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