linux/drivers/opp/cpu.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic OPP helper interface for CPU device
 *
 * Copyright (C) 2009-2014 Texas Instruments Incorporated.
 *	Nishanth Menon
 *	Romit Dasgupta
 *	Kevin Hilman
 */

#define pr_fmt(fmt) …

#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/slab.h>

#include "opp.h"

#ifdef CONFIG_CPU_FREQ

/**
 * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
 * @dev:	device for which we do this operation
 * @opp_table:	Cpufreq table returned back to caller
 *
 * Generate a cpufreq table for a provided device- this assumes that the
 * opp table is already initialized and ready for usage.
 *
 * This function allocates required memory for the cpufreq table. It is
 * expected that the caller does the required maintenance such as freeing
 * the table as required.
 *
 * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
 * if no memory available for the operation (table is not populated), returns 0
 * if successful and table is populated.
 *
 * WARNING: It is  important for the callers to ensure refreshing their copy of
 * the table if any of the mentioned functions have been invoked in the interim.
 */
int dev_pm_opp_init_cpufreq_table(struct device *dev,
				  struct cpufreq_frequency_table **opp_table)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
 * @dev:	device for which we do this operation
 * @opp_table:	table to free
 *
 * Free up the table allocated by dev_pm_opp_init_cpufreq_table
 */
void dev_pm_opp_free_cpufreq_table(struct device *dev,
				   struct cpufreq_frequency_table **opp_table)
{ … }
EXPORT_SYMBOL_GPL(…);
#endif	/* CONFIG_CPU_FREQ */

void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask,
				      int last_cpu)
{ … }

/**
 * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask
 * @cpumask:	cpumask for which OPP table needs to be removed
 *
 * This removes the OPP tables for CPUs present in the @cpumask.
 * This should be used to remove all the OPPs entries associated with
 * the cpus in @cpumask.
 */
void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs
 * @cpu_dev:	CPU device for which we do this operation
 * @cpumask:	cpumask of the CPUs which share the OPP table with @cpu_dev
 *
 * This marks OPP table of the @cpu_dev as shared by the CPUs present in
 * @cpumask.
 *
 * Returns -ENODEV if OPP table isn't already present.
 */
int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
				const struct cpumask *cpumask)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
 * @cpu_dev:	CPU device for which we do this operation
 * @cpumask:	cpumask to update with information of sharing CPUs
 *
 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 *
 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
 * table's status is access-unknown.
 */
int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{ … }
EXPORT_SYMBOL_GPL(…);