alistair23-linux/drivers/cpufreq/scpi-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

118 lines
3 KiB
C

/*
* System Control and Power Interface (SCPI) based CPUFreq Interface driver
*
* It provides necessary ops to arm_big_little cpufreq driver.
*
* Copyright (C) 2015 ARM Ltd.
* Sudeep Holla <sudeep.holla@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/scpi_protocol.h>
#include <linux/types.h>
#include "arm_big_little.h"
static struct scpi_ops *scpi_ops;
static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev)
{
int domain = topology_physical_package_id(cpu_dev->id);
if (domain < 0)
return ERR_PTR(-EINVAL);
return scpi_ops->dvfs_get_info(domain);
}
static int scpi_get_transition_latency(struct device *cpu_dev)
{
struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
if (IS_ERR(info))
return PTR_ERR(info);
return info->latency;
}
static int scpi_init_opp_table(const struct cpumask *cpumask)
{
int idx, ret;
struct scpi_opp *opp;
struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask));
struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
if (IS_ERR(info))
return PTR_ERR(info);
if (!info->opps)
return -EIO;
for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000);
if (ret) {
dev_warn(cpu_dev, "failed to add opp %uHz %umV\n",
opp->freq, opp->m_volt);
while (idx-- > 0)
dev_pm_opp_remove(cpu_dev, (--opp)->freq);
return ret;
}
}
ret = dev_pm_opp_set_sharing_cpus(cpu_dev, cpumask);
if (ret)
dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
__func__, ret);
return ret;
}
static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = {
.name = "scpi",
.get_transition_latency = scpi_get_transition_latency,
.init_opp_table = scpi_init_opp_table,
.free_opp_table = dev_pm_opp_cpumask_remove_table,
};
static int scpi_cpufreq_probe(struct platform_device *pdev)
{
scpi_ops = get_scpi_ops();
if (!scpi_ops)
return -EIO;
return bL_cpufreq_register(&scpi_cpufreq_ops);
}
static int scpi_cpufreq_remove(struct platform_device *pdev)
{
bL_cpufreq_unregister(&scpi_cpufreq_ops);
scpi_ops = NULL;
return 0;
}
static struct platform_driver scpi_cpufreq_platdrv = {
.driver = {
.name = "scpi-cpufreq",
.owner = THIS_MODULE,
},
.probe = scpi_cpufreq_probe,
.remove = scpi_cpufreq_remove,
};
module_platform_driver(scpi_cpufreq_platdrv);
MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver");
MODULE_LICENSE("GPL v2");