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
rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc * tsc,u32 reg)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
rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc * tsc,u32 reg,u32 data)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
rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc * tsc,int * ptat,const int * thcode,int ths_tj_1)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
rcar_gen3_thermal_round(int temp)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
rcar_gen3_thermal_get_temp(void * devdata,int * temp)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
rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc * tsc,int mcelsius)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
rcar_gen3_thermal_set_trips(void * devdata,int low,int high)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
rcar_gen3_thermal_irq(int irq,void * data)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
rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc * tsc)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
rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc * tsc)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
rcar_gen3_thermal_remove(struct platform_device * pdev)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
rcar_gen3_hwmon_action(void * data)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
rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv * priv,struct platform_device * pdev)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
rcar_gen3_thermal_probe(struct platform_device * pdev)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
rcar_gen3_thermal_resume(struct device * dev)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
