xref: /openbmc/linux/drivers/thermal/tegra/tegra30-tsensor.c (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
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  
tegra_tsensor_hw_enable(const struct tegra_tsensor * ts)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  
tegra_tsensor_hw_disable(const struct tegra_tsensor * ts)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  
devm_tegra_tsensor_hw_disable(void * data)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  
tegra_tsensor_get_temp(struct thermal_zone_device * tz,int * temp)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  
tegra_tsensor_temp_to_counter(const struct tegra_tsensor * ts,int temp)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  
tegra_tsensor_set_trips(struct thermal_zone_device * tz,int low,int high)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
tegra_tsensor_handle_channel_interrupt(const struct tegra_tsensor * ts,unsigned int id)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  
tegra_tsensor_isr(int irq,void * data)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  
tegra_tsensor_disable_hw_channel(const struct tegra_tsensor * ts,unsigned int id)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  
tegra_tsensor_get_hw_channel_trips(struct thermal_zone_device * tzd,int * hot_trip,int * crit_trip)306  static 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  
tegra_tsensor_enable_hw_channel(const struct tegra_tsensor * ts,unsigned int id)344  static 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  
tegra_tsensor_fuse_read_spare(unsigned int spare)413  static 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  
tegra_tsensor_nvmem_setup(struct tegra_tsensor * ts)422  static 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  
tegra_tsensor_register_channel(struct tegra_tsensor * ts,unsigned int id)502  static 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  
tegra_tsensor_probe(struct platform_device * pdev)531  static 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  
tegra_tsensor_suspend(struct device * dev)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  
tegra_tsensor_resume(struct device * dev)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