GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / cpufreq / mediatek-cpufreq.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 Linaro Ltd.
4  * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
5  */
6
7 #include <linux/clk.h>
8 #include <linux/cpu.h>
9 #include <linux/cpufreq.h>
10 #include <linux/cpumask.h>
11 #include <linux/minmax.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_platform.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_opp.h>
17 #include <linux/regulator/consumer.h>
18
19 struct mtk_cpufreq_platform_data {
20         int min_volt_shift;
21         int max_volt_shift;
22         int proc_max_volt;
23         int sram_min_volt;
24         int sram_max_volt;
25         bool ccifreq_supported;
26 };
27
28 /*
29  * The struct mtk_cpu_dvfs_info holds necessary information for doing CPU DVFS
30  * on each CPU power/clock domain of Mediatek SoCs. Each CPU cluster in
31  * Mediatek SoCs has two voltage inputs, Vproc and Vsram. In some cases the two
32  * voltage inputs need to be controlled under a hardware limitation:
33  * 100mV < Vsram - Vproc < 200mV
34  *
35  * When scaling the clock frequency of a CPU clock domain, the clock source
36  * needs to be switched to another stable PLL clock temporarily until
37  * the original PLL becomes stable at target frequency.
38  */
39 struct mtk_cpu_dvfs_info {
40         struct cpumask cpus;
41         struct device *cpu_dev;
42         struct device *cci_dev;
43         struct regulator *proc_reg;
44         struct regulator *sram_reg;
45         struct clk *cpu_clk;
46         struct clk *inter_clk;
47         struct list_head list_head;
48         int intermediate_voltage;
49         bool need_voltage_tracking;
50         int vproc_on_boot;
51         int pre_vproc;
52         /* Avoid race condition for regulators between notify and policy */
53         struct mutex reg_lock;
54         struct notifier_block opp_nb;
55         unsigned int opp_cpu;
56         unsigned long current_freq;
57         const struct mtk_cpufreq_platform_data *soc_data;
58         int vtrack_max;
59         bool ccifreq_bound;
60 };
61
62 static struct platform_device *cpufreq_pdev;
63
64 static LIST_HEAD(dvfs_info_list);
65
66 static struct mtk_cpu_dvfs_info *mtk_cpu_dvfs_info_lookup(int cpu)
67 {
68         struct mtk_cpu_dvfs_info *info;
69
70         list_for_each_entry(info, &dvfs_info_list, list_head) {
71                 if (cpumask_test_cpu(cpu, &info->cpus))
72                         return info;
73         }
74
75         return NULL;
76 }
77
78 static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
79                                         int new_vproc)
80 {
81         const struct mtk_cpufreq_platform_data *soc_data = info->soc_data;
82         struct regulator *proc_reg = info->proc_reg;
83         struct regulator *sram_reg = info->sram_reg;
84         int pre_vproc, pre_vsram, new_vsram, vsram, vproc, ret;
85         int retry = info->vtrack_max;
86
87         pre_vproc = regulator_get_voltage(proc_reg);
88         if (pre_vproc < 0) {
89                 dev_err(info->cpu_dev,
90                         "invalid Vproc value: %d\n", pre_vproc);
91                 return pre_vproc;
92         }
93
94         pre_vsram = regulator_get_voltage(sram_reg);
95         if (pre_vsram < 0) {
96                 dev_err(info->cpu_dev, "invalid Vsram value: %d\n", pre_vsram);
97                 return pre_vsram;
98         }
99
100         new_vsram = clamp(new_vproc + soc_data->min_volt_shift,
101                           soc_data->sram_min_volt, soc_data->sram_max_volt);
102
103         do {
104                 if (pre_vproc <= new_vproc) {
105                         vsram = clamp(pre_vproc + soc_data->max_volt_shift,
106                                       soc_data->sram_min_volt, new_vsram);
107                         ret = regulator_set_voltage(sram_reg, vsram,
108                                                     soc_data->sram_max_volt);
109
110                         if (ret)
111                                 return ret;
112
113                         if (vsram == soc_data->sram_max_volt ||
114                             new_vsram == soc_data->sram_min_volt)
115                                 vproc = new_vproc;
116                         else
117                                 vproc = vsram - soc_data->min_volt_shift;
118
119                         ret = regulator_set_voltage(proc_reg, vproc,
120                                                     soc_data->proc_max_volt);
121                         if (ret) {
122                                 regulator_set_voltage(sram_reg, pre_vsram,
123                                                       soc_data->sram_max_volt);
124                                 return ret;
125                         }
126                 } else if (pre_vproc > new_vproc) {
127                         vproc = max(new_vproc,
128                                     pre_vsram - soc_data->max_volt_shift);
129                         ret = regulator_set_voltage(proc_reg, vproc,
130                                                     soc_data->proc_max_volt);
131                         if (ret)
132                                 return ret;
133
134                         if (vproc == new_vproc)
135                                 vsram = new_vsram;
136                         else
137                                 vsram = max(new_vsram,
138                                             vproc + soc_data->min_volt_shift);
139
140                         ret = regulator_set_voltage(sram_reg, vsram,
141                                                     soc_data->sram_max_volt);
142                         if (ret) {
143                                 regulator_set_voltage(proc_reg, pre_vproc,
144                                                       soc_data->proc_max_volt);
145                                 return ret;
146                         }
147                 }
148
149                 pre_vproc = vproc;
150                 pre_vsram = vsram;
151
152                 if (--retry < 0) {
153                         dev_err(info->cpu_dev,
154                                 "over loop count, failed to set voltage\n");
155                         return -EINVAL;
156                 }
157         } while (vproc != new_vproc || vsram != new_vsram);
158
159         return 0;
160 }
161
162 static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
163 {
164         const struct mtk_cpufreq_platform_data *soc_data = info->soc_data;
165         int ret;
166
167         if (info->need_voltage_tracking)
168                 ret = mtk_cpufreq_voltage_tracking(info, vproc);
169         else
170                 ret = regulator_set_voltage(info->proc_reg, vproc,
171                                             soc_data->proc_max_volt);
172         if (!ret)
173                 info->pre_vproc = vproc;
174
175         return ret;
176 }
177
178 static bool is_ccifreq_ready(struct mtk_cpu_dvfs_info *info)
179 {
180         struct device_link *sup_link;
181
182         if (info->ccifreq_bound)
183                 return true;
184
185         sup_link = device_link_add(info->cpu_dev, info->cci_dev,
186                                    DL_FLAG_AUTOREMOVE_CONSUMER);
187         if (!sup_link) {
188                 dev_err(info->cpu_dev, "cpu%d: sup_link is NULL\n", info->opp_cpu);
189                 return false;
190         }
191
192         if (sup_link->supplier->links.status != DL_DEV_DRIVER_BOUND)
193                 return false;
194
195         info->ccifreq_bound = true;
196
197         return true;
198 }
199
200 static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
201                                   unsigned int index)
202 {
203         struct cpufreq_frequency_table *freq_table = policy->freq_table;
204         struct clk *cpu_clk = policy->clk;
205         struct clk *armpll = clk_get_parent(cpu_clk);
206         struct mtk_cpu_dvfs_info *info = policy->driver_data;
207         struct device *cpu_dev = info->cpu_dev;
208         struct dev_pm_opp *opp;
209         long freq_hz, pre_freq_hz;
210         int vproc, pre_vproc, inter_vproc, target_vproc, ret;
211
212         inter_vproc = info->intermediate_voltage;
213
214         pre_freq_hz = clk_get_rate(cpu_clk);
215
216         mutex_lock(&info->reg_lock);
217
218         if (unlikely(info->pre_vproc <= 0))
219                 pre_vproc = regulator_get_voltage(info->proc_reg);
220         else
221                 pre_vproc = info->pre_vproc;
222
223         if (pre_vproc < 0) {
224                 dev_err(cpu_dev, "invalid Vproc value: %d\n", pre_vproc);
225                 ret = pre_vproc;
226                 goto out;
227         }
228
229         freq_hz = freq_table[index].frequency * 1000;
230
231         opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
232         if (IS_ERR(opp)) {
233                 dev_err(cpu_dev, "cpu%d: failed to find OPP for %ld\n",
234                         policy->cpu, freq_hz);
235                 ret = PTR_ERR(opp);
236                 goto out;
237         }
238         vproc = dev_pm_opp_get_voltage(opp);
239         dev_pm_opp_put(opp);
240
241         /*
242          * If MediaTek cci is supported but is not ready, we will use the value
243          * of max(target cpu voltage, booting voltage) to prevent high freqeuncy
244          * low voltage crash.
245          */
246         if (info->soc_data->ccifreq_supported && !is_ccifreq_ready(info))
247                 vproc = max(vproc, info->vproc_on_boot);
248
249         /*
250          * If the new voltage or the intermediate voltage is higher than the
251          * current voltage, scale up voltage first.
252          */
253         target_vproc = max(inter_vproc, vproc);
254         if (pre_vproc <= target_vproc) {
255                 ret = mtk_cpufreq_set_voltage(info, target_vproc);
256                 if (ret) {
257                         dev_err(cpu_dev,
258                                 "cpu%d: failed to scale up voltage!\n", policy->cpu);
259                         mtk_cpufreq_set_voltage(info, pre_vproc);
260                         goto out;
261                 }
262         }
263
264         /* Reparent the CPU clock to intermediate clock. */
265         ret = clk_set_parent(cpu_clk, info->inter_clk);
266         if (ret) {
267                 dev_err(cpu_dev,
268                         "cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
269                 mtk_cpufreq_set_voltage(info, pre_vproc);
270                 goto out;
271         }
272
273         /* Set the original PLL to target rate. */
274         ret = clk_set_rate(armpll, freq_hz);
275         if (ret) {
276                 dev_err(cpu_dev,
277                         "cpu%d: failed to scale cpu clock rate!\n", policy->cpu);
278                 clk_set_parent(cpu_clk, armpll);
279                 mtk_cpufreq_set_voltage(info, pre_vproc);
280                 goto out;
281         }
282
283         /* Set parent of CPU clock back to the original PLL. */
284         ret = clk_set_parent(cpu_clk, armpll);
285         if (ret) {
286                 dev_err(cpu_dev,
287                         "cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
288                 mtk_cpufreq_set_voltage(info, inter_vproc);
289                 goto out;
290         }
291
292         /*
293          * If the new voltage is lower than the intermediate voltage or the
294          * original voltage, scale down to the new voltage.
295          */
296         if (vproc < inter_vproc || vproc < pre_vproc) {
297                 ret = mtk_cpufreq_set_voltage(info, vproc);
298                 if (ret) {
299                         dev_err(cpu_dev,
300                                 "cpu%d: failed to scale down voltage!\n", policy->cpu);
301                         clk_set_parent(cpu_clk, info->inter_clk);
302                         clk_set_rate(armpll, pre_freq_hz);
303                         clk_set_parent(cpu_clk, armpll);
304                         goto out;
305                 }
306         }
307
308         info->current_freq = freq_hz;
309
310 out:
311         mutex_unlock(&info->reg_lock);
312
313         return ret;
314 }
315
316 #define DYNAMIC_POWER "dynamic-power-coefficient"
317
318 static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
319                                     unsigned long event, void *data)
320 {
321         struct dev_pm_opp *opp = data;
322         struct dev_pm_opp *new_opp;
323         struct mtk_cpu_dvfs_info *info;
324         unsigned long freq, volt;
325         struct cpufreq_policy *policy;
326         int ret = 0;
327
328         info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
329
330         if (event == OPP_EVENT_ADJUST_VOLTAGE) {
331                 freq = dev_pm_opp_get_freq(opp);
332
333                 mutex_lock(&info->reg_lock);
334                 if (info->current_freq == freq) {
335                         volt = dev_pm_opp_get_voltage(opp);
336                         ret = mtk_cpufreq_set_voltage(info, volt);
337                         if (ret)
338                                 dev_err(info->cpu_dev,
339                                         "failed to scale voltage: %d\n", ret);
340                 }
341                 mutex_unlock(&info->reg_lock);
342         } else if (event == OPP_EVENT_DISABLE) {
343                 freq = dev_pm_opp_get_freq(opp);
344
345                 /* case of current opp item is disabled */
346                 if (info->current_freq == freq) {
347                         freq = 1;
348                         new_opp = dev_pm_opp_find_freq_ceil(info->cpu_dev,
349                                                             &freq);
350                         if (IS_ERR(new_opp)) {
351                                 dev_err(info->cpu_dev,
352                                         "all opp items are disabled\n");
353                                 ret = PTR_ERR(new_opp);
354                                 return notifier_from_errno(ret);
355                         }
356
357                         dev_pm_opp_put(new_opp);
358                         policy = cpufreq_cpu_get(info->opp_cpu);
359                         if (policy) {
360                                 cpufreq_driver_target(policy, freq / 1000,
361                                                       CPUFREQ_RELATION_L);
362                                 cpufreq_cpu_put(policy);
363                         }
364                 }
365         }
366
367         return notifier_from_errno(ret);
368 }
369
370 static struct device *of_get_cci(struct device *cpu_dev)
371 {
372         struct device_node *np;
373         struct platform_device *pdev;
374
375         np = of_parse_phandle(cpu_dev->of_node, "mediatek,cci", 0);
376         if (IS_ERR_OR_NULL(np))
377                 return NULL;
378
379         pdev = of_find_device_by_node(np);
380         of_node_put(np);
381         if (IS_ERR_OR_NULL(pdev))
382                 return NULL;
383
384         return &pdev->dev;
385 }
386
387 static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
388 {
389         struct device *cpu_dev;
390         struct dev_pm_opp *opp;
391         unsigned long rate;
392         int ret;
393
394         cpu_dev = get_cpu_device(cpu);
395         if (!cpu_dev) {
396                 dev_err(cpu_dev, "failed to get cpu%d device\n", cpu);
397                 return -ENODEV;
398         }
399         info->cpu_dev = cpu_dev;
400
401         info->ccifreq_bound = false;
402         if (info->soc_data->ccifreq_supported) {
403                 info->cci_dev = of_get_cci(info->cpu_dev);
404                 if (IS_ERR_OR_NULL(info->cci_dev)) {
405                         ret = PTR_ERR(info->cci_dev);
406                         dev_err(cpu_dev, "cpu%d: failed to get cci device\n", cpu);
407                         return -ENODEV;
408                 }
409         }
410
411         info->cpu_clk = clk_get(cpu_dev, "cpu");
412         if (IS_ERR(info->cpu_clk)) {
413                 ret = PTR_ERR(info->cpu_clk);
414                 return dev_err_probe(cpu_dev, ret,
415                                      "cpu%d: failed to get cpu clk\n", cpu);
416         }
417
418         info->inter_clk = clk_get(cpu_dev, "intermediate");
419         if (IS_ERR(info->inter_clk)) {
420                 ret = PTR_ERR(info->inter_clk);
421                 dev_err_probe(cpu_dev, ret,
422                               "cpu%d: failed to get intermediate clk\n", cpu);
423                 goto out_free_resources;
424         }
425
426         info->proc_reg = regulator_get_optional(cpu_dev, "proc");
427         if (IS_ERR(info->proc_reg)) {
428                 ret = PTR_ERR(info->proc_reg);
429                 dev_err_probe(cpu_dev, ret,
430                               "cpu%d: failed to get proc regulator\n", cpu);
431                 goto out_free_resources;
432         }
433
434         ret = regulator_enable(info->proc_reg);
435         if (ret) {
436                 dev_warn(cpu_dev, "cpu%d: failed to enable vproc\n", cpu);
437                 goto out_free_resources;
438         }
439
440         /* Both presence and absence of sram regulator are valid cases. */
441         info->sram_reg = regulator_get_optional(cpu_dev, "sram");
442         if (IS_ERR(info->sram_reg))
443                 info->sram_reg = NULL;
444         else {
445                 ret = regulator_enable(info->sram_reg);
446                 if (ret) {
447                         dev_warn(cpu_dev, "cpu%d: failed to enable vsram\n", cpu);
448                         goto out_free_resources;
449                 }
450         }
451
452         /* Get OPP-sharing information from "operating-points-v2" bindings */
453         ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, &info->cpus);
454         if (ret) {
455                 dev_err(cpu_dev,
456                         "cpu%d: failed to get OPP-sharing information\n", cpu);
457                 goto out_free_resources;
458         }
459
460         ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
461         if (ret) {
462                 dev_warn(cpu_dev, "cpu%d: no OPP table\n", cpu);
463                 goto out_free_resources;
464         }
465
466         ret = clk_prepare_enable(info->cpu_clk);
467         if (ret)
468                 goto out_free_opp_table;
469
470         ret = clk_prepare_enable(info->inter_clk);
471         if (ret)
472                 goto out_disable_mux_clock;
473
474         if (info->soc_data->ccifreq_supported) {
475                 info->vproc_on_boot = regulator_get_voltage(info->proc_reg);
476                 if (info->vproc_on_boot < 0) {
477                         dev_err(info->cpu_dev,
478                                 "invalid Vproc value: %d\n", info->vproc_on_boot);
479                         goto out_disable_inter_clock;
480                 }
481         }
482
483         /* Search a safe voltage for intermediate frequency. */
484         rate = clk_get_rate(info->inter_clk);
485         opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
486         if (IS_ERR(opp)) {
487                 dev_err(cpu_dev, "cpu%d: failed to get intermediate opp\n", cpu);
488                 ret = PTR_ERR(opp);
489                 goto out_disable_inter_clock;
490         }
491         info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
492         dev_pm_opp_put(opp);
493
494         mutex_init(&info->reg_lock);
495         info->current_freq = clk_get_rate(info->cpu_clk);
496
497         info->opp_cpu = cpu;
498         info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
499         ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
500         if (ret) {
501                 dev_err(cpu_dev, "cpu%d: failed to register opp notifier\n", cpu);
502                 goto out_disable_inter_clock;
503         }
504
505         /*
506          * If SRAM regulator is present, software "voltage tracking" is needed
507          * for this CPU power domain.
508          */
509         info->need_voltage_tracking = (info->sram_reg != NULL);
510
511         /*
512          * We assume min voltage is 0 and tracking target voltage using
513          * min_volt_shift for each iteration.
514          * The vtrack_max is 3 times of expeted iteration count.
515          */
516         info->vtrack_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
517                                                 info->soc_data->proc_max_volt),
518                                             info->soc_data->min_volt_shift);
519
520         return 0;
521
522 out_disable_inter_clock:
523         clk_disable_unprepare(info->inter_clk);
524
525 out_disable_mux_clock:
526         clk_disable_unprepare(info->cpu_clk);
527
528 out_free_opp_table:
529         dev_pm_opp_of_cpumask_remove_table(&info->cpus);
530
531 out_free_resources:
532         if (regulator_is_enabled(info->proc_reg))
533                 regulator_disable(info->proc_reg);
534         if (info->sram_reg && regulator_is_enabled(info->sram_reg))
535                 regulator_disable(info->sram_reg);
536
537         if (!IS_ERR(info->proc_reg))
538                 regulator_put(info->proc_reg);
539         if (!IS_ERR(info->sram_reg))
540                 regulator_put(info->sram_reg);
541         if (!IS_ERR(info->cpu_clk))
542                 clk_put(info->cpu_clk);
543         if (!IS_ERR(info->inter_clk))
544                 clk_put(info->inter_clk);
545
546         return ret;
547 }
548
549 static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
550 {
551         if (!IS_ERR(info->proc_reg)) {
552                 regulator_disable(info->proc_reg);
553                 regulator_put(info->proc_reg);
554         }
555         if (!IS_ERR(info->sram_reg)) {
556                 regulator_disable(info->sram_reg);
557                 regulator_put(info->sram_reg);
558         }
559         if (!IS_ERR(info->cpu_clk)) {
560                 clk_disable_unprepare(info->cpu_clk);
561                 clk_put(info->cpu_clk);
562         }
563         if (!IS_ERR(info->inter_clk)) {
564                 clk_disable_unprepare(info->inter_clk);
565                 clk_put(info->inter_clk);
566         }
567
568         dev_pm_opp_of_cpumask_remove_table(&info->cpus);
569         dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
570 }
571
572 static int mtk_cpufreq_init(struct cpufreq_policy *policy)
573 {
574         struct mtk_cpu_dvfs_info *info;
575         struct cpufreq_frequency_table *freq_table;
576         int ret;
577
578         info = mtk_cpu_dvfs_info_lookup(policy->cpu);
579         if (!info) {
580                 pr_err("dvfs info for cpu%d is not initialized.\n",
581                         policy->cpu);
582                 return -EINVAL;
583         }
584
585         ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
586         if (ret) {
587                 dev_err(info->cpu_dev,
588                         "failed to init cpufreq table for cpu%d: %d\n",
589                         policy->cpu, ret);
590                 return ret;
591         }
592
593         cpumask_copy(policy->cpus, &info->cpus);
594         policy->freq_table = freq_table;
595         policy->driver_data = info;
596         policy->clk = info->cpu_clk;
597
598         return 0;
599 }
600
601 static int mtk_cpufreq_exit(struct cpufreq_policy *policy)
602 {
603         struct mtk_cpu_dvfs_info *info = policy->driver_data;
604
605         dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
606
607         return 0;
608 }
609
610 static struct cpufreq_driver mtk_cpufreq_driver = {
611         .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
612                  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
613                  CPUFREQ_IS_COOLING_DEV,
614         .verify = cpufreq_generic_frequency_table_verify,
615         .target_index = mtk_cpufreq_set_target,
616         .get = cpufreq_generic_get,
617         .init = mtk_cpufreq_init,
618         .exit = mtk_cpufreq_exit,
619         .register_em = cpufreq_register_em_with_opp,
620         .name = "mtk-cpufreq",
621         .attr = cpufreq_generic_attr,
622 };
623
624 static int mtk_cpufreq_probe(struct platform_device *pdev)
625 {
626         const struct mtk_cpufreq_platform_data *data;
627         struct mtk_cpu_dvfs_info *info, *tmp;
628         int cpu, ret;
629
630         data = dev_get_platdata(&pdev->dev);
631         if (!data) {
632                 dev_err(&pdev->dev,
633                         "failed to get mtk cpufreq platform data\n");
634                 return -ENODEV;
635         }
636
637         for_each_possible_cpu(cpu) {
638                 info = mtk_cpu_dvfs_info_lookup(cpu);
639                 if (info)
640                         continue;
641
642                 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
643                 if (!info) {
644                         ret = -ENOMEM;
645                         goto release_dvfs_info_list;
646                 }
647
648                 info->soc_data = data;
649                 ret = mtk_cpu_dvfs_info_init(info, cpu);
650                 if (ret) {
651                         dev_err(&pdev->dev,
652                                 "failed to initialize dvfs info for cpu%d\n",
653                                 cpu);
654                         goto release_dvfs_info_list;
655                 }
656
657                 list_add(&info->list_head, &dvfs_info_list);
658         }
659
660         ret = cpufreq_register_driver(&mtk_cpufreq_driver);
661         if (ret) {
662                 dev_err(&pdev->dev, "failed to register mtk cpufreq driver\n");
663                 goto release_dvfs_info_list;
664         }
665
666         return 0;
667
668 release_dvfs_info_list:
669         list_for_each_entry_safe(info, tmp, &dvfs_info_list, list_head) {
670                 mtk_cpu_dvfs_info_release(info);
671                 list_del(&info->list_head);
672         }
673
674         return ret;
675 }
676
677 static struct platform_driver mtk_cpufreq_platdrv = {
678         .driver = {
679                 .name   = "mtk-cpufreq",
680         },
681         .probe          = mtk_cpufreq_probe,
682 };
683
684 static const struct mtk_cpufreq_platform_data mt2701_platform_data = {
685         .min_volt_shift = 100000,
686         .max_volt_shift = 200000,
687         .proc_max_volt = 1150000,
688         .sram_min_volt = 0,
689         .sram_max_volt = 1150000,
690         .ccifreq_supported = false,
691 };
692
693 static const struct mtk_cpufreq_platform_data mt8183_platform_data = {
694         .min_volt_shift = 100000,
695         .max_volt_shift = 200000,
696         .proc_max_volt = 1150000,
697         .sram_min_volt = 0,
698         .sram_max_volt = 1150000,
699         .ccifreq_supported = true,
700 };
701
702 static const struct mtk_cpufreq_platform_data mt8186_platform_data = {
703         .min_volt_shift = 100000,
704         .max_volt_shift = 250000,
705         .proc_max_volt = 1118750,
706         .sram_min_volt = 850000,
707         .sram_max_volt = 1118750,
708         .ccifreq_supported = true,
709 };
710
711 /* List of machines supported by this driver */
712 static const struct of_device_id mtk_cpufreq_machines[] __initconst = {
713         { .compatible = "mediatek,mt2701", .data = &mt2701_platform_data },
714         { .compatible = "mediatek,mt2712", .data = &mt2701_platform_data },
715         { .compatible = "mediatek,mt7622", .data = &mt2701_platform_data },
716         { .compatible = "mediatek,mt7623", .data = &mt2701_platform_data },
717         { .compatible = "mediatek,mt8167", .data = &mt2701_platform_data },
718         { .compatible = "mediatek,mt817x", .data = &mt2701_platform_data },
719         { .compatible = "mediatek,mt8173", .data = &mt2701_platform_data },
720         { .compatible = "mediatek,mt8176", .data = &mt2701_platform_data },
721         { .compatible = "mediatek,mt8183", .data = &mt8183_platform_data },
722         { .compatible = "mediatek,mt8186", .data = &mt8186_platform_data },
723         { .compatible = "mediatek,mt8365", .data = &mt2701_platform_data },
724         { .compatible = "mediatek,mt8516", .data = &mt2701_platform_data },
725         { }
726 };
727 MODULE_DEVICE_TABLE(of, mtk_cpufreq_machines);
728
729 static int __init mtk_cpufreq_driver_init(void)
730 {
731         struct device_node *np;
732         const struct of_device_id *match;
733         const struct mtk_cpufreq_platform_data *data;
734         int err;
735
736         np = of_find_node_by_path("/");
737         if (!np)
738                 return -ENODEV;
739
740         match = of_match_node(mtk_cpufreq_machines, np);
741         of_node_put(np);
742         if (!match) {
743                 pr_debug("Machine is not compatible with mtk-cpufreq\n");
744                 return -ENODEV;
745         }
746         data = match->data;
747
748         err = platform_driver_register(&mtk_cpufreq_platdrv);
749         if (err)
750                 return err;
751
752         /*
753          * Since there's no place to hold device registration code and no
754          * device tree based way to match cpufreq driver yet, both the driver
755          * and the device registration codes are put here to handle defer
756          * probing.
757          */
758         cpufreq_pdev = platform_device_register_data(NULL, "mtk-cpufreq", -1,
759                                                      data, sizeof(*data));
760         if (IS_ERR(cpufreq_pdev)) {
761                 pr_err("failed to register mtk-cpufreq platform device\n");
762                 platform_driver_unregister(&mtk_cpufreq_platdrv);
763                 return PTR_ERR(cpufreq_pdev);
764         }
765
766         return 0;
767 }
768 module_init(mtk_cpufreq_driver_init)
769
770 static void __exit mtk_cpufreq_driver_exit(void)
771 {
772         platform_device_unregister(cpufreq_pdev);
773         platform_driver_unregister(&mtk_cpufreq_platdrv);
774 }
775 module_exit(mtk_cpufreq_driver_exit)
776
777 MODULE_DESCRIPTION("MediaTek CPUFreq driver");
778 MODULE_AUTHOR("Pi-Cheng Chen <pi-cheng.chen@linaro.org>");
779 MODULE_LICENSE("GPL v2");