drivers/cpufreq/mediatek-cpufreq-hw.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2020 MediaTek Inc.
   4  */
   5
   6 #include <linux/bitfield.h>
   7 #include <linux/cpufreq.h>
   8 #include <linux/energy_model.h>
   9 #include <linux/init.h>
  10 #include <linux/iopoll.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regulator/consumer.h>
  17 #include <linux/slab.h>
  18
  19 #define LUT_MAX_ENTRIES                 32U
  20 #define LUT_FREQ                        GENMASK(11, 0)
  21 #define LUT_ROW_SIZE                    0x4
  22 #define CPUFREQ_HW_STATUS               BIT(0)
  23 #define SVS_HW_STATUS                   BIT(1)
  24 #define POLL_USEC                       1000
  25 #define TIMEOUT_USEC                    300000
  26
  27 enum {
  28         REG_FREQ_LUT_TABLE,
  29         REG_FREQ_ENABLE,
  30         REG_FREQ_PERF_STATE,
  31         REG_FREQ_HW_STATE,
  32         REG_EM_POWER_TBL,
  33         REG_FREQ_LATENCY,
  34
  35         REG_ARRAY_SIZE,
  36 };
  37
  38 struct mtk_cpufreq_data {
  39         struct cpufreq_frequency_table *table;
  40         void __iomem *reg_bases[REG_ARRAY_SIZE];
  41         struct resource *res;
  42         void __iomem *base;
  43         int nr_opp;
  44 };
  45
  46 static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = {
  47         [REG_FREQ_LUT_TABLE]    = 0x0,
  48         [REG_FREQ_ENABLE]       = 0x84,
  49         [REG_FREQ_PERF_STATE]   = 0x88,
  50         [REG_FREQ_HW_STATE]     = 0x8c,
  51         [REG_EM_POWER_TBL]      = 0x90,
  52         [REG_FREQ_LATENCY]      = 0x110,
  53 };
  54
  55 static int __maybe_unused
  56 mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
  57                           unsigned long *KHz)
  58 {
  59         struct mtk_cpufreq_data *data;
  60         struct cpufreq_policy *policy;
  61         int i;
  62
  63         policy = cpufreq_cpu_get_raw(cpu_dev->id);
  64         if (!policy)
  65                 return 0;
  66
  67         data = policy->driver_data;
  68
  69         for (i = 0; i < data->nr_opp; i++) {
  70                 if (data->table[i].frequency < *KHz)
  71                         break;
  72         }
  73         i--;
  74
  75         *KHz = data->table[i].frequency;
  76         /* Provide micro-Watts value to the Energy Model */
  77         *uW = readl_relaxed(data->reg_bases[REG_EM_POWER_TBL] +
  78                             i * LUT_ROW_SIZE);
  79
  80         return 0;
  81 }
  82
  83 static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
  84                                        unsigned int index)
  85 {
  86         struct mtk_cpufreq_data *data = policy->driver_data;
  87
  88         writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
  89
  90         return 0;
  91 }
  92
  93 static unsigned int mtk_cpufreq_hw_get(unsigned int cpu)
  94 {
  95         struct mtk_cpufreq_data *data;
  96         struct cpufreq_policy *policy;
  97         unsigned int index;
  98
  99         policy = cpufreq_cpu_get_raw(cpu);
 100         if (!policy)
 101                 return 0;
 102
 103         data = policy->driver_data;
 104
 105         index = readl_relaxed(data->reg_bases[REG_FREQ_PERF_STATE]);
 106         index = min(index, LUT_MAX_ENTRIES - 1);
 107
 108         return data->table[index].frequency;
 109 }
 110
 111 static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 112                                                unsigned int target_freq)
 113 {
 114         struct mtk_cpufreq_data *data = policy->driver_data;
 115         unsigned int index;
 116
 117         index = cpufreq_table_find_index_dl(policy, target_freq, false);
 118
 119         writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
 120
 121         return policy->freq_table[index].frequency;
 122 }
 123
 124 static int mtk_cpu_create_freq_table(struct platform_device *pdev,
 125                                      struct mtk_cpufreq_data *data)
 126 {
 127         struct device *dev = &pdev->dev;
 128         u32 temp, i, freq, prev_freq = 0;
 129         void __iomem *base_table;
 130
 131         data->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
 132                                    sizeof(*data->table), GFP_KERNEL);
 133         if (!data->table)
 134                 return -ENOMEM;
 135
 136         base_table = data->reg_bases[REG_FREQ_LUT_TABLE];
 137
 138         for (i = 0; i < LUT_MAX_ENTRIES; i++) {
 139                 temp = readl_relaxed(base_table + (i * LUT_ROW_SIZE));
 140                 freq = FIELD_GET(LUT_FREQ, temp) * 1000;
 141
 142                 if (freq == prev_freq)
 143                         break;
 144
 145                 data->table[i].frequency = freq;
 146
 147                 dev_dbg(dev, "index=%d freq=%d\n", i, data->table[i].frequency);
 148
 149                 prev_freq = freq;
 150         }
 151
 152         data->table[i].frequency = CPUFREQ_TABLE_END;
 153         data->nr_opp = i;
 154
 155         return 0;
 156 }
 157
 158 static int mtk_cpu_resources_init(struct platform_device *pdev,
 159                                   struct cpufreq_policy *policy,
 160                                   const u16 *offsets)
 161 {
 162         struct mtk_cpufreq_data *data;
 163         struct device *dev = &pdev->dev;
 164         struct resource *res;
 165         struct of_phandle_args args;
 166         void __iomem *base;
 167         int ret, i;
 168         int index;
 169
 170         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 171         if (!data)
 172                 return -ENOMEM;
 173
 174         ret = of_perf_domain_get_sharing_cpumask(policy->cpu, "performance-domains",
 175                                                  "#performance-domain-cells",
 176                                                  policy->cpus, &args);
 177         if (ret < 0)
 178                 return ret;
 179
 180         index = args.args[0];
 181         of_node_put(args.np);
 182
 183         res = platform_get_resource(pdev, IORESOURCE_MEM, index);
 184         if (!res) {
 185                 dev_err(dev, "failed to get mem resource %d\n", index);
 186                 return -ENODEV;
 187         }
 188
 189         if (!request_mem_region(res->start, resource_size(res), res->name)) {
 190                 dev_err(dev, "failed to request resource %pR\n", res);
 191                 return -EBUSY;
 192         }
 193
 194         base = ioremap(res->start, resource_size(res));
 195         if (!base) {
 196                 dev_err(dev, "failed to map resource %pR\n", res);
 197                 ret = -ENOMEM;
 198                 goto release_region;
 199         }
 200
 201         data->base = base;
 202         data->res = res;
 203
 204         for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++)
 205                 data->reg_bases[i] = base + offsets[i];
 206
 207         ret = mtk_cpu_create_freq_table(pdev, data);
 208         if (ret) {
 209                 dev_info(dev, "Domain-%d failed to create freq table\n", index);
 210                 return ret;
 211         }
 212
 213         policy->freq_table = data->table;
 214         policy->driver_data = data;
 215
 216         return 0;
 217 release_region:
 218         release_mem_region(res->start, resource_size(res));
 219         return ret;
 220 }
 221
 222 static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 223 {
 224         struct platform_device *pdev = cpufreq_get_driver_data();
 225         int sig, pwr_hw = CPUFREQ_HW_STATUS | SVS_HW_STATUS;
 226         struct mtk_cpufreq_data *data;
 227         unsigned int latency;
 228         int ret;
 229
 230         /* Get the bases of cpufreq for domains */
 231         ret = mtk_cpu_resources_init(pdev, policy, platform_get_drvdata(pdev));
 232         if (ret) {
 233                 dev_info(&pdev->dev, "CPUFreq resource init failed\n");
 234                 return ret;
 235         }
 236
 237         data = policy->driver_data;
 238
 239         latency = readl_relaxed(data->reg_bases[REG_FREQ_LATENCY]) * 1000;
 240         if (!latency)
 241                 latency = CPUFREQ_ETERNAL;
 242
 243         policy->cpuinfo.transition_latency = latency;
 244         policy->fast_switch_possible = true;
 245
 246         /* HW should be in enabled state to proceed now */
 247         writel_relaxed(0x1, data->reg_bases[REG_FREQ_ENABLE]);
 248         if (readl_poll_timeout(data->reg_bases[REG_FREQ_HW_STATE], sig,
 249                                (sig & pwr_hw) == pwr_hw, POLL_USEC,
 250                                TIMEOUT_USEC)) {
 251                 if (!(sig & CPUFREQ_HW_STATUS)) {
 252                         pr_info("cpufreq hardware of CPU%d is not enabled\n",
 253                                 policy->cpu);
 254                         return -ENODEV;
 255                 }
 256
 257                 pr_info("SVS of CPU%d is not enabled\n", policy->cpu);
 258         }
 259
 260         return 0;
 261 }
 262
 263 static int mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 264 {
 265         struct mtk_cpufreq_data *data = policy->driver_data;
 266         struct resource *res = data->res;
 267         void __iomem *base = data->base;
 268
 269         /* HW should be in paused state now */
 270         writel_relaxed(0x0, data->reg_bases[REG_FREQ_ENABLE]);
 271         iounmap(base);
 272         release_mem_region(res->start, resource_size(res));
 273
 274         return 0;
 275 }
 276
 277 static void mtk_cpufreq_register_em(struct cpufreq_policy *policy)
 278 {
 279         struct em_data_callback em_cb = EM_DATA_CB(mtk_cpufreq_get_cpu_power);
 280         struct mtk_cpufreq_data *data = policy->driver_data;
 281
 282         em_dev_register_perf_domain(get_cpu_device(policy->cpu), data->nr_opp,
 283                                     &em_cb, policy->cpus, true);
 284 }
 285
 286 static struct cpufreq_driver cpufreq_mtk_hw_driver = {
 287         .flags          = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
 288                           CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
 289                           CPUFREQ_IS_COOLING_DEV,
 290         .verify         = cpufreq_generic_frequency_table_verify,
 291         .target_index   = mtk_cpufreq_hw_target_index,
 292         .get            = mtk_cpufreq_hw_get,
 293         .init           = mtk_cpufreq_hw_cpu_init,
 294         .exit           = mtk_cpufreq_hw_cpu_exit,
 295         .register_em    = mtk_cpufreq_register_em,
 296         .fast_switch    = mtk_cpufreq_hw_fast_switch,
 297         .name           = "mtk-cpufreq-hw",
 298         .attr           = cpufreq_generic_attr,
 299 };
 300
 301 static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
 302 {
 303         const void *data;
 304         int ret, cpu;
 305         struct device *cpu_dev;
 306         struct regulator *cpu_reg;
 307
 308         /* Make sure that all CPU supplies are available before proceeding. */
 309         for_each_possible_cpu(cpu) {
 310                 cpu_dev = get_cpu_device(cpu);
 311                 if (!cpu_dev)
 312                         return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
 313                                              "Failed to get cpu%d device\n", cpu);
 314
 315                 cpu_reg = devm_regulator_get(cpu_dev, "cpu");
 316                 if (IS_ERR(cpu_reg))
 317                         return dev_err_probe(&pdev->dev, PTR_ERR(cpu_reg),
 318                                              "CPU%d regulator get failed\n", cpu);
 319         }
 320
 321
 322         data = of_device_get_match_data(&pdev->dev);
 323         if (!data)
 324                 return -EINVAL;
 325
 326         platform_set_drvdata(pdev, (void *) data);
 327         cpufreq_mtk_hw_driver.driver_data = pdev;
 328
 329         ret = cpufreq_register_driver(&cpufreq_mtk_hw_driver);
 330         if (ret)
 331                 dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
 332
 333         return ret;
 334 }
 335
 336 static void mtk_cpufreq_hw_driver_remove(struct platform_device *pdev)
 337 {
 338         cpufreq_unregister_driver(&cpufreq_mtk_hw_driver);
 339 }
 340
 341 static const struct of_device_id mtk_cpufreq_hw_match[] = {
 342         { .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_offsets },
 343         {}
 344 };
 345 MODULE_DEVICE_TABLE(of, mtk_cpufreq_hw_match);
 346
 347 static struct platform_driver mtk_cpufreq_hw_driver = {
 348         .probe = mtk_cpufreq_hw_driver_probe,
 349         .remove_new = mtk_cpufreq_hw_driver_remove,
 350         .driver = {
 351                 .name = "mtk-cpufreq-hw",
 352                 .of_match_table = mtk_cpufreq_hw_match,
 353         },
 354 };
 355 module_platform_driver(mtk_cpufreq_hw_driver);
 356
 357 MODULE_AUTHOR("Hector Yuan <hector.yuan@mediatek.com>");
 358 MODULE_DESCRIPTION("Mediatek cpufreq-hw driver");
 359 MODULE_LICENSE("GPL v2");