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