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 policy->freq_table = freq_table; 262 263 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; 264 265 /* Support turbo/boost mode */ 266 if (policy_has_boost_freq(policy)) { 267 /* This gets disabled by core on driver unregister */ 268 ret = cpufreq_enable_boost_support(); 269 if (ret) 270 goto out_free_cpufreq_table; 271 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 272 } 273 274 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 275 if (!transition_latency) 276 transition_latency = CPUFREQ_ETERNAL; 277 278 policy->cpuinfo.transition_latency = transition_latency; 279 policy->dvfs_possible_from_any_cpu = true; 280 281 return 0; 282 283 out_free_cpufreq_table: 284 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); 285 out_free_priv: 286 kfree(priv); 287 out_free_opp: 288 dev_pm_opp_of_cpumask_remove_table(policy->cpus); 289 if (name) 290 dev_pm_opp_put_regulators(opp_table); 291 out_put_clk: 292 clk_put(cpu_clk); 293 294 return ret; 295 } 296 297 static int cpufreq_exit(struct cpufreq_policy *policy) 298 { 299 struct private_data *priv = policy->driver_data; 300 301 cpufreq_cooling_unregister(priv->cdev); 302 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); 303 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); 304 if (priv->reg_name) 305 dev_pm_opp_put_regulators(priv->opp_table); 306 307 clk_put(policy->clk); 308 kfree(priv); 309 310 return 0; 311 } 312 313 static void cpufreq_ready(struct cpufreq_policy *policy) 314 { 315 struct private_data *priv = policy->driver_data; 316 317 priv->cdev = of_cpufreq_cooling_register(policy); 318 } 319 320 static struct cpufreq_driver dt_cpufreq_driver = { 321 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, 322 .verify = cpufreq_generic_frequency_table_verify, 323 .target_index = set_target, 324 .get = cpufreq_generic_get, 325 .init = cpufreq_init, 326 .exit = cpufreq_exit, 327 .ready = cpufreq_ready, 328 .name = "cpufreq-dt", 329 .attr = cpufreq_dt_attr, 330 .suspend = cpufreq_generic_suspend, 331 }; 332 333 static int dt_cpufreq_probe(struct platform_device *pdev) 334 { 335 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); 336 int ret; 337 338 /* 339 * All per-cluster (CPUs sharing clock/voltages) initialization is done 340 * from ->init(). In probe(), we just need to make sure that clk and 341 * regulators are available. Else defer probe and retry. 342 * 343 * FIXME: Is checking this only for CPU0 sufficient ? 344 */ 345 ret = resources_available(); 346 if (ret) 347 return ret; 348 349 if (data) { 350 if (data->have_governor_per_policy) 351 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; 352 353 dt_cpufreq_driver.resume = data->resume; 354 if (data->suspend) 355 dt_cpufreq_driver.suspend = data->suspend; 356 } 357 358 ret = cpufreq_register_driver(&dt_cpufreq_driver); 359 if (ret) 360 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 361 362 return ret; 363 } 364 365 static int dt_cpufreq_remove(struct platform_device *pdev) 366 { 367 cpufreq_unregister_driver(&dt_cpufreq_driver); 368 return 0; 369 } 370 371 static struct platform_driver dt_cpufreq_platdrv = { 372 .driver = { 373 .name = "cpufreq-dt", 374 }, 375 .probe = dt_cpufreq_probe, 376 .remove = dt_cpufreq_remove, 377 }; 378 module_platform_driver(dt_cpufreq_platdrv); 379 380 MODULE_ALIAS("platform:cpufreq-dt"); 381 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 382 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 383 MODULE_DESCRIPTION("Generic cpufreq driver"); 384 MODULE_LICENSE("GPL"); 385