drivers/cpufreq/qcom-cpufreq-hw.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <linux/bitfield.h>
   7 #include <linux/cpufreq.h>
   8 #include <linux/init.h>
   9 #include <linux/interconnect.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/of_address.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/pm_opp.h>
  15 #include <linux/slab.h>
  16
  17 #define LUT_MAX_ENTRIES                 40U
  18 #define LUT_SRC                         GENMASK(31, 30)
  19 #define LUT_L_VAL                       GENMASK(7, 0)
  20 #define LUT_CORE_COUNT                  GENMASK(18, 16)
  21 #define LUT_VOLT                        GENMASK(11, 0)
  22 #define CLK_HW_DIV                      2
  23 #define LUT_TURBO_IND                   1
  24
  25 struct qcom_cpufreq_soc_data {
  26         u32 reg_enable;
  27         u32 reg_freq_lut;
  28         u32 reg_volt_lut;
  29         u32 reg_perf_state;
  30         u8 lut_row_size;
  31 };
  32
  33 struct qcom_cpufreq_data {
  34         void __iomem *base;
  35         struct resource *res;
  36         const struct qcom_cpufreq_soc_data *soc_data;
  37 };
  38
  39 static unsigned long cpu_hw_rate, xo_rate;
  40 static bool icc_scaling_enabled;
  41
  42 static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
  43                                unsigned long freq_khz)
  44 {
  45         unsigned long freq_hz = freq_khz * 1000;
  46         struct dev_pm_opp *opp;
  47         struct device *dev;
  48         int ret;
  49
  50         dev = get_cpu_device(policy->cpu);
  51         if (!dev)
  52                 return -ENODEV;
  53
  54         opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
  55         if (IS_ERR(opp))
  56                 return PTR_ERR(opp);
  57
  58         ret = dev_pm_opp_set_opp(dev, opp);
  59         dev_pm_opp_put(opp);
  60         return ret;
  61 }
  62
  63 static int qcom_cpufreq_update_opp(struct device *cpu_dev,
  64                                    unsigned long freq_khz,
  65                                    unsigned long volt)
  66 {
  67         unsigned long freq_hz = freq_khz * 1000;
  68         int ret;
  69
  70         /* Skip voltage update if the opp table is not available */
  71         if (!icc_scaling_enabled)
  72                 return dev_pm_opp_add(cpu_dev, freq_hz, volt);
  73
  74         ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
  75         if (ret) {
  76                 dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
  77                 return ret;
  78         }
  79
  80         return dev_pm_opp_enable(cpu_dev, freq_hz);
  81 }
  82
  83 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
  84                                         unsigned int index)
  85 {
  86         struct qcom_cpufreq_data *data = policy->driver_data;
  87         const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
  88         unsigned long freq = policy->freq_table[index].frequency;
  89
  90         writel_relaxed(index, data->base + soc_data->reg_perf_state);
  91
  92         if (icc_scaling_enabled)
  93                 qcom_cpufreq_set_bw(policy, freq);
  94
  95         return 0;
  96 }
  97
  98 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
  99 {
 100         struct qcom_cpufreq_data *data;
 101         const struct qcom_cpufreq_soc_data *soc_data;
 102         struct cpufreq_policy *policy;
 103         unsigned int index;
 104
 105         policy = cpufreq_cpu_get_raw(cpu);
 106         if (!policy)
 107                 return 0;
 108
 109         data = policy->driver_data;
 110         soc_data = data->soc_data;
 111
 112         index = readl_relaxed(data->base + soc_data->reg_perf_state);
 113         index = min(index, LUT_MAX_ENTRIES - 1);
 114
 115         return policy->freq_table[index].frequency;
 116 }
 117
 118 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 119                                                 unsigned int target_freq)
 120 {
 121         struct qcom_cpufreq_data *data = policy->driver_data;
 122         const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
 123         unsigned int index;
 124
 125         index = policy->cached_resolved_idx;
 126         writel_relaxed(index, data->base + soc_data->reg_perf_state);
 127
 128         return policy->freq_table[index].frequency;
 129 }
 130
 131 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
 132                                     struct cpufreq_policy *policy)
 133 {
 134         u32 data, src, lval, i, core_count, prev_freq = 0, freq;
 135         u32 volt;
 136         struct cpufreq_frequency_table  *table;
 137         struct dev_pm_opp *opp;
 138         unsigned long rate;
 139         int ret;
 140         struct qcom_cpufreq_data *drv_data = policy->driver_data;
 141         const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;
 142
 143         table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
 144         if (!table)
 145                 return -ENOMEM;
 146
 147         ret = dev_pm_opp_of_add_table(cpu_dev);
 148         if (!ret) {
 149                 /* Disable all opps and cross-validate against LUT later */
 150                 icc_scaling_enabled = true;
 151                 for (rate = 0; ; rate++) {
 152                         opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
 153                         if (IS_ERR(opp))
 154                                 break;
 155
 156                         dev_pm_opp_put(opp);
 157                         dev_pm_opp_disable(cpu_dev, rate);
 158                 }
 159         } else if (ret != -ENODEV) {
 160                 dev_err(cpu_dev, "Invalid opp table in device tree\n");
 161                 return ret;
 162         } else {
 163                 policy->fast_switch_possible = true;
 164                 icc_scaling_enabled = false;
 165         }
 166
 167         for (i = 0; i < LUT_MAX_ENTRIES; i++) {
 168                 data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
 169                                       i * soc_data->lut_row_size);
 170                 src = FIELD_GET(LUT_SRC, data);
 171                 lval = FIELD_GET(LUT_L_VAL, data);
 172                 core_count = FIELD_GET(LUT_CORE_COUNT, data);
 173
 174                 data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
 175                                       i * soc_data->lut_row_size);
 176                 volt = FIELD_GET(LUT_VOLT, data) * 1000;
 177
 178                 if (src)
 179                         freq = xo_rate * lval / 1000;
 180                 else
 181                         freq = cpu_hw_rate / 1000;
 182
 183                 if (freq != prev_freq && core_count != LUT_TURBO_IND) {
 184                         if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
 185                                 table[i].frequency = freq;
 186                                 dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
 187                                 freq, core_count);
 188                         } else {
 189                                 dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
 190                                 table[i].frequency = CPUFREQ_ENTRY_INVALID;
 191                         }
 192
 193                 } else if (core_count == LUT_TURBO_IND) {
 194                         table[i].frequency = CPUFREQ_ENTRY_INVALID;
 195                 }
 196
 197                 /*
 198                  * Two of the same frequencies with the same core counts means
 199                  * end of table
 200                  */
 201                 if (i > 0 && prev_freq == freq) {
 202                         struct cpufreq_frequency_table *prev = &table[i - 1];
 203
 204                         /*
 205                          * Only treat the last frequency that might be a boost
 206                          * as the boost frequency
 207                          */
 208                         if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
 209                                 if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
 210                                         prev->frequency = prev_freq;
 211                                         prev->flags = CPUFREQ_BOOST_FREQ;
 212                                 } else {
 213                                         dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
 214                                                  freq);
 215                                 }
 216                         }
 217
 218                         break;
 219                 }
 220
 221                 prev_freq = freq;
 222         }
 223
 224         table[i].frequency = CPUFREQ_TABLE_END;
 225         policy->freq_table = table;
 226         dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
 227
 228         return 0;
 229 }
 230
 231 static void qcom_get_related_cpus(int index, struct cpumask *m)
 232 {
 233         struct device_node *cpu_np;
 234         struct of_phandle_args args;
 235         int cpu, ret;
 236
 237         for_each_possible_cpu(cpu) {
 238                 cpu_np = of_cpu_device_node_get(cpu);
 239                 if (!cpu_np)
 240                         continue;
 241
 242                 ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 243                                                  "#freq-domain-cells", 0,
 244                                                  &args);
 245                 of_node_put(cpu_np);
 246                 if (ret < 0)
 247                         continue;
 248
 249                 if (index == args.args[0])
 250                         cpumask_set_cpu(cpu, m);
 251         }
 252 }
 253
 254 static const struct qcom_cpufreq_soc_data qcom_soc_data = {
 255         .reg_enable = 0x0,
 256         .reg_freq_lut = 0x110,
 257         .reg_volt_lut = 0x114,
 258         .reg_perf_state = 0x920,
 259         .lut_row_size = 32,
 260 };
 261
 262 static const struct qcom_cpufreq_soc_data epss_soc_data = {
 263         .reg_enable = 0x0,
 264         .reg_freq_lut = 0x100,
 265         .reg_volt_lut = 0x200,
 266         .reg_perf_state = 0x320,
 267         .lut_row_size = 4,
 268 };
 269
 270 static const struct of_device_id qcom_cpufreq_hw_match[] = {
 271         { .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
 272         { .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
 273         {}
 274 };
 275 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
 276
 277 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 278 {
 279         struct platform_device *pdev = cpufreq_get_driver_data();
 280         struct device *dev = &pdev->dev;
 281         struct of_phandle_args args;
 282         struct device_node *cpu_np;
 283         struct device *cpu_dev;
 284         struct resource *res;
 285         void __iomem *base;
 286         struct qcom_cpufreq_data *data;
 287         int ret, index;
 288
 289         cpu_dev = get_cpu_device(policy->cpu);
 290         if (!cpu_dev) {
 291                 pr_err("%s: failed to get cpu%d device\n", __func__,
 292                        policy->cpu);
 293                 return -ENODEV;
 294         }
 295
 296         cpu_np = of_cpu_device_node_get(policy->cpu);
 297         if (!cpu_np)
 298                 return -EINVAL;
 299
 300         ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 301                                          "#freq-domain-cells", 0, &args);
 302         of_node_put(cpu_np);
 303         if (ret)
 304                 return ret;
 305
 306         index = args.args[0];
 307
 308         res = platform_get_resource(pdev, IORESOURCE_MEM, index);
 309         if (!res) {
 310                 dev_err(dev, "failed to get mem resource %d\n", index);
 311                 return -ENODEV;
 312         }
 313
 314         if (!request_mem_region(res->start, resource_size(res), res->name)) {
 315                 dev_err(dev, "failed to request resource %pR\n", res);
 316                 return -EBUSY;
 317         }
 318
 319         base = ioremap(res->start, resource_size(res));
 320         if (IS_ERR(base)) {
 321                 dev_err(dev, "failed to map resource %pR\n", res);
 322                 ret = PTR_ERR(base);
 323                 goto release_region;
 324         }
 325
 326         data = kzalloc(sizeof(*data), GFP_KERNEL);
 327         if (!data) {
 328                 ret = -ENOMEM;
 329                 goto unmap_base;
 330         }
 331
 332         data->soc_data = of_device_get_match_data(&pdev->dev);
 333         data->base = base;
 334         data->res = res;
 335
 336         /* HW should be in enabled state to proceed */
 337         if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
 338                 dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
 339                 ret = -ENODEV;
 340                 goto error;
 341         }
 342
 343         qcom_get_related_cpus(index, policy->cpus);
 344         if (!cpumask_weight(policy->cpus)) {
 345                 dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
 346                 ret = -ENOENT;
 347                 goto error;
 348         }
 349
 350         policy->driver_data = data;
 351
 352         ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
 353         if (ret) {
 354                 dev_err(dev, "Domain-%d failed to read LUT\n", index);
 355                 goto error;
 356         }
 357
 358         ret = dev_pm_opp_get_opp_count(cpu_dev);
 359         if (ret <= 0) {
 360                 dev_err(cpu_dev, "Failed to add OPPs\n");
 361                 ret = -ENODEV;
 362                 goto error;
 363         }
 364
 365         dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
 366
 367         if (policy_has_boost_freq(policy)) {
 368                 ret = cpufreq_enable_boost_support();
 369                 if (ret)
 370                         dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
 371         }
 372
 373         return 0;
 374 error:
 375         kfree(data);
 376 unmap_base:
 377         iounmap(data->base);
 378 release_region:
 379         release_mem_region(res->start, resource_size(res));
 380         return ret;
 381 }
 382
 383 static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 384 {
 385         struct device *cpu_dev = get_cpu_device(policy->cpu);
 386         struct qcom_cpufreq_data *data = policy->driver_data;
 387         struct resource *res = data->res;
 388         void __iomem *base = data->base;
 389
 390         dev_pm_opp_remove_all_dynamic(cpu_dev);
 391         dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
 392         kfree(policy->freq_table);
 393         kfree(data);
 394         iounmap(base);
 395         release_mem_region(res->start, resource_size(res));
 396
 397         return 0;
 398 }
 399
 400 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
 401         &cpufreq_freq_attr_scaling_available_freqs,
 402         &cpufreq_freq_attr_scaling_boost_freqs,
 403         NULL
 404 };
 405
 406 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
 407         .flags          = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
 408                           CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
 409                           CPUFREQ_IS_COOLING_DEV,
 410         .verify         = cpufreq_generic_frequency_table_verify,
 411         .target_index   = qcom_cpufreq_hw_target_index,
 412         .get            = qcom_cpufreq_hw_get,
 413         .init           = qcom_cpufreq_hw_cpu_init,
 414         .exit           = qcom_cpufreq_hw_cpu_exit,
 415         .fast_switch    = qcom_cpufreq_hw_fast_switch,
 416         .name           = "qcom-cpufreq-hw",
 417         .attr           = qcom_cpufreq_hw_attr,
 418 };
 419
 420 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
 421 {
 422         struct device *cpu_dev;
 423         struct clk *clk;
 424         int ret;
 425
 426         clk = clk_get(&pdev->dev, "xo");
 427         if (IS_ERR(clk))
 428                 return PTR_ERR(clk);
 429
 430         xo_rate = clk_get_rate(clk);
 431         clk_put(clk);
 432
 433         clk = clk_get(&pdev->dev, "alternate");
 434         if (IS_ERR(clk))
 435                 return PTR_ERR(clk);
 436
 437         cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
 438         clk_put(clk);
 439
 440         cpufreq_qcom_hw_driver.driver_data = pdev;
 441
 442         /* Check for optional interconnect paths on CPU0 */
 443         cpu_dev = get_cpu_device(0);
 444         if (!cpu_dev)
 445                 return -EPROBE_DEFER;
 446
 447         ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
 448         if (ret)
 449                 return ret;
 450
 451         ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
 452         if (ret)
 453                 dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
 454         else
 455                 dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
 456
 457         return ret;
 458 }
 459
 460 static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
 461 {
 462         return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
 463 }
 464
 465 static struct platform_driver qcom_cpufreq_hw_driver = {
 466         .probe = qcom_cpufreq_hw_driver_probe,
 467         .remove = qcom_cpufreq_hw_driver_remove,
 468         .driver = {
 469                 .name = "qcom-cpufreq-hw",
 470                 .of_match_table = qcom_cpufreq_hw_match,
 471         },
 472 };
 473
 474 static int __init qcom_cpufreq_hw_init(void)
 475 {
 476         return platform_driver_register(&qcom_cpufreq_hw_driver);
 477 }
 478 postcore_initcall(qcom_cpufreq_hw_init);
 479
 480 static void __exit qcom_cpufreq_hw_exit(void)
 481 {
 482         platform_driver_unregister(&qcom_cpufreq_hw_driver);
 483 }
 484 module_exit(qcom_cpufreq_hw_exit);
 485
 486 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
 487 MODULE_LICENSE("GPL v2");