1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  R-Car Gen3 THS thermal sensor driver
4  *  Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen.
5  *
6  * Copyright (C) 2016 Renesas Electronics Corporation.
7  * Copyright (C) 2016 Sang Engineering
8  */
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/of_device.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/sys_soc.h>
18 #include <linux/thermal.h>
19 
20 #include "thermal_core.h"
21 #include "thermal_hwmon.h"
22 
23 /* Register offsets */
24 #define REG_GEN3_IRQSTR		0x04
25 #define REG_GEN3_IRQMSK		0x08
26 #define REG_GEN3_IRQCTL		0x0C
27 #define REG_GEN3_IRQEN		0x10
28 #define REG_GEN3_IRQTEMP1	0x14
29 #define REG_GEN3_IRQTEMP2	0x18
30 #define REG_GEN3_IRQTEMP3	0x1C
31 #define REG_GEN3_CTSR		0x20
32 #define REG_GEN3_THCTR		0x20
33 #define REG_GEN3_TEMP		0x28
34 #define REG_GEN3_THCODE1	0x50
35 #define REG_GEN3_THCODE2	0x54
36 #define REG_GEN3_THCODE3	0x58
37 
38 /* IRQ{STR,MSK,EN} bits */
39 #define IRQ_TEMP1		BIT(0)
40 #define IRQ_TEMP2		BIT(1)
41 #define IRQ_TEMP3		BIT(2)
42 #define IRQ_TEMPD1		BIT(3)
43 #define IRQ_TEMPD2		BIT(4)
44 #define IRQ_TEMPD3		BIT(5)
45 
46 /* CTSR bits */
47 #define CTSR_PONM	BIT(8)
48 #define CTSR_AOUT	BIT(7)
49 #define CTSR_THBGR	BIT(5)
50 #define CTSR_VMEN	BIT(4)
51 #define CTSR_VMST	BIT(1)
52 #define CTSR_THSST	BIT(0)
53 
54 /* THCTR bits */
55 #define THCTR_PONM	BIT(6)
56 #define THCTR_THSST	BIT(0)
57 
58 #define CTEMP_MASK	0xFFF
59 
60 #define MCELSIUS(temp)	((temp) * 1000)
61 #define GEN3_FUSE_MASK	0xFFF
62 
63 #define TSC_MAX_NUM	5
64 
65 /* default THCODE values if FUSEs are missing */
66 static const int thcodes[TSC_MAX_NUM][3] = {
67 	{ 3397, 2800, 2221 },
68 	{ 3393, 2795, 2216 },
69 	{ 3389, 2805, 2237 },
70 	{ 3415, 2694, 2195 },
71 	{ 3356, 2724, 2244 },
72 };
73 
74 /* Structure for thermal temperature calculation */
75 struct equation_coefs {
76 	int a1;
77 	int b1;
78 	int a2;
79 	int b2;
80 };
81 
82 struct rcar_gen3_thermal_tsc {
83 	void __iomem *base;
84 	struct thermal_zone_device *zone;
85 	struct equation_coefs coef;
86 	int tj_t;
87 	unsigned int id; /* thermal channel id */
88 };
89 
90 struct rcar_gen3_thermal_priv {
91 	struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
92 	unsigned int num_tscs;
93 	void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
94 };
95 
96 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
97 					 u32 reg)
98 {
99 	return ioread32(tsc->base + reg);
100 }
101 
102 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
103 					   u32 reg, u32 data)
104 {
105 	iowrite32(data, tsc->base + reg);
106 }
107 
108 /*
109  * Linear approximation for temperature
110  *
111  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
112  *
113  * The constants a and b are calculated using two triplets of int values PTAT
114  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
115  * coded values from driver. The formula to calculate a and b are taken from
116  * BSP and sparsely documented and understood.
117  *
118  * Examining the linear formula and the formula used to calculate constants a
119  * and b while knowing that the span for PTAT and THCODE values are between
120  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
121  * Integer also needs to be signed so that leaves 7 bits for binary
122  * fixed point scaling.
123  */
124 
125 #define FIXPT_SHIFT 7
126 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
127 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
128 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
129 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
130 
131 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
132 
133 /* no idea where these constants come from */
134 #define TJ_3 -41
135 
136 static void rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc *tsc,
137 					 int *ptat, const int *thcode,
138 					 int ths_tj_1)
139 {
140 	/* TODO: Find documentation and document constant calculation formula */
141 
142 	/*
143 	 * Division is not scaled in BSP and if scaled it might overflow
144 	 * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
145 	 */
146 	tsc->tj_t = (FIXPT_INT((ptat[1] - ptat[2]) * (ths_tj_1 - TJ_3))
147 		     / (ptat[0] - ptat[2])) + FIXPT_INT(TJ_3);
148 
149 	tsc->coef.a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
150 				 tsc->tj_t - FIXPT_INT(TJ_3));
151 	tsc->coef.b1 = FIXPT_INT(thcode[2]) - tsc->coef.a1 * TJ_3;
152 
153 	tsc->coef.a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
154 				 tsc->tj_t - FIXPT_INT(ths_tj_1));
155 	tsc->coef.b2 = FIXPT_INT(thcode[0]) - tsc->coef.a2 * ths_tj_1;
156 }
157 
158 static int rcar_gen3_thermal_round(int temp)
159 {
160 	int result, round_offs;
161 
162 	round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
163 		-RCAR3_THERMAL_GRAN / 2;
164 	result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
165 	return result * RCAR3_THERMAL_GRAN;
166 }
167 
168 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
169 {
170 	struct rcar_gen3_thermal_tsc *tsc = devdata;
171 	int mcelsius, val;
172 	int reg;
173 
174 	/* Read register and convert to mili Celsius */
175 	reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
176 
177 	if (reg <= thcodes[tsc->id][1])
178 		val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1,
179 				tsc->coef.a1);
180 	else
181 		val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2,
182 				tsc->coef.a2);
183 	mcelsius = FIXPT_TO_MCELSIUS(val);
184 
185 	/* Guaranteed operating range is -40C to 125C. */
186 
187 	/* Round value to device granularity setting */
188 	*temp = rcar_gen3_thermal_round(mcelsius);
189 
190 	return 0;
191 }
192 
193 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
194 					      int mcelsius)
195 {
196 	int celsius, val;
197 
198 	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
199 	if (celsius <= INT_FIXPT(tsc->tj_t))
200 		val = celsius * tsc->coef.a1 + tsc->coef.b1;
201 	else
202 		val = celsius * tsc->coef.a2 + tsc->coef.b2;
203 
204 	return INT_FIXPT(val);
205 }
206 
207 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
208 {
209 	struct rcar_gen3_thermal_tsc *tsc = devdata;
210 	u32 irqmsk = 0;
211 
212 	if (low != -INT_MAX) {
213 		irqmsk |= IRQ_TEMPD1;
214 		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
215 					rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
216 	}
217 
218 	if (high != INT_MAX) {
219 		irqmsk |= IRQ_TEMP2;
220 		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
221 					rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
222 	}
223 
224 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, irqmsk);
225 
226 	return 0;
227 }
228 
229 static struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
230 	.get_temp	= rcar_gen3_thermal_get_temp,
231 	.set_trips	= rcar_gen3_thermal_set_trips,
232 };
233 
234 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
235 {
236 	struct rcar_gen3_thermal_priv *priv = data;
237 	unsigned int i;
238 	u32 status;
239 
240 	for (i = 0; i < priv->num_tscs; i++) {
241 		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
242 		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
243 		if (status)
244 			thermal_zone_device_update(priv->tscs[i]->zone,
245 						   THERMAL_EVENT_UNSPECIFIED);
246 	}
247 
248 	return IRQ_HANDLED;
249 }
250 
251 static const struct soc_device_attribute r8a7795es1[] = {
252 	{ .soc_id = "r8a7795", .revision = "ES1.*" },
253 	{ /* sentinel */ }
254 };
255 
256 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
257 {
258 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
259 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
260 
261 	usleep_range(1000, 2000);
262 
263 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
264 
265 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
266 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
267 	if (tsc->zone->ops->set_trips)
268 		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
269 					IRQ_TEMPD1 | IRQ_TEMP2);
270 
271 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
272 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
273 
274 	usleep_range(100, 200);
275 
276 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
277 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
278 				CTSR_VMST | CTSR_THSST);
279 
280 	usleep_range(1000, 2000);
281 }
282 
283 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
284 {
285 	u32 reg_val;
286 
287 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
288 	reg_val &= ~THCTR_PONM;
289 	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
290 
291 	usleep_range(1000, 2000);
292 
293 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
294 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
295 	if (tsc->zone->ops->set_trips)
296 		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
297 					IRQ_TEMPD1 | IRQ_TEMP2);
298 
299 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
300 	reg_val |= THCTR_THSST;
301 	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
302 
303 	usleep_range(1000, 2000);
304 }
305 
306 static const int rcar_gen3_ths_tj_1 = 126;
307 static const int rcar_gen3_ths_tj_1_m3_w = 116;
308 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
309 	{
310 		.compatible = "renesas,r8a774a1-thermal",
311 		.data = &rcar_gen3_ths_tj_1_m3_w,
312 	},
313 	{
314 		.compatible = "renesas,r8a774b1-thermal",
315 		.data = &rcar_gen3_ths_tj_1,
316 	},
317 	{
318 		.compatible = "renesas,r8a774e1-thermal",
319 		.data = &rcar_gen3_ths_tj_1,
320 	},
321 	{
322 		.compatible = "renesas,r8a7795-thermal",
323 		.data = &rcar_gen3_ths_tj_1,
324 	},
325 	{
326 		.compatible = "renesas,r8a7796-thermal",
327 		.data = &rcar_gen3_ths_tj_1_m3_w,
328 	},
329 	{
330 		.compatible = "renesas,r8a77961-thermal",
331 		.data = &rcar_gen3_ths_tj_1_m3_w,
332 	},
333 	{
334 		.compatible = "renesas,r8a77965-thermal",
335 		.data = &rcar_gen3_ths_tj_1,
336 	},
337 	{
338 		.compatible = "renesas,r8a77980-thermal",
339 		.data = &rcar_gen3_ths_tj_1,
340 	},
341 	{
342 		.compatible = "renesas,r8a779a0-thermal",
343 		.data = &rcar_gen3_ths_tj_1,
344 	},
345 	{},
346 };
347 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
348 
349 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
350 {
351 	struct device *dev = &pdev->dev;
352 
353 	pm_runtime_put(dev);
354 	pm_runtime_disable(dev);
355 
356 	return 0;
357 }
358 
359 static void rcar_gen3_hwmon_action(void *data)
360 {
361 	struct thermal_zone_device *zone = data;
362 
363 	thermal_remove_hwmon_sysfs(zone);
364 }
365 
366 static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv,
367 					  struct platform_device *pdev)
368 {
369 	struct device *dev = &pdev->dev;
370 	unsigned int i;
371 	char *irqname;
372 	int ret, irq;
373 
374 	for (i = 0; i < 2; i++) {
375 		irq = platform_get_irq_optional(pdev, i);
376 		if (irq < 0)
377 			return irq;
378 
379 		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
380 					 dev_name(dev), i);
381 		if (!irqname)
382 			return -ENOMEM;
383 
384 		ret = devm_request_threaded_irq(dev, irq, NULL,
385 						rcar_gen3_thermal_irq,
386 						IRQF_ONESHOT, irqname, priv);
387 		if (ret)
388 			return ret;
389 	}
390 
391 	return 0;
392 }
393 
394 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
395 {
396 	struct rcar_gen3_thermal_priv *priv;
397 	struct device *dev = &pdev->dev;
398 	const int *ths_tj_1 = of_device_get_match_data(dev);
399 	struct resource *res;
400 	struct thermal_zone_device *zone;
401 	unsigned int i;
402 	int ret;
403 
404 	/* default values if FUSEs are missing */
405 	/* TODO: Read values from hardware on supported platforms */
406 	int ptat[3] = { 2631, 1509, 435 };
407 
408 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
409 	if (!priv)
410 		return -ENOMEM;
411 
412 	priv->thermal_init = rcar_gen3_thermal_init;
413 	if (soc_device_match(r8a7795es1))
414 		priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
415 
416 	platform_set_drvdata(pdev, priv);
417 
418 	if (rcar_gen3_thermal_request_irqs(priv, pdev))
419 		rcar_gen3_tz_of_ops.set_trips = NULL;
420 
421 	pm_runtime_enable(dev);
422 	pm_runtime_get_sync(dev);
423 
424 	for (i = 0; i < TSC_MAX_NUM; i++) {
425 		struct rcar_gen3_thermal_tsc *tsc;
426 
427 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
428 		if (!res)
429 			break;
430 
431 		tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
432 		if (!tsc) {
433 			ret = -ENOMEM;
434 			goto error_unregister;
435 		}
436 
437 		tsc->base = devm_ioremap_resource(dev, res);
438 		if (IS_ERR(tsc->base)) {
439 			ret = PTR_ERR(tsc->base);
440 			goto error_unregister;
441 		}
442 		tsc->id = i;
443 
444 		priv->tscs[i] = tsc;
445 
446 		zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
447 							    &rcar_gen3_tz_of_ops);
448 		if (IS_ERR(zone)) {
449 			dev_err(dev, "Can't register thermal zone\n");
450 			ret = PTR_ERR(zone);
451 			goto error_unregister;
452 		}
453 		tsc->zone = zone;
454 
455 		priv->thermal_init(tsc);
456 		rcar_gen3_thermal_calc_coefs(tsc, ptat, thcodes[i], *ths_tj_1);
457 
458 		tsc->zone->tzp->no_hwmon = false;
459 		ret = thermal_add_hwmon_sysfs(tsc->zone);
460 		if (ret)
461 			goto error_unregister;
462 
463 		ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
464 		if (ret)
465 			goto error_unregister;
466 
467 		ret = of_thermal_get_ntrips(tsc->zone);
468 		if (ret < 0)
469 			goto error_unregister;
470 
471 		dev_info(dev, "TSC%u: Loaded %d trip points\n", i, ret);
472 	}
473 
474 	priv->num_tscs = i;
475 
476 	if (!priv->num_tscs) {
477 		ret = -ENODEV;
478 		goto error_unregister;
479 	}
480 
481 	return 0;
482 
483 error_unregister:
484 	rcar_gen3_thermal_remove(pdev);
485 
486 	return ret;
487 }
488 
489 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
490 {
491 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
492 	unsigned int i;
493 
494 	for (i = 0; i < priv->num_tscs; i++) {
495 		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
496 		struct thermal_zone_device *zone = tsc->zone;
497 
498 		priv->thermal_init(tsc);
499 		if (zone->ops->set_trips)
500 			rcar_gen3_thermal_set_trips(tsc, zone->prev_low_trip,
501 						    zone->prev_high_trip);
502 	}
503 
504 	return 0;
505 }
506 
507 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
508 			 rcar_gen3_thermal_resume);
509 
510 static struct platform_driver rcar_gen3_thermal_driver = {
511 	.driver	= {
512 		.name	= "rcar_gen3_thermal",
513 		.pm = &rcar_gen3_thermal_pm_ops,
514 		.of_match_table = rcar_gen3_thermal_dt_ids,
515 	},
516 	.probe		= rcar_gen3_thermal_probe,
517 	.remove		= rcar_gen3_thermal_remove,
518 };
519 module_platform_driver(rcar_gen3_thermal_driver);
520 
521 MODULE_LICENSE("GPL v2");
522 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
523 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
524