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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 | * | |
95ceafd4 SG |
7 | * The OPP code in function cpu0_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> | |
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 | |
9c0ebcf7 | 38 | static int cpu0_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 | ||
d2f31f1d VK |
109 | static int allocate_resources(struct device **cdev, |
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 | |
e1825b25 SH |
118 | cpu_dev = get_cpu_device(0); |
119 | if (!cpu_dev) { | |
120 | pr_err("failed to get cpu0 device\n"); | |
121 | return -ENODEV; | |
122 | } | |
6754f556 | 123 | |
2d2c5e0e VK |
124 | /* Try "cpu0" for older DTs */ |
125 | reg = reg_cpu0; | |
126 | ||
127 | try_again: | |
128 | cpu_reg = regulator_get_optional(cpu_dev, reg); | |
fc31d6f5 NM |
129 | if (IS_ERR(cpu_reg)) { |
130 | /* | |
131 | * If cpu0 regulator supply node is present, but regulator is | |
132 | * not yet registered, we should try defering probe. | |
133 | */ | |
134 | if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) { | |
713a3fa6 | 135 | dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); |
d2f31f1d | 136 | return -EPROBE_DEFER; |
fc31d6f5 | 137 | } |
2d2c5e0e VK |
138 | |
139 | /* Try with "cpu-supply" */ | |
140 | if (reg == reg_cpu0) { | |
141 | reg = reg_cpu; | |
142 | goto try_again; | |
143 | } | |
144 | ||
fbd48ca5 VK |
145 | dev_warn(cpu_dev, "failed to get cpu0 regulator: %ld\n", |
146 | PTR_ERR(cpu_reg)); | |
fc31d6f5 NM |
147 | } |
148 | ||
e3beb0ac | 149 | cpu_clk = clk_get(cpu_dev, NULL); |
95ceafd4 | 150 | if (IS_ERR(cpu_clk)) { |
d2f31f1d VK |
151 | /* put regulator */ |
152 | if (!IS_ERR(cpu_reg)) | |
153 | regulator_put(cpu_reg); | |
154 | ||
95ceafd4 | 155 | ret = PTR_ERR(cpu_clk); |
48a8624b VK |
156 | |
157 | /* | |
158 | * If cpu's clk node is present, but clock is not yet | |
159 | * registered, we should try defering probe. | |
160 | */ | |
161 | if (ret == -EPROBE_DEFER) | |
162 | dev_dbg(cpu_dev, "cpu0 clock not ready, retry\n"); | |
163 | else | |
164 | dev_err(cpu_dev, "failed to get cpu0 clock: %d\n", ret); | |
d2f31f1d VK |
165 | } else { |
166 | *cdev = cpu_dev; | |
167 | *creg = cpu_reg; | |
168 | *cclk = cpu_clk; | |
169 | } | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | static int cpu0_cpufreq_init(struct cpufreq_policy *policy) | |
175 | { | |
176 | struct cpufreq_frequency_table *freq_table; | |
177 | struct thermal_cooling_device *cdev; | |
178 | struct device_node *np; | |
179 | struct private_data *priv; | |
180 | struct device *cpu_dev; | |
181 | struct regulator *cpu_reg; | |
182 | struct clk *cpu_clk; | |
183 | unsigned int transition_latency; | |
184 | int ret; | |
185 | ||
186 | /* We only support cpu0 currently */ | |
187 | ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk); | |
188 | if (ret) { | |
189 | pr_err("%s: Failed to allocate resources\n: %d", __func__, ret); | |
190 | return ret; | |
191 | } | |
48a8624b | 192 | |
d2f31f1d VK |
193 | np = of_node_get(cpu_dev->of_node); |
194 | if (!np) { | |
195 | dev_err(cpu_dev, "failed to find cpu%d node\n", policy->cpu); | |
196 | ret = -ENOENT; | |
197 | goto out_put_reg_clk; | |
95ceafd4 SG |
198 | } |
199 | ||
1bf8cc3d VK |
200 | /* OPPs might be populated at runtime, don't check for error here */ |
201 | of_init_opp_table(cpu_dev); | |
95ceafd4 | 202 | |
5d4879cd | 203 | ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); |
95ceafd4 | 204 | if (ret) { |
fbd48ca5 | 205 | dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); |
d2f31f1d VK |
206 | goto out_put_node; |
207 | } | |
208 | ||
209 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
210 | if (!priv) { | |
211 | ret = -ENOMEM; | |
212 | goto out_free_table; | |
95ceafd4 SG |
213 | } |
214 | ||
d2f31f1d | 215 | of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance); |
95ceafd4 SG |
216 | |
217 | if (of_property_read_u32(np, "clock-latency", &transition_latency)) | |
218 | transition_latency = CPUFREQ_ETERNAL; | |
219 | ||
43c638e3 | 220 | if (!IS_ERR(cpu_reg)) { |
47d43ba7 | 221 | struct dev_pm_opp *opp; |
95ceafd4 SG |
222 | unsigned long min_uV, max_uV; |
223 | int i; | |
224 | ||
225 | /* | |
226 | * OPP is maintained in order of increasing frequency, and | |
227 | * freq_table initialised from OPP is therefore sorted in the | |
228 | * same order. | |
229 | */ | |
230 | for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) | |
231 | ; | |
78e8eb8f | 232 | rcu_read_lock(); |
5d4879cd | 233 | opp = dev_pm_opp_find_freq_exact(cpu_dev, |
95ceafd4 | 234 | freq_table[0].frequency * 1000, true); |
5d4879cd NM |
235 | min_uV = dev_pm_opp_get_voltage(opp); |
236 | opp = dev_pm_opp_find_freq_exact(cpu_dev, | |
95ceafd4 | 237 | freq_table[i-1].frequency * 1000, true); |
5d4879cd | 238 | max_uV = dev_pm_opp_get_voltage(opp); |
78e8eb8f | 239 | rcu_read_unlock(); |
95ceafd4 SG |
240 | ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV); |
241 | if (ret > 0) | |
242 | transition_latency += ret * 1000; | |
243 | } | |
244 | ||
77cff592 EV |
245 | /* |
246 | * For now, just loading the cooling device; | |
247 | * thermal DT code takes care of matching them. | |
248 | */ | |
249 | if (of_find_property(np, "#cooling-cells", NULL)) { | |
250 | cdev = of_cpufreq_cooling_register(np, cpu_present_mask); | |
251 | if (IS_ERR(cdev)) | |
fbd48ca5 VK |
252 | dev_err(cpu_dev, |
253 | "running cpufreq without cooling device: %ld\n", | |
254 | PTR_ERR(cdev)); | |
d2f31f1d VK |
255 | else |
256 | priv->cdev = cdev; | |
77cff592 | 257 | } |
95ceafd4 | 258 | of_node_put(np); |
d2f31f1d VK |
259 | |
260 | priv->cpu_dev = cpu_dev; | |
261 | priv->cpu_reg = cpu_reg; | |
262 | policy->driver_data = priv; | |
263 | ||
264 | policy->clk = cpu_clk; | |
265 | ret = cpufreq_generic_init(policy, freq_table, transition_latency); | |
266 | if (ret) | |
267 | goto out_cooling_unregister; | |
268 | ||
95ceafd4 SG |
269 | return 0; |
270 | ||
d2f31f1d VK |
271 | out_cooling_unregister: |
272 | cpufreq_cooling_unregister(priv->cdev); | |
273 | kfree(priv); | |
95ceafd4 | 274 | out_free_table: |
5d4879cd | 275 | dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); |
d2f31f1d VK |
276 | out_put_node: |
277 | of_node_put(np); | |
278 | out_put_reg_clk: | |
ed4b053c | 279 | clk_put(cpu_clk); |
e3beb0ac LS |
280 | if (!IS_ERR(cpu_reg)) |
281 | regulator_put(cpu_reg); | |
d2f31f1d VK |
282 | |
283 | return ret; | |
284 | } | |
285 | ||
286 | static int cpu0_cpufreq_exit(struct cpufreq_policy *policy) | |
287 | { | |
288 | struct private_data *priv = policy->driver_data; | |
289 | ||
290 | cpufreq_cooling_unregister(priv->cdev); | |
291 | dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); | |
292 | clk_put(policy->clk); | |
293 | if (!IS_ERR(priv->cpu_reg)) | |
294 | regulator_put(priv->cpu_reg); | |
295 | kfree(priv); | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | static struct cpufreq_driver cpu0_cpufreq_driver = { | |
301 | .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, | |
302 | .verify = cpufreq_generic_frequency_table_verify, | |
303 | .target_index = cpu0_set_target, | |
304 | .get = cpufreq_generic_get, | |
305 | .init = cpu0_cpufreq_init, | |
306 | .exit = cpu0_cpufreq_exit, | |
307 | .name = "generic_cpu0", | |
308 | .attr = cpufreq_generic_attr, | |
309 | }; | |
310 | ||
311 | static int cpu0_cpufreq_probe(struct platform_device *pdev) | |
312 | { | |
313 | struct device *cpu_dev; | |
314 | struct regulator *cpu_reg; | |
315 | struct clk *cpu_clk; | |
316 | int ret; | |
317 | ||
318 | /* | |
319 | * All per-cluster (CPUs sharing clock/voltages) initialization is done | |
320 | * from ->init(). In probe(), we just need to make sure that clk and | |
321 | * regulators are available. Else defer probe and retry. | |
322 | * | |
323 | * FIXME: Is checking this only for CPU0 sufficient ? | |
324 | */ | |
325 | ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk); | |
326 | if (ret) | |
327 | return ret; | |
328 | ||
329 | clk_put(cpu_clk); | |
330 | if (!IS_ERR(cpu_reg)) | |
331 | regulator_put(cpu_reg); | |
332 | ||
333 | ret = cpufreq_register_driver(&cpu0_cpufreq_driver); | |
334 | if (ret) | |
335 | dev_err(cpu_dev, "failed register driver: %d\n", ret); | |
336 | ||
95ceafd4 SG |
337 | return ret; |
338 | } | |
5553f9e2 SG |
339 | |
340 | static int cpu0_cpufreq_remove(struct platform_device *pdev) | |
341 | { | |
342 | cpufreq_unregister_driver(&cpu0_cpufreq_driver); | |
5553f9e2 SG |
343 | return 0; |
344 | } | |
345 | ||
346 | static struct platform_driver cpu0_cpufreq_platdrv = { | |
347 | .driver = { | |
348 | .name = "cpufreq-cpu0", | |
349 | .owner = THIS_MODULE, | |
350 | }, | |
351 | .probe = cpu0_cpufreq_probe, | |
352 | .remove = cpu0_cpufreq_remove, | |
353 | }; | |
354 | module_platform_driver(cpu0_cpufreq_platdrv); | |
95ceafd4 | 355 | |
748c8766 | 356 | MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); |
95ceafd4 SG |
357 | MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); |
358 | MODULE_DESCRIPTION("Generic CPU0 cpufreq driver"); | |
359 | MODULE_LICENSE("GPL"); |