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e1fae554fb
All CPUs present in 'allowed_cpus' share the same 'struct cpufreq_policy' structure and so calling cpufreq_update_policy() for each of them doesn't make sense. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
570 lines
16 KiB
C
570 lines
16 KiB
C
/*
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* linux/drivers/thermal/cpu_cooling.c
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*
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* Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com)
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* Copyright (C) 2012 Amit Daniel <amit.kachhap@linaro.org>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/module.h>
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#include <linux/thermal.h>
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#include <linux/cpufreq.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include <linux/cpu_cooling.h>
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/*
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* Cooling state <-> CPUFreq frequency
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*
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* Cooling states are translated to frequencies throughout this driver and this
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* is the relation between them.
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*
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* Highest cooling state corresponds to lowest possible frequency.
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*
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* i.e.
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* level 0 --> 1st Max Freq
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* level 1 --> 2nd Max Freq
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* ...
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*/
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/**
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* struct cpufreq_cooling_device - data for cooling device with cpufreq
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* @id: unique integer value corresponding to each cpufreq_cooling_device
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* registered.
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* @cool_dev: thermal_cooling_device pointer to keep track of the
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* registered cooling device.
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* @cpufreq_state: integer value representing the current state of cpufreq
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* cooling devices.
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* @cpufreq_val: integer value representing the absolute value of the clipped
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* frequency.
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* @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
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*
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* This structure is required for keeping information of each registered
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* cpufreq_cooling_device.
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*/
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struct cpufreq_cooling_device {
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int id;
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struct thermal_cooling_device *cool_dev;
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unsigned int cpufreq_state;
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unsigned int cpufreq_val;
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struct cpumask allowed_cpus;
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struct list_head node;
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};
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static DEFINE_IDR(cpufreq_idr);
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static DEFINE_MUTEX(cooling_cpufreq_lock);
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static unsigned int cpufreq_dev_count;
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static LIST_HEAD(cpufreq_dev_list);
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/**
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* get_idr - function to get a unique id.
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* @idr: struct idr * handle used to create a id.
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* @id: int * value generated by this function.
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*
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* This function will populate @id with an unique
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* id, using the idr API.
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*
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* Return: 0 on success, an error code on failure.
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*/
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static int get_idr(struct idr *idr, int *id)
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{
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int ret;
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mutex_lock(&cooling_cpufreq_lock);
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ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
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mutex_unlock(&cooling_cpufreq_lock);
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if (unlikely(ret < 0))
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return ret;
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*id = ret;
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return 0;
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}
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/**
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* release_idr - function to free the unique id.
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* @idr: struct idr * handle used for creating the id.
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* @id: int value representing the unique id.
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*/
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static void release_idr(struct idr *idr, int id)
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{
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mutex_lock(&cooling_cpufreq_lock);
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idr_remove(idr, id);
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mutex_unlock(&cooling_cpufreq_lock);
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}
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/* Below code defines functions to be used for cpufreq as cooling device */
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/**
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* is_cpufreq_valid - function to check frequency transitioning capability.
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* @cpu: cpu for which check is needed.
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*
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* This function will check the current state of the system if
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* it is capable of changing the frequency for a given @cpu.
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*
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* Return: 0 if the system is not currently capable of changing
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* the frequency of given cpu. !0 in case the frequency is changeable.
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*/
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static int is_cpufreq_valid(int cpu)
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{
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struct cpufreq_policy policy;
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return !cpufreq_get_policy(&policy, cpu);
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}
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enum cpufreq_cooling_property {
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GET_LEVEL,
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GET_FREQ,
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GET_MAXL,
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};
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/**
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* get_property - fetch a property of interest for a given cpu.
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* @cpu: cpu for which the property is required
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* @input: query parameter
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* @output: query return
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* @property: type of query (frequency, level, max level)
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*
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* This is the common function to
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* 1. get maximum cpu cooling states
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* 2. translate frequency to cooling state
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* 3. translate cooling state to frequency
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*
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* Note that the code may be not in good shape
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* but it is written in this way in order to:
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* a) reduce duplicate code as most of the code can be shared.
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* b) make sure the logic is consistent when translating between
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* cooling states and frequencies.
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*
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* Return: 0 on success, -EINVAL when invalid parameters are passed.
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*/
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static int get_property(unsigned int cpu, unsigned long input,
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unsigned int *output,
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enum cpufreq_cooling_property property)
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{
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int i;
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unsigned long max_level = 0, level = 0;
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unsigned int freq = CPUFREQ_ENTRY_INVALID;
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int descend = -1;
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struct cpufreq_frequency_table *pos, *table =
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cpufreq_frequency_get_table(cpu);
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if (!output)
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return -EINVAL;
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if (!table)
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return -EINVAL;
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cpufreq_for_each_valid_entry(pos, table) {
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/* ignore duplicate entry */
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if (freq == pos->frequency)
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continue;
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/* get the frequency order */
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if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)
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descend = freq > pos->frequency;
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freq = pos->frequency;
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max_level++;
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}
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/* No valid cpu frequency entry */
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if (max_level == 0)
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return -EINVAL;
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/* max_level is an index, not a counter */
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max_level--;
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/* get max level */
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if (property == GET_MAXL) {
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*output = (unsigned int)max_level;
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return 0;
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}
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if (property == GET_FREQ)
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level = descend ? input : (max_level - input);
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i = 0;
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cpufreq_for_each_valid_entry(pos, table) {
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/* ignore duplicate entry */
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if (freq == pos->frequency)
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continue;
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/* now we have a valid frequency entry */
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freq = pos->frequency;
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if (property == GET_LEVEL && (unsigned int)input == freq) {
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/* get level by frequency */
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*output = descend ? i : (max_level - i);
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return 0;
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}
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if (property == GET_FREQ && level == i) {
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/* get frequency by level */
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*output = freq;
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return 0;
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}
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i++;
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}
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return -EINVAL;
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}
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/**
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* cpufreq_cooling_get_level - for a given cpu, return the cooling level.
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* @cpu: cpu for which the level is required
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* @freq: the frequency of interest
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*
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* This function will match the cooling level corresponding to the
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* requested @freq and return it.
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*
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* Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
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* otherwise.
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*/
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unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
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{
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unsigned int val;
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if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
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return THERMAL_CSTATE_INVALID;
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return (unsigned long)val;
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}
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EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
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/**
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* get_cpu_frequency - get the absolute value of frequency from level.
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* @cpu: cpu for which frequency is fetched.
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* @level: cooling level
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*
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* This function matches cooling level with frequency. Based on a cooling level
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* of frequency, equals cooling state of cpu cooling device, it will return
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* the corresponding frequency.
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* e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
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*
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* Return: 0 on error, the corresponding frequency otherwise.
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*/
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static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
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{
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int ret = 0;
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unsigned int freq;
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ret = get_property(cpu, level, &freq, GET_FREQ);
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if (ret)
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return 0;
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return freq;
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}
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/**
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* cpufreq_apply_cooling - function to apply frequency clipping.
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* @cpufreq_device: cpufreq_cooling_device pointer containing frequency
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* clipping data.
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* @cooling_state: value of the cooling state.
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*
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* Function used to make sure the cpufreq layer is aware of current thermal
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* limits. The limits are applied by updating the cpufreq policy.
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*
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* Return: 0 on success, an error code otherwise (-EINVAL in case wrong
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* cooling state).
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*/
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static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
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unsigned long cooling_state)
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{
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unsigned int clip_freq;
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struct cpumask *mask = &cpufreq_device->allowed_cpus;
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unsigned int cpu = cpumask_any(mask);
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/* Check if the old cooling action is same as new cooling action */
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if (cpufreq_device->cpufreq_state == cooling_state)
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return 0;
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clip_freq = get_cpu_frequency(cpu, cooling_state);
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if (!clip_freq)
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return -EINVAL;
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cpufreq_device->cpufreq_state = cooling_state;
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cpufreq_device->cpufreq_val = clip_freq;
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if (is_cpufreq_valid(cpu))
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cpufreq_update_policy(cpu);
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return 0;
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}
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/**
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* cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
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* @nb: struct notifier_block * with callback info.
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* @event: value showing cpufreq event for which this function invoked.
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* @data: callback-specific data
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*
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* Callback to hijack the notification on cpufreq policy transition.
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* Every time there is a change in policy, we will intercept and
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* update the cpufreq policy with thermal constraints.
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*
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* Return: 0 (success)
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*/
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static int cpufreq_thermal_notifier(struct notifier_block *nb,
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unsigned long event, void *data)
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{
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struct cpufreq_policy *policy = data;
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unsigned long max_freq = 0;
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struct cpufreq_cooling_device *cpufreq_dev;
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if (event != CPUFREQ_ADJUST)
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return 0;
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mutex_lock(&cooling_cpufreq_lock);
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list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
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if (!cpumask_test_cpu(policy->cpu,
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&cpufreq_dev->allowed_cpus))
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continue;
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if (!cpufreq_dev->cpufreq_val)
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cpufreq_dev->cpufreq_val = get_cpu_frequency(
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cpumask_any(&cpufreq_dev->allowed_cpus),
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cpufreq_dev->cpufreq_state);
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max_freq = cpufreq_dev->cpufreq_val;
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if (policy->max != max_freq)
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cpufreq_verify_within_limits(policy, 0, max_freq);
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}
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mutex_unlock(&cooling_cpufreq_lock);
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return 0;
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}
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/* cpufreq cooling device callback functions are defined below */
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/**
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* cpufreq_get_max_state - callback function to get the max cooling state.
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* @cdev: thermal cooling device pointer.
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* @state: fill this variable with the max cooling state.
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*
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* Callback for the thermal cooling device to return the cpufreq
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* max cooling state.
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*
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* Return: 0 on success, an error code otherwise.
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*/
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static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
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struct cpumask *mask = &cpufreq_device->allowed_cpus;
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unsigned int cpu;
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unsigned int count = 0;
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int ret;
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cpu = cpumask_any(mask);
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ret = get_property(cpu, 0, &count, GET_MAXL);
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if (count > 0)
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*state = count;
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return ret;
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}
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/**
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* cpufreq_get_cur_state - callback function to get the current cooling state.
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* @cdev: thermal cooling device pointer.
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* @state: fill this variable with the current cooling state.
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*
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* Callback for the thermal cooling device to return the cpufreq
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* current cooling state.
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*
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* Return: 0 on success, an error code otherwise.
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*/
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static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
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*state = cpufreq_device->cpufreq_state;
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return 0;
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}
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/**
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* cpufreq_set_cur_state - callback function to set the current cooling state.
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* @cdev: thermal cooling device pointer.
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* @state: set this variable to the current cooling state.
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*
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* Callback for the thermal cooling device to change the cpufreq
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* current cooling state.
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*
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* Return: 0 on success, an error code otherwise.
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*/
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static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
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unsigned long state)
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{
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struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
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return cpufreq_apply_cooling(cpufreq_device, state);
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}
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/* Bind cpufreq callbacks to thermal cooling device ops */
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static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
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.get_max_state = cpufreq_get_max_state,
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.get_cur_state = cpufreq_get_cur_state,
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.set_cur_state = cpufreq_set_cur_state,
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};
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/* Notifier for cpufreq policy change */
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static struct notifier_block thermal_cpufreq_notifier_block = {
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.notifier_call = cpufreq_thermal_notifier,
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};
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/**
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* __cpufreq_cooling_register - helper function to create cpufreq cooling device
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* @np: a valid struct device_node to the cooling device device tree node
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* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
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* Normally this should be same as cpufreq policy->related_cpus.
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*
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* This interface function registers the cpufreq cooling device with the name
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* "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
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* cooling devices. It also gives the opportunity to link the cooling device
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* with a device tree node, in order to bind it via the thermal DT code.
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*
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* Return: a valid struct thermal_cooling_device pointer on success,
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* on failure, it returns a corresponding ERR_PTR().
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*/
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static struct thermal_cooling_device *
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__cpufreq_cooling_register(struct device_node *np,
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const struct cpumask *clip_cpus)
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{
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struct thermal_cooling_device *cool_dev;
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struct cpufreq_cooling_device *cpufreq_dev;
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char dev_name[THERMAL_NAME_LENGTH];
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int ret;
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if (!cpufreq_frequency_get_table(cpumask_first(clip_cpus))) {
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pr_debug("%s: CPUFreq table not found\n", __func__);
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return ERR_PTR(-EPROBE_DEFER);
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}
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cpufreq_dev = kzalloc(sizeof(*cpufreq_dev), GFP_KERNEL);
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if (!cpufreq_dev)
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return ERR_PTR(-ENOMEM);
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cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
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ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
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if (ret) {
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kfree(cpufreq_dev);
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return ERR_PTR(ret);
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}
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snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
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cpufreq_dev->id);
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cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
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&cpufreq_cooling_ops);
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if (IS_ERR(cool_dev)) {
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release_idr(&cpufreq_idr, cpufreq_dev->id);
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kfree(cpufreq_dev);
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return cool_dev;
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}
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cpufreq_dev->cool_dev = cool_dev;
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mutex_lock(&cooling_cpufreq_lock);
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/* Register the notifier for first cpufreq cooling device */
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if (cpufreq_dev_count == 0)
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cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
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CPUFREQ_POLICY_NOTIFIER);
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cpufreq_dev_count++;
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list_add(&cpufreq_dev->node, &cpufreq_dev_list);
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mutex_unlock(&cooling_cpufreq_lock);
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return cool_dev;
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}
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/**
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* cpufreq_cooling_register - function to create cpufreq cooling device.
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* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
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*
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* This interface function registers the cpufreq cooling device with the name
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* "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
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* cooling devices.
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*
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* Return: a valid struct thermal_cooling_device pointer on success,
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* on failure, it returns a corresponding ERR_PTR().
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*/
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struct thermal_cooling_device *
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cpufreq_cooling_register(const struct cpumask *clip_cpus)
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{
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return __cpufreq_cooling_register(NULL, clip_cpus);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
|
|
|
|
/**
|
|
* of_cpufreq_cooling_register - function to create cpufreq cooling device.
|
|
* @np: a valid struct device_node to the cooling device device tree node
|
|
* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
|
|
*
|
|
* This interface function registers the cpufreq cooling device with the name
|
|
* "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
|
|
* cooling devices. Using this API, the cpufreq cooling device will be
|
|
* linked to the device tree node provided.
|
|
*
|
|
* Return: a valid struct thermal_cooling_device pointer on success,
|
|
* on failure, it returns a corresponding ERR_PTR().
|
|
*/
|
|
struct thermal_cooling_device *
|
|
of_cpufreq_cooling_register(struct device_node *np,
|
|
const struct cpumask *clip_cpus)
|
|
{
|
|
if (!np)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return __cpufreq_cooling_register(np, clip_cpus);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
|
|
|
|
/**
|
|
* cpufreq_cooling_unregister - function to remove cpufreq cooling device.
|
|
* @cdev: thermal cooling device pointer.
|
|
*
|
|
* This interface function unregisters the "thermal-cpufreq-%x" cooling device.
|
|
*/
|
|
void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
|
|
{
|
|
struct cpufreq_cooling_device *cpufreq_dev;
|
|
|
|
if (!cdev)
|
|
return;
|
|
|
|
cpufreq_dev = cdev->devdata;
|
|
mutex_lock(&cooling_cpufreq_lock);
|
|
list_del(&cpufreq_dev->node);
|
|
cpufreq_dev_count--;
|
|
|
|
/* Unregister the notifier for the last cpufreq cooling device */
|
|
if (cpufreq_dev_count == 0)
|
|
cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
|
|
CPUFREQ_POLICY_NOTIFIER);
|
|
mutex_unlock(&cooling_cpufreq_lock);
|
|
|
|
thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
|
|
release_idr(&cpufreq_idr, cpufreq_dev->id);
|
|
kfree(cpufreq_dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);
|