Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[muen/linux.git] / drivers / thermal / rcar_gen3_thermal.c
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/spinlock.h>
18 #include <linux/sys_soc.h>
19 #include <linux/thermal.h>
20
21 #include "thermal_core.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 /* Structure for thermal temperature calculation */
66 struct equation_coefs {
67         int a1;
68         int b1;
69         int a2;
70         int b2;
71 };
72
73 struct rcar_gen3_thermal_tsc {
74         void __iomem *base;
75         struct thermal_zone_device *zone;
76         struct equation_coefs coef;
77         int low;
78         int high;
79 };
80
81 struct rcar_gen3_thermal_priv {
82         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
83         unsigned int num_tscs;
84         spinlock_t lock; /* Protect interrupts on and off */
85         void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
86 };
87
88 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
89                                          u32 reg)
90 {
91         return ioread32(tsc->base + reg);
92 }
93
94 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
95                                            u32 reg, u32 data)
96 {
97         iowrite32(data, tsc->base + reg);
98 }
99
100 /*
101  * Linear approximation for temperature
102  *
103  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
104  *
105  * The constants a and b are calculated using two triplets of int values PTAT
106  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
107  * coded values from driver. The formula to calculate a and b are taken from
108  * BSP and sparsely documented and understood.
109  *
110  * Examining the linear formula and the formula used to calculate constants a
111  * and b while knowing that the span for PTAT and THCODE values are between
112  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
113  * Integer also needs to be signed so that leaves 7 bits for binary
114  * fixed point scaling.
115  */
116
117 #define FIXPT_SHIFT 7
118 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
119 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
120 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
121 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
122
123 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
124
125 /* no idea where these constants come from */
126 #define TJ_1 116
127 #define TJ_3 -41
128
129 static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
130                                          int *ptat, int *thcode)
131 {
132         int tj_2;
133
134         /* TODO: Find documentation and document constant calculation formula */
135
136         /*
137          * Division is not scaled in BSP and if scaled it might overflow
138          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
139          */
140         tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
141                 / (ptat[0] - ptat[2])) - FIXPT_INT(41);
142
143         coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
144                              tj_2 - FIXPT_INT(TJ_3));
145         coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;
146
147         coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
148                              tj_2 - FIXPT_INT(TJ_1));
149         coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
150 }
151
152 static int rcar_gen3_thermal_round(int temp)
153 {
154         int result, round_offs;
155
156         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
157                 -RCAR3_THERMAL_GRAN / 2;
158         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
159         return result * RCAR3_THERMAL_GRAN;
160 }
161
162 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
163 {
164         struct rcar_gen3_thermal_tsc *tsc = devdata;
165         int mcelsius, val1, val2;
166         u32 reg;
167
168         /* Read register and convert to mili Celsius */
169         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
170
171         val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
172         val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
173         mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);
174
175         /* Make sure we are inside specifications */
176         if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
177                 return -EIO;
178
179         /* Round value to device granularity setting */
180         *temp = rcar_gen3_thermal_round(mcelsius);
181
182         return 0;
183 }
184
185 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
186                                               int mcelsius)
187 {
188         int celsius, val1, val2;
189
190         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
191         val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
192         val2 = celsius * tsc->coef.a2 + tsc->coef.b2;
193
194         return INT_FIXPT((val1 + val2) / 2);
195 }
196
197 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
198 {
199         struct rcar_gen3_thermal_tsc *tsc = devdata;
200
201         low = clamp_val(low, -40000, 120000);
202         high = clamp_val(high, -40000, 120000);
203
204         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
205                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
206
207         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
208                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
209
210         tsc->low = low;
211         tsc->high = high;
212
213         return 0;
214 }
215
216 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
217         .get_temp       = rcar_gen3_thermal_get_temp,
218         .set_trips      = rcar_gen3_thermal_set_trips,
219 };
220
221 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
222 {
223         unsigned int i;
224         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
225
226         for (i = 0; i < priv->num_tscs; i++)
227                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
228 }
229
230 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
231 {
232         struct rcar_gen3_thermal_priv *priv = data;
233         u32 status;
234         int i, ret = IRQ_HANDLED;
235
236         spin_lock(&priv->lock);
237         for (i = 0; i < priv->num_tscs; i++) {
238                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
239                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
240                 if (status)
241                         ret = IRQ_WAKE_THREAD;
242         }
243
244         if (ret == IRQ_WAKE_THREAD)
245                 rcar_thermal_irq_set(priv, false);
246
247         spin_unlock(&priv->lock);
248
249         return ret;
250 }
251
252 static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
253 {
254         struct rcar_gen3_thermal_priv *priv = data;
255         unsigned long flags;
256         int i;
257
258         for (i = 0; i < priv->num_tscs; i++)
259                 thermal_zone_device_update(priv->tscs[i]->zone,
260                                            THERMAL_EVENT_UNSPECIFIED);
261
262         spin_lock_irqsave(&priv->lock, flags);
263         rcar_thermal_irq_set(priv, true);
264         spin_unlock_irqrestore(&priv->lock, flags);
265
266         return IRQ_HANDLED;
267 }
268
269 static const struct soc_device_attribute r8a7795es1[] = {
270         { .soc_id = "r8a7795", .revision = "ES1.*" },
271         { /* sentinel */ }
272 };
273
274 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
275 {
276         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
277         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
278
279         usleep_range(1000, 2000);
280
281         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
282
283         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
284         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
285         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
286
287         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
288                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
289
290         usleep_range(100, 200);
291
292         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
293                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
294                                 CTSR_VMST | CTSR_THSST);
295
296         usleep_range(1000, 2000);
297 }
298
299 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
300 {
301         u32 reg_val;
302
303         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
304         reg_val &= ~THCTR_PONM;
305         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
306
307         usleep_range(1000, 2000);
308
309         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
310         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
311         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
312
313         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
314         reg_val |= THCTR_THSST;
315         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
316
317         usleep_range(1000, 2000);
318 }
319
320 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
321         { .compatible = "renesas,r8a774a1-thermal", },
322         { .compatible = "renesas,r8a7795-thermal", },
323         { .compatible = "renesas,r8a7796-thermal", },
324         { .compatible = "renesas,r8a77965-thermal", },
325         { .compatible = "renesas,r8a77980-thermal", },
326         {},
327 };
328 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
329
330 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
331 {
332         struct device *dev = &pdev->dev;
333
334         pm_runtime_put(dev);
335         pm_runtime_disable(dev);
336
337         return 0;
338 }
339
340 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
341 {
342         struct rcar_gen3_thermal_priv *priv;
343         struct device *dev = &pdev->dev;
344         struct resource *res;
345         struct thermal_zone_device *zone;
346         int ret, irq, i;
347         char *irqname;
348
349         /* default values if FUSEs are missing */
350         /* TODO: Read values from hardware on supported platforms */
351         int ptat[3] = { 2631, 1509, 435 };
352         int thcode[TSC_MAX_NUM][3] = {
353                 { 3397, 2800, 2221 },
354                 { 3393, 2795, 2216 },
355                 { 3389, 2805, 2237 },
356         };
357
358         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
359         if (!priv)
360                 return -ENOMEM;
361
362         priv->thermal_init = rcar_gen3_thermal_init;
363         if (soc_device_match(r8a7795es1))
364                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
365
366         spin_lock_init(&priv->lock);
367
368         platform_set_drvdata(pdev, priv);
369
370         /*
371          * Request 2 (of the 3 possible) IRQs, the driver only needs to
372          * to trigger on the low and high trip points of the current
373          * temp window at this point.
374          */
375         for (i = 0; i < 2; i++) {
376                 irq = platform_get_irq(pdev, i);
377                 if (irq < 0)
378                         return irq;
379
380                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
381                                          dev_name(dev), i);
382                 if (!irqname)
383                         return -ENOMEM;
384
385                 ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
386                                                 rcar_gen3_thermal_irq_thread,
387                                                 IRQF_SHARED, irqname, priv);
388                 if (ret)
389                         return ret;
390         }
391
392         pm_runtime_enable(dev);
393         pm_runtime_get_sync(dev);
394
395         for (i = 0; i < TSC_MAX_NUM; i++) {
396                 struct rcar_gen3_thermal_tsc *tsc;
397
398                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
399                 if (!res)
400                         break;
401
402                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
403                 if (!tsc) {
404                         ret = -ENOMEM;
405                         goto error_unregister;
406                 }
407
408                 tsc->base = devm_ioremap_resource(dev, res);
409                 if (IS_ERR(tsc->base)) {
410                         ret = PTR_ERR(tsc->base);
411                         goto error_unregister;
412                 }
413
414                 priv->tscs[i] = tsc;
415
416                 priv->thermal_init(tsc);
417                 rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);
418
419                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
420                                                             &rcar_gen3_tz_of_ops);
421                 if (IS_ERR(zone)) {
422                         dev_err(dev, "Can't register thermal zone\n");
423                         ret = PTR_ERR(zone);
424                         goto error_unregister;
425                 }
426                 tsc->zone = zone;
427
428                 ret = of_thermal_get_ntrips(tsc->zone);
429                 if (ret < 0)
430                         goto error_unregister;
431
432                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
433         }
434
435         priv->num_tscs = i;
436
437         if (!priv->num_tscs) {
438                 ret = -ENODEV;
439                 goto error_unregister;
440         }
441
442         rcar_thermal_irq_set(priv, true);
443
444         return 0;
445
446 error_unregister:
447         rcar_gen3_thermal_remove(pdev);
448
449         return ret;
450 }
451
452 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
453 {
454         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
455
456         rcar_thermal_irq_set(priv, false);
457
458         return 0;
459 }
460
461 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
462 {
463         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
464         unsigned int i;
465
466         for (i = 0; i < priv->num_tscs; i++) {
467                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
468
469                 priv->thermal_init(tsc);
470                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
471         }
472
473         rcar_thermal_irq_set(priv, true);
474
475         return 0;
476 }
477
478 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
479                          rcar_gen3_thermal_resume);
480
481 static struct platform_driver rcar_gen3_thermal_driver = {
482         .driver = {
483                 .name   = "rcar_gen3_thermal",
484                 .pm = &rcar_gen3_thermal_pm_ops,
485                 .of_match_table = rcar_gen3_thermal_dt_ids,
486         },
487         .probe          = rcar_gen3_thermal_probe,
488         .remove         = rcar_gen3_thermal_remove,
489 };
490 module_platform_driver(rcar_gen3_thermal_driver);
491
492 MODULE_LICENSE("GPL v2");
493 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
494 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");