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Commit | Line | Data |
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95ceafd4 SG |
1 | /* |
2 | * Copyright (C) 2012 Freescale Semiconductor, Inc. | |
3 | * | |
748c8766 VK |
4 | * Copyright (C) 2014 Linaro. |
5 | * Viresh Kumar <viresh.kumar@linaro.org> | |
6 | * | |
bbcf0719 | 7 | * The OPP code in function set_target() is reused from |
95ceafd4 SG |
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> | |
e1825b25 | 18 | #include <linux/cpu.h> |
77cff592 | 19 | #include <linux/cpu_cooling.h> |
95ceafd4 | 20 | #include <linux/cpufreq.h> |
34e5a527 | 21 | #include <linux/cpufreq-dt.h> |
77cff592 | 22 | #include <linux/cpumask.h> |
95ceafd4 SG |
23 | #include <linux/err.h> |
24 | #include <linux/module.h> | |
25 | #include <linux/of.h> | |
e4db1c74 | 26 | #include <linux/pm_opp.h> |
5553f9e2 | 27 | #include <linux/platform_device.h> |
95ceafd4 SG |
28 | #include <linux/regulator/consumer.h> |
29 | #include <linux/slab.h> | |
77cff592 | 30 | #include <linux/thermal.h> |
95ceafd4 | 31 | |
d2f31f1d VK |
32 | struct private_data { |
33 | struct device *cpu_dev; | |
34 | struct regulator *cpu_reg; | |
35 | struct thermal_cooling_device *cdev; | |
36 | unsigned int voltage_tolerance; /* in percentage */ | |
37 | }; | |
95ceafd4 | 38 | |
bbcf0719 | 39 | static int set_target(struct cpufreq_policy *policy, unsigned int index) |
95ceafd4 | 40 | { |
47d43ba7 | 41 | struct dev_pm_opp *opp; |
d2f31f1d VK |
42 | struct cpufreq_frequency_table *freq_table = policy->freq_table; |
43 | struct clk *cpu_clk = policy->clk; | |
44 | struct private_data *priv = policy->driver_data; | |
45 | struct device *cpu_dev = priv->cpu_dev; | |
46 | struct regulator *cpu_reg = priv->cpu_reg; | |
5df60559 | 47 | unsigned long volt = 0, volt_old = 0, tol = 0; |
d4019f0a | 48 | unsigned int old_freq, new_freq; |
0ca68436 | 49 | long freq_Hz, freq_exact; |
95ceafd4 SG |
50 | int ret; |
51 | ||
95ceafd4 | 52 | freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000); |
2209b0c9 | 53 | if (freq_Hz <= 0) |
95ceafd4 | 54 | freq_Hz = freq_table[index].frequency * 1000; |
95ceafd4 | 55 | |
d4019f0a VK |
56 | freq_exact = freq_Hz; |
57 | new_freq = freq_Hz / 1000; | |
58 | old_freq = clk_get_rate(cpu_clk) / 1000; | |
95ceafd4 | 59 | |
4a511de9 | 60 | if (!IS_ERR(cpu_reg)) { |
0a1e879d SW |
61 | unsigned long opp_freq; |
62 | ||
78e8eb8f | 63 | rcu_read_lock(); |
5d4879cd | 64 | opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz); |
95ceafd4 | 65 | if (IS_ERR(opp)) { |
78e8eb8f | 66 | rcu_read_unlock(); |
fbd48ca5 VK |
67 | dev_err(cpu_dev, "failed to find OPP for %ld\n", |
68 | freq_Hz); | |
d4019f0a | 69 | return PTR_ERR(opp); |
95ceafd4 | 70 | } |
5d4879cd | 71 | volt = dev_pm_opp_get_voltage(opp); |
0a1e879d | 72 | opp_freq = dev_pm_opp_get_freq(opp); |
78e8eb8f | 73 | rcu_read_unlock(); |
d2f31f1d | 74 | tol = volt * priv->voltage_tolerance / 100; |
95ceafd4 | 75 | volt_old = regulator_get_voltage(cpu_reg); |
0a1e879d SW |
76 | dev_dbg(cpu_dev, "Found OPP: %ld kHz, %ld uV\n", |
77 | opp_freq / 1000, volt); | |
95ceafd4 SG |
78 | } |
79 | ||
fbd48ca5 | 80 | dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n", |
8197bb1b | 81 | old_freq / 1000, (volt_old > 0) ? volt_old / 1000 : -1, |
fbd48ca5 | 82 | new_freq / 1000, volt ? volt / 1000 : -1); |
95ceafd4 SG |
83 | |
84 | /* scaling up? scale voltage before frequency */ | |
d4019f0a | 85 | if (!IS_ERR(cpu_reg) && new_freq > old_freq) { |
95ceafd4 SG |
86 | ret = regulator_set_voltage_tol(cpu_reg, volt, tol); |
87 | if (ret) { | |
fbd48ca5 VK |
88 | dev_err(cpu_dev, "failed to scale voltage up: %d\n", |
89 | ret); | |
d4019f0a | 90 | return ret; |
95ceafd4 SG |
91 | } |
92 | } | |
93 | ||
0ca68436 | 94 | ret = clk_set_rate(cpu_clk, freq_exact); |
95ceafd4 | 95 | if (ret) { |
fbd48ca5 | 96 | dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); |
8197bb1b | 97 | if (!IS_ERR(cpu_reg) && volt_old > 0) |
95ceafd4 | 98 | regulator_set_voltage_tol(cpu_reg, volt_old, tol); |
d4019f0a | 99 | return ret; |
95ceafd4 SG |
100 | } |
101 | ||
102 | /* scaling down? scale voltage after frequency */ | |
d4019f0a | 103 | if (!IS_ERR(cpu_reg) && new_freq < old_freq) { |
95ceafd4 SG |
104 | ret = regulator_set_voltage_tol(cpu_reg, volt, tol); |
105 | if (ret) { | |
fbd48ca5 VK |
106 | dev_err(cpu_dev, "failed to scale voltage down: %d\n", |
107 | ret); | |
d4019f0a | 108 | clk_set_rate(cpu_clk, old_freq * 1000); |
95ceafd4 SG |
109 | } |
110 | } | |
111 | ||
fd143b4d | 112 | return ret; |
95ceafd4 SG |
113 | } |
114 | ||
95b61058 | 115 | static int allocate_resources(int cpu, struct device **cdev, |
d2f31f1d | 116 | struct regulator **creg, struct clk **cclk) |
95ceafd4 | 117 | { |
d2f31f1d VK |
118 | struct device *cpu_dev; |
119 | struct regulator *cpu_reg; | |
120 | struct clk *cpu_clk; | |
121 | int ret = 0; | |
2d2c5e0e | 122 | char *reg_cpu0 = "cpu0", *reg_cpu = "cpu", *reg; |
95ceafd4 | 123 | |
95b61058 | 124 | cpu_dev = get_cpu_device(cpu); |
e1825b25 | 125 | if (!cpu_dev) { |
95b61058 | 126 | pr_err("failed to get cpu%d device\n", cpu); |
e1825b25 SH |
127 | return -ENODEV; |
128 | } | |
6754f556 | 129 | |
2d2c5e0e | 130 | /* Try "cpu0" for older DTs */ |
95b61058 VK |
131 | if (!cpu) |
132 | reg = reg_cpu0; | |
133 | else | |
134 | reg = reg_cpu; | |
2d2c5e0e VK |
135 | |
136 | try_again: | |
137 | cpu_reg = regulator_get_optional(cpu_dev, reg); | |
fc31d6f5 NM |
138 | if (IS_ERR(cpu_reg)) { |
139 | /* | |
95b61058 | 140 | * If cpu's regulator supply node is present, but regulator is |
fc31d6f5 NM |
141 | * not yet registered, we should try defering probe. |
142 | */ | |
143 | if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) { | |
95b61058 VK |
144 | dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n", |
145 | cpu); | |
d2f31f1d | 146 | return -EPROBE_DEFER; |
fc31d6f5 | 147 | } |
2d2c5e0e VK |
148 | |
149 | /* Try with "cpu-supply" */ | |
150 | if (reg == reg_cpu0) { | |
151 | reg = reg_cpu; | |
152 | goto try_again; | |
153 | } | |
154 | ||
a00de1ab TP |
155 | dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n", |
156 | cpu, PTR_ERR(cpu_reg)); | |
fc31d6f5 NM |
157 | } |
158 | ||
e3beb0ac | 159 | cpu_clk = clk_get(cpu_dev, NULL); |
95ceafd4 | 160 | if (IS_ERR(cpu_clk)) { |
d2f31f1d VK |
161 | /* put regulator */ |
162 | if (!IS_ERR(cpu_reg)) | |
163 | regulator_put(cpu_reg); | |
164 | ||
95ceafd4 | 165 | ret = PTR_ERR(cpu_clk); |
48a8624b VK |
166 | |
167 | /* | |
168 | * If cpu's clk node is present, but clock is not yet | |
169 | * registered, we should try defering probe. | |
170 | */ | |
171 | if (ret == -EPROBE_DEFER) | |
95b61058 | 172 | dev_dbg(cpu_dev, "cpu%d clock not ready, retry\n", cpu); |
48a8624b | 173 | else |
71796210 AK |
174 | dev_err(cpu_dev, "failed to get cpu%d clock: %d\n", cpu, |
175 | ret); | |
d2f31f1d VK |
176 | } else { |
177 | *cdev = cpu_dev; | |
178 | *creg = cpu_reg; | |
179 | *cclk = cpu_clk; | |
180 | } | |
181 | ||
182 | return ret; | |
183 | } | |
184 | ||
bbcf0719 | 185 | static int cpufreq_init(struct cpufreq_policy *policy) |
d2f31f1d | 186 | { |
34e5a527 | 187 | struct cpufreq_dt_platform_data *pd; |
d2f31f1d VK |
188 | struct cpufreq_frequency_table *freq_table; |
189 | struct thermal_cooling_device *cdev; | |
190 | struct device_node *np; | |
191 | struct private_data *priv; | |
192 | struct device *cpu_dev; | |
193 | struct regulator *cpu_reg; | |
194 | struct clk *cpu_clk; | |
045ee45c | 195 | unsigned long min_uV = ~0, max_uV = 0; |
d2f31f1d VK |
196 | unsigned int transition_latency; |
197 | int ret; | |
198 | ||
95b61058 | 199 | ret = allocate_resources(policy->cpu, &cpu_dev, &cpu_reg, &cpu_clk); |
d2f31f1d VK |
200 | if (ret) { |
201 | pr_err("%s: Failed to allocate resources\n: %d", __func__, ret); | |
202 | return ret; | |
203 | } | |
48a8624b | 204 | |
d2f31f1d VK |
205 | np = of_node_get(cpu_dev->of_node); |
206 | if (!np) { | |
207 | dev_err(cpu_dev, "failed to find cpu%d node\n", policy->cpu); | |
208 | ret = -ENOENT; | |
209 | goto out_put_reg_clk; | |
95ceafd4 SG |
210 | } |
211 | ||
1bf8cc3d VK |
212 | /* OPPs might be populated at runtime, don't check for error here */ |
213 | of_init_opp_table(cpu_dev); | |
95ceafd4 | 214 | |
d2f31f1d VK |
215 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
216 | if (!priv) { | |
217 | ret = -ENOMEM; | |
045ee45c | 218 | goto out_put_node; |
95ceafd4 SG |
219 | } |
220 | ||
d2f31f1d | 221 | of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance); |
95ceafd4 SG |
222 | |
223 | if (of_property_read_u32(np, "clock-latency", &transition_latency)) | |
224 | transition_latency = CPUFREQ_ETERNAL; | |
225 | ||
43c638e3 | 226 | if (!IS_ERR(cpu_reg)) { |
045ee45c | 227 | unsigned long opp_freq = 0; |
95ceafd4 SG |
228 | |
229 | /* | |
045ee45c LS |
230 | * Disable any OPPs where the connected regulator isn't able to |
231 | * provide the specified voltage and record minimum and maximum | |
232 | * voltage levels. | |
95ceafd4 | 233 | */ |
045ee45c LS |
234 | while (1) { |
235 | struct dev_pm_opp *opp; | |
236 | unsigned long opp_uV, tol_uV; | |
237 | ||
238 | rcu_read_lock(); | |
239 | opp = dev_pm_opp_find_freq_ceil(cpu_dev, &opp_freq); | |
240 | if (IS_ERR(opp)) { | |
241 | rcu_read_unlock(); | |
242 | break; | |
243 | } | |
244 | opp_uV = dev_pm_opp_get_voltage(opp); | |
245 | rcu_read_unlock(); | |
246 | ||
247 | tol_uV = opp_uV * priv->voltage_tolerance / 100; | |
248 | if (regulator_is_supported_voltage(cpu_reg, opp_uV, | |
249 | opp_uV + tol_uV)) { | |
250 | if (opp_uV < min_uV) | |
251 | min_uV = opp_uV; | |
252 | if (opp_uV > max_uV) | |
253 | max_uV = opp_uV; | |
254 | } else { | |
255 | dev_pm_opp_disable(cpu_dev, opp_freq); | |
256 | } | |
257 | ||
258 | opp_freq++; | |
259 | } | |
260 | ||
95ceafd4 SG |
261 | ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV); |
262 | if (ret > 0) | |
263 | transition_latency += ret * 1000; | |
264 | } | |
265 | ||
045ee45c LS |
266 | ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); |
267 | if (ret) { | |
268 | pr_err("failed to init cpufreq table: %d\n", ret); | |
269 | goto out_free_priv; | |
270 | } | |
271 | ||
77cff592 EV |
272 | /* |
273 | * For now, just loading the cooling device; | |
274 | * thermal DT code takes care of matching them. | |
275 | */ | |
276 | if (of_find_property(np, "#cooling-cells", NULL)) { | |
d3a10c14 | 277 | cdev = of_cpufreq_cooling_register(np, policy->related_cpus); |
77cff592 | 278 | if (IS_ERR(cdev)) |
fbd48ca5 VK |
279 | dev_err(cpu_dev, |
280 | "running cpufreq without cooling device: %ld\n", | |
281 | PTR_ERR(cdev)); | |
d2f31f1d VK |
282 | else |
283 | priv->cdev = cdev; | |
77cff592 | 284 | } |
d2f31f1d VK |
285 | |
286 | priv->cpu_dev = cpu_dev; | |
287 | priv->cpu_reg = cpu_reg; | |
288 | policy->driver_data = priv; | |
289 | ||
290 | policy->clk = cpu_clk; | |
34e5a527 TP |
291 | ret = cpufreq_table_validate_and_show(policy, freq_table); |
292 | if (ret) { | |
293 | dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, | |
294 | ret); | |
d2f31f1d | 295 | goto out_cooling_unregister; |
34e5a527 TP |
296 | } |
297 | ||
298 | policy->cpuinfo.transition_latency = transition_latency; | |
299 | ||
300 | pd = cpufreq_get_driver_data(); | |
c81407fe | 301 | if (!pd || !pd->independent_clocks) |
34e5a527 | 302 | cpumask_setall(policy->cpus); |
d2f31f1d | 303 | |
f9739d27 LS |
304 | of_node_put(np); |
305 | ||
95ceafd4 SG |
306 | return 0; |
307 | ||
d2f31f1d VK |
308 | out_cooling_unregister: |
309 | cpufreq_cooling_unregister(priv->cdev); | |
5d4879cd | 310 | dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); |
045ee45c LS |
311 | out_free_priv: |
312 | kfree(priv); | |
d2f31f1d VK |
313 | out_put_node: |
314 | of_node_put(np); | |
315 | out_put_reg_clk: | |
ed4b053c | 316 | clk_put(cpu_clk); |
e3beb0ac LS |
317 | if (!IS_ERR(cpu_reg)) |
318 | regulator_put(cpu_reg); | |
d2f31f1d VK |
319 | |
320 | return ret; | |
321 | } | |
322 | ||
bbcf0719 | 323 | static int cpufreq_exit(struct cpufreq_policy *policy) |
d2f31f1d VK |
324 | { |
325 | struct private_data *priv = policy->driver_data; | |
326 | ||
327 | cpufreq_cooling_unregister(priv->cdev); | |
328 | dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); | |
329 | clk_put(policy->clk); | |
330 | if (!IS_ERR(priv->cpu_reg)) | |
331 | regulator_put(priv->cpu_reg); | |
332 | kfree(priv); | |
333 | ||
334 | return 0; | |
335 | } | |
336 | ||
bbcf0719 | 337 | static struct cpufreq_driver dt_cpufreq_driver = { |
d2f31f1d VK |
338 | .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, |
339 | .verify = cpufreq_generic_frequency_table_verify, | |
bbcf0719 | 340 | .target_index = set_target, |
d2f31f1d | 341 | .get = cpufreq_generic_get, |
bbcf0719 VK |
342 | .init = cpufreq_init, |
343 | .exit = cpufreq_exit, | |
344 | .name = "cpufreq-dt", | |
d2f31f1d VK |
345 | .attr = cpufreq_generic_attr, |
346 | }; | |
347 | ||
bbcf0719 | 348 | static int dt_cpufreq_probe(struct platform_device *pdev) |
d2f31f1d VK |
349 | { |
350 | struct device *cpu_dev; | |
351 | struct regulator *cpu_reg; | |
352 | struct clk *cpu_clk; | |
353 | int ret; | |
354 | ||
355 | /* | |
356 | * All per-cluster (CPUs sharing clock/voltages) initialization is done | |
357 | * from ->init(). In probe(), we just need to make sure that clk and | |
358 | * regulators are available. Else defer probe and retry. | |
359 | * | |
360 | * FIXME: Is checking this only for CPU0 sufficient ? | |
361 | */ | |
95b61058 | 362 | ret = allocate_resources(0, &cpu_dev, &cpu_reg, &cpu_clk); |
d2f31f1d VK |
363 | if (ret) |
364 | return ret; | |
365 | ||
366 | clk_put(cpu_clk); | |
367 | if (!IS_ERR(cpu_reg)) | |
368 | regulator_put(cpu_reg); | |
369 | ||
34e5a527 TP |
370 | dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev); |
371 | ||
bbcf0719 | 372 | ret = cpufreq_register_driver(&dt_cpufreq_driver); |
d2f31f1d VK |
373 | if (ret) |
374 | dev_err(cpu_dev, "failed register driver: %d\n", ret); | |
375 | ||
95ceafd4 SG |
376 | return ret; |
377 | } | |
5553f9e2 | 378 | |
bbcf0719 | 379 | static int dt_cpufreq_remove(struct platform_device *pdev) |
5553f9e2 | 380 | { |
bbcf0719 | 381 | cpufreq_unregister_driver(&dt_cpufreq_driver); |
5553f9e2 SG |
382 | return 0; |
383 | } | |
384 | ||
bbcf0719 | 385 | static struct platform_driver dt_cpufreq_platdrv = { |
5553f9e2 | 386 | .driver = { |
bbcf0719 | 387 | .name = "cpufreq-dt", |
5553f9e2 SG |
388 | .owner = THIS_MODULE, |
389 | }, | |
bbcf0719 VK |
390 | .probe = dt_cpufreq_probe, |
391 | .remove = dt_cpufreq_remove, | |
5553f9e2 | 392 | }; |
bbcf0719 | 393 | module_platform_driver(dt_cpufreq_platdrv); |
95ceafd4 | 394 | |
748c8766 | 395 | MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); |
95ceafd4 | 396 | MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); |
bbcf0719 | 397 | MODULE_DESCRIPTION("Generic cpufreq driver"); |
95ceafd4 | 398 | MODULE_LICENSE("GPL"); |