aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/thermal/rcar_thermal.c
blob: 90db951725da46a7663264d94e2fa928a058e2dc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 *  R-Car THS/TSC thermal sensor driver
 *
 * Copyright (C) 2012 Renesas Solutions Corp.
 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 */
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/thermal.h>

#define THSCR	0x2c
#define THSSR	0x30

/* THSCR */
#define CPTAP	0xf

/* THSSR */
#define CTEMP	0x3f


struct rcar_thermal_priv {
	void __iomem *base;
	struct device *dev;
	spinlock_t lock;
	u32 comp;
};

#define MCELSIUS(temp)			((temp) * 1000)
#define rcar_zone_to_priv(zone)		(zone->devdata)

/*
 *		basic functions
 */
static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
{
	unsigned long flags;
	u32 ret;

	spin_lock_irqsave(&priv->lock, flags);

	ret = ioread32(priv->base + reg);

	spin_unlock_irqrestore(&priv->lock, flags);

	return ret;
}

#if 0 /* no user at this point */
static void rcar_thermal_write(struct rcar_thermal_priv *priv,
			       u32 reg, u32 data)
{
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);

	iowrite32(data, priv->base + reg);

	spin_unlock_irqrestore(&priv->lock, flags);
}
#endif

static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
			      u32 mask, u32 data)
{
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&priv->lock, flags);

	val = ioread32(priv->base + reg);
	val &= ~mask;
	val |= (data & mask);
	iowrite32(val, priv->base + reg);

	spin_unlock_irqrestore(&priv->lock, flags);
}

/*
 *		zone device functions
 */
static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
			   unsigned long *temp)
{
	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
	int val, min, max, tmp;

	tmp = -200; /* default */
	while (1) {
		if (priv->comp < 1 || priv->comp > 12) {
			dev_err(priv->dev,
				"THSSR invalid data (%d)\n", priv->comp);
			priv->comp = 4; /* for next thermal */
			return -EINVAL;
		}

		/*
		 * THS comparator offset and the reference temperature
		 *
		 * Comparator	| reference	| Temperature field
		 * offset	| temperature	| measurement
		 *		| (degrees C)	| (degrees C)
		 * -------------+---------------+-------------------
		 *  1		|  -45		|  -45 to  -30
		 *  2		|  -30		|  -30 to  -15
		 *  3		|  -15		|  -15 to    0
		 *  4		|    0		|    0 to  +15
		 *  5		|  +15		|  +15 to  +30
		 *  6		|  +30		|  +30 to  +45
		 *  7		|  +45		|  +45 to  +60
		 *  8		|  +60		|  +60 to  +75
		 *  9		|  +75		|  +75 to  +90
		 * 10		|  +90		|  +90 to +105
		 * 11		| +105		| +105 to +120
		 * 12		| +120		| +120 to +135
		 */

		/* calculate thermal limitation */
		min = (priv->comp * 15) - 60;
		max = min + 15;

		/*
		 * we need to wait 300us after changing comparator offset
		 * to get stable temperature.
		 * see "Usage Notes" on datasheet
		 */
		rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp);
		udelay(300);

		/* calculate current temperature */
		val = rcar_thermal_read(priv, THSSR) & CTEMP;
		val = (val * 5) - 65;

		dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n",
			priv->comp, min, max, val);

		/*
		 * If val is same as min/max, then,
		 * it should try again on next comparator.
		 * But the val might be correct temperature.
		 * Keep it on "tmp" and compare with next val.
		 */
		if (tmp == val)
			break;

		if (val <= min) {
			tmp = min;
			priv->comp--; /* try again */
		} else if (val >= max) {
			tmp = max;
			priv->comp++; /* try again */
		} else {
			tmp = val;
			break;
		}
	}

	*temp = MCELSIUS(tmp);
	return 0;
}

static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
	.get_temp = rcar_thermal_get_temp,
};

/*
 *		platform functions
 */
static int rcar_thermal_probe(struct platform_device *pdev)
{
	struct thermal_zone_device *zone;
	struct rcar_thermal_priv *priv;
	struct resource *res;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "Could not get platform resource\n");
		return -ENODEV;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		dev_err(&pdev->dev, "Could not allocate priv\n");
		return -ENOMEM;
	}

	priv->comp = 4; /* basic setup */
	priv->dev = &pdev->dev;
	spin_lock_init(&priv->lock);
	priv->base = devm_ioremap_nocache(&pdev->dev,
					  res->start, resource_size(res));
	if (!priv->base) {
		dev_err(&pdev->dev, "Unable to ioremap thermal register\n");
		return -ENOMEM;
	}

	zone = thermal_zone_device_register("rcar_thermal", 0, 0, priv,
				    &rcar_thermal_zone_ops, NULL, 0, 0);
	if (IS_ERR(zone)) {
		dev_err(&pdev->dev, "thermal zone device is NULL\n");
		return PTR_ERR(zone);
	}

	platform_set_drvdata(pdev, zone);

	dev_info(&pdev->dev, "proved\n");

	return 0;
}

static int rcar_thermal_remove(struct platform_device *pdev)
{
	struct thermal_zone_device *zone = platform_get_drvdata(pdev);

	thermal_zone_device_unregister(zone);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver rcar_thermal_driver = {
	.driver	= {
		.name	= "rcar_thermal",
	},
	.probe		= rcar_thermal_probe,
	.remove		= rcar_thermal_remove,
};
module_platform_driver(rcar_thermal_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");