linux/drivers/cpufreq/vexpress-spc-cpufreq.c
Sudeep Holla d9975b0b07 cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table
Currently when performing random CPU hot-plugs and suspend-to-ram(S2R)
on systems using arm_big_little cpufreq driver, we get warnings similar
to something like below:

cpu cpu1: _opp_add: duplicate OPPs detected. Existing: freq: 600000000,
	volt: 800000, enabled: 1. New: freq: 600000000, volt: 800000, enabled: 1

This is mainly because the OPPs for the shared cpus are not set. We can
just use dev_pm_opp_of_cpumask_add_table in case the OPPs are obtained
from DT(arm_big_little_dt.c) or use dev_pm_opp_set_sharing_cpus if the
OPPs are obtained by other means like firmware(e.g. scpi-cpufreq.c)

Also now that the generic dev_pm_opp{,_of}_cpumask_remove_table can
handle removal of opp table and entries for all associated CPUs, we can
re-use dev_pm_opp{,_of}_cpumask_remove_table as free_opp_table in
cpufreq_arm_bL_ops.

This patch makes necessary changes to reuse the generic OPP functions for
{init,free}_opp_table and thereby eliminating the warnings.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-05 01:40:04 +02:00

72 lines
1.9 KiB
C

/*
* Versatile Express SPC CPUFreq Interface driver
*
* It provides necessary ops to arm_big_little cpufreq driver.
*
* Copyright (C) 2013 ARM Ltd.
* Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/types.h>
#include "arm_big_little.h"
static int ve_spc_init_opp_table(const struct cpumask *cpumask)
{
struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask));
/*
* platform specific SPC code must initialise the opp table
* so just check if the OPP count is non-zero
*/
return dev_pm_opp_get_opp_count(cpu_dev) <= 0;
}
static int ve_spc_get_transition_latency(struct device *cpu_dev)
{
return 1000000; /* 1 ms */
}
static struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = {
.name = "vexpress-spc",
.get_transition_latency = ve_spc_get_transition_latency,
.init_opp_table = ve_spc_init_opp_table,
};
static int ve_spc_cpufreq_probe(struct platform_device *pdev)
{
return bL_cpufreq_register(&ve_spc_cpufreq_ops);
}
static int ve_spc_cpufreq_remove(struct platform_device *pdev)
{
bL_cpufreq_unregister(&ve_spc_cpufreq_ops);
return 0;
}
static struct platform_driver ve_spc_cpufreq_platdrv = {
.driver = {
.name = "vexpress-spc-cpufreq",
},
.probe = ve_spc_cpufreq_probe,
.remove = ve_spc_cpufreq_remove,
};
module_platform_driver(ve_spc_cpufreq_platdrv);
MODULE_LICENSE("GPL");