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 */
66static 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 */
73struct equation_coefs {
74	int a1;
75	int b1;
76	int a2;
77	int b2;
78};
79
80struct 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
88struct 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
94static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
95					 u32 reg)
96{
97	return ioread32(tsc->base + reg);
98}
99
100static 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
134static 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
156static 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
166static 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
191static 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
205static 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
223static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
224	.get_temp	= rcar_gen3_thermal_get_temp,
225};
226
227static 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
236static 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
255static const struct soc_device_attribute r8a7795es1[] = {
256	{ .soc_id = "r8a7795", .revision = "ES1.*" },
257	{ /* sentinel */ }
258};
259
260static 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
285static 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
306static const int rcar_gen3_ths_tj_1 = 126;
307static const int rcar_gen3_ths_tj_1_m3_w = 116;
308static 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};
343MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
344
345static 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
358static void rcar_gen3_hwmon_action(void *data)
359{
360	struct thermal_zone_device *zone = data;
361
362	thermal_remove_hwmon_sysfs(zone);
363}
364
365static 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
477error_unregister:
478	rcar_gen3_thermal_remove(pdev);
479
480	return ret;
481}
482
483static 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
492static 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
509static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
510			 rcar_gen3_thermal_resume);
511
512static 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};
521module_platform_driver(rcar_gen3_thermal_driver);
522
523MODULE_LICENSE("GPL v2");
524MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
525MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
526