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