/*
|
* 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",
|
},
|
.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");
|
