xref: /linux/drivers/cpufreq/qcom-cpufreq-hw.c (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/clk-provider.h>
8 #include <linux/cpufreq.h>
9 #include <linux/init.h>
10 #include <linux/interconnect.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_opp.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/units.h>
21 
22 #define LUT_MAX_ENTRIES			40U
23 #define LUT_SRC				GENMASK(31, 30)
24 #define LUT_L_VAL			GENMASK(7, 0)
25 #define LUT_CORE_COUNT			GENMASK(18, 16)
26 #define LUT_VOLT			GENMASK(11, 0)
27 #define CLK_HW_DIV			2
28 #define LUT_TURBO_IND			1
29 
30 #define GT_IRQ_STATUS			BIT(2)
31 
32 #define MAX_FREQ_DOMAINS		4
33 
34 struct qcom_cpufreq_soc_data {
35 	u32 reg_enable;
36 	u32 reg_domain_state;
37 	u32 reg_dcvs_ctrl;
38 	u32 reg_freq_lut;
39 	u32 reg_volt_lut;
40 	u32 reg_intr_clr;
41 	u32 reg_current_vote;
42 	u32 reg_perf_state;
43 	u8 lut_row_size;
44 };
45 
46 struct qcom_cpufreq_data {
47 	void __iomem *base;
48 
49 	/*
50 	 * Mutex to synchronize between de-init sequence and re-starting LMh
51 	 * polling/interrupts
52 	 */
53 	struct mutex throttle_lock;
54 	int throttle_irq;
55 	char irq_name[15];
56 	bool cancel_throttle;
57 	struct delayed_work throttle_work;
58 	struct cpufreq_policy *policy;
59 	struct clk_hw cpu_clk;
60 
61 	bool per_core_dcvs;
62 };
63 
64 static struct {
65 	struct qcom_cpufreq_data *data;
66 	const struct qcom_cpufreq_soc_data *soc_data;
67 } qcom_cpufreq;
68 
69 static unsigned long cpu_hw_rate, xo_rate;
70 static bool icc_scaling_enabled;
71 
72 static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
73 			       unsigned long freq_khz)
74 {
75 	unsigned long freq_hz = freq_khz * 1000;
76 	struct dev_pm_opp *opp;
77 	struct device *dev;
78 	int ret;
79 
80 	dev = get_cpu_device(policy->cpu);
81 	if (!dev)
82 		return -ENODEV;
83 
84 	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
85 	if (IS_ERR(opp))
86 		return PTR_ERR(opp);
87 
88 	ret = dev_pm_opp_set_opp(dev, opp);
89 	dev_pm_opp_put(opp);
90 	return ret;
91 }
92 
93 static int qcom_cpufreq_update_opp(struct device *cpu_dev,
94 				   unsigned long freq_khz,
95 				   unsigned long volt)
96 {
97 	unsigned long freq_hz = freq_khz * 1000;
98 	int ret;
99 
100 	/* Skip voltage update if the opp table is not available */
101 	if (!icc_scaling_enabled)
102 		return dev_pm_opp_add(cpu_dev, freq_hz, volt);
103 
104 	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
105 	if (ret) {
106 		dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
107 		return ret;
108 	}
109 
110 	return dev_pm_opp_enable(cpu_dev, freq_hz);
111 }
112 
113 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
114 					unsigned int index)
115 {
116 	struct qcom_cpufreq_data *data = policy->driver_data;
117 	const struct qcom_cpufreq_soc_data *soc_data = qcom_cpufreq.soc_data;
118 	unsigned long freq = policy->freq_table[index].frequency;
119 	unsigned int i;
120 
121 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
122 
123 	if (data->per_core_dcvs)
124 		for (i = 1; i < cpumask_weight(policy->related_cpus); i++)
125 			writel_relaxed(index, data->base + soc_data->reg_perf_state + i * 4);
126 
127 	if (icc_scaling_enabled)
128 		qcom_cpufreq_set_bw(policy, freq);
129 
130 	return 0;
131 }
132 
133 static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
134 {
135 	unsigned int lval;
136 
137 	if (qcom_cpufreq.soc_data->reg_current_vote)
138 		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_current_vote) & 0x3ff;
139 	else
140 		lval = readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_domain_state) & 0xff;
141 
142 	return lval * xo_rate;
143 }
144 
145 /* Get the frequency requested by the cpufreq core for the CPU */
146 static unsigned int qcom_cpufreq_get_freq(struct cpufreq_policy *policy)
147 {
148 	struct qcom_cpufreq_data *data;
149 	const struct qcom_cpufreq_soc_data *soc_data;
150 	unsigned int index;
151 
152 	if (!policy)
153 		return 0;
154 
155 	data = policy->driver_data;
156 	soc_data = qcom_cpufreq.soc_data;
157 
158 	index = readl_relaxed(data->base + soc_data->reg_perf_state);
159 	index = min(index, LUT_MAX_ENTRIES - 1);
160 
161 	return policy->freq_table[index].frequency;
162 }
163 
164 static unsigned int __qcom_cpufreq_hw_get(struct cpufreq_policy *policy)
165 {
166 	struct qcom_cpufreq_data *data;
167 
168 	if (!policy)
169 		return 0;
170 
171 	data = policy->driver_data;
172 
173 	if (data->throttle_irq >= 0)
174 		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
175 
176 	return qcom_cpufreq_get_freq(policy);
177 }
178 
179 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
180 {
181 	return __qcom_cpufreq_hw_get(cpufreq_cpu_get_raw(cpu));
182 }
183 
184 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
185 						unsigned int target_freq)
186 {
187 	struct qcom_cpufreq_data *data = policy->driver_data;
188 	const struct qcom_cpufreq_soc_data *soc_data = qcom_cpufreq.soc_data;
189 	unsigned int index;
190 	unsigned int i;
191 
192 	index = policy->cached_resolved_idx;
193 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
194 
195 	if (data->per_core_dcvs)
196 		for (i = 1; i < cpumask_weight(policy->related_cpus); i++)
197 			writel_relaxed(index, data->base + soc_data->reg_perf_state + i * 4);
198 
199 	return policy->freq_table[index].frequency;
200 }
201 
202 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
203 				    struct cpufreq_policy *policy)
204 {
205 	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
206 	u32 volt;
207 	struct cpufreq_frequency_table	*table;
208 	struct dev_pm_opp *opp;
209 	unsigned long rate;
210 	int ret;
211 	struct qcom_cpufreq_data *drv_data = policy->driver_data;
212 	const struct qcom_cpufreq_soc_data *soc_data = qcom_cpufreq.soc_data;
213 
214 	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
215 	if (!table)
216 		return -ENOMEM;
217 
218 	ret = dev_pm_opp_of_add_table(cpu_dev);
219 	if (!ret) {
220 		/* Disable all opps and cross-validate against LUT later */
221 		icc_scaling_enabled = true;
222 		for (rate = 0; ; rate++) {
223 			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
224 			if (IS_ERR(opp))
225 				break;
226 
227 			dev_pm_opp_put(opp);
228 			dev_pm_opp_disable(cpu_dev, rate);
229 		}
230 	} else if (ret != -ENODEV) {
231 		dev_err(cpu_dev, "Invalid opp table in device tree\n");
232 		kfree(table);
233 		return ret;
234 	} else {
235 		policy->fast_switch_possible = true;
236 		icc_scaling_enabled = false;
237 	}
238 
239 	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
240 		data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
241 				      i * soc_data->lut_row_size);
242 		src = FIELD_GET(LUT_SRC, data);
243 		lval = FIELD_GET(LUT_L_VAL, data);
244 		core_count = FIELD_GET(LUT_CORE_COUNT, data);
245 
246 		data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
247 				      i * soc_data->lut_row_size);
248 		volt = FIELD_GET(LUT_VOLT, data) * 1000;
249 
250 		if (src)
251 			freq = xo_rate * lval / 1000;
252 		else
253 			freq = cpu_hw_rate / 1000;
254 
255 		if (freq != prev_freq && core_count != LUT_TURBO_IND) {
256 			if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
257 				table[i].frequency = freq;
258 				dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
259 				freq, core_count);
260 			} else {
261 				dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
262 				table[i].frequency = CPUFREQ_ENTRY_INVALID;
263 			}
264 
265 		} else if (core_count == LUT_TURBO_IND) {
266 			table[i].frequency = CPUFREQ_ENTRY_INVALID;
267 		}
268 
269 		/*
270 		 * Two of the same frequencies with the same core counts means
271 		 * end of table
272 		 */
273 		if (i > 0 && prev_freq == freq) {
274 			struct cpufreq_frequency_table *prev = &table[i - 1];
275 
276 			/*
277 			 * Only treat the last frequency that might be a boost
278 			 * as the boost frequency
279 			 */
280 			if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
281 				if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
282 					prev->frequency = prev_freq;
283 					prev->flags = CPUFREQ_BOOST_FREQ;
284 				} else {
285 					dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
286 						 freq);
287 				}
288 			}
289 
290 			break;
291 		}
292 
293 		prev_freq = freq;
294 	}
295 
296 	table[i].frequency = CPUFREQ_TABLE_END;
297 	policy->freq_table = table;
298 	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
299 
300 	return 0;
301 }
302 
303 static void qcom_get_related_cpus(int index, struct cpumask *m)
304 {
305 	struct device_node *cpu_np;
306 	struct of_phandle_args args;
307 	int cpu, ret;
308 
309 	for_each_possible_cpu(cpu) {
310 		cpu_np = of_cpu_device_node_get(cpu);
311 		if (!cpu_np)
312 			continue;
313 
314 		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
315 						 "#freq-domain-cells", 0,
316 						 &args);
317 		of_node_put(cpu_np);
318 		if (ret < 0)
319 			continue;
320 
321 		if (index == args.args[0])
322 			cpumask_set_cpu(cpu, m);
323 	}
324 }
325 
326 static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
327 {
328 	struct cpufreq_policy *policy = data->policy;
329 	int cpu = cpumask_first(policy->related_cpus);
330 	struct device *dev = get_cpu_device(cpu);
331 	unsigned long freq_hz, throttled_freq;
332 	struct dev_pm_opp *opp;
333 
334 	/*
335 	 * Get the h/w throttled frequency, normalize it using the
336 	 * registered opp table and use it to calculate thermal pressure.
337 	 */
338 	freq_hz = qcom_lmh_get_throttle_freq(data);
339 
340 	opp = dev_pm_opp_find_freq_floor(dev, &freq_hz);
341 	if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE)
342 		opp = dev_pm_opp_find_freq_ceil(dev, &freq_hz);
343 
344 	if (IS_ERR(opp)) {
345 		dev_warn(dev, "Can't find the OPP for throttling: %pe!\n", opp);
346 	} else {
347 		dev_pm_opp_put(opp);
348 	}
349 
350 	throttled_freq = freq_hz / HZ_PER_KHZ;
351 
352 	/* Update HW pressure (the boost frequencies are accepted) */
353 	arch_update_hw_pressure(policy->related_cpus, throttled_freq);
354 
355 	/*
356 	 * In the unlikely case policy is unregistered do not enable
357 	 * polling or h/w interrupt
358 	 */
359 	mutex_lock(&data->throttle_lock);
360 	if (data->cancel_throttle)
361 		goto out;
362 
363 	/*
364 	 * If h/w throttled frequency is higher than what cpufreq has requested
365 	 * for, then stop polling and switch back to interrupt mechanism.
366 	 */
367 	if (throttled_freq >= qcom_cpufreq_get_freq(cpufreq_cpu_get_raw(cpu)))
368 		enable_irq(data->throttle_irq);
369 	else
370 		mod_delayed_work(system_highpri_wq, &data->throttle_work,
371 				 msecs_to_jiffies(10));
372 
373 out:
374 	mutex_unlock(&data->throttle_lock);
375 }
376 
377 static void qcom_lmh_dcvs_poll(struct work_struct *work)
378 {
379 	struct qcom_cpufreq_data *data;
380 
381 	data = container_of(work, struct qcom_cpufreq_data, throttle_work.work);
382 	qcom_lmh_dcvs_notify(data);
383 }
384 
385 static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data)
386 {
387 	struct qcom_cpufreq_data *c_data = data;
388 
389 	/* Disable interrupt and enable polling */
390 	disable_irq_nosync(c_data->throttle_irq);
391 	schedule_delayed_work(&c_data->throttle_work, 0);
392 
393 	if (qcom_cpufreq.soc_data->reg_intr_clr)
394 		writel_relaxed(GT_IRQ_STATUS,
395 			       c_data->base + qcom_cpufreq.soc_data->reg_intr_clr);
396 
397 	return IRQ_HANDLED;
398 }
399 
400 static const struct qcom_cpufreq_soc_data qcom_soc_data = {
401 	.reg_enable = 0x0,
402 	.reg_dcvs_ctrl = 0xbc,
403 	.reg_freq_lut = 0x110,
404 	.reg_volt_lut = 0x114,
405 	.reg_current_vote = 0x704,
406 	.reg_perf_state = 0x920,
407 	.lut_row_size = 32,
408 };
409 
410 static const struct qcom_cpufreq_soc_data epss_soc_data = {
411 	.reg_enable = 0x0,
412 	.reg_domain_state = 0x20,
413 	.reg_dcvs_ctrl = 0xb0,
414 	.reg_freq_lut = 0x100,
415 	.reg_volt_lut = 0x200,
416 	.reg_intr_clr = 0x308,
417 	.reg_perf_state = 0x320,
418 	.lut_row_size = 4,
419 };
420 
421 static const struct of_device_id qcom_cpufreq_hw_match[] = {
422 	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
423 	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
424 	{}
425 };
426 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
427 
428 static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)
429 {
430 	struct qcom_cpufreq_data *data = policy->driver_data;
431 	struct platform_device *pdev = cpufreq_get_driver_data();
432 	int ret;
433 
434 	/*
435 	 * Look for LMh interrupt. If no interrupt line is specified /
436 	 * if there is an error, allow cpufreq to be enabled as usual.
437 	 */
438 	data->throttle_irq = platform_get_irq_optional(pdev, index);
439 	if (data->throttle_irq == -ENXIO)
440 		return 0;
441 	if (data->throttle_irq < 0)
442 		return data->throttle_irq;
443 
444 	data->cancel_throttle = false;
445 
446 	mutex_init(&data->throttle_lock);
447 	INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll);
448 
449 	snprintf(data->irq_name, sizeof(data->irq_name), "dcvsh-irq-%u", policy->cpu);
450 	ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq,
451 				   IRQF_ONESHOT | IRQF_NO_AUTOEN, data->irq_name, data);
452 	if (ret) {
453 		dev_err(&pdev->dev, "Error registering %s: %d\n", data->irq_name, ret);
454 		return 0;
455 	}
456 
457 	ret = irq_set_affinity_and_hint(data->throttle_irq, policy->cpus);
458 	if (ret)
459 		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
460 			data->irq_name, data->throttle_irq);
461 
462 	return 0;
463 }
464 
465 static int qcom_cpufreq_hw_cpu_online(struct cpufreq_policy *policy)
466 {
467 	struct qcom_cpufreq_data *data = policy->driver_data;
468 	struct platform_device *pdev = cpufreq_get_driver_data();
469 	int ret;
470 
471 	if (data->throttle_irq <= 0)
472 		return 0;
473 
474 	mutex_lock(&data->throttle_lock);
475 	data->cancel_throttle = false;
476 	mutex_unlock(&data->throttle_lock);
477 
478 	ret = irq_set_affinity_and_hint(data->throttle_irq, policy->cpus);
479 	if (ret)
480 		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
481 			data->irq_name, data->throttle_irq);
482 
483 	return ret;
484 }
485 
486 static int qcom_cpufreq_hw_cpu_offline(struct cpufreq_policy *policy)
487 {
488 	struct qcom_cpufreq_data *data = policy->driver_data;
489 
490 	if (data->throttle_irq <= 0)
491 		return 0;
492 
493 	mutex_lock(&data->throttle_lock);
494 	data->cancel_throttle = true;
495 	mutex_unlock(&data->throttle_lock);
496 
497 	cancel_delayed_work_sync(&data->throttle_work);
498 	irq_set_affinity_and_hint(data->throttle_irq, NULL);
499 	disable_irq_nosync(data->throttle_irq);
500 
501 	return 0;
502 }
503 
504 static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data)
505 {
506 	if (data->throttle_irq <= 0)
507 		return;
508 
509 	free_irq(data->throttle_irq, data);
510 }
511 
512 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
513 {
514 	struct platform_device *pdev = cpufreq_get_driver_data();
515 	struct device *dev = &pdev->dev;
516 	struct of_phandle_args args;
517 	struct device_node *cpu_np;
518 	struct device *cpu_dev;
519 	struct qcom_cpufreq_data *data;
520 	int ret, index;
521 
522 	cpu_dev = get_cpu_device(policy->cpu);
523 	if (!cpu_dev) {
524 		pr_err("%s: failed to get cpu%d device\n", __func__,
525 		       policy->cpu);
526 		return -ENODEV;
527 	}
528 
529 	cpu_np = of_cpu_device_node_get(policy->cpu);
530 	if (!cpu_np)
531 		return -EINVAL;
532 
533 	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
534 					 "#freq-domain-cells", 0, &args);
535 	of_node_put(cpu_np);
536 	if (ret)
537 		return ret;
538 
539 	index = args.args[0];
540 	data = &qcom_cpufreq.data[index];
541 
542 	/* HW should be in enabled state to proceed */
543 	if (!(readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_enable) & 0x1)) {
544 		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
545 		return -ENODEV;
546 	}
547 
548 	if (readl_relaxed(data->base + qcom_cpufreq.soc_data->reg_dcvs_ctrl) & 0x1)
549 		data->per_core_dcvs = true;
550 
551 	qcom_get_related_cpus(index, policy->cpus);
552 
553 	policy->driver_data = data;
554 	policy->dvfs_possible_from_any_cpu = true;
555 	data->policy = policy;
556 
557 	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
558 	if (ret) {
559 		dev_err(dev, "Domain-%d failed to read LUT\n", index);
560 		return ret;
561 	}
562 
563 	ret = dev_pm_opp_get_opp_count(cpu_dev);
564 	if (ret <= 0) {
565 		dev_err(cpu_dev, "Failed to add OPPs\n");
566 		return -ENODEV;
567 	}
568 
569 	if (policy_has_boost_freq(policy)) {
570 		ret = cpufreq_enable_boost_support();
571 		if (ret)
572 			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
573 	}
574 
575 	return qcom_cpufreq_hw_lmh_init(policy, index);
576 }
577 
578 static void qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
579 {
580 	struct device *cpu_dev = get_cpu_device(policy->cpu);
581 	struct qcom_cpufreq_data *data = policy->driver_data;
582 
583 	dev_pm_opp_remove_all_dynamic(cpu_dev);
584 	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
585 	qcom_cpufreq_hw_lmh_exit(data);
586 	kfree(policy->freq_table);
587 	kfree(data);
588 }
589 
590 static void qcom_cpufreq_ready(struct cpufreq_policy *policy)
591 {
592 	struct qcom_cpufreq_data *data = policy->driver_data;
593 
594 	if (data->throttle_irq >= 0)
595 		enable_irq(data->throttle_irq);
596 }
597 
598 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
599 	&cpufreq_freq_attr_scaling_available_freqs,
600 	&cpufreq_freq_attr_scaling_boost_freqs,
601 	NULL
602 };
603 
604 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
605 	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK |
606 			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
607 			  CPUFREQ_IS_COOLING_DEV,
608 	.verify		= cpufreq_generic_frequency_table_verify,
609 	.target_index	= qcom_cpufreq_hw_target_index,
610 	.get		= qcom_cpufreq_hw_get,
611 	.init		= qcom_cpufreq_hw_cpu_init,
612 	.exit		= qcom_cpufreq_hw_cpu_exit,
613 	.online		= qcom_cpufreq_hw_cpu_online,
614 	.offline	= qcom_cpufreq_hw_cpu_offline,
615 	.register_em	= cpufreq_register_em_with_opp,
616 	.fast_switch    = qcom_cpufreq_hw_fast_switch,
617 	.name		= "qcom-cpufreq-hw",
618 	.attr		= qcom_cpufreq_hw_attr,
619 	.ready		= qcom_cpufreq_ready,
620 };
621 
622 static unsigned long qcom_cpufreq_hw_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
623 {
624 	struct qcom_cpufreq_data *data = container_of(hw, struct qcom_cpufreq_data, cpu_clk);
625 
626 	return __qcom_cpufreq_hw_get(data->policy) * HZ_PER_KHZ;
627 }
628 
629 /*
630  * Since we cannot determine the closest rate of the target rate, let's just
631  * return the actual rate at which the clock is running at. This is needed to
632  * make clk_set_rate() API work properly.
633  */
634 static int qcom_cpufreq_hw_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
635 {
636 	req->rate = qcom_cpufreq_hw_recalc_rate(hw, 0);
637 
638 	return 0;
639 }
640 
641 static const struct clk_ops qcom_cpufreq_hw_clk_ops = {
642 	.recalc_rate = qcom_cpufreq_hw_recalc_rate,
643 	.determine_rate = qcom_cpufreq_hw_determine_rate,
644 };
645 
646 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
647 {
648 	struct clk_hw_onecell_data *clk_data;
649 	struct device *dev = &pdev->dev;
650 	struct device *cpu_dev;
651 	struct clk *clk;
652 	int ret, i, num_domains;
653 
654 	clk = clk_get(dev, "xo");
655 	if (IS_ERR(clk))
656 		return PTR_ERR(clk);
657 
658 	xo_rate = clk_get_rate(clk);
659 	clk_put(clk);
660 
661 	clk = clk_get(dev, "alternate");
662 	if (IS_ERR(clk))
663 		return PTR_ERR(clk);
664 
665 	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
666 	clk_put(clk);
667 
668 	cpufreq_qcom_hw_driver.driver_data = pdev;
669 
670 	/* Check for optional interconnect paths on CPU0 */
671 	cpu_dev = get_cpu_device(0);
672 	if (!cpu_dev)
673 		return -EPROBE_DEFER;
674 
675 	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
676 	if (ret)
677 		return dev_err_probe(dev, ret, "Failed to find icc paths\n");
678 
679 	for (num_domains = 0; num_domains < MAX_FREQ_DOMAINS; num_domains++)
680 		if (!platform_get_resource(pdev, IORESOURCE_MEM, num_domains))
681 			break;
682 
683 	qcom_cpufreq.data = devm_kzalloc(dev, sizeof(struct qcom_cpufreq_data) * num_domains,
684 					 GFP_KERNEL);
685 	if (!qcom_cpufreq.data)
686 		return -ENOMEM;
687 
688 	qcom_cpufreq.soc_data = of_device_get_match_data(dev);
689 	if (!qcom_cpufreq.soc_data)
690 		return -ENODEV;
691 
692 	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, num_domains), GFP_KERNEL);
693 	if (!clk_data)
694 		return -ENOMEM;
695 
696 	clk_data->num = num_domains;
697 
698 	for (i = 0; i < num_domains; i++) {
699 		struct qcom_cpufreq_data *data = &qcom_cpufreq.data[i];
700 		struct clk_init_data clk_init = {};
701 		void __iomem *base;
702 
703 		base = devm_platform_ioremap_resource(pdev, i);
704 		if (IS_ERR(base)) {
705 			dev_err(dev, "Failed to map resource index %d\n", i);
706 			return PTR_ERR(base);
707 		}
708 
709 		data->base = base;
710 
711 		/* Register CPU clock for each frequency domain */
712 		clk_init.name = kasprintf(GFP_KERNEL, "qcom_cpufreq%d", i);
713 		if (!clk_init.name)
714 			return -ENOMEM;
715 
716 		clk_init.flags = CLK_GET_RATE_NOCACHE;
717 		clk_init.ops = &qcom_cpufreq_hw_clk_ops;
718 		data->cpu_clk.init = &clk_init;
719 
720 		ret = devm_clk_hw_register(dev, &data->cpu_clk);
721 		if (ret < 0) {
722 			dev_err(dev, "Failed to register clock %d: %d\n", i, ret);
723 			kfree(clk_init.name);
724 			return ret;
725 		}
726 
727 		clk_data->hws[i] = &data->cpu_clk;
728 		kfree(clk_init.name);
729 	}
730 
731 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
732 	if (ret < 0) {
733 		dev_err(dev, "Failed to add clock provider\n");
734 		return ret;
735 	}
736 
737 	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
738 	if (ret)
739 		dev_err(dev, "CPUFreq HW driver failed to register\n");
740 	else
741 		dev_dbg(dev, "QCOM CPUFreq HW driver initialized\n");
742 
743 	return ret;
744 }
745 
746 static void qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
747 {
748 	cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
749 }
750 
751 static struct platform_driver qcom_cpufreq_hw_driver = {
752 	.probe = qcom_cpufreq_hw_driver_probe,
753 	.remove = qcom_cpufreq_hw_driver_remove,
754 	.driver = {
755 		.name = "qcom-cpufreq-hw",
756 		.of_match_table = qcom_cpufreq_hw_match,
757 	},
758 };
759 
760 static int __init qcom_cpufreq_hw_init(void)
761 {
762 	return platform_driver_register(&qcom_cpufreq_hw_driver);
763 }
764 postcore_initcall(qcom_cpufreq_hw_init);
765 
766 static void __exit qcom_cpufreq_hw_exit(void)
767 {
768 	platform_driver_unregister(&qcom_cpufreq_hw_driver);
769 }
770 module_exit(qcom_cpufreq_hw_exit);
771 
772 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
773 MODULE_LICENSE("GPL v2");
774