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cpufreq: cpu0: try regulators with name "cpu-supply"
[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / cpufreq-cpu0.c
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95ceafd4
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1/*
2 * Copyright (C) 2012 Freescale Semiconductor, Inc.
3 *
748c8766
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4 * Copyright (C) 2014 Linaro.
5 * Viresh Kumar <viresh.kumar@linaro.org>
6 *
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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>
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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>
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27#include <linux/regulator/consumer.h>
28#include <linux/slab.h>
77cff592 29#include <linux/thermal.h>
95ceafd4 30
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31struct 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 38static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
95ceafd4 39{
47d43ba7 40 struct dev_pm_opp *opp;
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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;
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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
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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();
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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;
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71 volt_old = regulator_get_voltage(cpu_reg);
72 }
73
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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);
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77
78 /* scaling up? scale voltage before frequency */
d4019f0a 79 if (!IS_ERR(cpu_reg) && new_freq > old_freq) {
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80 ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
81 if (ret) {
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82 dev_err(cpu_dev, "failed to scale voltage up: %d\n",
83 ret);
d4019f0a 84 return ret;
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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;
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94 }
95
96 /* scaling down? scale voltage after frequency */
d4019f0a 97 if (!IS_ERR(cpu_reg) && new_freq < old_freq) {
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98 ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
99 if (ret) {
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100 dev_err(cpu_dev, "failed to scale voltage down: %d\n",
101 ret);
d4019f0a 102 clk_set_rate(cpu_clk, old_freq * 1000);
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103 }
104 }
105
fd143b4d 106 return ret;
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107}
108
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109static int allocate_resources(struct device **cdev,
110 struct regulator **creg, struct clk **cclk)
95ceafd4 111{
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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
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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
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124 /* Try "cpu0" for older DTs */
125 reg = reg_cpu0;
126
127try_again:
128 cpu_reg = regulator_get_optional(cpu_dev, reg);
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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 }
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138
139 /* Try with "cpu-supply" */
140 if (reg == reg_cpu0) {
141 reg = reg_cpu;
142 goto try_again;
143 }
144
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145 dev_warn(cpu_dev, "failed to get cpu0 regulator: %ld\n",
146 PTR_ERR(cpu_reg));
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147 }
148
e3beb0ac 149 cpu_clk = clk_get(cpu_dev, NULL);
95ceafd4 150 if (IS_ERR(cpu_clk)) {
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151 /* put regulator */
152 if (!IS_ERR(cpu_reg))
153 regulator_put(cpu_reg);
154
95ceafd4 155 ret = PTR_ERR(cpu_clk);
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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);
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165 } else {
166 *cdev = cpu_dev;
167 *creg = cpu_reg;
168 *cclk = cpu_clk;
169 }
170
171 return ret;
172}
173
174static 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
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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;
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198 }
199
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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);
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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;
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213 }
214
d2f31f1d 215 of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance);
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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;
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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);
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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();
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240 ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
241 if (ret > 0)
242 transition_latency += ret * 1000;
243 }
244
77cff592
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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))
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252 dev_err(cpu_dev,
253 "running cpufreq without cooling device: %ld\n",
254 PTR_ERR(cdev));
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255 else
256 priv->cdev = cdev;
77cff592 257 }
95ceafd4 258 of_node_put(np);
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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
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269 return 0;
270
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271out_cooling_unregister:
272 cpufreq_cooling_unregister(priv->cdev);
273 kfree(priv);
95ceafd4 274out_free_table:
5d4879cd 275 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
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276out_put_node:
277 of_node_put(np);
278out_put_reg_clk:
ed4b053c 279 clk_put(cpu_clk);
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LS
280 if (!IS_ERR(cpu_reg))
281 regulator_put(cpu_reg);
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282
283 return ret;
284}
285
286static 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
300static 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
311static 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
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337 return ret;
338}
5553f9e2
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339
340static int cpu0_cpufreq_remove(struct platform_device *pdev)
341{
342 cpufreq_unregister_driver(&cpu0_cpufreq_driver);
5553f9e2
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343 return 0;
344}
345
346static 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};
354module_platform_driver(cpu0_cpufreq_platdrv);
95ceafd4 355
748c8766 356MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
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357MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
358MODULE_DESCRIPTION("Generic CPU0 cpufreq driver");
359MODULE_LICENSE("GPL");