// SPDX-License-Identifier: GPL-2.0-only
/*
* CPUFreq driver for the Loongson-3 processors.
*
* All revisions of Loongson-3 processor support cpu_has_scalefreq feature.
*
* Author: Huacai Chen <[email protected]>
* Copyright (C) 2024 Loongson Technology Corporation Limited
*/
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/units.h>
#include <asm/idle.h>
#include <asm/loongarch.h>
#include <asm/loongson.h>
/* Message */
union smc_message {
u32 value;
struct {
u32 id : 4;
u32 info : 4;
u32 val : 16;
u32 cmd : 6;
u32 extra : 1;
u32 complete : 1;
};
};
/* Command return values */
#define CMD_OK 0 /* No error */
#define CMD_ERROR 1 /* Regular error */
#define CMD_NOCMD 2 /* Command does not support */
#define CMD_INVAL 3 /* Invalid Parameter */
/* Version commands */
/*
* CMD_GET_VERSION - Get interface version
* Input: none
* Output: version
*/
#define CMD_GET_VERSION 0x1
/* Feature commands */
/*
* CMD_GET_FEATURE - Get feature state
* Input: feature ID
* Output: feature flag
*/
#define CMD_GET_FEATURE 0x2
/*
* CMD_SET_FEATURE - Set feature state
* Input: feature ID, feature flag
* output: none
*/
#define CMD_SET_FEATURE 0x3
/* Feature IDs */
#define FEATURE_SENSOR 0
#define FEATURE_FAN 1
#define FEATURE_DVFS 2
/* Sensor feature flags */
#define FEATURE_SENSOR_ENABLE BIT(0)
#define FEATURE_SENSOR_SAMPLE BIT(1)
/* Fan feature flags */
#define FEATURE_FAN_ENABLE BIT(0)
#define FEATURE_FAN_AUTO BIT(1)
/* DVFS feature flags */
#define FEATURE_DVFS_ENABLE BIT(0)
#define FEATURE_DVFS_BOOST BIT(1)
#define FEATURE_DVFS_AUTO BIT(2)
#define FEATURE_DVFS_SINGLE_BOOST BIT(3)
/* Sensor commands */
/*
* CMD_GET_SENSOR_NUM - Get number of sensors
* Input: none
* Output: number
*/
#define CMD_GET_SENSOR_NUM 0x4
/*
* CMD_GET_SENSOR_STATUS - Get sensor status
* Input: sensor ID, type
* Output: sensor status
*/
#define CMD_GET_SENSOR_STATUS 0x5
/* Sensor types */
#define SENSOR_INFO_TYPE 0
#define SENSOR_INFO_TYPE_TEMP 1
/* Fan commands */
/*
* CMD_GET_FAN_NUM - Get number of fans
* Input: none
* Output: number
*/
#define CMD_GET_FAN_NUM 0x6
/*
* CMD_GET_FAN_INFO - Get fan status
* Input: fan ID, type
* Output: fan info
*/
#define CMD_GET_FAN_INFO 0x7
/*
* CMD_SET_FAN_INFO - Set fan status
* Input: fan ID, type, value
* Output: none
*/
#define CMD_SET_FAN_INFO 0x8
/* Fan types */
#define FAN_INFO_TYPE_LEVEL 0
/* DVFS commands */
/*
* CMD_GET_FREQ_LEVEL_NUM - Get number of freq levels
* Input: CPU ID
* Output: number
*/
#define CMD_GET_FREQ_LEVEL_NUM 0x9
/*
* CMD_GET_FREQ_BOOST_LEVEL - Get the first boost level
* Input: CPU ID
* Output: number
*/
#define CMD_GET_FREQ_BOOST_LEVEL 0x10
/*
* CMD_GET_FREQ_LEVEL_INFO - Get freq level info
* Input: CPU ID, level ID
* Output: level info
*/
#define CMD_GET_FREQ_LEVEL_INFO 0x11
/*
* CMD_GET_FREQ_INFO - Get freq info
* Input: CPU ID, type
* Output: freq info
*/
#define CMD_GET_FREQ_INFO 0x12
/*
* CMD_SET_FREQ_INFO - Set freq info
* Input: CPU ID, type, value
* Output: none
*/
#define CMD_SET_FREQ_INFO 0x13
/* Freq types */
#define FREQ_INFO_TYPE_FREQ 0
#define FREQ_INFO_TYPE_LEVEL 1
#define FREQ_MAX_LEVEL 16
struct loongson3_freq_data {
unsigned int def_freq_level;
struct cpufreq_frequency_table table[];
};
static struct mutex cpufreq_mutex[MAX_PACKAGES];
static struct cpufreq_driver loongson3_cpufreq_driver;
static DEFINE_PER_CPU(struct loongson3_freq_data *, freq_data);
static inline int do_service_request(u32 id, u32 info, u32 cmd, u32 val, u32 extra)
{
int retries;
unsigned int cpu = raw_smp_processor_id();
unsigned int package = cpu_data[cpu].package;
union smc_message msg, last;
mutex_lock(&cpufreq_mutex[package]);
last.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
if (!last.complete) {
mutex_unlock(&cpufreq_mutex[package]);
return -EPERM;
}
msg.id = id;
msg.info = info;
msg.cmd = cmd;
msg.val = val;
msg.extra = extra;
msg.complete = 0;
iocsr_write32(msg.value, LOONGARCH_IOCSR_SMCMBX);
iocsr_write32(iocsr_read32(LOONGARCH_IOCSR_MISC_FUNC) | IOCSR_MISC_FUNC_SOFT_INT,
LOONGARCH_IOCSR_MISC_FUNC);
for (retries = 0; retries < 10000; retries++) {
msg.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
if (msg.complete)
break;
usleep_range(8, 12);
}
if (!msg.complete || msg.cmd != CMD_OK) {
mutex_unlock(&cpufreq_mutex[package]);
return -EPERM;
}
mutex_unlock(&cpufreq_mutex[package]);
return msg.val;
}
static unsigned int loongson3_cpufreq_get(unsigned int cpu)
{
int ret;
ret = do_service_request(cpu, FREQ_INFO_TYPE_FREQ, CMD_GET_FREQ_INFO, 0, 0);
return ret * KILO;
}
static int loongson3_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
{
int ret;
ret = do_service_request(cpu_data[policy->cpu].core,
FREQ_INFO_TYPE_LEVEL, CMD_SET_FREQ_INFO, index, 0);
return (ret >= 0) ? 0 : ret;
}
static int configure_freq_table(int cpu)
{
int i, ret, boost_level, max_level, freq_level;
struct platform_device *pdev = cpufreq_get_driver_data();
struct loongson3_freq_data *data;
if (per_cpu(freq_data, cpu))
return 0;
ret = do_service_request(cpu, 0, CMD_GET_FREQ_LEVEL_NUM, 0, 0);
if (ret < 0)
return ret;
max_level = ret;
ret = do_service_request(cpu, 0, CMD_GET_FREQ_BOOST_LEVEL, 0, 0);
if (ret < 0)
return ret;
boost_level = ret;
freq_level = min(max_level, FREQ_MAX_LEVEL);
data = devm_kzalloc(&pdev->dev, struct_size(data, table, freq_level + 1), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->def_freq_level = boost_level - 1;
for (i = 0; i < freq_level; i++) {
ret = do_service_request(cpu, FREQ_INFO_TYPE_FREQ, CMD_GET_FREQ_LEVEL_INFO, i, 0);
if (ret < 0) {
devm_kfree(&pdev->dev, data);
return ret;
}
data->table[i].frequency = ret * KILO;
data->table[i].flags = (i >= boost_level) ? CPUFREQ_BOOST_FREQ : 0;
}
data->table[freq_level].flags = 0;
data->table[freq_level].frequency = CPUFREQ_TABLE_END;
per_cpu(freq_data, cpu) = data;
return 0;
}
static int loongson3_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
int i, ret, cpu = policy->cpu;
ret = configure_freq_table(cpu);
if (ret < 0)
return ret;
policy->cpuinfo.transition_latency = 10000;
policy->freq_table = per_cpu(freq_data, cpu)->table;
policy->suspend_freq = policy->freq_table[per_cpu(freq_data, cpu)->def_freq_level].frequency;
cpumask_copy(policy->cpus, topology_sibling_cpumask(cpu));
for_each_cpu(i, policy->cpus) {
if (i != cpu)
per_cpu(freq_data, i) = per_cpu(freq_data, cpu);
}
if (policy_has_boost_freq(policy)) {
ret = cpufreq_enable_boost_support();
if (ret < 0) {
pr_warn("cpufreq: Failed to enable boost: %d\n", ret);
return ret;
}
loongson3_cpufreq_driver.boost_enabled = true;
}
return 0;
}
static void loongson3_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
int cpu = policy->cpu;
loongson3_cpufreq_target(policy, per_cpu(freq_data, cpu)->def_freq_level);
}
static int loongson3_cpufreq_cpu_online(struct cpufreq_policy *policy)
{
return 0;
}
static int loongson3_cpufreq_cpu_offline(struct cpufreq_policy *policy)
{
return 0;
}
static struct cpufreq_driver loongson3_cpufreq_driver = {
.name = "loongson3",
.flags = CPUFREQ_CONST_LOOPS,
.init = loongson3_cpufreq_cpu_init,
.exit = loongson3_cpufreq_cpu_exit,
.online = loongson3_cpufreq_cpu_online,
.offline = loongson3_cpufreq_cpu_offline,
.get = loongson3_cpufreq_get,
.target_index = loongson3_cpufreq_target,
.attr = cpufreq_generic_attr,
.verify = cpufreq_generic_frequency_table_verify,
.suspend = cpufreq_generic_suspend,
};
static int loongson3_cpufreq_probe(struct platform_device *pdev)
{
int i, ret;
for (i = 0; i < MAX_PACKAGES; i++)
devm_mutex_init(&pdev->dev, &cpufreq_mutex[i]);
ret = do_service_request(0, 0, CMD_GET_VERSION, 0, 0);
if (ret <= 0)
return -EPERM;
ret = do_service_request(FEATURE_DVFS, 0, CMD_SET_FEATURE,
FEATURE_DVFS_ENABLE | FEATURE_DVFS_BOOST, 0);
if (ret < 0)
return -EPERM;
loongson3_cpufreq_driver.driver_data = pdev;
ret = cpufreq_register_driver(&loongson3_cpufreq_driver);
if (ret)
return ret;
pr_info("cpufreq: Loongson-3 CPU frequency driver.\n");
return 0;
}
static void loongson3_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&loongson3_cpufreq_driver);
}
static struct platform_device_id cpufreq_id_table[] = {
{ "loongson3_cpufreq", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, cpufreq_id_table);
static struct platform_driver loongson3_platform_driver = {
.driver = {
.name = "loongson3_cpufreq",
},
.id_table = cpufreq_id_table,
.probe = loongson3_cpufreq_probe,
.remove_new = loongson3_cpufreq_remove,
};
module_platform_driver(loongson3_platform_driver);
MODULE_AUTHOR("Huacai Chen <[email protected]>");
MODULE_DESCRIPTION("CPUFreq driver for Loongson-3 processors");
MODULE_LICENSE("GPL");
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