drivers/cpufreq/loongson3_cpufreq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CPUFreq driver for the Loongson-3 processors.
   4  *
   5  * All revisions of Loongson-3 processor support cpu_has_scalefreq feature.
   6  *
   7  * Author: Huacai Chen <chenhuacai@loongson.cn>
   8  * Copyright (C) 2024 Loongson Technology Corporation Limited
   9  */
  10 #include <linux/cpufreq.h>
  11 #include <linux/delay.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/units.h>
  15
  16 #include <asm/idle.h>
  17 #include <asm/loongarch.h>
  18 #include <asm/loongson.h>
  19
  20 /* Message */
  21 union smc_message {
  22         u32 value;
  23         struct {
  24                 u32 id          : 4;
  25                 u32 info        : 4;
  26                 u32 val         : 16;
  27                 u32 cmd         : 6;
  28                 u32 extra       : 1;
  29                 u32 complete    : 1;
  30         };
  31 };
  32
  33 /* Command return values */
  34 #define CMD_OK                          0 /* No error */
  35 #define CMD_ERROR                       1 /* Regular error */
  36 #define CMD_NOCMD                       2 /* Command does not support */
  37 #define CMD_INVAL                       3 /* Invalid Parameter */
  38
  39 /* Version commands */
  40 /*
  41  * CMD_GET_VERSION - Get interface version
  42  * Input: none
  43  * Output: version
  44  */
  45 #define CMD_GET_VERSION                 0x1
  46
  47 /* Feature commands */
  48 /*
  49  * CMD_GET_FEATURE - Get feature state
  50  * Input: feature ID
  51  * Output: feature flag
  52  */
  53 #define CMD_GET_FEATURE                 0x2
  54
  55 /*
  56  * CMD_SET_FEATURE - Set feature state
  57  * Input: feature ID, feature flag
  58  * output: none
  59  */
  60 #define CMD_SET_FEATURE                 0x3
  61
  62 /* Feature IDs */
  63 #define FEATURE_SENSOR                  0
  64 #define FEATURE_FAN                     1
  65 #define FEATURE_DVFS                    2
  66
  67 /* Sensor feature flags */
  68 #define FEATURE_SENSOR_ENABLE           BIT(0)
  69 #define FEATURE_SENSOR_SAMPLE           BIT(1)
  70
  71 /* Fan feature flags */
  72 #define FEATURE_FAN_ENABLE              BIT(0)
  73 #define FEATURE_FAN_AUTO                BIT(1)
  74
  75 /* DVFS feature flags */
  76 #define FEATURE_DVFS_ENABLE             BIT(0)
  77 #define FEATURE_DVFS_BOOST              BIT(1)
  78 #define FEATURE_DVFS_AUTO               BIT(2)
  79 #define FEATURE_DVFS_SINGLE_BOOST       BIT(3)
  80
  81 /* Sensor commands */
  82 /*
  83  * CMD_GET_SENSOR_NUM - Get number of sensors
  84  * Input: none
  85  * Output: number
  86  */
  87 #define CMD_GET_SENSOR_NUM              0x4
  88
  89 /*
  90  * CMD_GET_SENSOR_STATUS - Get sensor status
  91  * Input: sensor ID, type
  92  * Output: sensor status
  93  */
  94 #define CMD_GET_SENSOR_STATUS           0x5
  95
  96 /* Sensor types */
  97 #define SENSOR_INFO_TYPE                0
  98 #define SENSOR_INFO_TYPE_TEMP           1
  99
 100 /* Fan commands */
 101 /*
 102  * CMD_GET_FAN_NUM - Get number of fans
 103  * Input: none
 104  * Output: number
 105  */
 106 #define CMD_GET_FAN_NUM                 0x6
 107
 108 /*
 109  * CMD_GET_FAN_INFO - Get fan status
 110  * Input: fan ID, type
 111  * Output: fan info
 112  */
 113 #define CMD_GET_FAN_INFO                0x7
 114
 115 /*
 116  * CMD_SET_FAN_INFO - Set fan status
 117  * Input: fan ID, type, value
 118  * Output: none
 119  */
 120 #define CMD_SET_FAN_INFO                0x8
 121
 122 /* Fan types */
 123 #define FAN_INFO_TYPE_LEVEL             0
 124
 125 /* DVFS commands */
 126 /*
 127  * CMD_GET_FREQ_LEVEL_NUM - Get number of freq levels
 128  * Input: CPU ID
 129  * Output: number
 130  */
 131 #define CMD_GET_FREQ_LEVEL_NUM          0x9
 132
 133 /*
 134  * CMD_GET_FREQ_BOOST_LEVEL - Get the first boost level
 135  * Input: CPU ID
 136  * Output: number
 137  */
 138 #define CMD_GET_FREQ_BOOST_LEVEL        0x10
 139
 140 /*
 141  * CMD_GET_FREQ_LEVEL_INFO - Get freq level info
 142  * Input: CPU ID, level ID
 143  * Output: level info
 144  */
 145 #define CMD_GET_FREQ_LEVEL_INFO         0x11
 146
 147 /*
 148  * CMD_GET_FREQ_INFO - Get freq info
 149  * Input: CPU ID, type
 150  * Output: freq info
 151  */
 152 #define CMD_GET_FREQ_INFO               0x12
 153
 154 /*
 155  * CMD_SET_FREQ_INFO - Set freq info
 156  * Input: CPU ID, type, value
 157  * Output: none
 158  */
 159 #define CMD_SET_FREQ_INFO               0x13
 160
 161 /* Freq types */
 162 #define FREQ_INFO_TYPE_FREQ             0
 163 #define FREQ_INFO_TYPE_LEVEL            1
 164
 165 #define FREQ_MAX_LEVEL                  16
 166
 167 struct loongson3_freq_data {
 168         unsigned int def_freq_level;
 169         struct cpufreq_frequency_table table[];
 170 };
 171
 172 static struct mutex cpufreq_mutex[MAX_PACKAGES];
 173 static struct cpufreq_driver loongson3_cpufreq_driver;
 174 static DEFINE_PER_CPU(struct loongson3_freq_data *, freq_data);
 175
 176 static inline int do_service_request(u32 id, u32 info, u32 cmd, u32 val, u32 extra)
 177 {
 178         int retries;
 179         unsigned int cpu = raw_smp_processor_id();
 180         unsigned int package = cpu_data[cpu].package;
 181         union smc_message msg, last;
 182
 183         mutex_lock(&cpufreq_mutex[package]);
 184
 185         last.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
 186         if (!last.complete) {
 187                 mutex_unlock(&cpufreq_mutex[package]);
 188                 return -EPERM;
 189         }
 190
 191         msg.id          = id;
 192         msg.info        = info;
 193         msg.cmd         = cmd;
 194         msg.val         = val;
 195         msg.extra       = extra;
 196         msg.complete    = 0;
 197
 198         iocsr_write32(msg.value, LOONGARCH_IOCSR_SMCMBX);
 199         iocsr_write32(iocsr_read32(LOONGARCH_IOCSR_MISC_FUNC) | IOCSR_MISC_FUNC_SOFT_INT,
 200                       LOONGARCH_IOCSR_MISC_FUNC);
 201
 202         for (retries = 0; retries < 10000; retries++) {
 203                 msg.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
 204                 if (msg.complete)
 205                         break;
 206
 207                 usleep_range(8, 12);
 208         }
 209
 210         if (!msg.complete || msg.cmd != CMD_OK) {
 211                 mutex_unlock(&cpufreq_mutex[package]);
 212                 return -EPERM;
 213         }
 214
 215         mutex_unlock(&cpufreq_mutex[package]);
 216
 217         return msg.val;
 218 }
 219
 220 static unsigned int loongson3_cpufreq_get(unsigned int cpu)
 221 {
 222         int ret;
 223
 224         ret = do_service_request(cpu, FREQ_INFO_TYPE_FREQ, CMD_GET_FREQ_INFO, 0, 0);
 225
 226         return ret * KILO;
 227 }
 228
 229 static int loongson3_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
 230 {
 231         int ret;
 232
 233         ret = do_service_request(cpu_data[policy->cpu].core,
 234                                  FREQ_INFO_TYPE_LEVEL, CMD_SET_FREQ_INFO, index, 0);
 235
 236         return (ret >= 0) ? 0 : ret;
 237 }
 238
 239 static int configure_freq_table(int cpu)
 240 {
 241         int i, ret, boost_level, max_level, freq_level;
 242         struct platform_device *pdev = cpufreq_get_driver_data();
 243         struct loongson3_freq_data *data;
 244
 245         if (per_cpu(freq_data, cpu))
 246                 return 0;
 247
 248         ret = do_service_request(cpu, 0, CMD_GET_FREQ_LEVEL_NUM, 0, 0);
 249         if (ret < 0)
 250                 return ret;
 251         max_level = ret;
 252
 253         ret = do_service_request(cpu, 0, CMD_GET_FREQ_BOOST_LEVEL, 0, 0);
 254         if (ret < 0)
 255                 return ret;
 256         boost_level = ret;
 257
 258         freq_level = min(max_level, FREQ_MAX_LEVEL);
 259         data = devm_kzalloc(&pdev->dev, struct_size(data, table, freq_level + 1), GFP_KERNEL);
 260         if (!data)
 261                 return -ENOMEM;
 262
 263         data->def_freq_level = boost_level - 1;
 264
 265         for (i = 0; i < freq_level; i++) {
 266                 ret = do_service_request(cpu, FREQ_INFO_TYPE_FREQ, CMD_GET_FREQ_LEVEL_INFO, i, 0);
 267                 if (ret < 0) {
 268                         devm_kfree(&pdev->dev, data);
 269                         return ret;
 270                 }
 271
 272                 data->table[i].frequency = ret * KILO;
 273                 data->table[i].flags = (i >= boost_level) ? CPUFREQ_BOOST_FREQ : 0;
 274         }
 275
 276         data->table[freq_level].flags = 0;
 277         data->table[freq_level].frequency = CPUFREQ_TABLE_END;
 278
 279         per_cpu(freq_data, cpu) = data;
 280
 281         return 0;
 282 }
 283
 284 static int loongson3_cpufreq_cpu_init(struct cpufreq_policy *policy)
 285 {
 286         int i, ret, cpu = policy->cpu;
 287
 288         ret = configure_freq_table(cpu);
 289         if (ret < 0)
 290                 return ret;
 291
 292         policy->cpuinfo.transition_latency = 10000;
 293         policy->freq_table = per_cpu(freq_data, cpu)->table;
 294         policy->suspend_freq = policy->freq_table[per_cpu(freq_data, cpu)->def_freq_level].frequency;
 295         cpumask_copy(policy->cpus, topology_sibling_cpumask(cpu));
 296
 297         for_each_cpu(i, policy->cpus) {
 298                 if (i != cpu)
 299                         per_cpu(freq_data, i) = per_cpu(freq_data, cpu);
 300         }
 301
 302         if (policy_has_boost_freq(policy)) {
 303                 ret = cpufreq_enable_boost_support();
 304                 if (ret < 0) {
 305                         pr_warn("cpufreq: Failed to enable boost: %d\n", ret);
 306                         return ret;
 307                 }
 308                 loongson3_cpufreq_driver.boost_enabled = true;
 309         }
 310
 311         return 0;
 312 }
 313
 314 static void loongson3_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 315 {
 316         int cpu = policy->cpu;
 317
 318         loongson3_cpufreq_target(policy, per_cpu(freq_data, cpu)->def_freq_level);
 319 }
 320
 321 static int loongson3_cpufreq_cpu_online(struct cpufreq_policy *policy)
 322 {
 323         return 0;
 324 }
 325
 326 static int loongson3_cpufreq_cpu_offline(struct cpufreq_policy *policy)
 327 {
 328         return 0;
 329 }
 330
 331 static struct cpufreq_driver loongson3_cpufreq_driver = {
 332         .name = "loongson3",
 333         .flags = CPUFREQ_CONST_LOOPS,
 334         .init = loongson3_cpufreq_cpu_init,
 335         .exit = loongson3_cpufreq_cpu_exit,
 336         .online = loongson3_cpufreq_cpu_online,
 337         .offline = loongson3_cpufreq_cpu_offline,
 338         .get = loongson3_cpufreq_get,
 339         .target_index = loongson3_cpufreq_target,
 340         .attr = cpufreq_generic_attr,
 341         .verify = cpufreq_generic_frequency_table_verify,
 342         .suspend = cpufreq_generic_suspend,
 343 };
 344
 345 static int loongson3_cpufreq_probe(struct platform_device *pdev)
 346 {
 347         int i, ret;
 348
 349         for (i = 0; i < MAX_PACKAGES; i++)
 350                 devm_mutex_init(&pdev->dev, &cpufreq_mutex[i]);
 351
 352         ret = do_service_request(0, 0, CMD_GET_VERSION, 0, 0);
 353         if (ret <= 0)
 354                 return -EPERM;
 355
 356         ret = do_service_request(FEATURE_DVFS, 0, CMD_SET_FEATURE,
 357                                  FEATURE_DVFS_ENABLE | FEATURE_DVFS_BOOST, 0);
 358         if (ret < 0)
 359                 return -EPERM;
 360
 361         loongson3_cpufreq_driver.driver_data = pdev;
 362
 363         ret = cpufreq_register_driver(&loongson3_cpufreq_driver);
 364         if (ret)
 365                 return ret;
 366
 367         pr_info("cpufreq: Loongson-3 CPU frequency driver.\n");
 368
 369         return 0;
 370 }
 371
 372 static void loongson3_cpufreq_remove(struct platform_device *pdev)
 373 {
 374         cpufreq_unregister_driver(&loongson3_cpufreq_driver);
 375 }
 376
 377 static struct platform_device_id cpufreq_id_table[] = {
 378         { "loongson3_cpufreq", },
 379         { /* sentinel */ }
 380 };
 381 MODULE_DEVICE_TABLE(platform, cpufreq_id_table);
 382
 383 static struct platform_driver loongson3_platform_driver = {
 384         .driver = {
 385                 .name = "loongson3_cpufreq",
 386         },
 387         .id_table = cpufreq_id_table,
 388         .probe = loongson3_cpufreq_probe,
 389         .remove_new = loongson3_cpufreq_remove,
 390 };
 391 module_platform_driver(loongson3_platform_driver);
 392
 393 MODULE_AUTHOR("Huacai Chen <chenhuacai@loongson.cn>");
 394 MODULE_DESCRIPTION("CPUFreq driver for Loongson-3 processors");
 395 MODULE_LICENSE("GPL");