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/cpufreq-dt.h> 19 #include <linux/cpumask.h> 20 #include <linux/err.h> 21 #include <linux/module.h> 22 #include <linux/of.h> 23 #include <linux/pm_opp.h> 24 #include <linux/platform_device.h> 25 #include <linux/regulator/consumer.h> 26 #include <linux/slab.h> 27 #include <linux/thermal.h> 28 29 struct private_data { 30 struct device *cpu_dev; 31 struct thermal_cooling_device *cdev; 32 const char *reg_name; 33 }; 34 35 static struct freq_attr *cpufreq_dt_attr[] = { 36 &cpufreq_freq_attr_scaling_available_freqs, 37 NULL, /* Extra space for boost-attr if required */ 38 NULL, 39 }; 40 41 static int set_target(struct cpufreq_policy *policy, unsigned int index) 42 { 43 struct private_data *priv = policy->driver_data; 44 45 return dev_pm_opp_set_rate(priv->cpu_dev, 46 policy->freq_table[index].frequency * 1000); 47 } 48 49 /* 50 * An earlier version of opp-v1 bindings used to name the regulator 51 * "cpu0-supply", we still need to handle that for backwards compatibility. 52 */ 53 static const char *find_supply_name(struct device *dev) 54 { 55 struct device_node *np; 56 struct property *pp; 57 int cpu = dev->id; 58 const char *name = NULL; 59 60 np = of_node_get(dev->of_node); 61 62 /* This must be valid for sure */ 63 if (WARN_ON(!np)) 64 return NULL; 65 66 /* Try "cpu0" for older DTs */ 67 if (!cpu) { 68 pp = of_find_property(np, "cpu0-supply", NULL); 69 if (pp) { 70 name = "cpu0"; 71 goto node_put; 72 } 73 } 74 75 pp = of_find_property(np, "cpu-supply", NULL); 76 if (pp) { 77 name = "cpu"; 78 goto node_put; 79 } 80 81 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 82 node_put: 83 of_node_put(np); 84 return name; 85 } 86 87 static int resources_available(void) 88 { 89 struct device *cpu_dev; 90 struct regulator *cpu_reg; 91 struct clk *cpu_clk; 92 int ret = 0; 93 const char *name; 94 95 cpu_dev = get_cpu_device(0); 96 if (!cpu_dev) { 97 pr_err("failed to get cpu0 device\n"); 98 return -ENODEV; 99 } 100 101 cpu_clk = clk_get(cpu_dev, NULL); 102 ret = PTR_ERR_OR_ZERO(cpu_clk); 103 if (ret) { 104 /* 105 * If cpu's clk node is present, but clock is not yet 106 * registered, we should try defering probe. 107 */ 108 if (ret == -EPROBE_DEFER) 109 dev_dbg(cpu_dev, "clock not ready, retry\n"); 110 else 111 dev_err(cpu_dev, "failed to get clock: %d\n", ret); 112 113 return ret; 114 } 115 116 clk_put(cpu_clk); 117 118 name = find_supply_name(cpu_dev); 119 /* Platform doesn't require regulator */ 120 if (!name) 121 return 0; 122 123 cpu_reg = regulator_get_optional(cpu_dev, name); 124 ret = PTR_ERR_OR_ZERO(cpu_reg); 125 if (ret) { 126 /* 127 * If cpu's regulator supply node is present, but regulator is 128 * not yet registered, we should try defering probe. 129 */ 130 if (ret == -EPROBE_DEFER) 131 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); 132 else 133 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret); 134 135 return ret; 136 } 137 138 regulator_put(cpu_reg); 139 return 0; 140 } 141 142 static int cpufreq_init(struct cpufreq_policy *policy) 143 { 144 struct cpufreq_frequency_table *freq_table; 145 struct private_data *priv; 146 struct device *cpu_dev; 147 struct clk *cpu_clk; 148 struct dev_pm_opp *suspend_opp; 149 unsigned int transition_latency; 150 bool opp_v1 = false; 151 const char *name; 152 int ret; 153 154 cpu_dev = get_cpu_device(policy->cpu); 155 if (!cpu_dev) { 156 pr_err("failed to get cpu%d device\n", policy->cpu); 157 return -ENODEV; 158 } 159 160 cpu_clk = clk_get(cpu_dev, NULL); 161 if (IS_ERR(cpu_clk)) { 162 ret = PTR_ERR(cpu_clk); 163 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); 164 return ret; 165 } 166 167 /* Get OPP-sharing information from "operating-points-v2" bindings */ 168 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus); 169 if (ret) { 170 /* 171 * operating-points-v2 not supported, fallback to old method of 172 * finding shared-OPPs for backward compatibility. 173 */ 174 if (ret == -ENOENT) 175 opp_v1 = true; 176 else 177 goto out_put_clk; 178 } 179 180 /* 181 * OPP layer will be taking care of regulators now, but it needs to know 182 * the name of the regulator first. 183 */ 184 name = find_supply_name(cpu_dev); 185 if (name) { 186 ret = dev_pm_opp_set_regulator(cpu_dev, name); 187 if (ret) { 188 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", 189 policy->cpu, ret); 190 goto out_put_clk; 191 } 192 } 193 194 /* 195 * Initialize OPP tables for all policy->cpus. They will be shared by 196 * all CPUs which have marked their CPUs shared with OPP bindings. 197 * 198 * For platforms not using operating-points-v2 bindings, we do this 199 * before updating policy->cpus. Otherwise, we will end up creating 200 * duplicate OPPs for policy->cpus. 201 * 202 * OPPs might be populated at runtime, don't check for error here 203 */ 204 dev_pm_opp_of_cpumask_add_table(policy->cpus); 205 206 /* 207 * But we need OPP table to function so if it is not there let's 208 * give platform code chance to provide it for us. 209 */ 210 ret = dev_pm_opp_get_opp_count(cpu_dev); 211 if (ret <= 0) { 212 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); 213 ret = -EPROBE_DEFER; 214 goto out_free_opp; 215 } 216 217 if (opp_v1) { 218 struct cpufreq_dt_platform_data *pd = cpufreq_get_driver_data(); 219 220 if (!pd || !pd->independent_clocks) 221 cpumask_setall(policy->cpus); 222 223 /* 224 * OPP tables are initialized only for policy->cpu, do it for 225 * others as well. 226 */ 227 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); 228 if (ret) 229 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 230 __func__, ret); 231 } 232 233 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 234 if (!priv) { 235 ret = -ENOMEM; 236 goto out_free_opp; 237 } 238 239 priv->reg_name = name; 240 241 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); 242 if (ret) { 243 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); 244 goto out_free_priv; 245 } 246 247 priv->cpu_dev = cpu_dev; 248 policy->driver_data = priv; 249 policy->clk = cpu_clk; 250 251 rcu_read_lock(); 252 suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev); 253 if (suspend_opp) 254 policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000; 255 rcu_read_unlock(); 256 257 ret = cpufreq_table_validate_and_show(policy, freq_table); 258 if (ret) { 259 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, 260 ret); 261 goto out_free_cpufreq_table; 262 } 263 264 /* Support turbo/boost mode */ 265 if (policy_has_boost_freq(policy)) { 266 /* This gets disabled by core on driver unregister */ 267 ret = cpufreq_enable_boost_support(); 268 if (ret) 269 goto out_free_cpufreq_table; 270 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 271 } 272 273 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 274 if (!transition_latency) 275 transition_latency = CPUFREQ_ETERNAL; 276 277 policy->cpuinfo.transition_latency = transition_latency; 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_regulator(cpu_dev); 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_regulator(priv->cpu_dev); 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->related_cpus, 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 int ret; 359 360 /* 361 * All per-cluster (CPUs sharing clock/voltages) initialization is done 362 * from ->init(). In probe(), we just need to make sure that clk and 363 * regulators are available. Else defer probe and retry. 364 * 365 * FIXME: Is checking this only for CPU0 sufficient ? 366 */ 367 ret = resources_available(); 368 if (ret) 369 return ret; 370 371 dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev); 372 373 ret = cpufreq_register_driver(&dt_cpufreq_driver); 374 if (ret) 375 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 376 377 return ret; 378 } 379 380 static int dt_cpufreq_remove(struct platform_device *pdev) 381 { 382 cpufreq_unregister_driver(&dt_cpufreq_driver); 383 return 0; 384 } 385 386 static struct platform_driver dt_cpufreq_platdrv = { 387 .driver = { 388 .name = "cpufreq-dt", 389 }, 390 .probe = dt_cpufreq_probe, 391 .remove = dt_cpufreq_remove, 392 }; 393 module_platform_driver(dt_cpufreq_platdrv); 394 395 MODULE_ALIAS("platform:cpufreq-dt"); 396 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 397 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 398 MODULE_DESCRIPTION("Generic cpufreq driver"); 399 MODULE_LICENSE("GPL"); 400