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 3
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 };
71
72 /* Structure for thermal temperature calculation */
73 struct equation_coefs {
74 int a1;
75 int b1;
76 int a2;
77 int b2;
78 };
79
80 struct rcar_gen3_thermal_tsc {
81 void __iomem *base;
82 struct thermal_zone_device *zone;
83 struct equation_coefs coef;
84 int tj_t;
85 int id; /* thermal channel id */
86 };
87
88 struct rcar_gen3_thermal_priv {
89 struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
90 unsigned int num_tscs;
91 void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
92 };
93
rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc * tsc,u32 reg)94 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
95 u32 reg)
96 {
97 return ioread32(tsc->base + reg);
98 }
99
rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc * tsc,u32 reg,u32 data)100 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
101 u32 reg, u32 data)
102 {
103 iowrite32(data, tsc->base + reg);
104 }
105
106 /*
107 * Linear approximation for temperature
108 *
109 * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
110 *
111 * The constants a and b are calculated using two triplets of int values PTAT
112 * and THCODE. PTAT and THCODE can either be read from hardware or use hard
113 * coded values from driver. The formula to calculate a and b are taken from
114 * BSP and sparsely documented and understood.
115 *
116 * Examining the linear formula and the formula used to calculate constants a
117 * and b while knowing that the span for PTAT and THCODE values are between
118 * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
119 * Integer also needs to be signed so that leaves 7 bits for binary
120 * fixed point scaling.
121 */
122
123 #define FIXPT_SHIFT 7
124 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
125 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
126 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
127 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
128
129 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
130
131 /* no idea where these constants come from */
132 #define TJ_3 -41
133
rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc * tsc,int * ptat,const int * thcode,int ths_tj_1)134 static void rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc *tsc,
135 int *ptat, const int *thcode,
136 int ths_tj_1)
137 {
138 /* TODO: Find documentation and document constant calculation formula */
139
140 /*
141 * Division is not scaled in BSP and if scaled it might overflow
142 * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
143 */
144 tsc->tj_t = (FIXPT_INT((ptat[1] - ptat[2]) * (ths_tj_1 - TJ_3))
145 / (ptat[0] - ptat[2])) + FIXPT_INT(TJ_3);
146
147 tsc->coef.a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
148 tsc->tj_t - FIXPT_INT(TJ_3));
149 tsc->coef.b1 = FIXPT_INT(thcode[2]) - tsc->coef.a1 * TJ_3;
150
151 tsc->coef.a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
152 tsc->tj_t - FIXPT_INT(ths_tj_1));
153 tsc->coef.b2 = FIXPT_INT(thcode[0]) - tsc->coef.a2 * ths_tj_1;
154 }
155
rcar_gen3_thermal_round(int temp)156 static int rcar_gen3_thermal_round(int temp)
157 {
158 int result, round_offs;
159
160 round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
161 -RCAR3_THERMAL_GRAN / 2;
162 result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
163 return result * RCAR3_THERMAL_GRAN;
164 }
165
rcar_gen3_thermal_get_temp(void * devdata,int * temp)166 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
167 {
168 struct rcar_gen3_thermal_tsc *tsc = devdata;
169 int mcelsius, val;
170 int reg;
171
172 /* Read register and convert to mili Celsius */
173 reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
174
175 if (reg <= thcodes[tsc->id][1])
176 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1,
177 tsc->coef.a1);
178 else
179 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2,
180 tsc->coef.a2);
181 mcelsius = FIXPT_TO_MCELSIUS(val);
182
183 /* Guaranteed operating range is -40C to 125C. */
184
185 /* Round value to device granularity setting */
186 *temp = rcar_gen3_thermal_round(mcelsius);
187
188 return 0;
189 }
190
rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc * tsc,int mcelsius)191 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
192 int mcelsius)
193 {
194 int celsius, val;
195
196 celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
197 if (celsius <= INT_FIXPT(tsc->tj_t))
198 val = celsius * tsc->coef.a1 + tsc->coef.b1;
199 else
200 val = celsius * tsc->coef.a2 + tsc->coef.b2;
201
202 return INT_FIXPT(val);
203 }
204
rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc * tsc)205 static int rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc *tsc)
206 {
207 int temperature, low, high;
208
209 rcar_gen3_thermal_get_temp(tsc, &temperature);
210
211 low = temperature - MCELSIUS(1);
212 high = temperature + MCELSIUS(1);
213
214 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
215 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
216
217 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
218 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
219
220 return 0;
221 }
222
223 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
224 .get_temp = rcar_gen3_thermal_get_temp,
225 };
226
rcar_thermal_irq_set(struct rcar_gen3_thermal_priv * priv,bool on)227 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
228 {
229 unsigned int i;
230 u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
231
232 for (i = 0; i < priv->num_tscs; i++)
233 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
234 }
235
rcar_gen3_thermal_irq(int irq,void * data)236 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
237 {
238 struct rcar_gen3_thermal_priv *priv = data;
239 u32 status;
240 int i;
241
242 for (i = 0; i < priv->num_tscs; i++) {
243 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
244 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
245 if (status) {
246 rcar_gen3_thermal_update_range(priv->tscs[i]);
247 thermal_zone_device_update(priv->tscs[i]->zone,
248 THERMAL_EVENT_UNSPECIFIED);
249 }
250 }
251
252 return IRQ_HANDLED;
253 }
254
255 static const struct soc_device_attribute r8a7795es1[] = {
256 { .soc_id = "r8a7795", .revision = "ES1.*" },
257 { /* sentinel */ }
258 };
259
rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc * tsc)260 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
261 {
262 rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_THBGR);
263 rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, 0x0);
264
265 usleep_range(1000, 2000);
266
267 rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
268
269 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
270 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
271 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
272
273 rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
274 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
275
276 usleep_range(100, 200);
277
278 rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
279 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
280 CTSR_VMST | CTSR_THSST);
281
282 usleep_range(1000, 2000);
283 }
284
rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc * tsc)285 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
286 {
287 u32 reg_val;
288
289 reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
290 reg_val &= ~THCTR_PONM;
291 rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
292
293 usleep_range(1000, 2000);
294
295 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
296 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
297 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, 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 };
343 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
344
rcar_gen3_thermal_remove(struct platform_device * pdev)345 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
346 {
347 struct device *dev = &pdev->dev;
348 struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
349
350 rcar_thermal_irq_set(priv, false);
351
352 pm_runtime_put(dev);
353 pm_runtime_disable(dev);
354
355 return 0;
356 }
357
rcar_gen3_hwmon_action(void * data)358 static void rcar_gen3_hwmon_action(void *data)
359 {
360 struct thermal_zone_device *zone = data;
361
362 thermal_remove_hwmon_sysfs(zone);
363 }
364
rcar_gen3_thermal_probe(struct platform_device * pdev)365 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
366 {
367 struct rcar_gen3_thermal_priv *priv;
368 struct device *dev = &pdev->dev;
369 const int *ths_tj_1 = of_device_get_match_data(dev);
370 struct resource *res;
371 struct thermal_zone_device *zone;
372 int ret, irq, i;
373 char *irqname;
374
375 /* default values if FUSEs are missing */
376 /* TODO: Read values from hardware on supported platforms */
377 int ptat[3] = { 2631, 1509, 435 };
378
379 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
380 if (!priv)
381 return -ENOMEM;
382
383 priv->thermal_init = rcar_gen3_thermal_init;
384 if (soc_device_match(r8a7795es1))
385 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
386
387 platform_set_drvdata(pdev, priv);
388
389 /*
390 * Request 2 (of the 3 possible) IRQs, the driver only needs to
391 * to trigger on the low and high trip points of the current
392 * temp window at this point.
393 */
394 for (i = 0; i < 2; i++) {
395 irq = platform_get_irq(pdev, i);
396 if (irq < 0)
397 return irq;
398
399 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
400 dev_name(dev), i);
401 if (!irqname)
402 return -ENOMEM;
403
404 ret = devm_request_threaded_irq(dev, irq, NULL,
405 rcar_gen3_thermal_irq,
406 IRQF_ONESHOT, irqname, priv);
407 if (ret)
408 return ret;
409 }
410
411 pm_runtime_enable(dev);
412 pm_runtime_get_sync(dev);
413
414 for (i = 0; i < TSC_MAX_NUM; i++) {
415 struct rcar_gen3_thermal_tsc *tsc;
416
417 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
418 if (!res)
419 break;
420
421 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
422 if (!tsc) {
423 ret = -ENOMEM;
424 goto error_unregister;
425 }
426
427 tsc->base = devm_ioremap_resource(dev, res);
428 if (IS_ERR(tsc->base)) {
429 ret = PTR_ERR(tsc->base);
430 goto error_unregister;
431 }
432 tsc->id = i;
433
434 priv->tscs[i] = tsc;
435
436 priv->thermal_init(tsc);
437 rcar_gen3_thermal_calc_coefs(tsc, ptat, thcodes[i], *ths_tj_1);
438
439 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
440 &rcar_gen3_tz_of_ops);
441 if (IS_ERR(zone)) {
442 dev_err(dev, "Can't register thermal zone\n");
443 ret = PTR_ERR(zone);
444 goto error_unregister;
445 }
446 tsc->zone = zone;
447
448 tsc->zone->tzp->no_hwmon = false;
449 ret = thermal_add_hwmon_sysfs(tsc->zone);
450 if (ret)
451 goto error_unregister;
452
453 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
454 if (ret)
455 goto error_unregister;
456
457 ret = of_thermal_get_ntrips(tsc->zone);
458 if (ret < 0)
459 goto error_unregister;
460
461 rcar_gen3_thermal_update_range(tsc);
462
463 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
464 }
465
466 priv->num_tscs = i;
467
468 if (!priv->num_tscs) {
469 ret = -ENODEV;
470 goto error_unregister;
471 }
472
473 rcar_thermal_irq_set(priv, true);
474
475 return 0;
476
477 error_unregister:
478 rcar_gen3_thermal_remove(pdev);
479
480 return ret;
481 }
482
rcar_gen3_thermal_suspend(struct device * dev)483 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
484 {
485 struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
486
487 rcar_thermal_irq_set(priv, false);
488
489 return 0;
490 }
491
rcar_gen3_thermal_resume(struct device * dev)492 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
493 {
494 struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
495 unsigned int i;
496
497 for (i = 0; i < priv->num_tscs; i++) {
498 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
499
500 priv->thermal_init(tsc);
501 rcar_gen3_thermal_update_range(tsc);
502 }
503
504 rcar_thermal_irq_set(priv, true);
505
506 return 0;
507 }
508
509 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
510 rcar_gen3_thermal_resume);
511
512 static struct platform_driver rcar_gen3_thermal_driver = {
513 .driver = {
514 .name = "rcar_gen3_thermal",
515 .pm = &rcar_gen3_thermal_pm_ops,
516 .of_match_table = rcar_gen3_thermal_dt_ids,
517 },
518 .probe = rcar_gen3_thermal_probe,
519 .remove = rcar_gen3_thermal_remove,
520 };
521 module_platform_driver(rcar_gen3_thermal_driver);
522
523 MODULE_LICENSE("GPL v2");
524 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
525 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
526