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/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of_address.h>
13 #include <linux/of_platform.h>
14 #include <linux/pm_opp.h>
15 #include <linux/slab.h>
16 
17 #define LUT_MAX_ENTRIES			40U
18 #define LUT_SRC				GENMASK(31, 30)
19 #define LUT_L_VAL			GENMASK(7, 0)
20 #define LUT_CORE_COUNT			GENMASK(18, 16)
21 #define LUT_VOLT			GENMASK(11, 0)
22 #define CLK_HW_DIV			2
23 #define LUT_TURBO_IND			1
24 
25 struct qcom_cpufreq_soc_data {
26 	u32 reg_enable;
27 	u32 reg_freq_lut;
28 	u32 reg_volt_lut;
29 	u32 reg_perf_state;
30 	u8 lut_row_size;
31 };
32 
33 struct qcom_cpufreq_data {
34 	void __iomem *base;
35 	struct resource *res;
36 	const struct qcom_cpufreq_soc_data *soc_data;
37 };
38 
39 static unsigned long cpu_hw_rate, xo_rate;
40 static bool icc_scaling_enabled;
41 
42 static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
43 			       unsigned long freq_khz)
44 {
45 	unsigned long freq_hz = freq_khz * 1000;
46 	struct dev_pm_opp *opp;
47 	struct device *dev;
48 	int ret;
49 
50 	dev = get_cpu_device(policy->cpu);
51 	if (!dev)
52 		return -ENODEV;
53 
54 	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
55 	if (IS_ERR(opp))
56 		return PTR_ERR(opp);
57 
58 	ret = dev_pm_opp_set_opp(dev, opp);
59 	dev_pm_opp_put(opp);
60 	return ret;
61 }
62 
63 static int qcom_cpufreq_update_opp(struct device *cpu_dev,
64 				   unsigned long freq_khz,
65 				   unsigned long volt)
66 {
67 	unsigned long freq_hz = freq_khz * 1000;
68 	int ret;
69 
70 	/* Skip voltage update if the opp table is not available */
71 	if (!icc_scaling_enabled)
72 		return dev_pm_opp_add(cpu_dev, freq_hz, volt);
73 
74 	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
75 	if (ret) {
76 		dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
77 		return ret;
78 	}
79 
80 	return dev_pm_opp_enable(cpu_dev, freq_hz);
81 }
82 
83 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
84 					unsigned int index)
85 {
86 	struct qcom_cpufreq_data *data = policy->driver_data;
87 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
88 	unsigned long freq = policy->freq_table[index].frequency;
89 
90 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
91 
92 	if (icc_scaling_enabled)
93 		qcom_cpufreq_set_bw(policy, freq);
94 
95 	return 0;
96 }
97 
98 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
99 {
100 	struct qcom_cpufreq_data *data;
101 	const struct qcom_cpufreq_soc_data *soc_data;
102 	struct cpufreq_policy *policy;
103 	unsigned int index;
104 
105 	policy = cpufreq_cpu_get_raw(cpu);
106 	if (!policy)
107 		return 0;
108 
109 	data = policy->driver_data;
110 	soc_data = data->soc_data;
111 
112 	index = readl_relaxed(data->base + soc_data->reg_perf_state);
113 	index = min(index, LUT_MAX_ENTRIES - 1);
114 
115 	return policy->freq_table[index].frequency;
116 }
117 
118 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
119 						unsigned int target_freq)
120 {
121 	struct qcom_cpufreq_data *data = policy->driver_data;
122 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
123 	unsigned int index;
124 
125 	index = policy->cached_resolved_idx;
126 	writel_relaxed(index, data->base + soc_data->reg_perf_state);
127 
128 	return policy->freq_table[index].frequency;
129 }
130 
131 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
132 				    struct cpufreq_policy *policy)
133 {
134 	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
135 	u32 volt;
136 	struct cpufreq_frequency_table	*table;
137 	struct dev_pm_opp *opp;
138 	unsigned long rate;
139 	int ret;
140 	struct qcom_cpufreq_data *drv_data = policy->driver_data;
141 	const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;
142 
143 	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
144 	if (!table)
145 		return -ENOMEM;
146 
147 	ret = dev_pm_opp_of_add_table(cpu_dev);
148 	if (!ret) {
149 		/* Disable all opps and cross-validate against LUT later */
150 		icc_scaling_enabled = true;
151 		for (rate = 0; ; rate++) {
152 			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
153 			if (IS_ERR(opp))
154 				break;
155 
156 			dev_pm_opp_put(opp);
157 			dev_pm_opp_disable(cpu_dev, rate);
158 		}
159 	} else if (ret != -ENODEV) {
160 		dev_err(cpu_dev, "Invalid opp table in device tree\n");
161 		return ret;
162 	} else {
163 		policy->fast_switch_possible = true;
164 		icc_scaling_enabled = false;
165 	}
166 
167 	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
168 		data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
169 				      i * soc_data->lut_row_size);
170 		src = FIELD_GET(LUT_SRC, data);
171 		lval = FIELD_GET(LUT_L_VAL, data);
172 		core_count = FIELD_GET(LUT_CORE_COUNT, data);
173 
174 		data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
175 				      i * soc_data->lut_row_size);
176 		volt = FIELD_GET(LUT_VOLT, data) * 1000;
177 
178 		if (src)
179 			freq = xo_rate * lval / 1000;
180 		else
181 			freq = cpu_hw_rate / 1000;
182 
183 		if (freq != prev_freq && core_count != LUT_TURBO_IND) {
184 			if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
185 				table[i].frequency = freq;
186 				dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
187 				freq, core_count);
188 			} else {
189 				dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
190 				table[i].frequency = CPUFREQ_ENTRY_INVALID;
191 			}
192 
193 		} else if (core_count == LUT_TURBO_IND) {
194 			table[i].frequency = CPUFREQ_ENTRY_INVALID;
195 		}
196 
197 		/*
198 		 * Two of the same frequencies with the same core counts means
199 		 * end of table
200 		 */
201 		if (i > 0 && prev_freq == freq) {
202 			struct cpufreq_frequency_table *prev = &table[i - 1];
203 
204 			/*
205 			 * Only treat the last frequency that might be a boost
206 			 * as the boost frequency
207 			 */
208 			if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
209 				if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
210 					prev->frequency = prev_freq;
211 					prev->flags = CPUFREQ_BOOST_FREQ;
212 				} else {
213 					dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
214 						 freq);
215 				}
216 			}
217 
218 			break;
219 		}
220 
221 		prev_freq = freq;
222 	}
223 
224 	table[i].frequency = CPUFREQ_TABLE_END;
225 	policy->freq_table = table;
226 	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
227 
228 	return 0;
229 }
230 
231 static void qcom_get_related_cpus(int index, struct cpumask *m)
232 {
233 	struct device_node *cpu_np;
234 	struct of_phandle_args args;
235 	int cpu, ret;
236 
237 	for_each_possible_cpu(cpu) {
238 		cpu_np = of_cpu_device_node_get(cpu);
239 		if (!cpu_np)
240 			continue;
241 
242 		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
243 						 "#freq-domain-cells", 0,
244 						 &args);
245 		of_node_put(cpu_np);
246 		if (ret < 0)
247 			continue;
248 
249 		if (index == args.args[0])
250 			cpumask_set_cpu(cpu, m);
251 	}
252 }
253 
254 static const struct qcom_cpufreq_soc_data qcom_soc_data = {
255 	.reg_enable = 0x0,
256 	.reg_freq_lut = 0x110,
257 	.reg_volt_lut = 0x114,
258 	.reg_perf_state = 0x920,
259 	.lut_row_size = 32,
260 };
261 
262 static const struct qcom_cpufreq_soc_data epss_soc_data = {
263 	.reg_enable = 0x0,
264 	.reg_freq_lut = 0x100,
265 	.reg_volt_lut = 0x200,
266 	.reg_perf_state = 0x320,
267 	.lut_row_size = 4,
268 };
269 
270 static const struct of_device_id qcom_cpufreq_hw_match[] = {
271 	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
272 	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
273 	{}
274 };
275 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);
276 
277 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
278 {
279 	struct platform_device *pdev = cpufreq_get_driver_data();
280 	struct device *dev = &pdev->dev;
281 	struct of_phandle_args args;
282 	struct device_node *cpu_np;
283 	struct device *cpu_dev;
284 	struct resource *res;
285 	void __iomem *base;
286 	struct qcom_cpufreq_data *data;
287 	int ret, index;
288 
289 	cpu_dev = get_cpu_device(policy->cpu);
290 	if (!cpu_dev) {
291 		pr_err("%s: failed to get cpu%d device\n", __func__,
292 		       policy->cpu);
293 		return -ENODEV;
294 	}
295 
296 	cpu_np = of_cpu_device_node_get(policy->cpu);
297 	if (!cpu_np)
298 		return -EINVAL;
299 
300 	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
301 					 "#freq-domain-cells", 0, &args);
302 	of_node_put(cpu_np);
303 	if (ret)
304 		return ret;
305 
306 	index = args.args[0];
307 
308 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
309 	if (!res) {
310 		dev_err(dev, "failed to get mem resource %d\n", index);
311 		return -ENODEV;
312 	}
313 
314 	if (!request_mem_region(res->start, resource_size(res), res->name)) {
315 		dev_err(dev, "failed to request resource %pR\n", res);
316 		return -EBUSY;
317 	}
318 
319 	base = ioremap(res->start, resource_size(res));
320 	if (IS_ERR(base)) {
321 		dev_err(dev, "failed to map resource %pR\n", res);
322 		ret = PTR_ERR(base);
323 		goto release_region;
324 	}
325 
326 	data = kzalloc(sizeof(*data), GFP_KERNEL);
327 	if (!data) {
328 		ret = -ENOMEM;
329 		goto unmap_base;
330 	}
331 
332 	data->soc_data = of_device_get_match_data(&pdev->dev);
333 	data->base = base;
334 	data->res = res;
335 
336 	/* HW should be in enabled state to proceed */
337 	if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
338 		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
339 		ret = -ENODEV;
340 		goto error;
341 	}
342 
343 	qcom_get_related_cpus(index, policy->cpus);
344 	if (!cpumask_weight(policy->cpus)) {
345 		dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
346 		ret = -ENOENT;
347 		goto error;
348 	}
349 
350 	policy->driver_data = data;
351 
352 	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
353 	if (ret) {
354 		dev_err(dev, "Domain-%d failed to read LUT\n", index);
355 		goto error;
356 	}
357 
358 	ret = dev_pm_opp_get_opp_count(cpu_dev);
359 	if (ret <= 0) {
360 		dev_err(cpu_dev, "Failed to add OPPs\n");
361 		ret = -ENODEV;
362 		goto error;
363 	}
364 
365 	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
366 
367 	if (policy_has_boost_freq(policy)) {
368 		ret = cpufreq_enable_boost_support();
369 		if (ret)
370 			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
371 	}
372 
373 	return 0;
374 error:
375 	kfree(data);
376 unmap_base:
377 	iounmap(data->base);
378 release_region:
379 	release_mem_region(res->start, resource_size(res));
380 	return ret;
381 }
382 
383 static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
384 {
385 	struct device *cpu_dev = get_cpu_device(policy->cpu);
386 	struct qcom_cpufreq_data *data = policy->driver_data;
387 	struct resource *res = data->res;
388 	void __iomem *base = data->base;
389 
390 	dev_pm_opp_remove_all_dynamic(cpu_dev);
391 	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
392 	kfree(policy->freq_table);
393 	kfree(data);
394 	iounmap(base);
395 	release_mem_region(res->start, resource_size(res));
396 
397 	return 0;
398 }
399 
400 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
401 	&cpufreq_freq_attr_scaling_available_freqs,
402 	&cpufreq_freq_attr_scaling_boost_freqs,
403 	NULL
404 };
405 
406 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
407 	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK |
408 			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
409 			  CPUFREQ_IS_COOLING_DEV,
410 	.verify		= cpufreq_generic_frequency_table_verify,
411 	.target_index	= qcom_cpufreq_hw_target_index,
412 	.get		= qcom_cpufreq_hw_get,
413 	.init		= qcom_cpufreq_hw_cpu_init,
414 	.exit		= qcom_cpufreq_hw_cpu_exit,
415 	.fast_switch    = qcom_cpufreq_hw_fast_switch,
416 	.name		= "qcom-cpufreq-hw",
417 	.attr		= qcom_cpufreq_hw_attr,
418 };
419 
420 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
421 {
422 	struct device *cpu_dev;
423 	struct clk *clk;
424 	int ret;
425 
426 	clk = clk_get(&pdev->dev, "xo");
427 	if (IS_ERR(clk))
428 		return PTR_ERR(clk);
429 
430 	xo_rate = clk_get_rate(clk);
431 	clk_put(clk);
432 
433 	clk = clk_get(&pdev->dev, "alternate");
434 	if (IS_ERR(clk))
435 		return PTR_ERR(clk);
436 
437 	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
438 	clk_put(clk);
439 
440 	cpufreq_qcom_hw_driver.driver_data = pdev;
441 
442 	/* Check for optional interconnect paths on CPU0 */
443 	cpu_dev = get_cpu_device(0);
444 	if (!cpu_dev)
445 		return -EPROBE_DEFER;
446 
447 	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
448 	if (ret)
449 		return ret;
450 
451 	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
452 	if (ret)
453 		dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
454 	else
455 		dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
456 
457 	return ret;
458 }
459 
460 static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
461 {
462 	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
463 }
464 
465 static struct platform_driver qcom_cpufreq_hw_driver = {
466 	.probe = qcom_cpufreq_hw_driver_probe,
467 	.remove = qcom_cpufreq_hw_driver_remove,
468 	.driver = {
469 		.name = "qcom-cpufreq-hw",
470 		.of_match_table = qcom_cpufreq_hw_match,
471 	},
472 };
473 
474 static int __init qcom_cpufreq_hw_init(void)
475 {
476 	return platform_driver_register(&qcom_cpufreq_hw_driver);
477 }
478 postcore_initcall(qcom_cpufreq_hw_init);
479 
480 static void __exit qcom_cpufreq_hw_exit(void)
481 {
482 	platform_driver_unregister(&qcom_cpufreq_hw_driver);
483 }
484 module_exit(qcom_cpufreq_hw_exit);
485 
486 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
487 MODULE_LICENSE("GPL v2");
488