xref: /linux/drivers/thermal/tegra/tegra30-tsensor.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Tegra30 SoC Thermal Sensor driver
4  *
5  * Based on downstream HWMON driver from NVIDIA.
6  * Copyright (C) 2011 NVIDIA Corporation
7  *
8  * Author: Dmitry Osipenko <digetx@gmail.com>
9  * Copyright (C) 2021 GRATE-DRIVER project
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/errno.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/iopoll.h>
19 #include <linux/math.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm.h>
24 #include <linux/reset.h>
25 #include <linux/slab.h>
26 #include <linux/thermal.h>
27 #include <linux/types.h>
28 
29 #include <soc/tegra/fuse.h>
30 
31 #include "../thermal_hwmon.h"
32 
33 #define TSENSOR_SENSOR0_CONFIG0				0x0
34 #define TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP		BIT(0)
35 #define TSENSOR_SENSOR0_CONFIG0_HW_FREQ_DIV_EN		BIT(1)
36 #define TSENSOR_SENSOR0_CONFIG0_THERMAL_RST_EN		BIT(2)
37 #define TSENSOR_SENSOR0_CONFIG0_DVFS_EN			BIT(3)
38 #define TSENSOR_SENSOR0_CONFIG0_INTR_OVERFLOW_EN	BIT(4)
39 #define TSENSOR_SENSOR0_CONFIG0_INTR_HW_FREQ_DIV_EN	BIT(5)
40 #define TSENSOR_SENSOR0_CONFIG0_INTR_THERMAL_RST_EN	BIT(6)
41 #define TSENSOR_SENSOR0_CONFIG0_M			GENMASK(23,  8)
42 #define TSENSOR_SENSOR0_CONFIG0_N			GENMASK(31, 24)
43 
44 #define TSENSOR_SENSOR0_CONFIG1				0x8
45 #define TSENSOR_SENSOR0_CONFIG1_TH1			GENMASK(15,  0)
46 #define TSENSOR_SENSOR0_CONFIG1_TH2			GENMASK(31, 16)
47 
48 #define TSENSOR_SENSOR0_CONFIG2				0xc
49 #define TSENSOR_SENSOR0_CONFIG2_TH3			GENMASK(15,  0)
50 
51 #define TSENSOR_SENSOR0_STATUS0				0x18
52 #define TSENSOR_SENSOR0_STATUS0_STATE			GENMASK(2, 0)
53 #define TSENSOR_SENSOR0_STATUS0_INTR			BIT(8)
54 #define TSENSOR_SENSOR0_STATUS0_CURRENT_VALID		BIT(9)
55 
56 #define TSENSOR_SENSOR0_TS_STATUS1			0x1c
57 #define TSENSOR_SENSOR0_TS_STATUS1_CURRENT_COUNT	GENMASK(31, 16)
58 
59 #define TEGRA30_FUSE_TEST_PROG_VER			0x28
60 
61 #define TEGRA30_FUSE_TSENSOR_CALIB			0x98
62 #define TEGRA30_FUSE_TSENSOR_CALIB_LOW			GENMASK(15,  0)
63 #define TEGRA30_FUSE_TSENSOR_CALIB_HIGH			GENMASK(31, 16)
64 
65 #define TEGRA30_FUSE_SPARE_BIT				0x144
66 
67 struct tegra_tsensor;
68 
69 struct tegra_tsensor_calibration_data {
70 	int a, b, m, n, p, r;
71 };
72 
73 struct tegra_tsensor_channel {
74 	void __iomem *regs;
75 	unsigned int id;
76 	struct tegra_tsensor *ts;
77 	struct thermal_zone_device *tzd;
78 };
79 
80 struct tegra_tsensor {
81 	void __iomem *regs;
82 	bool swap_channels;
83 	struct clk *clk;
84 	struct device *dev;
85 	struct reset_control *rst;
86 	struct tegra_tsensor_channel ch[2];
87 	struct tegra_tsensor_calibration_data calib;
88 };
89 
90 static int tegra_tsensor_hw_enable(const struct tegra_tsensor *ts)
91 {
92 	u32 val;
93 	int err;
94 
95 	err = reset_control_assert(ts->rst);
96 	if (err) {
97 		dev_err(ts->dev, "failed to assert hardware reset: %d\n", err);
98 		return err;
99 	}
100 
101 	err = clk_prepare_enable(ts->clk);
102 	if (err) {
103 		dev_err(ts->dev, "failed to enable clock: %d\n", err);
104 		return err;
105 	}
106 
107 	fsleep(1000);
108 
109 	err = reset_control_deassert(ts->rst);
110 	if (err) {
111 		dev_err(ts->dev, "failed to deassert hardware reset: %d\n", err);
112 		goto disable_clk;
113 	}
114 
115 	/*
116 	 * Sensors are enabled after reset by default, but not gauging
117 	 * until clock counter is programmed.
118 	 *
119 	 * M: number of reference clock pulses after which every
120 	 *    temperature / voltage measurement is made
121 	 *
122 	 * N: number of reference clock counts for which the counter runs
123 	 */
124 	val  = FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_M, 12500);
125 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_N, 255);
126 
127 	/* apply the same configuration to both channels */
128 	writel_relaxed(val, ts->regs + 0x40 + TSENSOR_SENSOR0_CONFIG0);
129 	writel_relaxed(val, ts->regs + 0x80 + TSENSOR_SENSOR0_CONFIG0);
130 
131 	return 0;
132 
133 disable_clk:
134 	clk_disable_unprepare(ts->clk);
135 
136 	return err;
137 }
138 
139 static int tegra_tsensor_hw_disable(const struct tegra_tsensor *ts)
140 {
141 	int err;
142 
143 	err = reset_control_assert(ts->rst);
144 	if (err) {
145 		dev_err(ts->dev, "failed to assert hardware reset: %d\n", err);
146 		return err;
147 	}
148 
149 	clk_disable_unprepare(ts->clk);
150 
151 	return 0;
152 }
153 
154 static void devm_tegra_tsensor_hw_disable(void *data)
155 {
156 	const struct tegra_tsensor *ts = data;
157 
158 	tegra_tsensor_hw_disable(ts);
159 }
160 
161 static int tegra_tsensor_get_temp(struct thermal_zone_device *tz, int *temp)
162 {
163 	const struct tegra_tsensor_channel *tsc = thermal_zone_device_priv(tz);
164 	const struct tegra_tsensor *ts = tsc->ts;
165 	int err, c1, c2, c3, c4, counter;
166 	u32 val;
167 
168 	/*
169 	 * Counter will be invalid if hardware is misprogrammed or not enough
170 	 * time passed since the time when sensor was enabled.
171 	 */
172 	err = readl_relaxed_poll_timeout(tsc->regs + TSENSOR_SENSOR0_STATUS0, val,
173 					 val & TSENSOR_SENSOR0_STATUS0_CURRENT_VALID,
174 					 21 * USEC_PER_MSEC,
175 					 21 * USEC_PER_MSEC * 50);
176 	if (err) {
177 		dev_err_once(ts->dev, "ch%u: counter invalid\n", tsc->id);
178 		return err;
179 	}
180 
181 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_TS_STATUS1);
182 	counter = FIELD_GET(TSENSOR_SENSOR0_TS_STATUS1_CURRENT_COUNT, val);
183 
184 	/*
185 	 * This shouldn't happen with a valid counter status, nevertheless
186 	 * lets verify the value since it's in a separate (from status)
187 	 * register.
188 	 */
189 	if (counter == 0xffff) {
190 		dev_err_once(ts->dev, "ch%u: counter overflow\n", tsc->id);
191 		return -EINVAL;
192 	}
193 
194 	/*
195 	 * temperature = a * counter + b
196 	 * temperature = m * (temperature ^ 2) + n * temperature + p
197 	 */
198 	c1 = DIV_ROUND_CLOSEST(ts->calib.a * counter + ts->calib.b, 1000000);
199 	c1 = c1 ?: 1;
200 	c2 = DIV_ROUND_CLOSEST(ts->calib.p, c1);
201 	c3 = c1 * ts->calib.m;
202 	c4 = ts->calib.n;
203 
204 	*temp = DIV_ROUND_CLOSEST(c1 * (c2 + c3 + c4), 1000);
205 
206 	return 0;
207 }
208 
209 static int tegra_tsensor_temp_to_counter(const struct tegra_tsensor *ts, int temp)
210 {
211 	int c1, c2;
212 
213 	c1 = DIV_ROUND_CLOSEST(ts->calib.p - temp * 1000, ts->calib.m);
214 	c2 = -ts->calib.r - int_sqrt(ts->calib.r * ts->calib.r - c1);
215 
216 	return DIV_ROUND_CLOSEST(c2 * 1000000 - ts->calib.b, ts->calib.a);
217 }
218 
219 static int tegra_tsensor_set_trips(struct thermal_zone_device *tz, int low, int high)
220 {
221 	const struct tegra_tsensor_channel *tsc = thermal_zone_device_priv(tz);
222 	const struct tegra_tsensor *ts = tsc->ts;
223 	u32 val;
224 
225 	/*
226 	 * TSENSOR doesn't trigger interrupt on the "low" temperature breach,
227 	 * hence bail out if high temperature is unspecified.
228 	 */
229 	if (high == INT_MAX)
230 		return 0;
231 
232 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG1);
233 	val &= ~TSENSOR_SENSOR0_CONFIG1_TH1;
234 
235 	high = tegra_tsensor_temp_to_counter(ts, high);
236 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG1_TH1, high);
237 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG1);
238 
239 	return 0;
240 }
241 
242 static const struct thermal_zone_device_ops ops = {
243 	.get_temp = tegra_tsensor_get_temp,
244 	.set_trips = tegra_tsensor_set_trips,
245 };
246 
247 static bool
248 tegra_tsensor_handle_channel_interrupt(const struct tegra_tsensor *ts,
249 				       unsigned int id)
250 {
251 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
252 	u32 val;
253 
254 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_STATUS0);
255 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_STATUS0);
256 
257 	if (FIELD_GET(TSENSOR_SENSOR0_STATUS0_STATE, val) == 5)
258 		dev_err_ratelimited(ts->dev, "ch%u: counter overflowed\n", id);
259 
260 	if (!FIELD_GET(TSENSOR_SENSOR0_STATUS0_INTR, val))
261 		return false;
262 
263 	thermal_zone_device_update(tsc->tzd, THERMAL_EVENT_UNSPECIFIED);
264 
265 	return true;
266 }
267 
268 static irqreturn_t tegra_tsensor_isr(int irq, void *data)
269 {
270 	const struct tegra_tsensor *ts = data;
271 	bool handled = false;
272 	unsigned int i;
273 
274 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++)
275 		handled |= tegra_tsensor_handle_channel_interrupt(ts, i);
276 
277 	return handled ? IRQ_HANDLED : IRQ_NONE;
278 }
279 
280 static int tegra_tsensor_disable_hw_channel(const struct tegra_tsensor *ts,
281 					    unsigned int id)
282 {
283 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
284 	struct thermal_zone_device *tzd = tsc->tzd;
285 	u32 val;
286 	int err;
287 
288 	if (!tzd)
289 		goto stop_channel;
290 
291 	err = thermal_zone_device_disable(tzd);
292 	if (err) {
293 		dev_err(ts->dev, "ch%u: failed to disable zone: %d\n", id, err);
294 		return err;
295 	}
296 
297 stop_channel:
298 	/* stop channel gracefully */
299 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
300 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP, 1);
301 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
302 
303 	return 0;
304 }
305 
306 struct trip_temps {
307 	int hot_trip;
308 	int crit_trip;
309 };
310 
311 static int tegra_tsensor_get_trips_cb(struct thermal_trip *trip, void *arg)
312 {
313 	struct trip_temps *temps = arg;
314 
315 	if (trip->type == THERMAL_TRIP_HOT)
316 		temps->hot_trip = trip->temperature;
317 	else if (trip->type == THERMAL_TRIP_CRITICAL)
318 		temps->crit_trip = trip->temperature;
319 
320 	return 0;
321 }
322 
323 static void tegra_tsensor_get_hw_channel_trips(struct thermal_zone_device *tzd,
324 					       struct trip_temps *temps)
325 {
326 	/*
327 	 * 90C is the maximal critical temperature of all Tegra30 SoC variants,
328 	 * use it for the default trip if unspecified in a device-tree.
329 	 */
330 	temps->hot_trip  = 85000;
331 	temps->crit_trip = 90000;
332 
333 	thermal_zone_for_each_trip(tzd, tegra_tsensor_get_trips_cb, temps);
334 
335 	/* clamp hardware trips to the calibration limits */
336 	temps->hot_trip = clamp(temps->hot_trip, 25000, 90000);
337 
338 	/*
339 	 * Kernel will perform a normal system shut down if it will
340 	 * see that critical temperature is breached, hence set the
341 	 * hardware limit by 5C higher in order to allow system to
342 	 * shut down gracefully before sending signal to the Power
343 	 * Management controller.
344 	 */
345 	temps->crit_trip = clamp(temps->crit_trip + 5000, 25000, 90000);
346 }
347 
348 static int tegra_tsensor_enable_hw_channel(const struct tegra_tsensor *ts,
349 					   unsigned int id)
350 {
351 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
352 	struct thermal_zone_device *tzd = tsc->tzd;
353 	struct trip_temps temps = { 0 };
354 	int err;
355 	u32 val;
356 
357 	if (!tzd) {
358 		val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
359 		val &= ~TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP;
360 		writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
361 
362 		return 0;
363 	}
364 
365 	tegra_tsensor_get_hw_channel_trips(tzd, &temps);
366 
367 	dev_info_once(ts->dev, "ch%u: PMC emergency shutdown trip set to %dC\n",
368 		      id, DIV_ROUND_CLOSEST(temps.crit_trip, 1000));
369 
370 	temps.hot_trip  = tegra_tsensor_temp_to_counter(ts, temps.hot_trip);
371 	temps.crit_trip = tegra_tsensor_temp_to_counter(ts, temps.crit_trip);
372 
373 	/* program LEVEL2 counter threshold */
374 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG1);
375 	val &= ~TSENSOR_SENSOR0_CONFIG1_TH2;
376 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG1_TH2, temps.hot_trip);
377 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG1);
378 
379 	/* program LEVEL3 counter threshold */
380 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG2);
381 	val &= ~TSENSOR_SENSOR0_CONFIG2_TH3;
382 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG2_TH3, temps.crit_trip);
383 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG2);
384 
385 	/*
386 	 * Enable sensor, emergency shutdown, interrupts for level 1/2/3
387 	 * breaches and counter overflow condition.
388 	 *
389 	 * Disable DIV2 throttle for now since we need to figure out how
390 	 * to integrate it properly with the thermal framework.
391 	 *
392 	 * Thermal levels supported by hardware:
393 	 *
394 	 *     Level 0 = cold
395 	 *     Level 1 = passive cooling (cpufreq DVFS)
396 	 *     Level 2 = passive cooling assisted by hardware (DIV2)
397 	 *     Level 3 = emergency shutdown assisted by hardware (PMC)
398 	 */
399 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
400 	val &= ~TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP;
401 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_DVFS_EN, 1);
402 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_HW_FREQ_DIV_EN, 0);
403 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_THERMAL_RST_EN, 1);
404 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_OVERFLOW_EN, 1);
405 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_HW_FREQ_DIV_EN, 1);
406 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_THERMAL_RST_EN, 1);
407 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
408 
409 	err = thermal_zone_device_enable(tzd);
410 	if (err) {
411 		dev_err(ts->dev, "ch%u: failed to enable zone: %d\n", id, err);
412 		return err;
413 	}
414 
415 	return 0;
416 }
417 
418 static bool tegra_tsensor_fuse_read_spare(unsigned int spare)
419 {
420 	u32 val = 0;
421 
422 	tegra_fuse_readl(TEGRA30_FUSE_SPARE_BIT + spare * 4, &val);
423 
424 	return !!val;
425 }
426 
427 static int tegra_tsensor_nvmem_setup(struct tegra_tsensor *ts)
428 {
429 	u32 i, ate_ver = 0, cal = 0, t1_25C = 0, t2_90C = 0;
430 	int err, c1_25C, c2_90C;
431 
432 	err = tegra_fuse_readl(TEGRA30_FUSE_TEST_PROG_VER, &ate_ver);
433 	if (err) {
434 		dev_err_probe(ts->dev, err, "failed to get ATE version\n");
435 		return err;
436 	}
437 
438 	if (ate_ver < 8) {
439 		dev_info(ts->dev, "unsupported ATE version: %u\n", ate_ver);
440 		return -ENODEV;
441 	}
442 
443 	/*
444 	 * We have two TSENSOR channels in a two different spots on SoC.
445 	 * Second channel provides more accurate data on older SoC versions,
446 	 * use it as a primary channel.
447 	 */
448 	if (ate_ver <= 21) {
449 		dev_info_once(ts->dev,
450 			      "older ATE version detected, channels remapped\n");
451 		ts->swap_channels = true;
452 	}
453 
454 	err = tegra_fuse_readl(TEGRA30_FUSE_TSENSOR_CALIB, &cal);
455 	if (err) {
456 		dev_err(ts->dev, "failed to get calibration data: %d\n", err);
457 		return err;
458 	}
459 
460 	/* get calibrated counter values for 25C/90C thresholds */
461 	c1_25C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_LOW, cal);
462 	c2_90C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_HIGH, cal);
463 
464 	/* and calibrated temperatures corresponding to the counter values */
465 	for (i = 0; i < 7; i++) {
466 		t1_25C |= tegra_tsensor_fuse_read_spare(14 + i) << i;
467 		t1_25C |= tegra_tsensor_fuse_read_spare(21 + i) << i;
468 
469 		t2_90C |= tegra_tsensor_fuse_read_spare(0 + i) << i;
470 		t2_90C |= tegra_tsensor_fuse_read_spare(7 + i) << i;
471 	}
472 
473 	if (c2_90C - c1_25C <= t2_90C - t1_25C) {
474 		dev_err(ts->dev, "invalid calibration data: %d %d %u %u\n",
475 			c2_90C, c1_25C, t2_90C, t1_25C);
476 		return -EINVAL;
477 	}
478 
479 	/* all calibration coefficients are premultiplied by 1000000 */
480 
481 	ts->calib.a = DIV_ROUND_CLOSEST((t2_90C - t1_25C) * 1000000,
482 					(c2_90C - c1_25C));
483 
484 	ts->calib.b = t1_25C * 1000000 - ts->calib.a * c1_25C;
485 
486 	if (tegra_sku_info.revision == TEGRA_REVISION_A01) {
487 		ts->calib.m =     -2775;
488 		ts->calib.n =   1338811;
489 		ts->calib.p =  -7300000;
490 	} else {
491 		ts->calib.m =     -3512;
492 		ts->calib.n =   1528943;
493 		ts->calib.p = -11100000;
494 	}
495 
496 	/* except the coefficient of a reduced quadratic equation */
497 	ts->calib.r = DIV_ROUND_CLOSEST(ts->calib.n, ts->calib.m * 2);
498 
499 	dev_info_once(ts->dev,
500 		      "calibration: %d %d %u %u ATE ver: %u SoC rev: %u\n",
501 		      c2_90C, c1_25C, t2_90C, t1_25C, ate_ver,
502 		      tegra_sku_info.revision);
503 
504 	return 0;
505 }
506 
507 static int tegra_tsensor_register_channel(struct tegra_tsensor *ts,
508 					  unsigned int id)
509 {
510 	struct tegra_tsensor_channel *tsc = &ts->ch[id];
511 	unsigned int hw_id = ts->swap_channels ? !id : id;
512 
513 	tsc->ts = ts;
514 	tsc->id = id;
515 	tsc->regs = ts->regs + 0x40 * (hw_id + 1);
516 
517 	tsc->tzd = devm_thermal_of_zone_register(ts->dev, id, tsc, &ops);
518 	if (IS_ERR(tsc->tzd)) {
519 		if (PTR_ERR(tsc->tzd) != -ENODEV)
520 			return dev_err_probe(ts->dev, PTR_ERR(tsc->tzd),
521 					     "failed to register thermal zone\n");
522 
523 		/*
524 		 * It's okay if sensor isn't assigned to any thermal zone
525 		 * in a device-tree.
526 		 */
527 		tsc->tzd = NULL;
528 		return 0;
529 	}
530 
531 	devm_thermal_add_hwmon_sysfs(ts->dev, tsc->tzd);
532 
533 	return 0;
534 }
535 
536 static int tegra_tsensor_probe(struct platform_device *pdev)
537 {
538 	struct tegra_tsensor *ts;
539 	unsigned int i;
540 	int err, irq;
541 
542 	ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
543 	if (!ts)
544 		return -ENOMEM;
545 
546 	irq = platform_get_irq(pdev, 0);
547 	if (irq < 0)
548 		return irq;
549 
550 	ts->dev = &pdev->dev;
551 	platform_set_drvdata(pdev, ts);
552 
553 	ts->regs = devm_platform_ioremap_resource(pdev, 0);
554 	if (IS_ERR(ts->regs))
555 		return PTR_ERR(ts->regs);
556 
557 	ts->clk = devm_clk_get(&pdev->dev, NULL);
558 	if (IS_ERR(ts->clk))
559 		return dev_err_probe(&pdev->dev, PTR_ERR(ts->clk),
560 				     "failed to get clock\n");
561 
562 	ts->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
563 	if (IS_ERR(ts->rst))
564 		return dev_err_probe(&pdev->dev, PTR_ERR(ts->rst),
565 				     "failed to get reset control\n");
566 
567 	err = tegra_tsensor_nvmem_setup(ts);
568 	if (err)
569 		return err;
570 
571 	err = tegra_tsensor_hw_enable(ts);
572 	if (err)
573 		return err;
574 
575 	err = devm_add_action_or_reset(&pdev->dev,
576 				       devm_tegra_tsensor_hw_disable,
577 				       ts);
578 	if (err)
579 		return err;
580 
581 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
582 		err = tegra_tsensor_register_channel(ts, i);
583 		if (err)
584 			return err;
585 	}
586 
587 	/*
588 	 * Enable the channels before setting the interrupt so
589 	 * set_trips() can not be called while we are setting up the
590 	 * register TSENSOR_SENSOR0_CONFIG1. With this we close a
591 	 * potential race window where we are setting up the TH2 and
592 	 * the temperature hits TH1 resulting to an update of the
593 	 * TSENSOR_SENSOR0_CONFIG1 register in the ISR.
594 	 */
595 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
596 		err = tegra_tsensor_enable_hw_channel(ts, i);
597 		if (err)
598 			return err;
599 	}
600 
601 	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
602 					tegra_tsensor_isr, IRQF_ONESHOT,
603 					"tegra_tsensor", ts);
604 	if (err)
605 		return dev_err_probe(&pdev->dev, err,
606 				     "failed to request interrupt\n");
607 
608 	return 0;
609 }
610 
611 static int __maybe_unused tegra_tsensor_suspend(struct device *dev)
612 {
613 	struct tegra_tsensor *ts = dev_get_drvdata(dev);
614 	unsigned int i;
615 	int err;
616 
617 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
618 		err = tegra_tsensor_disable_hw_channel(ts, i);
619 		if (err)
620 			goto enable_channel;
621 	}
622 
623 	err = tegra_tsensor_hw_disable(ts);
624 	if (err)
625 		goto enable_channel;
626 
627 	return 0;
628 
629 enable_channel:
630 	while (i--)
631 		tegra_tsensor_enable_hw_channel(ts, i);
632 
633 	return err;
634 }
635 
636 static int __maybe_unused tegra_tsensor_resume(struct device *dev)
637 {
638 	struct tegra_tsensor *ts = dev_get_drvdata(dev);
639 	unsigned int i;
640 	int err;
641 
642 	err = tegra_tsensor_hw_enable(ts);
643 	if (err)
644 		return err;
645 
646 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
647 		err = tegra_tsensor_enable_hw_channel(ts, i);
648 		if (err)
649 			return err;
650 	}
651 
652 	return 0;
653 }
654 
655 static const struct dev_pm_ops tegra_tsensor_pm_ops = {
656 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_tsensor_suspend,
657 				      tegra_tsensor_resume)
658 };
659 
660 static const struct of_device_id tegra_tsensor_of_match[] = {
661 	{ .compatible = "nvidia,tegra30-tsensor", },
662 	{},
663 };
664 MODULE_DEVICE_TABLE(of, tegra_tsensor_of_match);
665 
666 static struct platform_driver tegra_tsensor_driver = {
667 	.probe = tegra_tsensor_probe,
668 	.driver = {
669 		.name = "tegra30-tsensor",
670 		.of_match_table = tegra_tsensor_of_match,
671 		.pm = &tegra_tsensor_pm_ops,
672 	},
673 };
674 module_platform_driver(tegra_tsensor_driver);
675 
676 MODULE_DESCRIPTION("NVIDIA Tegra30 Thermal Sensor driver");
677 MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
678 MODULE_LICENSE("GPL");
679