1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Marvell EBU Armada SoCs thermal sensor driver
4  *
5  * Copyright (C) 2013 Marvell
6  */
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/kernel.h>
11 #include <linux/of.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/platform_device.h>
15 #include <linux/of_device.h>
16 #include <linux/thermal.h>
17 #include <linux/iopoll.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/regmap.h>
20 #include <linux/interrupt.h>
21 
22 #include "thermal_core.h"
23 
24 /* Thermal Manager Control and Status Register */
25 #define PMU_TDC0_SW_RST_MASK		(0x1 << 1)
26 #define PMU_TM_DISABLE_OFFS		0
27 #define PMU_TM_DISABLE_MASK		(0x1 << PMU_TM_DISABLE_OFFS)
28 #define PMU_TDC0_REF_CAL_CNT_OFFS	11
29 #define PMU_TDC0_REF_CAL_CNT_MASK	(0x1ff << PMU_TDC0_REF_CAL_CNT_OFFS)
30 #define PMU_TDC0_OTF_CAL_MASK		(0x1 << 30)
31 #define PMU_TDC0_START_CAL_MASK		(0x1 << 25)
32 
33 #define A375_UNIT_CONTROL_SHIFT		27
34 #define A375_UNIT_CONTROL_MASK		0x7
35 #define A375_READOUT_INVERT		BIT(15)
36 #define A375_HW_RESETn			BIT(8)
37 
38 /* Errata fields */
39 #define CONTROL0_TSEN_TC_TRIM_MASK	0x7
40 #define CONTROL0_TSEN_TC_TRIM_VAL	0x3
41 
42 #define CONTROL0_TSEN_START		BIT(0)
43 #define CONTROL0_TSEN_RESET		BIT(1)
44 #define CONTROL0_TSEN_ENABLE		BIT(2)
45 #define CONTROL0_TSEN_AVG_BYPASS	BIT(6)
46 #define CONTROL0_TSEN_CHAN_SHIFT	13
47 #define CONTROL0_TSEN_CHAN_MASK		0xF
48 #define CONTROL0_TSEN_OSR_SHIFT		24
49 #define CONTROL0_TSEN_OSR_MAX		0x3
50 #define CONTROL0_TSEN_MODE_SHIFT	30
51 #define CONTROL0_TSEN_MODE_EXTERNAL	0x2
52 #define CONTROL0_TSEN_MODE_MASK		0x3
53 
54 #define CONTROL1_TSEN_AVG_MASK		0x7
55 #define CONTROL1_EXT_TSEN_SW_RESET	BIT(7)
56 #define CONTROL1_EXT_TSEN_HW_RESETn	BIT(8)
57 #define CONTROL1_TSEN_INT_EN		BIT(25)
58 #define CONTROL1_TSEN_SELECT_OFF	21
59 #define CONTROL1_TSEN_SELECT_MASK	0x3
60 
61 #define STATUS_POLL_PERIOD_US		1000
62 #define STATUS_POLL_TIMEOUT_US		100000
63 #define OVERHEAT_INT_POLL_DELAY_MS	1000
64 
65 struct armada_thermal_data;
66 
67 /* Marvell EBU Thermal Sensor Dev Structure */
68 struct armada_thermal_priv {
69 	struct device *dev;
70 	struct regmap *syscon;
71 	char zone_name[THERMAL_NAME_LENGTH];
72 	/* serialize temperature reads/updates */
73 	struct mutex update_lock;
74 	struct armada_thermal_data *data;
75 	struct thermal_zone_device *overheat_sensor;
76 	int interrupt_source;
77 	int current_channel;
78 	long current_threshold;
79 	long current_hysteresis;
80 };
81 
82 struct armada_thermal_data {
83 	/* Initialize the thermal IC */
84 	void (*init)(struct platform_device *pdev,
85 		     struct armada_thermal_priv *priv);
86 
87 	/* Formula coeficients: temp = (b - m * reg) / div */
88 	s64 coef_b;
89 	s64 coef_m;
90 	u32 coef_div;
91 	bool inverted;
92 	bool signed_sample;
93 
94 	/* Register shift and mask to access the sensor temperature */
95 	unsigned int temp_shift;
96 	unsigned int temp_mask;
97 	unsigned int thresh_shift;
98 	unsigned int hyst_shift;
99 	unsigned int hyst_mask;
100 	u32 is_valid_bit;
101 
102 	/* Syscon access */
103 	unsigned int syscon_control0_off;
104 	unsigned int syscon_control1_off;
105 	unsigned int syscon_status_off;
106 	unsigned int dfx_irq_cause_off;
107 	unsigned int dfx_irq_mask_off;
108 	unsigned int dfx_overheat_irq;
109 	unsigned int dfx_server_irq_mask_off;
110 	unsigned int dfx_server_irq_en;
111 
112 	/* One sensor is in the thermal IC, the others are in the CPUs if any */
113 	unsigned int cpu_nr;
114 };
115 
116 struct armada_drvdata {
117 	enum drvtype {
118 		LEGACY,
119 		SYSCON
120 	} type;
121 	union {
122 		struct armada_thermal_priv *priv;
123 		struct thermal_zone_device *tz;
124 	} data;
125 };
126 
127 /*
128  * struct armada_thermal_sensor - hold the information of one thermal sensor
129  * @thermal: pointer to the local private structure
130  * @tzd: pointer to the thermal zone device
131  * @id: identifier of the thermal sensor
132  */
133 struct armada_thermal_sensor {
134 	struct armada_thermal_priv *priv;
135 	int id;
136 };
137 
138 static void armadaxp_init(struct platform_device *pdev,
139 			  struct armada_thermal_priv *priv)
140 {
141 	struct armada_thermal_data *data = priv->data;
142 	u32 reg;
143 
144 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
145 	reg |= PMU_TDC0_OTF_CAL_MASK;
146 
147 	/* Reference calibration value */
148 	reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
149 	reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
150 
151 	/* Reset the sensor */
152 	reg |= PMU_TDC0_SW_RST_MASK;
153 
154 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
155 
156 	reg &= ~PMU_TDC0_SW_RST_MASK;
157 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
158 
159 	/* Enable the sensor */
160 	regmap_read(priv->syscon, data->syscon_status_off, &reg);
161 	reg &= ~PMU_TM_DISABLE_MASK;
162 	regmap_write(priv->syscon, data->syscon_status_off, reg);
163 }
164 
165 static void armada370_init(struct platform_device *pdev,
166 			   struct armada_thermal_priv *priv)
167 {
168 	struct armada_thermal_data *data = priv->data;
169 	u32 reg;
170 
171 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
172 	reg |= PMU_TDC0_OTF_CAL_MASK;
173 
174 	/* Reference calibration value */
175 	reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
176 	reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
177 
178 	/* Reset the sensor */
179 	reg &= ~PMU_TDC0_START_CAL_MASK;
180 
181 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
182 
183 	msleep(10);
184 }
185 
186 static void armada375_init(struct platform_device *pdev,
187 			   struct armada_thermal_priv *priv)
188 {
189 	struct armada_thermal_data *data = priv->data;
190 	u32 reg;
191 
192 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
193 	reg &= ~(A375_UNIT_CONTROL_MASK << A375_UNIT_CONTROL_SHIFT);
194 	reg &= ~A375_READOUT_INVERT;
195 	reg &= ~A375_HW_RESETn;
196 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
197 
198 	msleep(20);
199 
200 	reg |= A375_HW_RESETn;
201 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
202 
203 	msleep(50);
204 }
205 
206 static int armada_wait_sensor_validity(struct armada_thermal_priv *priv)
207 {
208 	u32 reg;
209 
210 	return regmap_read_poll_timeout(priv->syscon,
211 					priv->data->syscon_status_off, reg,
212 					reg & priv->data->is_valid_bit,
213 					STATUS_POLL_PERIOD_US,
214 					STATUS_POLL_TIMEOUT_US);
215 }
216 
217 static void armada380_init(struct platform_device *pdev,
218 			   struct armada_thermal_priv *priv)
219 {
220 	struct armada_thermal_data *data = priv->data;
221 	u32 reg;
222 
223 	/* Disable the HW/SW reset */
224 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
225 	reg |= CONTROL1_EXT_TSEN_HW_RESETn;
226 	reg &= ~CONTROL1_EXT_TSEN_SW_RESET;
227 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
228 
229 	/* Set Tsen Tc Trim to correct default value (errata #132698) */
230 	regmap_read(priv->syscon, data->syscon_control0_off, &reg);
231 	reg &= ~CONTROL0_TSEN_TC_TRIM_MASK;
232 	reg |= CONTROL0_TSEN_TC_TRIM_VAL;
233 	regmap_write(priv->syscon, data->syscon_control0_off, reg);
234 }
235 
236 static void armada_ap806_init(struct platform_device *pdev,
237 			      struct armada_thermal_priv *priv)
238 {
239 	struct armada_thermal_data *data = priv->data;
240 	u32 reg;
241 
242 	regmap_read(priv->syscon, data->syscon_control0_off, &reg);
243 	reg &= ~CONTROL0_TSEN_RESET;
244 	reg |= CONTROL0_TSEN_START | CONTROL0_TSEN_ENABLE;
245 
246 	/* Sample every ~2ms */
247 	reg |= CONTROL0_TSEN_OSR_MAX << CONTROL0_TSEN_OSR_SHIFT;
248 
249 	/* Enable average (2 samples by default) */
250 	reg &= ~CONTROL0_TSEN_AVG_BYPASS;
251 
252 	regmap_write(priv->syscon, data->syscon_control0_off, reg);
253 }
254 
255 static void armada_cp110_init(struct platform_device *pdev,
256 			      struct armada_thermal_priv *priv)
257 {
258 	struct armada_thermal_data *data = priv->data;
259 	u32 reg;
260 
261 	armada380_init(pdev, priv);
262 
263 	/* Sample every ~2ms */
264 	regmap_read(priv->syscon, data->syscon_control0_off, &reg);
265 	reg |= CONTROL0_TSEN_OSR_MAX << CONTROL0_TSEN_OSR_SHIFT;
266 	regmap_write(priv->syscon, data->syscon_control0_off, reg);
267 
268 	/* Average the output value over 2^1 = 2 samples */
269 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
270 	reg &= ~CONTROL1_TSEN_AVG_MASK;
271 	reg |= 1;
272 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
273 }
274 
275 static bool armada_is_valid(struct armada_thermal_priv *priv)
276 {
277 	u32 reg;
278 
279 	if (!priv->data->is_valid_bit)
280 		return true;
281 
282 	regmap_read(priv->syscon, priv->data->syscon_status_off, &reg);
283 
284 	return reg & priv->data->is_valid_bit;
285 }
286 
287 static void armada_enable_overheat_interrupt(struct armada_thermal_priv *priv)
288 {
289 	struct armada_thermal_data *data = priv->data;
290 	u32 reg;
291 
292 	/* Clear DFX temperature IRQ cause */
293 	regmap_read(priv->syscon, data->dfx_irq_cause_off, &reg);
294 
295 	/* Enable DFX Temperature IRQ */
296 	regmap_read(priv->syscon, data->dfx_irq_mask_off, &reg);
297 	reg |= data->dfx_overheat_irq;
298 	regmap_write(priv->syscon, data->dfx_irq_mask_off, reg);
299 
300 	/* Enable DFX server IRQ */
301 	regmap_read(priv->syscon, data->dfx_server_irq_mask_off, &reg);
302 	reg |= data->dfx_server_irq_en;
303 	regmap_write(priv->syscon, data->dfx_server_irq_mask_off, reg);
304 
305 	/* Enable overheat interrupt */
306 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
307 	reg |= CONTROL1_TSEN_INT_EN;
308 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
309 }
310 
311 static void __maybe_unused
312 armada_disable_overheat_interrupt(struct armada_thermal_priv *priv)
313 {
314 	struct armada_thermal_data *data = priv->data;
315 	u32 reg;
316 
317 	regmap_read(priv->syscon, data->syscon_control1_off, &reg);
318 	reg &= ~CONTROL1_TSEN_INT_EN;
319 	regmap_write(priv->syscon, data->syscon_control1_off, reg);
320 }
321 
322 /* There is currently no board with more than one sensor per channel */
323 static int armada_select_channel(struct armada_thermal_priv *priv, int channel)
324 {
325 	struct armada_thermal_data *data = priv->data;
326 	u32 ctrl0;
327 
328 	if (channel < 0 || channel > priv->data->cpu_nr)
329 		return -EINVAL;
330 
331 	if (priv->current_channel == channel)
332 		return 0;
333 
334 	/* Stop the measurements */
335 	regmap_read(priv->syscon, data->syscon_control0_off, &ctrl0);
336 	ctrl0 &= ~CONTROL0_TSEN_START;
337 	regmap_write(priv->syscon, data->syscon_control0_off, ctrl0);
338 
339 	/* Reset the mode, internal sensor will be automatically selected */
340 	ctrl0 &= ~(CONTROL0_TSEN_MODE_MASK << CONTROL0_TSEN_MODE_SHIFT);
341 
342 	/* Other channels are external and should be selected accordingly */
343 	if (channel) {
344 		/* Change the mode to external */
345 		ctrl0 |= CONTROL0_TSEN_MODE_EXTERNAL <<
346 			 CONTROL0_TSEN_MODE_SHIFT;
347 		/* Select the sensor */
348 		ctrl0 &= ~(CONTROL0_TSEN_CHAN_MASK << CONTROL0_TSEN_CHAN_SHIFT);
349 		ctrl0 |= (channel - 1) << CONTROL0_TSEN_CHAN_SHIFT;
350 	}
351 
352 	/* Actually set the mode/channel */
353 	regmap_write(priv->syscon, data->syscon_control0_off, ctrl0);
354 	priv->current_channel = channel;
355 
356 	/* Re-start the measurements */
357 	ctrl0 |= CONTROL0_TSEN_START;
358 	regmap_write(priv->syscon, data->syscon_control0_off, ctrl0);
359 
360 	/*
361 	 * The IP has a latency of ~15ms, so after updating the selected source,
362 	 * we must absolutely wait for the sensor validity bit to ensure we read
363 	 * actual data.
364 	 */
365 	if (armada_wait_sensor_validity(priv)) {
366 		dev_err(priv->dev,
367 			"Temperature sensor reading not valid\n");
368 		return -EIO;
369 	}
370 
371 	return 0;
372 }
373 
374 static int armada_read_sensor(struct armada_thermal_priv *priv, int *temp)
375 {
376 	u32 reg, div;
377 	s64 sample, b, m;
378 
379 	regmap_read(priv->syscon, priv->data->syscon_status_off, &reg);
380 	reg = (reg >> priv->data->temp_shift) & priv->data->temp_mask;
381 	if (priv->data->signed_sample)
382 		/* The most significant bit is the sign bit */
383 		sample = sign_extend32(reg, fls(priv->data->temp_mask) - 1);
384 	else
385 		sample = reg;
386 
387 	/* Get formula coeficients */
388 	b = priv->data->coef_b;
389 	m = priv->data->coef_m;
390 	div = priv->data->coef_div;
391 
392 	if (priv->data->inverted)
393 		*temp = div_s64((m * sample) - b, div);
394 	else
395 		*temp = div_s64(b - (m * sample), div);
396 
397 	return 0;
398 }
399 
400 static int armada_get_temp_legacy(struct thermal_zone_device *thermal,
401 				  int *temp)
402 {
403 	struct armada_thermal_priv *priv = thermal->devdata;
404 	int ret;
405 
406 	/* Valid check */
407 	if (!armada_is_valid(priv)) {
408 		dev_err(priv->dev,
409 			"Temperature sensor reading not valid\n");
410 		return -EIO;
411 	}
412 
413 	/* Do the actual reading */
414 	ret = armada_read_sensor(priv, temp);
415 
416 	return ret;
417 }
418 
419 static struct thermal_zone_device_ops legacy_ops = {
420 	.get_temp = armada_get_temp_legacy,
421 };
422 
423 static int armada_get_temp(void *_sensor, int *temp)
424 {
425 	struct armada_thermal_sensor *sensor = _sensor;
426 	struct armada_thermal_priv *priv = sensor->priv;
427 	int ret;
428 
429 	mutex_lock(&priv->update_lock);
430 
431 	/* Select the desired channel */
432 	ret = armada_select_channel(priv, sensor->id);
433 	if (ret)
434 		goto unlock_mutex;
435 
436 	/* Do the actual reading */
437 	ret = armada_read_sensor(priv, temp);
438 	if (ret)
439 		goto unlock_mutex;
440 
441 	/*
442 	 * Select back the interrupt source channel from which a potential
443 	 * critical trip point has been set.
444 	 */
445 	ret = armada_select_channel(priv, priv->interrupt_source);
446 
447 unlock_mutex:
448 	mutex_unlock(&priv->update_lock);
449 
450 	return ret;
451 }
452 
453 static const struct thermal_zone_of_device_ops of_ops = {
454 	.get_temp = armada_get_temp,
455 };
456 
457 static unsigned int armada_mc_to_reg_temp(struct armada_thermal_data *data,
458 					  unsigned int temp_mc)
459 {
460 	s64 b = data->coef_b;
461 	s64 m = data->coef_m;
462 	s64 div = data->coef_div;
463 	unsigned int sample;
464 
465 	if (data->inverted)
466 		sample = div_s64(((temp_mc * div) + b), m);
467 	else
468 		sample = div_s64((b - (temp_mc * div)), m);
469 
470 	return sample & data->temp_mask;
471 }
472 
473 /*
474  * The documentation states:
475  * high/low watermark = threshold +/- 0.4761 * 2^(hysteresis + 2)
476  * which is the mathematical derivation for:
477  * 0x0 <=> 1.9°C, 0x1 <=> 3.8°C, 0x2 <=> 7.6°C, 0x3 <=> 15.2°C
478  */
479 static unsigned int hyst_levels_mc[] = {1900, 3800, 7600, 15200};
480 
481 static unsigned int armada_mc_to_reg_hyst(struct armada_thermal_data *data,
482 					  unsigned int hyst_mc)
483 {
484 	int i;
485 
486 	/*
487 	 * We will always take the smallest possible hysteresis to avoid risking
488 	 * the hardware integrity by enlarging the threshold by +8°C in the
489 	 * worst case.
490 	 */
491 	for (i = ARRAY_SIZE(hyst_levels_mc) - 1; i > 0; i--)
492 		if (hyst_mc >= hyst_levels_mc[i])
493 			break;
494 
495 	return i & data->hyst_mask;
496 }
497 
498 static void armada_set_overheat_thresholds(struct armada_thermal_priv *priv,
499 					   int thresh_mc, int hyst_mc)
500 {
501 	struct armada_thermal_data *data = priv->data;
502 	unsigned int threshold = armada_mc_to_reg_temp(data, thresh_mc);
503 	unsigned int hysteresis = armada_mc_to_reg_hyst(data, hyst_mc);
504 	u32 ctrl1;
505 
506 	regmap_read(priv->syscon, data->syscon_control1_off, &ctrl1);
507 
508 	/* Set Threshold */
509 	if (thresh_mc >= 0) {
510 		ctrl1 &= ~(data->temp_mask << data->thresh_shift);
511 		ctrl1 |= threshold << data->thresh_shift;
512 		priv->current_threshold = thresh_mc;
513 	}
514 
515 	/* Set Hysteresis */
516 	if (hyst_mc >= 0) {
517 		ctrl1 &= ~(data->hyst_mask << data->hyst_shift);
518 		ctrl1 |= hysteresis << data->hyst_shift;
519 		priv->current_hysteresis = hyst_mc;
520 	}
521 
522 	regmap_write(priv->syscon, data->syscon_control1_off, ctrl1);
523 }
524 
525 static irqreturn_t armada_overheat_isr(int irq, void *blob)
526 {
527 	/*
528 	 * Disable the IRQ and continue in thread context (thermal core
529 	 * notification and temperature monitoring).
530 	 */
531 	disable_irq_nosync(irq);
532 
533 	return IRQ_WAKE_THREAD;
534 }
535 
536 static irqreturn_t armada_overheat_isr_thread(int irq, void *blob)
537 {
538 	struct armada_thermal_priv *priv = blob;
539 	int low_threshold = priv->current_threshold - priv->current_hysteresis;
540 	int temperature;
541 	u32 dummy;
542 	int ret;
543 
544 	/* Notify the core in thread context */
545 	thermal_zone_device_update(priv->overheat_sensor,
546 				   THERMAL_EVENT_UNSPECIFIED);
547 
548 	/*
549 	 * The overheat interrupt must be cleared by reading the DFX interrupt
550 	 * cause _after_ the temperature has fallen down to the low threshold.
551 	 * Otherwise future interrupts might not be served.
552 	 */
553 	do {
554 		msleep(OVERHEAT_INT_POLL_DELAY_MS);
555 		mutex_lock(&priv->update_lock);
556 		ret = armada_read_sensor(priv, &temperature);
557 		mutex_unlock(&priv->update_lock);
558 		if (ret)
559 			goto enable_irq;
560 	} while (temperature >= low_threshold);
561 
562 	regmap_read(priv->syscon, priv->data->dfx_irq_cause_off, &dummy);
563 
564 	/* Notify the thermal core that the temperature is acceptable again */
565 	thermal_zone_device_update(priv->overheat_sensor,
566 				   THERMAL_EVENT_UNSPECIFIED);
567 
568 enable_irq:
569 	enable_irq(irq);
570 
571 	return IRQ_HANDLED;
572 }
573 
574 static const struct armada_thermal_data armadaxp_data = {
575 	.init = armadaxp_init,
576 	.temp_shift = 10,
577 	.temp_mask = 0x1ff,
578 	.coef_b = 3153000000ULL,
579 	.coef_m = 10000000ULL,
580 	.coef_div = 13825,
581 	.syscon_status_off = 0xb0,
582 	.syscon_control1_off = 0x2d0,
583 };
584 
585 static const struct armada_thermal_data armada370_data = {
586 	.init = armada370_init,
587 	.is_valid_bit = BIT(9),
588 	.temp_shift = 10,
589 	.temp_mask = 0x1ff,
590 	.coef_b = 3153000000ULL,
591 	.coef_m = 10000000ULL,
592 	.coef_div = 13825,
593 	.syscon_status_off = 0x0,
594 	.syscon_control1_off = 0x4,
595 };
596 
597 static const struct armada_thermal_data armada375_data = {
598 	.init = armada375_init,
599 	.is_valid_bit = BIT(10),
600 	.temp_shift = 0,
601 	.temp_mask = 0x1ff,
602 	.coef_b = 3171900000ULL,
603 	.coef_m = 10000000ULL,
604 	.coef_div = 13616,
605 	.syscon_status_off = 0x78,
606 	.syscon_control0_off = 0x7c,
607 	.syscon_control1_off = 0x80,
608 };
609 
610 static const struct armada_thermal_data armada380_data = {
611 	.init = armada380_init,
612 	.is_valid_bit = BIT(10),
613 	.temp_shift = 0,
614 	.temp_mask = 0x3ff,
615 	.coef_b = 1172499100ULL,
616 	.coef_m = 2000096ULL,
617 	.coef_div = 4201,
618 	.inverted = true,
619 	.syscon_control0_off = 0x70,
620 	.syscon_control1_off = 0x74,
621 	.syscon_status_off = 0x78,
622 };
623 
624 static const struct armada_thermal_data armada_ap806_data = {
625 	.init = armada_ap806_init,
626 	.is_valid_bit = BIT(16),
627 	.temp_shift = 0,
628 	.temp_mask = 0x3ff,
629 	.thresh_shift = 3,
630 	.hyst_shift = 19,
631 	.hyst_mask = 0x3,
632 	.coef_b = -150000LL,
633 	.coef_m = 423ULL,
634 	.coef_div = 1,
635 	.inverted = true,
636 	.signed_sample = true,
637 	.syscon_control0_off = 0x84,
638 	.syscon_control1_off = 0x88,
639 	.syscon_status_off = 0x8C,
640 	.dfx_irq_cause_off = 0x108,
641 	.dfx_irq_mask_off = 0x10C,
642 	.dfx_overheat_irq = BIT(22),
643 	.dfx_server_irq_mask_off = 0x104,
644 	.dfx_server_irq_en = BIT(1),
645 	.cpu_nr = 4,
646 };
647 
648 static const struct armada_thermal_data armada_cp110_data = {
649 	.init = armada_cp110_init,
650 	.is_valid_bit = BIT(10),
651 	.temp_shift = 0,
652 	.temp_mask = 0x3ff,
653 	.thresh_shift = 16,
654 	.hyst_shift = 26,
655 	.hyst_mask = 0x3,
656 	.coef_b = 1172499100ULL,
657 	.coef_m = 2000096ULL,
658 	.coef_div = 4201,
659 	.inverted = true,
660 	.syscon_control0_off = 0x70,
661 	.syscon_control1_off = 0x74,
662 	.syscon_status_off = 0x78,
663 	.dfx_irq_cause_off = 0x108,
664 	.dfx_irq_mask_off = 0x10C,
665 	.dfx_overheat_irq = BIT(20),
666 	.dfx_server_irq_mask_off = 0x104,
667 	.dfx_server_irq_en = BIT(1),
668 };
669 
670 static const struct of_device_id armada_thermal_id_table[] = {
671 	{
672 		.compatible = "marvell,armadaxp-thermal",
673 		.data       = &armadaxp_data,
674 	},
675 	{
676 		.compatible = "marvell,armada370-thermal",
677 		.data       = &armada370_data,
678 	},
679 	{
680 		.compatible = "marvell,armada375-thermal",
681 		.data       = &armada375_data,
682 	},
683 	{
684 		.compatible = "marvell,armada380-thermal",
685 		.data       = &armada380_data,
686 	},
687 	{
688 		.compatible = "marvell,armada-ap806-thermal",
689 		.data       = &armada_ap806_data,
690 	},
691 	{
692 		.compatible = "marvell,armada-cp110-thermal",
693 		.data       = &armada_cp110_data,
694 	},
695 	{
696 		/* sentinel */
697 	},
698 };
699 MODULE_DEVICE_TABLE(of, armada_thermal_id_table);
700 
701 static const struct regmap_config armada_thermal_regmap_config = {
702 	.reg_bits = 32,
703 	.reg_stride = 4,
704 	.val_bits = 32,
705 	.fast_io = true,
706 };
707 
708 static int armada_thermal_probe_legacy(struct platform_device *pdev,
709 				       struct armada_thermal_priv *priv)
710 {
711 	struct armada_thermal_data *data = priv->data;
712 	struct resource *res;
713 	void __iomem *base;
714 
715 	/* First memory region points towards the status register */
716 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
717 	base = devm_ioremap_resource(&pdev->dev, res);
718 	if (IS_ERR(base))
719 		return PTR_ERR(base);
720 
721 	/*
722 	 * Fix up from the old individual DT register specification to
723 	 * cover all the registers.  We do this by adjusting the ioremap()
724 	 * result, which should be fine as ioremap() deals with pages.
725 	 * However, validate that we do not cross a page boundary while
726 	 * making this adjustment.
727 	 */
728 	if (((unsigned long)base & ~PAGE_MASK) < data->syscon_status_off)
729 		return -EINVAL;
730 	base -= data->syscon_status_off;
731 
732 	priv->syscon = devm_regmap_init_mmio(&pdev->dev, base,
733 					     &armada_thermal_regmap_config);
734 	return PTR_ERR_OR_ZERO(priv->syscon);
735 }
736 
737 static int armada_thermal_probe_syscon(struct platform_device *pdev,
738 				       struct armada_thermal_priv *priv)
739 {
740 	priv->syscon = syscon_node_to_regmap(pdev->dev.parent->of_node);
741 	return PTR_ERR_OR_ZERO(priv->syscon);
742 }
743 
744 static void armada_set_sane_name(struct platform_device *pdev,
745 				 struct armada_thermal_priv *priv)
746 {
747 	const char *name = dev_name(&pdev->dev);
748 	char *insane_char;
749 
750 	if (strlen(name) > THERMAL_NAME_LENGTH) {
751 		/*
752 		 * When inside a system controller, the device name has the
753 		 * form: f06f8000.system-controller:ap-thermal so stripping
754 		 * after the ':' should give us a shorter but meaningful name.
755 		 */
756 		name = strrchr(name, ':');
757 		if (!name)
758 			name = "armada_thermal";
759 		else
760 			name++;
761 	}
762 
763 	/* Save the name locally */
764 	strncpy(priv->zone_name, name, THERMAL_NAME_LENGTH - 1);
765 	priv->zone_name[THERMAL_NAME_LENGTH - 1] = '\0';
766 
767 	/* Then check there are no '-' or hwmon core will complain */
768 	do {
769 		insane_char = strpbrk(priv->zone_name, "-");
770 		if (insane_char)
771 			*insane_char = '_';
772 	} while (insane_char);
773 }
774 
775 /*
776  * The IP can manage to trigger interrupts on overheat situation from all the
777  * sensors. However, the interrupt source changes along with the last selected
778  * source (ie. the last read sensor), which is an inconsistent behavior. Avoid
779  * possible glitches by always selecting back only one channel (arbitrarily: the
780  * first in the DT which has a critical trip point). We also disable sensor
781  * switch during overheat situations.
782  */
783 static int armada_configure_overheat_int(struct armada_thermal_priv *priv,
784 					 struct thermal_zone_device *tz,
785 					 int sensor_id)
786 {
787 	/* Retrieve the critical trip point to enable the overheat interrupt */
788 	const struct thermal_trip *trips = of_thermal_get_trip_points(tz);
789 	int ret;
790 	int i;
791 
792 	if (!trips)
793 		return -EINVAL;
794 
795 	for (i = 0; i < of_thermal_get_ntrips(tz); i++)
796 		if (trips[i].type == THERMAL_TRIP_CRITICAL)
797 			break;
798 
799 	if (i == of_thermal_get_ntrips(tz))
800 		return -EINVAL;
801 
802 	ret = armada_select_channel(priv, sensor_id);
803 	if (ret)
804 		return ret;
805 
806 	armada_set_overheat_thresholds(priv,
807 				       trips[i].temperature,
808 				       trips[i].hysteresis);
809 	priv->overheat_sensor = tz;
810 	priv->interrupt_source = sensor_id;
811 
812 	armada_enable_overheat_interrupt(priv);
813 
814 	return 0;
815 }
816 
817 static int armada_thermal_probe(struct platform_device *pdev)
818 {
819 	struct thermal_zone_device *tz;
820 	struct armada_thermal_sensor *sensor;
821 	struct armada_drvdata *drvdata;
822 	const struct of_device_id *match;
823 	struct armada_thermal_priv *priv;
824 	int sensor_id, irq;
825 	int ret;
826 
827 	match = of_match_device(armada_thermal_id_table, &pdev->dev);
828 	if (!match)
829 		return -ENODEV;
830 
831 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
832 	if (!priv)
833 		return -ENOMEM;
834 
835 	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
836 	if (!drvdata)
837 		return -ENOMEM;
838 
839 	priv->dev = &pdev->dev;
840 	priv->data = (struct armada_thermal_data *)match->data;
841 
842 	mutex_init(&priv->update_lock);
843 
844 	/*
845 	 * Legacy DT bindings only described "control1" register (also referred
846 	 * as "control MSB" on old documentation). Then, bindings moved to cover
847 	 * "control0/control LSB" and "control1/control MSB" registers within
848 	 * the same resource, which was then of size 8 instead of 4.
849 	 *
850 	 * The logic of defining sporadic registers is broken. For instance, it
851 	 * blocked the addition of the overheat interrupt feature that needed
852 	 * another resource somewhere else in the same memory area. One solution
853 	 * is to define an overall system controller and put the thermal node
854 	 * into it, which requires the use of regmaps across all the driver.
855 	 */
856 	if (IS_ERR(syscon_node_to_regmap(pdev->dev.parent->of_node))) {
857 		/* Ensure device name is correct for the thermal core */
858 		armada_set_sane_name(pdev, priv);
859 
860 		ret = armada_thermal_probe_legacy(pdev, priv);
861 		if (ret)
862 			return ret;
863 
864 		priv->data->init(pdev, priv);
865 
866 		/* Wait the sensors to be valid */
867 		armada_wait_sensor_validity(priv);
868 
869 		tz = thermal_zone_device_register(priv->zone_name, 0, 0, priv,
870 						  &legacy_ops, NULL, 0, 0);
871 		if (IS_ERR(tz)) {
872 			dev_err(&pdev->dev,
873 				"Failed to register thermal zone device\n");
874 			return PTR_ERR(tz);
875 		}
876 
877 		ret = thermal_zone_device_enable(tz);
878 		if (ret) {
879 			thermal_zone_device_unregister(tz);
880 			return ret;
881 		}
882 
883 		drvdata->type = LEGACY;
884 		drvdata->data.tz = tz;
885 		platform_set_drvdata(pdev, drvdata);
886 
887 		return 0;
888 	}
889 
890 	ret = armada_thermal_probe_syscon(pdev, priv);
891 	if (ret)
892 		return ret;
893 
894 	priv->current_channel = -1;
895 	priv->data->init(pdev, priv);
896 	drvdata->type = SYSCON;
897 	drvdata->data.priv = priv;
898 	platform_set_drvdata(pdev, drvdata);
899 
900 	irq = platform_get_irq(pdev, 0);
901 	if (irq == -EPROBE_DEFER)
902 		return irq;
903 
904 	/* The overheat interrupt feature is not mandatory */
905 	if (irq > 0) {
906 		ret = devm_request_threaded_irq(&pdev->dev, irq,
907 						armada_overheat_isr,
908 						armada_overheat_isr_thread,
909 						0, NULL, priv);
910 		if (ret) {
911 			dev_err(&pdev->dev, "Cannot request threaded IRQ %d\n",
912 				irq);
913 			return ret;
914 		}
915 	}
916 
917 	/*
918 	 * There is one channel for the IC and one per CPU (if any), each
919 	 * channel has one sensor.
920 	 */
921 	for (sensor_id = 0; sensor_id <= priv->data->cpu_nr; sensor_id++) {
922 		sensor = devm_kzalloc(&pdev->dev,
923 				      sizeof(struct armada_thermal_sensor),
924 				      GFP_KERNEL);
925 		if (!sensor)
926 			return -ENOMEM;
927 
928 		/* Register the sensor */
929 		sensor->priv = priv;
930 		sensor->id = sensor_id;
931 		tz = devm_thermal_zone_of_sensor_register(&pdev->dev,
932 							  sensor->id, sensor,
933 							  &of_ops);
934 		if (IS_ERR(tz)) {
935 			dev_info(&pdev->dev, "Thermal sensor %d unavailable\n",
936 				 sensor_id);
937 			devm_kfree(&pdev->dev, sensor);
938 			continue;
939 		}
940 
941 		/*
942 		 * The first channel that has a critical trip point registered
943 		 * in the DT will serve as interrupt source. Others possible
944 		 * critical trip points will simply be ignored by the driver.
945 		 */
946 		if (irq > 0 && !priv->overheat_sensor)
947 			armada_configure_overheat_int(priv, tz, sensor->id);
948 	}
949 
950 	/* Just complain if no overheat interrupt was set up */
951 	if (!priv->overheat_sensor)
952 		dev_warn(&pdev->dev, "Overheat interrupt not available\n");
953 
954 	return 0;
955 }
956 
957 static int armada_thermal_exit(struct platform_device *pdev)
958 {
959 	struct armada_drvdata *drvdata = platform_get_drvdata(pdev);
960 
961 	if (drvdata->type == LEGACY)
962 		thermal_zone_device_unregister(drvdata->data.tz);
963 
964 	return 0;
965 }
966 
967 static struct platform_driver armada_thermal_driver = {
968 	.probe = armada_thermal_probe,
969 	.remove = armada_thermal_exit,
970 	.driver = {
971 		.name = "armada_thermal",
972 		.of_match_table = armada_thermal_id_table,
973 	},
974 };
975 
976 module_platform_driver(armada_thermal_driver);
977 
978 MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
979 MODULE_DESCRIPTION("Marvell EBU Armada SoCs thermal driver");
980 MODULE_LICENSE("GPL v2");
981