thermal: add Renesas R-Car thermal sensor support

This patch add basic Renesas R-Car thermal sensor support.
It was tested on R-Car H1 Marzen board.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

3 files changed, 270 insertions, 1 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3ab2bd540b54..7dd8c34552e1 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -27,3 +27,11 @@ config SPEAR_THERMAL
         help
           Enable this to plug the SPEAr thermal sensor driver into the Linux
           thermal framework
+
+config RCAR_THERMAL
+        tristate "Renesas R-Car thermal driver"
+        depends on THERMAL
+        depends on ARCH_SHMOBILE
+        help
+          Enable this to plug the R-Car thermal sensor driver into the Linux
+          thermal framework
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index a9fff0bf4b14..fd9369aeb96f 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -3,4 +3,5 @@
 #
 
 obj-$(CONFIG_THERMAL)           += thermal_sys.o
-obj-$(CONFIG_SPEAR_THERMAL)             += spear_thermal.o
\ No newline at end of file
+obj-$(CONFIG_SPEAR_THERMAL)             += spear_thermal.o
+obj-$(CONFIG_RCAR_THERMAL)      += rcar_thermal.o
diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
new file mode 100644
index 000000000000..d4452716aaab
--- /dev/null
+++ b/drivers/thermal/rcar_thermal.c
@@ -0,0 +1,260 @@
+/*
+ *  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;
+};
+
+/*
+ *              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 = zone->devdata;
+        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 = 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;
+        int ret;
+
+        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");
+                ret = -ENOMEM;
+                goto error_free_priv;
+        }
+
+        zone = thermal_zone_device_register("rcar_thermal", 0, priv,
+                                            &rcar_thermal_zone_ops, 0, 0);
+        if (IS_ERR(zone)) {
+                dev_err(&pdev->dev, "thermal zone device is NULL\n");
+                ret = PTR_ERR(zone);
+                goto error_iounmap;
+        }
+
+        platform_set_drvdata(pdev, zone);
+
+        dev_info(&pdev->dev, "proved\n");
+
+        return 0;
+
+error_iounmap:
+        devm_iounmap(&pdev->dev, priv->base);
+error_free_priv:
+        devm_kfree(&pdev->dev, priv);
+
+        return ret;
+}
+
+static int rcar_thermal_remove(struct platform_device *pdev)
+{
+        struct thermal_zone_device *zone = platform_get_drvdata(pdev);
+        struct rcar_thermal_priv *priv = zone->devdata;
+
+        thermal_zone_device_unregister(zone);
+        platform_set_drvdata(pdev, NULL);
+
+        devm_iounmap(&pdev->dev, priv->base);
+        devm_kfree(&pdev->dev, priv);
+
+        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>");