1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * db8500_thermal.c - DB8500 Thermal Management Implementation
4  *
5  * Copyright (C) 2012 ST-Ericsson
6  * Copyright (C) 2012 Linaro Ltd.
7  *
8  * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
9  */
10 
11 #include <linux/cpu_cooling.h>
12 #include <linux/interrupt.h>
13 #include <linux/mfd/dbx500-prcmu.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_data/db8500_thermal.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include <linux/thermal.h>
20 
21 #define PRCMU_DEFAULT_MEASURE_TIME	0xFFF
22 #define PRCMU_DEFAULT_LOW_TEMP		0
23 
24 struct db8500_thermal_zone {
25 	struct thermal_zone_device *therm_dev;
26 	struct mutex th_lock;
27 	struct work_struct therm_work;
28 	struct db8500_thsens_platform_data *trip_tab;
29 	enum thermal_device_mode mode;
30 	enum thermal_trend trend;
31 	unsigned long cur_temp_pseudo;
32 	unsigned int cur_index;
33 };
34 
35 /* Local function to check if thermal zone matches cooling devices */
36 static int db8500_thermal_match_cdev(struct thermal_cooling_device *cdev,
37 		struct db8500_trip_point *trip_point)
38 {
39 	int i;
40 
41 	if (!strlen(cdev->type))
42 		return -EINVAL;
43 
44 	for (i = 0; i < COOLING_DEV_MAX; i++) {
45 		if (!strcmp(trip_point->cdev_name[i], cdev->type))
46 			return 0;
47 	}
48 
49 	return -ENODEV;
50 }
51 
52 /* Callback to bind cooling device to thermal zone */
53 static int db8500_cdev_bind(struct thermal_zone_device *thermal,
54 		struct thermal_cooling_device *cdev)
55 {
56 	struct db8500_thermal_zone *pzone = thermal->devdata;
57 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
58 	unsigned long max_state, upper, lower;
59 	int i, ret = -EINVAL;
60 
61 	cdev->ops->get_max_state(cdev, &max_state);
62 
63 	for (i = 0; i < ptrips->num_trips; i++) {
64 		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
65 			continue;
66 
67 		upper = lower = i > max_state ? max_state : i;
68 
69 		ret = thermal_zone_bind_cooling_device(thermal, i, cdev,
70 			upper, lower, THERMAL_WEIGHT_DEFAULT);
71 
72 		dev_info(&cdev->device, "%s bind to %d: %d-%s\n", cdev->type,
73 			i, ret, ret ? "fail" : "succeed");
74 	}
75 
76 	return ret;
77 }
78 
79 /* Callback to unbind cooling device from thermal zone */
80 static int db8500_cdev_unbind(struct thermal_zone_device *thermal,
81 		struct thermal_cooling_device *cdev)
82 {
83 	struct db8500_thermal_zone *pzone = thermal->devdata;
84 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
85 	int i, ret = -EINVAL;
86 
87 	for (i = 0; i < ptrips->num_trips; i++) {
88 		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
89 			continue;
90 
91 		ret = thermal_zone_unbind_cooling_device(thermal, i, cdev);
92 
93 		dev_info(&cdev->device, "%s unbind from %d: %s\n", cdev->type,
94 			i, ret ? "fail" : "succeed");
95 	}
96 
97 	return ret;
98 }
99 
100 /* Callback to get current temperature */
101 static int db8500_sys_get_temp(struct thermal_zone_device *thermal, int *temp)
102 {
103 	struct db8500_thermal_zone *pzone = thermal->devdata;
104 
105 	/*
106 	 * TODO: There is no PRCMU interface to get temperature data currently,
107 	 * so a pseudo temperature is returned , it works for thermal framework
108 	 * and this will be fixed when the PRCMU interface is available.
109 	 */
110 	*temp = pzone->cur_temp_pseudo;
111 
112 	return 0;
113 }
114 
115 /* Callback to get temperature changing trend */
116 static int db8500_sys_get_trend(struct thermal_zone_device *thermal,
117 		int trip, enum thermal_trend *trend)
118 {
119 	struct db8500_thermal_zone *pzone = thermal->devdata;
120 
121 	*trend = pzone->trend;
122 
123 	return 0;
124 }
125 
126 /* Callback to get thermal zone mode */
127 static int db8500_sys_get_mode(struct thermal_zone_device *thermal,
128 		enum thermal_device_mode *mode)
129 {
130 	struct db8500_thermal_zone *pzone = thermal->devdata;
131 
132 	mutex_lock(&pzone->th_lock);
133 	*mode = pzone->mode;
134 	mutex_unlock(&pzone->th_lock);
135 
136 	return 0;
137 }
138 
139 /* Callback to set thermal zone mode */
140 static int db8500_sys_set_mode(struct thermal_zone_device *thermal,
141 		enum thermal_device_mode mode)
142 {
143 	struct db8500_thermal_zone *pzone = thermal->devdata;
144 
145 	mutex_lock(&pzone->th_lock);
146 
147 	pzone->mode = mode;
148 	if (mode == THERMAL_DEVICE_ENABLED)
149 		schedule_work(&pzone->therm_work);
150 
151 	mutex_unlock(&pzone->th_lock);
152 
153 	return 0;
154 }
155 
156 /* Callback to get trip point type */
157 static int db8500_sys_get_trip_type(struct thermal_zone_device *thermal,
158 		int trip, enum thermal_trip_type *type)
159 {
160 	struct db8500_thermal_zone *pzone = thermal->devdata;
161 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
162 
163 	if (trip >= ptrips->num_trips)
164 		return -EINVAL;
165 
166 	*type = ptrips->trip_points[trip].type;
167 
168 	return 0;
169 }
170 
171 /* Callback to get trip point temperature */
172 static int db8500_sys_get_trip_temp(struct thermal_zone_device *thermal,
173 		int trip, int *temp)
174 {
175 	struct db8500_thermal_zone *pzone = thermal->devdata;
176 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
177 
178 	if (trip >= ptrips->num_trips)
179 		return -EINVAL;
180 
181 	*temp = ptrips->trip_points[trip].temp;
182 
183 	return 0;
184 }
185 
186 /* Callback to get critical trip point temperature */
187 static int db8500_sys_get_crit_temp(struct thermal_zone_device *thermal,
188 		int *temp)
189 {
190 	struct db8500_thermal_zone *pzone = thermal->devdata;
191 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
192 	int i;
193 
194 	for (i = ptrips->num_trips - 1; i > 0; i--) {
195 		if (ptrips->trip_points[i].type == THERMAL_TRIP_CRITICAL) {
196 			*temp = ptrips->trip_points[i].temp;
197 			return 0;
198 		}
199 	}
200 
201 	return -EINVAL;
202 }
203 
204 static struct thermal_zone_device_ops thdev_ops = {
205 	.bind = db8500_cdev_bind,
206 	.unbind = db8500_cdev_unbind,
207 	.get_temp = db8500_sys_get_temp,
208 	.get_trend = db8500_sys_get_trend,
209 	.get_mode = db8500_sys_get_mode,
210 	.set_mode = db8500_sys_set_mode,
211 	.get_trip_type = db8500_sys_get_trip_type,
212 	.get_trip_temp = db8500_sys_get_trip_temp,
213 	.get_crit_temp = db8500_sys_get_crit_temp,
214 };
215 
216 static void db8500_thermal_update_config(struct db8500_thermal_zone *pzone,
217 		unsigned int idx, enum thermal_trend trend,
218 		unsigned long next_low, unsigned long next_high)
219 {
220 	prcmu_stop_temp_sense();
221 
222 	pzone->cur_index = idx;
223 	pzone->cur_temp_pseudo = (next_low + next_high)/2;
224 	pzone->trend = trend;
225 
226 	prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
227 	prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
228 }
229 
230 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
231 {
232 	struct db8500_thermal_zone *pzone = irq_data;
233 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
234 	unsigned int idx = pzone->cur_index;
235 	unsigned long next_low, next_high;
236 
237 	if (unlikely(idx == 0))
238 		/* Meaningless for thermal management, ignoring it */
239 		return IRQ_HANDLED;
240 
241 	if (idx == 1) {
242 		next_high = ptrips->trip_points[0].temp;
243 		next_low = PRCMU_DEFAULT_LOW_TEMP;
244 	} else {
245 		next_high = ptrips->trip_points[idx-1].temp;
246 		next_low = ptrips->trip_points[idx-2].temp;
247 	}
248 	idx -= 1;
249 
250 	db8500_thermal_update_config(pzone, idx, THERMAL_TREND_DROPPING,
251 		next_low, next_high);
252 
253 	dev_dbg(&pzone->therm_dev->device,
254 		"PRCMU set max %ld, min %ld\n", next_high, next_low);
255 
256 	schedule_work(&pzone->therm_work);
257 
258 	return IRQ_HANDLED;
259 }
260 
261 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
262 {
263 	struct db8500_thermal_zone *pzone = irq_data;
264 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
265 	unsigned int idx = pzone->cur_index;
266 	unsigned long next_low, next_high;
267 
268 	if (idx < ptrips->num_trips - 1) {
269 		next_high = ptrips->trip_points[idx+1].temp;
270 		next_low = ptrips->trip_points[idx].temp;
271 		idx += 1;
272 
273 		db8500_thermal_update_config(pzone, idx, THERMAL_TREND_RAISING,
274 			next_low, next_high);
275 
276 		dev_dbg(&pzone->therm_dev->device,
277 		"PRCMU set max %ld, min %ld\n", next_high, next_low);
278 	} else if (idx == ptrips->num_trips - 1)
279 		pzone->cur_temp_pseudo = ptrips->trip_points[idx].temp + 1;
280 
281 	schedule_work(&pzone->therm_work);
282 
283 	return IRQ_HANDLED;
284 }
285 
286 static void db8500_thermal_work(struct work_struct *work)
287 {
288 	enum thermal_device_mode cur_mode;
289 	struct db8500_thermal_zone *pzone;
290 
291 	pzone = container_of(work, struct db8500_thermal_zone, therm_work);
292 
293 	mutex_lock(&pzone->th_lock);
294 	cur_mode = pzone->mode;
295 	mutex_unlock(&pzone->th_lock);
296 
297 	if (cur_mode == THERMAL_DEVICE_DISABLED)
298 		return;
299 
300 	thermal_zone_device_update(pzone->therm_dev, THERMAL_EVENT_UNSPECIFIED);
301 	dev_dbg(&pzone->therm_dev->device, "thermal work finished.\n");
302 }
303 
304 #ifdef CONFIG_OF
305 static struct db8500_thsens_platform_data*
306 		db8500_thermal_parse_dt(struct platform_device *pdev)
307 {
308 	struct db8500_thsens_platform_data *ptrips;
309 	struct device_node *np = pdev->dev.of_node;
310 	char prop_name[32];
311 	const char *tmp_str;
312 	u32 tmp_data;
313 	int i, j;
314 
315 	ptrips = devm_kzalloc(&pdev->dev, sizeof(*ptrips), GFP_KERNEL);
316 	if (!ptrips)
317 		return NULL;
318 
319 	if (of_property_read_u32(np, "num-trips", &tmp_data))
320 		goto err_parse_dt;
321 
322 	if (tmp_data > THERMAL_MAX_TRIPS)
323 		goto err_parse_dt;
324 
325 	ptrips->num_trips = tmp_data;
326 
327 	for (i = 0; i < ptrips->num_trips; i++) {
328 		sprintf(prop_name, "trip%d-temp", i);
329 		if (of_property_read_u32(np, prop_name, &tmp_data))
330 			goto err_parse_dt;
331 
332 		ptrips->trip_points[i].temp = tmp_data;
333 
334 		sprintf(prop_name, "trip%d-type", i);
335 		if (of_property_read_string(np, prop_name, &tmp_str))
336 			goto err_parse_dt;
337 
338 		if (!strcmp(tmp_str, "active"))
339 			ptrips->trip_points[i].type = THERMAL_TRIP_ACTIVE;
340 		else if (!strcmp(tmp_str, "passive"))
341 			ptrips->trip_points[i].type = THERMAL_TRIP_PASSIVE;
342 		else if (!strcmp(tmp_str, "hot"))
343 			ptrips->trip_points[i].type = THERMAL_TRIP_HOT;
344 		else if (!strcmp(tmp_str, "critical"))
345 			ptrips->trip_points[i].type = THERMAL_TRIP_CRITICAL;
346 		else
347 			goto err_parse_dt;
348 
349 		sprintf(prop_name, "trip%d-cdev-num", i);
350 		if (of_property_read_u32(np, prop_name, &tmp_data))
351 			goto err_parse_dt;
352 
353 		if (tmp_data > COOLING_DEV_MAX)
354 			goto err_parse_dt;
355 
356 		for (j = 0; j < tmp_data; j++) {
357 			sprintf(prop_name, "trip%d-cdev-name%d", i, j);
358 			if (of_property_read_string(np, prop_name, &tmp_str))
359 				goto err_parse_dt;
360 
361 			if (strlen(tmp_str) >= THERMAL_NAME_LENGTH)
362 				goto err_parse_dt;
363 
364 			strcpy(ptrips->trip_points[i].cdev_name[j], tmp_str);
365 		}
366 	}
367 	return ptrips;
368 
369 err_parse_dt:
370 	dev_err(&pdev->dev, "Parsing device tree data error.\n");
371 	return NULL;
372 }
373 #else
374 static inline struct db8500_thsens_platform_data*
375 		db8500_thermal_parse_dt(struct platform_device *pdev)
376 {
377 	return NULL;
378 }
379 #endif
380 
381 static int db8500_thermal_probe(struct platform_device *pdev)
382 {
383 	struct db8500_thermal_zone *pzone = NULL;
384 	struct db8500_thsens_platform_data *ptrips = NULL;
385 	struct device_node *np = pdev->dev.of_node;
386 	int low_irq, high_irq, ret = 0;
387 	unsigned long dft_low, dft_high;
388 
389 	if (np)
390 		ptrips = db8500_thermal_parse_dt(pdev);
391 	else
392 		ptrips = dev_get_platdata(&pdev->dev);
393 
394 	if (!ptrips)
395 		return -EINVAL;
396 
397 	pzone = devm_kzalloc(&pdev->dev, sizeof(*pzone), GFP_KERNEL);
398 	if (!pzone)
399 		return -ENOMEM;
400 
401 	mutex_init(&pzone->th_lock);
402 	mutex_lock(&pzone->th_lock);
403 
404 	pzone->mode = THERMAL_DEVICE_DISABLED;
405 	pzone->trip_tab = ptrips;
406 
407 	INIT_WORK(&pzone->therm_work, db8500_thermal_work);
408 
409 	low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
410 	if (low_irq < 0) {
411 		dev_err(&pdev->dev, "Get IRQ_HOTMON_LOW failed.\n");
412 		ret = low_irq;
413 		goto out_unlock;
414 	}
415 
416 	ret = devm_request_threaded_irq(&pdev->dev, low_irq, NULL,
417 		prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
418 		"dbx500_temp_low", pzone);
419 	if (ret < 0) {
420 		dev_err(&pdev->dev, "Failed to allocate temp low irq.\n");
421 		goto out_unlock;
422 	}
423 
424 	high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
425 	if (high_irq < 0) {
426 		dev_err(&pdev->dev, "Get IRQ_HOTMON_HIGH failed.\n");
427 		ret = high_irq;
428 		goto out_unlock;
429 	}
430 
431 	ret = devm_request_threaded_irq(&pdev->dev, high_irq, NULL,
432 		prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
433 		"dbx500_temp_high", pzone);
434 	if (ret < 0) {
435 		dev_err(&pdev->dev, "Failed to allocate temp high irq.\n");
436 		goto out_unlock;
437 	}
438 
439 	pzone->therm_dev = thermal_zone_device_register("db8500_thermal_zone",
440 		ptrips->num_trips, 0, pzone, &thdev_ops, NULL, 0, 0);
441 
442 	if (IS_ERR(pzone->therm_dev)) {
443 		dev_err(&pdev->dev, "Register thermal zone device failed.\n");
444 		ret = PTR_ERR(pzone->therm_dev);
445 		goto out_unlock;
446 	}
447 	dev_info(&pdev->dev, "Thermal zone device registered.\n");
448 
449 	dft_low = PRCMU_DEFAULT_LOW_TEMP;
450 	dft_high = ptrips->trip_points[0].temp;
451 
452 	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
453 		dft_low, dft_high);
454 
455 	platform_set_drvdata(pdev, pzone);
456 	pzone->mode = THERMAL_DEVICE_ENABLED;
457 
458 out_unlock:
459 	mutex_unlock(&pzone->th_lock);
460 
461 	return ret;
462 }
463 
464 static int db8500_thermal_remove(struct platform_device *pdev)
465 {
466 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
467 
468 	thermal_zone_device_unregister(pzone->therm_dev);
469 	cancel_work_sync(&pzone->therm_work);
470 	mutex_destroy(&pzone->th_lock);
471 
472 	return 0;
473 }
474 
475 static int db8500_thermal_suspend(struct platform_device *pdev,
476 		pm_message_t state)
477 {
478 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
479 
480 	flush_work(&pzone->therm_work);
481 	prcmu_stop_temp_sense();
482 
483 	return 0;
484 }
485 
486 static int db8500_thermal_resume(struct platform_device *pdev)
487 {
488 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
489 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
490 	unsigned long dft_low, dft_high;
491 
492 	dft_low = PRCMU_DEFAULT_LOW_TEMP;
493 	dft_high = ptrips->trip_points[0].temp;
494 
495 	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
496 		dft_low, dft_high);
497 
498 	return 0;
499 }
500 
501 #ifdef CONFIG_OF
502 static const struct of_device_id db8500_thermal_match[] = {
503 	{ .compatible = "stericsson,db8500-thermal" },
504 	{},
505 };
506 MODULE_DEVICE_TABLE(of, db8500_thermal_match);
507 #endif
508 
509 static struct platform_driver db8500_thermal_driver = {
510 	.driver = {
511 		.name = "db8500-thermal",
512 		.of_match_table = of_match_ptr(db8500_thermal_match),
513 	},
514 	.probe = db8500_thermal_probe,
515 	.suspend = db8500_thermal_suspend,
516 	.resume = db8500_thermal_resume,
517 	.remove = db8500_thermal_remove,
518 };
519 
520 module_platform_driver(db8500_thermal_driver);
521 
522 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
523 MODULE_DESCRIPTION("DB8500 thermal driver");
524 MODULE_LICENSE("GPL");
525