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