1 /* 2 * Copyright (C) 2012 Freescale Semiconductor, Inc. 3 * 4 * Copyright (C) 2014 Linaro. 5 * Viresh Kumar <viresh.kumar@linaro.org> 6 * 7 * The OPP code in function set_target() is reused from 8 * drivers/cpufreq/omap-cpufreq.c 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 16 17 #include <linux/clk.h> 18 #include <linux/cpu.h> 19 #include <linux/cpu_cooling.h> 20 #include <linux/cpufreq.h> 21 #include <linux/cpufreq-dt.h> 22 #include <linux/cpumask.h> 23 #include <linux/err.h> 24 #include <linux/module.h> 25 #include <linux/of.h> 26 #include <linux/pm_opp.h> 27 #include <linux/platform_device.h> 28 #include <linux/regulator/consumer.h> 29 #include <linux/slab.h> 30 #include <linux/thermal.h> 31 32 struct private_data { 33 struct device *cpu_dev; 34 struct thermal_cooling_device *cdev; 35 const char *reg_name; 36 }; 37 38 static struct freq_attr *cpufreq_dt_attr[] = { 39 &cpufreq_freq_attr_scaling_available_freqs, 40 NULL, /* Extra space for boost-attr if required */ 41 NULL, 42 }; 43 44 static int set_target(struct cpufreq_policy *policy, unsigned int index) 45 { 46 struct private_data *priv = policy->driver_data; 47 48 return dev_pm_opp_set_rate(priv->cpu_dev, 49 policy->freq_table[index].frequency * 1000); 50 } 51 52 /* 53 * An earlier version of opp-v1 bindings used to name the regulator 54 * "cpu0-supply", we still need to handle that for backwards compatibility. 55 */ 56 static const char *find_supply_name(struct device *dev) 57 { 58 struct device_node *np; 59 struct property *pp; 60 int cpu = dev->id; 61 const char *name = NULL; 62 63 np = of_node_get(dev->of_node); 64 65 /* This must be valid for sure */ 66 if (WARN_ON(!np)) 67 return NULL; 68 69 /* Try "cpu0" for older DTs */ 70 if (!cpu) { 71 pp = of_find_property(np, "cpu0-supply", NULL); 72 if (pp) { 73 name = "cpu0"; 74 goto node_put; 75 } 76 } 77 78 pp = of_find_property(np, "cpu-supply", NULL); 79 if (pp) { 80 name = "cpu"; 81 goto node_put; 82 } 83 84 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 85 node_put: 86 of_node_put(np); 87 return name; 88 } 89 90 static int resources_available(void) 91 { 92 struct device *cpu_dev; 93 struct regulator *cpu_reg; 94 struct clk *cpu_clk; 95 int ret = 0; 96 const char *name; 97 98 cpu_dev = get_cpu_device(0); 99 if (!cpu_dev) { 100 pr_err("failed to get cpu0 device\n"); 101 return -ENODEV; 102 } 103 104 cpu_clk = clk_get(cpu_dev, NULL); 105 ret = PTR_ERR_OR_ZERO(cpu_clk); 106 if (ret) { 107 /* 108 * If cpu's clk node is present, but clock is not yet 109 * registered, we should try defering probe. 110 */ 111 if (ret == -EPROBE_DEFER) 112 dev_dbg(cpu_dev, "clock not ready, retry\n"); 113 else 114 dev_err(cpu_dev, "failed to get clock: %d\n", ret); 115 116 return ret; 117 } 118 119 clk_put(cpu_clk); 120 121 name = find_supply_name(cpu_dev); 122 /* Platform doesn't require regulator */ 123 if (!name) 124 return 0; 125 126 cpu_reg = regulator_get_optional(cpu_dev, name); 127 ret = PTR_ERR_OR_ZERO(cpu_reg); 128 if (ret) { 129 /* 130 * If cpu's regulator supply node is present, but regulator is 131 * not yet registered, we should try defering probe. 132 */ 133 if (ret == -EPROBE_DEFER) 134 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); 135 else 136 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret); 137 138 return ret; 139 } 140 141 regulator_put(cpu_reg); 142 return 0; 143 } 144 145 static int cpufreq_init(struct cpufreq_policy *policy) 146 { 147 struct cpufreq_frequency_table *freq_table; 148 struct private_data *priv; 149 struct device *cpu_dev; 150 struct clk *cpu_clk; 151 struct dev_pm_opp *suspend_opp; 152 unsigned int transition_latency; 153 bool opp_v1 = false; 154 const char *name; 155 int ret; 156 157 cpu_dev = get_cpu_device(policy->cpu); 158 if (!cpu_dev) { 159 pr_err("failed to get cpu%d device\n", policy->cpu); 160 return -ENODEV; 161 } 162 163 cpu_clk = clk_get(cpu_dev, NULL); 164 if (IS_ERR(cpu_clk)) { 165 ret = PTR_ERR(cpu_clk); 166 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); 167 return ret; 168 } 169 170 /* Get OPP-sharing information from "operating-points-v2" bindings */ 171 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus); 172 if (ret) { 173 /* 174 * operating-points-v2 not supported, fallback to old method of 175 * finding shared-OPPs for backward compatibility. 176 */ 177 if (ret == -ENOENT) 178 opp_v1 = true; 179 else 180 goto out_put_clk; 181 } 182 183 /* 184 * OPP layer will be taking care of regulators now, but it needs to know 185 * the name of the regulator first. 186 */ 187 name = find_supply_name(cpu_dev); 188 if (name) { 189 ret = dev_pm_opp_set_regulator(cpu_dev, name); 190 if (ret) { 191 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", 192 policy->cpu, ret); 193 goto out_put_clk; 194 } 195 } 196 197 /* 198 * Initialize OPP tables for all policy->cpus. They will be shared by 199 * all CPUs which have marked their CPUs shared with OPP bindings. 200 * 201 * For platforms not using operating-points-v2 bindings, we do this 202 * before updating policy->cpus. Otherwise, we will end up creating 203 * duplicate OPPs for policy->cpus. 204 * 205 * OPPs might be populated at runtime, don't check for error here 206 */ 207 dev_pm_opp_of_cpumask_add_table(policy->cpus); 208 209 /* 210 * But we need OPP table to function so if it is not there let's 211 * give platform code chance to provide it for us. 212 */ 213 ret = dev_pm_opp_get_opp_count(cpu_dev); 214 if (ret <= 0) { 215 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); 216 ret = -EPROBE_DEFER; 217 goto out_free_opp; 218 } 219 220 if (opp_v1) { 221 struct cpufreq_dt_platform_data *pd = cpufreq_get_driver_data(); 222 223 if (!pd || !pd->independent_clocks) 224 cpumask_setall(policy->cpus); 225 226 /* 227 * OPP tables are initialized only for policy->cpu, do it for 228 * others as well. 229 */ 230 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); 231 if (ret) 232 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 233 __func__, ret); 234 } 235 236 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 237 if (!priv) { 238 ret = -ENOMEM; 239 goto out_free_opp; 240 } 241 242 priv->reg_name = name; 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 rcu_read_lock(); 255 suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev); 256 if (suspend_opp) 257 policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000; 258 rcu_read_unlock(); 259 260 ret = cpufreq_table_validate_and_show(policy, freq_table); 261 if (ret) { 262 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, 263 ret); 264 goto out_free_cpufreq_table; 265 } 266 267 /* Support turbo/boost mode */ 268 if (policy_has_boost_freq(policy)) { 269 /* This gets disabled by core on driver unregister */ 270 ret = cpufreq_enable_boost_support(); 271 if (ret) 272 goto out_free_cpufreq_table; 273 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 274 } 275 276 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 277 if (!transition_latency) 278 transition_latency = CPUFREQ_ETERNAL; 279 280 policy->cpuinfo.transition_latency = transition_latency; 281 282 return 0; 283 284 out_free_cpufreq_table: 285 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); 286 out_free_priv: 287 kfree(priv); 288 out_free_opp: 289 dev_pm_opp_of_cpumask_remove_table(policy->cpus); 290 if (name) 291 dev_pm_opp_put_regulator(cpu_dev); 292 out_put_clk: 293 clk_put(cpu_clk); 294 295 return ret; 296 } 297 298 static int cpufreq_exit(struct cpufreq_policy *policy) 299 { 300 struct private_data *priv = policy->driver_data; 301 302 cpufreq_cooling_unregister(priv->cdev); 303 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); 304 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); 305 if (priv->reg_name) 306 dev_pm_opp_put_regulator(priv->cpu_dev); 307 308 clk_put(policy->clk); 309 kfree(priv); 310 311 return 0; 312 } 313 314 static void cpufreq_ready(struct cpufreq_policy *policy) 315 { 316 struct private_data *priv = policy->driver_data; 317 struct device_node *np = of_node_get(priv->cpu_dev->of_node); 318 319 if (WARN_ON(!np)) 320 return; 321 322 /* 323 * For now, just loading the cooling device; 324 * thermal DT code takes care of matching them. 325 */ 326 if (of_find_property(np, "#cooling-cells", NULL)) { 327 u32 power_coefficient = 0; 328 329 of_property_read_u32(np, "dynamic-power-coefficient", 330 &power_coefficient); 331 332 priv->cdev = of_cpufreq_power_cooling_register(np, 333 policy->related_cpus, power_coefficient, NULL); 334 if (IS_ERR(priv->cdev)) { 335 dev_err(priv->cpu_dev, 336 "running cpufreq without cooling device: %ld\n", 337 PTR_ERR(priv->cdev)); 338 339 priv->cdev = NULL; 340 } 341 } 342 343 of_node_put(np); 344 } 345 346 static struct cpufreq_driver dt_cpufreq_driver = { 347 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, 348 .verify = cpufreq_generic_frequency_table_verify, 349 .target_index = set_target, 350 .get = cpufreq_generic_get, 351 .init = cpufreq_init, 352 .exit = cpufreq_exit, 353 .ready = cpufreq_ready, 354 .name = "cpufreq-dt", 355 .attr = cpufreq_dt_attr, 356 .suspend = cpufreq_generic_suspend, 357 }; 358 359 static int dt_cpufreq_probe(struct platform_device *pdev) 360 { 361 int ret; 362 363 /* 364 * All per-cluster (CPUs sharing clock/voltages) initialization is done 365 * from ->init(). In probe(), we just need to make sure that clk and 366 * regulators are available. Else defer probe and retry. 367 * 368 * FIXME: Is checking this only for CPU0 sufficient ? 369 */ 370 ret = resources_available(); 371 if (ret) 372 return ret; 373 374 dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev); 375 376 ret = cpufreq_register_driver(&dt_cpufreq_driver); 377 if (ret) 378 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 379 380 return ret; 381 } 382 383 static int dt_cpufreq_remove(struct platform_device *pdev) 384 { 385 cpufreq_unregister_driver(&dt_cpufreq_driver); 386 return 0; 387 } 388 389 static struct platform_driver dt_cpufreq_platdrv = { 390 .driver = { 391 .name = "cpufreq-dt", 392 }, 393 .probe = dt_cpufreq_probe, 394 .remove = dt_cpufreq_remove, 395 }; 396 module_platform_driver(dt_cpufreq_platdrv); 397 398 MODULE_ALIAS("platform:cpufreq-dt"); 399 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 400 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 401 MODULE_DESCRIPTION("Generic cpufreq driver"); 402 MODULE_LICENSE("GPL"); 403