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