1 /* 2 * Copyright (C) 2012 Freescale Semiconductor, Inc. 3 * 4 * Copyright (C) 2014 Linaro. 5 * Viresh Kumar <viresh.kumar@linaro.org> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/clk.h> 15 #include <linux/cpu.h> 16 #include <linux/cpu_cooling.h> 17 #include <linux/cpufreq.h> 18 #include <linux/cpumask.h> 19 #include <linux/err.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/pm_opp.h> 23 #include <linux/platform_device.h> 24 #include <linux/regulator/consumer.h> 25 #include <linux/slab.h> 26 #include <linux/thermal.h> 27 28 #include "cpufreq-dt.h" 29 30 struct private_data { 31 struct opp_table *opp_table; 32 struct device *cpu_dev; 33 struct thermal_cooling_device *cdev; 34 const char *reg_name; 35 }; 36 37 static struct freq_attr *cpufreq_dt_attr[] = { 38 &cpufreq_freq_attr_scaling_available_freqs, 39 NULL, /* Extra space for boost-attr if required */ 40 NULL, 41 }; 42 43 static int set_target(struct cpufreq_policy *policy, unsigned int index) 44 { 45 struct private_data *priv = policy->driver_data; 46 unsigned long freq = policy->freq_table[index].frequency; 47 int ret; 48 49 ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000); 50 51 if (!ret) { 52 arch_set_freq_scale(policy->related_cpus, freq, 53 policy->cpuinfo.max_freq); 54 } 55 56 return ret; 57 } 58 59 /* 60 * An earlier version of opp-v1 bindings used to name the regulator 61 * "cpu0-supply", we still need to handle that for backwards compatibility. 62 */ 63 static const char *find_supply_name(struct device *dev) 64 { 65 struct device_node *np; 66 struct property *pp; 67 int cpu = dev->id; 68 const char *name = NULL; 69 70 np = of_node_get(dev->of_node); 71 72 /* This must be valid for sure */ 73 if (WARN_ON(!np)) 74 return NULL; 75 76 /* Try "cpu0" for older DTs */ 77 if (!cpu) { 78 pp = of_find_property(np, "cpu0-supply", NULL); 79 if (pp) { 80 name = "cpu0"; 81 goto node_put; 82 } 83 } 84 85 pp = of_find_property(np, "cpu-supply", NULL); 86 if (pp) { 87 name = "cpu"; 88 goto node_put; 89 } 90 91 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 92 node_put: 93 of_node_put(np); 94 return name; 95 } 96 97 static int resources_available(void) 98 { 99 struct device *cpu_dev; 100 struct regulator *cpu_reg; 101 struct clk *cpu_clk; 102 int ret = 0; 103 const char *name; 104 105 cpu_dev = get_cpu_device(0); 106 if (!cpu_dev) { 107 pr_err("failed to get cpu0 device\n"); 108 return -ENODEV; 109 } 110 111 cpu_clk = clk_get(cpu_dev, NULL); 112 ret = PTR_ERR_OR_ZERO(cpu_clk); 113 if (ret) { 114 /* 115 * If cpu's clk node is present, but clock is not yet 116 * registered, we should try defering probe. 117 */ 118 if (ret == -EPROBE_DEFER) 119 dev_dbg(cpu_dev, "clock not ready, retry\n"); 120 else 121 dev_err(cpu_dev, "failed to get clock: %d\n", ret); 122 123 return ret; 124 } 125 126 clk_put(cpu_clk); 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 /* 208 * Initialize OPP tables for all policy->cpus. They will be shared by 209 * all CPUs which have marked their CPUs shared with OPP bindings. 210 * 211 * For platforms not using operating-points-v2 bindings, we do this 212 * before updating policy->cpus. Otherwise, we will end up creating 213 * duplicate OPPs for policy->cpus. 214 * 215 * OPPs might be populated at runtime, don't check for error here 216 */ 217 dev_pm_opp_of_cpumask_add_table(policy->cpus); 218 219 /* 220 * But we need OPP table to function so if it is not there let's 221 * give platform code chance to provide it for us. 222 */ 223 ret = dev_pm_opp_get_opp_count(cpu_dev); 224 if (ret <= 0) { 225 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); 226 ret = -EPROBE_DEFER; 227 goto out_free_opp; 228 } 229 230 if (fallback) { 231 cpumask_setall(policy->cpus); 232 233 /* 234 * OPP tables are initialized only for policy->cpu, do it for 235 * others as well. 236 */ 237 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); 238 if (ret) 239 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 240 __func__, ret); 241 } 242 243 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 244 if (!priv) { 245 ret = -ENOMEM; 246 goto out_free_opp; 247 } 248 249 priv->reg_name = name; 250 priv->opp_table = opp_table; 251 252 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); 253 if (ret) { 254 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); 255 goto out_free_priv; 256 } 257 258 priv->cpu_dev = cpu_dev; 259 policy->driver_data = priv; 260 policy->clk = cpu_clk; 261 262 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; 263 264 ret = cpufreq_table_validate_and_show(policy, freq_table); 265 if (ret) { 266 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, 267 ret); 268 goto out_free_cpufreq_table; 269 } 270 271 /* Support turbo/boost mode */ 272 if (policy_has_boost_freq(policy)) { 273 /* This gets disabled by core on driver unregister */ 274 ret = cpufreq_enable_boost_support(); 275 if (ret) 276 goto out_free_cpufreq_table; 277 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 278 } 279 280 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 281 if (!transition_latency) 282 transition_latency = CPUFREQ_ETERNAL; 283 284 policy->cpuinfo.transition_latency = transition_latency; 285 policy->dvfs_possible_from_any_cpu = true; 286 287 return 0; 288 289 out_free_cpufreq_table: 290 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); 291 out_free_priv: 292 kfree(priv); 293 out_free_opp: 294 dev_pm_opp_of_cpumask_remove_table(policy->cpus); 295 if (name) 296 dev_pm_opp_put_regulators(opp_table); 297 out_put_clk: 298 clk_put(cpu_clk); 299 300 return ret; 301 } 302 303 static int cpufreq_exit(struct cpufreq_policy *policy) 304 { 305 struct private_data *priv = policy->driver_data; 306 307 cpufreq_cooling_unregister(priv->cdev); 308 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); 309 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); 310 if (priv->reg_name) 311 dev_pm_opp_put_regulators(priv->opp_table); 312 313 clk_put(policy->clk); 314 kfree(priv); 315 316 return 0; 317 } 318 319 static void cpufreq_ready(struct cpufreq_policy *policy) 320 { 321 struct private_data *priv = policy->driver_data; 322 struct device_node *np = of_node_get(priv->cpu_dev->of_node); 323 324 if (WARN_ON(!np)) 325 return; 326 327 /* 328 * For now, just loading the cooling device; 329 * thermal DT code takes care of matching them. 330 */ 331 if (of_find_property(np, "#cooling-cells", NULL)) { 332 u32 power_coefficient = 0; 333 334 of_property_read_u32(np, "dynamic-power-coefficient", 335 &power_coefficient); 336 337 priv->cdev = of_cpufreq_power_cooling_register(np, 338 policy, power_coefficient, NULL); 339 if (IS_ERR(priv->cdev)) { 340 dev_err(priv->cpu_dev, 341 "running cpufreq without cooling device: %ld\n", 342 PTR_ERR(priv->cdev)); 343 344 priv->cdev = NULL; 345 } 346 } 347 348 of_node_put(np); 349 } 350 351 static struct cpufreq_driver dt_cpufreq_driver = { 352 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, 353 .verify = cpufreq_generic_frequency_table_verify, 354 .target_index = set_target, 355 .get = cpufreq_generic_get, 356 .init = cpufreq_init, 357 .exit = cpufreq_exit, 358 .ready = cpufreq_ready, 359 .name = "cpufreq-dt", 360 .attr = cpufreq_dt_attr, 361 .suspend = cpufreq_generic_suspend, 362 }; 363 364 static int dt_cpufreq_probe(struct platform_device *pdev) 365 { 366 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); 367 int ret; 368 369 /* 370 * All per-cluster (CPUs sharing clock/voltages) initialization is done 371 * from ->init(). In probe(), we just need to make sure that clk and 372 * regulators are available. Else defer probe and retry. 373 * 374 * FIXME: Is checking this only for CPU0 sufficient ? 375 */ 376 ret = resources_available(); 377 if (ret) 378 return ret; 379 380 if (data && data->have_governor_per_policy) 381 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; 382 383 ret = cpufreq_register_driver(&dt_cpufreq_driver); 384 if (ret) 385 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 386 387 return ret; 388 } 389 390 static int dt_cpufreq_remove(struct platform_device *pdev) 391 { 392 cpufreq_unregister_driver(&dt_cpufreq_driver); 393 return 0; 394 } 395 396 static struct platform_driver dt_cpufreq_platdrv = { 397 .driver = { 398 .name = "cpufreq-dt", 399 }, 400 .probe = dt_cpufreq_probe, 401 .remove = dt_cpufreq_remove, 402 }; 403 module_platform_driver(dt_cpufreq_platdrv); 404 405 MODULE_ALIAS("platform:cpufreq-dt"); 406 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 407 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 408 MODULE_DESCRIPTION("Generic cpufreq driver"); 409 MODULE_LICENSE("GPL"); 410