xref: /linux/drivers/thermal/renesas/rzg3e_thermal.c (revision 68a052239fc4b351e961f698b824f7654a346091)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas RZ/G3E TSU Temperature Sensor Unit
4  *
5  * Copyright (C) 2025 Renesas Electronics Corporation
6  */
7 #include <linux/clk.h>
8 #include <linux/cleanup.h>
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/iopoll.h>
14 #include <linux/kernel.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/regmap.h>
21 #include <linux/reset.h>
22 #include <linux/thermal.h>
23 #include <linux/units.h>
24 
25 #include "../thermal_hwmon.h"
26 
27 /* TSU Register offsets and bits */
28 #define TSU_SSUSR		0x00
29 #define TSU_SSUSR_EN_TS		BIT(0)
30 #define TSU_SSUSR_ADC_PD_TS	BIT(1)
31 #define TSU_SSUSR_SOC_TS_EN	BIT(2)
32 
33 #define TSU_STRGR		0x04
34 #define TSU_STRGR_ADST		BIT(0)
35 
36 #define TSU_SOSR1		0x08
37 #define TSU_SOSR1_ADCT_8	0x03
38 #define TSU_SOSR1_ADCS		BIT(4)
39 #define TSU_SOSR1_OUTSEL	BIT(9)
40 
41 #define TSU_SCRR		0x10
42 #define TSU_SCRR_OUT12BIT_TS	GENMASK(11, 0)
43 
44 #define TSU_SSR			0x14
45 #define TSU_SSR_CONV		BIT(0)
46 
47 #define TSU_CMSR		0x18
48 #define TSU_CMSR_CMPEN		BIT(0)
49 
50 #define TSU_LLSR		0x1C
51 #define TSU_ULSR		0x20
52 
53 #define TSU_SISR		0x30
54 #define TSU_SISR_ADF		BIT(0)
55 #define TSU_SISR_CMPF		BIT(1)
56 
57 #define TSU_SIER		0x34
58 #define TSU_SIER_CMPIE		BIT(1)
59 
60 #define TSU_SICR		0x38
61 #define TSU_SICR_ADCLR		BIT(0)
62 #define TSU_SICR_CMPCLR	BIT(1)
63 
64 /* Temperature calculation constants from datasheet */
65 #define TSU_TEMP_D		(-41)
66 #define TSU_TEMP_E		126
67 #define TSU_CODE_MAX		0xFFF
68 
69 /* Timing specifications from datasheet */
70 #define TSU_POWERUP_TIME_US	120	/* 120T at 1MHz sensor clock per datasheet */
71 #define TSU_CONV_TIME_US	50	/* Per sample conversion time */
72 #define TSU_POLL_DELAY_US	10	/* Polling interval */
73 #define TSU_MIN_CLOCK_RATE	24000000  /* TSU_PCLK minimum 24MHz */
74 
75 /**
76  * struct rzg3e_thermal_priv - RZ/G3E TSU private data
77  * @base: TSU register base
78  * @dev: device pointer
79  * @syscon: regmap for calibration values
80  * @zone: thermal zone device
81  * @rstc: reset control
82  * @trmval0: calibration value 0 (b)
83  * @trmval1: calibration value 1 (c)
84  * @trim_offset: offset for trim registers in syscon
85  * @lock: protects hardware access during conversions
86  */
87 struct rzg3e_thermal_priv {
88 	void __iomem *base;
89 	struct device *dev;
90 	struct regmap *syscon;
91 	struct thermal_zone_device *zone;
92 	struct reset_control *rstc;
93 	u16 trmval0;
94 	u16 trmval1;
95 	u32 trim_offset;
96 	struct mutex lock;
97 };
98 
99 static int rzg3e_thermal_power_on(struct rzg3e_thermal_priv *priv)
100 {
101 	u32 val;
102 	int ret;
103 
104 	/* Clear any pending interrupts */
105 	writel(TSU_SICR_ADCLR | TSU_SICR_CMPCLR, priv->base + TSU_SICR);
106 
107 	/* Disable all interrupts during setup */
108 	writel(0, priv->base + TSU_SIER);
109 
110 	/*
111 	 * Power-on sequence per datasheet 7.11.9.1:
112 	 * SOC_TS_EN must be set at same time or before EN_TS and ADC_PD_TS
113 	 */
114 	val = TSU_SSUSR_SOC_TS_EN | TSU_SSUSR_EN_TS;
115 	writel(val, priv->base + TSU_SSUSR);
116 
117 	/* Wait for sensor stabilization per datasheet 7.11.7.1 */
118 	usleep_range(TSU_POWERUP_TIME_US, TSU_POWERUP_TIME_US + 10);
119 
120 	/* Configure for average mode with 8 samples */
121 	val = TSU_SOSR1_OUTSEL | TSU_SOSR1_ADCT_8;
122 	writel(val, priv->base + TSU_SOSR1);
123 
124 	/* Ensure we're in single scan mode (default) */
125 	val = readl(priv->base + TSU_SOSR1);
126 	if (val & TSU_SOSR1_ADCS) {
127 		dev_err(priv->dev, "Invalid scan mode setting\n");
128 		return -EINVAL;
129 	}
130 
131 	/* Wait for any ongoing conversion to complete */
132 	ret = readl_poll_timeout(priv->base + TSU_SSR, val,
133 				 !(val & TSU_SSR_CONV),
134 				 TSU_POLL_DELAY_US,
135 				 USEC_PER_MSEC);
136 	if (ret) {
137 		dev_err(priv->dev, "Timeout waiting for conversion\n");
138 		return ret;
139 	}
140 
141 	return 0;
142 }
143 
144 static void rzg3e_thermal_power_off(struct rzg3e_thermal_priv *priv)
145 {
146 	/* Disable all interrupts */
147 	writel(0, priv->base + TSU_SIER);
148 
149 	/* Clear pending interrupts */
150 	writel(TSU_SICR_ADCLR | TSU_SICR_CMPCLR, priv->base + TSU_SICR);
151 
152 	/* Power down sequence per datasheet */
153 	writel(TSU_SSUSR_ADC_PD_TS, priv->base + TSU_SSUSR);
154 }
155 
156 /*
157  * Convert 12-bit sensor code to temperature in millicelsius
158  * Formula from datasheet 7.11.7.8:
159  * T(°C) = ((e - d) / (c - b)) * (a - b) + d
160  * where: a = sensor code, b = trmval0, c = trmval1, d = -41, e = 126
161  */
162 static int rzg3e_thermal_code_to_temp(struct rzg3e_thermal_priv *priv, u16 code)
163 {
164 	int temp_e_mc = TSU_TEMP_E * MILLIDEGREE_PER_DEGREE;
165 	int temp_d_mc = TSU_TEMP_D * MILLIDEGREE_PER_DEGREE;
166 	s64 numerator, denominator;
167 	int temp_mc;
168 
169 	numerator = (temp_e_mc - temp_d_mc) * (s64)(code - priv->trmval0);
170 	denominator = priv->trmval1 - priv->trmval0;
171 
172 	temp_mc = div64_s64(numerator, denominator) + temp_d_mc;
173 
174 	return clamp(temp_mc, temp_d_mc, temp_e_mc);
175 }
176 
177 /*
178  * Convert temperature in millicelsius to 12-bit sensor code
179  * Formula from datasheet 7.11.7.9 (inverse of above)
180  */
181 static u16 rzg3e_thermal_temp_to_code(struct rzg3e_thermal_priv *priv, int temp_mc)
182 {
183 	int temp_e_mc = TSU_TEMP_E * MILLIDEGREE_PER_DEGREE;
184 	int temp_d_mc = TSU_TEMP_D * MILLIDEGREE_PER_DEGREE;
185 	s64 numerator, denominator;
186 	s64 code;
187 
188 	numerator = (temp_mc - temp_d_mc) * (priv->trmval1 - priv->trmval0);
189 	denominator = temp_e_mc - temp_d_mc;
190 
191 	code = div64_s64(numerator, denominator) + priv->trmval0;
192 
193 	return clamp_val(code, 0, TSU_CODE_MAX);
194 }
195 
196 static int rzg3e_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
197 {
198 	struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(tz);
199 	u32 status, code;
200 	int ret, timeout;
201 
202 	ret = pm_runtime_resume_and_get(priv->dev);
203 	if (ret < 0)
204 		return ret;
205 
206 	guard(mutex)(&priv->lock);
207 
208 	/* Clear any previous conversion status */
209 	writel(TSU_SICR_ADCLR, priv->base + TSU_SICR);
210 
211 	/* Start single conversion */
212 	writel(TSU_STRGR_ADST, priv->base + TSU_STRGR);
213 
214 	/* Wait for conversion completion - 8 samples at ~50us each */
215 	timeout = TSU_CONV_TIME_US * 8 * 2;  /* Double for margin */
216 	ret = readl_poll_timeout(priv->base + TSU_SISR, status,
217 				 status & TSU_SISR_ADF,
218 				 TSU_POLL_DELAY_US, timeout);
219 	if (ret) {
220 		dev_err(priv->dev, "Conversion timeout (status=0x%08x)\n", status);
221 		goto out;
222 	}
223 
224 	/* Read the averaged result and clear the complete flag */
225 	code = readl(priv->base + TSU_SCRR) & TSU_SCRR_OUT12BIT_TS;
226 	writel(TSU_SICR_ADCLR, priv->base + TSU_SICR);
227 
228 	/* Convert to temperature */
229 	*temp = rzg3e_thermal_code_to_temp(priv, code);
230 
231 	dev_dbg(priv->dev, "temp=%d mC (%d.%03d°C), code=0x%03x\n",
232 		*temp, *temp / 1000, abs(*temp) % 1000, code);
233 
234 out:
235 	pm_runtime_mark_last_busy(priv->dev);
236 	pm_runtime_put_autosuspend(priv->dev);
237 	return ret;
238 }
239 
240 static int rzg3e_thermal_set_trips(struct thermal_zone_device *tz,
241 				   int low, int high)
242 {
243 	struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(tz);
244 	u16 low_code, high_code;
245 	u32 val;
246 	int ret;
247 
248 	/* Hardware requires low < high */
249 	if (low >= high)
250 		return -EINVAL;
251 
252 	ret = pm_runtime_resume_and_get(priv->dev);
253 	if (ret < 0)
254 		return ret;
255 
256 	guard(mutex)(&priv->lock);
257 
258 	/* Convert temperatures to codes */
259 	low_code = rzg3e_thermal_temp_to_code(priv, low);
260 	high_code = rzg3e_thermal_temp_to_code(priv, high);
261 
262 	dev_dbg(priv->dev, "set_trips: low=%d high=%d (codes: 0x%03x/0x%03x)\n",
263 		low, high, low_code, high_code);
264 
265 	/* Disable comparison during reconfiguration */
266 	writel(0, priv->base + TSU_SIER);
267 	writel(0, priv->base + TSU_CMSR);
268 
269 	/* Clear any pending comparison interrupts */
270 	writel(TSU_SICR_CMPCLR, priv->base + TSU_SICR);
271 
272 	/* Set trip points */
273 	writel(low_code, priv->base + TSU_LLSR);
274 	writel(high_code, priv->base + TSU_ULSR);
275 
276 	/*
277 	 * Ensure OUTSEL is set for comparison per datasheet 7.11.7.4
278 	 * Comparison uses averaged data
279 	 */
280 	val = readl(priv->base + TSU_SOSR1);
281 	val |= TSU_SOSR1_OUTSEL;
282 	writel(val, priv->base + TSU_SOSR1);
283 
284 	/* Enable comparison with "out of range" mode (CMPCOND=0) */
285 	writel(TSU_CMSR_CMPEN, priv->base + TSU_CMSR);
286 
287 	/* Unmask compare IRQ and start a conversion to evaluate window */
288 	writel(TSU_SIER_CMPIE, priv->base + TSU_SIER);
289 	writel(TSU_STRGR_ADST, priv->base + TSU_STRGR);
290 
291 	pm_runtime_mark_last_busy(priv->dev);
292 	pm_runtime_put_autosuspend(priv->dev);
293 
294 	return 0;
295 }
296 
297 static irqreturn_t rzg3e_thermal_irq_thread(int irq, void *data)
298 {
299 	struct rzg3e_thermal_priv *priv = data;
300 
301 	dev_dbg(priv->dev, "Temperature threshold crossed\n");
302 
303 	/* Notify thermal framework to re-evaluate trip points */
304 	thermal_zone_device_update(priv->zone, THERMAL_TRIP_VIOLATED);
305 
306 	return IRQ_HANDLED;
307 }
308 
309 static irqreturn_t rzg3e_thermal_irq(int irq, void *data)
310 {
311 	struct rzg3e_thermal_priv *priv = data;
312 	u32 status;
313 
314 	status = readl(priv->base + TSU_SISR);
315 
316 	/* Check if comparison interrupt occurred */
317 	if (status & TSU_SISR_CMPF) {
318 		/* Clear irq flag and disable interrupt until reconfigured */
319 		writel(TSU_SICR_CMPCLR, priv->base + TSU_SICR);
320 		writel(0, priv->base + TSU_SIER);
321 
322 		return IRQ_WAKE_THREAD;
323 	}
324 
325 	return IRQ_NONE;
326 }
327 
328 static const struct thermal_zone_device_ops rzg3e_tz_ops = {
329 	.get_temp = rzg3e_thermal_get_temp,
330 	.set_trips = rzg3e_thermal_set_trips,
331 };
332 
333 static int rzg3e_thermal_get_calibration(struct rzg3e_thermal_priv *priv)
334 {
335 	u32 val;
336 	int ret;
337 
338 	/* Read calibration values from syscon */
339 	ret = regmap_read(priv->syscon, priv->trim_offset, &val);
340 	if (ret)
341 		return ret;
342 	priv->trmval0 = val & GENMASK(11, 0);
343 
344 	ret = regmap_read(priv->syscon, priv->trim_offset + 4, &val);
345 	if (ret)
346 		return ret;
347 	priv->trmval1 = val & GENMASK(11, 0);
348 
349 	/* Validate calibration data */
350 	if (!priv->trmval0 || !priv->trmval1 ||
351 	    priv->trmval0 == priv->trmval1 ||
352 	    priv->trmval0 == 0xFFF || priv->trmval1 == 0xFFF) {
353 		dev_err(priv->dev, "Invalid calibration: b=0x%03x, c=0x%03x\n",
354 			priv->trmval0, priv->trmval1);
355 		return -EINVAL;
356 	}
357 
358 	dev_dbg(priv->dev, "Calibration: b=0x%03x (%u), c=0x%03x (%u)\n",
359 		priv->trmval0, priv->trmval0, priv->trmval1, priv->trmval1);
360 
361 	return 0;
362 }
363 
364 static int rzg3e_thermal_parse_dt(struct rzg3e_thermal_priv *priv)
365 {
366 	struct device_node *np = priv->dev->of_node;
367 	u32 offset;
368 
369 	priv->syscon = syscon_regmap_lookup_by_phandle_args(np, "renesas,tsu-trim", 1, &offset);
370 	if (IS_ERR(priv->syscon))
371 		return dev_err_probe(priv->dev, PTR_ERR(priv->syscon),
372 				     "Failed to parse renesas,tsu-trim\n");
373 
374 	priv->trim_offset = offset;
375 	return 0;
376 }
377 
378 static int rzg3e_thermal_probe(struct platform_device *pdev)
379 {
380 	struct device *dev = &pdev->dev;
381 	struct rzg3e_thermal_priv *priv;
382 	struct clk *clk;
383 	int irq, ret;
384 
385 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
386 	if (!priv)
387 		return -ENOMEM;
388 
389 	priv->dev = dev;
390 	ret = devm_mutex_init(dev, &priv->lock);
391 	if (ret)
392 		return ret;
393 	platform_set_drvdata(pdev, priv);
394 
395 	priv->base = devm_platform_ioremap_resource(pdev, 0);
396 	if (IS_ERR(priv->base))
397 		return PTR_ERR(priv->base);
398 
399 	/* Parse device tree for trim register info */
400 	ret = rzg3e_thermal_parse_dt(priv);
401 	if (ret)
402 		return ret;
403 
404 	/* Get clock to verify frequency - clock is managed by power domain */
405 	clk = devm_clk_get(dev, NULL);
406 	if (IS_ERR(clk))
407 		return dev_err_probe(dev, PTR_ERR(clk),
408 				     "Failed to get clock\n");
409 
410 	if (clk_get_rate(clk) < TSU_MIN_CLOCK_RATE)
411 		return dev_err_probe(dev, -EINVAL,
412 				     "Clock rate %lu Hz too low (min %u Hz)\n",
413 				     clk_get_rate(clk), TSU_MIN_CLOCK_RATE);
414 
415 	priv->rstc = devm_reset_control_get_exclusive_deasserted(dev, NULL);
416 	if (IS_ERR(priv->rstc))
417 		return dev_err_probe(dev, PTR_ERR(priv->rstc),
418 				     "Failed to get/deassert reset control\n");
419 
420 	/* Get calibration data */
421 	ret = rzg3e_thermal_get_calibration(priv);
422 	if (ret)
423 		return dev_err_probe(dev, ret,
424 				     "Failed to get valid calibration data\n");
425 
426 	/* Get comparison interrupt */
427 	irq = platform_get_irq_byname(pdev, "adcmpi");
428 	if (irq < 0)
429 		return irq;
430 
431 	/* Enable runtime PM */
432 	pm_runtime_set_autosuspend_delay(dev, 1000);
433 	pm_runtime_use_autosuspend(dev);
434 	devm_pm_runtime_enable(dev);
435 
436 	/* Initial hardware setup */
437 	ret = pm_runtime_resume_and_get(dev);
438 	if (ret < 0)
439 		return dev_err_probe(dev, ret, "Runtime resume failed\n");
440 
441 	/* Register thermal zone - this will trigger DT parsing */
442 	priv->zone = devm_thermal_of_zone_register(dev, 0, priv, &rzg3e_tz_ops);
443 	if (IS_ERR(priv->zone)) {
444 		ret = PTR_ERR(priv->zone);
445 		dev_err(dev, "Failed to register thermal zone: %d\n", ret);
446 		goto err_pm_put;
447 	}
448 
449 	/* Request threaded IRQ for comparison interrupt */
450 	ret = devm_request_threaded_irq(dev, irq, rzg3e_thermal_irq,
451 					rzg3e_thermal_irq_thread,
452 					IRQF_ONESHOT, "rzg3e_thermal", priv);
453 	if (ret) {
454 		dev_err(dev, "Failed to request IRQ: %d\n", ret);
455 		goto err_pm_put;
456 	}
457 
458 	/* Add hwmon sysfs interface */
459 	ret = devm_thermal_add_hwmon_sysfs(dev, priv->zone);
460 	if (ret)
461 		dev_warn(dev, "Failed to add hwmon sysfs attributes\n");
462 
463 	pm_runtime_mark_last_busy(dev);
464 	pm_runtime_put_autosuspend(dev);
465 
466 	dev_info(dev, "RZ/G3E thermal sensor registered\n");
467 
468 	return 0;
469 
470 err_pm_put:
471 	pm_runtime_put_sync(dev);
472 	return ret;
473 }
474 
475 static int rzg3e_thermal_runtime_suspend(struct device *dev)
476 {
477 	struct rzg3e_thermal_priv *priv = dev_get_drvdata(dev);
478 
479 	rzg3e_thermal_power_off(priv);
480 	return 0;
481 }
482 
483 static int rzg3e_thermal_runtime_resume(struct device *dev)
484 {
485 	struct rzg3e_thermal_priv *priv = dev_get_drvdata(dev);
486 
487 	return rzg3e_thermal_power_on(priv);
488 }
489 
490 static int rzg3e_thermal_suspend(struct device *dev)
491 {
492 	struct rzg3e_thermal_priv *priv = dev_get_drvdata(dev);
493 
494 	/* If device is active, power it off */
495 	if (pm_runtime_active(dev))
496 		rzg3e_thermal_power_off(priv);
497 
498 	/* Assert reset to ensure clean state after resume */
499 	reset_control_assert(priv->rstc);
500 
501 	return 0;
502 }
503 
504 static int rzg3e_thermal_resume(struct device *dev)
505 {
506 	struct rzg3e_thermal_priv *priv = dev_get_drvdata(dev);
507 	int ret;
508 
509 	/* Deassert reset */
510 	ret = reset_control_deassert(priv->rstc);
511 	if (ret) {
512 		dev_err(dev, "Failed to deassert reset: %d\n", ret);
513 		return ret;
514 	}
515 
516 	/* If device was active before suspend, power it back on */
517 	if (pm_runtime_active(dev))
518 		return rzg3e_thermal_power_on(priv);
519 
520 	return 0;
521 }
522 
523 static const struct dev_pm_ops rzg3e_thermal_pm_ops = {
524 	RUNTIME_PM_OPS(rzg3e_thermal_runtime_suspend,
525 		       rzg3e_thermal_runtime_resume, NULL)
526 	SYSTEM_SLEEP_PM_OPS(rzg3e_thermal_suspend, rzg3e_thermal_resume)
527 };
528 
529 static const struct of_device_id rzg3e_thermal_dt_ids[] = {
530 	{ .compatible = "renesas,r9a09g047-tsu" },
531 	{ /* sentinel */ }
532 };
533 MODULE_DEVICE_TABLE(of, rzg3e_thermal_dt_ids);
534 
535 static struct platform_driver rzg3e_thermal_driver = {
536 	.driver = {
537 		.name = "rzg3e_thermal",
538 		.of_match_table = rzg3e_thermal_dt_ids,
539 		.pm = pm_ptr(&rzg3e_thermal_pm_ops),
540 	},
541 	.probe = rzg3e_thermal_probe,
542 };
543 module_platform_driver(rzg3e_thermal_driver);
544 
545 MODULE_DESCRIPTION("Renesas RZ/G3E TSU Thermal Sensor Driver");
546 MODULE_AUTHOR("John Madieu <john.madieu.xa@bp.renesas.com>");
547 MODULE_LICENSE("GPL");
548