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, cpumask: 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(dev: priv->cpu_dev, target_freq: 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(node: 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, name: "cpu0-supply" , NULL); |
85 | if (pp) { |
86 | name = "cpu0" ; |
87 | goto node_put; |
88 | } |
89 | } |
90 | |
91 | pp = of_find_property(np, name: "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(node: 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(cpu: 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(dev: cpu_dev, NULL); |
119 | if (IS_ERR(ptr: cpu_clk)) { |
120 | ret = PTR_ERR(ptr: 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(dev: cpu_dev); |
126 | if (!transition_latency) |
127 | transition_latency = CPUFREQ_ETERNAL; |
128 | |
129 | cpumask_copy(dstp: policy->cpus, srcp: 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(dev: 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(clk: 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(clk: 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, size: sizeof(*priv), GFP_KERNEL); |
208 | if (!priv) |
209 | return -ENOMEM; |
210 | |
211 | if (!zalloc_cpumask_var(mask: &priv->cpus, GFP_KERNEL)) |
212 | return -ENOMEM; |
213 | |
214 | cpumask_set_cpu(cpu, dstp: 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(dev: cpu_dev); |
222 | if (reg_name[0]) { |
223 | priv->opp_token = dev_pm_opp_set_regulators(dev: cpu_dev, names: reg_name); |
224 | if (priv->opp_token < 0) { |
225 | ret = dev_err_probe(dev: cpu_dev, err: priv->opp_token, |
226 | fmt: "failed to set regulators\n" ); |
227 | goto free_cpumask; |
228 | } |
229 | } |
230 | |
231 | /* Get OPP-sharing information from "operating-points-v2" bindings */ |
232 | ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, cpumask: priv->cpus); |
233 | if (ret) { |
234 | if (ret != -ENOENT) |
235 | goto out; |
236 | |
237 | /* |
238 | * operating-points-v2 not supported, fallback to all CPUs share |
239 | * OPP for backward compatibility if the platform hasn't set |
240 | * sharing CPUs. |
241 | */ |
242 | if (dev_pm_opp_get_sharing_cpus(cpu_dev, cpumask: priv->cpus)) |
243 | fallback = true; |
244 | } |
245 | |
246 | /* |
247 | * Initialize OPP tables for all priv->cpus. They will be shared by |
248 | * all CPUs which have marked their CPUs shared with OPP bindings. |
249 | * |
250 | * For platforms not using operating-points-v2 bindings, we do this |
251 | * before updating priv->cpus. Otherwise, we will end up creating |
252 | * duplicate OPPs for the CPUs. |
253 | * |
254 | * OPPs might be populated at runtime, don't fail for error here unless |
255 | * it is -EPROBE_DEFER. |
256 | */ |
257 | ret = dev_pm_opp_of_cpumask_add_table(cpumask: priv->cpus); |
258 | if (!ret) { |
259 | priv->have_static_opps = true; |
260 | } else if (ret == -EPROBE_DEFER) { |
261 | goto out; |
262 | } |
263 | |
264 | /* |
265 | * The OPP table must be initialized, statically or dynamically, by this |
266 | * point. |
267 | */ |
268 | ret = dev_pm_opp_get_opp_count(dev: cpu_dev); |
269 | if (ret <= 0) { |
270 | dev_err(cpu_dev, "OPP table can't be empty\n" ); |
271 | ret = -ENODEV; |
272 | goto out; |
273 | } |
274 | |
275 | if (fallback) { |
276 | cpumask_setall(dstp: priv->cpus); |
277 | ret = dev_pm_opp_set_sharing_cpus(cpu_dev, cpumask: priv->cpus); |
278 | if (ret) |
279 | dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n" , |
280 | __func__, ret); |
281 | } |
282 | |
283 | ret = dev_pm_opp_init_cpufreq_table(dev: cpu_dev, table: &priv->freq_table); |
284 | if (ret) { |
285 | dev_err(cpu_dev, "failed to init cpufreq table: %d\n" , ret); |
286 | goto out; |
287 | } |
288 | |
289 | list_add(new: &priv->node, head: &priv_list); |
290 | return 0; |
291 | |
292 | out: |
293 | if (priv->have_static_opps) |
294 | dev_pm_opp_of_cpumask_remove_table(cpumask: priv->cpus); |
295 | dev_pm_opp_put_regulators(token: priv->opp_token); |
296 | free_cpumask: |
297 | free_cpumask_var(mask: priv->cpus); |
298 | return ret; |
299 | } |
300 | |
301 | static void dt_cpufreq_release(void) |
302 | { |
303 | struct private_data *priv, *tmp; |
304 | |
305 | list_for_each_entry_safe(priv, tmp, &priv_list, node) { |
306 | dev_pm_opp_free_cpufreq_table(dev: priv->cpu_dev, table: &priv->freq_table); |
307 | if (priv->have_static_opps) |
308 | dev_pm_opp_of_cpumask_remove_table(cpumask: priv->cpus); |
309 | dev_pm_opp_put_regulators(token: priv->opp_token); |
310 | free_cpumask_var(mask: priv->cpus); |
311 | list_del(entry: &priv->node); |
312 | } |
313 | } |
314 | |
315 | static int dt_cpufreq_probe(struct platform_device *pdev) |
316 | { |
317 | struct cpufreq_dt_platform_data *data = dev_get_platdata(dev: &pdev->dev); |
318 | int ret, cpu; |
319 | |
320 | /* Request resources early so we can return in case of -EPROBE_DEFER */ |
321 | for_each_possible_cpu(cpu) { |
322 | ret = dt_cpufreq_early_init(dev: &pdev->dev, cpu); |
323 | if (ret) |
324 | goto err; |
325 | } |
326 | |
327 | if (data) { |
328 | if (data->have_governor_per_policy) |
329 | dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; |
330 | |
331 | dt_cpufreq_driver.resume = data->resume; |
332 | if (data->suspend) |
333 | dt_cpufreq_driver.suspend = data->suspend; |
334 | if (data->get_intermediate) { |
335 | dt_cpufreq_driver.target_intermediate = data->target_intermediate; |
336 | dt_cpufreq_driver.get_intermediate = data->get_intermediate; |
337 | } |
338 | } |
339 | |
340 | ret = cpufreq_register_driver(driver_data: &dt_cpufreq_driver); |
341 | if (ret) { |
342 | dev_err(&pdev->dev, "failed register driver: %d\n" , ret); |
343 | goto err; |
344 | } |
345 | |
346 | return 0; |
347 | err: |
348 | dt_cpufreq_release(); |
349 | return ret; |
350 | } |
351 | |
352 | static void dt_cpufreq_remove(struct platform_device *pdev) |
353 | { |
354 | cpufreq_unregister_driver(driver_data: &dt_cpufreq_driver); |
355 | dt_cpufreq_release(); |
356 | } |
357 | |
358 | static struct platform_driver dt_cpufreq_platdrv = { |
359 | .driver = { |
360 | .name = "cpufreq-dt" , |
361 | }, |
362 | .probe = dt_cpufreq_probe, |
363 | .remove_new = dt_cpufreq_remove, |
364 | }; |
365 | module_platform_driver(dt_cpufreq_platdrv); |
366 | |
367 | MODULE_ALIAS("platform:cpufreq-dt" ); |
368 | MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>" ); |
369 | MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>" ); |
370 | MODULE_DESCRIPTION("Generic cpufreq driver" ); |
371 | MODULE_LICENSE("GPL" ); |
372 | |