + >>> + if (thr->cpufreq.ndevs > 0) { >>> + thr_cpufreq_update_policy(thr); >>> + >>> + cpufreq_unregister_notifier(&thr->cpufreq.nb, >>> + CPUFREQ_POLICY_NOTIFIER); >>> + } >>> + >>> + if (thr->devfreq.ndevs > 0) >>> + for (i = 0; i < thr->devfreq.ndevs; i++) >>> + thr_update_devfreq(thr->devfreq.devs[i].devfreq); >>> +} >>> +EXPORT_SYMBOL_GPL(throttler_teardown); >>> diff --git a/include/linux/throttler.h b/include/linux/throttler.h >>> new file mode 100644 >>> index 000000000000..cab8c466da4b >>> --- /dev/null >>> +++ b/include/linux/throttler.h >>> @@ -0,0 +1,10 @@ >>> +#ifndef __LINUX_THROTTLER_H__ >>> +#define __LINUX_THROTTLER_H__ >>> + >>> +struct throttler; >>> + >>> +extern struct throttler *throttler_setup(struct device *dev); >>> +extern void throttler_teardown(struct throttler *thr); >>> +extern void throttler_set_level(struct throttler *thr, int level); >>> + >>> +#endif /* __LINUX_THROTTLER_H__ */ >>> > > > -- Best Regards, Chanwoo Choi Samsung Electronics