1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI Bandgap temperature sensor driver
4 *
5 * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
6 * Author: J Keerthy <j-keerthy@ti.com>
7 * Author: Moiz Sonasath <m-sonasath@ti.com>
8 * Couple of fixes, DT and MFD adaptation:
9 *   Eduardo Valentin <eduardo.valentin@ti.com>
10 */
11
12#include <linux/clk.h>
13#include <linux/cpu_pm.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/export.h>
17#include <linux/gpio/consumer.h>
18#include <linux/init.h>
19#include <linux/interrupt.h>
20#include <linux/io.h>
21#include <linux/iopoll.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/of_device.h>
26#include <linux/of_irq.h>
27#include <linux/of_platform.h>
28#include <linux/platform_device.h>
29#include <linux/pm.h>
30#include <linux/pm_runtime.h>
31#include <linux/reboot.h>
32#include <linux/spinlock.h>
33#include <linux/sys_soc.h>
34#include <linux/types.h>
35
36#include "ti-bandgap.h"
37
38static int ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id);
39#ifdef CONFIG_PM_SLEEP
40static int bandgap_omap_cpu_notifier(struct notifier_block *nb,
41				  unsigned long cmd, void *v);
42#endif
43
44/***   Helper functions to access registers and their bitfields   ***/
45
46/**
47 * ti_bandgap_readl() - simple read helper function
48 * @bgp: pointer to ti_bandgap structure
49 * @reg: desired register (offset) to be read
50 *
51 * Helper function to read bandgap registers. It uses the io remapped area.
52 * Return: the register value.
53 */
54static u32 ti_bandgap_readl(struct ti_bandgap *bgp, u32 reg)
55{
56	return readl(bgp->base + reg);
57}
58
59/**
60 * ti_bandgap_writel() - simple write helper function
61 * @bgp: pointer to ti_bandgap structure
62 * @val: desired register value to be written
63 * @reg: desired register (offset) to be written
64 *
65 * Helper function to write bandgap registers. It uses the io remapped area.
66 */
67static void ti_bandgap_writel(struct ti_bandgap *bgp, u32 val, u32 reg)
68{
69	writel(val, bgp->base + reg);
70}
71
72/**
73 * DOC: macro to update bits.
74 *
75 * RMW_BITS() - used to read, modify and update bandgap bitfields.
76 *            The value passed will be shifted.
77 */
78#define RMW_BITS(bgp, id, reg, mask, val)			\
79do {								\
80	struct temp_sensor_registers *t;			\
81	u32 r;							\
82								\
83	t = bgp->conf->sensors[(id)].registers;		\
84	r = ti_bandgap_readl(bgp, t->reg);			\
85	r &= ~t->mask;						\
86	r |= (val) << __ffs(t->mask);				\
87	ti_bandgap_writel(bgp, r, t->reg);			\
88} while (0)
89
90/***   Basic helper functions   ***/
91
92/**
93 * ti_bandgap_power() - controls the power state of a bandgap device
94 * @bgp: pointer to ti_bandgap structure
95 * @on: desired power state (1 - on, 0 - off)
96 *
97 * Used to power on/off a bandgap device instance. Only used on those
98 * that features tempsoff bit.
99 *
100 * Return: 0 on success, -ENOTSUPP if tempsoff is not supported.
101 */
102static int ti_bandgap_power(struct ti_bandgap *bgp, bool on)
103{
104	int i;
105
106	if (!TI_BANDGAP_HAS(bgp, POWER_SWITCH))
107		return -ENOTSUPP;
108
109	for (i = 0; i < bgp->conf->sensor_count; i++)
110		/* active on 0 */
111		RMW_BITS(bgp, i, temp_sensor_ctrl, bgap_tempsoff_mask, !on);
112	return 0;
113}
114
115/**
116 * ti_errata814_bandgap_read_temp() - helper function to read dra7 sensor temperature
117 * @bgp: pointer to ti_bandgap structure
118 * @reg: desired register (offset) to be read
119 *
120 * Function to read dra7 bandgap sensor temperature. This is done separately
121 * so as to workaround the errata "Bandgap Temperature read Dtemp can be
122 * corrupted" - Errata ID: i814".
123 * Read accesses to registers listed below can be corrupted due to incorrect
124 * resynchronization between clock domains.
125 * Read access to registers below can be corrupted :
126 * CTRL_CORE_DTEMP_MPU/GPU/CORE/DSPEVE/IVA_n (n = 0 to 4)
127 * CTRL_CORE_TEMP_SENSOR_MPU/GPU/CORE/DSPEVE/IVA_n
128 *
129 * Return: the register value.
130 */
131static u32 ti_errata814_bandgap_read_temp(struct ti_bandgap *bgp,  u32 reg)
132{
133	u32 val1, val2;
134
135	val1 = ti_bandgap_readl(bgp, reg);
136	val2 = ti_bandgap_readl(bgp, reg);
137
138	/* If both times we read the same value then that is right */
139	if (val1 == val2)
140		return val1;
141
142	/* if val1 and val2 are different read it third time */
143	return ti_bandgap_readl(bgp, reg);
144}
145
146/**
147 * ti_bandgap_read_temp() - helper function to read sensor temperature
148 * @bgp: pointer to ti_bandgap structure
149 * @id: bandgap sensor id
150 *
151 * Function to concentrate the steps to read sensor temperature register.
152 * This function is desired because, depending on bandgap device version,
153 * it might be needed to freeze the bandgap state machine, before fetching
154 * the register value.
155 *
156 * Return: temperature in ADC values.
157 */
158static u32 ti_bandgap_read_temp(struct ti_bandgap *bgp, int id)
159{
160	struct temp_sensor_registers *tsr;
161	u32 temp, reg;
162
163	tsr = bgp->conf->sensors[id].registers;
164	reg = tsr->temp_sensor_ctrl;
165
166	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT)) {
167		RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 1);
168		/*
169		 * In case we cannot read from cur_dtemp / dtemp_0,
170		 * then we read from the last valid temp read
171		 */
172		reg = tsr->ctrl_dtemp_1;
173	}
174
175	/* read temperature */
176	if (TI_BANDGAP_HAS(bgp, ERRATA_814))
177		temp = ti_errata814_bandgap_read_temp(bgp, reg);
178	else
179		temp = ti_bandgap_readl(bgp, reg);
180
181	temp &= tsr->bgap_dtemp_mask;
182
183	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT))
184		RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 0);
185
186	return temp;
187}
188
189/***   IRQ handlers   ***/
190
191/**
192 * ti_bandgap_talert_irq_handler() - handles Temperature alert IRQs
193 * @irq: IRQ number
194 * @data: private data (struct ti_bandgap *)
195 *
196 * This is the Talert handler. Use it only if bandgap device features
197 * HAS(TALERT). This handler goes over all sensors and checks their
198 * conditions and acts accordingly. In case there are events pending,
199 * it will reset the event mask to wait for the opposite event (next event).
200 * Every time there is a new event, it will be reported to thermal layer.
201 *
202 * Return: IRQ_HANDLED
203 */
204static irqreturn_t ti_bandgap_talert_irq_handler(int irq, void *data)
205{
206	struct ti_bandgap *bgp = data;
207	struct temp_sensor_registers *tsr;
208	u32 t_hot = 0, t_cold = 0, ctrl;
209	int i;
210
211	spin_lock(&bgp->lock);
212	for (i = 0; i < bgp->conf->sensor_count; i++) {
213		tsr = bgp->conf->sensors[i].registers;
214		ctrl = ti_bandgap_readl(bgp, tsr->bgap_status);
215
216		/* Read the status of t_hot */
217		t_hot = ctrl & tsr->status_hot_mask;
218
219		/* Read the status of t_cold */
220		t_cold = ctrl & tsr->status_cold_mask;
221
222		if (!t_cold && !t_hot)
223			continue;
224
225		ctrl = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
226		/*
227		 * One TALERT interrupt: Two sources
228		 * If the interrupt is due to t_hot then mask t_hot and
229		 * unmask t_cold else mask t_cold and unmask t_hot
230		 */
231		if (t_hot) {
232			ctrl &= ~tsr->mask_hot_mask;
233			ctrl |= tsr->mask_cold_mask;
234		} else if (t_cold) {
235			ctrl &= ~tsr->mask_cold_mask;
236			ctrl |= tsr->mask_hot_mask;
237		}
238
239		ti_bandgap_writel(bgp, ctrl, tsr->bgap_mask_ctrl);
240
241		dev_dbg(bgp->dev,
242			"%s: IRQ from %s sensor: hotevent %d coldevent %d\n",
243			__func__, bgp->conf->sensors[i].domain,
244			t_hot, t_cold);
245
246		/* report temperature to whom may concern */
247		if (bgp->conf->report_temperature)
248			bgp->conf->report_temperature(bgp, i);
249	}
250	spin_unlock(&bgp->lock);
251
252	return IRQ_HANDLED;
253}
254
255/**
256 * ti_bandgap_tshut_irq_handler() - handles Temperature shutdown signal
257 * @irq: IRQ number
258 * @data: private data (unused)
259 *
260 * This is the Tshut handler. Use it only if bandgap device features
261 * HAS(TSHUT). If any sensor fires the Tshut signal, we simply shutdown
262 * the system.
263 *
264 * Return: IRQ_HANDLED
265 */
266static irqreturn_t ti_bandgap_tshut_irq_handler(int irq, void *data)
267{
268	pr_emerg("%s: TSHUT temperature reached. Needs shut down...\n",
269		 __func__);
270
271	orderly_poweroff(true);
272
273	return IRQ_HANDLED;
274}
275
276/***   Helper functions which manipulate conversion ADC <-> mi Celsius   ***/
277
278/**
279 * ti_bandgap_adc_to_mcelsius() - converts an ADC value to mCelsius scale
280 * @bgp: struct ti_bandgap pointer
281 * @adc_val: value in ADC representation
282 * @t: address where to write the resulting temperature in mCelsius
283 *
284 * Simple conversion from ADC representation to mCelsius. In case the ADC value
285 * is out of the ADC conv table range, it returns -ERANGE, 0 on success.
286 * The conversion table is indexed by the ADC values.
287 *
288 * Return: 0 if conversion was successful, else -ERANGE in case the @adc_val
289 * argument is out of the ADC conv table range.
290 */
291static
292int ti_bandgap_adc_to_mcelsius(struct ti_bandgap *bgp, int adc_val, int *t)
293{
294	const struct ti_bandgap_data *conf = bgp->conf;
295
296	/* look up for temperature in the table and return the temperature */
297	if (adc_val < conf->adc_start_val || adc_val > conf->adc_end_val)
298		return -ERANGE;
299
300	*t = bgp->conf->conv_table[adc_val - conf->adc_start_val];
301	return 0;
302}
303
304/**
305 * ti_bandgap_validate() - helper to check the sanity of a struct ti_bandgap
306 * @bgp: struct ti_bandgap pointer
307 * @id: bandgap sensor id
308 *
309 * Checks if the bandgap pointer is valid and if the sensor id is also
310 * applicable.
311 *
312 * Return: 0 if no errors, -EINVAL for invalid @bgp pointer or -ERANGE if
313 * @id cannot index @bgp sensors.
314 */
315static inline int ti_bandgap_validate(struct ti_bandgap *bgp, int id)
316{
317	if (IS_ERR_OR_NULL(bgp)) {
318		pr_err("%s: invalid bandgap pointer\n", __func__);
319		return -EINVAL;
320	}
321
322	if ((id < 0) || (id >= bgp->conf->sensor_count)) {
323		dev_err(bgp->dev, "%s: sensor id out of range (%d)\n",
324			__func__, id);
325		return -ERANGE;
326	}
327
328	return 0;
329}
330
331/**
332 * ti_bandgap_read_counter() - read the sensor counter
333 * @bgp: pointer to bandgap instance
334 * @id: sensor id
335 * @interval: resulting update interval in miliseconds
336 */
337static void ti_bandgap_read_counter(struct ti_bandgap *bgp, int id,
338				    int *interval)
339{
340	struct temp_sensor_registers *tsr;
341	int time;
342
343	tsr = bgp->conf->sensors[id].registers;
344	time = ti_bandgap_readl(bgp, tsr->bgap_counter);
345	time = (time & tsr->counter_mask) >>
346					__ffs(tsr->counter_mask);
347	time = time * 1000 / bgp->clk_rate;
348	*interval = time;
349}
350
351/**
352 * ti_bandgap_read_counter_delay() - read the sensor counter delay
353 * @bgp: pointer to bandgap instance
354 * @id: sensor id
355 * @interval: resulting update interval in miliseconds
356 */
357static void ti_bandgap_read_counter_delay(struct ti_bandgap *bgp, int id,
358					  int *interval)
359{
360	struct temp_sensor_registers *tsr;
361	int reg_val;
362
363	tsr = bgp->conf->sensors[id].registers;
364
365	reg_val = ti_bandgap_readl(bgp, tsr->bgap_mask_ctrl);
366	reg_val = (reg_val & tsr->mask_counter_delay_mask) >>
367				__ffs(tsr->mask_counter_delay_mask);
368	switch (reg_val) {
369	case 0:
370		*interval = 0;
371		break;
372	case 1:
373		*interval = 1;
374		break;
375	case 2:
376		*interval = 10;
377		break;
378	case 3:
379		*interval = 100;
380		break;
381	case 4:
382		*interval = 250;
383		break;
384	case 5:
385		*interval = 500;
386		break;
387	default:
388		dev_warn(bgp->dev, "Wrong counter delay value read from register %X",
389			 reg_val);
390	}
391}
392
393/**
394 * ti_bandgap_read_update_interval() - read the sensor update interval
395 * @bgp: pointer to bandgap instance
396 * @id: sensor id
397 * @interval: resulting update interval in miliseconds
398 *
399 * Return: 0 on success or the proper error code
400 */
401int ti_bandgap_read_update_interval(struct ti_bandgap *bgp, int id,
402				    int *interval)
403{
404	int ret = 0;
405
406	ret = ti_bandgap_validate(bgp, id);
407	if (ret)
408		goto exit;
409
410	if (!TI_BANDGAP_HAS(bgp, COUNTER) &&
411	    !TI_BANDGAP_HAS(bgp, COUNTER_DELAY)) {
412		ret = -ENOTSUPP;
413		goto exit;
414	}
415
416	if (TI_BANDGAP_HAS(bgp, COUNTER)) {
417		ti_bandgap_read_counter(bgp, id, interval);
418		goto exit;
419	}
420
421	ti_bandgap_read_counter_delay(bgp, id, interval);
422exit:
423	return ret;
424}
425
426/**
427 * ti_bandgap_write_counter_delay() - set the counter_delay
428 * @bgp: pointer to bandgap instance
429 * @id: sensor id
430 * @interval: desired update interval in miliseconds
431 *
432 * Return: 0 on success or the proper error code
433 */
434static int ti_bandgap_write_counter_delay(struct ti_bandgap *bgp, int id,
435					  u32 interval)
436{
437	int rval;
438
439	switch (interval) {
440	case 0: /* Immediate conversion */
441		rval = 0x0;
442		break;
443	case 1: /* Conversion after ever 1ms */
444		rval = 0x1;
445		break;
446	case 10: /* Conversion after ever 10ms */
447		rval = 0x2;
448		break;
449	case 100: /* Conversion after ever 100ms */
450		rval = 0x3;
451		break;
452	case 250: /* Conversion after ever 250ms */
453		rval = 0x4;
454		break;
455	case 500: /* Conversion after ever 500ms */
456		rval = 0x5;
457		break;
458	default:
459		dev_warn(bgp->dev, "Delay %d ms is not supported\n", interval);
460		return -EINVAL;
461	}
462
463	spin_lock(&bgp->lock);
464	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_counter_delay_mask, rval);
465	spin_unlock(&bgp->lock);
466
467	return 0;
468}
469
470/**
471 * ti_bandgap_write_counter() - set the bandgap sensor counter
472 * @bgp: pointer to bandgap instance
473 * @id: sensor id
474 * @interval: desired update interval in miliseconds
475 */
476static void ti_bandgap_write_counter(struct ti_bandgap *bgp, int id,
477				     u32 interval)
478{
479	interval = interval * bgp->clk_rate / 1000;
480	spin_lock(&bgp->lock);
481	RMW_BITS(bgp, id, bgap_counter, counter_mask, interval);
482	spin_unlock(&bgp->lock);
483}
484
485/**
486 * ti_bandgap_write_update_interval() - set the update interval
487 * @bgp: pointer to bandgap instance
488 * @id: sensor id
489 * @interval: desired update interval in miliseconds
490 *
491 * Return: 0 on success or the proper error code
492 */
493int ti_bandgap_write_update_interval(struct ti_bandgap *bgp,
494				     int id, u32 interval)
495{
496	int ret = ti_bandgap_validate(bgp, id);
497	if (ret)
498		goto exit;
499
500	if (!TI_BANDGAP_HAS(bgp, COUNTER) &&
501	    !TI_BANDGAP_HAS(bgp, COUNTER_DELAY)) {
502		ret = -ENOTSUPP;
503		goto exit;
504	}
505
506	if (TI_BANDGAP_HAS(bgp, COUNTER)) {
507		ti_bandgap_write_counter(bgp, id, interval);
508		goto exit;
509	}
510
511	ret = ti_bandgap_write_counter_delay(bgp, id, interval);
512exit:
513	return ret;
514}
515
516/**
517 * ti_bandgap_read_temperature() - report current temperature
518 * @bgp: pointer to bandgap instance
519 * @id: sensor id
520 * @temperature: resulting temperature
521 *
522 * Return: 0 on success or the proper error code
523 */
524int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
525				int *temperature)
526{
527	u32 temp;
528	int ret;
529
530	ret = ti_bandgap_validate(bgp, id);
531	if (ret)
532		return ret;
533
534	if (!TI_BANDGAP_HAS(bgp, MODE_CONFIG)) {
535		ret = ti_bandgap_force_single_read(bgp, id);
536		if (ret)
537			return ret;
538	}
539
540	spin_lock(&bgp->lock);
541	temp = ti_bandgap_read_temp(bgp, id);
542	spin_unlock(&bgp->lock);
543
544	ret = ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
545	if (ret)
546		return -EIO;
547
548	*temperature = temp;
549
550	return 0;
551}
552
553/**
554 * ti_bandgap_set_sensor_data() - helper function to store thermal
555 * framework related data.
556 * @bgp: pointer to bandgap instance
557 * @id: sensor id
558 * @data: thermal framework related data to be stored
559 *
560 * Return: 0 on success or the proper error code
561 */
562int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data)
563{
564	int ret = ti_bandgap_validate(bgp, id);
565	if (ret)
566		return ret;
567
568	bgp->regval[id].data = data;
569
570	return 0;
571}
572
573/**
574 * ti_bandgap_get_sensor_data() - helper function to get thermal
575 * framework related data.
576 * @bgp: pointer to bandgap instance
577 * @id: sensor id
578 *
579 * Return: data stored by set function with sensor id on success or NULL
580 */
581void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id)
582{
583	int ret = ti_bandgap_validate(bgp, id);
584	if (ret)
585		return ERR_PTR(ret);
586
587	return bgp->regval[id].data;
588}
589
590/***   Helper functions used during device initialization   ***/
591
592/**
593 * ti_bandgap_force_single_read() - executes 1 single ADC conversion
594 * @bgp: pointer to struct ti_bandgap
595 * @id: sensor id which it is desired to read 1 temperature
596 *
597 * Used to initialize the conversion state machine and set it to a valid
598 * state. Called during device initialization and context restore events.
599 *
600 * Return: 0
601 */
602static int
603ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
604{
605	struct temp_sensor_registers *tsr = bgp->conf->sensors[id].registers;
606	void __iomem *temp_sensor_ctrl = bgp->base + tsr->temp_sensor_ctrl;
607	int error;
608	u32 val;
609
610	/* Select continuous or single conversion mode */
611	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG)) {
612		if (TI_BANDGAP_HAS(bgp, CONT_MODE_ONLY))
613			RMW_BITS(bgp, id, bgap_mode_ctrl, mode_ctrl_mask, 1);
614		else
615			RMW_BITS(bgp, id, bgap_mode_ctrl, mode_ctrl_mask, 0);
616	}
617
618	/* Set Start of Conversion if available */
619	if (tsr->bgap_soc_mask) {
620		RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 1);
621
622		/* Wait for EOCZ going up */
623		error = readl_poll_timeout_atomic(temp_sensor_ctrl, val,
624						  val & tsr->bgap_eocz_mask,
625						  1, 1000);
626		if (error)
627			dev_warn(bgp->dev, "eocz timed out waiting high\n");
628
629		/* Clear Start of Conversion if available */
630		RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 0);
631	}
632
633	/* Wait for EOCZ going down, always needed even if no bgap_soc_mask */
634	error = readl_poll_timeout_atomic(temp_sensor_ctrl, val,
635					  !(val & tsr->bgap_eocz_mask),
636					  1, 1500);
637	if (error)
638		dev_warn(bgp->dev, "eocz timed out waiting low\n");
639
640	return 0;
641}
642
643/**
644 * ti_bandgap_set_continuous_mode() - One time enabling of continuous mode
645 * @bgp: pointer to struct ti_bandgap
646 *
647 * Call this function only if HAS(MODE_CONFIG) is set. As this driver may
648 * be used for junction temperature monitoring, it is desirable that the
649 * sensors are operational all the time, so that alerts are generated
650 * properly.
651 *
652 * Return: 0
653 */
654static int ti_bandgap_set_continuous_mode(struct ti_bandgap *bgp)
655{
656	int i;
657
658	for (i = 0; i < bgp->conf->sensor_count; i++) {
659		/* Perform a single read just before enabling continuous */
660		ti_bandgap_force_single_read(bgp, i);
661		RMW_BITS(bgp, i, bgap_mode_ctrl, mode_ctrl_mask, 1);
662	}
663
664	return 0;
665}
666
667/**
668 * ti_bandgap_get_trend() - To fetch the temperature trend of a sensor
669 * @bgp: pointer to struct ti_bandgap
670 * @id: id of the individual sensor
671 * @trend: Pointer to trend.
672 *
673 * This function needs to be called to fetch the temperature trend of a
674 * Particular sensor. The function computes the difference in temperature
675 * w.r.t time. For the bandgaps with built in history buffer the temperatures
676 * are read from the buffer and for those without the Buffer -ENOTSUPP is
677 * returned.
678 *
679 * Return: 0 if no error, else return corresponding error. If no
680 *		error then the trend value is passed on to trend parameter
681 */
682int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend)
683{
684	struct temp_sensor_registers *tsr;
685	u32 temp1, temp2, reg1, reg2;
686	int t1, t2, interval, ret = 0;
687
688	ret = ti_bandgap_validate(bgp, id);
689	if (ret)
690		goto exit;
691
692	if (!TI_BANDGAP_HAS(bgp, HISTORY_BUFFER) ||
693	    !TI_BANDGAP_HAS(bgp, FREEZE_BIT)) {
694		ret = -ENOTSUPP;
695		goto exit;
696	}
697
698	spin_lock(&bgp->lock);
699
700	tsr = bgp->conf->sensors[id].registers;
701
702	/* Freeze and read the last 2 valid readings */
703	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 1);
704	reg1 = tsr->ctrl_dtemp_1;
705	reg2 = tsr->ctrl_dtemp_2;
706
707	/* read temperature from history buffer */
708	temp1 = ti_bandgap_readl(bgp, reg1);
709	temp1 &= tsr->bgap_dtemp_mask;
710
711	temp2 = ti_bandgap_readl(bgp, reg2);
712	temp2 &= tsr->bgap_dtemp_mask;
713
714	/* Convert from adc values to mCelsius temperature */
715	ret = ti_bandgap_adc_to_mcelsius(bgp, temp1, &t1);
716	if (ret)
717		goto unfreeze;
718
719	ret = ti_bandgap_adc_to_mcelsius(bgp, temp2, &t2);
720	if (ret)
721		goto unfreeze;
722
723	/* Fetch the update interval */
724	ret = ti_bandgap_read_update_interval(bgp, id, &interval);
725	if (ret)
726		goto unfreeze;
727
728	/* Set the interval to 1 ms if bandgap counter delay is not set */
729	if (interval == 0)
730		interval = 1;
731
732	*trend = (t1 - t2) / interval;
733
734	dev_dbg(bgp->dev, "The temperatures are t1 = %d and t2 = %d and trend =%d\n",
735		t1, t2, *trend);
736
737unfreeze:
738	RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 0);
739	spin_unlock(&bgp->lock);
740exit:
741	return ret;
742}
743
744/**
745 * ti_bandgap_tshut_init() - setup and initialize tshut handling
746 * @bgp: pointer to struct ti_bandgap
747 * @pdev: pointer to device struct platform_device
748 *
749 * Call this function only in case the bandgap features HAS(TSHUT).
750 * In this case, the driver needs to handle the TSHUT signal as an IRQ.
751 * The IRQ is wired as a GPIO, and for this purpose, it is required
752 * to specify which GPIO line is used. TSHUT IRQ is fired anytime
753 * one of the bandgap sensors violates the TSHUT high/hot threshold.
754 * And in that case, the system must go off.
755 *
756 * Return: 0 if no error, else error status
757 */
758static int ti_bandgap_tshut_init(struct ti_bandgap *bgp,
759				 struct platform_device *pdev)
760{
761	int status;
762
763	status = request_irq(gpiod_to_irq(bgp->tshut_gpiod),
764			     ti_bandgap_tshut_irq_handler,
765			     IRQF_TRIGGER_RISING, "tshut", NULL);
766	if (status)
767		dev_err(bgp->dev, "request irq failed for TSHUT");
768
769	return 0;
770}
771
772/**
773 * ti_bandgap_talert_init() - setup and initialize talert handling
774 * @bgp: pointer to struct ti_bandgap
775 * @pdev: pointer to device struct platform_device
776 *
777 * Call this function only in case the bandgap features HAS(TALERT).
778 * In this case, the driver needs to handle the TALERT signals as an IRQs.
779 * TALERT is a normal IRQ and it is fired any time thresholds (hot or cold)
780 * are violated. In these situation, the driver must reprogram the thresholds,
781 * accordingly to specified policy.
782 *
783 * Return: 0 if no error, else return corresponding error.
784 */
785static int ti_bandgap_talert_init(struct ti_bandgap *bgp,
786				  struct platform_device *pdev)
787{
788	int ret;
789
790	bgp->irq = platform_get_irq(pdev, 0);
791	if (bgp->irq < 0)
792		return bgp->irq;
793
794	ret = request_threaded_irq(bgp->irq, NULL,
795				   ti_bandgap_talert_irq_handler,
796				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
797				   "talert", bgp);
798	if (ret) {
799		dev_err(&pdev->dev, "Request threaded irq failed.\n");
800		return ret;
801	}
802
803	return 0;
804}
805
806static const struct of_device_id of_ti_bandgap_match[];
807/**
808 * ti_bandgap_build() - parse DT and setup a struct ti_bandgap
809 * @pdev: pointer to device struct platform_device
810 *
811 * Used to read the device tree properties accordingly to the bandgap
812 * matching version. Based on bandgap version and its capabilities it
813 * will build a struct ti_bandgap out of the required DT entries.
814 *
815 * Return: valid bandgap structure if successful, else returns ERR_PTR
816 * return value must be verified with IS_ERR.
817 */
818static struct ti_bandgap *ti_bandgap_build(struct platform_device *pdev)
819{
820	struct device_node *node = pdev->dev.of_node;
821	const struct of_device_id *of_id;
822	struct ti_bandgap *bgp;
823	struct resource *res;
824	int i;
825
826	/* just for the sake */
827	if (!node) {
828		dev_err(&pdev->dev, "no platform information available\n");
829		return ERR_PTR(-EINVAL);
830	}
831
832	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
833	if (!bgp)
834		return ERR_PTR(-ENOMEM);
835
836	of_id = of_match_device(of_ti_bandgap_match, &pdev->dev);
837	if (of_id)
838		bgp->conf = of_id->data;
839
840	/* register shadow for context save and restore */
841	bgp->regval = devm_kcalloc(&pdev->dev, bgp->conf->sensor_count,
842				   sizeof(*bgp->regval), GFP_KERNEL);
843	if (!bgp->regval)
844		return ERR_PTR(-ENOMEM);
845
846	i = 0;
847	do {
848		void __iomem *chunk;
849
850		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
851		if (!res)
852			break;
853		chunk = devm_ioremap_resource(&pdev->dev, res);
854		if (i == 0)
855			bgp->base = chunk;
856		if (IS_ERR(chunk))
857			return ERR_CAST(chunk);
858
859		i++;
860	} while (res);
861
862	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
863		bgp->tshut_gpiod = devm_gpiod_get(&pdev->dev, NULL, GPIOD_IN);
864		if (IS_ERR(bgp->tshut_gpiod)) {
865			dev_err(&pdev->dev, "invalid gpio for tshut\n");
866			return ERR_CAST(bgp->tshut_gpiod);
867		}
868	}
869
870	return bgp;
871}
872
873/*
874 * List of SoCs on which the CPU PM notifier can cause erros on the DTEMP
875 * readout.
876 * Enabled notifier on these machines results in erroneous, random values which
877 * could trigger unexpected thermal shutdown.
878 */
879static const struct soc_device_attribute soc_no_cpu_notifier[] = {
880	{ .machine = "OMAP4430" },
881	{ /* sentinel */ }
882};
883
884/***   Device driver call backs   ***/
885
886static
887int ti_bandgap_probe(struct platform_device *pdev)
888{
889	struct ti_bandgap *bgp;
890	int clk_rate, ret, i;
891
892	bgp = ti_bandgap_build(pdev);
893	if (IS_ERR(bgp)) {
894		dev_err(&pdev->dev, "failed to fetch platform data\n");
895		return PTR_ERR(bgp);
896	}
897	bgp->dev = &pdev->dev;
898
899	if (TI_BANDGAP_HAS(bgp, UNRELIABLE))
900		dev_warn(&pdev->dev,
901			 "This OMAP thermal sensor is unreliable. You've been warned\n");
902
903	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
904		ret = ti_bandgap_tshut_init(bgp, pdev);
905		if (ret) {
906			dev_err(&pdev->dev,
907				"failed to initialize system tshut IRQ\n");
908			return ret;
909		}
910	}
911
912	bgp->fclock = clk_get(NULL, bgp->conf->fclock_name);
913	if (IS_ERR(bgp->fclock)) {
914		dev_err(&pdev->dev, "failed to request fclock reference\n");
915		ret = PTR_ERR(bgp->fclock);
916		goto free_irqs;
917	}
918
919	bgp->div_clk = clk_get(NULL, bgp->conf->div_ck_name);
920	if (IS_ERR(bgp->div_clk)) {
921		dev_err(&pdev->dev, "failed to request div_ts_ck clock ref\n");
922		ret = PTR_ERR(bgp->div_clk);
923		goto put_fclock;
924	}
925
926	for (i = 0; i < bgp->conf->sensor_count; i++) {
927		struct temp_sensor_registers *tsr;
928		u32 val;
929
930		tsr = bgp->conf->sensors[i].registers;
931		/*
932		 * check if the efuse has a non-zero value if not
933		 * it is an untrimmed sample and the temperatures
934		 * may not be accurate
935		 */
936		val = ti_bandgap_readl(bgp, tsr->bgap_efuse);
937		if (!val)
938			dev_info(&pdev->dev,
939				 "Non-trimmed BGAP, Temp not accurate\n");
940	}
941
942	clk_rate = clk_round_rate(bgp->div_clk,
943				  bgp->conf->sensors[0].ts_data->max_freq);
944	if (clk_rate < bgp->conf->sensors[0].ts_data->min_freq ||
945	    clk_rate <= 0) {
946		ret = -ENODEV;
947		dev_err(&pdev->dev, "wrong clock rate (%d)\n", clk_rate);
948		goto put_clks;
949	}
950
951	ret = clk_set_rate(bgp->div_clk, clk_rate);
952	if (ret)
953		dev_err(&pdev->dev, "Cannot re-set clock rate. Continuing\n");
954
955	bgp->clk_rate = clk_rate;
956	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
957		clk_prepare_enable(bgp->fclock);
958
959
960	spin_lock_init(&bgp->lock);
961	bgp->dev = &pdev->dev;
962	platform_set_drvdata(pdev, bgp);
963
964	ti_bandgap_power(bgp, true);
965
966	/* Set default counter to 1 for now */
967	if (TI_BANDGAP_HAS(bgp, COUNTER))
968		for (i = 0; i < bgp->conf->sensor_count; i++)
969			RMW_BITS(bgp, i, bgap_counter, counter_mask, 1);
970
971	/* Set default thresholds for alert and shutdown */
972	for (i = 0; i < bgp->conf->sensor_count; i++) {
973		struct temp_sensor_data *ts_data;
974
975		ts_data = bgp->conf->sensors[i].ts_data;
976
977		if (TI_BANDGAP_HAS(bgp, TALERT)) {
978			/* Set initial Talert thresholds */
979			RMW_BITS(bgp, i, bgap_threshold,
980				 threshold_tcold_mask, ts_data->t_cold);
981			RMW_BITS(bgp, i, bgap_threshold,
982				 threshold_thot_mask, ts_data->t_hot);
983			/* Enable the alert events */
984			RMW_BITS(bgp, i, bgap_mask_ctrl, mask_hot_mask, 1);
985			RMW_BITS(bgp, i, bgap_mask_ctrl, mask_cold_mask, 1);
986		}
987
988		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG)) {
989			/* Set initial Tshut thresholds */
990			RMW_BITS(bgp, i, tshut_threshold,
991				 tshut_hot_mask, ts_data->tshut_hot);
992			RMW_BITS(bgp, i, tshut_threshold,
993				 tshut_cold_mask, ts_data->tshut_cold);
994		}
995	}
996
997	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
998		ti_bandgap_set_continuous_mode(bgp);
999
1000	/* Set .250 seconds time as default counter */
1001	if (TI_BANDGAP_HAS(bgp, COUNTER))
1002		for (i = 0; i < bgp->conf->sensor_count; i++)
1003			RMW_BITS(bgp, i, bgap_counter, counter_mask,
1004				 bgp->clk_rate / 4);
1005
1006	/* Every thing is good? Then expose the sensors */
1007	for (i = 0; i < bgp->conf->sensor_count; i++) {
1008		char *domain;
1009
1010		if (bgp->conf->sensors[i].register_cooling) {
1011			ret = bgp->conf->sensors[i].register_cooling(bgp, i);
1012			if (ret)
1013				goto remove_sensors;
1014		}
1015
1016		if (bgp->conf->expose_sensor) {
1017			domain = bgp->conf->sensors[i].domain;
1018			ret = bgp->conf->expose_sensor(bgp, i, domain);
1019			if (ret)
1020				goto remove_last_cooling;
1021		}
1022	}
1023
1024	/*
1025	 * Enable the Interrupts once everything is set. Otherwise irq handler
1026	 * might be called as soon as it is enabled where as rest of framework
1027	 * is still getting initialised.
1028	 */
1029	if (TI_BANDGAP_HAS(bgp, TALERT)) {
1030		ret = ti_bandgap_talert_init(bgp, pdev);
1031		if (ret) {
1032			dev_err(&pdev->dev, "failed to initialize Talert IRQ\n");
1033			i = bgp->conf->sensor_count;
1034			goto disable_clk;
1035		}
1036	}
1037
1038#ifdef CONFIG_PM_SLEEP
1039	bgp->nb.notifier_call = bandgap_omap_cpu_notifier;
1040	if (!soc_device_match(soc_no_cpu_notifier))
1041		cpu_pm_register_notifier(&bgp->nb);
1042#endif
1043
1044	return 0;
1045
1046remove_last_cooling:
1047	if (bgp->conf->sensors[i].unregister_cooling)
1048		bgp->conf->sensors[i].unregister_cooling(bgp, i);
1049remove_sensors:
1050	for (i--; i >= 0; i--) {
1051		if (bgp->conf->sensors[i].unregister_cooling)
1052			bgp->conf->sensors[i].unregister_cooling(bgp, i);
1053		if (bgp->conf->remove_sensor)
1054			bgp->conf->remove_sensor(bgp, i);
1055	}
1056	ti_bandgap_power(bgp, false);
1057disable_clk:
1058	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1059		clk_disable_unprepare(bgp->fclock);
1060put_clks:
1061	clk_put(bgp->div_clk);
1062put_fclock:
1063	clk_put(bgp->fclock);
1064free_irqs:
1065	if (TI_BANDGAP_HAS(bgp, TSHUT))
1066		free_irq(gpiod_to_irq(bgp->tshut_gpiod), NULL);
1067
1068	return ret;
1069}
1070
1071static
1072void ti_bandgap_remove(struct platform_device *pdev)
1073{
1074	struct ti_bandgap *bgp = platform_get_drvdata(pdev);
1075	int i;
1076
1077	if (!soc_device_match(soc_no_cpu_notifier))
1078		cpu_pm_unregister_notifier(&bgp->nb);
1079
1080	/* Remove sensor interfaces */
1081	for (i = 0; i < bgp->conf->sensor_count; i++) {
1082		if (bgp->conf->sensors[i].unregister_cooling)
1083			bgp->conf->sensors[i].unregister_cooling(bgp, i);
1084
1085		if (bgp->conf->remove_sensor)
1086			bgp->conf->remove_sensor(bgp, i);
1087	}
1088
1089	ti_bandgap_power(bgp, false);
1090
1091	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1092		clk_disable_unprepare(bgp->fclock);
1093	clk_put(bgp->fclock);
1094	clk_put(bgp->div_clk);
1095
1096	if (TI_BANDGAP_HAS(bgp, TALERT))
1097		free_irq(bgp->irq, bgp);
1098
1099	if (TI_BANDGAP_HAS(bgp, TSHUT))
1100		free_irq(gpiod_to_irq(bgp->tshut_gpiod), NULL);
1101}
1102
1103#ifdef CONFIG_PM_SLEEP
1104static int ti_bandgap_save_ctxt(struct ti_bandgap *bgp)
1105{
1106	int i;
1107
1108	for (i = 0; i < bgp->conf->sensor_count; i++) {
1109		struct temp_sensor_registers *tsr;
1110		struct temp_sensor_regval *rval;
1111
1112		rval = &bgp->regval[i];
1113		tsr = bgp->conf->sensors[i].registers;
1114
1115		if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
1116			rval->bg_mode_ctrl = ti_bandgap_readl(bgp,
1117							tsr->bgap_mode_ctrl);
1118		if (TI_BANDGAP_HAS(bgp, COUNTER))
1119			rval->bg_counter = ti_bandgap_readl(bgp,
1120							tsr->bgap_counter);
1121		if (TI_BANDGAP_HAS(bgp, TALERT)) {
1122			rval->bg_threshold = ti_bandgap_readl(bgp,
1123							tsr->bgap_threshold);
1124			rval->bg_ctrl = ti_bandgap_readl(bgp,
1125						   tsr->bgap_mask_ctrl);
1126		}
1127
1128		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG))
1129			rval->tshut_threshold = ti_bandgap_readl(bgp,
1130						   tsr->tshut_threshold);
1131	}
1132
1133	return 0;
1134}
1135
1136static int ti_bandgap_restore_ctxt(struct ti_bandgap *bgp)
1137{
1138	int i;
1139
1140	for (i = 0; i < bgp->conf->sensor_count; i++) {
1141		struct temp_sensor_registers *tsr;
1142		struct temp_sensor_regval *rval;
1143
1144		rval = &bgp->regval[i];
1145		tsr = bgp->conf->sensors[i].registers;
1146
1147		if (TI_BANDGAP_HAS(bgp, TSHUT_CONFIG))
1148			ti_bandgap_writel(bgp, rval->tshut_threshold,
1149					  tsr->tshut_threshold);
1150		/* Force immediate temperature measurement and update
1151		 * of the DTEMP field
1152		 */
1153		ti_bandgap_force_single_read(bgp, i);
1154
1155		if (TI_BANDGAP_HAS(bgp, COUNTER))
1156			ti_bandgap_writel(bgp, rval->bg_counter,
1157					  tsr->bgap_counter);
1158		if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
1159			ti_bandgap_writel(bgp, rval->bg_mode_ctrl,
1160					  tsr->bgap_mode_ctrl);
1161		if (TI_BANDGAP_HAS(bgp, TALERT)) {
1162			ti_bandgap_writel(bgp, rval->bg_threshold,
1163					  tsr->bgap_threshold);
1164			ti_bandgap_writel(bgp, rval->bg_ctrl,
1165					  tsr->bgap_mask_ctrl);
1166		}
1167	}
1168
1169	return 0;
1170}
1171
1172static int ti_bandgap_suspend(struct device *dev)
1173{
1174	struct ti_bandgap *bgp = dev_get_drvdata(dev);
1175	int err;
1176
1177	err = ti_bandgap_save_ctxt(bgp);
1178	ti_bandgap_power(bgp, false);
1179
1180	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1181		clk_disable_unprepare(bgp->fclock);
1182
1183	bgp->is_suspended = true;
1184
1185	return err;
1186}
1187
1188static int bandgap_omap_cpu_notifier(struct notifier_block *nb,
1189				  unsigned long cmd, void *v)
1190{
1191	struct ti_bandgap *bgp;
1192
1193	bgp = container_of(nb, struct ti_bandgap, nb);
1194
1195	spin_lock(&bgp->lock);
1196	switch (cmd) {
1197	case CPU_CLUSTER_PM_ENTER:
1198		if (bgp->is_suspended)
1199			break;
1200		ti_bandgap_save_ctxt(bgp);
1201		ti_bandgap_power(bgp, false);
1202		if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1203			clk_disable(bgp->fclock);
1204		break;
1205	case CPU_CLUSTER_PM_ENTER_FAILED:
1206	case CPU_CLUSTER_PM_EXIT:
1207		if (bgp->is_suspended)
1208			break;
1209		if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1210			clk_enable(bgp->fclock);
1211		ti_bandgap_power(bgp, true);
1212		ti_bandgap_restore_ctxt(bgp);
1213		break;
1214	}
1215	spin_unlock(&bgp->lock);
1216
1217	return NOTIFY_OK;
1218}
1219
1220static int ti_bandgap_resume(struct device *dev)
1221{
1222	struct ti_bandgap *bgp = dev_get_drvdata(dev);
1223
1224	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
1225		clk_prepare_enable(bgp->fclock);
1226
1227	ti_bandgap_power(bgp, true);
1228	bgp->is_suspended = false;
1229
1230	return ti_bandgap_restore_ctxt(bgp);
1231}
1232static SIMPLE_DEV_PM_OPS(ti_bandgap_dev_pm_ops, ti_bandgap_suspend,
1233			 ti_bandgap_resume);
1234
1235#define DEV_PM_OPS	(&ti_bandgap_dev_pm_ops)
1236#else
1237#define DEV_PM_OPS	NULL
1238#endif
1239
1240static const struct of_device_id of_ti_bandgap_match[] = {
1241#ifdef CONFIG_OMAP3_THERMAL
1242	{
1243		.compatible = "ti,omap34xx-bandgap",
1244		.data = (void *)&omap34xx_data,
1245	},
1246	{
1247		.compatible = "ti,omap36xx-bandgap",
1248		.data = (void *)&omap36xx_data,
1249	},
1250#endif
1251#ifdef CONFIG_OMAP4_THERMAL
1252	{
1253		.compatible = "ti,omap4430-bandgap",
1254		.data = (void *)&omap4430_data,
1255	},
1256	{
1257		.compatible = "ti,omap4460-bandgap",
1258		.data = (void *)&omap4460_data,
1259	},
1260	{
1261		.compatible = "ti,omap4470-bandgap",
1262		.data = (void *)&omap4470_data,
1263	},
1264#endif
1265#ifdef CONFIG_OMAP5_THERMAL
1266	{
1267		.compatible = "ti,omap5430-bandgap",
1268		.data = (void *)&omap5430_data,
1269	},
1270#endif
1271#ifdef CONFIG_DRA752_THERMAL
1272	{
1273		.compatible = "ti,dra752-bandgap",
1274		.data = (void *)&dra752_data,
1275	},
1276#endif
1277	/* Sentinel */
1278	{ },
1279};
1280MODULE_DEVICE_TABLE(of, of_ti_bandgap_match);
1281
1282static struct platform_driver ti_bandgap_sensor_driver = {
1283	.probe = ti_bandgap_probe,
1284	.remove_new = ti_bandgap_remove,
1285	.driver = {
1286			.name = "ti-soc-thermal",
1287			.pm = DEV_PM_OPS,
1288			.of_match_table	= of_ti_bandgap_match,
1289	},
1290};
1291
1292module_platform_driver(ti_bandgap_sensor_driver);
1293
1294MODULE_DESCRIPTION("OMAP4+ bandgap temperature sensor driver");
1295MODULE_LICENSE("GPL v2");
1296MODULE_ALIAS("platform:ti-soc-thermal");
1297MODULE_AUTHOR("Texas Instrument Inc.");
1298