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
33struct 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 */
45static 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 */
62static 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 */
89static 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 */
110static 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 */
126static 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 */
137static 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 */
150static 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 */
167static 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 */
182static 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 */
197static 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
214static 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
226static 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
240static 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
271static 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
296static 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
315static 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
379err_parse_dt:
380	dev_err(&pdev->dev, "Parsing device tree data error.\n");
381	return NULL;
382}
383#else
384static inline struct db8500_thsens_platform_data*
385		db8500_thermal_parse_dt(struct platform_device *pdev)
386{
387	return NULL;
388}
389#endif
390
391static 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
468out_unlock:
469	mutex_unlock(&pzone->th_lock);
470
471	return ret;
472}
473
474static 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
485static 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
496static 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
512static const struct of_device_id db8500_thermal_match[] = {
513	{ .compatible = "stericsson,db8500-thermal" },
514	{},
515};
516#endif
517
518static struct platform_driver db8500_thermal_driver = {
519	.driver = {
520		.name = "db8500-thermal",
521		.of_match_table = of_match_ptr(db8500_thermal_match),
522	},
523	.probe = db8500_thermal_probe,
524	.suspend = db8500_thermal_suspend,
525	.resume = db8500_thermal_resume,
526	.remove = db8500_thermal_remove,
527};
528
529module_platform_driver(db8500_thermal_driver);
530
531MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
532MODULE_DESCRIPTION("DB8500 thermal driver");
533MODULE_LICENSE("GPL");
534