xref: /linux/drivers/thermal/db8500_thermal.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * db8500_thermal.c - DB8500 Thermal Management Implementation
3  *
4  * Copyright (C) 2012 ST-Ericsson
5  * Copyright (C) 2012 Linaro Ltd.
6  *
7  * Author: Hongbo Zhang <hongbo.zhang@linaro.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <linux/cpu_cooling.h>
21 #include <linux/interrupt.h>
22 #include <linux/mfd/dbx500-prcmu.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/platform_data/db8500_thermal.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/thermal.h>
29 
30 #define PRCMU_DEFAULT_MEASURE_TIME	0xFFF
31 #define PRCMU_DEFAULT_LOW_TEMP		0
32 
33 struct db8500_thermal_zone {
34 	struct thermal_zone_device *therm_dev;
35 	struct mutex th_lock;
36 	struct work_struct therm_work;
37 	struct db8500_thsens_platform_data *trip_tab;
38 	enum thermal_device_mode mode;
39 	enum thermal_trend trend;
40 	unsigned long cur_temp_pseudo;
41 	unsigned int cur_index;
42 };
43 
44 /* Local function to check if thermal zone matches cooling devices */
45 static int db8500_thermal_match_cdev(struct thermal_cooling_device *cdev,
46 		struct db8500_trip_point *trip_point)
47 {
48 	int i;
49 
50 	if (!strlen(cdev->type))
51 		return -EINVAL;
52 
53 	for (i = 0; i < COOLING_DEV_MAX; i++) {
54 		if (!strcmp(trip_point->cdev_name[i], cdev->type))
55 			return 0;
56 	}
57 
58 	return -ENODEV;
59 }
60 
61 /* Callback to bind cooling device to thermal zone */
62 static int db8500_cdev_bind(struct thermal_zone_device *thermal,
63 		struct thermal_cooling_device *cdev)
64 {
65 	struct db8500_thermal_zone *pzone = thermal->devdata;
66 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
67 	unsigned long max_state, upper, lower;
68 	int i, ret = -EINVAL;
69 
70 	cdev->ops->get_max_state(cdev, &max_state);
71 
72 	for (i = 0; i < ptrips->num_trips; i++) {
73 		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
74 			continue;
75 
76 		upper = lower = i > max_state ? max_state : i;
77 
78 		ret = thermal_zone_bind_cooling_device(thermal, i, cdev,
79 			upper, lower);
80 
81 		dev_info(&cdev->device, "%s bind to %d: %d-%s\n", cdev->type,
82 			i, ret, ret ? "fail" : "succeed");
83 	}
84 
85 	return ret;
86 }
87 
88 /* Callback to unbind cooling device from thermal zone */
89 static int db8500_cdev_unbind(struct thermal_zone_device *thermal,
90 		struct thermal_cooling_device *cdev)
91 {
92 	struct db8500_thermal_zone *pzone = thermal->devdata;
93 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
94 	int i, ret = -EINVAL;
95 
96 	for (i = 0; i < ptrips->num_trips; i++) {
97 		if (db8500_thermal_match_cdev(cdev, &ptrips->trip_points[i]))
98 			continue;
99 
100 		ret = thermal_zone_unbind_cooling_device(thermal, i, cdev);
101 
102 		dev_info(&cdev->device, "%s unbind from %d: %s\n", cdev->type,
103 			i, ret ? "fail" : "succeed");
104 	}
105 
106 	return ret;
107 }
108 
109 /* Callback to get current temperature */
110 static int db8500_sys_get_temp(struct thermal_zone_device *thermal,
111 		unsigned long *temp)
112 {
113 	struct db8500_thermal_zone *pzone = thermal->devdata;
114 
115 	/*
116 	 * TODO: There is no PRCMU interface to get temperature data currently,
117 	 * so a pseudo temperature is returned , it works for thermal framework
118 	 * and this will be fixed when the PRCMU interface is available.
119 	 */
120 	*temp = pzone->cur_temp_pseudo;
121 
122 	return 0;
123 }
124 
125 /* Callback to get temperature changing trend */
126 static int db8500_sys_get_trend(struct thermal_zone_device *thermal,
127 		int trip, enum thermal_trend *trend)
128 {
129 	struct db8500_thermal_zone *pzone = thermal->devdata;
130 
131 	*trend = pzone->trend;
132 
133 	return 0;
134 }
135 
136 /* Callback to get thermal zone mode */
137 static int db8500_sys_get_mode(struct thermal_zone_device *thermal,
138 		enum thermal_device_mode *mode)
139 {
140 	struct db8500_thermal_zone *pzone = thermal->devdata;
141 
142 	mutex_lock(&pzone->th_lock);
143 	*mode = pzone->mode;
144 	mutex_unlock(&pzone->th_lock);
145 
146 	return 0;
147 }
148 
149 /* Callback to set thermal zone mode */
150 static int db8500_sys_set_mode(struct thermal_zone_device *thermal,
151 		enum thermal_device_mode mode)
152 {
153 	struct db8500_thermal_zone *pzone = thermal->devdata;
154 
155 	mutex_lock(&pzone->th_lock);
156 
157 	pzone->mode = mode;
158 	if (mode == THERMAL_DEVICE_ENABLED)
159 		schedule_work(&pzone->therm_work);
160 
161 	mutex_unlock(&pzone->th_lock);
162 
163 	return 0;
164 }
165 
166 /* Callback to get trip point type */
167 static int db8500_sys_get_trip_type(struct thermal_zone_device *thermal,
168 		int trip, enum thermal_trip_type *type)
169 {
170 	struct db8500_thermal_zone *pzone = thermal->devdata;
171 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
172 
173 	if (trip >= ptrips->num_trips)
174 		return -EINVAL;
175 
176 	*type = ptrips->trip_points[trip].type;
177 
178 	return 0;
179 }
180 
181 /* Callback to get trip point temperature */
182 static int db8500_sys_get_trip_temp(struct thermal_zone_device *thermal,
183 		int trip, unsigned long *temp)
184 {
185 	struct db8500_thermal_zone *pzone = thermal->devdata;
186 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
187 
188 	if (trip >= ptrips->num_trips)
189 		return -EINVAL;
190 
191 	*temp = ptrips->trip_points[trip].temp;
192 
193 	return 0;
194 }
195 
196 /* Callback to get critical trip point temperature */
197 static int db8500_sys_get_crit_temp(struct thermal_zone_device *thermal,
198 		unsigned long *temp)
199 {
200 	struct db8500_thermal_zone *pzone = thermal->devdata;
201 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
202 	int i;
203 
204 	for (i = ptrips->num_trips - 1; i > 0; i--) {
205 		if (ptrips->trip_points[i].type == THERMAL_TRIP_CRITICAL) {
206 			*temp = ptrips->trip_points[i].temp;
207 			return 0;
208 		}
209 	}
210 
211 	return -EINVAL;
212 }
213 
214 static struct thermal_zone_device_ops thdev_ops = {
215 	.bind = db8500_cdev_bind,
216 	.unbind = db8500_cdev_unbind,
217 	.get_temp = db8500_sys_get_temp,
218 	.get_trend = db8500_sys_get_trend,
219 	.get_mode = db8500_sys_get_mode,
220 	.set_mode = db8500_sys_set_mode,
221 	.get_trip_type = db8500_sys_get_trip_type,
222 	.get_trip_temp = db8500_sys_get_trip_temp,
223 	.get_crit_temp = db8500_sys_get_crit_temp,
224 };
225 
226 static void db8500_thermal_update_config(struct db8500_thermal_zone *pzone,
227 		unsigned int idx, enum thermal_trend trend,
228 		unsigned long next_low, unsigned long next_high)
229 {
230 	prcmu_stop_temp_sense();
231 
232 	pzone->cur_index = idx;
233 	pzone->cur_temp_pseudo = (next_low + next_high)/2;
234 	pzone->trend = trend;
235 
236 	prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
237 	prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
238 }
239 
240 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
241 {
242 	struct db8500_thermal_zone *pzone = irq_data;
243 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
244 	unsigned int idx = pzone->cur_index;
245 	unsigned long next_low, next_high;
246 
247 	if (unlikely(idx == 0))
248 		/* Meaningless for thermal management, ignoring it */
249 		return IRQ_HANDLED;
250 
251 	if (idx == 1) {
252 		next_high = ptrips->trip_points[0].temp;
253 		next_low = PRCMU_DEFAULT_LOW_TEMP;
254 	} else {
255 		next_high = ptrips->trip_points[idx-1].temp;
256 		next_low = ptrips->trip_points[idx-2].temp;
257 	}
258 	idx -= 1;
259 
260 	db8500_thermal_update_config(pzone, idx, THERMAL_TREND_DROPPING,
261 		next_low, next_high);
262 
263 	dev_dbg(&pzone->therm_dev->device,
264 		"PRCMU set max %ld, min %ld\n", next_high, next_low);
265 
266 	schedule_work(&pzone->therm_work);
267 
268 	return IRQ_HANDLED;
269 }
270 
271 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
272 {
273 	struct db8500_thermal_zone *pzone = irq_data;
274 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
275 	unsigned int idx = pzone->cur_index;
276 	unsigned long next_low, next_high;
277 
278 	if (idx < ptrips->num_trips - 1) {
279 		next_high = ptrips->trip_points[idx+1].temp;
280 		next_low = ptrips->trip_points[idx].temp;
281 		idx += 1;
282 
283 		db8500_thermal_update_config(pzone, idx, THERMAL_TREND_RAISING,
284 			next_low, next_high);
285 
286 		dev_dbg(&pzone->therm_dev->device,
287 		"PRCMU set max %ld, min %ld\n", next_high, next_low);
288 	} else if (idx == ptrips->num_trips - 1)
289 		pzone->cur_temp_pseudo = ptrips->trip_points[idx].temp + 1;
290 
291 	schedule_work(&pzone->therm_work);
292 
293 	return IRQ_HANDLED;
294 }
295 
296 static void db8500_thermal_work(struct work_struct *work)
297 {
298 	enum thermal_device_mode cur_mode;
299 	struct db8500_thermal_zone *pzone;
300 
301 	pzone = container_of(work, struct db8500_thermal_zone, therm_work);
302 
303 	mutex_lock(&pzone->th_lock);
304 	cur_mode = pzone->mode;
305 	mutex_unlock(&pzone->th_lock);
306 
307 	if (cur_mode == THERMAL_DEVICE_DISABLED)
308 		return;
309 
310 	thermal_zone_device_update(pzone->therm_dev);
311 	dev_dbg(&pzone->therm_dev->device, "thermal work finished.\n");
312 }
313 
314 #ifdef CONFIG_OF
315 static struct db8500_thsens_platform_data*
316 		db8500_thermal_parse_dt(struct platform_device *pdev)
317 {
318 	struct db8500_thsens_platform_data *ptrips;
319 	struct device_node *np = pdev->dev.of_node;
320 	char prop_name[32];
321 	const char *tmp_str;
322 	u32 tmp_data;
323 	int i, j;
324 
325 	ptrips = devm_kzalloc(&pdev->dev, sizeof(*ptrips), GFP_KERNEL);
326 	if (!ptrips)
327 		return NULL;
328 
329 	if (of_property_read_u32(np, "num-trips", &tmp_data))
330 		goto err_parse_dt;
331 
332 	if (tmp_data > THERMAL_MAX_TRIPS)
333 		goto err_parse_dt;
334 
335 	ptrips->num_trips = tmp_data;
336 
337 	for (i = 0; i < ptrips->num_trips; i++) {
338 		sprintf(prop_name, "trip%d-temp", i);
339 		if (of_property_read_u32(np, prop_name, &tmp_data))
340 			goto err_parse_dt;
341 
342 		ptrips->trip_points[i].temp = tmp_data;
343 
344 		sprintf(prop_name, "trip%d-type", i);
345 		if (of_property_read_string(np, prop_name, &tmp_str))
346 			goto err_parse_dt;
347 
348 		if (!strcmp(tmp_str, "active"))
349 			ptrips->trip_points[i].type = THERMAL_TRIP_ACTIVE;
350 		else if (!strcmp(tmp_str, "passive"))
351 			ptrips->trip_points[i].type = THERMAL_TRIP_PASSIVE;
352 		else if (!strcmp(tmp_str, "hot"))
353 			ptrips->trip_points[i].type = THERMAL_TRIP_HOT;
354 		else if (!strcmp(tmp_str, "critical"))
355 			ptrips->trip_points[i].type = THERMAL_TRIP_CRITICAL;
356 		else
357 			goto err_parse_dt;
358 
359 		sprintf(prop_name, "trip%d-cdev-num", i);
360 		if (of_property_read_u32(np, prop_name, &tmp_data))
361 			goto err_parse_dt;
362 
363 		if (tmp_data > COOLING_DEV_MAX)
364 			goto err_parse_dt;
365 
366 		for (j = 0; j < tmp_data; j++) {
367 			sprintf(prop_name, "trip%d-cdev-name%d", i, j);
368 			if (of_property_read_string(np, prop_name, &tmp_str))
369 				goto err_parse_dt;
370 
371 			if (strlen(tmp_str) >= THERMAL_NAME_LENGTH)
372 				goto err_parse_dt;
373 
374 			strcpy(ptrips->trip_points[i].cdev_name[j], tmp_str);
375 		}
376 	}
377 	return ptrips;
378 
379 err_parse_dt:
380 	dev_err(&pdev->dev, "Parsing device tree data error.\n");
381 	return NULL;
382 }
383 #else
384 static inline struct db8500_thsens_platform_data*
385 		db8500_thermal_parse_dt(struct platform_device *pdev)
386 {
387 	return NULL;
388 }
389 #endif
390 
391 static int db8500_thermal_probe(struct platform_device *pdev)
392 {
393 	struct db8500_thermal_zone *pzone = NULL;
394 	struct db8500_thsens_platform_data *ptrips = NULL;
395 	struct device_node *np = pdev->dev.of_node;
396 	int low_irq, high_irq, ret = 0;
397 	unsigned long dft_low, dft_high;
398 
399 	if (np)
400 		ptrips = db8500_thermal_parse_dt(pdev);
401 	else
402 		ptrips = dev_get_platdata(&pdev->dev);
403 
404 	if (!ptrips)
405 		return -EINVAL;
406 
407 	pzone = devm_kzalloc(&pdev->dev, sizeof(*pzone), GFP_KERNEL);
408 	if (!pzone)
409 		return -ENOMEM;
410 
411 	mutex_init(&pzone->th_lock);
412 	mutex_lock(&pzone->th_lock);
413 
414 	pzone->mode = THERMAL_DEVICE_DISABLED;
415 	pzone->trip_tab = ptrips;
416 
417 	INIT_WORK(&pzone->therm_work, db8500_thermal_work);
418 
419 	low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
420 	if (low_irq < 0) {
421 		dev_err(&pdev->dev, "Get IRQ_HOTMON_LOW failed.\n");
422 		ret = low_irq;
423 		goto out_unlock;
424 	}
425 
426 	ret = devm_request_threaded_irq(&pdev->dev, low_irq, NULL,
427 		prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
428 		"dbx500_temp_low", pzone);
429 	if (ret < 0) {
430 		dev_err(&pdev->dev, "Failed to allocate temp low irq.\n");
431 		goto out_unlock;
432 	}
433 
434 	high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
435 	if (high_irq < 0) {
436 		dev_err(&pdev->dev, "Get IRQ_HOTMON_HIGH failed.\n");
437 		ret = high_irq;
438 		goto out_unlock;
439 	}
440 
441 	ret = devm_request_threaded_irq(&pdev->dev, high_irq, NULL,
442 		prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
443 		"dbx500_temp_high", pzone);
444 	if (ret < 0) {
445 		dev_err(&pdev->dev, "Failed to allocate temp high irq.\n");
446 		goto out_unlock;
447 	}
448 
449 	pzone->therm_dev = thermal_zone_device_register("db8500_thermal_zone",
450 		ptrips->num_trips, 0, pzone, &thdev_ops, NULL, 0, 0);
451 
452 	if (IS_ERR(pzone->therm_dev)) {
453 		dev_err(&pdev->dev, "Register thermal zone device failed.\n");
454 		ret = PTR_ERR(pzone->therm_dev);
455 		goto out_unlock;
456 	}
457 	dev_info(&pdev->dev, "Thermal zone device registered.\n");
458 
459 	dft_low = PRCMU_DEFAULT_LOW_TEMP;
460 	dft_high = ptrips->trip_points[0].temp;
461 
462 	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
463 		dft_low, dft_high);
464 
465 	platform_set_drvdata(pdev, pzone);
466 	pzone->mode = THERMAL_DEVICE_ENABLED;
467 
468 out_unlock:
469 	mutex_unlock(&pzone->th_lock);
470 
471 	return ret;
472 }
473 
474 static int db8500_thermal_remove(struct platform_device *pdev)
475 {
476 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
477 
478 	thermal_zone_device_unregister(pzone->therm_dev);
479 	cancel_work_sync(&pzone->therm_work);
480 	mutex_destroy(&pzone->th_lock);
481 
482 	return 0;
483 }
484 
485 static int db8500_thermal_suspend(struct platform_device *pdev,
486 		pm_message_t state)
487 {
488 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
489 
490 	flush_work(&pzone->therm_work);
491 	prcmu_stop_temp_sense();
492 
493 	return 0;
494 }
495 
496 static int db8500_thermal_resume(struct platform_device *pdev)
497 {
498 	struct db8500_thermal_zone *pzone = platform_get_drvdata(pdev);
499 	struct db8500_thsens_platform_data *ptrips = pzone->trip_tab;
500 	unsigned long dft_low, dft_high;
501 
502 	dft_low = PRCMU_DEFAULT_LOW_TEMP;
503 	dft_high = ptrips->trip_points[0].temp;
504 
505 	db8500_thermal_update_config(pzone, 0, THERMAL_TREND_STABLE,
506 		dft_low, dft_high);
507 
508 	return 0;
509 }
510 
511 #ifdef CONFIG_OF
512 static const struct of_device_id db8500_thermal_match[] = {
513 	{ .compatible = "stericsson,db8500-thermal" },
514 	{},
515 };
516 #endif
517 
518 static struct platform_driver db8500_thermal_driver = {
519 	.driver = {
520 		.owner = THIS_MODULE,
521 		.name = "db8500-thermal",
522 		.of_match_table = of_match_ptr(db8500_thermal_match),
523 	},
524 	.probe = db8500_thermal_probe,
525 	.suspend = db8500_thermal_suspend,
526 	.resume = db8500_thermal_resume,
527 	.remove = db8500_thermal_remove,
528 };
529 
530 module_platform_driver(db8500_thermal_driver);
531 
532 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
533 MODULE_DESCRIPTION("DB8500 thermal driver");
534 MODULE_LICENSE("GPL");
535