/*
* 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>");
