diff options
Diffstat (limited to 'drivers/cpufreq/loongson3_cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/loongson3_cpufreq.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/cpufreq/loongson3_cpufreq.c b/drivers/cpufreq/loongson3_cpufreq.c new file mode 100644 index 000000000000..5f79b6de127c --- /dev/null +++ b/drivers/cpufreq/loongson3_cpufreq.c @@ -0,0 +1,395 @@ +// 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 <chenhuacai@loongson.cn> + * 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 = 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 <chenhuacai@loongson.cn>"); +MODULE_DESCRIPTION("CPUFreq driver for Loongson-3 processors"); +MODULE_LICENSE("GPL"); |