xref: /linux/drivers/cpufreq/mediatek-cpufreq.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
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 static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
317 				    unsigned long event, void *data)
318 {
319 	struct dev_pm_opp *opp = data;
320 	struct dev_pm_opp *new_opp;
321 	struct mtk_cpu_dvfs_info *info;
322 	unsigned long freq, volt;
323 	struct cpufreq_policy *policy;
324 	int ret = 0;
325 
326 	info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
327 
328 	if (event == OPP_EVENT_ADJUST_VOLTAGE) {
329 		freq = dev_pm_opp_get_freq(opp);
330 
331 		mutex_lock(&info->reg_lock);
332 		if (info->current_freq == freq) {
333 			volt = dev_pm_opp_get_voltage(opp);
334 			ret = mtk_cpufreq_set_voltage(info, volt);
335 			if (ret)
336 				dev_err(info->cpu_dev,
337 					"failed to scale voltage: %d\n", ret);
338 		}
339 		mutex_unlock(&info->reg_lock);
340 	} else if (event == OPP_EVENT_DISABLE) {
341 		freq = dev_pm_opp_get_freq(opp);
342 
343 		/* case of current opp item is disabled */
344 		if (info->current_freq == freq) {
345 			freq = 1;
346 			new_opp = dev_pm_opp_find_freq_ceil(info->cpu_dev,
347 							    &freq);
348 			if (IS_ERR(new_opp)) {
349 				dev_err(info->cpu_dev,
350 					"all opp items are disabled\n");
351 				ret = PTR_ERR(new_opp);
352 				return notifier_from_errno(ret);
353 			}
354 
355 			dev_pm_opp_put(new_opp);
356 			policy = cpufreq_cpu_get(info->opp_cpu);
357 			if (policy) {
358 				cpufreq_driver_target(policy, freq / 1000,
359 						      CPUFREQ_RELATION_L);
360 				cpufreq_cpu_put(policy);
361 			}
362 		}
363 	}
364 
365 	return notifier_from_errno(ret);
366 }
367 
368 static struct device *of_get_cci(struct device *cpu_dev)
369 {
370 	struct device_node *np;
371 	struct platform_device *pdev;
372 
373 	np = of_parse_phandle(cpu_dev->of_node, "mediatek,cci", 0);
374 	if (!np)
375 		return ERR_PTR(-ENODEV);
376 
377 	pdev = of_find_device_by_node(np);
378 	of_node_put(np);
379 	if (!pdev)
380 		return ERR_PTR(-ENODEV);
381 
382 	return &pdev->dev;
383 }
384 
385 static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
386 {
387 	struct device *cpu_dev;
388 	struct dev_pm_opp *opp;
389 	unsigned long rate;
390 	int ret;
391 
392 	cpu_dev = get_cpu_device(cpu);
393 	if (!cpu_dev)
394 		return dev_err_probe(cpu_dev, -ENODEV, "failed to get cpu%d device\n", cpu);
395 	info->cpu_dev = cpu_dev;
396 
397 	info->ccifreq_bound = false;
398 	if (info->soc_data->ccifreq_supported) {
399 		info->cci_dev = of_get_cci(info->cpu_dev);
400 		if (IS_ERR(info->cci_dev))
401 			return dev_err_probe(cpu_dev, PTR_ERR(info->cci_dev),
402 					     "cpu%d: failed to get cci device\n",
403 					     cpu);
404 	}
405 
406 	info->cpu_clk = clk_get(cpu_dev, "cpu");
407 	if (IS_ERR(info->cpu_clk))
408 		return dev_err_probe(cpu_dev, PTR_ERR(info->cpu_clk),
409 				     "cpu%d: failed to get cpu clk\n", cpu);
410 
411 	info->inter_clk = clk_get(cpu_dev, "intermediate");
412 	if (IS_ERR(info->inter_clk)) {
413 		ret = PTR_ERR(info->inter_clk);
414 		dev_err_probe(cpu_dev, ret,
415 			      "cpu%d: failed to get intermediate clk\n", cpu);
416 		goto out_free_mux_clock;
417 	}
418 
419 	info->proc_reg = regulator_get_optional(cpu_dev, "proc");
420 	if (IS_ERR(info->proc_reg)) {
421 		ret = PTR_ERR(info->proc_reg);
422 		dev_err_probe(cpu_dev, ret,
423 			      "cpu%d: failed to get proc regulator\n", cpu);
424 		goto out_free_inter_clock;
425 	}
426 
427 	ret = regulator_enable(info->proc_reg);
428 	if (ret) {
429 		dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable vproc\n", cpu);
430 		goto out_free_proc_reg;
431 	}
432 
433 	/* Both presence and absence of sram regulator are valid cases. */
434 	info->sram_reg = regulator_get_optional(cpu_dev, "sram");
435 	if (IS_ERR(info->sram_reg)) {
436 		ret = PTR_ERR(info->sram_reg);
437 		if (ret == -EPROBE_DEFER) {
438 			dev_err_probe(cpu_dev, ret,
439 				      "cpu%d: Failed to get sram regulator\n", cpu);
440 			goto out_disable_proc_reg;
441 		}
442 
443 		info->sram_reg = NULL;
444 	} else {
445 		ret = regulator_enable(info->sram_reg);
446 		if (ret) {
447 			dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable vsram\n", cpu);
448 			goto out_free_sram_reg;
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_probe(cpu_dev, ret,
456 			"cpu%d: failed to get OPP-sharing information\n", cpu);
457 		goto out_disable_sram_reg;
458 	}
459 
460 	ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
461 	if (ret) {
462 		dev_err_probe(cpu_dev, ret, "cpu%d: no OPP table\n", cpu);
463 		goto out_disable_sram_reg;
464 	}
465 
466 	ret = clk_prepare_enable(info->cpu_clk);
467 	if (ret) {
468 		dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable cpu clk\n", cpu);
469 		goto out_free_opp_table;
470 	}
471 
472 	ret = clk_prepare_enable(info->inter_clk);
473 	if (ret) {
474 		dev_err_probe(cpu_dev, ret, "cpu%d: failed to enable inter clk\n", cpu);
475 		goto out_disable_mux_clock;
476 	}
477 
478 	if (info->soc_data->ccifreq_supported) {
479 		info->vproc_on_boot = regulator_get_voltage(info->proc_reg);
480 		if (info->vproc_on_boot < 0) {
481 			ret = dev_err_probe(info->cpu_dev, info->vproc_on_boot,
482 					    "invalid Vproc value\n");
483 			goto out_disable_inter_clock;
484 		}
485 	}
486 
487 	/* Search a safe voltage for intermediate frequency. */
488 	rate = clk_get_rate(info->inter_clk);
489 	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
490 	if (IS_ERR(opp)) {
491 		ret = dev_err_probe(cpu_dev, PTR_ERR(opp),
492 				    "cpu%d: failed to get intermediate opp\n", cpu);
493 		goto out_disable_inter_clock;
494 	}
495 	info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
496 	dev_pm_opp_put(opp);
497 
498 	mutex_init(&info->reg_lock);
499 	info->current_freq = clk_get_rate(info->cpu_clk);
500 
501 	info->opp_cpu = cpu;
502 	info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
503 	ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
504 	if (ret) {
505 		dev_err_probe(cpu_dev, ret, "cpu%d: failed to register opp notifier\n", cpu);
506 		goto out_disable_inter_clock;
507 	}
508 
509 	/*
510 	 * If SRAM regulator is present, software "voltage tracking" is needed
511 	 * for this CPU power domain.
512 	 */
513 	info->need_voltage_tracking = (info->sram_reg != NULL);
514 
515 	/*
516 	 * We assume min voltage is 0 and tracking target voltage using
517 	 * min_volt_shift for each iteration.
518 	 * The vtrack_max is 3 times of expeted iteration count.
519 	 */
520 	info->vtrack_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
521 						info->soc_data->proc_max_volt),
522 					    info->soc_data->min_volt_shift);
523 
524 	return 0;
525 
526 out_disable_inter_clock:
527 	clk_disable_unprepare(info->inter_clk);
528 
529 out_disable_mux_clock:
530 	clk_disable_unprepare(info->cpu_clk);
531 
532 out_free_opp_table:
533 	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
534 
535 out_disable_sram_reg:
536 	if (info->sram_reg)
537 		regulator_disable(info->sram_reg);
538 
539 out_free_sram_reg:
540 	if (info->sram_reg)
541 		regulator_put(info->sram_reg);
542 
543 out_disable_proc_reg:
544 	regulator_disable(info->proc_reg);
545 
546 out_free_proc_reg:
547 	regulator_put(info->proc_reg);
548 
549 out_free_inter_clock:
550 	clk_put(info->inter_clk);
551 
552 out_free_mux_clock:
553 	clk_put(info->cpu_clk);
554 
555 	return ret;
556 }
557 
558 static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
559 {
560 	regulator_disable(info->proc_reg);
561 	regulator_put(info->proc_reg);
562 	if (info->sram_reg) {
563 		regulator_disable(info->sram_reg);
564 		regulator_put(info->sram_reg);
565 	}
566 	clk_disable_unprepare(info->cpu_clk);
567 	clk_put(info->cpu_clk);
568 	clk_disable_unprepare(info->inter_clk);
569 	clk_put(info->inter_clk);
570 	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
571 	dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
572 }
573 
574 static int mtk_cpufreq_init(struct cpufreq_policy *policy)
575 {
576 	struct mtk_cpu_dvfs_info *info;
577 	struct cpufreq_frequency_table *freq_table;
578 	int ret;
579 
580 	info = mtk_cpu_dvfs_info_lookup(policy->cpu);
581 	if (!info) {
582 		pr_err("dvfs info for cpu%d is not initialized.\n",
583 			policy->cpu);
584 		return -EINVAL;
585 	}
586 
587 	ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
588 	if (ret) {
589 		dev_err(info->cpu_dev,
590 			"failed to init cpufreq table for cpu%d: %d\n",
591 			policy->cpu, ret);
592 		return ret;
593 	}
594 
595 	cpumask_copy(policy->cpus, &info->cpus);
596 	policy->freq_table = freq_table;
597 	policy->driver_data = info;
598 	policy->clk = info->cpu_clk;
599 
600 	return 0;
601 }
602 
603 static void mtk_cpufreq_exit(struct cpufreq_policy *policy)
604 {
605 	struct mtk_cpu_dvfs_info *info = policy->driver_data;
606 
607 	dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
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 		return dev_err_probe(&pdev->dev, -ENODEV,
633 				     "failed to get mtk cpufreq platform data\n");
634 
635 	for_each_possible_cpu(cpu) {
636 		info = mtk_cpu_dvfs_info_lookup(cpu);
637 		if (info)
638 			continue;
639 
640 		info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
641 		if (!info) {
642 			ret = dev_err_probe(&pdev->dev, -ENOMEM,
643 					    "Failed to allocate dvfs_info\n");
644 			goto release_dvfs_info_list;
645 		}
646 
647 		info->soc_data = data;
648 		ret = mtk_cpu_dvfs_info_init(info, cpu);
649 		if (ret)
650 			goto release_dvfs_info_list;
651 
652 		list_add(&info->list_head, &dvfs_info_list);
653 	}
654 
655 	ret = cpufreq_register_driver(&mtk_cpufreq_driver);
656 	if (ret) {
657 		dev_err_probe(&pdev->dev, ret, "failed to register mtk cpufreq driver\n");
658 		goto release_dvfs_info_list;
659 	}
660 
661 	return 0;
662 
663 release_dvfs_info_list:
664 	list_for_each_entry_safe(info, tmp, &dvfs_info_list, list_head) {
665 		mtk_cpu_dvfs_info_release(info);
666 		list_del(&info->list_head);
667 	}
668 
669 	return ret;
670 }
671 
672 static struct platform_driver mtk_cpufreq_platdrv = {
673 	.driver = {
674 		.name	= "mtk-cpufreq",
675 	},
676 	.probe		= mtk_cpufreq_probe,
677 };
678 
679 static const struct mtk_cpufreq_platform_data mt2701_platform_data = {
680 	.min_volt_shift = 100000,
681 	.max_volt_shift = 200000,
682 	.proc_max_volt = 1150000,
683 	.sram_min_volt = 0,
684 	.sram_max_volt = 1150000,
685 	.ccifreq_supported = false,
686 };
687 
688 static const struct mtk_cpufreq_platform_data mt7622_platform_data = {
689 	.min_volt_shift = 100000,
690 	.max_volt_shift = 200000,
691 	.proc_max_volt = 1350000,
692 	.sram_min_volt = 0,
693 	.sram_max_volt = 1350000,
694 	.ccifreq_supported = false,
695 };
696 
697 static const struct mtk_cpufreq_platform_data mt7623_platform_data = {
698 	.min_volt_shift = 100000,
699 	.max_volt_shift = 200000,
700 	.proc_max_volt = 1300000,
701 	.ccifreq_supported = false,
702 };
703 
704 static const struct mtk_cpufreq_platform_data mt7988_platform_data = {
705 	.min_volt_shift = 100000,
706 	.max_volt_shift = 200000,
707 	.proc_max_volt = 900000,
708 	.sram_min_volt = 0,
709 	.sram_max_volt = 1150000,
710 	.ccifreq_supported = true,
711 };
712 
713 static const struct mtk_cpufreq_platform_data mt8183_platform_data = {
714 	.min_volt_shift = 100000,
715 	.max_volt_shift = 200000,
716 	.proc_max_volt = 1150000,
717 	.sram_min_volt = 0,
718 	.sram_max_volt = 1150000,
719 	.ccifreq_supported = true,
720 };
721 
722 static const struct mtk_cpufreq_platform_data mt8186_platform_data = {
723 	.min_volt_shift = 100000,
724 	.max_volt_shift = 250000,
725 	.proc_max_volt = 1118750,
726 	.sram_min_volt = 850000,
727 	.sram_max_volt = 1118750,
728 	.ccifreq_supported = true,
729 };
730 
731 static const struct mtk_cpufreq_platform_data mt8516_platform_data = {
732 	.min_volt_shift = 100000,
733 	.max_volt_shift = 200000,
734 	.proc_max_volt = 1310000,
735 	.sram_min_volt = 0,
736 	.sram_max_volt = 1310000,
737 	.ccifreq_supported = false,
738 };
739 
740 /* List of machines supported by this driver */
741 static const struct of_device_id mtk_cpufreq_machines[] __initconst = {
742 	{ .compatible = "mediatek,mt2701", .data = &mt2701_platform_data },
743 	{ .compatible = "mediatek,mt2712", .data = &mt2701_platform_data },
744 	{ .compatible = "mediatek,mt7622", .data = &mt7622_platform_data },
745 	{ .compatible = "mediatek,mt7623", .data = &mt7623_platform_data },
746 	{ .compatible = "mediatek,mt7988a", .data = &mt7988_platform_data },
747 	{ .compatible = "mediatek,mt8167", .data = &mt8516_platform_data },
748 	{ .compatible = "mediatek,mt817x", .data = &mt2701_platform_data },
749 	{ .compatible = "mediatek,mt8173", .data = &mt2701_platform_data },
750 	{ .compatible = "mediatek,mt8176", .data = &mt2701_platform_data },
751 	{ .compatible = "mediatek,mt8183", .data = &mt8183_platform_data },
752 	{ .compatible = "mediatek,mt8186", .data = &mt8186_platform_data },
753 	{ .compatible = "mediatek,mt8365", .data = &mt2701_platform_data },
754 	{ .compatible = "mediatek,mt8516", .data = &mt8516_platform_data },
755 	{ }
756 };
757 MODULE_DEVICE_TABLE(of, mtk_cpufreq_machines);
758 
759 static int __init mtk_cpufreq_driver_init(void)
760 {
761 	struct device_node *np;
762 	const struct of_device_id *match;
763 	const struct mtk_cpufreq_platform_data *data;
764 	int err;
765 
766 	np = of_find_node_by_path("/");
767 	if (!np)
768 		return -ENODEV;
769 
770 	match = of_match_node(mtk_cpufreq_machines, np);
771 	of_node_put(np);
772 	if (!match) {
773 		pr_debug("Machine is not compatible with mtk-cpufreq\n");
774 		return -ENODEV;
775 	}
776 	data = match->data;
777 
778 	err = platform_driver_register(&mtk_cpufreq_platdrv);
779 	if (err)
780 		return err;
781 
782 	/*
783 	 * Since there's no place to hold device registration code and no
784 	 * device tree based way to match cpufreq driver yet, both the driver
785 	 * and the device registration codes are put here to handle defer
786 	 * probing.
787 	 */
788 	cpufreq_pdev = platform_device_register_data(NULL, "mtk-cpufreq", -1,
789 						     data, sizeof(*data));
790 	if (IS_ERR(cpufreq_pdev)) {
791 		pr_err("failed to register mtk-cpufreq platform device\n");
792 		platform_driver_unregister(&mtk_cpufreq_platdrv);
793 		return PTR_ERR(cpufreq_pdev);
794 	}
795 
796 	return 0;
797 }
798 module_init(mtk_cpufreq_driver_init)
799 
800 static void __exit mtk_cpufreq_driver_exit(void)
801 {
802 	platform_device_unregister(cpufreq_pdev);
803 	platform_driver_unregister(&mtk_cpufreq_platdrv);
804 }
805 module_exit(mtk_cpufreq_driver_exit)
806 
807 MODULE_DESCRIPTION("MediaTek CPUFreq driver");
808 MODULE_AUTHOR("Pi-Cheng Chen <pi-cheng.chen@linaro.org>");
809 MODULE_LICENSE("GPL v2");
810