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v6.8
  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
 19struct 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 */
 39struct 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
 62static struct platform_device *cpufreq_pdev;
 63
 64static LIST_HEAD(dvfs_info_list);
 65
 66static 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
 78static 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
162static 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
178static 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
200static 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
310out:
311	mutex_unlock(&info->reg_lock);
312
313	return ret;
314}
315
316static 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
368static 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
385static 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		dev_err(cpu_dev, "failed to get cpu%d device\n", cpu);
395		return -ENODEV;
396	}
397	info->cpu_dev = cpu_dev;
398
399	info->ccifreq_bound = false;
400	if (info->soc_data->ccifreq_supported) {
401		info->cci_dev = of_get_cci(info->cpu_dev);
402		if (IS_ERR(info->cci_dev)) {
403			ret = PTR_ERR(info->cci_dev);
404			dev_err(cpu_dev, "cpu%d: failed to get cci device\n", cpu);
405			return -ENODEV;
406		}
 
407	}
408
409	info->cpu_clk = clk_get(cpu_dev, "cpu");
410	if (IS_ERR(info->cpu_clk)) {
411		ret = PTR_ERR(info->cpu_clk);
412		return dev_err_probe(cpu_dev, ret,
413				     "cpu%d: failed to get cpu clk\n", cpu);
414	}
415
416	info->inter_clk = clk_get(cpu_dev, "intermediate");
417	if (IS_ERR(info->inter_clk)) {
418		ret = PTR_ERR(info->inter_clk);
419		dev_err_probe(cpu_dev, ret,
420			      "cpu%d: failed to get intermediate clk\n", cpu);
421		goto out_free_mux_clock;
422	}
423
424	info->proc_reg = regulator_get_optional(cpu_dev, "proc");
425	if (IS_ERR(info->proc_reg)) {
426		ret = PTR_ERR(info->proc_reg);
427		dev_err_probe(cpu_dev, ret,
428			      "cpu%d: failed to get proc regulator\n", cpu);
429		goto out_free_inter_clock;
430	}
431
432	ret = regulator_enable(info->proc_reg);
433	if (ret) {
434		dev_warn(cpu_dev, "cpu%d: failed to enable vproc\n", cpu);
435		goto out_free_proc_reg;
 
 
 
 
 
 
 
436	}
437
438	/* Both presence and absence of sram regulator are valid cases. */
439	info->sram_reg = regulator_get_optional(cpu_dev, "sram");
440	if (IS_ERR(info->sram_reg)) {
441		ret = PTR_ERR(info->sram_reg);
442		if (ret == -EPROBE_DEFER)
443			goto out_disable_proc_reg;
444
445		info->sram_reg = NULL;
446	} else {
447		ret = regulator_enable(info->sram_reg);
448		if (ret) {
449			dev_warn(cpu_dev, "cpu%d: failed to enable vsram\n", cpu);
450			goto out_free_sram_reg;
451		}
452	}
453
454	/* Get OPP-sharing information from "operating-points-v2" bindings */
455	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, &info->cpus);
456	if (ret) {
457		dev_err(cpu_dev,
458			"cpu%d: failed to get OPP-sharing information\n", cpu);
459		goto out_disable_sram_reg;
460	}
461
462	ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
463	if (ret) {
464		dev_warn(cpu_dev, "cpu%d: no OPP table\n", cpu);
465		goto out_disable_sram_reg;
466	}
467
468	ret = clk_prepare_enable(info->cpu_clk);
469	if (ret)
470		goto out_free_opp_table;
471
472	ret = clk_prepare_enable(info->inter_clk);
473	if (ret)
474		goto out_disable_mux_clock;
475
476	if (info->soc_data->ccifreq_supported) {
477		info->vproc_on_boot = regulator_get_voltage(info->proc_reg);
478		if (info->vproc_on_boot < 0) {
479			ret = info->vproc_on_boot;
480			dev_err(info->cpu_dev,
481				"invalid Vproc value: %d\n", info->vproc_on_boot);
482			goto out_disable_inter_clock;
483		}
484	}
485
486	/* Search a safe voltage for intermediate frequency. */
487	rate = clk_get_rate(info->inter_clk);
488	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
489	if (IS_ERR(opp)) {
490		dev_err(cpu_dev, "cpu%d: failed to get intermediate opp\n", cpu);
491		ret = PTR_ERR(opp);
492		goto out_disable_inter_clock;
493	}
494	info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
495	dev_pm_opp_put(opp);
496
497	mutex_init(&info->reg_lock);
498	info->current_freq = clk_get_rate(info->cpu_clk);
499
500	info->opp_cpu = cpu;
501	info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
502	ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
503	if (ret) {
504		dev_err(cpu_dev, "cpu%d: failed to register opp notifier\n", cpu);
505		goto out_disable_inter_clock;
506	}
507
508	/*
509	 * If SRAM regulator is present, software "voltage tracking" is needed
510	 * for this CPU power domain.
511	 */
512	info->need_voltage_tracking = (info->sram_reg != NULL);
513
514	/*
515	 * We assume min voltage is 0 and tracking target voltage using
516	 * min_volt_shift for each iteration.
517	 * The vtrack_max is 3 times of expeted iteration count.
518	 */
519	info->vtrack_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
520						info->soc_data->proc_max_volt),
521					    info->soc_data->min_volt_shift);
522
523	return 0;
524
525out_disable_inter_clock:
526	clk_disable_unprepare(info->inter_clk);
527
528out_disable_mux_clock:
529	clk_disable_unprepare(info->cpu_clk);
530
531out_free_opp_table:
532	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
533
534out_disable_sram_reg:
535	if (info->sram_reg)
536		regulator_disable(info->sram_reg);
537
538out_free_sram_reg:
539	if (info->sram_reg)
540		regulator_put(info->sram_reg);
541
542out_disable_proc_reg:
543	regulator_disable(info->proc_reg);
544
545out_free_proc_reg:
546	regulator_put(info->proc_reg);
547
548out_free_inter_clock:
549	clk_put(info->inter_clk);
550
551out_free_mux_clock:
552	clk_put(info->cpu_clk);
553
554	return ret;
555}
556
557static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
558{
559	regulator_disable(info->proc_reg);
560	regulator_put(info->proc_reg);
561	if (info->sram_reg) {
562		regulator_disable(info->sram_reg);
563		regulator_put(info->sram_reg);
564	}
565	clk_disable_unprepare(info->cpu_clk);
566	clk_put(info->cpu_clk);
567	clk_disable_unprepare(info->inter_clk);
568	clk_put(info->inter_clk);
569	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
570	dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
571}
572
573static int mtk_cpufreq_init(struct cpufreq_policy *policy)
574{
575	struct mtk_cpu_dvfs_info *info;
576	struct cpufreq_frequency_table *freq_table;
577	int ret;
578
579	info = mtk_cpu_dvfs_info_lookup(policy->cpu);
580	if (!info) {
581		pr_err("dvfs info for cpu%d is not initialized.\n",
582			policy->cpu);
583		return -EINVAL;
584	}
585
586	ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
587	if (ret) {
588		dev_err(info->cpu_dev,
589			"failed to init cpufreq table for cpu%d: %d\n",
590			policy->cpu, ret);
591		return ret;
592	}
593
594	cpumask_copy(policy->cpus, &info->cpus);
595	policy->freq_table = freq_table;
596	policy->driver_data = info;
597	policy->clk = info->cpu_clk;
598
 
 
599	return 0;
600}
601
602static int mtk_cpufreq_exit(struct cpufreq_policy *policy)
603{
604	struct mtk_cpu_dvfs_info *info = policy->driver_data;
605
606	dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
607
608	return 0;
609}
610
611static struct cpufreq_driver mtk_cpufreq_driver = {
612	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
613		 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
614		 CPUFREQ_IS_COOLING_DEV,
615	.verify = cpufreq_generic_frequency_table_verify,
616	.target_index = mtk_cpufreq_set_target,
617	.get = cpufreq_generic_get,
618	.init = mtk_cpufreq_init,
619	.exit = mtk_cpufreq_exit,
620	.register_em = cpufreq_register_em_with_opp,
621	.name = "mtk-cpufreq",
622	.attr = cpufreq_generic_attr,
623};
624
625static int mtk_cpufreq_probe(struct platform_device *pdev)
626{
627	const struct mtk_cpufreq_platform_data *data;
628	struct mtk_cpu_dvfs_info *info, *tmp;
629	int cpu, ret;
630
631	data = dev_get_platdata(&pdev->dev);
632	if (!data) {
633		dev_err(&pdev->dev,
634			"failed to get mtk cpufreq platform data\n");
635		return -ENODEV;
636	}
637
638	for_each_possible_cpu(cpu) {
639		info = mtk_cpu_dvfs_info_lookup(cpu);
640		if (info)
641			continue;
642
643		info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
644		if (!info) {
645			ret = -ENOMEM;
646			goto release_dvfs_info_list;
647		}
648
649		info->soc_data = data;
650		ret = mtk_cpu_dvfs_info_init(info, cpu);
651		if (ret) {
652			dev_err(&pdev->dev,
653				"failed to initialize dvfs info for cpu%d\n",
654				cpu);
655			goto release_dvfs_info_list;
656		}
657
658		list_add(&info->list_head, &dvfs_info_list);
659	}
660
661	ret = cpufreq_register_driver(&mtk_cpufreq_driver);
662	if (ret) {
663		dev_err(&pdev->dev, "failed to register mtk cpufreq driver\n");
664		goto release_dvfs_info_list;
665	}
666
667	return 0;
668
669release_dvfs_info_list:
670	list_for_each_entry_safe(info, tmp, &dvfs_info_list, list_head) {
671		mtk_cpu_dvfs_info_release(info);
672		list_del(&info->list_head);
673	}
674
675	return ret;
676}
677
678static struct platform_driver mtk_cpufreq_platdrv = {
679	.driver = {
680		.name	= "mtk-cpufreq",
681	},
682	.probe		= mtk_cpufreq_probe,
683};
684
685static const struct mtk_cpufreq_platform_data mt2701_platform_data = {
686	.min_volt_shift = 100000,
687	.max_volt_shift = 200000,
688	.proc_max_volt = 1150000,
689	.sram_min_volt = 0,
690	.sram_max_volt = 1150000,
691	.ccifreq_supported = false,
692};
693
694static const struct mtk_cpufreq_platform_data mt7622_platform_data = {
695	.min_volt_shift = 100000,
696	.max_volt_shift = 200000,
697	.proc_max_volt = 1350000,
698	.sram_min_volt = 0,
699	.sram_max_volt = 1350000,
700	.ccifreq_supported = false,
701};
702
703static const struct mtk_cpufreq_platform_data mt7623_platform_data = {
704	.min_volt_shift = 100000,
705	.max_volt_shift = 200000,
706	.proc_max_volt = 1300000,
707	.ccifreq_supported = false,
708};
709
710static const struct mtk_cpufreq_platform_data mt8183_platform_data = {
711	.min_volt_shift = 100000,
712	.max_volt_shift = 200000,
713	.proc_max_volt = 1150000,
714	.sram_min_volt = 0,
715	.sram_max_volt = 1150000,
716	.ccifreq_supported = true,
717};
718
719static const struct mtk_cpufreq_platform_data mt8186_platform_data = {
720	.min_volt_shift = 100000,
721	.max_volt_shift = 250000,
722	.proc_max_volt = 1118750,
723	.sram_min_volt = 850000,
724	.sram_max_volt = 1118750,
725	.ccifreq_supported = true,
726};
727
728static const struct mtk_cpufreq_platform_data mt8516_platform_data = {
729	.min_volt_shift = 100000,
730	.max_volt_shift = 200000,
731	.proc_max_volt = 1310000,
732	.sram_min_volt = 0,
733	.sram_max_volt = 1310000,
734	.ccifreq_supported = false,
735};
736
737/* List of machines supported by this driver */
738static const struct of_device_id mtk_cpufreq_machines[] __initconst = {
739	{ .compatible = "mediatek,mt2701", .data = &mt2701_platform_data },
740	{ .compatible = "mediatek,mt2712", .data = &mt2701_platform_data },
741	{ .compatible = "mediatek,mt7622", .data = &mt7622_platform_data },
742	{ .compatible = "mediatek,mt7623", .data = &mt7623_platform_data },
743	{ .compatible = "mediatek,mt8167", .data = &mt8516_platform_data },
744	{ .compatible = "mediatek,mt817x", .data = &mt2701_platform_data },
745	{ .compatible = "mediatek,mt8173", .data = &mt2701_platform_data },
746	{ .compatible = "mediatek,mt8176", .data = &mt2701_platform_data },
747	{ .compatible = "mediatek,mt8183", .data = &mt8183_platform_data },
748	{ .compatible = "mediatek,mt8186", .data = &mt8186_platform_data },
749	{ .compatible = "mediatek,mt8365", .data = &mt2701_platform_data },
750	{ .compatible = "mediatek,mt8516", .data = &mt8516_platform_data },
751	{ }
752};
753MODULE_DEVICE_TABLE(of, mtk_cpufreq_machines);
754
755static int __init mtk_cpufreq_driver_init(void)
756{
757	struct device_node *np;
758	const struct of_device_id *match;
759	const struct mtk_cpufreq_platform_data *data;
760	int err;
761
762	np = of_find_node_by_path("/");
763	if (!np)
764		return -ENODEV;
765
766	match = of_match_node(mtk_cpufreq_machines, np);
767	of_node_put(np);
768	if (!match) {
769		pr_debug("Machine is not compatible with mtk-cpufreq\n");
770		return -ENODEV;
771	}
772	data = match->data;
773
774	err = platform_driver_register(&mtk_cpufreq_platdrv);
775	if (err)
776		return err;
777
778	/*
779	 * Since there's no place to hold device registration code and no
780	 * device tree based way to match cpufreq driver yet, both the driver
781	 * and the device registration codes are put here to handle defer
782	 * probing.
783	 */
784	cpufreq_pdev = platform_device_register_data(NULL, "mtk-cpufreq", -1,
785						     data, sizeof(*data));
786	if (IS_ERR(cpufreq_pdev)) {
787		pr_err("failed to register mtk-cpufreq platform device\n");
788		platform_driver_unregister(&mtk_cpufreq_platdrv);
789		return PTR_ERR(cpufreq_pdev);
790	}
791
792	return 0;
793}
794module_init(mtk_cpufreq_driver_init)
795
796static void __exit mtk_cpufreq_driver_exit(void)
797{
798	platform_device_unregister(cpufreq_pdev);
799	platform_driver_unregister(&mtk_cpufreq_platdrv);
800}
801module_exit(mtk_cpufreq_driver_exit)
802
803MODULE_DESCRIPTION("MediaTek CPUFreq driver");
804MODULE_AUTHOR("Pi-Cheng Chen <pi-cheng.chen@linaro.org>");
805MODULE_LICENSE("GPL v2");
v5.14.15
  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/module.h>
 12#include <linux/of.h>
 
 13#include <linux/platform_device.h>
 14#include <linux/pm_opp.h>
 15#include <linux/regulator/consumer.h>
 16#include <linux/slab.h>
 17#include <linux/thermal.h>
 18
 19#define MIN_VOLT_SHIFT		(100000)
 20#define MAX_VOLT_SHIFT		(200000)
 21#define MAX_VOLT_LIMIT		(1150000)
 22#define VOLT_TOL		(10000)
 
 
 
 
 23
 24/*
 25 * The struct mtk_cpu_dvfs_info holds necessary information for doing CPU DVFS
 26 * on each CPU power/clock domain of Mediatek SoCs. Each CPU cluster in
 27 * Mediatek SoCs has two voltage inputs, Vproc and Vsram. In some cases the two
 28 * voltage inputs need to be controlled under a hardware limitation:
 29 * 100mV < Vsram - Vproc < 200mV
 30 *
 31 * When scaling the clock frequency of a CPU clock domain, the clock source
 32 * needs to be switched to another stable PLL clock temporarily until
 33 * the original PLL becomes stable at target frequency.
 34 */
 35struct mtk_cpu_dvfs_info {
 36	struct cpumask cpus;
 37	struct device *cpu_dev;
 
 38	struct regulator *proc_reg;
 39	struct regulator *sram_reg;
 40	struct clk *cpu_clk;
 41	struct clk *inter_clk;
 42	struct list_head list_head;
 43	int intermediate_voltage;
 44	bool need_voltage_tracking;
 
 
 
 
 
 
 
 
 
 
 45};
 46
 
 
 47static LIST_HEAD(dvfs_info_list);
 48
 49static struct mtk_cpu_dvfs_info *mtk_cpu_dvfs_info_lookup(int cpu)
 50{
 51	struct mtk_cpu_dvfs_info *info;
 52
 53	list_for_each_entry(info, &dvfs_info_list, list_head) {
 54		if (cpumask_test_cpu(cpu, &info->cpus))
 55			return info;
 56	}
 57
 58	return NULL;
 59}
 60
 61static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
 62					int new_vproc)
 63{
 
 64	struct regulator *proc_reg = info->proc_reg;
 65	struct regulator *sram_reg = info->sram_reg;
 66	int old_vproc, old_vsram, new_vsram, vsram, vproc, ret;
 67
 68	old_vproc = regulator_get_voltage(proc_reg);
 69	if (old_vproc < 0) {
 70		pr_err("%s: invalid Vproc value: %d\n", __func__, old_vproc);
 71		return old_vproc;
 72	}
 73	/* Vsram should not exceed the maximum allowed voltage of SoC. */
 74	new_vsram = min(new_vproc + MIN_VOLT_SHIFT, MAX_VOLT_LIMIT);
 75
 76	if (old_vproc < new_vproc) {
 77		/*
 78		 * When scaling up voltages, Vsram and Vproc scale up step
 79		 * by step. At each step, set Vsram to (Vproc + 200mV) first,
 80		 * then set Vproc to (Vsram - 100mV).
 81		 * Keep doing it until Vsram and Vproc hit target voltages.
 82		 */
 83		do {
 84			old_vsram = regulator_get_voltage(sram_reg);
 85			if (old_vsram < 0) {
 86				pr_err("%s: invalid Vsram value: %d\n",
 87				       __func__, old_vsram);
 88				return old_vsram;
 89			}
 90			old_vproc = regulator_get_voltage(proc_reg);
 91			if (old_vproc < 0) {
 92				pr_err("%s: invalid Vproc value: %d\n",
 93				       __func__, old_vproc);
 94				return old_vproc;
 95			}
 96
 97			vsram = min(new_vsram, old_vproc + MAX_VOLT_SHIFT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 98
 99			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {
100				vsram = MAX_VOLT_LIMIT;
101
102				/*
103				 * If the target Vsram hits the maximum voltage,
104				 * try to set the exact voltage value first.
105				 */
106				ret = regulator_set_voltage(sram_reg, vsram,
107							    vsram);
108				if (ret)
109					ret = regulator_set_voltage(sram_reg,
110							vsram - VOLT_TOL,
111							vsram);
112
 
 
113				vproc = new_vproc;
114			} else {
115				ret = regulator_set_voltage(sram_reg, vsram,
116							    vsram + VOLT_TOL);
117
118				vproc = vsram - MIN_VOLT_SHIFT;
119			}
120			if (ret)
121				return ret;
122
123			ret = regulator_set_voltage(proc_reg, vproc,
124						    vproc + VOLT_TOL);
125			if (ret) {
126				regulator_set_voltage(sram_reg, old_vsram,
127						      old_vsram);
128				return ret;
129			}
130		} while (vproc < new_vproc || vsram < new_vsram);
131	} else if (old_vproc > new_vproc) {
132		/*
133		 * When scaling down voltages, Vsram and Vproc scale down step
134		 * by step. At each step, set Vproc to (Vsram - 200mV) first,
135		 * then set Vproc to (Vproc + 100mV).
136		 * Keep doing it until Vsram and Vproc hit target voltages.
137		 */
138		do {
139			old_vproc = regulator_get_voltage(proc_reg);
140			if (old_vproc < 0) {
141				pr_err("%s: invalid Vproc value: %d\n",
142				       __func__, old_vproc);
143				return old_vproc;
144			}
145			old_vsram = regulator_get_voltage(sram_reg);
146			if (old_vsram < 0) {
147				pr_err("%s: invalid Vsram value: %d\n",
148				       __func__, old_vsram);
149				return old_vsram;
150			}
151
152			vproc = max(new_vproc, old_vsram - MAX_VOLT_SHIFT);
153			ret = regulator_set_voltage(proc_reg, vproc,
154						    vproc + VOLT_TOL);
155			if (ret)
156				return ret;
157
158			if (vproc == new_vproc)
159				vsram = new_vsram;
160			else
161				vsram = max(new_vsram, vproc + MIN_VOLT_SHIFT);
162
163			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {
164				vsram = MAX_VOLT_LIMIT;
165
166				/*
167				 * If the target Vsram hits the maximum voltage,
168				 * try to set the exact voltage value first.
169				 */
170				ret = regulator_set_voltage(sram_reg, vsram,
171							    vsram);
172				if (ret)
173					ret = regulator_set_voltage(sram_reg,
174							vsram - VOLT_TOL,
175							vsram);
176			} else {
177				ret = regulator_set_voltage(sram_reg, vsram,
178							    vsram + VOLT_TOL);
179			}
180
 
 
181			if (ret) {
182				regulator_set_voltage(proc_reg, old_vproc,
183						      old_vproc);
184				return ret;
185			}
186		} while (vproc > new_vproc + VOLT_TOL ||
187			 vsram > new_vsram + VOLT_TOL);
188	}
 
 
 
 
 
 
 
 
189
190	return 0;
191}
192
193static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
194{
 
 
 
195	if (info->need_voltage_tracking)
196		return mtk_cpufreq_voltage_tracking(info, vproc);
197	else
198		return regulator_set_voltage(info->proc_reg, vproc,
199					     vproc + VOLT_TOL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
200}
201
202static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
203				  unsigned int index)
204{
205	struct cpufreq_frequency_table *freq_table = policy->freq_table;
206	struct clk *cpu_clk = policy->clk;
207	struct clk *armpll = clk_get_parent(cpu_clk);
208	struct mtk_cpu_dvfs_info *info = policy->driver_data;
209	struct device *cpu_dev = info->cpu_dev;
210	struct dev_pm_opp *opp;
211	long freq_hz, old_freq_hz;
212	int vproc, old_vproc, inter_vproc, target_vproc, ret;
213
214	inter_vproc = info->intermediate_voltage;
215
216	old_freq_hz = clk_get_rate(cpu_clk);
217	old_vproc = regulator_get_voltage(info->proc_reg);
218	if (old_vproc < 0) {
219		pr_err("%s: invalid Vproc value: %d\n", __func__, old_vproc);
220		return old_vproc;
 
 
 
 
 
 
 
 
221	}
222
223	freq_hz = freq_table[index].frequency * 1000;
224
225	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
226	if (IS_ERR(opp)) {
227		pr_err("cpu%d: failed to find OPP for %ld\n",
228		       policy->cpu, freq_hz);
229		return PTR_ERR(opp);
 
230	}
231	vproc = dev_pm_opp_get_voltage(opp);
232	dev_pm_opp_put(opp);
233
234	/*
 
 
 
 
 
 
 
 
235	 * If the new voltage or the intermediate voltage is higher than the
236	 * current voltage, scale up voltage first.
237	 */
238	target_vproc = (inter_vproc > vproc) ? inter_vproc : vproc;
239	if (old_vproc < target_vproc) {
240		ret = mtk_cpufreq_set_voltage(info, target_vproc);
241		if (ret) {
242			pr_err("cpu%d: failed to scale up voltage!\n",
243			       policy->cpu);
244			mtk_cpufreq_set_voltage(info, old_vproc);
245			return ret;
246		}
247	}
248
249	/* Reparent the CPU clock to intermediate clock. */
250	ret = clk_set_parent(cpu_clk, info->inter_clk);
251	if (ret) {
252		pr_err("cpu%d: failed to re-parent cpu clock!\n",
253		       policy->cpu);
254		mtk_cpufreq_set_voltage(info, old_vproc);
255		WARN_ON(1);
256		return ret;
257	}
258
259	/* Set the original PLL to target rate. */
260	ret = clk_set_rate(armpll, freq_hz);
261	if (ret) {
262		pr_err("cpu%d: failed to scale cpu clock rate!\n",
263		       policy->cpu);
264		clk_set_parent(cpu_clk, armpll);
265		mtk_cpufreq_set_voltage(info, old_vproc);
266		return ret;
267	}
268
269	/* Set parent of CPU clock back to the original PLL. */
270	ret = clk_set_parent(cpu_clk, armpll);
271	if (ret) {
272		pr_err("cpu%d: failed to re-parent cpu clock!\n",
273		       policy->cpu);
274		mtk_cpufreq_set_voltage(info, inter_vproc);
275		WARN_ON(1);
276		return ret;
277	}
278
279	/*
280	 * If the new voltage is lower than the intermediate voltage or the
281	 * original voltage, scale down to the new voltage.
282	 */
283	if (vproc < inter_vproc || vproc < old_vproc) {
284		ret = mtk_cpufreq_set_voltage(info, vproc);
285		if (ret) {
286			pr_err("cpu%d: failed to scale down voltage!\n",
287			       policy->cpu);
288			clk_set_parent(cpu_clk, info->inter_clk);
289			clk_set_rate(armpll, old_freq_hz);
290			clk_set_parent(cpu_clk, armpll);
291			return ret;
292		}
293	}
294
295	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
296}
297
298#define DYNAMIC_POWER "dynamic-power-coefficient"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
299
300static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
301{
302	struct device *cpu_dev;
303	struct regulator *proc_reg = ERR_PTR(-ENODEV);
304	struct regulator *sram_reg = ERR_PTR(-ENODEV);
305	struct clk *cpu_clk = ERR_PTR(-ENODEV);
306	struct clk *inter_clk = ERR_PTR(-ENODEV);
307	struct dev_pm_opp *opp;
308	unsigned long rate;
309	int ret;
310
311	cpu_dev = get_cpu_device(cpu);
312	if (!cpu_dev) {
313		pr_err("failed to get cpu%d device\n", cpu);
314		return -ENODEV;
315	}
 
316
317	cpu_clk = clk_get(cpu_dev, "cpu");
318	if (IS_ERR(cpu_clk)) {
319		if (PTR_ERR(cpu_clk) == -EPROBE_DEFER)
320			pr_warn("cpu clk for cpu%d not ready, retry.\n", cpu);
321		else
322			pr_err("failed to get cpu clk for cpu%d\n", cpu);
323
324		ret = PTR_ERR(cpu_clk);
325		return ret;
326	}
327
328	inter_clk = clk_get(cpu_dev, "intermediate");
329	if (IS_ERR(inter_clk)) {
330		if (PTR_ERR(inter_clk) == -EPROBE_DEFER)
331			pr_warn("intermediate clk for cpu%d not ready, retry.\n",
332				cpu);
333		else
334			pr_err("failed to get intermediate clk for cpu%d\n",
335			       cpu);
336
337		ret = PTR_ERR(inter_clk);
338		goto out_free_resources;
 
 
 
 
 
 
 
 
 
 
339	}
340
341	proc_reg = regulator_get_optional(cpu_dev, "proc");
342	if (IS_ERR(proc_reg)) {
343		if (PTR_ERR(proc_reg) == -EPROBE_DEFER)
344			pr_warn("proc regulator for cpu%d not ready, retry.\n",
345				cpu);
346		else
347			pr_err("failed to get proc regulator for cpu%d\n",
348			       cpu);
349
350		ret = PTR_ERR(proc_reg);
351		goto out_free_resources;
352	}
353
354	/* Both presence and absence of sram regulator are valid cases. */
355	sram_reg = regulator_get_exclusive(cpu_dev, "sram");
 
 
 
 
 
 
 
 
 
 
 
 
 
356
357	/* Get OPP-sharing information from "operating-points-v2" bindings */
358	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, &info->cpus);
359	if (ret) {
360		pr_err("failed to get OPP-sharing information for cpu%d\n",
361		       cpu);
362		goto out_free_resources;
363	}
364
365	ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
366	if (ret) {
367		pr_warn("no OPP table for cpu%d\n", cpu);
368		goto out_free_resources;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
369	}
370
371	/* Search a safe voltage for intermediate frequency. */
372	rate = clk_get_rate(inter_clk);
373	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
374	if (IS_ERR(opp)) {
375		pr_err("failed to get intermediate opp for cpu%d\n", cpu);
376		ret = PTR_ERR(opp);
377		goto out_free_opp_table;
378	}
379	info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
380	dev_pm_opp_put(opp);
381
382	info->cpu_dev = cpu_dev;
383	info->proc_reg = proc_reg;
384	info->sram_reg = IS_ERR(sram_reg) ? NULL : sram_reg;
385	info->cpu_clk = cpu_clk;
386	info->inter_clk = inter_clk;
 
 
 
 
 
387
388	/*
389	 * If SRAM regulator is present, software "voltage tracking" is needed
390	 * for this CPU power domain.
391	 */
392	info->need_voltage_tracking = !IS_ERR(sram_reg);
 
 
 
 
 
 
 
 
 
393
394	return 0;
395
 
 
 
 
 
 
396out_free_opp_table:
397	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
398
399out_free_resources:
400	if (!IS_ERR(proc_reg))
401		regulator_put(proc_reg);
402	if (!IS_ERR(sram_reg))
403		regulator_put(sram_reg);
404	if (!IS_ERR(cpu_clk))
405		clk_put(cpu_clk);
406	if (!IS_ERR(inter_clk))
407		clk_put(inter_clk);
 
 
 
 
 
 
 
 
 
 
408
409	return ret;
410}
411
412static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
413{
414	if (!IS_ERR(info->proc_reg))
415		regulator_put(info->proc_reg);
416	if (!IS_ERR(info->sram_reg))
 
417		regulator_put(info->sram_reg);
418	if (!IS_ERR(info->cpu_clk))
419		clk_put(info->cpu_clk);
420	if (!IS_ERR(info->inter_clk))
421		clk_put(info->inter_clk);
422
423	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
 
424}
425
426static int mtk_cpufreq_init(struct cpufreq_policy *policy)
427{
428	struct mtk_cpu_dvfs_info *info;
429	struct cpufreq_frequency_table *freq_table;
430	int ret;
431
432	info = mtk_cpu_dvfs_info_lookup(policy->cpu);
433	if (!info) {
434		pr_err("dvfs info for cpu%d is not initialized.\n",
435		       policy->cpu);
436		return -EINVAL;
437	}
438
439	ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
440	if (ret) {
441		pr_err("failed to init cpufreq table for cpu%d: %d\n",
442		       policy->cpu, ret);
 
443		return ret;
444	}
445
446	cpumask_copy(policy->cpus, &info->cpus);
447	policy->freq_table = freq_table;
448	policy->driver_data = info;
449	policy->clk = info->cpu_clk;
450
451	dev_pm_opp_of_register_em(info->cpu_dev, policy->cpus);
452
453	return 0;
454}
455
456static int mtk_cpufreq_exit(struct cpufreq_policy *policy)
457{
458	struct mtk_cpu_dvfs_info *info = policy->driver_data;
459
460	dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
461
462	return 0;
463}
464
465static struct cpufreq_driver mtk_cpufreq_driver = {
466	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
467		 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
468		 CPUFREQ_IS_COOLING_DEV,
469	.verify = cpufreq_generic_frequency_table_verify,
470	.target_index = mtk_cpufreq_set_target,
471	.get = cpufreq_generic_get,
472	.init = mtk_cpufreq_init,
473	.exit = mtk_cpufreq_exit,
 
474	.name = "mtk-cpufreq",
475	.attr = cpufreq_generic_attr,
476};
477
478static int mtk_cpufreq_probe(struct platform_device *pdev)
479{
 
480	struct mtk_cpu_dvfs_info *info, *tmp;
481	int cpu, ret;
482
 
 
 
 
 
 
 
483	for_each_possible_cpu(cpu) {
484		info = mtk_cpu_dvfs_info_lookup(cpu);
485		if (info)
486			continue;
487
488		info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
489		if (!info) {
490			ret = -ENOMEM;
491			goto release_dvfs_info_list;
492		}
493
 
494		ret = mtk_cpu_dvfs_info_init(info, cpu);
495		if (ret) {
496			dev_err(&pdev->dev,
497				"failed to initialize dvfs info for cpu%d\n",
498				cpu);
499			goto release_dvfs_info_list;
500		}
501
502		list_add(&info->list_head, &dvfs_info_list);
503	}
504
505	ret = cpufreq_register_driver(&mtk_cpufreq_driver);
506	if (ret) {
507		dev_err(&pdev->dev, "failed to register mtk cpufreq driver\n");
508		goto release_dvfs_info_list;
509	}
510
511	return 0;
512
513release_dvfs_info_list:
514	list_for_each_entry_safe(info, tmp, &dvfs_info_list, list_head) {
515		mtk_cpu_dvfs_info_release(info);
516		list_del(&info->list_head);
517	}
518
519	return ret;
520}
521
522static struct platform_driver mtk_cpufreq_platdrv = {
523	.driver = {
524		.name	= "mtk-cpufreq",
525	},
526	.probe		= mtk_cpufreq_probe,
527};
528
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
529/* List of machines supported by this driver */
530static const struct of_device_id mtk_cpufreq_machines[] __initconst = {
531	{ .compatible = "mediatek,mt2701", },
532	{ .compatible = "mediatek,mt2712", },
533	{ .compatible = "mediatek,mt7622", },
534	{ .compatible = "mediatek,mt7623", },
535	{ .compatible = "mediatek,mt8167", },
536	{ .compatible = "mediatek,mt817x", },
537	{ .compatible = "mediatek,mt8173", },
538	{ .compatible = "mediatek,mt8176", },
539	{ .compatible = "mediatek,mt8183", },
540	{ .compatible = "mediatek,mt8365", },
541	{ .compatible = "mediatek,mt8516", },
542
543	{ }
544};
545MODULE_DEVICE_TABLE(of, mtk_cpufreq_machines);
546
547static int __init mtk_cpufreq_driver_init(void)
548{
549	struct device_node *np;
550	const struct of_device_id *match;
551	struct platform_device *pdev;
552	int err;
553
554	np = of_find_node_by_path("/");
555	if (!np)
556		return -ENODEV;
557
558	match = of_match_node(mtk_cpufreq_machines, np);
559	of_node_put(np);
560	if (!match) {
561		pr_debug("Machine is not compatible with mtk-cpufreq\n");
562		return -ENODEV;
563	}
 
564
565	err = platform_driver_register(&mtk_cpufreq_platdrv);
566	if (err)
567		return err;
568
569	/*
570	 * Since there's no place to hold device registration code and no
571	 * device tree based way to match cpufreq driver yet, both the driver
572	 * and the device registration codes are put here to handle defer
573	 * probing.
574	 */
575	pdev = platform_device_register_simple("mtk-cpufreq", -1, NULL, 0);
576	if (IS_ERR(pdev)) {
 
577		pr_err("failed to register mtk-cpufreq platform device\n");
578		platform_driver_unregister(&mtk_cpufreq_platdrv);
579		return PTR_ERR(pdev);
580	}
581
582	return 0;
583}
584device_initcall(mtk_cpufreq_driver_init);
 
 
 
 
 
 
 
585
586MODULE_DESCRIPTION("MediaTek CPUFreq driver");
587MODULE_AUTHOR("Pi-Cheng Chen <pi-cheng.chen@linaro.org>");
588MODULE_LICENSE("GPL v2");