2 * R-Car THS/TSC thermal sensor driver
4 * Copyright (C) 2012 Renesas Solutions Corp.
5 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
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.
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.
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.
20 #include <linux/delay.h>
21 #include <linux/err.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>
39 struct rcar_thermal_priv {
49 static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
54 spin_lock_irqsave(&priv->lock, flags);
56 ret = ioread32(priv->base + reg);
58 spin_unlock_irqrestore(&priv->lock, flags);
63 #if 0 /* no user at this point */
64 static void rcar_thermal_write(struct rcar_thermal_priv *priv,
69 spin_lock_irqsave(&priv->lock, flags);
71 iowrite32(data, priv->base + reg);
73 spin_unlock_irqrestore(&priv->lock, flags);
77 static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
83 spin_lock_irqsave(&priv->lock, flags);
85 val = ioread32(priv->base + reg);
88 iowrite32(val, priv->base + reg);
90 spin_unlock_irqrestore(&priv->lock, flags);
94 * zone device functions
96 static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
99 struct rcar_thermal_priv *priv = zone->devdata;
100 int val, min, max, tmp;
102 tmp = -200; /* default */
104 if (priv->comp < 1 || priv->comp > 12) {
106 "THSSR invalid data (%d)\n", priv->comp);
107 priv->comp = 4; /* for next thermal */
112 * THS comparator offset and the reference temperature
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
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
132 /* calculate thermal limitation */
133 min = (priv->comp * 15) - 60;
137 * we need to wait 300us after changing comparator offset
138 * to get stable temperature.
139 * see "Usage Notes" on datasheet
141 rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp);
144 /* calculate current temperature */
145 val = rcar_thermal_read(priv, THSSR) & CTEMP;
146 val = (val * 5) - 65;
148 dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n",
149 priv->comp, min, max, val);
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.
162 priv->comp--; /* try again */
163 } else if (val >= max) {
165 priv->comp++; /* try again */
176 static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
177 .get_temp = rcar_thermal_get_temp,
183 static int rcar_thermal_probe(struct platform_device *pdev)
185 struct thermal_zone_device *zone;
186 struct rcar_thermal_priv *priv;
187 struct resource *res;
190 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
192 dev_err(&pdev->dev, "Could not get platform resource\n");
196 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
198 dev_err(&pdev->dev, "Could not allocate priv\n");
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));
208 dev_err(&pdev->dev, "Unable to ioremap thermal register\n");
210 goto error_free_priv;
213 zone = thermal_zone_device_register("rcar_thermal", 0, priv,
214 &rcar_thermal_zone_ops, 0, 0);
216 dev_err(&pdev->dev, "thermal zone device is NULL\n");
221 platform_set_drvdata(pdev, zone);
223 dev_info(&pdev->dev, "proved\n");
228 devm_iounmap(&pdev->dev, priv->base);
230 devm_kfree(&pdev->dev, priv);
235 static int rcar_thermal_remove(struct platform_device *pdev)
237 struct thermal_zone_device *zone = platform_get_drvdata(pdev);
238 struct rcar_thermal_priv *priv = zone->devdata;
240 thermal_zone_device_unregister(zone);
241 platform_set_drvdata(pdev, NULL);
243 devm_iounmap(&pdev->dev, priv->base);
244 devm_kfree(&pdev->dev, priv);
249 static struct platform_driver rcar_thermal_driver = {
251 .name = "rcar_thermal",
253 .probe = rcar_thermal_probe,
254 .remove = rcar_thermal_remove,
256 module_platform_driver(rcar_thermal_driver);
258 MODULE_LICENSE("GPL");
259 MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
260 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");