1 files changed, 52 insertions, 10 deletions

diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
index f8f9b84230b1..b82b5207c78b 100644
--- a/drivers/input/touchscreen/of_touchscreen.c
+++ b/drivers/input/touchscreen/of_touchscreen.c
@@ -11,8 +11,41 @@
 
 #include <linux/of.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 
+static u32 of_get_optional_u32(struct device_node *np,
+                               const char *property)
+{
+        u32 val = 0;
+
+        of_property_read_u32(np, property, &val);
+
+        return val;
+}
+
+static void touchscreen_set_params(struct input_dev *dev,
+                                   unsigned long axis,
+                                   int max, int fuzz)
+{
+        struct input_absinfo *absinfo;
+
+        if (!test_bit(axis, dev->absbit)) {
+                /*
+                 * Emit a warning only if the axis is not a multitouch
+                 * axis, which might not be set by the driver.
+                 */
+                if (!input_is_mt_axis(axis))
+                        dev_warn(&dev->dev,
+                                 "DT specifies parameters but the axis is not set up\n");
+                return;
+        }
+
+        absinfo = &dev->absinfo[axis];
+        absinfo->maximum = max;
+        absinfo->fuzz = fuzz;
+}
+
 /**
  * touchscreen_parse_of_params - parse common touchscreen DT properties
  * @dev: device that should be parsed
@@ -24,22 +57,31 @@
 void touchscreen_parse_of_params(struct input_dev *dev)
 {
         struct device_node *np = dev->dev.parent->of_node;
-        struct input_absinfo *absinfo;
+        u32 maximum, fuzz;
 
         input_alloc_absinfo(dev);
         if (!dev->absinfo)
                 return;
 
-        absinfo = &dev->absinfo[ABS_X];
-        of_property_read_u32(np, "touchscreen-size-x", &absinfo->maximum);
-        of_property_read_u32(np, "touchscreen-fuzz-x", &absinfo->fuzz);
+        maximum = of_get_optional_u32(np, "touchscreen-size-x");
+        fuzz = of_get_optional_u32(np, "touchscreen-fuzz-x");
+        if (maximum || fuzz) {
+                touchscreen_set_params(dev, ABS_X, maximum, fuzz);
+                touchscreen_set_params(dev, ABS_MT_POSITION_X, maximum, fuzz);
+        }
 
-        absinfo = &dev->absinfo[ABS_Y];
-        of_property_read_u32(np, "touchscreen-size-y", &absinfo->maximum);
-        of_property_read_u32(np, "touchscreen-fuzz-y", &absinfo->fuzz);
+        maximum = of_get_optional_u32(np, "touchscreen-size-y");
+        fuzz = of_get_optional_u32(np, "touchscreen-fuzz-y");
+        if (maximum || fuzz) {
+                touchscreen_set_params(dev, ABS_Y, maximum, fuzz);
+                touchscreen_set_params(dev, ABS_MT_POSITION_Y, maximum, fuzz);
+        }
 
-        absinfo = &dev->absinfo[ABS_PRESSURE];
-        of_property_read_u32(np, "touchscreen-max-pressure", &absinfo->maximum);
-        of_property_read_u32(np, "touchscreen-fuzz-pressure", &absinfo->fuzz);
+        maximum = of_get_optional_u32(np, "touchscreen-max-pressure");
+        fuzz = of_get_optional_u32(np, "touchscreen-fuzz-pressure");
+        if (maximum || fuzz) {
+                touchscreen_set_params(dev, ABS_PRESSURE, maximum, fuzz);
+                touchscreen_set_params(dev, ABS_MT_PRESSURE, maximum, fuzz);
+        }
 }
 EXPORT_SYMBOL(touchscreen_parse_of_params);