blob: d76e5e27533a65627644775e7050ecd5f3bc1f98 [file] [log] [blame]
/*
* Copyright (C) 2017-2018 NXP
*
* 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.
*/
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpu_cooling.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/suspend.h>
#include <linux/device_cooling.h>
static struct device *cpu_dev;
static bool free_opp;
static struct cpufreq_frequency_table *freq_table;
static unsigned int transition_latency;
static struct clk *a53_clk;
static struct clk *arm_a53_src_clk;
static struct clk *arm_pll_clk;
static struct clk *arm_pll_out_clk;
static struct clk *sys1_pll_800m_clk;
struct thermal_cooling_device *cdev;
static struct regulator *arm_reg;
static int imx8mq_set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct dev_pm_opp *opp;
unsigned long freq_hz, volt;
unsigned int old_freq, new_freq;
int ret;
new_freq = freq_table[index].frequency;
freq_hz = new_freq * 1000;
old_freq = policy->cur;
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
if (IS_ERR(opp)) {
dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
return PTR_ERR(opp);
}
volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
dev_dbg(cpu_dev, "%u MHz --> %u MHz\n",
old_freq / 1000, new_freq / 1000);
if (new_freq > old_freq) {
if (!IS_ERR(arm_reg)) {
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_err(cpu_dev, "failed to scale arm_reg up: %d\n", ret);
return ret;
}
} else {
dev_err(cpu_dev, "Can't change CPU voltage\n");
}
}
clk_set_parent(arm_a53_src_clk, sys1_pll_800m_clk);
clk_set_rate(arm_pll_clk, new_freq * 1000);
clk_set_parent(arm_a53_src_clk, arm_pll_out_clk);
if (new_freq < old_freq) {
if (!IS_ERR(arm_reg)) {
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_err(cpu_dev, "failed to scale arm_reg down: %d\n", ret);
return ret;
}
} else {
dev_err(cpu_dev, "Can't change CPU voltage\n");
}
}
/* Ensure the arm clock divider is what we expect */
ret = clk_set_rate(a53_clk, new_freq * 1000);
if (ret)
dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
return ret;
}
static void imx8mq_cpufreq_ready(struct cpufreq_policy *policy)
{
struct device_node *np = of_get_cpu_node(policy->cpu, NULL);
if (of_find_property(np, "#cooling-cells", NULL)) {
cdev = of_cpufreq_cooling_register(np, policy);
if (IS_ERR(cdev) && PTR_ERR(cdev) != -ENOSYS) {
pr_err("cpu%d is not running as cooling device: %ld\n",
policy->cpu, PTR_ERR(cdev));
cdev = NULL;
}
}
of_node_put(np);
}
#define cpu_cooling_core_mask ((1 << 2) | (1 << 3)) /* offline cpu2 and cpu3 if needed*/
static int thermal_hot_pm_notify(struct notifier_block *nb, unsigned long event,
void *dummy)
{
static unsigned long prev_event = 0xffffffff;
struct device *cpu_dev = NULL;
static int cpus_offlined = 0;
int i = 0, ret = 0;
if (event == prev_event)
return NOTIFY_OK;
prev_event = event;
switch (event) {
case 0: /* default state, no trip point reached*/
case 1: /* trip1 temperature are lower than trip2, we can
online the cpu2 and cpu3 to get better performance */
for (i = 0; i < num_possible_cpus(); i++) {
if (!(cpu_cooling_core_mask & BIT(i)))
continue;
if (!(cpus_offlined & BIT(i)))
continue;
cpus_offlined &= ~BIT(i);
pr_info("Allow Online CPU%d, devfreq state: %d\n",
i, event);
lock_device_hotplug();
if (cpu_online(i)) {
unlock_device_hotplug();
continue;
}
cpu_dev = get_cpu_device(i);
ret = device_online(cpu_dev);
if (ret)
pr_err("Error %d online core %d\n",
ret, i);
unlock_device_hotplug();
}
break;
case 2: /* rise above trip2 temperature, offline cpu2 and cpu3 to
to limit the max online cpu cores */
for (i = num_possible_cpus() - 1; i >= 0; i--) {
if (!(cpu_cooling_core_mask & BIT(i)))
continue;
if (cpus_offlined & BIT(i) && !cpu_online(i))
continue;
pr_info("Set Offline: CPU%d, devfreq state: %d\n",
i, event);
lock_device_hotplug();
if (cpu_online(i)) {
cpu_dev = get_cpu_device(i);
ret = device_offline(cpu_dev);
if (ret < 0)
pr_err("Error %d offline core %d\n",
ret, i);
}
unlock_device_hotplug();
cpus_offlined |= BIT(i);
}
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block thermal_hot_pm_notifier =
{
.notifier_call = thermal_hot_pm_notify,
};
static int imx8mq_cpufreq_init(struct cpufreq_policy *policy)
{
int ret;
policy->clk = a53_clk;
policy->cur = clk_get_rate(a53_clk) / 1000;
ret = cpufreq_generic_init(policy, freq_table, transition_latency);
if (ret) {
dev_err(cpu_dev, "imx8mq cpufreq init failed!\n");
return ret;
}
policy->suspend_freq = policy->max;
return 0;
}
static struct cpufreq_driver imx8mq_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = imx8mq_set_target,
.get = cpufreq_generic_get,
.init = imx8mq_cpufreq_init,
.name = "imx8mq-cpufreq",
.ready = imx8mq_cpufreq_ready,
.attr = cpufreq_generic_attr,
#ifdef CONFIG_PM
.suspend = cpufreq_generic_suspend,
#endif
};
static int imx8mq_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np;
int ret, num;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {
pr_err("failed to get cpu0 device\n");
return -ENODEV;
}
np = of_node_get(cpu_dev->of_node);
if (!np) {
dev_err(cpu_dev, "failed to find cpu0 node\n");
return -ENOENT;
}
a53_clk = clk_get(cpu_dev, "a53");
arm_a53_src_clk = clk_get(cpu_dev, "arm_a53_src");
arm_pll_clk = clk_get(cpu_dev, "arm_pll");
arm_pll_out_clk = clk_get(cpu_dev, "arm_pll_out");
sys1_pll_800m_clk = clk_get(cpu_dev, "sys1_pll_800m");
if (IS_ERR(a53_clk) || IS_ERR(arm_a53_src_clk)
|| IS_ERR(arm_pll_out_clk) || IS_ERR(arm_pll_clk)
|| IS_ERR(sys1_pll_800m_clk)) {
dev_err(cpu_dev, "failed to get clocks\n");
ret = -ENOENT;
goto put_clk;
}
arm_reg = regulator_get_optional(cpu_dev, "arm");
/*
* We expect an OPP table supplied by platform.
* Just, incase the platform did not supply the OPP
* table, it will try to get it.
*/
num = dev_pm_opp_get_opp_count(cpu_dev);
if (num < 0) {
ret = dev_pm_opp_of_add_table(cpu_dev);
if (ret < 0) {
dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
goto put_clk;
}
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out_free_opp;
}
if (of_property_read_u32(np, "clock-latency", &transition_latency))
transition_latency = CPUFREQ_ETERNAL;
ret = cpufreq_register_driver(&imx8mq_cpufreq_driver);
if (ret) {
dev_err(cpu_dev, "failed register driver: %d\n", ret);
goto free_freq_table;
}
of_node_put(np);
dev_info(cpu_dev, "registered imx8mq-cpufreq\n");
register_devfreq_cooling_notifier(&thermal_hot_pm_notifier);
return 0;
free_freq_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_opp:
dev_pm_opp_of_remove_table(cpu_dev);
put_clk:
if (!IS_ERR(a53_clk))
clk_put(a53_clk);
if (!IS_ERR(arm_a53_src_clk))
clk_put(arm_a53_src_clk);
if (!IS_ERR(arm_pll_clk))
clk_put(arm_pll_clk);
if (!IS_ERR(arm_pll_out_clk))
clk_put(arm_pll_out_clk);
if (!IS_ERR(sys1_pll_800m_clk))
clk_put(sys1_pll_800m_clk);
of_node_put(np);
return ret;
}
static int imx8mq_cpufreq_remove(struct platform_device *pdev)
{
unregister_devfreq_cooling_notifier(&thermal_hot_pm_notifier);
cpufreq_cooling_unregister(cdev);
cpufreq_unregister_driver(&imx8mq_cpufreq_driver);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
if (free_opp)
dev_pm_opp_of_remove_table(cpu_dev);
clk_put(a53_clk);
clk_put(arm_a53_src_clk);
clk_put(arm_pll_clk);
clk_put(arm_pll_out_clk);
clk_put(sys1_pll_800m_clk);
return 0;
}
static struct platform_driver imx8mq_cpufreq_platdrv = {
.driver = {
.name = "imx8mq-cpufreq",
},
.probe = imx8mq_cpufreq_probe,
.remove = imx8mq_cpufreq_remove,
};
module_platform_driver(imx8mq_cpufreq_platdrv);
MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
MODULE_DESCRIPTION("Freescale i.MX8MQ cpufreq driver");
MODULE_LICENSE("GPL");