xref: /linux/drivers/thermal/tegra/tegra30-tsensor.c (revision fbf46565c67c626849c7ce2a326972d3008d2a91)
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_device.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_core.h"
32 #include "../thermal_hwmon.h"
33 
34 #define TSENSOR_SENSOR0_CONFIG0				0x0
35 #define TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP		BIT(0)
36 #define TSENSOR_SENSOR0_CONFIG0_HW_FREQ_DIV_EN		BIT(1)
37 #define TSENSOR_SENSOR0_CONFIG0_THERMAL_RST_EN		BIT(2)
38 #define TSENSOR_SENSOR0_CONFIG0_DVFS_EN			BIT(3)
39 #define TSENSOR_SENSOR0_CONFIG0_INTR_OVERFLOW_EN	BIT(4)
40 #define TSENSOR_SENSOR0_CONFIG0_INTR_HW_FREQ_DIV_EN	BIT(5)
41 #define TSENSOR_SENSOR0_CONFIG0_INTR_THERMAL_RST_EN	BIT(6)
42 #define TSENSOR_SENSOR0_CONFIG0_M			GENMASK(23,  8)
43 #define TSENSOR_SENSOR0_CONFIG0_N			GENMASK(31, 24)
44 
45 #define TSENSOR_SENSOR0_CONFIG1				0x8
46 #define TSENSOR_SENSOR0_CONFIG1_TH1			GENMASK(15,  0)
47 #define TSENSOR_SENSOR0_CONFIG1_TH2			GENMASK(31, 16)
48 
49 #define TSENSOR_SENSOR0_CONFIG2				0xc
50 #define TSENSOR_SENSOR0_CONFIG2_TH3			GENMASK(15,  0)
51 
52 #define TSENSOR_SENSOR0_STATUS0				0x18
53 #define TSENSOR_SENSOR0_STATUS0_STATE			GENMASK(2, 0)
54 #define TSENSOR_SENSOR0_STATUS0_INTR			BIT(8)
55 #define TSENSOR_SENSOR0_STATUS0_CURRENT_VALID		BIT(9)
56 
57 #define TSENSOR_SENSOR0_TS_STATUS1			0x1c
58 #define TSENSOR_SENSOR0_TS_STATUS1_CURRENT_COUNT	GENMASK(31, 16)
59 
60 #define TEGRA30_FUSE_TEST_PROG_VER			0x28
61 
62 #define TEGRA30_FUSE_TSENSOR_CALIB			0x98
63 #define TEGRA30_FUSE_TSENSOR_CALIB_LOW			GENMASK(15,  0)
64 #define TEGRA30_FUSE_TSENSOR_CALIB_HIGH			GENMASK(31, 16)
65 
66 #define TEGRA30_FUSE_SPARE_BIT				0x144
67 
68 struct tegra_tsensor;
69 
70 struct tegra_tsensor_calibration_data {
71 	int a, b, m, n, p, r;
72 };
73 
74 struct tegra_tsensor_channel {
75 	void __iomem *regs;
76 	unsigned int id;
77 	struct tegra_tsensor *ts;
78 	struct thermal_zone_device *tzd;
79 };
80 
81 struct tegra_tsensor {
82 	void __iomem *regs;
83 	bool swap_channels;
84 	struct clk *clk;
85 	struct device *dev;
86 	struct reset_control *rst;
87 	struct tegra_tsensor_channel ch[2];
88 	struct tegra_tsensor_calibration_data calib;
89 };
90 
91 static int tegra_tsensor_hw_enable(const struct tegra_tsensor *ts)
92 {
93 	u32 val;
94 	int err;
95 
96 	err = reset_control_assert(ts->rst);
97 	if (err) {
98 		dev_err(ts->dev, "failed to assert hardware reset: %d\n", err);
99 		return err;
100 	}
101 
102 	err = clk_prepare_enable(ts->clk);
103 	if (err) {
104 		dev_err(ts->dev, "failed to enable clock: %d\n", err);
105 		return err;
106 	}
107 
108 	fsleep(1000);
109 
110 	err = reset_control_deassert(ts->rst);
111 	if (err) {
112 		dev_err(ts->dev, "failed to deassert hardware reset: %d\n", err);
113 		goto disable_clk;
114 	}
115 
116 	/*
117 	 * Sensors are enabled after reset by default, but not gauging
118 	 * until clock counter is programmed.
119 	 *
120 	 * M: number of reference clock pulses after which every
121 	 *    temperature / voltage measurement is made
122 	 *
123 	 * N: number of reference clock counts for which the counter runs
124 	 */
125 	val  = FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_M, 12500);
126 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_N, 255);
127 
128 	/* apply the same configuration to both channels */
129 	writel_relaxed(val, ts->regs + 0x40 + TSENSOR_SENSOR0_CONFIG0);
130 	writel_relaxed(val, ts->regs + 0x80 + TSENSOR_SENSOR0_CONFIG0);
131 
132 	return 0;
133 
134 disable_clk:
135 	clk_disable_unprepare(ts->clk);
136 
137 	return err;
138 }
139 
140 static int tegra_tsensor_hw_disable(const struct tegra_tsensor *ts)
141 {
142 	int err;
143 
144 	err = reset_control_assert(ts->rst);
145 	if (err) {
146 		dev_err(ts->dev, "failed to assert hardware reset: %d\n", err);
147 		return err;
148 	}
149 
150 	clk_disable_unprepare(ts->clk);
151 
152 	return 0;
153 }
154 
155 static void devm_tegra_tsensor_hw_disable(void *data)
156 {
157 	const struct tegra_tsensor *ts = data;
158 
159 	tegra_tsensor_hw_disable(ts);
160 }
161 
162 static int tegra_tsensor_get_temp(struct thermal_zone_device *tz, int *temp)
163 {
164 	const struct tegra_tsensor_channel *tsc = tz->devdata;
165 	const struct tegra_tsensor *ts = tsc->ts;
166 	int err, c1, c2, c3, c4, counter;
167 	u32 val;
168 
169 	/*
170 	 * Counter will be invalid if hardware is misprogrammed or not enough
171 	 * time passed since the time when sensor was enabled.
172 	 */
173 	err = readl_relaxed_poll_timeout(tsc->regs + TSENSOR_SENSOR0_STATUS0, val,
174 					 val & TSENSOR_SENSOR0_STATUS0_CURRENT_VALID,
175 					 21 * USEC_PER_MSEC,
176 					 21 * USEC_PER_MSEC * 50);
177 	if (err) {
178 		dev_err_once(ts->dev, "ch%u: counter invalid\n", tsc->id);
179 		return err;
180 	}
181 
182 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_TS_STATUS1);
183 	counter = FIELD_GET(TSENSOR_SENSOR0_TS_STATUS1_CURRENT_COUNT, val);
184 
185 	/*
186 	 * This shouldn't happen with a valid counter status, nevertheless
187 	 * lets verify the value since it's in a separate (from status)
188 	 * register.
189 	 */
190 	if (counter == 0xffff) {
191 		dev_err_once(ts->dev, "ch%u: counter overflow\n", tsc->id);
192 		return -EINVAL;
193 	}
194 
195 	/*
196 	 * temperature = a * counter + b
197 	 * temperature = m * (temperature ^ 2) + n * temperature + p
198 	 */
199 	c1 = DIV_ROUND_CLOSEST(ts->calib.a * counter + ts->calib.b, 1000000);
200 	c1 = c1 ?: 1;
201 	c2 = DIV_ROUND_CLOSEST(ts->calib.p, c1);
202 	c3 = c1 * ts->calib.m;
203 	c4 = ts->calib.n;
204 
205 	*temp = DIV_ROUND_CLOSEST(c1 * (c2 + c3 + c4), 1000);
206 
207 	return 0;
208 }
209 
210 static int tegra_tsensor_temp_to_counter(const struct tegra_tsensor *ts, int temp)
211 {
212 	int c1, c2;
213 
214 	c1 = DIV_ROUND_CLOSEST(ts->calib.p - temp * 1000, ts->calib.m);
215 	c2 = -ts->calib.r - int_sqrt(ts->calib.r * ts->calib.r - c1);
216 
217 	return DIV_ROUND_CLOSEST(c2 * 1000000 - ts->calib.b, ts->calib.a);
218 }
219 
220 static int tegra_tsensor_set_trips(struct thermal_zone_device *tz, int low, int high)
221 {
222 	const struct tegra_tsensor_channel *tsc = tz->devdata;
223 	const struct tegra_tsensor *ts = tsc->ts;
224 	u32 val;
225 
226 	/*
227 	 * TSENSOR doesn't trigger interrupt on the "low" temperature breach,
228 	 * hence bail out if high temperature is unspecified.
229 	 */
230 	if (high == INT_MAX)
231 		return 0;
232 
233 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG1);
234 	val &= ~TSENSOR_SENSOR0_CONFIG1_TH1;
235 
236 	high = tegra_tsensor_temp_to_counter(ts, high);
237 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG1_TH1, high);
238 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG1);
239 
240 	return 0;
241 }
242 
243 static const struct thermal_zone_device_ops ops = {
244 	.get_temp = tegra_tsensor_get_temp,
245 	.set_trips = tegra_tsensor_set_trips,
246 };
247 
248 static bool
249 tegra_tsensor_handle_channel_interrupt(const struct tegra_tsensor *ts,
250 				       unsigned int id)
251 {
252 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
253 	u32 val;
254 
255 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_STATUS0);
256 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_STATUS0);
257 
258 	if (FIELD_GET(TSENSOR_SENSOR0_STATUS0_STATE, val) == 5)
259 		dev_err_ratelimited(ts->dev, "ch%u: counter overflowed\n", id);
260 
261 	if (!FIELD_GET(TSENSOR_SENSOR0_STATUS0_INTR, val))
262 		return false;
263 
264 	thermal_zone_device_update(tsc->tzd, THERMAL_EVENT_UNSPECIFIED);
265 
266 	return true;
267 }
268 
269 static irqreturn_t tegra_tsensor_isr(int irq, void *data)
270 {
271 	const struct tegra_tsensor *ts = data;
272 	bool handled = false;
273 	unsigned int i;
274 
275 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++)
276 		handled |= tegra_tsensor_handle_channel_interrupt(ts, i);
277 
278 	return handled ? IRQ_HANDLED : IRQ_NONE;
279 }
280 
281 static int tegra_tsensor_disable_hw_channel(const struct tegra_tsensor *ts,
282 					    unsigned int id)
283 {
284 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
285 	struct thermal_zone_device *tzd = tsc->tzd;
286 	u32 val;
287 	int err;
288 
289 	if (!tzd)
290 		goto stop_channel;
291 
292 	err = thermal_zone_device_disable(tzd);
293 	if (err) {
294 		dev_err(ts->dev, "ch%u: failed to disable zone: %d\n", id, err);
295 		return err;
296 	}
297 
298 stop_channel:
299 	/* stop channel gracefully */
300 	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
301 	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP, 1);
302 	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
303 
304 	return 0;
305 }
306 
307 static void tegra_tsensor_get_hw_channel_trips(struct thermal_zone_device *tzd,
308 					       int *hot_trip, int *crit_trip)
309 {
310 	unsigned int i;
311 
312 	/*
313 	 * 90C is the maximal critical temperature of all Tegra30 SoC variants,
314 	 * use it for the default trip if unspecified in a device-tree.
315 	 */
316 	*hot_trip  = 85000;
317 	*crit_trip = 90000;
318 
319 	for (i = 0; i < tzd->num_trips; i++) {
320 		enum thermal_trip_type type;
321 		int trip_temp;
322 
323 		tzd->ops->get_trip_temp(tzd, i, &trip_temp);
324 		tzd->ops->get_trip_type(tzd, i, &type);
325 
326 		if (type == THERMAL_TRIP_HOT)
327 			*hot_trip = trip_temp;
328 
329 		if (type == THERMAL_TRIP_CRITICAL)
330 			*crit_trip = trip_temp;
331 	}
332 
333 	/* clamp hardware trips to the calibration limits */
334 	*hot_trip = clamp(*hot_trip, 25000, 90000);
335 
336 	/*
337 	 * Kernel will perform a normal system shut down if it will
338 	 * see that critical temperature is breached, hence set the
339 	 * hardware limit by 5C higher in order to allow system to
340 	 * shut down gracefully before sending signal to the Power
341 	 * Management controller.
342 	 */
343 	*crit_trip = clamp(*crit_trip + 5000, 25000, 90000);
344 }
345 
346 static int tegra_tsensor_enable_hw_channel(const struct tegra_tsensor *ts,
347 					   unsigned int id)
348 {
349 	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
350 	struct thermal_zone_device *tzd = tsc->tzd;
351 	int err, hot_trip = 0, crit_trip = 0;
352 	u32 val;
353 
354 	if (!tzd) {
355 		val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
356 		val &= ~TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP;
357 		writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
358 
359 		return 0;
360 	}
361 
362 	tegra_tsensor_get_hw_channel_trips(tzd, &hot_trip, &crit_trip);
363 
364 	/* prevent potential racing with tegra_tsensor_set_trips() */
365 	mutex_lock(&tzd->lock);
366 
367 	dev_info_once(ts->dev, "ch%u: PMC emergency shutdown trip set to %dC\n",
368 		      id, DIV_ROUND_CLOSEST(crit_trip, 1000));
369 
370 	hot_trip  = tegra_tsensor_temp_to_counter(ts, hot_trip);
371 	crit_trip = tegra_tsensor_temp_to_counter(ts, 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, 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, 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 	mutex_unlock(&tzd->lock);
410 
411 	err = thermal_zone_device_enable(tzd);
412 	if (err) {
413 		dev_err(ts->dev, "ch%u: failed to enable zone: %d\n", id, err);
414 		return err;
415 	}
416 
417 	return 0;
418 }
419 
420 static bool tegra_tsensor_fuse_read_spare(unsigned int spare)
421 {
422 	u32 val = 0;
423 
424 	tegra_fuse_readl(TEGRA30_FUSE_SPARE_BIT + spare * 4, &val);
425 
426 	return !!val;
427 }
428 
429 static int tegra_tsensor_nvmem_setup(struct tegra_tsensor *ts)
430 {
431 	u32 i, ate_ver = 0, cal = 0, t1_25C = 0, t2_90C = 0;
432 	int err, c1_25C, c2_90C;
433 
434 	err = tegra_fuse_readl(TEGRA30_FUSE_TEST_PROG_VER, &ate_ver);
435 	if (err) {
436 		dev_err_probe(ts->dev, err, "failed to get ATE version\n");
437 		return err;
438 	}
439 
440 	if (ate_ver < 8) {
441 		dev_info(ts->dev, "unsupported ATE version: %u\n", ate_ver);
442 		return -ENODEV;
443 	}
444 
445 	/*
446 	 * We have two TSENSOR channels in a two different spots on SoC.
447 	 * Second channel provides more accurate data on older SoC versions,
448 	 * use it as a primary channel.
449 	 */
450 	if (ate_ver <= 21) {
451 		dev_info_once(ts->dev,
452 			      "older ATE version detected, channels remapped\n");
453 		ts->swap_channels = true;
454 	}
455 
456 	err = tegra_fuse_readl(TEGRA30_FUSE_TSENSOR_CALIB, &cal);
457 	if (err) {
458 		dev_err(ts->dev, "failed to get calibration data: %d\n", err);
459 		return err;
460 	}
461 
462 	/* get calibrated counter values for 25C/90C thresholds */
463 	c1_25C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_LOW, cal);
464 	c2_90C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_HIGH, cal);
465 
466 	/* and calibrated temperatures corresponding to the counter values */
467 	for (i = 0; i < 7; i++) {
468 		t1_25C |= tegra_tsensor_fuse_read_spare(14 + i) << i;
469 		t1_25C |= tegra_tsensor_fuse_read_spare(21 + i) << i;
470 
471 		t2_90C |= tegra_tsensor_fuse_read_spare(0 + i) << i;
472 		t2_90C |= tegra_tsensor_fuse_read_spare(7 + i) << i;
473 	}
474 
475 	if (c2_90C - c1_25C <= t2_90C - t1_25C) {
476 		dev_err(ts->dev, "invalid calibration data: %d %d %u %u\n",
477 			c2_90C, c1_25C, t2_90C, t1_25C);
478 		return -EINVAL;
479 	}
480 
481 	/* all calibration coefficients are premultiplied by 1000000 */
482 
483 	ts->calib.a = DIV_ROUND_CLOSEST((t2_90C - t1_25C) * 1000000,
484 					(c2_90C - c1_25C));
485 
486 	ts->calib.b = t1_25C * 1000000 - ts->calib.a * c1_25C;
487 
488 	if (tegra_sku_info.revision == TEGRA_REVISION_A01) {
489 		ts->calib.m =     -2775;
490 		ts->calib.n =   1338811;
491 		ts->calib.p =  -7300000;
492 	} else {
493 		ts->calib.m =     -3512;
494 		ts->calib.n =   1528943;
495 		ts->calib.p = -11100000;
496 	}
497 
498 	/* except the coefficient of a reduced quadratic equation */
499 	ts->calib.r = DIV_ROUND_CLOSEST(ts->calib.n, ts->calib.m * 2);
500 
501 	dev_info_once(ts->dev,
502 		      "calibration: %d %d %u %u ATE ver: %u SoC rev: %u\n",
503 		      c2_90C, c1_25C, t2_90C, t1_25C, ate_ver,
504 		      tegra_sku_info.revision);
505 
506 	return 0;
507 }
508 
509 static int tegra_tsensor_register_channel(struct tegra_tsensor *ts,
510 					  unsigned int id)
511 {
512 	struct tegra_tsensor_channel *tsc = &ts->ch[id];
513 	unsigned int hw_id = ts->swap_channels ? !id : id;
514 
515 	tsc->ts = ts;
516 	tsc->id = id;
517 	tsc->regs = ts->regs + 0x40 * (hw_id + 1);
518 
519 	tsc->tzd = devm_thermal_of_zone_register(ts->dev, id, tsc, &ops);
520 	if (IS_ERR(tsc->tzd)) {
521 		if (PTR_ERR(tsc->tzd) != -ENODEV)
522 			return dev_err_probe(ts->dev, PTR_ERR(tsc->tzd),
523 					     "failed to register thermal zone\n");
524 
525 		/*
526 		 * It's okay if sensor isn't assigned to any thermal zone
527 		 * in a device-tree.
528 		 */
529 		tsc->tzd = NULL;
530 		return 0;
531 	}
532 
533 	if (devm_thermal_add_hwmon_sysfs(tsc->tzd))
534 		dev_warn(ts->dev, "failed to add hwmon sysfs attributes\n");
535 
536 	return 0;
537 }
538 
539 static int tegra_tsensor_probe(struct platform_device *pdev)
540 {
541 	struct tegra_tsensor *ts;
542 	unsigned int i;
543 	int err, irq;
544 
545 	ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
546 	if (!ts)
547 		return -ENOMEM;
548 
549 	irq = platform_get_irq(pdev, 0);
550 	if (irq < 0)
551 		return irq;
552 
553 	ts->dev = &pdev->dev;
554 	platform_set_drvdata(pdev, ts);
555 
556 	ts->regs = devm_platform_ioremap_resource(pdev, 0);
557 	if (IS_ERR(ts->regs))
558 		return PTR_ERR(ts->regs);
559 
560 	ts->clk = devm_clk_get(&pdev->dev, NULL);
561 	if (IS_ERR(ts->clk))
562 		return dev_err_probe(&pdev->dev, PTR_ERR(ts->clk),
563 				     "failed to get clock\n");
564 
565 	ts->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
566 	if (IS_ERR(ts->rst))
567 		return dev_err_probe(&pdev->dev, PTR_ERR(ts->rst),
568 				     "failed to get reset control\n");
569 
570 	err = tegra_tsensor_nvmem_setup(ts);
571 	if (err)
572 		return err;
573 
574 	err = tegra_tsensor_hw_enable(ts);
575 	if (err)
576 		return err;
577 
578 	err = devm_add_action_or_reset(&pdev->dev,
579 				       devm_tegra_tsensor_hw_disable,
580 				       ts);
581 	if (err)
582 		return err;
583 
584 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
585 		err = tegra_tsensor_register_channel(ts, i);
586 		if (err)
587 			return err;
588 	}
589 
590 	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
591 					tegra_tsensor_isr, IRQF_ONESHOT,
592 					"tegra_tsensor", ts);
593 	if (err)
594 		return dev_err_probe(&pdev->dev, err,
595 				     "failed to request interrupt\n");
596 
597 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
598 		err = tegra_tsensor_enable_hw_channel(ts, i);
599 		if (err)
600 			return err;
601 	}
602 
603 	return 0;
604 }
605 
606 static int __maybe_unused tegra_tsensor_suspend(struct device *dev)
607 {
608 	struct tegra_tsensor *ts = dev_get_drvdata(dev);
609 	unsigned int i;
610 	int err;
611 
612 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
613 		err = tegra_tsensor_disable_hw_channel(ts, i);
614 		if (err)
615 			goto enable_channel;
616 	}
617 
618 	err = tegra_tsensor_hw_disable(ts);
619 	if (err)
620 		goto enable_channel;
621 
622 	return 0;
623 
624 enable_channel:
625 	while (i--)
626 		tegra_tsensor_enable_hw_channel(ts, i);
627 
628 	return err;
629 }
630 
631 static int __maybe_unused tegra_tsensor_resume(struct device *dev)
632 {
633 	struct tegra_tsensor *ts = dev_get_drvdata(dev);
634 	unsigned int i;
635 	int err;
636 
637 	err = tegra_tsensor_hw_enable(ts);
638 	if (err)
639 		return err;
640 
641 	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
642 		err = tegra_tsensor_enable_hw_channel(ts, i);
643 		if (err)
644 			return err;
645 	}
646 
647 	return 0;
648 }
649 
650 static const struct dev_pm_ops tegra_tsensor_pm_ops = {
651 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_tsensor_suspend,
652 				      tegra_tsensor_resume)
653 };
654 
655 static const struct of_device_id tegra_tsensor_of_match[] = {
656 	{ .compatible = "nvidia,tegra30-tsensor", },
657 	{},
658 };
659 MODULE_DEVICE_TABLE(of, tegra_tsensor_of_match);
660 
661 static struct platform_driver tegra_tsensor_driver = {
662 	.probe = tegra_tsensor_probe,
663 	.driver = {
664 		.name = "tegra30-tsensor",
665 		.of_match_table = tegra_tsensor_of_match,
666 		.pm = &tegra_tsensor_pm_ops,
667 	},
668 };
669 module_platform_driver(tegra_tsensor_driver);
670 
671 MODULE_DESCRIPTION("NVIDIA Tegra30 Thermal Sensor driver");
672 MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
673 MODULE_LICENSE("GPL");
674