xref: /openbmc/linux/drivers/thermal/imx_thermal.c (revision 9cfc5c90)
1 /*
2  * Copyright 2013 Freescale Semiconductor, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/cpu_cooling.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24 #include <linux/slab.h>
25 #include <linux/thermal.h>
26 #include <linux/types.h>
27 
28 #define REG_SET		0x4
29 #define REG_CLR		0x8
30 #define REG_TOG		0xc
31 
32 #define MISC0				0x0150
33 #define MISC0_REFTOP_SELBIASOFF		(1 << 3)
34 #define MISC1				0x0160
35 #define MISC1_IRQ_TEMPHIGH		(1 << 29)
36 /* Below LOW and PANIC bits are only for TEMPMON_IMX6SX */
37 #define MISC1_IRQ_TEMPLOW		(1 << 28)
38 #define MISC1_IRQ_TEMPPANIC		(1 << 27)
39 
40 #define TEMPSENSE0			0x0180
41 #define TEMPSENSE0_ALARM_VALUE_SHIFT	20
42 #define TEMPSENSE0_ALARM_VALUE_MASK	(0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT)
43 #define TEMPSENSE0_TEMP_CNT_SHIFT	8
44 #define TEMPSENSE0_TEMP_CNT_MASK	(0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
45 #define TEMPSENSE0_FINISHED		(1 << 2)
46 #define TEMPSENSE0_MEASURE_TEMP		(1 << 1)
47 #define TEMPSENSE0_POWER_DOWN		(1 << 0)
48 
49 #define TEMPSENSE1			0x0190
50 #define TEMPSENSE1_MEASURE_FREQ		0xffff
51 /* Below TEMPSENSE2 is only for TEMPMON_IMX6SX */
52 #define TEMPSENSE2			0x0290
53 #define TEMPSENSE2_LOW_VALUE_SHIFT	0
54 #define TEMPSENSE2_LOW_VALUE_MASK	0xfff
55 #define TEMPSENSE2_PANIC_VALUE_SHIFT	16
56 #define TEMPSENSE2_PANIC_VALUE_MASK	0xfff0000
57 
58 #define OCOTP_ANA1			0x04e0
59 
60 /* The driver supports 1 passive trip point and 1 critical trip point */
61 enum imx_thermal_trip {
62 	IMX_TRIP_PASSIVE,
63 	IMX_TRIP_CRITICAL,
64 	IMX_TRIP_NUM,
65 };
66 
67 /*
68  * It defines the temperature in millicelsius for passive trip point
69  * that will trigger cooling action when crossed.
70  */
71 #define IMX_TEMP_PASSIVE		85000
72 
73 #define IMX_POLLING_DELAY		2000 /* millisecond */
74 #define IMX_PASSIVE_DELAY		1000
75 
76 #define FACTOR0				10000000
77 #define FACTOR1				15976
78 #define FACTOR2				4297157
79 
80 #define TEMPMON_IMX6Q			1
81 #define TEMPMON_IMX6SX			2
82 
83 struct thermal_soc_data {
84 	u32 version;
85 };
86 
87 static struct thermal_soc_data thermal_imx6q_data = {
88 	.version = TEMPMON_IMX6Q,
89 };
90 
91 static struct thermal_soc_data thermal_imx6sx_data = {
92 	.version = TEMPMON_IMX6SX,
93 };
94 
95 struct imx_thermal_data {
96 	struct thermal_zone_device *tz;
97 	struct thermal_cooling_device *cdev;
98 	enum thermal_device_mode mode;
99 	struct regmap *tempmon;
100 	u32 c1, c2; /* See formula in imx_get_sensor_data() */
101 	int temp_passive;
102 	int temp_critical;
103 	int alarm_temp;
104 	int last_temp;
105 	bool irq_enabled;
106 	int irq;
107 	struct clk *thermal_clk;
108 	const struct thermal_soc_data *socdata;
109 };
110 
111 static void imx_set_panic_temp(struct imx_thermal_data *data,
112 			       int panic_temp)
113 {
114 	struct regmap *map = data->tempmon;
115 	int critical_value;
116 
117 	critical_value = (data->c2 - panic_temp) / data->c1;
118 	regmap_write(map, TEMPSENSE2 + REG_CLR, TEMPSENSE2_PANIC_VALUE_MASK);
119 	regmap_write(map, TEMPSENSE2 + REG_SET, critical_value <<
120 			TEMPSENSE2_PANIC_VALUE_SHIFT);
121 }
122 
123 static void imx_set_alarm_temp(struct imx_thermal_data *data,
124 			       int alarm_temp)
125 {
126 	struct regmap *map = data->tempmon;
127 	int alarm_value;
128 
129 	data->alarm_temp = alarm_temp;
130 	alarm_value = (data->c2 - alarm_temp) / data->c1;
131 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
132 	regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
133 			TEMPSENSE0_ALARM_VALUE_SHIFT);
134 }
135 
136 static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
137 {
138 	struct imx_thermal_data *data = tz->devdata;
139 	struct regmap *map = data->tempmon;
140 	unsigned int n_meas;
141 	bool wait;
142 	u32 val;
143 
144 	if (data->mode == THERMAL_DEVICE_ENABLED) {
145 		/* Check if a measurement is currently in progress */
146 		regmap_read(map, TEMPSENSE0, &val);
147 		wait = !(val & TEMPSENSE0_FINISHED);
148 	} else {
149 		/*
150 		 * Every time we measure the temperature, we will power on the
151 		 * temperature sensor, enable measurements, take a reading,
152 		 * disable measurements, power off the temperature sensor.
153 		 */
154 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
155 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
156 
157 		wait = true;
158 	}
159 
160 	/*
161 	 * According to the temp sensor designers, it may require up to ~17us
162 	 * to complete a measurement.
163 	 */
164 	if (wait)
165 		usleep_range(20, 50);
166 
167 	regmap_read(map, TEMPSENSE0, &val);
168 
169 	if (data->mode != THERMAL_DEVICE_ENABLED) {
170 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
171 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
172 	}
173 
174 	if ((val & TEMPSENSE0_FINISHED) == 0) {
175 		dev_dbg(&tz->device, "temp measurement never finished\n");
176 		return -EAGAIN;
177 	}
178 
179 	n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
180 
181 	/* See imx_get_sensor_data() for formula derivation */
182 	*temp = data->c2 - n_meas * data->c1;
183 
184 	/* Update alarm value to next higher trip point for TEMPMON_IMX6Q */
185 	if (data->socdata->version == TEMPMON_IMX6Q) {
186 		if (data->alarm_temp == data->temp_passive &&
187 			*temp >= data->temp_passive)
188 			imx_set_alarm_temp(data, data->temp_critical);
189 		if (data->alarm_temp == data->temp_critical &&
190 			*temp < data->temp_passive) {
191 			imx_set_alarm_temp(data, data->temp_passive);
192 			dev_dbg(&tz->device, "thermal alarm off: T < %d\n",
193 				data->alarm_temp / 1000);
194 		}
195 	}
196 
197 	if (*temp != data->last_temp) {
198 		dev_dbg(&tz->device, "millicelsius: %d\n", *temp);
199 		data->last_temp = *temp;
200 	}
201 
202 	/* Reenable alarm IRQ if temperature below alarm temperature */
203 	if (!data->irq_enabled && *temp < data->alarm_temp) {
204 		data->irq_enabled = true;
205 		enable_irq(data->irq);
206 	}
207 
208 	return 0;
209 }
210 
211 static int imx_get_mode(struct thermal_zone_device *tz,
212 			enum thermal_device_mode *mode)
213 {
214 	struct imx_thermal_data *data = tz->devdata;
215 
216 	*mode = data->mode;
217 
218 	return 0;
219 }
220 
221 static int imx_set_mode(struct thermal_zone_device *tz,
222 			enum thermal_device_mode mode)
223 {
224 	struct imx_thermal_data *data = tz->devdata;
225 	struct regmap *map = data->tempmon;
226 
227 	if (mode == THERMAL_DEVICE_ENABLED) {
228 		tz->polling_delay = IMX_POLLING_DELAY;
229 		tz->passive_delay = IMX_PASSIVE_DELAY;
230 
231 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
232 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
233 
234 		if (!data->irq_enabled) {
235 			data->irq_enabled = true;
236 			enable_irq(data->irq);
237 		}
238 	} else {
239 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
240 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
241 
242 		tz->polling_delay = 0;
243 		tz->passive_delay = 0;
244 
245 		if (data->irq_enabled) {
246 			disable_irq(data->irq);
247 			data->irq_enabled = false;
248 		}
249 	}
250 
251 	data->mode = mode;
252 	thermal_zone_device_update(tz);
253 
254 	return 0;
255 }
256 
257 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
258 			     enum thermal_trip_type *type)
259 {
260 	*type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
261 					     THERMAL_TRIP_CRITICAL;
262 	return 0;
263 }
264 
265 static int imx_get_crit_temp(struct thermal_zone_device *tz, int *temp)
266 {
267 	struct imx_thermal_data *data = tz->devdata;
268 
269 	*temp = data->temp_critical;
270 	return 0;
271 }
272 
273 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
274 			     int *temp)
275 {
276 	struct imx_thermal_data *data = tz->devdata;
277 
278 	*temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
279 					     data->temp_critical;
280 	return 0;
281 }
282 
283 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
284 			     int temp)
285 {
286 	struct imx_thermal_data *data = tz->devdata;
287 
288 	if (trip == IMX_TRIP_CRITICAL)
289 		return -EPERM;
290 
291 	if (temp < 0 || temp > IMX_TEMP_PASSIVE)
292 		return -EINVAL;
293 
294 	data->temp_passive = temp;
295 
296 	imx_set_alarm_temp(data, temp);
297 
298 	return 0;
299 }
300 
301 static int imx_bind(struct thermal_zone_device *tz,
302 		    struct thermal_cooling_device *cdev)
303 {
304 	int ret;
305 
306 	ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
307 					       THERMAL_NO_LIMIT,
308 					       THERMAL_NO_LIMIT,
309 					       THERMAL_WEIGHT_DEFAULT);
310 	if (ret) {
311 		dev_err(&tz->device,
312 			"binding zone %s with cdev %s failed:%d\n",
313 			tz->type, cdev->type, ret);
314 		return ret;
315 	}
316 
317 	return 0;
318 }
319 
320 static int imx_unbind(struct thermal_zone_device *tz,
321 		      struct thermal_cooling_device *cdev)
322 {
323 	int ret;
324 
325 	ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
326 	if (ret) {
327 		dev_err(&tz->device,
328 			"unbinding zone %s with cdev %s failed:%d\n",
329 			tz->type, cdev->type, ret);
330 		return ret;
331 	}
332 
333 	return 0;
334 }
335 
336 static struct thermal_zone_device_ops imx_tz_ops = {
337 	.bind = imx_bind,
338 	.unbind = imx_unbind,
339 	.get_temp = imx_get_temp,
340 	.get_mode = imx_get_mode,
341 	.set_mode = imx_set_mode,
342 	.get_trip_type = imx_get_trip_type,
343 	.get_trip_temp = imx_get_trip_temp,
344 	.get_crit_temp = imx_get_crit_temp,
345 	.set_trip_temp = imx_set_trip_temp,
346 };
347 
348 static int imx_get_sensor_data(struct platform_device *pdev)
349 {
350 	struct imx_thermal_data *data = platform_get_drvdata(pdev);
351 	struct regmap *map;
352 	int t1, n1;
353 	int ret;
354 	u32 val;
355 	u64 temp64;
356 
357 	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
358 					      "fsl,tempmon-data");
359 	if (IS_ERR(map)) {
360 		ret = PTR_ERR(map);
361 		dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
362 		return ret;
363 	}
364 
365 	ret = regmap_read(map, OCOTP_ANA1, &val);
366 	if (ret) {
367 		dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
368 		return ret;
369 	}
370 
371 	if (val == 0 || val == ~0) {
372 		dev_err(&pdev->dev, "invalid sensor calibration data\n");
373 		return -EINVAL;
374 	}
375 
376 	/*
377 	 * Sensor data layout:
378 	 *   [31:20] - sensor value @ 25C
379 	 * Use universal formula now and only need sensor value @ 25C
380 	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
381 	 */
382 	n1 = val >> 20;
383 	t1 = 25; /* t1 always 25C */
384 
385 	/*
386 	 * Derived from linear interpolation:
387 	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
388 	 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
389 	 * (Nmeas - n1) / (Tmeas - t1) = slope
390 	 * We want to reduce this down to the minimum computation necessary
391 	 * for each temperature read.  Also, we want Tmeas in millicelsius
392 	 * and we don't want to lose precision from integer division. So...
393 	 * Tmeas = (Nmeas - n1) / slope + t1
394 	 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
395 	 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
396 	 * Let constant c1 = (-1000 / slope)
397 	 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
398 	 * Let constant c2 = n1 *c1 + 1000 * t1
399 	 * milli_Tmeas = c2 - Nmeas * c1
400 	 */
401 	temp64 = FACTOR0;
402 	temp64 *= 1000;
403 	do_div(temp64, FACTOR1 * n1 - FACTOR2);
404 	data->c1 = temp64;
405 	data->c2 = n1 * data->c1 + 1000 * t1;
406 
407 	/*
408 	 * Set the default passive cooling trip point,
409 	 * can be changed from userspace.
410 	 */
411 	data->temp_passive = IMX_TEMP_PASSIVE;
412 
413 	/*
414 	 * The maximum die temperature set to 20 C higher than
415 	 * IMX_TEMP_PASSIVE.
416 	 */
417 	data->temp_critical = 1000 * 20 + data->temp_passive;
418 
419 	return 0;
420 }
421 
422 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
423 {
424 	struct imx_thermal_data *data = dev;
425 
426 	disable_irq_nosync(irq);
427 	data->irq_enabled = false;
428 
429 	return IRQ_WAKE_THREAD;
430 }
431 
432 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
433 {
434 	struct imx_thermal_data *data = dev;
435 
436 	dev_dbg(&data->tz->device, "THERMAL ALARM: T > %d\n",
437 		data->alarm_temp / 1000);
438 
439 	thermal_zone_device_update(data->tz);
440 
441 	return IRQ_HANDLED;
442 }
443 
444 static const struct of_device_id of_imx_thermal_match[] = {
445 	{ .compatible = "fsl,imx6q-tempmon", .data = &thermal_imx6q_data, },
446 	{ .compatible = "fsl,imx6sx-tempmon", .data = &thermal_imx6sx_data, },
447 	{ /* end */ }
448 };
449 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
450 
451 static int imx_thermal_probe(struct platform_device *pdev)
452 {
453 	const struct of_device_id *of_id =
454 		of_match_device(of_imx_thermal_match, &pdev->dev);
455 	struct imx_thermal_data *data;
456 	struct regmap *map;
457 	int measure_freq;
458 	int ret;
459 
460 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
461 	if (!data)
462 		return -ENOMEM;
463 
464 	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
465 	if (IS_ERR(map)) {
466 		ret = PTR_ERR(map);
467 		dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
468 		return ret;
469 	}
470 	data->tempmon = map;
471 
472 	data->socdata = of_id->data;
473 
474 	/* make sure the IRQ flag is clear before enabling irq on i.MX6SX */
475 	if (data->socdata->version == TEMPMON_IMX6SX) {
476 		regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPHIGH |
477 			MISC1_IRQ_TEMPLOW | MISC1_IRQ_TEMPPANIC);
478 		/*
479 		 * reset value of LOW ALARM is incorrect, set it to lowest
480 		 * value to avoid false trigger of low alarm.
481 		 */
482 		regmap_write(map, TEMPSENSE2 + REG_SET,
483 			TEMPSENSE2_LOW_VALUE_MASK);
484 	}
485 
486 	data->irq = platform_get_irq(pdev, 0);
487 	if (data->irq < 0)
488 		return data->irq;
489 
490 	platform_set_drvdata(pdev, data);
491 
492 	ret = imx_get_sensor_data(pdev);
493 	if (ret) {
494 		dev_err(&pdev->dev, "failed to get sensor data\n");
495 		return ret;
496 	}
497 
498 	/* Make sure sensor is in known good state for measurements */
499 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
500 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
501 	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
502 	regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
503 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
504 
505 	data->cdev = cpufreq_cooling_register(cpu_present_mask);
506 	if (IS_ERR(data->cdev)) {
507 		ret = PTR_ERR(data->cdev);
508 		if (ret != -EPROBE_DEFER)
509 			dev_err(&pdev->dev,
510 				"failed to register cpufreq cooling device: %d\n",
511 				ret);
512 		return ret;
513 	}
514 
515 	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
516 	if (IS_ERR(data->thermal_clk)) {
517 		ret = PTR_ERR(data->thermal_clk);
518 		if (ret != -EPROBE_DEFER)
519 			dev_err(&pdev->dev,
520 				"failed to get thermal clk: %d\n", ret);
521 		cpufreq_cooling_unregister(data->cdev);
522 		return ret;
523 	}
524 
525 	/*
526 	 * Thermal sensor needs clk on to get correct value, normally
527 	 * we should enable its clk before taking measurement and disable
528 	 * clk after measurement is done, but if alarm function is enabled,
529 	 * hardware will auto measure the temperature periodically, so we
530 	 * need to keep the clk always on for alarm function.
531 	 */
532 	ret = clk_prepare_enable(data->thermal_clk);
533 	if (ret) {
534 		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
535 		cpufreq_cooling_unregister(data->cdev);
536 		return ret;
537 	}
538 
539 	data->tz = thermal_zone_device_register("imx_thermal_zone",
540 						IMX_TRIP_NUM,
541 						BIT(IMX_TRIP_PASSIVE), data,
542 						&imx_tz_ops, NULL,
543 						IMX_PASSIVE_DELAY,
544 						IMX_POLLING_DELAY);
545 	if (IS_ERR(data->tz)) {
546 		ret = PTR_ERR(data->tz);
547 		dev_err(&pdev->dev,
548 			"failed to register thermal zone device %d\n", ret);
549 		clk_disable_unprepare(data->thermal_clk);
550 		cpufreq_cooling_unregister(data->cdev);
551 		return ret;
552 	}
553 
554 	/* Enable measurements at ~ 10 Hz */
555 	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
556 	measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
557 	regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
558 	imx_set_alarm_temp(data, data->temp_passive);
559 
560 	if (data->socdata->version == TEMPMON_IMX6SX)
561 		imx_set_panic_temp(data, data->temp_critical);
562 
563 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
564 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
565 
566 	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
567 			imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
568 			0, "imx_thermal", data);
569 	if (ret < 0) {
570 		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
571 		clk_disable_unprepare(data->thermal_clk);
572 		thermal_zone_device_unregister(data->tz);
573 		cpufreq_cooling_unregister(data->cdev);
574 		return ret;
575 	}
576 
577 	data->irq_enabled = true;
578 	data->mode = THERMAL_DEVICE_ENABLED;
579 
580 	return 0;
581 }
582 
583 static int imx_thermal_remove(struct platform_device *pdev)
584 {
585 	struct imx_thermal_data *data = platform_get_drvdata(pdev);
586 	struct regmap *map = data->tempmon;
587 
588 	/* Disable measurements */
589 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
590 	if (!IS_ERR(data->thermal_clk))
591 		clk_disable_unprepare(data->thermal_clk);
592 
593 	thermal_zone_device_unregister(data->tz);
594 	cpufreq_cooling_unregister(data->cdev);
595 
596 	return 0;
597 }
598 
599 #ifdef CONFIG_PM_SLEEP
600 static int imx_thermal_suspend(struct device *dev)
601 {
602 	struct imx_thermal_data *data = dev_get_drvdata(dev);
603 	struct regmap *map = data->tempmon;
604 
605 	/*
606 	 * Need to disable thermal sensor, otherwise, when thermal core
607 	 * try to get temperature before thermal sensor resume, a wrong
608 	 * temperature will be read as the thermal sensor is powered
609 	 * down.
610 	 */
611 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
612 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
613 	data->mode = THERMAL_DEVICE_DISABLED;
614 	clk_disable_unprepare(data->thermal_clk);
615 
616 	return 0;
617 }
618 
619 static int imx_thermal_resume(struct device *dev)
620 {
621 	struct imx_thermal_data *data = dev_get_drvdata(dev);
622 	struct regmap *map = data->tempmon;
623 
624 	clk_prepare_enable(data->thermal_clk);
625 	/* Enabled thermal sensor after resume */
626 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
627 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
628 	data->mode = THERMAL_DEVICE_ENABLED;
629 
630 	return 0;
631 }
632 #endif
633 
634 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
635 			 imx_thermal_suspend, imx_thermal_resume);
636 
637 static struct platform_driver imx_thermal = {
638 	.driver = {
639 		.name	= "imx_thermal",
640 		.pm	= &imx_thermal_pm_ops,
641 		.of_match_table = of_imx_thermal_match,
642 	},
643 	.probe		= imx_thermal_probe,
644 	.remove		= imx_thermal_remove,
645 };
646 module_platform_driver(imx_thermal);
647 
648 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
649 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
650 MODULE_LICENSE("GPL v2");
651 MODULE_ALIAS("platform:imx-thermal");
652