1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Freescale Semiconductor, Inc. 4 * 5 * Copyright (C) 2014 Linaro. 6 * Viresh Kumar <viresh.kumar@linaro.org> 7 */ 8 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/clk.h> 12 #include <linux/cpu.h> 13 #include <linux/cpufreq.h> 14 #include <linux/cpumask.h> 15 #include <linux/err.h> 16 #include <linux/list.h> 17 #include <linux/module.h> 18 #include <linux/of.h> 19 #include <linux/pm_opp.h> 20 #include <linux/platform_device.h> 21 #include <linux/regulator/consumer.h> 22 #include <linux/slab.h> 23 #include <linux/thermal.h> 24 25 #include "cpufreq-dt.h" 26 27 struct private_data { 28 struct list_head node; 29 30 cpumask_var_t cpus; 31 struct device *cpu_dev; 32 struct cpufreq_frequency_table *freq_table; 33 bool have_static_opps; 34 int opp_token; 35 }; 36 37 static LIST_HEAD(priv_list); 38 39 static struct freq_attr *cpufreq_dt_attr[] = { 40 &cpufreq_freq_attr_scaling_available_freqs, 41 NULL, /* Extra space for boost-attr if required */ 42 NULL, 43 }; 44 45 static struct private_data *cpufreq_dt_find_data(int cpu) 46 { 47 struct private_data *priv; 48 49 list_for_each_entry(priv, &priv_list, node) { 50 if (cpumask_test_cpu(cpu, priv->cpus)) 51 return priv; 52 } 53 54 return NULL; 55 } 56 57 static int set_target(struct cpufreq_policy *policy, unsigned int index) 58 { 59 struct private_data *priv = policy->driver_data; 60 unsigned long freq = policy->freq_table[index].frequency; 61 62 return dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000); 63 } 64 65 /* 66 * An earlier version of opp-v1 bindings used to name the regulator 67 * "cpu0-supply", we still need to handle that for backwards compatibility. 68 */ 69 static const char *find_supply_name(struct device *dev) 70 { 71 struct device_node *np; 72 struct property *pp; 73 int cpu = dev->id; 74 const char *name = NULL; 75 76 np = of_node_get(dev->of_node); 77 78 /* This must be valid for sure */ 79 if (WARN_ON(!np)) 80 return NULL; 81 82 /* Try "cpu0" for older DTs */ 83 if (!cpu) { 84 pp = of_find_property(np, "cpu0-supply", NULL); 85 if (pp) { 86 name = "cpu0"; 87 goto node_put; 88 } 89 } 90 91 pp = of_find_property(np, "cpu-supply", NULL); 92 if (pp) { 93 name = "cpu"; 94 goto node_put; 95 } 96 97 dev_dbg(dev, "no regulator for cpu%d\n", cpu); 98 node_put: 99 of_node_put(np); 100 return name; 101 } 102 103 static int cpufreq_init(struct cpufreq_policy *policy) 104 { 105 struct private_data *priv; 106 struct device *cpu_dev; 107 struct clk *cpu_clk; 108 unsigned int transition_latency; 109 int ret; 110 111 priv = cpufreq_dt_find_data(policy->cpu); 112 if (!priv) { 113 pr_err("failed to find data for cpu%d\n", policy->cpu); 114 return -ENODEV; 115 } 116 cpu_dev = priv->cpu_dev; 117 118 cpu_clk = clk_get(cpu_dev, NULL); 119 if (IS_ERR(cpu_clk)) { 120 ret = PTR_ERR(cpu_clk); 121 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); 122 return ret; 123 } 124 125 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); 126 if (!transition_latency) 127 transition_latency = CPUFREQ_ETERNAL; 128 129 cpumask_copy(policy->cpus, priv->cpus); 130 policy->driver_data = priv; 131 policy->clk = cpu_clk; 132 policy->freq_table = priv->freq_table; 133 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; 134 policy->cpuinfo.transition_latency = transition_latency; 135 policy->dvfs_possible_from_any_cpu = true; 136 137 /* Support turbo/boost mode */ 138 if (policy_has_boost_freq(policy)) { 139 /* This gets disabled by core on driver unregister */ 140 ret = cpufreq_enable_boost_support(); 141 if (ret) 142 goto out_clk_put; 143 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; 144 } 145 146 return 0; 147 148 out_clk_put: 149 clk_put(cpu_clk); 150 151 return ret; 152 } 153 154 static int cpufreq_online(struct cpufreq_policy *policy) 155 { 156 /* We did light-weight tear down earlier, nothing to do here */ 157 return 0; 158 } 159 160 static int cpufreq_offline(struct cpufreq_policy *policy) 161 { 162 /* 163 * Preserve policy->driver_data and don't free resources on light-weight 164 * tear down. 165 */ 166 return 0; 167 } 168 169 static int cpufreq_exit(struct cpufreq_policy *policy) 170 { 171 clk_put(policy->clk); 172 return 0; 173 } 174 175 static struct cpufreq_driver dt_cpufreq_driver = { 176 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK | 177 CPUFREQ_IS_COOLING_DEV, 178 .verify = cpufreq_generic_frequency_table_verify, 179 .target_index = set_target, 180 .get = cpufreq_generic_get, 181 .init = cpufreq_init, 182 .exit = cpufreq_exit, 183 .online = cpufreq_online, 184 .offline = cpufreq_offline, 185 .register_em = cpufreq_register_em_with_opp, 186 .name = "cpufreq-dt", 187 .attr = cpufreq_dt_attr, 188 .suspend = cpufreq_generic_suspend, 189 }; 190 191 static int dt_cpufreq_early_init(struct device *dev, int cpu) 192 { 193 struct private_data *priv; 194 struct device *cpu_dev; 195 bool fallback = false; 196 const char *reg_name[] = { NULL, NULL }; 197 int ret; 198 199 /* Check if this CPU is already covered by some other policy */ 200 if (cpufreq_dt_find_data(cpu)) 201 return 0; 202 203 cpu_dev = get_cpu_device(cpu); 204 if (!cpu_dev) 205 return -EPROBE_DEFER; 206 207 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 208 if (!priv) 209 return -ENOMEM; 210 211 if (!alloc_cpumask_var(&priv->cpus, GFP_KERNEL)) 212 return -ENOMEM; 213 214 cpumask_set_cpu(cpu, priv->cpus); 215 priv->cpu_dev = cpu_dev; 216 217 /* 218 * OPP layer will be taking care of regulators now, but it needs to know 219 * the name of the regulator first. 220 */ 221 reg_name[0] = find_supply_name(cpu_dev); 222 if (reg_name[0]) { 223 priv->opp_token = dev_pm_opp_set_regulators(cpu_dev, reg_name); 224 if (priv->opp_token < 0) { 225 ret = priv->opp_token; 226 if (ret != -EPROBE_DEFER) 227 dev_err(cpu_dev, "failed to set regulators: %d\n", 228 ret); 229 goto free_cpumask; 230 } 231 } 232 233 /* Get OPP-sharing information from "operating-points-v2" bindings */ 234 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->cpus); 235 if (ret) { 236 if (ret != -ENOENT) 237 goto out; 238 239 /* 240 * operating-points-v2 not supported, fallback to all CPUs share 241 * OPP for backward compatibility if the platform hasn't set 242 * sharing CPUs. 243 */ 244 if (dev_pm_opp_get_sharing_cpus(cpu_dev, priv->cpus)) 245 fallback = true; 246 } 247 248 /* 249 * Initialize OPP tables for all priv->cpus. They will be shared by 250 * all CPUs which have marked their CPUs shared with OPP bindings. 251 * 252 * For platforms not using operating-points-v2 bindings, we do this 253 * before updating priv->cpus. Otherwise, we will end up creating 254 * duplicate OPPs for the CPUs. 255 * 256 * OPPs might be populated at runtime, don't fail for error here unless 257 * it is -EPROBE_DEFER. 258 */ 259 ret = dev_pm_opp_of_cpumask_add_table(priv->cpus); 260 if (!ret) { 261 priv->have_static_opps = true; 262 } else if (ret == -EPROBE_DEFER) { 263 goto out; 264 } 265 266 /* 267 * The OPP table must be initialized, statically or dynamically, by this 268 * point. 269 */ 270 ret = dev_pm_opp_get_opp_count(cpu_dev); 271 if (ret <= 0) { 272 dev_err(cpu_dev, "OPP table can't be empty\n"); 273 ret = -ENODEV; 274 goto out; 275 } 276 277 if (fallback) { 278 cpumask_setall(priv->cpus); 279 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->cpus); 280 if (ret) 281 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", 282 __func__, ret); 283 } 284 285 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &priv->freq_table); 286 if (ret) { 287 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); 288 goto out; 289 } 290 291 list_add(&priv->node, &priv_list); 292 return 0; 293 294 out: 295 if (priv->have_static_opps) 296 dev_pm_opp_of_cpumask_remove_table(priv->cpus); 297 dev_pm_opp_put_regulators(priv->opp_token); 298 free_cpumask: 299 free_cpumask_var(priv->cpus); 300 return ret; 301 } 302 303 static void dt_cpufreq_release(void) 304 { 305 struct private_data *priv, *tmp; 306 307 list_for_each_entry_safe(priv, tmp, &priv_list, node) { 308 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &priv->freq_table); 309 if (priv->have_static_opps) 310 dev_pm_opp_of_cpumask_remove_table(priv->cpus); 311 dev_pm_opp_put_regulators(priv->opp_token); 312 free_cpumask_var(priv->cpus); 313 list_del(&priv->node); 314 } 315 } 316 317 static int dt_cpufreq_probe(struct platform_device *pdev) 318 { 319 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); 320 int ret, cpu; 321 322 /* Request resources early so we can return in case of -EPROBE_DEFER */ 323 for_each_possible_cpu(cpu) { 324 ret = dt_cpufreq_early_init(&pdev->dev, cpu); 325 if (ret) 326 goto err; 327 } 328 329 if (data) { 330 if (data->have_governor_per_policy) 331 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; 332 333 dt_cpufreq_driver.resume = data->resume; 334 if (data->suspend) 335 dt_cpufreq_driver.suspend = data->suspend; 336 if (data->get_intermediate) { 337 dt_cpufreq_driver.target_intermediate = data->target_intermediate; 338 dt_cpufreq_driver.get_intermediate = data->get_intermediate; 339 } 340 } 341 342 ret = cpufreq_register_driver(&dt_cpufreq_driver); 343 if (ret) { 344 dev_err(&pdev->dev, "failed register driver: %d\n", ret); 345 goto err; 346 } 347 348 return 0; 349 err: 350 dt_cpufreq_release(); 351 return ret; 352 } 353 354 static int dt_cpufreq_remove(struct platform_device *pdev) 355 { 356 cpufreq_unregister_driver(&dt_cpufreq_driver); 357 dt_cpufreq_release(); 358 return 0; 359 } 360 361 static struct platform_driver dt_cpufreq_platdrv = { 362 .driver = { 363 .name = "cpufreq-dt", 364 }, 365 .probe = dt_cpufreq_probe, 366 .remove = dt_cpufreq_remove, 367 }; 368 module_platform_driver(dt_cpufreq_platdrv); 369 370 MODULE_ALIAS("platform:cpufreq-dt"); 371 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); 372 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); 373 MODULE_DESCRIPTION("Generic cpufreq driver"); 374 MODULE_LICENSE("GPL"); 375