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/cpufreq.h>
8 #include <linux/init.h>
9 #include <linux/interconnect.h>
10 #include <linux/interrupt.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/of_address.h>
14 #include <linux/of_platform.h>
15 #include <linux/pm_opp.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
18 
19 #define LUT_MAX_ENTRIES			40U
20 #define LUT_SRC				GENMASK(31, 30)
21 #define LUT_L_VAL			GENMASK(7, 0)
22 #define LUT_CORE_COUNT			GENMASK(18, 16)
23 #define LUT_VOLT			GENMASK(11, 0)
24 #define CLK_HW_DIV			2
25 #define LUT_TURBO_IND			1
26 
27 #define HZ_PER_KHZ			1000
28 
29 struct qcom_cpufreq_soc_data {
30 	u32 reg_enable;
31 	u32 reg_freq_lut;
32 	u32 reg_volt_lut;
33 	u32 reg_current_vote;
34 	u32 reg_perf_state;
35 	u8 lut_row_size;
36 };
37 
38 struct qcom_cpufreq_data {
39 	void __iomem *base;
40 	struct resource *res;
41 	const struct qcom_cpufreq_soc_data *soc_data;
42 
43 	/*
44 	 * Mutex to synchronize between de-init sequence and re-starting LMh
45 	 * polling/interrupts
46 	 */
47 	struct mutex throttle_lock;
48 	int throttle_irq;
49 	char irq_name[15];
50 	bool cancel_throttle;
51 	struct delayed_work throttle_work;
52 	struct cpufreq_policy *policy;
53 };
54 
55 static unsigned long cpu_hw_rate, xo_rate;
56 static bool icc_scaling_enabled;
57 
58 static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
59 			       unsigned long freq_khz)
60 {
61 	unsigned long freq_hz = freq_khz * 1000;
62 	struct dev_pm_opp *opp;
63 	struct device *dev;
64 	int ret;
65 
66 	dev = get_cpu_device(policy->cpu);
67 	if (!dev)
68 		return -ENODEV;
69 
70 	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
71 	if (IS_ERR(opp))
72 		return PTR_ERR(opp);
73 
74 	ret = dev_pm_opp_set_opp(dev, opp);
75 	dev_pm_opp_put(opp);
76 	return ret;
77 }
78 
79 static int qcom_cpufreq_update_opp(struct device *cpu_dev,
80 				   unsigned long freq_khz,
81 				   unsigned long volt)
82 {
83 	unsigned long freq_hz = freq_khz * 1000;
84 	int ret;
85 
86 	/* Skip voltage update if the opp table is not available */
87 	if (!icc_scaling_enabled)
88 		return dev_pm_opp_add(cpu_dev, freq_hz, volt);
89 
90 	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
91 	if (ret) {
92 		dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
93 		return ret;
94 	}
95 
96 	return dev_pm_opp_enable(cpu_dev, freq_hz);
97 }
98 
99 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
100 					unsigned int index)
101 {
102 	struct qcom_cpufreq_data *data = policy->driver_data;
103 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
104 	unsigned long freq = policy->freq_table[index].frequency;
105 
106 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
107 
108 	if (icc_scaling_enabled)
109 		qcom_cpufreq_set_bw(policy, freq);
110 
111 	return 0;
112 }
113 
114 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
115 {
116 	struct qcom_cpufreq_data *data;
117 	const struct qcom_cpufreq_soc_data *soc_data;
118 	struct cpufreq_policy *policy;
119 	unsigned int index;
120 
121 	policy = cpufreq_cpu_get_raw(cpu);
122 	if (!policy)
123 		return 0;
124 
125 	data = policy->driver_data;
126 	soc_data = data->soc_data;
127 
128 	index = readl_relaxed(data->base + soc_data->reg_perf_state);
129 	index = min(index, LUT_MAX_ENTRIES - 1);
130 
131 	return policy->freq_table[index].frequency;
132 }
133 
134 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
135 						unsigned int target_freq)
136 {
137 	struct qcom_cpufreq_data *data = policy->driver_data;
138 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
139 	unsigned int index;
140 
141 	index = policy->cached_resolved_idx;
142 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
143 
144 	return policy->freq_table[index].frequency;
145 }
146 
147 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
148 				    struct cpufreq_policy *policy)
149 {
150 	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
151 	u32 volt;
152 	struct cpufreq_frequency_table	*table;
153 	struct dev_pm_opp *opp;
154 	unsigned long rate;
155 	int ret;
156 	struct qcom_cpufreq_data *drv_data = policy->driver_data;
157 	const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;
158 
159 	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
160 	if (!table)
161 		return -ENOMEM;
162 
163 	ret = dev_pm_opp_of_add_table(cpu_dev);
164 	if (!ret) {
165 		/* Disable all opps and cross-validate against LUT later */
166 		icc_scaling_enabled = true;
167 		for (rate = 0; ; rate++) {
168 			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
169 			if (IS_ERR(opp))
170 				break;
171 
172 			dev_pm_opp_put(opp);
173 			dev_pm_opp_disable(cpu_dev, rate);
174 		}
175 	} else if (ret != -ENODEV) {
176 		dev_err(cpu_dev, "Invalid opp table in device tree\n");
177 		return ret;
178 	} else {
179 		policy->fast_switch_possible = true;
180 		icc_scaling_enabled = false;
181 	}
182 
183 	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
184 		data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
185 				      i * soc_data->lut_row_size);
186 		src = FIELD_GET(LUT_SRC, data);
187 		lval = FIELD_GET(LUT_L_VAL, data);
188 		core_count = FIELD_GET(LUT_CORE_COUNT, data);
189 
190 		data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
191 				      i * soc_data->lut_row_size);
192 		volt = FIELD_GET(LUT_VOLT, data) * 1000;
193 
194 		if (src)
195 			freq = xo_rate * lval / 1000;
196 		else
197 			freq = cpu_hw_rate / 1000;
198 
199 		if (freq != prev_freq && core_count != LUT_TURBO_IND) {
200 			if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
201 				table[i].frequency = freq;
202 				dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
203 				freq, core_count);
204 			} else {
205 				dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
206 				table[i].frequency = CPUFREQ_ENTRY_INVALID;
207 			}
208 
209 		} else if (core_count == LUT_TURBO_IND) {
210 			table[i].frequency = CPUFREQ_ENTRY_INVALID;
211 		}
212 
213 		/*
214 		 * Two of the same frequencies with the same core counts means
215 		 * end of table
216 		 */
217 		if (i > 0 && prev_freq == freq) {
218 			struct cpufreq_frequency_table *prev = &table[i - 1];
219 
220 			/*
221 			 * Only treat the last frequency that might be a boost
222 			 * as the boost frequency
223 			 */
224 			if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
225 				if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
226 					prev->frequency = prev_freq;
227 					prev->flags = CPUFREQ_BOOST_FREQ;
228 				} else {
229 					dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
230 						 freq);
231 				}
232 			}
233 
234 			break;
235 		}
236 
237 		prev_freq = freq;
238 	}
239 
240 	table[i].frequency = CPUFREQ_TABLE_END;
241 	policy->freq_table = table;
242 	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
243 
244 	return 0;
245 }
246 
247 static void qcom_get_related_cpus(int index, struct cpumask *m)
248 {
249 	struct device_node *cpu_np;
250 	struct of_phandle_args args;
251 	int cpu, ret;
252 
253 	for_each_possible_cpu(cpu) {
254 		cpu_np = of_cpu_device_node_get(cpu);
255 		if (!cpu_np)
256 			continue;
257 
258 		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
259 						 "#freq-domain-cells", 0,
260 						 &args);
261 		of_node_put(cpu_np);
262 		if (ret < 0)
263 			continue;
264 
265 		if (index == args.args[0])
266 			cpumask_set_cpu(cpu, m);
267 	}
268 }
269 
270 static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
271 {
272 	unsigned int val = readl_relaxed(data->base + data->soc_data->reg_current_vote);
273 
274 	return (val & 0x3FF) * 19200;
275 }
276 
277 static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
278 {
279 	struct cpufreq_policy *policy = data->policy;
280 	int cpu = cpumask_first(policy->cpus);
281 	struct device *dev = get_cpu_device(cpu);
282 	unsigned long freq_hz, throttled_freq;
283 	struct dev_pm_opp *opp;
284 	unsigned int freq;
285 
286 	/*
287 	 * Get the h/w throttled frequency, normalize it using the
288 	 * registered opp table and use it to calculate thermal pressure.
289 	 */
290 	freq = qcom_lmh_get_throttle_freq(data);
291 	freq_hz = freq * HZ_PER_KHZ;
292 
293 	opp = dev_pm_opp_find_freq_floor(dev, &freq_hz);
294 	if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE)
295 		dev_pm_opp_find_freq_ceil(dev, &freq_hz);
296 
297 	throttled_freq = freq_hz / HZ_PER_KHZ;
298 
299 	/* Update thermal pressure (the boost frequencies are accepted) */
300 	arch_update_thermal_pressure(policy->related_cpus, throttled_freq);
301 
302 	/*
303 	 * In the unlikely case policy is unregistered do not enable
304 	 * polling or h/w interrupt
305 	 */
306 	mutex_lock(&data->throttle_lock);
307 	if (data->cancel_throttle)
308 		goto out;
309 
310 	/*
311 	 * If h/w throttled frequency is higher than what cpufreq has requested
312 	 * for, then stop polling and switch back to interrupt mechanism.
313 	 */
314 	if (throttled_freq >= qcom_cpufreq_hw_get(cpu))
315 		enable_irq(data->throttle_irq);
316 	else
317 		mod_delayed_work(system_highpri_wq, &data->throttle_work,
318 				 msecs_to_jiffies(10));
319 
320 out:
321 	mutex_unlock(&data->throttle_lock);
322 }
323 
324 static void qcom_lmh_dcvs_poll(struct work_struct *work)
325 {
326 	struct qcom_cpufreq_data *data;
327 
328 	data = container_of(work, struct qcom_cpufreq_data, throttle_work.work);
329 	qcom_lmh_dcvs_notify(data);
330 }
331 
332 static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data)
333 {
334 	struct qcom_cpufreq_data *c_data = data;
335 
336 	/* Disable interrupt and enable polling */
337 	disable_irq_nosync(c_data->throttle_irq);
338 	schedule_delayed_work(&c_data->throttle_work, 0);
339 
340 	return IRQ_HANDLED;
341 }
342 
343 static const struct qcom_cpufreq_soc_data qcom_soc_data = {
344 	.reg_enable = 0x0,
345 	.reg_freq_lut = 0x110,
346 	.reg_volt_lut = 0x114,
347 	.reg_current_vote = 0x704,
348 	.reg_perf_state = 0x920,
349 	.lut_row_size = 32,
350 };
351 
352 static const struct qcom_cpufreq_soc_data epss_soc_data = {
353 	.reg_enable = 0x0,
354 	.reg_freq_lut = 0x100,
355 	.reg_volt_lut = 0x200,
356 	.reg_perf_state = 0x320,
357 	.lut_row_size = 4,
358 };
359 
360 static const struct of_device_id qcom_cpufreq_hw_match[] = {
361 	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
362 	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
363 	{}
364 };
365 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
366 
367 static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)
368 {
369 	struct qcom_cpufreq_data *data = policy->driver_data;
370 	struct platform_device *pdev = cpufreq_get_driver_data();
371 	int ret;
372 
373 	/*
374 	 * Look for LMh interrupt. If no interrupt line is specified /
375 	 * if there is an error, allow cpufreq to be enabled as usual.
376 	 */
377 	data->throttle_irq = platform_get_irq_optional(pdev, index);
378 	if (data->throttle_irq == -ENXIO)
379 		return 0;
380 	if (data->throttle_irq < 0)
381 		return data->throttle_irq;
382 
383 	data->cancel_throttle = false;
384 	data->policy = policy;
385 
386 	mutex_init(&data->throttle_lock);
387 	INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll);
388 
389 	snprintf(data->irq_name, sizeof(data->irq_name), "dcvsh-irq-%u", policy->cpu);
390 	ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq,
391 				   IRQF_ONESHOT | IRQF_NO_AUTOEN, data->irq_name, data);
392 	if (ret) {
393 		dev_err(&pdev->dev, "Error registering %s: %d\n", data->irq_name, ret);
394 		return 0;
395 	}
396 
397 	ret = irq_set_affinity_hint(data->throttle_irq, policy->cpus);
398 	if (ret)
399 		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
400 			data->irq_name, data->throttle_irq);
401 
402 	return 0;
403 }
404 
405 static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data)
406 {
407 	if (data->throttle_irq <= 0)
408 		return;
409 
410 	mutex_lock(&data->throttle_lock);
411 	data->cancel_throttle = true;
412 	mutex_unlock(&data->throttle_lock);
413 
414 	cancel_delayed_work_sync(&data->throttle_work);
415 	free_irq(data->throttle_irq, data);
416 }
417 
418 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
419 {
420 	struct platform_device *pdev = cpufreq_get_driver_data();
421 	struct device *dev = &pdev->dev;
422 	struct of_phandle_args args;
423 	struct device_node *cpu_np;
424 	struct device *cpu_dev;
425 	struct resource *res;
426 	void __iomem *base;
427 	struct qcom_cpufreq_data *data;
428 	int ret, index;
429 
430 	cpu_dev = get_cpu_device(policy->cpu);
431 	if (!cpu_dev) {
432 		pr_err("%s: failed to get cpu%d device\n", __func__,
433 		       policy->cpu);
434 		return -ENODEV;
435 	}
436 
437 	cpu_np = of_cpu_device_node_get(policy->cpu);
438 	if (!cpu_np)
439 		return -EINVAL;
440 
441 	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
442 					 "#freq-domain-cells", 0, &args);
443 	of_node_put(cpu_np);
444 	if (ret)
445 		return ret;
446 
447 	index = args.args[0];
448 
449 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
450 	if (!res) {
451 		dev_err(dev, "failed to get mem resource %d\n", index);
452 		return -ENODEV;
453 	}
454 
455 	if (!request_mem_region(res->start, resource_size(res), res->name)) {
456 		dev_err(dev, "failed to request resource %pR\n", res);
457 		return -EBUSY;
458 	}
459 
460 	base = ioremap(res->start, resource_size(res));
461 	if (!base) {
462 		dev_err(dev, "failed to map resource %pR\n", res);
463 		ret = -ENOMEM;
464 		goto release_region;
465 	}
466 
467 	data = kzalloc(sizeof(*data), GFP_KERNEL);
468 	if (!data) {
469 		ret = -ENOMEM;
470 		goto unmap_base;
471 	}
472 
473 	data->soc_data = of_device_get_match_data(&pdev->dev);
474 	data->base = base;
475 	data->res = res;
476 
477 	/* HW should be in enabled state to proceed */
478 	if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
479 		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
480 		ret = -ENODEV;
481 		goto error;
482 	}
483 
484 	qcom_get_related_cpus(index, policy->cpus);
485 	if (!cpumask_weight(policy->cpus)) {
486 		dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
487 		ret = -ENOENT;
488 		goto error;
489 	}
490 
491 	policy->driver_data = data;
492 	policy->dvfs_possible_from_any_cpu = true;
493 
494 	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
495 	if (ret) {
496 		dev_err(dev, "Domain-%d failed to read LUT\n", index);
497 		goto error;
498 	}
499 
500 	ret = dev_pm_opp_get_opp_count(cpu_dev);
501 	if (ret <= 0) {
502 		dev_err(cpu_dev, "Failed to add OPPs\n");
503 		ret = -ENODEV;
504 		goto error;
505 	}
506 
507 	if (policy_has_boost_freq(policy)) {
508 		ret = cpufreq_enable_boost_support();
509 		if (ret)
510 			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
511 	}
512 
513 	ret = qcom_cpufreq_hw_lmh_init(policy, index);
514 	if (ret)
515 		goto error;
516 
517 	return 0;
518 error:
519 	kfree(data);
520 unmap_base:
521 	iounmap(base);
522 release_region:
523 	release_mem_region(res->start, resource_size(res));
524 	return ret;
525 }
526 
527 static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
528 {
529 	struct device *cpu_dev = get_cpu_device(policy->cpu);
530 	struct qcom_cpufreq_data *data = policy->driver_data;
531 	struct resource *res = data->res;
532 	void __iomem *base = data->base;
533 
534 	dev_pm_opp_remove_all_dynamic(cpu_dev);
535 	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
536 	qcom_cpufreq_hw_lmh_exit(data);
537 	kfree(policy->freq_table);
538 	kfree(data);
539 	iounmap(base);
540 	release_mem_region(res->start, resource_size(res));
541 
542 	return 0;
543 }
544 
545 static void qcom_cpufreq_ready(struct cpufreq_policy *policy)
546 {
547 	struct qcom_cpufreq_data *data = policy->driver_data;
548 
549 	if (data->throttle_irq >= 0)
550 		enable_irq(data->throttle_irq);
551 }
552 
553 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
554 	&cpufreq_freq_attr_scaling_available_freqs,
555 	&cpufreq_freq_attr_scaling_boost_freqs,
556 	NULL
557 };
558 
559 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
560 	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK |
561 			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
562 			  CPUFREQ_IS_COOLING_DEV,
563 	.verify		= cpufreq_generic_frequency_table_verify,
564 	.target_index	= qcom_cpufreq_hw_target_index,
565 	.get		= qcom_cpufreq_hw_get,
566 	.init		= qcom_cpufreq_hw_cpu_init,
567 	.exit		= qcom_cpufreq_hw_cpu_exit,
568 	.register_em	= cpufreq_register_em_with_opp,
569 	.fast_switch    = qcom_cpufreq_hw_fast_switch,
570 	.name		= "qcom-cpufreq-hw",
571 	.attr		= qcom_cpufreq_hw_attr,
572 	.ready		= qcom_cpufreq_ready,
573 };
574 
575 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
576 {
577 	struct device *cpu_dev;
578 	struct clk *clk;
579 	int ret;
580 
581 	clk = clk_get(&pdev->dev, "xo");
582 	if (IS_ERR(clk))
583 		return PTR_ERR(clk);
584 
585 	xo_rate = clk_get_rate(clk);
586 	clk_put(clk);
587 
588 	clk = clk_get(&pdev->dev, "alternate");
589 	if (IS_ERR(clk))
590 		return PTR_ERR(clk);
591 
592 	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
593 	clk_put(clk);
594 
595 	cpufreq_qcom_hw_driver.driver_data = pdev;
596 
597 	/* Check for optional interconnect paths on CPU0 */
598 	cpu_dev = get_cpu_device(0);
599 	if (!cpu_dev)
600 		return -EPROBE_DEFER;
601 
602 	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
603 	if (ret)
604 		return ret;
605 
606 	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
607 	if (ret)
608 		dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
609 	else
610 		dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
611 
612 	return ret;
613 }
614 
615 static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
616 {
617 	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
618 }
619 
620 static struct platform_driver qcom_cpufreq_hw_driver = {
621 	.probe = qcom_cpufreq_hw_driver_probe,
622 	.remove = qcom_cpufreq_hw_driver_remove,
623 	.driver = {
624 		.name = "qcom-cpufreq-hw",
625 		.of_match_table = qcom_cpufreq_hw_match,
626 	},
627 };
628 
629 static int __init qcom_cpufreq_hw_init(void)
630 {
631 	return platform_driver_register(&qcom_cpufreq_hw_driver);
632 }
633 postcore_initcall(qcom_cpufreq_hw_init);
634 
635 static void __exit qcom_cpufreq_hw_exit(void)
636 {
637 	platform_driver_unregister(&qcom_cpufreq_hw_driver);
638 }
639 module_exit(qcom_cpufreq_hw_exit);
640 
641 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
642 MODULE_LICENSE("GPL v2");
643