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
{
46 #define MCELSIUS(temp) ((temp) * 1000)
47 #define rcar_zone_to_priv(zone) (zone->devdata)
52 static u32
rcar_thermal_read(struct rcar_thermal_priv
*priv
, u32 reg
)
57 spin_lock_irqsave(&priv
->lock
, flags
);
59 ret
= ioread32(priv
->base
+ reg
);
61 spin_unlock_irqrestore(&priv
->lock
, flags
);
66 #if 0 /* no user at this point */
67 static void rcar_thermal_write(struct rcar_thermal_priv
*priv
,
72 spin_lock_irqsave(&priv
->lock
, flags
);
74 iowrite32(data
, priv
->base
+ reg
);
76 spin_unlock_irqrestore(&priv
->lock
, flags
);
80 static void rcar_thermal_bset(struct rcar_thermal_priv
*priv
, u32 reg
,
86 spin_lock_irqsave(&priv
->lock
, flags
);
88 val
= ioread32(priv
->base
+ reg
);
91 iowrite32(val
, priv
->base
+ reg
);
93 spin_unlock_irqrestore(&priv
->lock
, flags
);
97 * zone device functions
99 static int rcar_thermal_get_temp(struct thermal_zone_device
*zone
,
102 struct rcar_thermal_priv
*priv
= rcar_zone_to_priv(zone
);
103 int val
, min
, max
, tmp
;
105 tmp
= -200; /* default */
107 if (priv
->comp
< 1 || priv
->comp
> 12) {
109 "THSSR invalid data (%d)\n", priv
->comp
);
110 priv
->comp
= 4; /* for next thermal */
115 * THS comparator offset and the reference temperature
117 * Comparator | reference | Temperature field
118 * offset | temperature | measurement
119 * | (degrees C) | (degrees C)
120 * -------------+---------------+-------------------
121 * 1 | -45 | -45 to -30
122 * 2 | -30 | -30 to -15
125 * 5 | +15 | +15 to +30
126 * 6 | +30 | +30 to +45
127 * 7 | +45 | +45 to +60
128 * 8 | +60 | +60 to +75
129 * 9 | +75 | +75 to +90
130 * 10 | +90 | +90 to +105
131 * 11 | +105 | +105 to +120
132 * 12 | +120 | +120 to +135
135 /* calculate thermal limitation */
136 min
= (priv
->comp
* 15) - 60;
140 * we need to wait 300us after changing comparator offset
141 * to get stable temperature.
142 * see "Usage Notes" on datasheet
144 rcar_thermal_bset(priv
, THSCR
, CPTAP
, priv
->comp
);
147 /* calculate current temperature */
148 val
= rcar_thermal_read(priv
, THSSR
) & CTEMP
;
149 val
= (val
* 5) - 65;
151 dev_dbg(priv
->dev
, "comp/min/max/val = %d/%d/%d/%d\n",
152 priv
->comp
, min
, max
, val
);
155 * If val is same as min/max, then,
156 * it should try again on next comparator.
157 * But the val might be correct temperature.
158 * Keep it on "tmp" and compare with next val.
165 priv
->comp
--; /* try again */
166 } else if (val
>= max
) {
168 priv
->comp
++; /* try again */
175 *temp
= MCELSIUS(tmp
);
179 static struct thermal_zone_device_ops rcar_thermal_zone_ops
= {
180 .get_temp
= rcar_thermal_get_temp
,
186 static int rcar_thermal_probe(struct platform_device
*pdev
)
188 struct thermal_zone_device
*zone
;
189 struct rcar_thermal_priv
*priv
;
190 struct resource
*res
;
192 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
194 dev_err(&pdev
->dev
, "Could not get platform resource\n");
198 priv
= devm_kzalloc(&pdev
->dev
, sizeof(*priv
), GFP_KERNEL
);
200 dev_err(&pdev
->dev
, "Could not allocate priv\n");
204 priv
->comp
= 4; /* basic setup */
205 priv
->dev
= &pdev
->dev
;
206 spin_lock_init(&priv
->lock
);
207 priv
->base
= devm_ioremap_nocache(&pdev
->dev
,
208 res
->start
, resource_size(res
));
210 dev_err(&pdev
->dev
, "Unable to ioremap thermal register\n");
214 zone
= thermal_zone_device_register("rcar_thermal", 0, 0, priv
,
215 &rcar_thermal_zone_ops
, NULL
, 0, 0);
217 dev_err(&pdev
->dev
, "thermal zone device is NULL\n");
218 return PTR_ERR(zone
);
221 platform_set_drvdata(pdev
, zone
);
223 dev_info(&pdev
->dev
, "proved\n");
228 static int rcar_thermal_remove(struct platform_device
*pdev
)
230 struct thermal_zone_device
*zone
= platform_get_drvdata(pdev
);
232 thermal_zone_device_unregister(zone
);
233 platform_set_drvdata(pdev
, NULL
);
238 static struct platform_driver rcar_thermal_driver
= {
240 .name
= "rcar_thermal",
242 .probe
= rcar_thermal_probe
,
243 .remove
= rcar_thermal_remove
,
245 module_platform_driver(rcar_thermal_driver
);
247 MODULE_LICENSE("GPL");
248 MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
249 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");