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