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/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/of_address.h>
  12 #include <linux/of_platform.h>
  13 #include <linux/pm_opp.h>
  14 #include <linux/slab.h>
  15
  16 #define LUT_MAX_ENTRIES                 40U
  17 #define LUT_SRC                         GENMASK(31, 30)
  18 #define LUT_L_VAL                       GENMASK(7, 0)
  19 #define LUT_CORE_COUNT                  GENMASK(18, 16)
  20 #define LUT_VOLT                        GENMASK(11, 0)
  21 #define LUT_ROW_SIZE                    32
  22 #define CLK_HW_DIV                      2
  23
  24 /* Register offsets */
  25 #define REG_ENABLE                      0x0
  26 #define REG_FREQ_LUT                    0x110
  27 #define REG_VOLT_LUT                    0x114
  28 #define REG_PERF_STATE                  0x920
  29
  30 static unsigned long cpu_hw_rate, xo_rate;
  31 static struct platform_device *global_pdev;
  32
  33 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
  34                                         unsigned int index)
  35 {
  36         void __iomem *perf_state_reg = policy->driver_data;
  37
  38         writel_relaxed(index, perf_state_reg);
  39
  40         return 0;
  41 }
  42
  43 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
  44 {
  45         void __iomem *perf_state_reg;
  46         struct cpufreq_policy *policy;
  47         unsigned int index;
  48
  49         policy = cpufreq_cpu_get_raw(cpu);
  50         if (!policy)
  51                 return 0;
  52
  53         perf_state_reg = policy->driver_data;
  54
  55         index = readl_relaxed(perf_state_reg);
  56         index = min(index, LUT_MAX_ENTRIES - 1);
  57
  58         return policy->freq_table[index].frequency;
  59 }
  60
  61 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
  62                                                 unsigned int target_freq)
  63 {
  64         void __iomem *perf_state_reg = policy->driver_data;
  65         int index;
  66
  67         index = policy->cached_resolved_idx;
  68         if (index < 0)
  69                 return 0;
  70
  71         writel_relaxed(index, perf_state_reg);
  72
  73         return policy->freq_table[index].frequency;
  74 }
  75
  76 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
  77                                     struct cpufreq_policy *policy,
  78                                     void __iomem *base)
  79 {
  80         u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
  81         u32 volt;
  82         unsigned int max_cores = cpumask_weight(policy->cpus);
  83         struct cpufreq_frequency_table  *table;
  84
  85         table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
  86         if (!table)
  87                 return -ENOMEM;
  88
  89         for (i = 0; i < LUT_MAX_ENTRIES; i++) {
  90                 data = readl_relaxed(base + REG_FREQ_LUT +
  91                                       i * LUT_ROW_SIZE);
  92                 src = FIELD_GET(LUT_SRC, data);
  93                 lval = FIELD_GET(LUT_L_VAL, data);
  94                 core_count = FIELD_GET(LUT_CORE_COUNT, data);
  95
  96                 data = readl_relaxed(base + REG_VOLT_LUT +
  97                                       i * LUT_ROW_SIZE);
  98                 volt = FIELD_GET(LUT_VOLT, data) * 1000;
  99
 100                 if (src)
 101                         freq = xo_rate * lval / 1000;
 102                 else
 103                         freq = cpu_hw_rate / 1000;
 104
 105                 if (freq != prev_freq && core_count == max_cores) {
 106                         table[i].frequency = freq;
 107                         dev_pm_opp_add(cpu_dev, freq * 1000, volt);
 108                         dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
 109                                 freq, core_count);
 110                 } else {
 111                         table[i].frequency = CPUFREQ_ENTRY_INVALID;
 112                 }
 113
 114                 /*
 115                  * Two of the same frequencies with the same core counts means
 116                  * end of table
 117                  */
 118                 if (i > 0 && prev_freq == freq && prev_cc == core_count) {
 119                         struct cpufreq_frequency_table *prev = &table[i - 1];
 120
 121                         /*
 122                          * Only treat the last frequency that might be a boost
 123                          * as the boost frequency
 124                          */
 125                         if (prev_cc != max_cores) {
 126                                 prev->frequency = prev_freq;
 127                                 prev->flags = CPUFREQ_BOOST_FREQ;
 128                                 dev_pm_opp_add(cpu_dev, prev_freq * 1000, volt);
 129                         }
 130
 131                         break;
 132                 }
 133
 134                 prev_cc = core_count;
 135                 prev_freq = freq;
 136         }
 137
 138         table[i].frequency = CPUFREQ_TABLE_END;
 139         policy->freq_table = table;
 140         dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
 141
 142         return 0;
 143 }
 144
 145 static void qcom_get_related_cpus(int index, struct cpumask *m)
 146 {
 147         struct device_node *cpu_np;
 148         struct of_phandle_args args;
 149         int cpu, ret;
 150
 151         for_each_possible_cpu(cpu) {
 152                 cpu_np = of_cpu_device_node_get(cpu);
 153                 if (!cpu_np)
 154                         continue;
 155
 156                 ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 157                                                  "#freq-domain-cells", 0,
 158                                                  &args);
 159                 of_node_put(cpu_np);
 160                 if (ret < 0)
 161                         continue;
 162
 163                 if (index == args.args[0])
 164                         cpumask_set_cpu(cpu, m);
 165         }
 166 }
 167
 168 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 169 {
 170         struct device *dev = &global_pdev->dev;
 171         struct of_phandle_args args;
 172         struct device_node *cpu_np;
 173         struct device *cpu_dev;
 174         struct resource *res;
 175         void __iomem *base;
 176         int ret, index;
 177
 178         cpu_dev = get_cpu_device(policy->cpu);
 179         if (!cpu_dev) {
 180                 pr_err("%s: failed to get cpu%d device\n", __func__,
 181                        policy->cpu);
 182                 return -ENODEV;
 183         }
 184
 185         cpu_np = of_cpu_device_node_get(policy->cpu);
 186         if (!cpu_np)
 187                 return -EINVAL;
 188
 189         ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 190                                          "#freq-domain-cells", 0, &args);
 191         of_node_put(cpu_np);
 192         if (ret)
 193                 return ret;
 194
 195         index = args.args[0];
 196
 197         res = platform_get_resource(global_pdev, IORESOURCE_MEM, index);
 198         if (!res)
 199                 return -ENODEV;
 200
 201         base = devm_ioremap(dev, res->start, resource_size(res));
 202         if (!base)
 203                 return -ENOMEM;
 204
 205         /* HW should be in enabled state to proceed */
 206         if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) {
 207                 dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
 208                 ret = -ENODEV;
 209                 goto error;
 210         }
 211
 212         qcom_get_related_cpus(index, policy->cpus);
 213         if (!cpumask_weight(policy->cpus)) {
 214                 dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
 215                 ret = -ENOENT;
 216                 goto error;
 217         }
 218
 219         policy->driver_data = base + REG_PERF_STATE;
 220
 221         ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy, base);
 222         if (ret) {
 223                 dev_err(dev, "Domain-%d failed to read LUT\n", index);
 224                 goto error;
 225         }
 226
 227         ret = dev_pm_opp_get_opp_count(cpu_dev);
 228         if (ret <= 0) {
 229                 dev_err(cpu_dev, "Failed to add OPPs\n");
 230                 ret = -ENODEV;
 231                 goto error;
 232         }
 233
 234         dev_pm_opp_of_register_em(policy->cpus);
 235
 236         policy->fast_switch_possible = true;
 237
 238         return 0;
 239 error:
 240         devm_iounmap(dev, base);
 241         return ret;
 242 }
 243
 244 static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 245 {
 246         struct device *cpu_dev = get_cpu_device(policy->cpu);
 247         void __iomem *base = policy->driver_data - REG_PERF_STATE;
 248
 249         dev_pm_opp_remove_all_dynamic(cpu_dev);
 250         kfree(policy->freq_table);
 251         devm_iounmap(&global_pdev->dev, base);
 252
 253         return 0;
 254 }
 255
 256 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
 257         &cpufreq_freq_attr_scaling_available_freqs,
 258         &cpufreq_freq_attr_scaling_boost_freqs,
 259         NULL
 260 };
 261
 262 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
 263         .flags          = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
 264                           CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
 265                           CPUFREQ_IS_COOLING_DEV,
 266         .verify         = cpufreq_generic_frequency_table_verify,
 267         .target_index   = qcom_cpufreq_hw_target_index,
 268         .get            = qcom_cpufreq_hw_get,
 269         .init           = qcom_cpufreq_hw_cpu_init,
 270         .exit           = qcom_cpufreq_hw_cpu_exit,
 271         .fast_switch    = qcom_cpufreq_hw_fast_switch,
 272         .name           = "qcom-cpufreq-hw",
 273         .attr           = qcom_cpufreq_hw_attr,
 274 };
 275
 276 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
 277 {
 278         struct clk *clk;
 279         int ret;
 280
 281         clk = clk_get(&pdev->dev, "xo");
 282         if (IS_ERR(clk))
 283                 return PTR_ERR(clk);
 284
 285         xo_rate = clk_get_rate(clk);
 286         clk_put(clk);
 287
 288         clk = clk_get(&pdev->dev, "alternate");
 289         if (IS_ERR(clk))
 290                 return PTR_ERR(clk);
 291
 292         cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
 293         clk_put(clk);
 294
 295         global_pdev = pdev;
 296
 297         ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
 298         if (ret)
 299                 dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
 300         else
 301                 dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
 302
 303         return ret;
 304 }
 305
 306 static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
 307 {
 308         return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
 309 }
 310
 311 static const struct of_device_id qcom_cpufreq_hw_match[] = {
 312         { .compatible = "qcom,cpufreq-hw" },
 313         {}
 314 };
 315 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
 316
 317 static struct platform_driver qcom_cpufreq_hw_driver = {
 318         .probe = qcom_cpufreq_hw_driver_probe,
 319         .remove = qcom_cpufreq_hw_driver_remove,
 320         .driver = {
 321                 .name = "qcom-cpufreq-hw",
 322                 .of_match_table = qcom_cpufreq_hw_match,
 323         },
 324 };
 325
 326 static int __init qcom_cpufreq_hw_init(void)
 327 {
 328         return platform_driver_register(&qcom_cpufreq_hw_driver);
 329 }
 330 device_initcall(qcom_cpufreq_hw_init);
 331
 332 static void __exit qcom_cpufreq_hw_exit(void)
 333 {
 334         platform_driver_unregister(&qcom_cpufreq_hw_driver);
 335 }
 336 module_exit(qcom_cpufreq_hw_exit);
 337
 338 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
 339 MODULE_LICENSE("GPL v2");