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261 lines
6 KiB
C
261 lines
6 KiB
C
![]() |
/*
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* R-Car THS/TSC thermal sensor driver
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*
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* Copyright (C) 2012 Renesas Solutions Corp.
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* Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*/
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/thermal.h>
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#define THSCR 0x2c
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#define THSSR 0x30
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/* THSCR */
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#define CPTAP 0xf
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/* THSSR */
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#define CTEMP 0x3f
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struct rcar_thermal_priv {
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void __iomem *base;
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struct device *dev;
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spinlock_t lock;
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u32 comp;
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};
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/*
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* basic functions
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*/
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static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
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{
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unsigned long flags;
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u32 ret;
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spin_lock_irqsave(&priv->lock, flags);
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ret = ioread32(priv->base + reg);
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spin_unlock_irqrestore(&priv->lock, flags);
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return ret;
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}
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#if 0 /* no user at this point */
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static void rcar_thermal_write(struct rcar_thermal_priv *priv,
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u32 reg, u32 data)
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{
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unsigned long flags;
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spin_lock_irqsave(&priv->lock, flags);
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iowrite32(data, priv->base + reg);
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spin_unlock_irqrestore(&priv->lock, flags);
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}
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#endif
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static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
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u32 mask, u32 data)
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{
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unsigned long flags;
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u32 val;
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spin_lock_irqsave(&priv->lock, flags);
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val = ioread32(priv->base + reg);
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val &= ~mask;
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val |= (data & mask);
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iowrite32(val, priv->base + reg);
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spin_unlock_irqrestore(&priv->lock, flags);
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}
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/*
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* zone device functions
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*/
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static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
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unsigned long *temp)
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{
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struct rcar_thermal_priv *priv = zone->devdata;
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int val, min, max, tmp;
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tmp = -200; /* default */
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while (1) {
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if (priv->comp < 1 || priv->comp > 12) {
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dev_err(priv->dev,
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"THSSR invalid data (%d)\n", priv->comp);
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priv->comp = 4; /* for next thermal */
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return -EINVAL;
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}
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/*
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* THS comparator offset and the reference temperature
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*
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* Comparator | reference | Temperature field
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* offset | temperature | measurement
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* | (degrees C) | (degrees C)
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* -------------+---------------+-------------------
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* 1 | -45 | -45 to -30
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* 2 | -30 | -30 to -15
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* 3 | -15 | -15 to 0
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* 4 | 0 | 0 to +15
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* 5 | +15 | +15 to +30
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* 6 | +30 | +30 to +45
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* 7 | +45 | +45 to +60
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* 8 | +60 | +60 to +75
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* 9 | +75 | +75 to +90
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* 10 | +90 | +90 to +105
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* 11 | +105 | +105 to +120
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* 12 | +120 | +120 to +135
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*/
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/* calculate thermal limitation */
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min = (priv->comp * 15) - 60;
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max = min + 15;
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/*
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* we need to wait 300us after changing comparator offset
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* to get stable temperature.
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* see "Usage Notes" on datasheet
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*/
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rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp);
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udelay(300);
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/* calculate current temperature */
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val = rcar_thermal_read(priv, THSSR) & CTEMP;
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val = (val * 5) - 65;
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dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n",
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priv->comp, min, max, val);
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/*
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* If val is same as min/max, then,
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* it should try again on next comparator.
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* But the val might be correct temperature.
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* Keep it on "tmp" and compare with next val.
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*/
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if (tmp == val)
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break;
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if (val <= min) {
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tmp = min;
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priv->comp--; /* try again */
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} else if (val >= max) {
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tmp = max;
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priv->comp++; /* try again */
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} else {
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tmp = val;
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break;
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}
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}
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*temp = tmp;
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return 0;
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}
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static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
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.get_temp = rcar_thermal_get_temp,
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};
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/*
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* platform functions
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*/
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static int rcar_thermal_probe(struct platform_device *pdev)
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{
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struct thermal_zone_device *zone;
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struct rcar_thermal_priv *priv;
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struct resource *res;
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int ret;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "Could not get platform resource\n");
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return -ENODEV;
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}
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv) {
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dev_err(&pdev->dev, "Could not allocate priv\n");
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return -ENOMEM;
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}
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priv->comp = 4; /* basic setup */
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priv->dev = &pdev->dev;
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spin_lock_init(&priv->lock);
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priv->base = devm_ioremap_nocache(&pdev->dev,
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res->start, resource_size(res));
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if (!priv->base) {
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dev_err(&pdev->dev, "Unable to ioremap thermal register\n");
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ret = -ENOMEM;
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goto error_free_priv;
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}
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zone = thermal_zone_device_register("rcar_thermal", 0, priv,
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&rcar_thermal_zone_ops, 0, 0);
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if (IS_ERR(zone)) {
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dev_err(&pdev->dev, "thermal zone device is NULL\n");
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ret = PTR_ERR(zone);
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goto error_iounmap;
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}
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platform_set_drvdata(pdev, zone);
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dev_info(&pdev->dev, "proved\n");
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return 0;
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error_iounmap:
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devm_iounmap(&pdev->dev, priv->base);
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error_free_priv:
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devm_kfree(&pdev->dev, priv);
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return ret;
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}
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static int rcar_thermal_remove(struct platform_device *pdev)
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{
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struct thermal_zone_device *zone = platform_get_drvdata(pdev);
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struct rcar_thermal_priv *priv = zone->devdata;
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thermal_zone_device_unregister(zone);
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platform_set_drvdata(pdev, NULL);
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devm_iounmap(&pdev->dev, priv->base);
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devm_kfree(&pdev->dev, priv);
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return 0;
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}
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static struct platform_driver rcar_thermal_driver = {
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.driver = {
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.name = "rcar_thermal",
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},
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.probe = rcar_thermal_probe,
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.remove = rcar_thermal_remove,
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};
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module_platform_driver(rcar_thermal_driver);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
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MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
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