1 /*
2  *  R-Car THS/TSC thermal sensor driver
3  *
4  * Copyright (C) 2012 Renesas Solutions Corp.
5  * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; version 2 of the License.
10  *
11  *  This program is distributed in the hope that it will be useful, but
12  *  WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  *  General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License along
17  *  with this program; if not, write to the Free Software Foundation, Inc.,
18  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19  */
20 #include <linux/delay.h>
21 #include <linux/err.h>
22 #include <linux/irq.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/reboot.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/thermal.h>
32 
33 #define IDLE_INTERVAL	5000
34 
35 #define COMMON_STR	0x00
36 #define COMMON_ENR	0x04
37 #define COMMON_INTMSK	0x0c
38 
39 #define REG_POSNEG	0x20
40 #define REG_FILONOFF	0x28
41 #define REG_THSCR	0x2c
42 #define REG_THSSR	0x30
43 #define REG_INTCTRL	0x34
44 
45 /* THSCR */
46 #define CPCTL	(1 << 12)
47 
48 /* THSSR */
49 #define CTEMP	0x3f
50 
51 struct rcar_thermal_common {
52 	void __iomem *base;
53 	struct device *dev;
54 	struct list_head head;
55 	spinlock_t lock;
56 };
57 
58 struct rcar_thermal_priv {
59 	void __iomem *base;
60 	struct rcar_thermal_common *common;
61 	struct thermal_zone_device *zone;
62 	struct delayed_work work;
63 	struct mutex lock;
64 	struct list_head list;
65 	int id;
66 	u32 ctemp;
67 };
68 
69 #define rcar_thermal_for_each_priv(pos, common)	\
70 	list_for_each_entry(pos, &common->head, list)
71 
72 #define MCELSIUS(temp)			((temp) * 1000)
73 #define rcar_zone_to_priv(zone)		((zone)->devdata)
74 #define rcar_priv_to_dev(priv)		((priv)->common->dev)
75 #define rcar_has_irq_support(priv)	((priv)->common->base)
76 #define rcar_id_to_shift(priv)		((priv)->id * 8)
77 
78 static const struct of_device_id rcar_thermal_dt_ids[] = {
79 	{ .compatible = "renesas,rcar-thermal", },
80 	{},
81 };
82 MODULE_DEVICE_TABLE(of, rcar_thermal_dt_ids);
83 
84 /*
85  *		basic functions
86  */
87 #define rcar_thermal_common_read(c, r) \
88 	_rcar_thermal_common_read(c, COMMON_ ##r)
89 static u32 _rcar_thermal_common_read(struct rcar_thermal_common *common,
90 				     u32 reg)
91 {
92 	return ioread32(common->base + reg);
93 }
94 
95 #define rcar_thermal_common_write(c, r, d) \
96 	_rcar_thermal_common_write(c, COMMON_ ##r, d)
97 static void _rcar_thermal_common_write(struct rcar_thermal_common *common,
98 				       u32 reg, u32 data)
99 {
100 	iowrite32(data, common->base + reg);
101 }
102 
103 #define rcar_thermal_common_bset(c, r, m, d) \
104 	_rcar_thermal_common_bset(c, COMMON_ ##r, m, d)
105 static void _rcar_thermal_common_bset(struct rcar_thermal_common *common,
106 				      u32 reg, u32 mask, u32 data)
107 {
108 	u32 val;
109 
110 	val = ioread32(common->base + reg);
111 	val &= ~mask;
112 	val |= (data & mask);
113 	iowrite32(val, common->base + reg);
114 }
115 
116 #define rcar_thermal_read(p, r) _rcar_thermal_read(p, REG_ ##r)
117 static u32 _rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
118 {
119 	return ioread32(priv->base + reg);
120 }
121 
122 #define rcar_thermal_write(p, r, d) _rcar_thermal_write(p, REG_ ##r, d)
123 static void _rcar_thermal_write(struct rcar_thermal_priv *priv,
124 				u32 reg, u32 data)
125 {
126 	iowrite32(data, priv->base + reg);
127 }
128 
129 #define rcar_thermal_bset(p, r, m, d) _rcar_thermal_bset(p, REG_ ##r, m, d)
130 static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
131 			       u32 mask, u32 data)
132 {
133 	u32 val;
134 
135 	val = ioread32(priv->base + reg);
136 	val &= ~mask;
137 	val |= (data & mask);
138 	iowrite32(val, priv->base + reg);
139 }
140 
141 /*
142  *		zone device functions
143  */
144 static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
145 {
146 	struct device *dev = rcar_priv_to_dev(priv);
147 	int i;
148 	u32 ctemp, old, new;
149 	int ret = -EINVAL;
150 
151 	mutex_lock(&priv->lock);
152 
153 	/*
154 	 * TSC decides a value of CPTAP automatically,
155 	 * and this is the conditions which validate interrupt.
156 	 */
157 	rcar_thermal_bset(priv, THSCR, CPCTL, CPCTL);
158 
159 	ctemp = 0;
160 	old = ~0;
161 	for (i = 0; i < 128; i++) {
162 		/*
163 		 * we need to wait 300us after changing comparator offset
164 		 * to get stable temperature.
165 		 * see "Usage Notes" on datasheet
166 		 */
167 		udelay(300);
168 
169 		new = rcar_thermal_read(priv, THSSR) & CTEMP;
170 		if (new == old) {
171 			ctemp = new;
172 			break;
173 		}
174 		old = new;
175 	}
176 
177 	if (!ctemp) {
178 		dev_err(dev, "thermal sensor was broken\n");
179 		goto err_out_unlock;
180 	}
181 
182 	/*
183 	 * enable IRQ
184 	 */
185 	if (rcar_has_irq_support(priv)) {
186 		rcar_thermal_write(priv, FILONOFF, 0);
187 
188 		/* enable Rising/Falling edge interrupt */
189 		rcar_thermal_write(priv, POSNEG,  0x1);
190 		rcar_thermal_write(priv, INTCTRL, (((ctemp - 0) << 8) |
191 						   ((ctemp - 1) << 0)));
192 	}
193 
194 	dev_dbg(dev, "thermal%d  %d -> %d\n", priv->id, priv->ctemp, ctemp);
195 
196 	priv->ctemp = ctemp;
197 	ret = 0;
198 err_out_unlock:
199 	mutex_unlock(&priv->lock);
200 	return ret;
201 }
202 
203 static int rcar_thermal_get_temp(struct thermal_zone_device *zone, int *temp)
204 {
205 	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
206 	int tmp;
207 	int ret;
208 
209 	ret = rcar_thermal_update_temp(priv);
210 	if (ret < 0)
211 		return ret;
212 
213 	mutex_lock(&priv->lock);
214 	tmp =  MCELSIUS((priv->ctemp * 5) - 65);
215 	mutex_unlock(&priv->lock);
216 
217 	if ((tmp < MCELSIUS(-45)) || (tmp > MCELSIUS(125))) {
218 		struct device *dev = rcar_priv_to_dev(priv);
219 
220 		dev_err(dev, "it couldn't measure temperature correctly\n");
221 		return -EIO;
222 	}
223 
224 	*temp = tmp;
225 
226 	return 0;
227 }
228 
229 static int rcar_thermal_get_trip_type(struct thermal_zone_device *zone,
230 				      int trip, enum thermal_trip_type *type)
231 {
232 	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
233 	struct device *dev = rcar_priv_to_dev(priv);
234 
235 	/* see rcar_thermal_get_temp() */
236 	switch (trip) {
237 	case 0: /* +90 <= temp */
238 		*type = THERMAL_TRIP_CRITICAL;
239 		break;
240 	default:
241 		dev_err(dev, "rcar driver trip error\n");
242 		return -EINVAL;
243 	}
244 
245 	return 0;
246 }
247 
248 static int rcar_thermal_get_trip_temp(struct thermal_zone_device *zone,
249 				      int trip, int *temp)
250 {
251 	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
252 	struct device *dev = rcar_priv_to_dev(priv);
253 
254 	/* see rcar_thermal_get_temp() */
255 	switch (trip) {
256 	case 0: /* +90 <= temp */
257 		*temp = MCELSIUS(90);
258 		break;
259 	default:
260 		dev_err(dev, "rcar driver trip error\n");
261 		return -EINVAL;
262 	}
263 
264 	return 0;
265 }
266 
267 static int rcar_thermal_notify(struct thermal_zone_device *zone,
268 			       int trip, enum thermal_trip_type type)
269 {
270 	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
271 	struct device *dev = rcar_priv_to_dev(priv);
272 
273 	switch (type) {
274 	case THERMAL_TRIP_CRITICAL:
275 		/* FIXME */
276 		dev_warn(dev, "Thermal reached to critical temperature\n");
277 		break;
278 	default:
279 		break;
280 	}
281 
282 	return 0;
283 }
284 
285 static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
286 	.get_temp	= rcar_thermal_get_temp,
287 	.get_trip_type	= rcar_thermal_get_trip_type,
288 	.get_trip_temp	= rcar_thermal_get_trip_temp,
289 	.notify		= rcar_thermal_notify,
290 };
291 
292 /*
293  *		interrupt
294  */
295 #define rcar_thermal_irq_enable(p)	_rcar_thermal_irq_ctrl(p, 1)
296 #define rcar_thermal_irq_disable(p)	_rcar_thermal_irq_ctrl(p, 0)
297 static void _rcar_thermal_irq_ctrl(struct rcar_thermal_priv *priv, int enable)
298 {
299 	struct rcar_thermal_common *common = priv->common;
300 	unsigned long flags;
301 	u32 mask = 0x3 << rcar_id_to_shift(priv); /* enable Rising/Falling */
302 
303 	if (!rcar_has_irq_support(priv))
304 		return;
305 
306 	spin_lock_irqsave(&common->lock, flags);
307 
308 	rcar_thermal_common_bset(common, INTMSK, mask, enable ? 0 : mask);
309 
310 	spin_unlock_irqrestore(&common->lock, flags);
311 }
312 
313 static void rcar_thermal_work(struct work_struct *work)
314 {
315 	struct rcar_thermal_priv *priv;
316 	int cctemp, nctemp;
317 	int ret;
318 
319 	priv = container_of(work, struct rcar_thermal_priv, work.work);
320 
321 	rcar_thermal_get_temp(priv->zone, &cctemp);
322 	ret = rcar_thermal_update_temp(priv);
323 	if (ret < 0)
324 		return;
325 
326 	rcar_thermal_irq_enable(priv);
327 
328 	rcar_thermal_get_temp(priv->zone, &nctemp);
329 	if (nctemp != cctemp)
330 		thermal_zone_device_update(priv->zone);
331 }
332 
333 static u32 rcar_thermal_had_changed(struct rcar_thermal_priv *priv, u32 status)
334 {
335 	struct device *dev = rcar_priv_to_dev(priv);
336 
337 	status = (status >> rcar_id_to_shift(priv)) & 0x3;
338 
339 	if (status) {
340 		dev_dbg(dev, "thermal%d %s%s\n",
341 			priv->id,
342 			(status & 0x2) ? "Rising " : "",
343 			(status & 0x1) ? "Falling" : "");
344 	}
345 
346 	return status;
347 }
348 
349 static irqreturn_t rcar_thermal_irq(int irq, void *data)
350 {
351 	struct rcar_thermal_common *common = data;
352 	struct rcar_thermal_priv *priv;
353 	unsigned long flags;
354 	u32 status, mask;
355 
356 	spin_lock_irqsave(&common->lock, flags);
357 
358 	mask	= rcar_thermal_common_read(common, INTMSK);
359 	status	= rcar_thermal_common_read(common, STR);
360 	rcar_thermal_common_write(common, STR, 0x000F0F0F & mask);
361 
362 	spin_unlock_irqrestore(&common->lock, flags);
363 
364 	status = status & ~mask;
365 
366 	/*
367 	 * check the status
368 	 */
369 	rcar_thermal_for_each_priv(priv, common) {
370 		if (rcar_thermal_had_changed(priv, status)) {
371 			rcar_thermal_irq_disable(priv);
372 			schedule_delayed_work(&priv->work,
373 					      msecs_to_jiffies(300));
374 		}
375 	}
376 
377 	return IRQ_HANDLED;
378 }
379 
380 /*
381  *		platform functions
382  */
383 static int rcar_thermal_remove(struct platform_device *pdev)
384 {
385 	struct rcar_thermal_common *common = platform_get_drvdata(pdev);
386 	struct device *dev = &pdev->dev;
387 	struct rcar_thermal_priv *priv;
388 
389 	rcar_thermal_for_each_priv(priv, common) {
390 		rcar_thermal_irq_disable(priv);
391 		thermal_zone_device_unregister(priv->zone);
392 	}
393 
394 	pm_runtime_put(dev);
395 	pm_runtime_disable(dev);
396 
397 	return 0;
398 }
399 
400 static int rcar_thermal_probe(struct platform_device *pdev)
401 {
402 	struct rcar_thermal_common *common;
403 	struct rcar_thermal_priv *priv;
404 	struct device *dev = &pdev->dev;
405 	struct resource *res, *irq;
406 	int mres = 0;
407 	int i;
408 	int ret = -ENODEV;
409 	int idle = IDLE_INTERVAL;
410 	u32 enr_bits = 0;
411 
412 	common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
413 	if (!common)
414 		return -ENOMEM;
415 
416 	platform_set_drvdata(pdev, common);
417 
418 	INIT_LIST_HEAD(&common->head);
419 	spin_lock_init(&common->lock);
420 	common->dev = dev;
421 
422 	pm_runtime_enable(dev);
423 	pm_runtime_get_sync(dev);
424 
425 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
426 	if (irq) {
427 		/*
428 		 * platform has IRQ support.
429 		 * Then, driver uses common registers
430 		 * rcar_has_irq_support() will be enabled
431 		 */
432 		res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
433 		common->base = devm_ioremap_resource(dev, res);
434 		if (IS_ERR(common->base))
435 			return PTR_ERR(common->base);
436 
437 		idle = 0; /* polling delay is not needed */
438 	}
439 
440 	for (i = 0;; i++) {
441 		res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
442 		if (!res)
443 			break;
444 
445 		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
446 		if (!priv) {
447 			ret = -ENOMEM;
448 			goto error_unregister;
449 		}
450 
451 		priv->base = devm_ioremap_resource(dev, res);
452 		if (IS_ERR(priv->base)) {
453 			ret = PTR_ERR(priv->base);
454 			goto error_unregister;
455 		}
456 
457 		priv->common = common;
458 		priv->id = i;
459 		mutex_init(&priv->lock);
460 		INIT_LIST_HEAD(&priv->list);
461 		INIT_DELAYED_WORK(&priv->work, rcar_thermal_work);
462 		ret = rcar_thermal_update_temp(priv);
463 		if (ret < 0)
464 			goto error_unregister;
465 
466 		priv->zone = thermal_zone_device_register("rcar_thermal",
467 						1, 0, priv,
468 						&rcar_thermal_zone_ops, NULL, 0,
469 						idle);
470 		if (IS_ERR(priv->zone)) {
471 			dev_err(dev, "can't register thermal zone\n");
472 			ret = PTR_ERR(priv->zone);
473 			goto error_unregister;
474 		}
475 
476 		rcar_thermal_irq_enable(priv);
477 
478 		list_move_tail(&priv->list, &common->head);
479 
480 		/* update ENR bits */
481 		enr_bits |= 3 << (i * 8);
482 	}
483 
484 	/* enable temperature comparation */
485 	if (irq) {
486 		ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
487 				       dev_name(dev), common);
488 		if (ret) {
489 			dev_err(dev, "irq request failed\n ");
490 			goto error_unregister;
491 		}
492 
493 		rcar_thermal_common_write(common, ENR, enr_bits);
494 	}
495 
496 	dev_info(dev, "%d sensor probed\n", i);
497 
498 	return 0;
499 
500 error_unregister:
501 	rcar_thermal_remove(pdev);
502 
503 	return ret;
504 }
505 
506 static struct platform_driver rcar_thermal_driver = {
507 	.driver	= {
508 		.name	= "rcar_thermal",
509 		.of_match_table = rcar_thermal_dt_ids,
510 	},
511 	.probe		= rcar_thermal_probe,
512 	.remove		= rcar_thermal_remove,
513 };
514 module_platform_driver(rcar_thermal_driver);
515 
516 MODULE_LICENSE("GPL");
517 MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
518 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
519