1 /*
2  * TI Bandgap temperature sensor driver
3  *
4  * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
5  * Author: J Keerthy <j-keerthy@ti.com>
6  * Author: Moiz Sonasath <m-sonasath@ti.com>
7  * Couple of fixes, DT and MFD adaptation:
8  *   Eduardo Valentin <eduardo.valentin@ti.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/export.h>
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/interrupt.h>
31 #include <linux/clk.h>
32 #include <linux/gpio.h>
33 #include <linux/platform_device.h>
34 #include <linux/err.h>
35 #include <linux/types.h>
36 #include <linux/spinlock.h>
37 #include <linux/reboot.h>
38 #include <linux/of_device.h>
39 #include <linux/of_platform.h>
40 #include <linux/of_irq.h>
41 #include <linux/of_gpio.h>
42 #include <linux/io.h>
43 
44 #include "ti-bandgap.h"
45 
46 /***   Helper functions to access registers and their bitfields   ***/
47 
48 /**
49  * ti_bandgap_readl() - simple read helper function
50  * @bgp: pointer to ti_bandgap structure
51  * @reg: desired register (offset) to be read
52  *
53  * Helper function to read bandgap registers. It uses the io remapped area.
54  * Return: the register value.
55  */
56 static u32 ti_bandgap_readl(struct ti_bandgap *bgp, u32 reg)
57 {
58 	return readl(bgp->base + reg);
59 }
60 
61 /**
62  * ti_bandgap_writel() - simple write helper function
63  * @bgp: pointer to ti_bandgap structure
64  * @val: desired register value to be written
65  * @reg: desired register (offset) to be written
66  *
67  * Helper function to write bandgap registers. It uses the io remapped area.
68  */
69 static void ti_bandgap_writel(struct ti_bandgap *bgp, u32 val, u32 reg)
70 {
71 	writel(val, bgp->base + reg);
72 }
73 
74 /**
75  * DOC: macro to update bits.
76  *
77  * RMW_BITS() - used to read, modify and update bandgap bitfields.
78  *            The value passed will be shifted.
79  */
80 #define RMW_BITS(bgp, id, reg, mask, val)			\
81 do {								\
82 	struct temp_sensor_registers *t;			\
83 	u32 r;							\
84 								\
85 	t = bgp->conf->sensors[(id)].registers;		\
86 	r = ti_bandgap_readl(bgp, t->reg);			\
87 	r &= ~t->mask;						\
88 	r |= (val) << __ffs(t->mask);				\
89 	ti_bandgap_writel(bgp, r, t->reg);			\
90 } while (0)
91 
92 /***   Basic helper functions   ***/
93 
94 /**
95  * ti_bandgap_power() - controls the power state of a bandgap device
96  * @bgp: pointer to ti_bandgap structure
97  * @on: desired power state (1 - on, 0 - off)
98  *
99  * Used to power on/off a bandgap device instance. Only used on those
100  * that features tempsoff bit.
101  *
102  * Return: 0 on success, -ENOTSUPP if tempsoff is not supported.
103  */
104 static int ti_bandgap_power(struct ti_bandgap *bgp, bool on)
105 {
106 	int i, ret = 0;
107 
108 	if (!TI_BANDGAP_HAS(bgp, POWER_SWITCH)) {
109 		ret = -ENOTSUPP;
110 		goto exit;
111 	}
112 
113 	for (i = 0; i < bgp->conf->sensor_count; i++)
114 		/* active on 0 */
115 		RMW_BITS(bgp, i, temp_sensor_ctrl, bgap_tempsoff_mask, !on);
116 
117 exit:
118 	return ret;
119 }
120 
121 /**
122  * ti_bandgap_read_temp() - helper function to read sensor temperature
123  * @bgp: pointer to ti_bandgap structure
124  * @id: bandgap sensor id
125  *
126  * Function to concentrate the steps to read sensor temperature register.
127  * This function is desired because, depending on bandgap device version,
128  * it might be needed to freeze the bandgap state machine, before fetching
129  * the register value.
130  *
131  * Return: temperature in ADC values.
132  */
133 static u32 ti_bandgap_read_temp(struct ti_bandgap *bgp, int id)
134 {
135 	struct temp_sensor_registers *tsr;
136 	u32 temp, reg;
137 
138 	tsr = bgp->conf->sensors[id].registers;
139 	reg = tsr->temp_sensor_ctrl;
140 
141 	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT)) {
142 		RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 1);
143 		/*
144 		 * In case we cannot read from cur_dtemp / dtemp_0,
145 		 * then we read from the last valid temp read
146 		 */
147 		reg = tsr->ctrl_dtemp_1;
148 	}
149 
150 	/* read temperature */
151 	temp = ti_bandgap_readl(bgp, reg);
152 	temp &= tsr->bgap_dtemp_mask;
153 
154 	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT))
155 		RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 0);
156 
157 	return temp;
158 }
159 
160 /***   IRQ handlers   ***/
161 
162 /**
163  * ti_bandgap_talert_irq_handler() - handles Temperature alert IRQs
164  * @irq: IRQ number
165  * @data: private data (struct ti_bandgap *)
166  *
167  * This is the Talert handler. Use it only if bandgap device features
168  * HAS(TALERT). This handler goes over all sensors and checks their
169  * conditions and acts accordingly. In case there are events pending,
170  * it will reset the event mask to wait for the opposite event (next event).
171  * Every time there is a new event, it will be reported to thermal layer.
172  *
173  * Return: IRQ_HANDLED
174  */
175 static irqreturn_t ti_bandgap_talert_irq_handler(int irq, void *data)
176 {
177 	struct ti_bandgap *bgp = data;
178 	struct temp_sensor_registers *tsr;
179 	u32 t_hot = 0, t_cold = 0, ctrl;
180 	int i;
181 
182 	spin_lock(&bgp->lock);
183 	for (i = 0; i < bgp->conf->sensor_count; i++) {
184 		tsr = bgp->conf->sensors[i].registers;
185 		ctrl = ti_bandgap_readl(bgp, tsr->bgap_status);
186 
187 		/* Read the status of t_hot */
188 		t_hot = ctrl & tsr->status_hot_mask;
189 
190 		/* Read the status of t_cold */
191 		t_cold = ctrl & tsr->status_cold_mask;
192 
193 		if (!t_cold && !t_hot)
194 			continue;
195 
196 		ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
197 		/*
198 		 * One TALERT interrupt: Two sources
199 		 * If the interrupt is due to t_hot then mask t_hot and
200 		 * and unmask t_cold else mask t_cold and unmask t_hot
201 		 */
202 		if (t_hot) {
203 			ctrl &= ~tsr->mask_hot_mask;
204 			ctrl |= tsr->mask_cold_mask;
205 		} else if (t_cold) {
206 			ctrl &= ~tsr->mask_cold_mask;
207 			ctrl |= tsr->mask_hot_mask;
208 		}
209 
210 		ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl);
211 
212 		dev_dbg(bgp->dev,
213 			"%s: IRQ from %s sensor: hotevent %d coldevent %d\n",
214 			__func__, bgp->conf->sensors[i].domain,
215 			t_hot, t_cold);
216 
217 		/* report temperature to whom may concern */
218 		if (bgp->conf->report_temperature)
219 			bgp->conf->report_temperature(bgp, i);
220 	}
221 	spin_unlock(&bgp->lock);
222 
223 	return IRQ_HANDLED;
224 }
225 
226 /**
227  * ti_bandgap_tshut_irq_handler() - handles Temperature shutdown signal
228  * @irq: IRQ number
229  * @data: private data (unused)
230  *
231  * This is the Tshut handler. Use it only if bandgap device features
232  * HAS(TSHUT). If any sensor fires the Tshut signal, we simply shutdown
233  * the system.
234  *
235  * Return: IRQ_HANDLED
236  */
237 static irqreturn_t ti_bandgap_tshut_irq_handler(int irq, void *data)
238 {
239 	pr_emerg("%s: TSHUT temperature reached. Needs shut down...\n",
240 		 __func__);
241 
242 	orderly_poweroff(true);
243 
244 	return IRQ_HANDLED;
245 }
246 
247 /***   Helper functions which manipulate conversion ADC <-> mi Celsius   ***/
248 
249 /**
250  * ti_bandgap_adc_to_mcelsius() - converts an ADC value to mCelsius scale
251  * @bgp: struct ti_bandgap pointer
252  * @adc_val: value in ADC representation
253  * @t: address where to write the resulting temperature in mCelsius
254  *
255  * Simple conversion from ADC representation to mCelsius. In case the ADC value
256  * is out of the ADC conv table range, it returns -ERANGE, 0 on success.
257  * The conversion table is indexed by the ADC values.
258  *
259  * Return: 0 if conversion was successful, else -ERANGE in case the @adc_val
260  * argument is out of the ADC conv table range.
261  */
262 static
263 int ti_bandgap_adc_to_mcelsius(struct ti_bandgap *bgp, int adc_val, int *t)
264 {
265 	const struct ti_bandgap_data *conf = bgp->conf;
266 	int ret = 0;
267 
268 	/* look up for temperature in the table and return the temperature */
269 	if (adc_val < conf->adc_start_val || adc_val > conf->adc_end_val) {
270 		ret = -ERANGE;
271 		goto exit;
272 	}
273 
274 	*t = bgp->conf->conv_table[adc_val - conf->adc_start_val];
275 
276 exit:
277 	return ret;
278 }
279 
280 /**
281  * ti_bandgap_mcelsius_to_adc() - converts a mCelsius value to ADC scale
282  * @bgp: struct ti_bandgap pointer
283  * @temp: value in mCelsius
284  * @adc: address where to write the resulting temperature in ADC representation
285  *
286  * Simple conversion from mCelsius to ADC values. In case the temp value
287  * is out of the ADC conv table range, it returns -ERANGE, 0 on success.
288  * The conversion table is indexed by the ADC values.
289  *
290  * Return: 0 if conversion was successful, else -ERANGE in case the @temp
291  * argument is out of the ADC conv table range.
292  */
293 static
294 int ti_bandgap_mcelsius_to_adc(struct ti_bandgap *bgp, long temp, int *adc)
295 {
296 	const struct ti_bandgap_data *conf = bgp->conf;
297 	const int *conv_table = bgp->conf->conv_table;
298 	int high, low, mid, ret = 0;
299 
300 	low = 0;
301 	high = conf->adc_end_val - conf->adc_start_val;
302 	mid = (high + low) / 2;
303 
304 	if (temp < conv_table[low] || temp > conv_table[high]) {
305 		ret = -ERANGE;
306 		goto exit;
307 	}
308 
309 	while (low < high) {
310 		if (temp < conv_table[mid])
311 			high = mid - 1;
312 		else
313 			low = mid + 1;
314 		mid = (low + high) / 2;
315 	}
316 
317 	*adc = conf->adc_start_val + low;
318 
319 exit:
320 	return ret;
321 }
322 
323 /**
324  * ti_bandgap_add_hyst() - add hysteresis (in mCelsius) to an ADC value
325  * @bgp: struct ti_bandgap pointer
326  * @adc_val: temperature value in ADC representation
327  * @hyst_val: hysteresis value in mCelsius
328  * @sum: address where to write the resulting temperature (in ADC scale)
329  *
330  * Adds an hysteresis value (in mCelsius) to a ADC temperature value.
331  *
332  * Return: 0 on success, -ERANGE otherwise.
333  */
334 static
335 int ti_bandgap_add_hyst(struct ti_bandgap *bgp, int adc_val, int hyst_val,
336 			u32 *sum)
337 {
338 	int temp, ret;
339 
340 	/*
341 	 * Need to add in the mcelsius domain, so we have a temperature
342 	 * the conv_table range
343 	 */
344 	ret = ti_bandgap_adc_to_mcelsius(bgp, adc_val, &temp);
345 	if (ret < 0)
346 		goto exit;
347 
348 	temp += hyst_val;
349 
350 	ret = ti_bandgap_mcelsius_to_adc(bgp, temp, sum);
351 
352 exit:
353 	return ret;
354 }
355 
356 /***   Helper functions handling device Alert/Shutdown signals   ***/
357 
358 /**
359  * ti_bandgap_unmask_interrupts() - unmasks the events of thot & tcold
360  * @bgp: struct ti_bandgap pointer
361  * @id: bandgap sensor id
362  * @t_hot: hot temperature value to trigger alert signal
363  * @t_cold: cold temperature value to trigger alert signal
364  *
365  * Checks the requested t_hot and t_cold values and configures the IRQ event
366  * masks accordingly. Call this function only if bandgap features HAS(TALERT).
367  */
368 static void ti_bandgap_unmask_interrupts(struct ti_bandgap *bgp, int id,
369 					 u32 t_hot, u32 t_cold)
370 {
371 	struct temp_sensor_registers *tsr;
372 	u32 temp, reg_val;
373 
374 	/* Read the current on die temperature */
375 	temp = ti_bandgap_read_temp(bgp, id);
376 
377 	tsr = bgp->conf->sensors[id].registers;
378 	reg_val = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
379 
380 	if (temp < t_hot)
381 		reg_val |= tsr->mask_hot_mask;
382 	else
383 		reg_val &= ~tsr->mask_hot_mask;
384 
385 	if (t_cold < temp)
386 		reg_val |= tsr->mask_cold_mask;
387 	else
388 		reg_val &= ~tsr->mask_cold_mask;
389 	ti_bandgap_writel(bgp, reg_val, tsr->bgap_mask_ctrl);
390 }
391 
392 /**
393  * ti_bandgap_update_alert_threshold() - sequence to update thresholds
394  * @bgp: struct ti_bandgap pointer
395  * @id: bandgap sensor id
396  * @val: value (ADC) of a new threshold
397  * @hot: desired threshold to be updated. true if threshold hot, false if
398  *       threshold cold
399  *
400  * It will program the required thresholds (hot and cold) for TALERT signal.
401  * This function can be used to update t_hot or t_cold, depending on @hot value.
402  * It checks the resulting t_hot and t_cold values, based on the new passed @val
403  * and configures the thresholds so that t_hot is always greater than t_cold.
404  * Call this function only if bandgap features HAS(TALERT).
405  *
406  * Return: 0 if no error, else corresponding error
407  */
408 static int ti_bandgap_update_alert_threshold(struct ti_bandgap *bgp, int id,
409 					     int val, bool hot)
410 {
411 	struct temp_sensor_data *ts_data = bgp->conf->sensors[id].ts_data;
412 	struct temp_sensor_registers *tsr;
413 	u32 thresh_val, reg_val, t_hot, t_cold;
414 	int err = 0;
415 
416 	tsr = bgp->conf->sensors[id].registers;
417 
418 	/* obtain the current value */
419 	thresh_val = ti_bandgap_readl(bgp, tsr->bgap_threshold);
420 	t_cold = (thresh_val & tsr->threshold_tcold_mask) >>
421 		__ffs(tsr->threshold_tcold_mask);
422 	t_hot = (thresh_val & tsr->threshold_thot_mask) >>
423 		__ffs(tsr->threshold_thot_mask);
424 	if (hot)
425 		t_hot = val;
426 	else
427 		t_cold = val;
428 
429 	if (t_cold > t_hot) {
430 		if (hot)
431 			err = ti_bandgap_add_hyst(bgp, t_hot,
432 						  -ts_data->hyst_val,
433 						  &t_cold);
434 		else
435 			err = ti_bandgap_add_hyst(bgp, t_cold,
436 						  ts_data->hyst_val,
437 						  &t_hot);
438 	}
439 
440 	/* write the new threshold values */
441 	reg_val = thresh_val &
442 		  ~(tsr->threshold_thot_mask | tsr->threshold_tcold_mask);
443 	reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask)) |
444 		   (t_cold << __ffs(tsr->threshold_tcold_mask));
445 	ti_bandgap_writel(bgp, reg_val, tsr->bgap_threshold);
446 
447 	if (err) {
448 		dev_err(bgp->dev, "failed to reprogram thot threshold\n");
449 		err = -EIO;
450 		goto exit;
451 	}
452 
453 	ti_bandgap_unmask_interrupts(bgp, id, t_hot, t_cold);
454 exit:
455 	return err;
456 }
457 
458 /**
459  * ti_bandgap_validate() - helper to check the sanity of a struct ti_bandgap
460  * @bgp: struct ti_bandgap pointer
461  * @id: bandgap sensor id
462  *
463  * Checks if the bandgap pointer is valid and if the sensor id is also
464  * applicable.
465  *
466  * Return: 0 if no errors, -EINVAL for invalid @bgp pointer or -ERANGE if
467  * @id cannot index @bgp sensors.
468  */
469 static inline int ti_bandgap_validate(struct ti_bandgap *bgp, int id)
470 {
471 	int ret = 0;
472 
473 	if (!bgp || IS_ERR(bgp)) {
474 		pr_err("%s: invalid bandgap pointer\n", __func__);
475 		ret = -EINVAL;
476 		goto exit;
477 	}
478 
479 	if ((id < 0) || (id >= bgp->conf->sensor_count)) {
480 		dev_err(bgp->dev, "%s: sensor id out of range (%d)\n",
481 			__func__, id);
482 		ret = -ERANGE;
483 	}
484 
485 exit:
486 	return ret;
487 }
488 
489 /**
490  * _ti_bandgap_write_threshold() - helper to update TALERT t_cold or t_hot
491  * @bgp: struct ti_bandgap pointer
492  * @id: bandgap sensor id
493  * @val: value (mCelsius) of a new threshold
494  * @hot: desired threshold to be updated. true if threshold hot, false if
495  *       threshold cold
496  *
497  * It will update the required thresholds (hot and cold) for TALERT signal.
498  * This function can be used to update t_hot or t_cold, depending on @hot value.
499  * Validates the mCelsius range and update the requested threshold.
500  * Call this function only if bandgap features HAS(TALERT).
501  *
502  * Return: 0 if no error, else corresponding error value.
503  */
504 static int _ti_bandgap_write_threshold(struct ti_bandgap *bgp, int id, int val,
505 				       bool hot)
506 {
507 	struct temp_sensor_data *ts_data;
508 	struct temp_sensor_registers *tsr;
509 	u32 adc_val;
510 	int ret;
511 
512 	ret = ti_bandgap_validate(bgp, id);
513 	if (ret)
514 		goto exit;
515 
516 	if (!TI_BANDGAP_HAS(bgp, TALERT)) {
517 		ret = -ENOTSUPP;
518 		goto exit;
519 	}
520 
521 	ts_data = bgp->conf->sensors[id].ts_data;
522 	tsr = bgp->conf->sensors[id].registers;
523 	if (hot) {
524 		if (val < ts_data->min_temp + ts_data->hyst_val)
525 			ret = -EINVAL;
526 	} else {
527 		if (val > ts_data->max_temp + ts_data->hyst_val)
528 			ret = -EINVAL;
529 	}
530 
531 	if (ret)
532 		goto exit;
533 
534 	ret = ti_bandgap_mcelsius_to_adc(bgp, val, &adc_val);
535 	if (ret < 0)
536 		goto exit;
537 
538 	spin_lock(&bgp->lock);
539 	ret = ti_bandgap_update_alert_threshold(bgp, id, adc_val, hot);
540 	spin_unlock(&bgp->lock);
541 
542 exit:
543 	return ret;
544 }
545 
546 /**
547  * _ti_bandgap_read_threshold() - helper to read TALERT t_cold or t_hot
548  * @bgp: struct ti_bandgap pointer
549  * @id: bandgap sensor id
550  * @val: value (mCelsius) of a threshold
551  * @hot: desired threshold to be read. true if threshold hot, false if
552  *       threshold cold
553  *
554  * It will fetch the required thresholds (hot and cold) for TALERT signal.
555  * This function can be used to read t_hot or t_cold, depending on @hot value.
556  * Call this function only if bandgap features HAS(TALERT).
557  *
558  * Return: 0 if no error, -ENOTSUPP if it has no TALERT support, or the
559  * corresponding error value if some operation fails.
560  */
561 static int _ti_bandgap_read_threshold(struct ti_bandgap *bgp, int id,
562 				      int *val, bool hot)
563 {
564 	struct temp_sensor_registers *tsr;
565 	u32 temp, mask;
566 	int ret = 0;
567 
568 	ret = ti_bandgap_validate(bgp, id);
569 	if (ret)
570 		goto exit;
571 
572 	if (!TI_BANDGAP_HAS(bgp, TALERT)) {
573 		ret = -ENOTSUPP;
574 		goto exit;
575 	}
576 
577 	tsr = bgp->conf->sensors[id].registers;
578 	if (hot)
579 		mask = tsr->threshold_thot_mask;
580 	else
581 		mask = tsr->threshold_tcold_mask;
582 
583 	temp = ti_bandgap_readl(bgp, tsr->bgap_threshold);
584 	temp = (temp & mask) >> __ffs(mask);
585 	ret |= ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
586 	if (ret) {
587 		dev_err(bgp->dev, "failed to read thot\n");
588 		ret = -EIO;
589 		goto exit;
590 	}
591 
592 	*val = temp;
593 
594 exit:
595 	return ret;
596 }
597 
598 /***   Exposed APIs   ***/
599 
600 /**
601  * ti_bandgap_read_thot() - reads sensor current thot
602  * @bgp: pointer to bandgap instance
603  * @id: sensor id
604  * @thot: resulting current thot value
605  *
606  * Return: 0 on success or the proper error code
607  */
608 int ti_bandgap_read_thot(struct ti_bandgap *bgp, int id, int *thot)
609 {
610 	return _ti_bandgap_read_threshold(bgp, id, thot, true);
611 }
612 
613 /**
614  * ti_bandgap_write_thot() - sets sensor current thot
615  * @bgp: pointer to bandgap instance
616  * @id: sensor id
617  * @val: desired thot value
618  *
619  * Return: 0 on success or the proper error code
620  */
621 int ti_bandgap_write_thot(struct ti_bandgap *bgp, int id, int val)
622 {
623 	return _ti_bandgap_write_threshold(bgp, id, val, true);
624 }
625 
626 /**
627  * ti_bandgap_read_tcold() - reads sensor current tcold
628  * @bgp: pointer to bandgap instance
629  * @id: sensor id
630  * @tcold: resulting current tcold value
631  *
632  * Return: 0 on success or the proper error code
633  */
634 int ti_bandgap_read_tcold(struct ti_bandgap *bgp, int id, int *tcold)
635 {
636 	return _ti_bandgap_read_threshold(bgp, id, tcold, false);
637 }
638 
639 /**
640  * ti_bandgap_write_tcold() - sets the sensor tcold
641  * @bgp: pointer to bandgap instance
642  * @id: sensor id
643  * @val: desired tcold value
644  *
645  * Return: 0 on success or the proper error code
646  */
647 int ti_bandgap_write_tcold(struct ti_bandgap *bgp, int id, int val)
648 {
649 	return _ti_bandgap_write_threshold(bgp, id, val, false);
650 }
651 
652 /**
653  * ti_bandgap_read_counter() - read the sensor counter
654  * @bgp: pointer to bandgap instance
655  * @id: sensor id
656  * @interval: resulting update interval in miliseconds
657  */
658 static void ti_bandgap_read_counter(struct ti_bandgap *bgp, int id,
659 				    int *interval)
660 {
661 	struct temp_sensor_registers *tsr;
662 	int time;
663 
664 	tsr = bgp->conf->sensors[id].registers;
665 	time = ti_bandgap_readl(bgp, tsr->bgap_counter);
666 	time = (time & tsr->counter_mask) >>
667 					__ffs(tsr->counter_mask);
668 	time = time * 1000 / bgp->clk_rate;
669 	*interval = time;
670 }
671 
672 /**
673  * ti_bandgap_read_counter_delay() - read the sensor counter delay
674  * @bgp: pointer to bandgap instance
675  * @id: sensor id
676  * @interval: resulting update interval in miliseconds
677  */
678 static void ti_bandgap_read_counter_delay(struct ti_bandgap *bgp, int id,
679 					  int *interval)
680 {
681 	struct temp_sensor_registers *tsr;
682 	int reg_val;
683 
684 	tsr = bgp->conf->sensors[id].registers;
685 
686 	reg_val = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
687 	reg_val = (reg_val & tsr->mask_counter_delay_mask) >>
688 				__ffs(tsr->mask_counter_delay_mask);
689 	switch (reg_val) {
690 	case 0:
691 		*interval = 0;
692 		break;
693 	case 1:
694 		*interval = 1;
695 		break;
696 	case 2:
697 		*interval = 10;
698 		break;
699 	case 3:
700 		*interval = 100;
701 		break;
702 	case 4:
703 		*interval = 250;
704 		break;
705 	case 5:
706 		*interval = 500;
707 		break;
708 	default:
709 		dev_warn(bgp->dev, "Wrong counter delay value read from register %X",
710 			 reg_val);
711 	}
712 }
713 
714 /**
715  * ti_bandgap_read_update_interval() - read the sensor update interval
716  * @bgp: pointer to bandgap instance
717  * @id: sensor id
718  * @interval: resulting update interval in miliseconds
719  *
720  * Return: 0 on success or the proper error code
721  */
722 int ti_bandgap_read_update_interval(struct ti_bandgap *bgp, int id,
723 				    int *interval)
724 {
725 	int ret = 0;
726 
727 	ret = ti_bandgap_validate(bgp, id);
728 	if (ret)
729 		goto exit;
730 
731 	if (!TI_BANDGAP_HAS(bgp, COUNTER) &&
732 	    !TI_BANDGAP_HAS(bgp, COUNTER_DELAY)) {
733 		ret = -ENOTSUPP;
734 		goto exit;
735 	}
736 
737 	if (TI_BANDGAP_HAS(bgp, COUNTER)) {
738 		ti_bandgap_read_counter(bgp, id, interval);
739 		goto exit;
740 	}
741 
742 	ti_bandgap_read_counter_delay(bgp, id, interval);
743 exit:
744 	return ret;
745 }
746 
747 /**
748  * ti_bandgap_write_counter_delay() - set the counter_delay
749  * @bgp: pointer to bandgap instance
750  * @id: sensor id
751  * @interval: desired update interval in miliseconds
752  *
753  * Return: 0 on success or the proper error code
754  */
755 static int ti_bandgap_write_counter_delay(struct ti_bandgap *bgp, int id,
756 					  u32 interval)
757 {
758 	int rval;
759 
760 	switch (interval) {
761 	case 0: /* Immediate conversion */
762 		rval = 0x0;
763 		break;
764 	case 1: /* Conversion after ever 1ms */
765 		rval = 0x1;
766 		break;
767 	case 10: /* Conversion after ever 10ms */
768 		rval = 0x2;
769 		break;
770 	case 100: /* Conversion after ever 100ms */
771 		rval = 0x3;
772 		break;
773 	case 250: /* Conversion after ever 250ms */
774 		rval = 0x4;
775 		break;
776 	case 500: /* Conversion after ever 500ms */
777 		rval = 0x5;
778 		break;
779 	default:
780 		dev_warn(bgp->dev, "Delay %d ms is not supported\n", interval);
781 		return -EINVAL;
782 	}
783 
784 	spin_lock(&bgp->lock);
785 	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_counter_delay_mask, rval);
786 	spin_unlock(&bgp->lock);
787 
788 	return 0;
789 }
790 
791 /**
792  * ti_bandgap_write_counter() - set the bandgap sensor counter
793  * @bgp: pointer to bandgap instance
794  * @id: sensor id
795  * @interval: desired update interval in miliseconds
796  */
797 static void ti_bandgap_write_counter(struct ti_bandgap *bgp, int id,
798 				     u32 interval)
799 {
800 	interval = interval * bgp->clk_rate / 1000;
801 	spin_lock(&bgp->lock);
802 	RMW_BITS(bgp, id, bgap_counter, counter_mask, interval);
803 	spin_unlock(&bgp->lock);
804 }
805 
806 /**
807  * ti_bandgap_write_update_interval() - set the update interval
808  * @bgp: pointer to bandgap instance
809  * @id: sensor id
810  * @interval: desired update interval in miliseconds
811  *
812  * Return: 0 on success or the proper error code
813  */
814 int ti_bandgap_write_update_interval(struct ti_bandgap *bgp,
815 				     int id, u32 interval)
816 {
817 	int ret = ti_bandgap_validate(bgp, id);
818 	if (ret)
819 		goto exit;
820 
821 	if (!TI_BANDGAP_HAS(bgp, COUNTER) &&
822 	    !TI_BANDGAP_HAS(bgp, COUNTER_DELAY)) {
823 		ret = -ENOTSUPP;
824 		goto exit;
825 	}
826 
827 	if (TI_BANDGAP_HAS(bgp, COUNTER)) {
828 		ti_bandgap_write_counter(bgp, id, interval);
829 		goto exit;
830 	}
831 
832 	ret = ti_bandgap_write_counter_delay(bgp, id, interval);
833 exit:
834 	return ret;
835 }
836 
837 /**
838  * ti_bandgap_read_temperature() - report current temperature
839  * @bgp: pointer to bandgap instance
840  * @id: sensor id
841  * @temperature: resulting temperature
842  *
843  * Return: 0 on success or the proper error code
844  */
845 int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
846 				int *temperature)
847 {
848 	u32 temp;
849 	int ret;
850 
851 	ret = ti_bandgap_validate(bgp, id);
852 	if (ret)
853 		return ret;
854 
855 	spin_lock(&bgp->lock);
856 	temp = ti_bandgap_read_temp(bgp, id);
857 	spin_unlock(&bgp->lock);
858 
859 	ret |= ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
860 	if (ret)
861 		return -EIO;
862 
863 	*temperature = temp;
864 
865 	return 0;
866 }
867 
868 /**
869  * ti_bandgap_set_sensor_data() - helper function to store thermal
870  * framework related data.
871  * @bgp: pointer to bandgap instance
872  * @id: sensor id
873  * @data: thermal framework related data to be stored
874  *
875  * Return: 0 on success or the proper error code
876  */
877 int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data)
878 {
879 	int ret = ti_bandgap_validate(bgp, id);
880 	if (ret)
881 		return ret;
882 
883 	bgp->regval[id].data = data;
884 
885 	return 0;
886 }
887 
888 /**
889  * ti_bandgap_get_sensor_data() - helper function to get thermal
890  * framework related data.
891  * @bgp: pointer to bandgap instance
892  * @id: sensor id
893  *
894  * Return: data stored by set function with sensor id on success or NULL
895  */
896 void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id)
897 {
898 	int ret = ti_bandgap_validate(bgp, id);
899 	if (ret)
900 		return ERR_PTR(ret);
901 
902 	return bgp->regval[id].data;
903 }
904 
905 /***   Helper functions used during device initialization   ***/
906 
907 /**
908  * ti_bandgap_force_single_read() - executes 1 single ADC conversion
909  * @bgp: pointer to struct ti_bandgap
910  * @id: sensor id which it is desired to read 1 temperature
911  *
912  * Used to initialize the conversion state machine and set it to a valid
913  * state. Called during device initialization and context restore events.
914  *
915  * Return: 0
916  */
917 static int
918 ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
919 {
920 	u32 temp = 0, counter = 1000;
921 
922 	/* Select single conversion mode */
923 	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
924 		RMW_BITS(bgp, id, bgap_mode_ctrl, mode_ctrl_mask, 0);
925 
926 	/* Start of Conversion = 1 */
927 	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 1);
928 	/* Wait until DTEMP is updated */
929 	temp = ti_bandgap_read_temp(bgp, id);
930 
931 	while ((temp == 0) && --counter)
932 		temp = ti_bandgap_read_temp(bgp, id);
933 	/* REVISIT: Check correct condition for end of conversion */
934 
935 	/* Start of Conversion = 0 */
936 	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 0);
937 
938 	return 0;
939 }
940 
941 /**
942  * ti_bandgap_set_continous_mode() - One time enabling of continuous mode
943  * @bgp: pointer to struct ti_bandgap
944  *
945  * Call this function only if HAS(MODE_CONFIG) is set. As this driver may
946  * be used for junction temperature monitoring, it is desirable that the
947  * sensors are operational all the time, so that alerts are generated
948  * properly.
949  *
950  * Return: 0
951  */
952 static int ti_bandgap_set_continuous_mode(struct ti_bandgap *bgp)
953 {
954 	int i;
955 
956 	for (i = 0; i < bgp->conf->sensor_count; i++) {
957 		/* Perform a single read just before enabling continuous */
958 		ti_bandgap_force_single_read(bgp, i);
959 		RMW_BITS(bgp, i, bgap_mode_ctrl, mode_ctrl_mask, 1);
960 	}
961 
962 	return 0;
963 }
964 
965 /**
966  * ti_bandgap_get_trend() - To fetch the temperature trend of a sensor
967  * @bgp: pointer to struct ti_bandgap
968  * @id: id of the individual sensor
969  * @trend: Pointer to trend.
970  *
971  * This function needs to be called to fetch the temperature trend of a
972  * Particular sensor. The function computes the difference in temperature
973  * w.r.t time. For the bandgaps with built in history buffer the temperatures
974  * are read from the buffer and for those without the Buffer -ENOTSUPP is
975  * returned.
976  *
977  * Return: 0 if no error, else return corresponding error. If no
978  *		error then the trend value is passed on to trend parameter
979  */
980 int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend)
981 {
982 	struct temp_sensor_registers *tsr;
983 	u32 temp1, temp2, reg1, reg2;
984 	int t1, t2, interval, ret = 0;
985 
986 	ret = ti_bandgap_validate(bgp, id);
987 	if (ret)
988 		goto exit;
989 
990 	if (!TI_BANDGAP_HAS(bgp, HISTORY_BUFFER) ||
991 	    !TI_BANDGAP_HAS(bgp, FREEZE_BIT)) {
992 		ret = -ENOTSUPP;
993 		goto exit;
994 	}
995 
996 	spin_lock(&bgp->lock);
997 
998 	tsr = bgp->conf->sensors[id].registers;
999 
1000 	/* Freeze and read the last 2 valid readings */
1001 	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 1);
1002 	reg1 = tsr->ctrl_dtemp_1;
1003 	reg2 = tsr->ctrl_dtemp_2;
1004 
1005 	/* read temperature from history buffer */
1006 	temp1 = ti_bandgap_readl(bgp, reg1);
1007 	temp1 &= tsr->bgap_dtemp_mask;
1008 
1009 	temp2 = ti_bandgap_readl(bgp, reg2);
1010 	temp2 &= tsr->bgap_dtemp_mask;
1011 
1012 	/* Convert from adc values to mCelsius temperature */
1013 	ret = ti_bandgap_adc_to_mcelsius(bgp, temp1, &t1);
1014 	if (ret)
1015 		goto unfreeze;
1016 
1017 	ret = ti_bandgap_adc_to_mcelsius(bgp, temp2, &t2);
1018 	if (ret)
1019 		goto unfreeze;
1020 
1021 	/* Fetch the update interval */
1022 	ret = ti_bandgap_read_update_interval(bgp, id, &interval);
1023 	if (ret)
1024 		goto unfreeze;
1025 
1026 	/* Set the interval to 1 ms if bandgap counter delay is not set */
1027 	if (interval == 0)
1028 		interval = 1;
1029 
1030 	*trend = (t1 - t2) / interval;
1031 
1032 	dev_dbg(bgp->dev, "The temperatures are t1 = %d and t2 = %d and trend =%d\n",
1033 		t1, t2, *trend);
1034 
1035 unfreeze:
1036 	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 0);
1037 	spin_unlock(&bgp->lock);
1038 exit:
1039 	return ret;
1040 }
1041 
1042 /**
1043  * ti_bandgap_tshut_init() - setup and initialize tshut handling
1044  * @bgp: pointer to struct ti_bandgap
1045  * @pdev: pointer to device struct platform_device
1046  *
1047  * Call this function only in case the bandgap features HAS(TSHUT).
1048  * In this case, the driver needs to handle the TSHUT signal as an IRQ.
1049  * The IRQ is wired as a GPIO, and for this purpose, it is required
1050  * to specify which GPIO line is used. TSHUT IRQ is fired anytime
1051  * one of the bandgap sensors violates the TSHUT high/hot threshold.
1052  * And in that case, the system must go off.
1053  *
1054  * Return: 0 if no error, else error status
1055  */
1056 static int ti_bandgap_tshut_init(struct ti_bandgap *bgp,
1057 				 struct platform_device *pdev)
1058 {
1059 	int gpio_nr = bgp->tshut_gpio;
1060 	int status;
1061 
1062 	/* Request for gpio_86 line */
1063 	status = gpio_request(gpio_nr, "tshut");
1064 	if (status < 0) {
1065 		dev_err(bgp->dev, "Could not request for TSHUT GPIO:%i\n", 86);
1066 		return status;
1067 	}
1068 	status = gpio_direction_input(gpio_nr);
1069 	if (status) {
1070 		dev_err(bgp->dev, "Cannot set input TSHUT GPIO %d\n", gpio_nr);
1071 		return status;
1072 	}
1073 
1074 	status = request_irq(gpio_to_irq(gpio_nr), ti_bandgap_tshut_irq_handler,
1075 			     IRQF_TRIGGER_RISING, "tshut", NULL);
1076 	if (status) {
1077 		gpio_free(gpio_nr);
1078 		dev_err(bgp->dev, "request irq failed for TSHUT");
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 /**
1085  * ti_bandgap_alert_init() - setup and initialize talert handling
1086  * @bgp: pointer to struct ti_bandgap
1087  * @pdev: pointer to device struct platform_device
1088  *
1089  * Call this function only in case the bandgap features HAS(TALERT).
1090  * In this case, the driver needs to handle the TALERT signals as an IRQs.
1091  * TALERT is a normal IRQ and it is fired any time thresholds (hot or cold)
1092  * are violated. In these situation, the driver must reprogram the thresholds,
1093  * accordingly to specified policy.
1094  *
1095  * Return: 0 if no error, else return corresponding error.
1096  */
1097 static int ti_bandgap_talert_init(struct ti_bandgap *bgp,
1098 				  struct platform_device *pdev)
1099 {
1100 	int ret;
1101 
1102 	bgp->irq = platform_get_irq(pdev, 0);
1103 	if (bgp->irq < 0) {
1104 		dev_err(&pdev->dev, "get_irq failed\n");
1105 		return bgp->irq;
1106 	}
1107 	ret = request_threaded_irq(bgp->irq, NULL,
1108 				   ti_bandgap_talert_irq_handler,
1109 				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
1110 				   "talert", bgp);
1111 	if (ret) {
1112 		dev_err(&pdev->dev, "Request threaded irq failed.\n");
1113 		return ret;
1114 	}
1115 
1116 	return 0;
1117 }
1118 
1119 static const struct of_device_id of_ti_bandgap_match[];
1120 /**
1121  * ti_bandgap_build() - parse DT and setup a struct ti_bandgap
1122  * @pdev: pointer to device struct platform_device
1123  *
1124  * Used to read the device tree properties accordingly to the bandgap
1125  * matching version. Based on bandgap version and its capabilities it
1126  * will build a struct ti_bandgap out of the required DT entries.
1127  *
1128  * Return: valid bandgap structure if successful, else returns ERR_PTR
1129  * return value must be verified with IS_ERR.
1130  */
1131 static struct ti_bandgap *ti_bandgap_build(struct platform_device *pdev)
1132 {
1133 	struct device_node *node = pdev->dev.of_node;
1134 	const struct of_device_id *of_id;
1135 	struct ti_bandgap *bgp;
1136 	struct resource *res;
1137 	int i;
1138 
1139 	/* just for the sake */
1140 	if (!node) {
1141 		dev_err(&pdev->dev, "no platform information available\n");
1142 		return ERR_PTR(-EINVAL);
1143 	}
1144 
1145 	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
1146 	if (!bgp) {
1147 		dev_err(&pdev->dev, "Unable to allocate mem for driver ref\n");
1148 		return ERR_PTR(-ENOMEM);
1149 	}
1150 
1151 	of_id = of_match_device(of_ti_bandgap_match, &pdev->dev);
1152 	if (of_id)
1153 		bgp->conf = of_id->data;
1154 
1155 	/* register shadow for context save and restore */
1156 	bgp->regval = devm_kzalloc(&pdev->dev, sizeof(*bgp->regval) *
1157 				   bgp->conf->sensor_count, GFP_KERNEL);
1158 	if (!bgp->regval) {
1159 		dev_err(&pdev->dev, "Unable to allocate mem for driver ref\n");
1160 		return ERR_PTR(-ENOMEM);
1161 	}
1162 
1163 	i = 0;
1164 	do {
1165 		void __iomem *chunk;
1166 
1167 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
1168 		if (!res)
1169 			break;
1170 		chunk = devm_ioremap_resource(&pdev->dev, res);
1171 		if (i == 0)
1172 			bgp->base = chunk;
1173 		if (IS_ERR(chunk))
1174 			return ERR_CAST(chunk);
1175 
1176 		i++;
1177 	} while (res);
1178 
1179 	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
1180 		bgp->tshut_gpio = of_get_gpio(node, 0);
1181 		if (!gpio_is_valid(bgp->tshut_gpio)) {
1182 			dev_err(&pdev->dev, "invalid gpio for tshut (%d)\n",
1183 				bgp->tshut_gpio);
1184 			return ERR_PTR(-EINVAL);
1185 		}
1186 	}
1187 
1188 	return bgp;
1189 }
1190 
1191 /***   Device driver call backs   ***/
1192 
1193 static
1194 int ti_bandgap_probe(struct platform_device *pdev)
1195 {
1196 	struct ti_bandgap *bgp;
1197 	int clk_rate, ret = 0, i;
1198 
1199 	bgp = ti_bandgap_build(pdev);
1200 	if (IS_ERR(bgp)) {
1201 		dev_err(&pdev->dev, "failed to fetch platform data\n");
1202 		return PTR_ERR(bgp);
1203 	}
1204 	bgp->dev = &pdev->dev;
1205 
1206 	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
1207 		ret = ti_bandgap_tshut_init(bgp, pdev);
1208 		if (ret) {
1209 			dev_err(&pdev->dev,
1210 				"failed to initialize system tshut IRQ\n");
1211 			return ret;
1212 		}
1213 	}
1214 
1215 	bgp->fclock = clk_get(NULL, bgp->conf->fclock_name);
1216 	ret = IS_ERR(bgp->fclock);
1217 	if (ret) {
1218 		dev_err(&pdev->dev, "failed to request fclock reference\n");
1219 		ret = PTR_ERR(bgp->fclock);
1220 		goto free_irqs;
1221 	}
1222 
1223 	bgp->div_clk = clk_get(NULL,  bgp->conf->div_ck_name);
1224 	ret = IS_ERR(bgp->div_clk);
1225 	if (ret) {
1226 		dev_err(&pdev->dev,
1227 			"failed to request div_ts_ck clock ref\n");
1228 		ret = PTR_ERR(bgp->div_clk);
1229 		goto free_irqs;
1230 	}
1231 
1232 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1233 		struct temp_sensor_registers *tsr;
1234 		u32 val;
1235 
1236 		tsr = bgp->conf->sensors[i].registers;
1237 		/*
1238 		 * check if the efuse has a non-zero value if not
1239 		 * it is an untrimmed sample and the temperatures
1240 		 * may not be accurate
1241 		 */
1242 		val = ti_bandgap_readl(bgp, tsr->bgap_efuse);
1243 		if (ret || !val)
1244 			dev_info(&pdev->dev,
1245 				 "Non-trimmed BGAP, Temp not accurate\n");
1246 	}
1247 
1248 	clk_rate = clk_round_rate(bgp->div_clk,
1249 				  bgp->conf->sensors[0].ts_data->max_freq);
1250 	if (clk_rate < bgp->conf->sensors[0].ts_data->min_freq ||
1251 	    clk_rate <= 0) {
1252 		ret = -ENODEV;
1253 		dev_err(&pdev->dev, "wrong clock rate (%d)\n", clk_rate);
1254 		goto put_clks;
1255 	}
1256 
1257 	ret = clk_set_rate(bgp->div_clk, clk_rate);
1258 	if (ret)
1259 		dev_err(&pdev->dev, "Cannot re-set clock rate. Continuing\n");
1260 
1261 	bgp->clk_rate = clk_rate;
1262 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1263 		clk_prepare_enable(bgp->fclock);
1264 
1265 
1266 	spin_lock_init(&bgp->lock);
1267 	bgp->dev = &pdev->dev;
1268 	platform_set_drvdata(pdev, bgp);
1269 
1270 	ti_bandgap_power(bgp, true);
1271 
1272 	/* Set default counter to 1 for now */
1273 	if (TI_BANDGAP_HAS(bgp, COUNTER))
1274 		for (i = 0; i < bgp->conf->sensor_count; i++)
1275 			RMW_BITS(bgp, i, bgap_counter, counter_mask, 1);
1276 
1277 	/* Set default thresholds for alert and shutdown */
1278 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1279 		struct temp_sensor_data *ts_data;
1280 
1281 		ts_data = bgp->conf->sensors[i].ts_data;
1282 
1283 		if (TI_BANDGAP_HAS(bgp, TALERT)) {
1284 			/* Set initial Talert thresholds */
1285 			RMW_BITS(bgp, i, bgap_threshold,
1286 				 threshold_tcold_mask, ts_data->t_cold);
1287 			RMW_BITS(bgp, i, bgap_threshold,
1288 				 threshold_thot_mask, ts_data->t_hot);
1289 			/* Enable the alert events */
1290 			RMW_BITS(bgp, i, bgap_mask_ctrl, mask_hot_mask, 1);
1291 			RMW_BITS(bgp, i, bgap_mask_ctrl, mask_cold_mask, 1);
1292 		}
1293 
1294 		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG)) {
1295 			/* Set initial Tshut thresholds */
1296 			RMW_BITS(bgp, i, tshut_threshold,
1297 				 tshut_hot_mask, ts_data->tshut_hot);
1298 			RMW_BITS(bgp, i, tshut_threshold,
1299 				 tshut_cold_mask, ts_data->tshut_cold);
1300 		}
1301 	}
1302 
1303 	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
1304 		ti_bandgap_set_continuous_mode(bgp);
1305 
1306 	/* Set .250 seconds time as default counter */
1307 	if (TI_BANDGAP_HAS(bgp, COUNTER))
1308 		for (i = 0; i < bgp->conf->sensor_count; i++)
1309 			RMW_BITS(bgp, i, bgap_counter, counter_mask,
1310 				 bgp->clk_rate / 4);
1311 
1312 	/* Every thing is good? Then expose the sensors */
1313 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1314 		char *domain;
1315 
1316 		if (bgp->conf->sensors[i].register_cooling) {
1317 			ret = bgp->conf->sensors[i].register_cooling(bgp, i);
1318 			if (ret)
1319 				goto remove_sensors;
1320 		}
1321 
1322 		if (bgp->conf->expose_sensor) {
1323 			domain = bgp->conf->sensors[i].domain;
1324 			ret = bgp->conf->expose_sensor(bgp, i, domain);
1325 			if (ret)
1326 				goto remove_last_cooling;
1327 		}
1328 	}
1329 
1330 	/*
1331 	 * Enable the Interrupts once everything is set. Otherwise irq handler
1332 	 * might be called as soon as it is enabled where as rest of framework
1333 	 * is still getting initialised.
1334 	 */
1335 	if (TI_BANDGAP_HAS(bgp, TALERT)) {
1336 		ret = ti_bandgap_talert_init(bgp, pdev);
1337 		if (ret) {
1338 			dev_err(&pdev->dev, "failed to initialize Talert IRQ\n");
1339 			i = bgp->conf->sensor_count;
1340 			goto disable_clk;
1341 		}
1342 	}
1343 
1344 	return 0;
1345 
1346 remove_last_cooling:
1347 	if (bgp->conf->sensors[i].unregister_cooling)
1348 		bgp->conf->sensors[i].unregister_cooling(bgp, i);
1349 remove_sensors:
1350 	for (i--; i >= 0; i--) {
1351 		if (bgp->conf->sensors[i].unregister_cooling)
1352 			bgp->conf->sensors[i].unregister_cooling(bgp, i);
1353 		if (bgp->conf->remove_sensor)
1354 			bgp->conf->remove_sensor(bgp, i);
1355 	}
1356 	ti_bandgap_power(bgp, false);
1357 disable_clk:
1358 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1359 		clk_disable_unprepare(bgp->fclock);
1360 put_clks:
1361 	clk_put(bgp->fclock);
1362 	clk_put(bgp->div_clk);
1363 free_irqs:
1364 	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
1365 		free_irq(gpio_to_irq(bgp->tshut_gpio), NULL);
1366 		gpio_free(bgp->tshut_gpio);
1367 	}
1368 
1369 	return ret;
1370 }
1371 
1372 static
1373 int ti_bandgap_remove(struct platform_device *pdev)
1374 {
1375 	struct ti_bandgap *bgp = platform_get_drvdata(pdev);
1376 	int i;
1377 
1378 	/* First thing is to remove sensor interfaces */
1379 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1380 		if (bgp->conf->sensors[i].unregister_cooling)
1381 			bgp->conf->sensors[i].unregister_cooling(bgp, i);
1382 
1383 		if (bgp->conf->remove_sensor)
1384 			bgp->conf->remove_sensor(bgp, i);
1385 	}
1386 
1387 	ti_bandgap_power(bgp, false);
1388 
1389 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1390 		clk_disable_unprepare(bgp->fclock);
1391 	clk_put(bgp->fclock);
1392 	clk_put(bgp->div_clk);
1393 
1394 	if (TI_BANDGAP_HAS(bgp, TALERT))
1395 		free_irq(bgp->irq, bgp);
1396 
1397 	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
1398 		free_irq(gpio_to_irq(bgp->tshut_gpio), NULL);
1399 		gpio_free(bgp->tshut_gpio);
1400 	}
1401 
1402 	return 0;
1403 }
1404 
1405 #ifdef CONFIG_PM_SLEEP
1406 static int ti_bandgap_save_ctxt(struct ti_bandgap *bgp)
1407 {
1408 	int i;
1409 
1410 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1411 		struct temp_sensor_registers *tsr;
1412 		struct temp_sensor_regval *rval;
1413 
1414 		rval = &bgp->regval[i];
1415 		tsr = bgp->conf->sensors[i].registers;
1416 
1417 		if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
1418 			rval->bg_mode_ctrl = ti_bandgap_readl(bgp,
1419 							tsr->bgap_mode_ctrl);
1420 		if (TI_BANDGAP_HAS(bgp, COUNTER))
1421 			rval->bg_counter = ti_bandgap_readl(bgp,
1422 							tsr->bgap_counter);
1423 		if (TI_BANDGAP_HAS(bgp, TALERT)) {
1424 			rval->bg_threshold = ti_bandgap_readl(bgp,
1425 							tsr->bgap_threshold);
1426 			rval->bg_ctrl = ti_bandgap_readl(bgp,
1427 						   tsr->bgap_mask_ctrl);
1428 		}
1429 
1430 		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG))
1431 			rval->tshut_threshold = ti_bandgap_readl(bgp,
1432 						   tsr->tshut_threshold);
1433 	}
1434 
1435 	return 0;
1436 }
1437 
1438 static int ti_bandgap_restore_ctxt(struct ti_bandgap *bgp)
1439 {
1440 	int i;
1441 
1442 	for (i = 0; i < bgp->conf->sensor_count; i++) {
1443 		struct temp_sensor_registers *tsr;
1444 		struct temp_sensor_regval *rval;
1445 		u32 val = 0;
1446 
1447 		rval = &bgp->regval[i];
1448 		tsr = bgp->conf->sensors[i].registers;
1449 
1450 		if (TI_BANDGAP_HAS(bgp, COUNTER))
1451 			val = ti_bandgap_readl(bgp, tsr->bgap_counter);
1452 
1453 		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG))
1454 			ti_bandgap_writel(bgp, rval->tshut_threshold,
1455 					  tsr->tshut_threshold);
1456 		/* Force immediate temperature measurement and update
1457 		 * of the DTEMP field
1458 		 */
1459 		ti_bandgap_force_single_read(bgp, i);
1460 
1461 		if (TI_BANDGAP_HAS(bgp, COUNTER))
1462 			ti_bandgap_writel(bgp, rval->bg_counter,
1463 					  tsr->bgap_counter);
1464 		if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
1465 			ti_bandgap_writel(bgp, rval->bg_mode_ctrl,
1466 					  tsr->bgap_mode_ctrl);
1467 		if (TI_BANDGAP_HAS(bgp, TALERT)) {
1468 			ti_bandgap_writel(bgp, rval->bg_threshold,
1469 					  tsr->bgap_threshold);
1470 			ti_bandgap_writel(bgp, rval->bg_ctrl,
1471 					  tsr->bgap_mask_ctrl);
1472 		}
1473 	}
1474 
1475 	return 0;
1476 }
1477 
1478 static int ti_bandgap_suspend(struct device *dev)
1479 {
1480 	struct ti_bandgap *bgp = dev_get_drvdata(dev);
1481 	int err;
1482 
1483 	err = ti_bandgap_save_ctxt(bgp);
1484 	ti_bandgap_power(bgp, false);
1485 
1486 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1487 		clk_disable_unprepare(bgp->fclock);
1488 
1489 	return err;
1490 }
1491 
1492 static int ti_bandgap_resume(struct device *dev)
1493 {
1494 	struct ti_bandgap *bgp = dev_get_drvdata(dev);
1495 
1496 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1497 		clk_prepare_enable(bgp->fclock);
1498 
1499 	ti_bandgap_power(bgp, true);
1500 
1501 	return ti_bandgap_restore_ctxt(bgp);
1502 }
1503 static SIMPLE_DEV_PM_OPS(ti_bandgap_dev_pm_ops, ti_bandgap_suspend,
1504 			 ti_bandgap_resume);
1505 
1506 #define DEV_PM_OPS	(&ti_bandgap_dev_pm_ops)
1507 #else
1508 #define DEV_PM_OPS	NULL
1509 #endif
1510 
1511 static const struct of_device_id of_ti_bandgap_match[] = {
1512 #ifdef CONFIG_OMAP4_THERMAL
1513 	{
1514 		.compatible = "ti,omap4430-bandgap",
1515 		.data = (void *)&omap4430_data,
1516 	},
1517 	{
1518 		.compatible = "ti,omap4460-bandgap",
1519 		.data = (void *)&omap4460_data,
1520 	},
1521 	{
1522 		.compatible = "ti,omap4470-bandgap",
1523 		.data = (void *)&omap4470_data,
1524 	},
1525 #endif
1526 #ifdef CONFIG_OMAP5_THERMAL
1527 	{
1528 		.compatible = "ti,omap5430-bandgap",
1529 		.data = (void *)&omap5430_data,
1530 	},
1531 #endif
1532 #ifdef CONFIG_DRA752_THERMAL
1533 	{
1534 		.compatible = "ti,dra752-bandgap",
1535 		.data = (void *)&dra752_data,
1536 	},
1537 #endif
1538 	/* Sentinel */
1539 	{ },
1540 };
1541 MODULE_DEVICE_TABLE(of, of_ti_bandgap_match);
1542 
1543 static struct platform_driver ti_bandgap_sensor_driver = {
1544 	.probe = ti_bandgap_probe,
1545 	.remove = ti_bandgap_remove,
1546 	.driver = {
1547 			.name = "ti-soc-thermal",
1548 			.pm = DEV_PM_OPS,
1549 			.of_match_table	= of_ti_bandgap_match,
1550 	},
1551 };
1552 
1553 module_platform_driver(ti_bandgap_sensor_driver);
1554 
1555 MODULE_DESCRIPTION("OMAP4+ bandgap temperature sensor driver");
1556 MODULE_LICENSE("GPL v2");
1557 MODULE_ALIAS("platform:ti-soc-thermal");
1558 MODULE_AUTHOR("Texas Instrument Inc.");
1559