1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Freescale Semiconductor, Inc. 4 * 5 * Copyright (C) 2014 Linaro. 6 * Viresh Kumar <viresh.kumar@linaro.org> 7 */ 8 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/clk.h> 12 #include <linux/cpu.h> 13 #include <linux/cpufreq.h> 14 #include <linux/cpumask.h> 15 #include <linux/err.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/pm_opp.h> 19 #include <linux/platform_device.h> 20 #include <linux/regulator/consumer.h> 21 #include <linux/slab.h> 22 #include <linux/thermal.h> 23 24 #include "cpufreq-dt.h" 25 26 struct private_data { 27 struct opp_table *opp_table; 28 struct device *cpu_dev; 29 const char *reg_name; 30 bool have_static_opps; 31 }; 32 33 static struct freq_attr *cpufreq_dt_attr[] = { 34 &cpufreq_freq_attr_scaling_available_freqs, 35 NULL, /* Extra space for boost-attr if required */ 36 NULL, 37 }; 38 39 static int set_target(struct cpufreq_policy *policy, unsigned int index) 40 { 41 struct private_data *priv = policy->driver_data; 42 unsigned long freq = policy->freq_table[index].frequency; 43 int ret; 44 45 ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000); 46 47 if (!ret) { 48 arch_set_freq_scale(policy->related_cpus, freq, 49 policy->cpuinfo.max_freq); 50 } 51 52 return ret; 53 } 54 55 /* 56 * An earlier version of opp-v1 bindings used to name the regulator 57 * "cpu0-supply", we still need to handle that for backwards compatibility. 58 */ 59 static const char *find_supply_name(struct device *dev) 60 { 61 struct device_node *np; 62 struct property *pp; 63 int cpu = dev->id; 64 const char *name = NULL; 65 66 np = of_node_get(dev->of_node); 67 68 /* This must be valid for sure */ 69 if (WARN_ON(!np)) 70 return NULL; 71 72 /* Try "cpu0" for older DTs */ 73 if (!cpu) { 74 pp = of_find_property(np, "cpu0-supply", NULL); 75 if (pp) { 76 name = "cpu0"; 77 goto node_put; 78 } 79 } 80 81 pp = of_find_property(np, "cpu-supply", NULL); 82 if (pp) { 83 name = "cpu"; 84 goto node_put; 85 } 86 87 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 88 node_put: 89 of_node_put(np); 90 return name; 91 } 92 93 static int resources_available(void) 94 { 95 struct device *cpu_dev; 96 struct regulator *cpu_reg; 97 struct clk *cpu_clk; 98 int ret = 0; 99 const char *name; 100 101 cpu_dev = get_cpu_device(0); 102 if (!cpu_dev) { 103 pr_err("failed to get cpu0 device\n"); 104 return -ENODEV; 105 } 106 107 cpu_clk = clk_get(cpu_dev, NULL); 108 ret = PTR_ERR_OR_ZERO(cpu_clk); 109 if (ret) { 110 /* 111 * If cpu's clk node is present, but clock is not yet 112 * registered, we should try defering probe. 113 */ 114 if (ret == -EPROBE_DEFER) 115 dev_dbg(cpu_dev, "clock not ready, retry\n"); 116 else 117 dev_err(cpu_dev, "failed to get clock: %d\n", ret); 118 119 return ret; 120 } 121 122 clk_put(cpu_clk); 123 124 ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL); 125 if (ret) 126 return ret; 127 128 name = find_supply_name(cpu_dev); 129 /* Platform doesn't require regulator */ 130 if (!name) 131 return 0; 132 133 cpu_reg = regulator_get_optional(cpu_dev, name); 134 ret = PTR_ERR_OR_ZERO(cpu_reg); 135 if (ret) { 136 /* 137 * If cpu's regulator supply node is present, but regulator is 138 * not yet registered, we should try defering probe. 139 */ 140 if (ret == -EPROBE_DEFER) 141 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); 142 else 143 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret); 144 145 return ret; 146 } 147 148 regulator_put(cpu_reg); 149 return 0; 150 } 151 152 static int cpufreq_init(struct cpufreq_policy *policy) 153 { 154 struct cpufreq_frequency_table *freq_table; 155 struct opp_table *opp_table = NULL; 156 struct private_data *priv; 157 struct device *cpu_dev; 158 struct clk *cpu_clk; 159 unsigned int transition_latency; 160 bool fallback = false; 161 const char *name; 162 int ret; 163 164 cpu_dev = get_cpu_device(policy->cpu); 165 if (!cpu_dev) { 166 pr_err("failed to get cpu%d device\n", policy->cpu); 167 return -ENODEV; 168 } 169 170 cpu_clk = clk_get(cpu_dev, NULL); 171 if (IS_ERR(cpu_clk)) { 172 ret = PTR_ERR(cpu_clk); 173 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); 174 return ret; 175 } 176 177 /* Get OPP-sharing information from "operating-points-v2" bindings */ 178 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus); 179 if (ret) { 180 if (ret != -ENOENT) 181 goto out_put_clk; 182 183 /* 184 * operating-points-v2 not supported, fallback to old method of 185 * finding shared-OPPs for backward compatibility if the 186 * platform hasn't set sharing CPUs. 187 */ 188 if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus)) 189 fallback = true; 190 } 191 192 /* 193 * OPP layer will be taking care of regulators now, but it needs to know 194 * the name of the regulator first. 195 */ 196 name = find_supply_name(cpu_dev); 197 if (name) { 198 opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1); 199 if (IS_ERR(opp_table)) { 200 ret = PTR_ERR(opp_table); 201 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", 202 policy->cpu, ret); 203 goto out_put_clk; 204 } 205 } 206 207 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 208 if (!priv) { 209 ret = -ENOMEM; 210 goto out_put_regulator; 211 } 212 213 priv->reg_name = name; 214 priv->opp_table = opp_table; 215 216 /* 217 * Initialize OPP tables for all policy->cpus. They will be shared by 218 * all CPUs which have marked their CPUs shared with OPP bindings. 219 * 220 * For platforms not using operating-points-v2 bindings, we do this 221 * before updating policy->cpus. Otherwise, we will end up creating 222 * duplicate OPPs for policy->cpus. 223 * 224 * OPPs might be populated at runtime, don't check for error here 225 */ 226 if (!dev_pm_opp_of_cpumask_add_table(policy->cpus)) 227 priv->have_static_opps = true; 228 229 /* 230 * But we need OPP table to function so if it is not there let's 231 * give platform code chance to provide it for us. 232 */ 233 ret = dev_pm_opp_get_opp_count(cpu_dev); 234 if (ret <= 0) { 235 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); 236 ret = -EPROBE_DEFER; 237 goto out_free_opp; 238 } 239 240 if (fallback) { 241 cpumask_setall(policy->cpus); 242 243 /* 244 * OPP tables are initialized only for policy->cpu, do it for 245 * others as well. 246 */ 247 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); 248 if (ret) 249 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 250 __func__, ret); 251 } 252 253 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); 254 if (ret) { 255 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); 256 goto out_free_opp; 257 } 258 259 priv->cpu_dev = cpu_dev; 260 policy->driver_data = priv; 261 policy->clk = cpu_clk; 262 policy->freq_table = freq_table; 263 264 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; 265 266 /* Support turbo/boost mode */ 267 if (policy_has_boost_freq(policy)) { 268 /* This gets disabled by core on driver unregister */ 269 ret = cpufreq_enable_boost_support(); 270 if (ret) 271 goto out_free_cpufreq_table; 272 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 273 } 274 275 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 276 if (!transition_latency) 277 transition_latency = CPUFREQ_ETERNAL; 278 279 policy->cpuinfo.transition_latency = transition_latency; 280 policy->dvfs_possible_from_any_cpu = true; 281 282 dev_pm_opp_of_register_em(policy->cpus); 283 284 return 0; 285 286 out_free_cpufreq_table: 287 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); 288 out_free_opp: 289 if (priv->have_static_opps) 290 dev_pm_opp_of_cpumask_remove_table(policy->cpus); 291 kfree(priv); 292 out_put_regulator: 293 if (name) 294 dev_pm_opp_put_regulators(opp_table); 295 out_put_clk: 296 clk_put(cpu_clk); 297 298 return ret; 299 } 300 301 static int cpufreq_online(struct cpufreq_policy *policy) 302 { 303 /* We did light-weight tear down earlier, nothing to do here */ 304 return 0; 305 } 306 307 static int cpufreq_offline(struct cpufreq_policy *policy) 308 { 309 /* 310 * Preserve policy->driver_data and don't free resources on light-weight 311 * tear down. 312 */ 313 return 0; 314 } 315 316 static int cpufreq_exit(struct cpufreq_policy *policy) 317 { 318 struct private_data *priv = policy->driver_data; 319 320 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); 321 if (priv->have_static_opps) 322 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); 323 if (priv->reg_name) 324 dev_pm_opp_put_regulators(priv->opp_table); 325 326 clk_put(policy->clk); 327 kfree(priv); 328 329 return 0; 330 } 331 332 static struct cpufreq_driver dt_cpufreq_driver = { 333 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK | 334 CPUFREQ_IS_COOLING_DEV, 335 .verify = cpufreq_generic_frequency_table_verify, 336 .target_index = set_target, 337 .get = cpufreq_generic_get, 338 .init = cpufreq_init, 339 .exit = cpufreq_exit, 340 .online = cpufreq_online, 341 .offline = cpufreq_offline, 342 .name = "cpufreq-dt", 343 .attr = cpufreq_dt_attr, 344 .suspend = cpufreq_generic_suspend, 345 }; 346 347 static int dt_cpufreq_probe(struct platform_device *pdev) 348 { 349 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); 350 int ret; 351 352 /* 353 * All per-cluster (CPUs sharing clock/voltages) initialization is done 354 * from ->init(). In probe(), we just need to make sure that clk and 355 * regulators are available. Else defer probe and retry. 356 * 357 * FIXME: Is checking this only for CPU0 sufficient ? 358 */ 359 ret = resources_available(); 360 if (ret) 361 return ret; 362 363 if (data) { 364 if (data->have_governor_per_policy) 365 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; 366 367 dt_cpufreq_driver.resume = data->resume; 368 if (data->suspend) 369 dt_cpufreq_driver.suspend = data->suspend; 370 if (data->get_intermediate) { 371 dt_cpufreq_driver.target_intermediate = data->target_intermediate; 372 dt_cpufreq_driver.get_intermediate = data->get_intermediate; 373 } 374 } 375 376 ret = cpufreq_register_driver(&dt_cpufreq_driver); 377 if (ret) 378 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 379 380 return ret; 381 } 382 383 static int dt_cpufreq_remove(struct platform_device *pdev) 384 { 385 cpufreq_unregister_driver(&dt_cpufreq_driver); 386 return 0; 387 } 388 389 static struct platform_driver dt_cpufreq_platdrv = { 390 .driver = { 391 .name = "cpufreq-dt", 392 }, 393 .probe = dt_cpufreq_probe, 394 .remove = dt_cpufreq_remove, 395 }; 396 module_platform_driver(dt_cpufreq_platdrv); 397 398 MODULE_ALIAS("platform:cpufreq-dt"); 399 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 400 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 401 MODULE_DESCRIPTION("Generic cpufreq driver"); 402 MODULE_LICENSE("GPL"); 403