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
51struct rcar_thermal_common {
52	void __iomem *base;
53	struct device *dev;
54	struct list_head head;
55	spinlock_t lock;
56};
57
58struct 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#ifdef DEBUG
79# define rcar_force_update_temp(priv)	1
80#else
81# define rcar_force_update_temp(priv)	0
82#endif
83
84/*
85 *		basic functions
86 */
87#define rcar_thermal_common_read(c, r) \
88	_rcar_thermal_common_read(c, COMMON_ ##r)
89static 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)
97static 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)
105static 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)
117static 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)
123static 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)
130static 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 */
144static 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;
198err_out_unlock:
199	mutex_unlock(&priv->lock);
200	return ret;
201}
202
203static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
204				 unsigned long *temp)
205{
206	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
207
208	if (!rcar_has_irq_support(priv) || rcar_force_update_temp(priv))
209		rcar_thermal_update_temp(priv);
210
211	mutex_lock(&priv->lock);
212	*temp =  MCELSIUS((priv->ctemp * 5) - 65);
213	mutex_unlock(&priv->lock);
214
215	return 0;
216}
217
218static int rcar_thermal_get_trip_type(struct thermal_zone_device *zone,
219				      int trip, enum thermal_trip_type *type)
220{
221	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
222	struct device *dev = rcar_priv_to_dev(priv);
223
224	/* see rcar_thermal_get_temp() */
225	switch (trip) {
226	case 0: /* +90 <= temp */
227		*type = THERMAL_TRIP_CRITICAL;
228		break;
229	default:
230		dev_err(dev, "rcar driver trip error\n");
231		return -EINVAL;
232	}
233
234	return 0;
235}
236
237static int rcar_thermal_get_trip_temp(struct thermal_zone_device *zone,
238				      int trip, unsigned long *temp)
239{
240	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
241	struct device *dev = rcar_priv_to_dev(priv);
242
243	/* see rcar_thermal_get_temp() */
244	switch (trip) {
245	case 0: /* +90 <= temp */
246		*temp = MCELSIUS(90);
247		break;
248	default:
249		dev_err(dev, "rcar driver trip error\n");
250		return -EINVAL;
251	}
252
253	return 0;
254}
255
256static int rcar_thermal_notify(struct thermal_zone_device *zone,
257			       int trip, enum thermal_trip_type type)
258{
259	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
260	struct device *dev = rcar_priv_to_dev(priv);
261
262	switch (type) {
263	case THERMAL_TRIP_CRITICAL:
264		/* FIXME */
265		dev_warn(dev, "Thermal reached to critical temperature\n");
266		break;
267	default:
268		break;
269	}
270
271	return 0;
272}
273
274static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
275	.get_temp	= rcar_thermal_get_temp,
276	.get_trip_type	= rcar_thermal_get_trip_type,
277	.get_trip_temp	= rcar_thermal_get_trip_temp,
278	.notify		= rcar_thermal_notify,
279};
280
281/*
282 *		interrupt
283 */
284#define rcar_thermal_irq_enable(p)	_rcar_thermal_irq_ctrl(p, 1)
285#define rcar_thermal_irq_disable(p)	_rcar_thermal_irq_ctrl(p, 0)
286static void _rcar_thermal_irq_ctrl(struct rcar_thermal_priv *priv, int enable)
287{
288	struct rcar_thermal_common *common = priv->common;
289	unsigned long flags;
290	u32 mask = 0x3 << rcar_id_to_shift(priv); /* enable Rising/Falling */
291
292	spin_lock_irqsave(&common->lock, flags);
293
294	rcar_thermal_common_bset(common, INTMSK, mask, enable ? 0 : mask);
295
296	spin_unlock_irqrestore(&common->lock, flags);
297}
298
299static void rcar_thermal_work(struct work_struct *work)
300{
301	struct rcar_thermal_priv *priv;
302	unsigned long cctemp, nctemp;
303
304	priv = container_of(work, struct rcar_thermal_priv, work.work);
305
306	rcar_thermal_get_temp(priv->zone, &cctemp);
307	rcar_thermal_update_temp(priv);
308	rcar_thermal_irq_enable(priv);
309
310	rcar_thermal_get_temp(priv->zone, &nctemp);
311	if (nctemp != cctemp)
312		thermal_zone_device_update(priv->zone);
313}
314
315static u32 rcar_thermal_had_changed(struct rcar_thermal_priv *priv, u32 status)
316{
317	struct device *dev = rcar_priv_to_dev(priv);
318
319	status = (status >> rcar_id_to_shift(priv)) & 0x3;
320
321	if (status) {
322		dev_dbg(dev, "thermal%d %s%s\n",
323			priv->id,
324			(status & 0x2) ? "Rising " : "",
325			(status & 0x1) ? "Falling" : "");
326	}
327
328	return status;
329}
330
331static irqreturn_t rcar_thermal_irq(int irq, void *data)
332{
333	struct rcar_thermal_common *common = data;
334	struct rcar_thermal_priv *priv;
335	unsigned long flags;
336	u32 status, mask;
337
338	spin_lock_irqsave(&common->lock, flags);
339
340	mask	= rcar_thermal_common_read(common, INTMSK);
341	status	= rcar_thermal_common_read(common, STR);
342	rcar_thermal_common_write(common, STR, 0x000F0F0F & mask);
343
344	spin_unlock_irqrestore(&common->lock, flags);
345
346	status = status & ~mask;
347
348	/*
349	 * check the status
350	 */
351	rcar_thermal_for_each_priv(priv, common) {
352		if (rcar_thermal_had_changed(priv, status)) {
353			rcar_thermal_irq_disable(priv);
354			schedule_delayed_work(&priv->work,
355					      msecs_to_jiffies(300));
356		}
357	}
358
359	return IRQ_HANDLED;
360}
361
362/*
363 *		platform functions
364 */
365static int rcar_thermal_probe(struct platform_device *pdev)
366{
367	struct rcar_thermal_common *common;
368	struct rcar_thermal_priv *priv;
369	struct device *dev = &pdev->dev;
370	struct resource *res, *irq;
371	int mres = 0;
372	int i;
373	int ret = -ENODEV;
374	int idle = IDLE_INTERVAL;
375	u32 enr_bits = 0;
376
377	common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
378	if (!common)
379		return -ENOMEM;
380
381	INIT_LIST_HEAD(&common->head);
382	spin_lock_init(&common->lock);
383	common->dev = dev;
384
385	pm_runtime_enable(dev);
386	pm_runtime_get_sync(dev);
387
388	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
389	if (irq) {
390		/*
391		 * platform has IRQ support.
392		 * Then, driver uses common registers
393		 * rcar_has_irq_support() will be enabled
394		 */
395		res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
396		common->base = devm_ioremap_resource(dev, res);
397		if (IS_ERR(common->base))
398			return PTR_ERR(common->base);
399
400		idle = 0; /* polling delay is not needed */
401	}
402
403	for (i = 0;; i++) {
404		res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
405		if (!res)
406			break;
407
408		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
409		if (!priv) {
410			ret = -ENOMEM;
411			goto error_unregister;
412		}
413
414		priv->base = devm_ioremap_resource(dev, res);
415		if (IS_ERR(priv->base)) {
416			ret = PTR_ERR(priv->base);
417			goto error_unregister;
418		}
419
420		priv->common = common;
421		priv->id = i;
422		mutex_init(&priv->lock);
423		INIT_LIST_HEAD(&priv->list);
424		INIT_DELAYED_WORK(&priv->work, rcar_thermal_work);
425		rcar_thermal_update_temp(priv);
426
427		priv->zone = thermal_zone_device_register("rcar_thermal",
428						1, 0, priv,
429						&rcar_thermal_zone_ops, NULL, 0,
430						idle);
431		if (IS_ERR(priv->zone)) {
432			dev_err(dev, "can't register thermal zone\n");
433			ret = PTR_ERR(priv->zone);
434			goto error_unregister;
435		}
436
437		if (rcar_has_irq_support(priv))
438			rcar_thermal_irq_enable(priv);
439
440		list_move_tail(&priv->list, &common->head);
441
442		/* update ENR bits */
443		enr_bits |= 3 << (i * 8);
444	}
445
446	/* enable temperature comparation */
447	if (irq) {
448		ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
449				       dev_name(dev), common);
450		if (ret) {
451			dev_err(dev, "irq request failed\n ");
452			goto error_unregister;
453		}
454
455		rcar_thermal_common_write(common, ENR, enr_bits);
456	}
457
458	platform_set_drvdata(pdev, common);
459
460	dev_info(dev, "%d sensor probed\n", i);
461
462	return 0;
463
464error_unregister:
465	rcar_thermal_for_each_priv(priv, common) {
466		if (rcar_has_irq_support(priv))
467			rcar_thermal_irq_disable(priv);
468		thermal_zone_device_unregister(priv->zone);
469	}
470
471	pm_runtime_put(dev);
472	pm_runtime_disable(dev);
473
474	return ret;
475}
476
477static int rcar_thermal_remove(struct platform_device *pdev)
478{
479	struct rcar_thermal_common *common = platform_get_drvdata(pdev);
480	struct device *dev = &pdev->dev;
481	struct rcar_thermal_priv *priv;
482
483	rcar_thermal_for_each_priv(priv, common) {
484		if (rcar_has_irq_support(priv))
485			rcar_thermal_irq_disable(priv);
486		thermal_zone_device_unregister(priv->zone);
487	}
488
489	pm_runtime_put(dev);
490	pm_runtime_disable(dev);
491
492	return 0;
493}
494
495static const struct of_device_id rcar_thermal_dt_ids[] = {
496	{ .compatible = "renesas,rcar-thermal", },
497	{},
498};
499MODULE_DEVICE_TABLE(of, rcar_thermal_dt_ids);
500
501static struct platform_driver rcar_thermal_driver = {
502	.driver	= {
503		.name	= "rcar_thermal",
504		.of_match_table = rcar_thermal_dt_ids,
505	},
506	.probe		= rcar_thermal_probe,
507	.remove		= rcar_thermal_remove,
508};
509module_platform_driver(rcar_thermal_driver);
510
511MODULE_LICENSE("GPL");
512MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
513MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
514