xref: /openbmc/linux/drivers/thermal/imx_thermal.c (revision abfbd895)
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_MEM0			0x0480
59 #define OCOTP_ANA1			0x04e0
60 
61 /* The driver supports 1 passive trip point and 1 critical trip point */
62 enum imx_thermal_trip {
63 	IMX_TRIP_PASSIVE,
64 	IMX_TRIP_CRITICAL,
65 	IMX_TRIP_NUM,
66 };
67 
68 #define IMX_POLLING_DELAY		2000 /* millisecond */
69 #define IMX_PASSIVE_DELAY		1000
70 
71 #define FACTOR0				10000000
72 #define FACTOR1				15976
73 #define FACTOR2				4297157
74 
75 #define TEMPMON_IMX6Q			1
76 #define TEMPMON_IMX6SX			2
77 
78 struct thermal_soc_data {
79 	u32 version;
80 };
81 
82 static struct thermal_soc_data thermal_imx6q_data = {
83 	.version = TEMPMON_IMX6Q,
84 };
85 
86 static struct thermal_soc_data thermal_imx6sx_data = {
87 	.version = TEMPMON_IMX6SX,
88 };
89 
90 struct imx_thermal_data {
91 	struct thermal_zone_device *tz;
92 	struct thermal_cooling_device *cdev;
93 	enum thermal_device_mode mode;
94 	struct regmap *tempmon;
95 	u32 c1, c2; /* See formula in imx_get_sensor_data() */
96 	int temp_passive;
97 	int temp_critical;
98 	int temp_max;
99 	int alarm_temp;
100 	int last_temp;
101 	bool irq_enabled;
102 	int irq;
103 	struct clk *thermal_clk;
104 	const struct thermal_soc_data *socdata;
105 	const char *temp_grade;
106 };
107 
108 static void imx_set_panic_temp(struct imx_thermal_data *data,
109 			       int panic_temp)
110 {
111 	struct regmap *map = data->tempmon;
112 	int critical_value;
113 
114 	critical_value = (data->c2 - panic_temp) / data->c1;
115 	regmap_write(map, TEMPSENSE2 + REG_CLR, TEMPSENSE2_PANIC_VALUE_MASK);
116 	regmap_write(map, TEMPSENSE2 + REG_SET, critical_value <<
117 			TEMPSENSE2_PANIC_VALUE_SHIFT);
118 }
119 
120 static void imx_set_alarm_temp(struct imx_thermal_data *data,
121 			       int alarm_temp)
122 {
123 	struct regmap *map = data->tempmon;
124 	int alarm_value;
125 
126 	data->alarm_temp = alarm_temp;
127 	alarm_value = (data->c2 - alarm_temp) / data->c1;
128 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
129 	regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
130 			TEMPSENSE0_ALARM_VALUE_SHIFT);
131 }
132 
133 static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
134 {
135 	struct imx_thermal_data *data = tz->devdata;
136 	struct regmap *map = data->tempmon;
137 	unsigned int n_meas;
138 	bool wait;
139 	u32 val;
140 
141 	if (data->mode == THERMAL_DEVICE_ENABLED) {
142 		/* Check if a measurement is currently in progress */
143 		regmap_read(map, TEMPSENSE0, &val);
144 		wait = !(val & TEMPSENSE0_FINISHED);
145 	} else {
146 		/*
147 		 * Every time we measure the temperature, we will power on the
148 		 * temperature sensor, enable measurements, take a reading,
149 		 * disable measurements, power off the temperature sensor.
150 		 */
151 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
152 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
153 
154 		wait = true;
155 	}
156 
157 	/*
158 	 * According to the temp sensor designers, it may require up to ~17us
159 	 * to complete a measurement.
160 	 */
161 	if (wait)
162 		usleep_range(20, 50);
163 
164 	regmap_read(map, TEMPSENSE0, &val);
165 
166 	if (data->mode != THERMAL_DEVICE_ENABLED) {
167 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
168 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
169 	}
170 
171 	if ((val & TEMPSENSE0_FINISHED) == 0) {
172 		dev_dbg(&tz->device, "temp measurement never finished\n");
173 		return -EAGAIN;
174 	}
175 
176 	n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
177 
178 	/* See imx_get_sensor_data() for formula derivation */
179 	*temp = data->c2 - n_meas * data->c1;
180 
181 	/* Update alarm value to next higher trip point for TEMPMON_IMX6Q */
182 	if (data->socdata->version == TEMPMON_IMX6Q) {
183 		if (data->alarm_temp == data->temp_passive &&
184 			*temp >= data->temp_passive)
185 			imx_set_alarm_temp(data, data->temp_critical);
186 		if (data->alarm_temp == data->temp_critical &&
187 			*temp < data->temp_passive) {
188 			imx_set_alarm_temp(data, data->temp_passive);
189 			dev_dbg(&tz->device, "thermal alarm off: T < %d\n",
190 				data->alarm_temp / 1000);
191 		}
192 	}
193 
194 	if (*temp != data->last_temp) {
195 		dev_dbg(&tz->device, "millicelsius: %d\n", *temp);
196 		data->last_temp = *temp;
197 	}
198 
199 	/* Reenable alarm IRQ if temperature below alarm temperature */
200 	if (!data->irq_enabled && *temp < data->alarm_temp) {
201 		data->irq_enabled = true;
202 		enable_irq(data->irq);
203 	}
204 
205 	return 0;
206 }
207 
208 static int imx_get_mode(struct thermal_zone_device *tz,
209 			enum thermal_device_mode *mode)
210 {
211 	struct imx_thermal_data *data = tz->devdata;
212 
213 	*mode = data->mode;
214 
215 	return 0;
216 }
217 
218 static int imx_set_mode(struct thermal_zone_device *tz,
219 			enum thermal_device_mode mode)
220 {
221 	struct imx_thermal_data *data = tz->devdata;
222 	struct regmap *map = data->tempmon;
223 
224 	if (mode == THERMAL_DEVICE_ENABLED) {
225 		tz->polling_delay = IMX_POLLING_DELAY;
226 		tz->passive_delay = IMX_PASSIVE_DELAY;
227 
228 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
229 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
230 
231 		if (!data->irq_enabled) {
232 			data->irq_enabled = true;
233 			enable_irq(data->irq);
234 		}
235 	} else {
236 		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
237 		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
238 
239 		tz->polling_delay = 0;
240 		tz->passive_delay = 0;
241 
242 		if (data->irq_enabled) {
243 			disable_irq(data->irq);
244 			data->irq_enabled = false;
245 		}
246 	}
247 
248 	data->mode = mode;
249 	thermal_zone_device_update(tz);
250 
251 	return 0;
252 }
253 
254 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
255 			     enum thermal_trip_type *type)
256 {
257 	*type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
258 					     THERMAL_TRIP_CRITICAL;
259 	return 0;
260 }
261 
262 static int imx_get_crit_temp(struct thermal_zone_device *tz, int *temp)
263 {
264 	struct imx_thermal_data *data = tz->devdata;
265 
266 	*temp = data->temp_critical;
267 	return 0;
268 }
269 
270 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
271 			     int *temp)
272 {
273 	struct imx_thermal_data *data = tz->devdata;
274 
275 	*temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
276 					     data->temp_critical;
277 	return 0;
278 }
279 
280 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
281 			     int temp)
282 {
283 	struct imx_thermal_data *data = tz->devdata;
284 
285 	/* do not allow changing critical threshold */
286 	if (trip == IMX_TRIP_CRITICAL)
287 		return -EPERM;
288 
289 	/* do not allow passive to be set higher than critical */
290 	if (temp < 0 || temp > data->temp_critical)
291 		return -EINVAL;
292 
293 	data->temp_passive = temp;
294 
295 	imx_set_alarm_temp(data, temp);
296 
297 	return 0;
298 }
299 
300 static int imx_bind(struct thermal_zone_device *tz,
301 		    struct thermal_cooling_device *cdev)
302 {
303 	int ret;
304 
305 	ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
306 					       THERMAL_NO_LIMIT,
307 					       THERMAL_NO_LIMIT,
308 					       THERMAL_WEIGHT_DEFAULT);
309 	if (ret) {
310 		dev_err(&tz->device,
311 			"binding zone %s with cdev %s failed:%d\n",
312 			tz->type, cdev->type, ret);
313 		return ret;
314 	}
315 
316 	return 0;
317 }
318 
319 static int imx_unbind(struct thermal_zone_device *tz,
320 		      struct thermal_cooling_device *cdev)
321 {
322 	int ret;
323 
324 	ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
325 	if (ret) {
326 		dev_err(&tz->device,
327 			"unbinding zone %s with cdev %s failed:%d\n",
328 			tz->type, cdev->type, ret);
329 		return ret;
330 	}
331 
332 	return 0;
333 }
334 
335 static struct thermal_zone_device_ops imx_tz_ops = {
336 	.bind = imx_bind,
337 	.unbind = imx_unbind,
338 	.get_temp = imx_get_temp,
339 	.get_mode = imx_get_mode,
340 	.set_mode = imx_set_mode,
341 	.get_trip_type = imx_get_trip_type,
342 	.get_trip_temp = imx_get_trip_temp,
343 	.get_crit_temp = imx_get_crit_temp,
344 	.set_trip_temp = imx_set_trip_temp,
345 };
346 
347 static int imx_get_sensor_data(struct platform_device *pdev)
348 {
349 	struct imx_thermal_data *data = platform_get_drvdata(pdev);
350 	struct regmap *map;
351 	int t1, n1;
352 	int ret;
353 	u32 val;
354 	u64 temp64;
355 
356 	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
357 					      "fsl,tempmon-data");
358 	if (IS_ERR(map)) {
359 		ret = PTR_ERR(map);
360 		dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
361 		return ret;
362 	}
363 
364 	ret = regmap_read(map, OCOTP_ANA1, &val);
365 	if (ret) {
366 		dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
367 		return ret;
368 	}
369 
370 	if (val == 0 || val == ~0) {
371 		dev_err(&pdev->dev, "invalid sensor calibration data\n");
372 		return -EINVAL;
373 	}
374 
375 	/*
376 	 * Sensor data layout:
377 	 *   [31:20] - sensor value @ 25C
378 	 * Use universal formula now and only need sensor value @ 25C
379 	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
380 	 */
381 	n1 = val >> 20;
382 	t1 = 25; /* t1 always 25C */
383 
384 	/*
385 	 * Derived from linear interpolation:
386 	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
387 	 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
388 	 * (Nmeas - n1) / (Tmeas - t1) = slope
389 	 * We want to reduce this down to the minimum computation necessary
390 	 * for each temperature read.  Also, we want Tmeas in millicelsius
391 	 * and we don't want to lose precision from integer division. So...
392 	 * Tmeas = (Nmeas - n1) / slope + t1
393 	 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
394 	 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
395 	 * Let constant c1 = (-1000 / slope)
396 	 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
397 	 * Let constant c2 = n1 *c1 + 1000 * t1
398 	 * milli_Tmeas = c2 - Nmeas * c1
399 	 */
400 	temp64 = FACTOR0;
401 	temp64 *= 1000;
402 	do_div(temp64, FACTOR1 * n1 - FACTOR2);
403 	data->c1 = temp64;
404 	data->c2 = n1 * data->c1 + 1000 * t1;
405 
406 	/* use OTP for thermal grade */
407 	ret = regmap_read(map, OCOTP_MEM0, &val);
408 	if (ret) {
409 		dev_err(&pdev->dev, "failed to read temp grade: %d\n", ret);
410 		return ret;
411 	}
412 
413 	/* The maximum die temp is specified by the Temperature Grade */
414 	switch ((val >> 6) & 0x3) {
415 	case 0: /* Commercial (0 to 95C) */
416 		data->temp_grade = "Commercial";
417 		data->temp_max = 95000;
418 		break;
419 	case 1: /* Extended Commercial (-20 to 105C) */
420 		data->temp_grade = "Extended Commercial";
421 		data->temp_max = 105000;
422 		break;
423 	case 2: /* Industrial (-40 to 105C) */
424 		data->temp_grade = "Industrial";
425 		data->temp_max = 105000;
426 		break;
427 	case 3: /* Automotive (-40 to 125C) */
428 		data->temp_grade = "Automotive";
429 		data->temp_max = 125000;
430 		break;
431 	}
432 
433 	/*
434 	 * Set the critical trip point at 5C under max
435 	 * Set the passive trip point at 10C under max (can change via sysfs)
436 	 */
437 	data->temp_critical = data->temp_max - (1000 * 5);
438 	data->temp_passive = data->temp_max - (1000 * 10);
439 
440 	return 0;
441 }
442 
443 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
444 {
445 	struct imx_thermal_data *data = dev;
446 
447 	disable_irq_nosync(irq);
448 	data->irq_enabled = false;
449 
450 	return IRQ_WAKE_THREAD;
451 }
452 
453 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
454 {
455 	struct imx_thermal_data *data = dev;
456 
457 	dev_dbg(&data->tz->device, "THERMAL ALARM: T > %d\n",
458 		data->alarm_temp / 1000);
459 
460 	thermal_zone_device_update(data->tz);
461 
462 	return IRQ_HANDLED;
463 }
464 
465 static const struct of_device_id of_imx_thermal_match[] = {
466 	{ .compatible = "fsl,imx6q-tempmon", .data = &thermal_imx6q_data, },
467 	{ .compatible = "fsl,imx6sx-tempmon", .data = &thermal_imx6sx_data, },
468 	{ /* end */ }
469 };
470 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
471 
472 static int imx_thermal_probe(struct platform_device *pdev)
473 {
474 	const struct of_device_id *of_id =
475 		of_match_device(of_imx_thermal_match, &pdev->dev);
476 	struct imx_thermal_data *data;
477 	struct regmap *map;
478 	int measure_freq;
479 	int ret;
480 
481 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
482 	if (!data)
483 		return -ENOMEM;
484 
485 	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
486 	if (IS_ERR(map)) {
487 		ret = PTR_ERR(map);
488 		dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
489 		return ret;
490 	}
491 	data->tempmon = map;
492 
493 	data->socdata = of_id->data;
494 
495 	/* make sure the IRQ flag is clear before enabling irq on i.MX6SX */
496 	if (data->socdata->version == TEMPMON_IMX6SX) {
497 		regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPHIGH |
498 			MISC1_IRQ_TEMPLOW | MISC1_IRQ_TEMPPANIC);
499 		/*
500 		 * reset value of LOW ALARM is incorrect, set it to lowest
501 		 * value to avoid false trigger of low alarm.
502 		 */
503 		regmap_write(map, TEMPSENSE2 + REG_SET,
504 			TEMPSENSE2_LOW_VALUE_MASK);
505 	}
506 
507 	data->irq = platform_get_irq(pdev, 0);
508 	if (data->irq < 0)
509 		return data->irq;
510 
511 	platform_set_drvdata(pdev, data);
512 
513 	ret = imx_get_sensor_data(pdev);
514 	if (ret) {
515 		dev_err(&pdev->dev, "failed to get sensor data\n");
516 		return ret;
517 	}
518 
519 	/* Make sure sensor is in known good state for measurements */
520 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
521 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
522 	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
523 	regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
524 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
525 
526 	data->cdev = cpufreq_cooling_register(cpu_present_mask);
527 	if (IS_ERR(data->cdev)) {
528 		ret = PTR_ERR(data->cdev);
529 		if (ret != -EPROBE_DEFER)
530 			dev_err(&pdev->dev,
531 				"failed to register cpufreq cooling device: %d\n",
532 				ret);
533 		return ret;
534 	}
535 
536 	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
537 	if (IS_ERR(data->thermal_clk)) {
538 		ret = PTR_ERR(data->thermal_clk);
539 		if (ret != -EPROBE_DEFER)
540 			dev_err(&pdev->dev,
541 				"failed to get thermal clk: %d\n", ret);
542 		cpufreq_cooling_unregister(data->cdev);
543 		return ret;
544 	}
545 
546 	/*
547 	 * Thermal sensor needs clk on to get correct value, normally
548 	 * we should enable its clk before taking measurement and disable
549 	 * clk after measurement is done, but if alarm function is enabled,
550 	 * hardware will auto measure the temperature periodically, so we
551 	 * need to keep the clk always on for alarm function.
552 	 */
553 	ret = clk_prepare_enable(data->thermal_clk);
554 	if (ret) {
555 		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
556 		cpufreq_cooling_unregister(data->cdev);
557 		return ret;
558 	}
559 
560 	data->tz = thermal_zone_device_register("imx_thermal_zone",
561 						IMX_TRIP_NUM,
562 						BIT(IMX_TRIP_PASSIVE), data,
563 						&imx_tz_ops, NULL,
564 						IMX_PASSIVE_DELAY,
565 						IMX_POLLING_DELAY);
566 	if (IS_ERR(data->tz)) {
567 		ret = PTR_ERR(data->tz);
568 		dev_err(&pdev->dev,
569 			"failed to register thermal zone device %d\n", ret);
570 		clk_disable_unprepare(data->thermal_clk);
571 		cpufreq_cooling_unregister(data->cdev);
572 		return ret;
573 	}
574 
575 	dev_info(&pdev->dev, "%s CPU temperature grade - max:%dC"
576 		 " critical:%dC passive:%dC\n", data->temp_grade,
577 		 data->temp_max / 1000, data->temp_critical / 1000,
578 		 data->temp_passive / 1000);
579 
580 	/* Enable measurements at ~ 10 Hz */
581 	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
582 	measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
583 	regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
584 	imx_set_alarm_temp(data, data->temp_passive);
585 
586 	if (data->socdata->version == TEMPMON_IMX6SX)
587 		imx_set_panic_temp(data, data->temp_critical);
588 
589 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
590 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
591 
592 	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
593 			imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
594 			0, "imx_thermal", data);
595 	if (ret < 0) {
596 		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
597 		clk_disable_unprepare(data->thermal_clk);
598 		thermal_zone_device_unregister(data->tz);
599 		cpufreq_cooling_unregister(data->cdev);
600 		return ret;
601 	}
602 
603 	data->irq_enabled = true;
604 	data->mode = THERMAL_DEVICE_ENABLED;
605 
606 	return 0;
607 }
608 
609 static int imx_thermal_remove(struct platform_device *pdev)
610 {
611 	struct imx_thermal_data *data = platform_get_drvdata(pdev);
612 	struct regmap *map = data->tempmon;
613 
614 	/* Disable measurements */
615 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
616 	if (!IS_ERR(data->thermal_clk))
617 		clk_disable_unprepare(data->thermal_clk);
618 
619 	thermal_zone_device_unregister(data->tz);
620 	cpufreq_cooling_unregister(data->cdev);
621 
622 	return 0;
623 }
624 
625 #ifdef CONFIG_PM_SLEEP
626 static int imx_thermal_suspend(struct device *dev)
627 {
628 	struct imx_thermal_data *data = dev_get_drvdata(dev);
629 	struct regmap *map = data->tempmon;
630 
631 	/*
632 	 * Need to disable thermal sensor, otherwise, when thermal core
633 	 * try to get temperature before thermal sensor resume, a wrong
634 	 * temperature will be read as the thermal sensor is powered
635 	 * down.
636 	 */
637 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
638 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
639 	data->mode = THERMAL_DEVICE_DISABLED;
640 	clk_disable_unprepare(data->thermal_clk);
641 
642 	return 0;
643 }
644 
645 static int imx_thermal_resume(struct device *dev)
646 {
647 	struct imx_thermal_data *data = dev_get_drvdata(dev);
648 	struct regmap *map = data->tempmon;
649 
650 	clk_prepare_enable(data->thermal_clk);
651 	/* Enabled thermal sensor after resume */
652 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
653 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
654 	data->mode = THERMAL_DEVICE_ENABLED;
655 
656 	return 0;
657 }
658 #endif
659 
660 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
661 			 imx_thermal_suspend, imx_thermal_resume);
662 
663 static struct platform_driver imx_thermal = {
664 	.driver = {
665 		.name	= "imx_thermal",
666 		.pm	= &imx_thermal_pm_ops,
667 		.of_match_table = of_imx_thermal_match,
668 	},
669 	.probe		= imx_thermal_probe,
670 	.remove		= imx_thermal_remove,
671 };
672 module_platform_driver(imx_thermal);
673 
674 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
675 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
676 MODULE_LICENSE("GPL v2");
677 MODULE_ALIAS("platform:imx-thermal");
678