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 47 return dev_pm_opp_set_rate(priv->cpu_dev, 48 policy->freq_table[index].frequency * 1000); 49 } 50 51 /* 52 * An earlier version of opp-v1 bindings used to name the regulator 53 * "cpu0-supply", we still need to handle that for backwards compatibility. 54 */ 55 static const char *find_supply_name(struct device *dev) 56 { 57 struct device_node *np; 58 struct property *pp; 59 int cpu = dev->id; 60 const char *name = NULL; 61 62 np = of_node_get(dev->of_node); 63 64 /* This must be valid for sure */ 65 if (WARN_ON(!np)) 66 return NULL; 67 68 /* Try "cpu0" for older DTs */ 69 if (!cpu) { 70 pp = of_find_property(np, "cpu0-supply", NULL); 71 if (pp) { 72 name = "cpu0"; 73 goto node_put; 74 } 75 } 76 77 pp = of_find_property(np, "cpu-supply", NULL); 78 if (pp) { 79 name = "cpu"; 80 goto node_put; 81 } 82 83 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 84 node_put: 85 of_node_put(np); 86 return name; 87 } 88 89 static int resources_available(void) 90 { 91 struct device *cpu_dev; 92 struct regulator *cpu_reg; 93 struct clk *cpu_clk; 94 int ret = 0; 95 const char *name; 96 97 cpu_dev = get_cpu_device(0); 98 if (!cpu_dev) { 99 pr_err("failed to get cpu0 device\n"); 100 return -ENODEV; 101 } 102 103 cpu_clk = clk_get(cpu_dev, NULL); 104 ret = PTR_ERR_OR_ZERO(cpu_clk); 105 if (ret) { 106 /* 107 * If cpu's clk node is present, but clock is not yet 108 * registered, we should try defering probe. 109 */ 110 if (ret == -EPROBE_DEFER) 111 dev_dbg(cpu_dev, "clock not ready, retry\n"); 112 else 113 dev_err(cpu_dev, "failed to get clock: %d\n", ret); 114 115 return ret; 116 } 117 118 clk_put(cpu_clk); 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 /* 200 * Initialize OPP tables for all policy->cpus. They will be shared by 201 * all CPUs which have marked their CPUs shared with OPP bindings. 202 * 203 * For platforms not using operating-points-v2 bindings, we do this 204 * before updating policy->cpus. Otherwise, we will end up creating 205 * duplicate OPPs for policy->cpus. 206 * 207 * OPPs might be populated at runtime, don't check for error here 208 */ 209 dev_pm_opp_of_cpumask_add_table(policy->cpus); 210 211 /* 212 * But we need OPP table to function so if it is not there let's 213 * give platform code chance to provide it for us. 214 */ 215 ret = dev_pm_opp_get_opp_count(cpu_dev); 216 if (ret <= 0) { 217 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); 218 ret = -EPROBE_DEFER; 219 goto out_free_opp; 220 } 221 222 if (fallback) { 223 cpumask_setall(policy->cpus); 224 225 /* 226 * OPP tables are initialized only for policy->cpu, do it for 227 * others as well. 228 */ 229 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); 230 if (ret) 231 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 232 __func__, ret); 233 } 234 235 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 236 if (!priv) { 237 ret = -ENOMEM; 238 goto out_free_opp; 239 } 240 241 priv->reg_name = name; 242 priv->opp_table = opp_table; 243 244 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); 245 if (ret) { 246 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); 247 goto out_free_priv; 248 } 249 250 priv->cpu_dev = cpu_dev; 251 policy->driver_data = priv; 252 policy->clk = cpu_clk; 253 254 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; 255 256 ret = cpufreq_table_validate_and_show(policy, freq_table); 257 if (ret) { 258 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, 259 ret); 260 goto out_free_cpufreq_table; 261 } 262 263 /* Support turbo/boost mode */ 264 if (policy_has_boost_freq(policy)) { 265 /* This gets disabled by core on driver unregister */ 266 ret = cpufreq_enable_boost_support(); 267 if (ret) 268 goto out_free_cpufreq_table; 269 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 270 } 271 272 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 273 if (!transition_latency) 274 transition_latency = CPUFREQ_ETERNAL; 275 276 policy->cpuinfo.transition_latency = transition_latency; 277 policy->dvfs_possible_from_any_cpu = true; 278 279 return 0; 280 281 out_free_cpufreq_table: 282 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); 283 out_free_priv: 284 kfree(priv); 285 out_free_opp: 286 dev_pm_opp_of_cpumask_remove_table(policy->cpus); 287 if (name) 288 dev_pm_opp_put_regulators(opp_table); 289 out_put_clk: 290 clk_put(cpu_clk); 291 292 return ret; 293 } 294 295 static int cpufreq_exit(struct cpufreq_policy *policy) 296 { 297 struct private_data *priv = policy->driver_data; 298 299 cpufreq_cooling_unregister(priv->cdev); 300 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); 301 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); 302 if (priv->reg_name) 303 dev_pm_opp_put_regulators(priv->opp_table); 304 305 clk_put(policy->clk); 306 kfree(priv); 307 308 return 0; 309 } 310 311 static void cpufreq_ready(struct cpufreq_policy *policy) 312 { 313 struct private_data *priv = policy->driver_data; 314 struct device_node *np = of_node_get(priv->cpu_dev->of_node); 315 316 if (WARN_ON(!np)) 317 return; 318 319 /* 320 * For now, just loading the cooling device; 321 * thermal DT code takes care of matching them. 322 */ 323 if (of_find_property(np, "#cooling-cells", NULL)) { 324 u32 power_coefficient = 0; 325 326 of_property_read_u32(np, "dynamic-power-coefficient", 327 &power_coefficient); 328 329 priv->cdev = of_cpufreq_power_cooling_register(np, 330 policy, power_coefficient, NULL); 331 if (IS_ERR(priv->cdev)) { 332 dev_err(priv->cpu_dev, 333 "running cpufreq without cooling device: %ld\n", 334 PTR_ERR(priv->cdev)); 335 336 priv->cdev = NULL; 337 } 338 } 339 340 of_node_put(np); 341 } 342 343 static struct cpufreq_driver dt_cpufreq_driver = { 344 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, 345 .verify = cpufreq_generic_frequency_table_verify, 346 .target_index = set_target, 347 .get = cpufreq_generic_get, 348 .init = cpufreq_init, 349 .exit = cpufreq_exit, 350 .ready = cpufreq_ready, 351 .name = "cpufreq-dt", 352 .attr = cpufreq_dt_attr, 353 .suspend = cpufreq_generic_suspend, 354 }; 355 356 static int dt_cpufreq_probe(struct platform_device *pdev) 357 { 358 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); 359 int ret; 360 361 /* 362 * All per-cluster (CPUs sharing clock/voltages) initialization is done 363 * from ->init(). In probe(), we just need to make sure that clk and 364 * regulators are available. Else defer probe and retry. 365 * 366 * FIXME: Is checking this only for CPU0 sufficient ? 367 */ 368 ret = resources_available(); 369 if (ret) 370 return ret; 371 372 if (data && data->have_governor_per_policy) 373 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; 374 375 ret = cpufreq_register_driver(&dt_cpufreq_driver); 376 if (ret) 377 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 378 379 return ret; 380 } 381 382 static int dt_cpufreq_remove(struct platform_device *pdev) 383 { 384 cpufreq_unregister_driver(&dt_cpufreq_driver); 385 return 0; 386 } 387 388 static struct platform_driver dt_cpufreq_platdrv = { 389 .driver = { 390 .name = "cpufreq-dt", 391 }, 392 .probe = dt_cpufreq_probe, 393 .remove = dt_cpufreq_remove, 394 }; 395 module_platform_driver(dt_cpufreq_platdrv); 396 397 MODULE_ALIAS("platform:cpufreq-dt"); 398 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 399 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 400 MODULE_DESCRIPTION("Generic cpufreq driver"); 401 MODULE_LICENSE("GPL"); 402