1 files changed, 34 insertions, 12 deletions

diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
index b93a28b955fd..c0116994067d 100644
--- a/drivers/input/touchscreen/sun4i-ts.c
+++ b/drivers/input/touchscreen/sun4i-ts.c
@@ -30,6 +30,10 @@
  * These kinds of heuristics are just asking for trouble (and don't belong
  * in the kernel). So this driver offers straight forward, reliable single
  * touch functionality only.
+ *
+ * s.a. A20 User Manual "1.15 TP" (Documentation/arm/sunxi/README)
+ * (looks like the description in the A20 User Manual v1.3 is better
+ * than the one in the A10 User Manual v.1.5)
  */
 
 #include <linux/err.h>
@@ -193,7 +197,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)
         if (ts->temp_data == -1)
                 return -EAGAIN;
 
-        *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step;
+        *temp = ts->temp_data * ts->temp_step - ts->temp_offset;
 
         return 0;
 }
@@ -246,6 +250,8 @@ static int sun4i_ts_probe(struct platform_device *pdev)
         int error;
         u32 reg;
         bool ts_attached;
+        u32 tp_sensitive_adjust = 15;
+        u32 filter_type = 1;
 
         ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
         if (!ts)
@@ -255,22 +261,31 @@ static int sun4i_ts_probe(struct platform_device *pdev)
         ts->ignore_fifo_data = true;
         ts->temp_data = -1;
         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
-                /* Allwinner SDK has temperature = -271 + (value / 6) (C) */
-                ts->temp_offset = 1626;
+                /* Allwinner SDK has temperature (C) = (value / 6) - 271 */
+                ts->temp_offset = 271000;
                 ts->temp_step = 167;
+        } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
+                /*
+                 * The A10 temperature sensor has quite a wide spread, these
+                 * parameters are based on the averaging of the calibration
+                 * results of 4 completely different boards, with a spread of
+                 * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
+                 */
+                ts->temp_offset = 257000;
+                ts->temp_step = 133;
         } else {
                 /*
                  * The user manuals do not contain the formula for calculating
                  * the temperature. The formula used here is from the AXP209,
                  * which is designed by X-Powers, an affiliate of Allwinner:
                  *
-                 *     temperature = -144.7 + (value * 0.1)
+                 *     temperature (C) = (value * 0.1) - 144.7
                  *
                  * Allwinner does not have any documentation whatsoever for
                  * this hardware. Moreover, it is claimed that the sensor
                  * is inaccurate and cannot work properly.
                  */
-                ts->temp_offset = 1447;
+                ts->temp_offset = 144700;
                 ts->temp_step = 100;
         }
 
@@ -313,14 +328,20 @@ static int sun4i_ts_probe(struct platform_device *pdev)
                ts->base + TP_CTRL0);
 
         /*
-         * sensitive_adjust = 15 : max, which is not all that sensitive,
+         * tp_sensitive_adjust is an optional property
          * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
          */
-        writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0),
+        of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
+                             &tp_sensitive_adjust);
+        writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
                ts->base + TP_CTRL2);
 
-        /* Enable median filter, type 1 : 5/3 */
-        writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3);
+        /*
+         * Enable median and averaging filter, optional property for
+         * filter type.
+         */
+        of_property_read_u32(np, "allwinner,filter-type", &filter_type);
+        writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
 
         /* Enable temperature measurement, period 1953 (2 seconds) */
         writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
@@ -330,10 +351,10 @@ static int sun4i_ts_probe(struct platform_device *pdev)
          * finally enable tp mode.
          */
         reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
-        if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts"))
-                reg |= TP_MODE_EN(1);
-        else
+        if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
                 reg |= SUN6I_TP_MODE_EN(1);
+        else
+                reg |= TP_MODE_EN(1);
         writel(reg, ts->base + TP_CTRL1);
 
         /*
@@ -383,6 +404,7 @@ static int sun4i_ts_remove(struct platform_device *pdev)
 
 static const struct of_device_id sun4i_ts_of_match[] = {
         { .compatible = "allwinner,sun4i-a10-ts", },
+        { .compatible = "allwinner,sun5i-a13-ts", },
         { .compatible = "allwinner,sun6i-a31-ts", },
         { /* sentinel */ }
 };