1 /*
2  * OMAP thermal driver interface
3  *
4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
5  * Contact:
6  *   Eduardo Valentin <eduardo.valentin@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA
21  *
22  */
23 
24 #include <linux/device.h>
25 #include <linux/err.h>
26 #include <linux/mutex.h>
27 #include <linux/gfp.h>
28 #include <linux/kernel.h>
29 #include <linux/workqueue.h>
30 #include <linux/thermal.h>
31 #include <linux/cpumask.h>
32 #include <linux/cpu_cooling.h>
33 #include <linux/of.h>
34 
35 #include "ti-thermal.h"
36 #include "ti-bandgap.h"
37 
38 /* common data structures */
39 struct ti_thermal_data {
40 	struct thermal_zone_device *ti_thermal;
41 	struct thermal_zone_device *pcb_tz;
42 	struct thermal_cooling_device *cool_dev;
43 	struct ti_bandgap *bgp;
44 	enum thermal_device_mode mode;
45 	struct work_struct thermal_wq;
46 	int sensor_id;
47 	bool our_zone;
48 };
49 
50 static void ti_thermal_work(struct work_struct *work)
51 {
52 	struct ti_thermal_data *data = container_of(work,
53 					struct ti_thermal_data, thermal_wq);
54 
55 	thermal_zone_device_update(data->ti_thermal);
56 
57 	dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
58 		data->ti_thermal->type);
59 }
60 
61 /**
62  * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
63  * @t:	omap sensor temperature
64  * @s:	omap sensor slope value
65  * @c:	omap sensor const value
66  */
67 static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
68 {
69 	int delta = t * s / 1000 + c;
70 
71 	if (delta < 0)
72 		delta = 0;
73 
74 	return t + delta;
75 }
76 
77 /* thermal zone ops */
78 /* Get temperature callback function for thermal zone*/
79 static inline int __ti_thermal_get_temp(void *devdata, long *temp)
80 {
81 	struct thermal_zone_device *pcb_tz = NULL;
82 	struct ti_thermal_data *data = devdata;
83 	struct ti_bandgap *bgp;
84 	const struct ti_temp_sensor *s;
85 	int ret, tmp, slope, constant;
86 	unsigned long pcb_temp;
87 
88 	if (!data)
89 		return 0;
90 
91 	bgp = data->bgp;
92 	s = &bgp->conf->sensors[data->sensor_id];
93 
94 	ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
95 	if (ret)
96 		return ret;
97 
98 	/* Default constants */
99 	slope = s->slope;
100 	constant = s->constant;
101 
102 	pcb_tz = data->pcb_tz;
103 	/* In case pcb zone is available, use the extrapolation rule with it */
104 	if (!IS_ERR(pcb_tz)) {
105 		ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
106 		if (!ret) {
107 			tmp -= pcb_temp; /* got a valid PCB temp */
108 			slope = s->slope_pcb;
109 			constant = s->constant_pcb;
110 		} else {
111 			dev_err(bgp->dev,
112 				"Failed to read PCB state. Using defaults\n");
113 			ret = 0;
114 		}
115 	}
116 	*temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
117 
118 	return ret;
119 }
120 
121 static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
122 				      unsigned long *temp)
123 {
124 	struct ti_thermal_data *data = thermal->devdata;
125 
126 	return __ti_thermal_get_temp(data, temp);
127 }
128 
129 /* Bind callback functions for thermal zone */
130 static int ti_thermal_bind(struct thermal_zone_device *thermal,
131 			   struct thermal_cooling_device *cdev)
132 {
133 	struct ti_thermal_data *data = thermal->devdata;
134 	int id;
135 
136 	if (!data || IS_ERR(data))
137 		return -ENODEV;
138 
139 	/* check if this is the cooling device we registered */
140 	if (data->cool_dev != cdev)
141 		return 0;
142 
143 	id = data->sensor_id;
144 
145 	/* Simple thing, two trips, one passive another critical */
146 	return thermal_zone_bind_cooling_device(thermal, 0, cdev,
147 	/* bind with min and max states defined by cpu_cooling */
148 						THERMAL_NO_LIMIT,
149 						THERMAL_NO_LIMIT);
150 }
151 
152 /* Unbind callback functions for thermal zone */
153 static int ti_thermal_unbind(struct thermal_zone_device *thermal,
154 			     struct thermal_cooling_device *cdev)
155 {
156 	struct ti_thermal_data *data = thermal->devdata;
157 
158 	if (!data || IS_ERR(data))
159 		return -ENODEV;
160 
161 	/* check if this is the cooling device we registered */
162 	if (data->cool_dev != cdev)
163 		return 0;
164 
165 	/* Simple thing, two trips, one passive another critical */
166 	return thermal_zone_unbind_cooling_device(thermal, 0, cdev);
167 }
168 
169 /* Get mode callback functions for thermal zone */
170 static int ti_thermal_get_mode(struct thermal_zone_device *thermal,
171 			       enum thermal_device_mode *mode)
172 {
173 	struct ti_thermal_data *data = thermal->devdata;
174 
175 	if (data)
176 		*mode = data->mode;
177 
178 	return 0;
179 }
180 
181 /* Set mode callback functions for thermal zone */
182 static int ti_thermal_set_mode(struct thermal_zone_device *thermal,
183 			       enum thermal_device_mode mode)
184 {
185 	struct ti_thermal_data *data = thermal->devdata;
186 	struct ti_bandgap *bgp;
187 
188 	bgp = data->bgp;
189 
190 	if (!data->ti_thermal) {
191 		dev_notice(&thermal->device, "thermal zone not registered\n");
192 		return 0;
193 	}
194 
195 	mutex_lock(&data->ti_thermal->lock);
196 
197 	if (mode == THERMAL_DEVICE_ENABLED)
198 		data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
199 	else
200 		data->ti_thermal->polling_delay = 0;
201 
202 	mutex_unlock(&data->ti_thermal->lock);
203 
204 	data->mode = mode;
205 	ti_bandgap_write_update_interval(bgp, data->sensor_id,
206 					data->ti_thermal->polling_delay);
207 	thermal_zone_device_update(data->ti_thermal);
208 	dev_dbg(&thermal->device, "thermal polling set for duration=%d msec\n",
209 		data->ti_thermal->polling_delay);
210 
211 	return 0;
212 }
213 
214 /* Get trip type callback functions for thermal zone */
215 static int ti_thermal_get_trip_type(struct thermal_zone_device *thermal,
216 				    int trip, enum thermal_trip_type *type)
217 {
218 	if (!ti_thermal_is_valid_trip(trip))
219 		return -EINVAL;
220 
221 	if (trip + 1 == OMAP_TRIP_NUMBER)
222 		*type = THERMAL_TRIP_CRITICAL;
223 	else
224 		*type = THERMAL_TRIP_PASSIVE;
225 
226 	return 0;
227 }
228 
229 /* Get trip temperature callback functions for thermal zone */
230 static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
231 				    int trip, unsigned long *temp)
232 {
233 	if (!ti_thermal_is_valid_trip(trip))
234 		return -EINVAL;
235 
236 	*temp = ti_thermal_get_trip_value(trip);
237 
238 	return 0;
239 }
240 
241 static int __ti_thermal_get_trend(void *p, long *trend)
242 {
243 	struct ti_thermal_data *data = p;
244 	struct ti_bandgap *bgp;
245 	int id, tr, ret = 0;
246 
247 	bgp = data->bgp;
248 	id = data->sensor_id;
249 
250 	ret = ti_bandgap_get_trend(bgp, id, &tr);
251 	if (ret)
252 		return ret;
253 
254 	*trend = tr;
255 
256 	return 0;
257 }
258 
259 /* Get the temperature trend callback functions for thermal zone */
260 static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
261 				int trip, enum thermal_trend *trend)
262 {
263 	int ret;
264 	long tr;
265 
266 	ret = __ti_thermal_get_trend(thermal->devdata, &tr);
267 	if (ret)
268 		return ret;
269 
270 	if (tr > 0)
271 		*trend = THERMAL_TREND_RAISING;
272 	else if (tr < 0)
273 		*trend = THERMAL_TREND_DROPPING;
274 	else
275 		*trend = THERMAL_TREND_STABLE;
276 
277 	return 0;
278 }
279 
280 /* Get critical temperature callback functions for thermal zone */
281 static int ti_thermal_get_crit_temp(struct thermal_zone_device *thermal,
282 				    unsigned long *temp)
283 {
284 	/* shutdown zone */
285 	return ti_thermal_get_trip_temp(thermal, OMAP_TRIP_NUMBER - 1, temp);
286 }
287 
288 static const struct thermal_zone_of_device_ops ti_of_thermal_ops = {
289 	.get_temp = __ti_thermal_get_temp,
290 	.get_trend = __ti_thermal_get_trend,
291 };
292 
293 static struct thermal_zone_device_ops ti_thermal_ops = {
294 	.get_temp = ti_thermal_get_temp,
295 	.get_trend = ti_thermal_get_trend,
296 	.bind = ti_thermal_bind,
297 	.unbind = ti_thermal_unbind,
298 	.get_mode = ti_thermal_get_mode,
299 	.set_mode = ti_thermal_set_mode,
300 	.get_trip_type = ti_thermal_get_trip_type,
301 	.get_trip_temp = ti_thermal_get_trip_temp,
302 	.get_crit_temp = ti_thermal_get_crit_temp,
303 };
304 
305 static struct ti_thermal_data
306 *ti_thermal_build_data(struct ti_bandgap *bgp, int id)
307 {
308 	struct ti_thermal_data *data;
309 
310 	data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
311 	if (!data) {
312 		dev_err(bgp->dev, "kzalloc fail\n");
313 		return NULL;
314 	}
315 	data->sensor_id = id;
316 	data->bgp = bgp;
317 	data->mode = THERMAL_DEVICE_ENABLED;
318 	/* pcb_tz will be either valid or PTR_ERR() */
319 	data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
320 	INIT_WORK(&data->thermal_wq, ti_thermal_work);
321 
322 	return data;
323 }
324 
325 int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
326 			     char *domain)
327 {
328 	struct ti_thermal_data *data;
329 
330 	data = ti_bandgap_get_sensor_data(bgp, id);
331 
332 	if (!data || IS_ERR(data))
333 		data = ti_thermal_build_data(bgp, id);
334 
335 	if (!data)
336 		return -EINVAL;
337 
338 	/* in case this is specified by DT */
339 	data->ti_thermal = thermal_zone_of_sensor_register(bgp->dev, id,
340 					data, &ti_of_thermal_ops);
341 	if (IS_ERR(data->ti_thermal)) {
342 		/* Create thermal zone */
343 		data->ti_thermal = thermal_zone_device_register(domain,
344 				OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,
345 				NULL, FAST_TEMP_MONITORING_RATE,
346 				FAST_TEMP_MONITORING_RATE);
347 		if (IS_ERR(data->ti_thermal)) {
348 			dev_err(bgp->dev, "thermal zone device is NULL\n");
349 			return PTR_ERR(data->ti_thermal);
350 		}
351 		data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
352 		data->our_zone = true;
353 	}
354 	ti_bandgap_set_sensor_data(bgp, id, data);
355 	ti_bandgap_write_update_interval(bgp, data->sensor_id,
356 					data->ti_thermal->polling_delay);
357 
358 	return 0;
359 }
360 
361 int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
362 {
363 	struct ti_thermal_data *data;
364 
365 	data = ti_bandgap_get_sensor_data(bgp, id);
366 
367 	if (data && data->ti_thermal) {
368 		if (data->our_zone)
369 			thermal_zone_device_unregister(data->ti_thermal);
370 		else
371 			thermal_zone_of_sensor_unregister(bgp->dev,
372 							  data->ti_thermal);
373 	}
374 
375 	return 0;
376 }
377 
378 int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
379 {
380 	struct ti_thermal_data *data;
381 
382 	data = ti_bandgap_get_sensor_data(bgp, id);
383 
384 	schedule_work(&data->thermal_wq);
385 
386 	return 0;
387 }
388 
389 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
390 {
391 	struct ti_thermal_data *data;
392 	struct device_node *np = bgp->dev->of_node;
393 
394 	/*
395 	 * We are assuming here that if one deploys the zone
396 	 * using DT, then it must be aware that the cooling device
397 	 * loading has to happen via cpufreq driver.
398 	 */
399 	if (of_find_property(np, "#thermal-sensor-cells", NULL))
400 		return 0;
401 
402 	data = ti_bandgap_get_sensor_data(bgp, id);
403 	if (!data || IS_ERR(data))
404 		data = ti_thermal_build_data(bgp, id);
405 
406 	if (!data)
407 		return -EINVAL;
408 
409 	/* Register cooling device */
410 	data->cool_dev = cpufreq_cooling_register(cpu_present_mask);
411 	if (IS_ERR(data->cool_dev)) {
412 		int ret = PTR_ERR(data->cool_dev);
413 
414 		if (ret != -EPROBE_DEFER)
415 			dev_err(bgp->dev,
416 				"Failed to register cpu cooling device %d\n",
417 				ret);
418 
419 		return ret;
420 	}
421 	ti_bandgap_set_sensor_data(bgp, id, data);
422 
423 	return 0;
424 }
425 
426 int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
427 {
428 	struct ti_thermal_data *data;
429 
430 	data = ti_bandgap_get_sensor_data(bgp, id);
431 
432 	if (data && data->cool_dev)
433 		cpufreq_cooling_unregister(data->cool_dev);
434 
435 	return 0;
436 }
437