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
67struct tegra_tsensor;
68
69struct tegra_tsensor_calibration_data {
70	int a, b, m, n, p, r;
71};
72
73struct tegra_tsensor_channel {
74	void __iomem *regs;
75	unsigned int id;
76	struct tegra_tsensor *ts;
77	struct thermal_zone_device *tzd;
78};
79
80struct 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
90static 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
133disable_clk:
134	clk_disable_unprepare(ts->clk);
135
136	return err;
137}
138
139static 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
154static 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
161static 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
209static 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
219static 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
242static const struct thermal_zone_device_ops ops = {
243	.get_temp = tegra_tsensor_get_temp,
244	.set_trips = tegra_tsensor_set_trips,
245};
246
247static bool
248tegra_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
268static 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
280static 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
297stop_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
306static void tegra_tsensor_get_hw_channel_trips(struct thermal_zone_device *tzd,
307					       int *hot_trip, int *crit_trip)
308{
309	unsigned int i;
310
311	/*
312	 * 90C is the maximal critical temperature of all Tegra30 SoC variants,
313	 * use it for the default trip if unspecified in a device-tree.
314	 */
315	*hot_trip  = 85000;
316	*crit_trip = 90000;
317
318	for (i = 0; i < thermal_zone_get_num_trips(tzd); i++) {
319
320		struct thermal_trip trip;
321
322		thermal_zone_get_trip(tzd, i, &trip);
323
324		if (trip.type == THERMAL_TRIP_HOT)
325			*hot_trip = trip.temperature;
326
327		if (trip.type == THERMAL_TRIP_CRITICAL)
328			*crit_trip = trip.temperature;
329	}
330
331	/* clamp hardware trips to the calibration limits */
332	*hot_trip = clamp(*hot_trip, 25000, 90000);
333
334	/*
335	 * Kernel will perform a normal system shut down if it will
336	 * see that critical temperature is breached, hence set the
337	 * hardware limit by 5C higher in order to allow system to
338	 * shut down gracefully before sending signal to the Power
339	 * Management controller.
340	 */
341	*crit_trip = clamp(*crit_trip + 5000, 25000, 90000);
342}
343
344static int tegra_tsensor_enable_hw_channel(const struct tegra_tsensor *ts,
345					   unsigned int id)
346{
347	const struct tegra_tsensor_channel *tsc = &ts->ch[id];
348	struct thermal_zone_device *tzd = tsc->tzd;
349	int err, hot_trip = 0, crit_trip = 0;
350	u32 val;
351
352	if (!tzd) {
353		val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
354		val &= ~TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP;
355		writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
356
357		return 0;
358	}
359
360	tegra_tsensor_get_hw_channel_trips(tzd, &hot_trip, &crit_trip);
361
362	dev_info_once(ts->dev, "ch%u: PMC emergency shutdown trip set to %dC\n",
363		      id, DIV_ROUND_CLOSEST(crit_trip, 1000));
364
365	hot_trip  = tegra_tsensor_temp_to_counter(ts, hot_trip);
366	crit_trip = tegra_tsensor_temp_to_counter(ts, crit_trip);
367
368	/* program LEVEL2 counter threshold */
369	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG1);
370	val &= ~TSENSOR_SENSOR0_CONFIG1_TH2;
371	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG1_TH2, hot_trip);
372	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG1);
373
374	/* program LEVEL3 counter threshold */
375	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG2);
376	val &= ~TSENSOR_SENSOR0_CONFIG2_TH3;
377	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG2_TH3, crit_trip);
378	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG2);
379
380	/*
381	 * Enable sensor, emergency shutdown, interrupts for level 1/2/3
382	 * breaches and counter overflow condition.
383	 *
384	 * Disable DIV2 throttle for now since we need to figure out how
385	 * to integrate it properly with the thermal framework.
386	 *
387	 * Thermal levels supported by hardware:
388	 *
389	 *     Level 0 = cold
390	 *     Level 1 = passive cooling (cpufreq DVFS)
391	 *     Level 2 = passive cooling assisted by hardware (DIV2)
392	 *     Level 3 = emergency shutdown assisted by hardware (PMC)
393	 */
394	val = readl_relaxed(tsc->regs + TSENSOR_SENSOR0_CONFIG0);
395	val &= ~TSENSOR_SENSOR0_CONFIG0_SENSOR_STOP;
396	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_DVFS_EN, 1);
397	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_HW_FREQ_DIV_EN, 0);
398	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_THERMAL_RST_EN, 1);
399	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_OVERFLOW_EN, 1);
400	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_HW_FREQ_DIV_EN, 1);
401	val |= FIELD_PREP(TSENSOR_SENSOR0_CONFIG0_INTR_THERMAL_RST_EN, 1);
402	writel_relaxed(val, tsc->regs + TSENSOR_SENSOR0_CONFIG0);
403
404	err = thermal_zone_device_enable(tzd);
405	if (err) {
406		dev_err(ts->dev, "ch%u: failed to enable zone: %d\n", id, err);
407		return err;
408	}
409
410	return 0;
411}
412
413static bool tegra_tsensor_fuse_read_spare(unsigned int spare)
414{
415	u32 val = 0;
416
417	tegra_fuse_readl(TEGRA30_FUSE_SPARE_BIT + spare * 4, &val);
418
419	return !!val;
420}
421
422static int tegra_tsensor_nvmem_setup(struct tegra_tsensor *ts)
423{
424	u32 i, ate_ver = 0, cal = 0, t1_25C = 0, t2_90C = 0;
425	int err, c1_25C, c2_90C;
426
427	err = tegra_fuse_readl(TEGRA30_FUSE_TEST_PROG_VER, &ate_ver);
428	if (err) {
429		dev_err_probe(ts->dev, err, "failed to get ATE version\n");
430		return err;
431	}
432
433	if (ate_ver < 8) {
434		dev_info(ts->dev, "unsupported ATE version: %u\n", ate_ver);
435		return -ENODEV;
436	}
437
438	/*
439	 * We have two TSENSOR channels in a two different spots on SoC.
440	 * Second channel provides more accurate data on older SoC versions,
441	 * use it as a primary channel.
442	 */
443	if (ate_ver <= 21) {
444		dev_info_once(ts->dev,
445			      "older ATE version detected, channels remapped\n");
446		ts->swap_channels = true;
447	}
448
449	err = tegra_fuse_readl(TEGRA30_FUSE_TSENSOR_CALIB, &cal);
450	if (err) {
451		dev_err(ts->dev, "failed to get calibration data: %d\n", err);
452		return err;
453	}
454
455	/* get calibrated counter values for 25C/90C thresholds */
456	c1_25C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_LOW, cal);
457	c2_90C = FIELD_GET(TEGRA30_FUSE_TSENSOR_CALIB_HIGH, cal);
458
459	/* and calibrated temperatures corresponding to the counter values */
460	for (i = 0; i < 7; i++) {
461		t1_25C |= tegra_tsensor_fuse_read_spare(14 + i) << i;
462		t1_25C |= tegra_tsensor_fuse_read_spare(21 + i) << i;
463
464		t2_90C |= tegra_tsensor_fuse_read_spare(0 + i) << i;
465		t2_90C |= tegra_tsensor_fuse_read_spare(7 + i) << i;
466	}
467
468	if (c2_90C - c1_25C <= t2_90C - t1_25C) {
469		dev_err(ts->dev, "invalid calibration data: %d %d %u %u\n",
470			c2_90C, c1_25C, t2_90C, t1_25C);
471		return -EINVAL;
472	}
473
474	/* all calibration coefficients are premultiplied by 1000000 */
475
476	ts->calib.a = DIV_ROUND_CLOSEST((t2_90C - t1_25C) * 1000000,
477					(c2_90C - c1_25C));
478
479	ts->calib.b = t1_25C * 1000000 - ts->calib.a * c1_25C;
480
481	if (tegra_sku_info.revision == TEGRA_REVISION_A01) {
482		ts->calib.m =     -2775;
483		ts->calib.n =   1338811;
484		ts->calib.p =  -7300000;
485	} else {
486		ts->calib.m =     -3512;
487		ts->calib.n =   1528943;
488		ts->calib.p = -11100000;
489	}
490
491	/* except the coefficient of a reduced quadratic equation */
492	ts->calib.r = DIV_ROUND_CLOSEST(ts->calib.n, ts->calib.m * 2);
493
494	dev_info_once(ts->dev,
495		      "calibration: %d %d %u %u ATE ver: %u SoC rev: %u\n",
496		      c2_90C, c1_25C, t2_90C, t1_25C, ate_ver,
497		      tegra_sku_info.revision);
498
499	return 0;
500}
501
502static int tegra_tsensor_register_channel(struct tegra_tsensor *ts,
503					  unsigned int id)
504{
505	struct tegra_tsensor_channel *tsc = &ts->ch[id];
506	unsigned int hw_id = ts->swap_channels ? !id : id;
507
508	tsc->ts = ts;
509	tsc->id = id;
510	tsc->regs = ts->regs + 0x40 * (hw_id + 1);
511
512	tsc->tzd = devm_thermal_of_zone_register(ts->dev, id, tsc, &ops);
513	if (IS_ERR(tsc->tzd)) {
514		if (PTR_ERR(tsc->tzd) != -ENODEV)
515			return dev_err_probe(ts->dev, PTR_ERR(tsc->tzd),
516					     "failed to register thermal zone\n");
517
518		/*
519		 * It's okay if sensor isn't assigned to any thermal zone
520		 * in a device-tree.
521		 */
522		tsc->tzd = NULL;
523		return 0;
524	}
525
526	devm_thermal_add_hwmon_sysfs(ts->dev, tsc->tzd);
527
528	return 0;
529}
530
531static int tegra_tsensor_probe(struct platform_device *pdev)
532{
533	struct tegra_tsensor *ts;
534	unsigned int i;
535	int err, irq;
536
537	ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
538	if (!ts)
539		return -ENOMEM;
540
541	irq = platform_get_irq(pdev, 0);
542	if (irq < 0)
543		return irq;
544
545	ts->dev = &pdev->dev;
546	platform_set_drvdata(pdev, ts);
547
548	ts->regs = devm_platform_ioremap_resource(pdev, 0);
549	if (IS_ERR(ts->regs))
550		return PTR_ERR(ts->regs);
551
552	ts->clk = devm_clk_get(&pdev->dev, NULL);
553	if (IS_ERR(ts->clk))
554		return dev_err_probe(&pdev->dev, PTR_ERR(ts->clk),
555				     "failed to get clock\n");
556
557	ts->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
558	if (IS_ERR(ts->rst))
559		return dev_err_probe(&pdev->dev, PTR_ERR(ts->rst),
560				     "failed to get reset control\n");
561
562	err = tegra_tsensor_nvmem_setup(ts);
563	if (err)
564		return err;
565
566	err = tegra_tsensor_hw_enable(ts);
567	if (err)
568		return err;
569
570	err = devm_add_action_or_reset(&pdev->dev,
571				       devm_tegra_tsensor_hw_disable,
572				       ts);
573	if (err)
574		return err;
575
576	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
577		err = tegra_tsensor_register_channel(ts, i);
578		if (err)
579			return err;
580	}
581
582	/*
583	 * Enable the channels before setting the interrupt so
584	 * set_trips() can not be called while we are setting up the
585	 * register TSENSOR_SENSOR0_CONFIG1. With this we close a
586	 * potential race window where we are setting up the TH2 and
587	 * the temperature hits TH1 resulting to an update of the
588	 * TSENSOR_SENSOR0_CONFIG1 register in the ISR.
589	 */
590	for (i = 0; i < ARRAY_SIZE(ts->ch); i++) {
591		err = tegra_tsensor_enable_hw_channel(ts, i);
592		if (err)
593			return err;
594	}
595
596	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
597					tegra_tsensor_isr, IRQF_ONESHOT,
598					"tegra_tsensor", ts);
599	if (err)
600		return dev_err_probe(&pdev->dev, err,
601				     "failed to request interrupt\n");
602
603	return 0;
604}
605
606static 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
624enable_channel:
625	while (i--)
626		tegra_tsensor_enable_hw_channel(ts, i);
627
628	return err;
629}
630
631static 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
650static 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
655static const struct of_device_id tegra_tsensor_of_match[] = {
656	{ .compatible = "nvidia,tegra30-tsensor", },
657	{},
658};
659MODULE_DEVICE_TABLE(of, tegra_tsensor_of_match);
660
661static 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};
669module_platform_driver(tegra_tsensor_driver);
670
671MODULE_DESCRIPTION("NVIDIA Tegra30 Thermal Sensor driver");
672MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
673MODULE_LICENSE("GPL");
674