thermal: rcar: enable CPCTL to use hardware TSC deciding

If CPCTL was 1 on R-Car thermal, the thermal comparator offset
is automatically decided by hardware.
And this CPCTL is the conditions which validate interrupt.
This patch enabled CPCTL.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 26 insertions, 65 deletions

diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
index 47b2b227c91e..068b2a1c5c15 100644
--- a/drivers/thermal/rcar_thermal.c
+++ b/drivers/thermal/rcar_thermal.c
@@ -33,7 +33,7 @@
 #define THSSR   0x30
 
 /* THSCR */
-#define CPTAP   0xf
+#define CPCTL   (1 << 12)
 
 /* THSSR */
 #define CTEMP   0x3f
@@ -43,11 +43,11 @@ 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)
+#define rcar_priv_to_dev(priv)          ((priv)->dev)
 
 /*
  *              basic functions
@@ -103,79 +103,41 @@ 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;
-
+        struct device *dev = rcar_priv_to_dev(priv);
+        int i;
+        int ctemp, old, new;
+
+        /*
+         * TSC decides a value of CPTAP automatically,
+         * and this is the conditions which validate interrupt.
+         */
+        rcar_thermal_bset(priv, THSCR, CPCTL, CPCTL);
+
+        ctemp = 0;
+        old = ~0;
+        for (i = 0; i < 128; i++) {
                 /*
                  * 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;
+                new = rcar_thermal_read(priv, THSSR) & CTEMP;
+                if (new == old) {
+                        ctemp = new;
                         break;
                 }
+                old = new;
         }
 
-        *temp = MCELSIUS(tmp);
+        if (!ctemp) {
+                dev_err(dev, "thermal sensor was broken\n");
+                return -EINVAL;
+        }
+
+        *temp = MCELSIUS((ctemp * 5) - 65);
+
         return 0;
 }
 
@@ -262,7 +224,6 @@ static int rcar_thermal_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
-        priv->comp = 4; /* basic setup */
         priv->dev = &pdev->dev;
         spin_lock_init(&priv->lock);
         priv->base = devm_ioremap_nocache(&pdev->dev,