blob: f7a1b574a304e8808cb0cfda0d7e91ef6272bd50 [file] [log] [blame]
Kuninori Morimoto1e426ff2012-07-21 10:53:48 +10001/*
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/io.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26#include <linux/spinlock.h>
27#include <linux/thermal.h>
28
29#define THSCR 0x2c
30#define THSSR 0x30
31
32/* THSCR */
33#define CPTAP 0xf
34
35/* THSSR */
36#define CTEMP 0x3f
37
38
39struct rcar_thermal_priv {
40 void __iomem *base;
41 struct device *dev;
42 spinlock_t lock;
43 u32 comp;
44};
45
46/*
47 * basic functions
48 */
49static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
50{
51 unsigned long flags;
52 u32 ret;
53
54 spin_lock_irqsave(&priv->lock, flags);
55
56 ret = ioread32(priv->base + reg);
57
58 spin_unlock_irqrestore(&priv->lock, flags);
59
60 return ret;
61}
62
63#if 0 /* no user at this point */
64static void rcar_thermal_write(struct rcar_thermal_priv *priv,
65 u32 reg, u32 data)
66{
67 unsigned long flags;
68
69 spin_lock_irqsave(&priv->lock, flags);
70
71 iowrite32(data, priv->base + reg);
72
73 spin_unlock_irqrestore(&priv->lock, flags);
74}
75#endif
76
77static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
78 u32 mask, u32 data)
79{
80 unsigned long flags;
81 u32 val;
82
83 spin_lock_irqsave(&priv->lock, flags);
84
85 val = ioread32(priv->base + reg);
86 val &= ~mask;
87 val |= (data & mask);
88 iowrite32(val, priv->base + reg);
89
90 spin_unlock_irqrestore(&priv->lock, flags);
91}
92
93/*
94 * zone device functions
95 */
96static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
97 unsigned long *temp)
98{
99 struct rcar_thermal_priv *priv = zone->devdata;
100 int val, min, max, tmp;
101
102 tmp = -200; /* default */
103 while (1) {
104 if (priv->comp < 1 || priv->comp > 12) {
105 dev_err(priv->dev,
106 "THSSR invalid data (%d)\n", priv->comp);
107 priv->comp = 4; /* for next thermal */
108 return -EINVAL;
109 }
110
111 /*
112 * THS comparator offset and the reference temperature
113 *
114 * Comparator | reference | Temperature field
115 * offset | temperature | measurement
116 * | (degrees C) | (degrees C)
117 * -------------+---------------+-------------------
118 * 1 | -45 | -45 to -30
119 * 2 | -30 | -30 to -15
120 * 3 | -15 | -15 to 0
121 * 4 | 0 | 0 to +15
122 * 5 | +15 | +15 to +30
123 * 6 | +30 | +30 to +45
124 * 7 | +45 | +45 to +60
125 * 8 | +60 | +60 to +75
126 * 9 | +75 | +75 to +90
127 * 10 | +90 | +90 to +105
128 * 11 | +105 | +105 to +120
129 * 12 | +120 | +120 to +135
130 */
131
132 /* calculate thermal limitation */
133 min = (priv->comp * 15) - 60;
134 max = min + 15;
135
136 /*
137 * we need to wait 300us after changing comparator offset
138 * to get stable temperature.
139 * see "Usage Notes" on datasheet
140 */
141 rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp);
142 udelay(300);
143
144 /* calculate current temperature */
145 val = rcar_thermal_read(priv, THSSR) & CTEMP;
146 val = (val * 5) - 65;
147
148 dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n",
149 priv->comp, min, max, val);
150
151 /*
152 * If val is same as min/max, then,
153 * it should try again on next comparator.
154 * But the val might be correct temperature.
155 * Keep it on "tmp" and compare with next val.
156 */
157 if (tmp == val)
158 break;
159
160 if (val <= min) {
161 tmp = min;
162 priv->comp--; /* try again */
163 } else if (val >= max) {
164 tmp = max;
165 priv->comp++; /* try again */
166 } else {
167 tmp = val;
168 break;
169 }
170 }
171
172 *temp = tmp;
173 return 0;
174}
175
176static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
177 .get_temp = rcar_thermal_get_temp,
178};
179
180/*
181 * platform functions
182 */
183static int rcar_thermal_probe(struct platform_device *pdev)
184{
185 struct thermal_zone_device *zone;
186 struct rcar_thermal_priv *priv;
187 struct resource *res;
188 int ret;
189
190 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
191 if (!res) {
192 dev_err(&pdev->dev, "Could not get platform resource\n");
193 return -ENODEV;
194 }
195
196 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
197 if (!priv) {
198 dev_err(&pdev->dev, "Could not allocate priv\n");
199 return -ENOMEM;
200 }
201
202 priv->comp = 4; /* basic setup */
203 priv->dev = &pdev->dev;
204 spin_lock_init(&priv->lock);
205 priv->base = devm_ioremap_nocache(&pdev->dev,
206 res->start, resource_size(res));
207 if (!priv->base) {
208 dev_err(&pdev->dev, "Unable to ioremap thermal register\n");
209 ret = -ENOMEM;
210 goto error_free_priv;
211 }
212
Devendra Naga608f62b2012-10-31 17:46:10 +0900213 zone = thermal_zone_device_register("rcar_thermal", 0, 0, priv,
Kuninori Morimoto1e426ff2012-07-21 10:53:48 +1000214 &rcar_thermal_zone_ops, 0, 0);
215 if (IS_ERR(zone)) {
216 dev_err(&pdev->dev, "thermal zone device is NULL\n");
217 ret = PTR_ERR(zone);
218 goto error_iounmap;
219 }
220
221 platform_set_drvdata(pdev, zone);
222
223 dev_info(&pdev->dev, "proved\n");
224
225 return 0;
226
227error_iounmap:
228 devm_iounmap(&pdev->dev, priv->base);
229error_free_priv:
230 devm_kfree(&pdev->dev, priv);
231
232 return ret;
233}
234
235static int rcar_thermal_remove(struct platform_device *pdev)
236{
237 struct thermal_zone_device *zone = platform_get_drvdata(pdev);
238 struct rcar_thermal_priv *priv = zone->devdata;
239
240 thermal_zone_device_unregister(zone);
241 platform_set_drvdata(pdev, NULL);
242
243 devm_iounmap(&pdev->dev, priv->base);
244 devm_kfree(&pdev->dev, priv);
245
246 return 0;
247}
248
249static struct platform_driver rcar_thermal_driver = {
250 .driver = {
251 .name = "rcar_thermal",
252 },
253 .probe = rcar_thermal_probe,
254 .remove = rcar_thermal_remove,
255};
256module_platform_driver(rcar_thermal_driver);
257
258MODULE_LICENSE("GPL");
259MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
260MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");