Input: of_touchscreen - add support for inverted / swapped axes

Extend touchscreen_parse_properties() with support for the
touchscreen-inverted-x/y and touchscreen-swapped-x-y properties and
add touchscreen_set_mt_pos() and touchscreen_report_pos() helper
functions for storing coordinates into a input_mt_pos struct, or
directly reporting them, taking these properties into account.

This commit also modifies the existing callers of
touchscreen_parse_properties() to pass in NULL for the new third
argument, keeping the existing behavior.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 80 insertions, 1 deletions

diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
index bb6f2fe14667..8d7f9c8f2771 100644
--- a/drivers/input/touchscreen/of_touchscreen.c
+++ b/drivers/input/touchscreen/of_touchscreen.c
@@ -55,12 +55,16 @@ static void touchscreen_set_params(struct input_dev *dev,
  * @input: input device that should be parsed
  * @multitouch: specifies whether parsed properties should be applied to
  *	single-touch or multi-touch axes
+ * @prop: pointer to a struct touchscreen_properties into which to store
+ *	axis swap and invert info for use with touchscreen_report_x_y();
+ *	or %NULL
  *
  * This function parses common DT properties for touchscreens and setups the
  * input device accordingly. The function keeps previously set up default
  * values if no value is specified via DT.
  */
-void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
+void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
+				  struct touchscreen_properties *prop)
 {
 	struct device *dev = input->dev.parent;
 	unsigned int axis;
@@ -104,5 +108,80 @@ void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
 						&fuzz);
 	if (data_present)
 		touchscreen_set_params(input, axis, maximum, fuzz);
+
+	if (!prop)
+		return;
+
+	axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
+
+	prop->max_x = input_abs_get_max(input, axis);
+	prop->max_y = input_abs_get_max(input, axis + 1);
+	prop->invert_x =
+		device_property_read_bool(dev, "touchscreen-inverted-x");
+	prop->invert_y =
+		device_property_read_bool(dev, "touchscreen-inverted-y");
+	prop->swap_x_y =
+		device_property_read_bool(dev, "touchscreen-swapped-x-y");
+
+	if (prop->swap_x_y)
+		swap(input->absinfo[axis], input->absinfo[axis + 1]);
 }
 EXPORT_SYMBOL(touchscreen_parse_properties);
+
+static void
+touchscreen_apply_prop_to_x_y(const struct touchscreen_properties *prop,
+			      unsigned int *x, unsigned int *y)
+{
+	if (prop->invert_x)
+		*x = prop->max_x - *x;
+
+	if (prop->invert_y)
+		*y = prop->max_y - *y;
+
+	if (prop->swap_x_y)
+		swap(*x, *y);
+}
+
+/**
+ * touchscreen_set_mt_pos - Set input_mt_pos coordinates
+ * @pos: input_mt_pos to set coordinates of
+ * @prop: pointer to a struct touchscreen_properties
+ * @x: X coordinate to store in pos
+ * @y: Y coordinate to store in pos
+ *
+ * Adjust the passed in x and y values applying any axis inversion and
+ * swapping requested in the passed in touchscreen_properties and store
+ * the result in a struct input_mt_pos.
+ */
+void touchscreen_set_mt_pos(struct input_mt_pos *pos,
+			    const struct touchscreen_properties *prop,
+			    unsigned int x, unsigned int y)
+{
+	touchscreen_apply_prop_to_x_y(prop, &x, &y);
+	pos->x = x;
+	pos->y = y;
+}
+EXPORT_SYMBOL(touchscreen_set_mt_pos);
+
+/**
+ * touchscreen_report_pos - Report touchscreen coordinates
+ * @input: input_device to report coordinates for
+ * @prop: pointer to a struct touchscreen_properties
+ * @x: X coordinate to report
+ * @y: Y coordinate to report
+ * @multitouch: Report coordinates on single-touch or multi-touch axes
+ *
+ * Adjust the passed in x and y values applying any axis inversion and
+ * swapping requested in the passed in touchscreen_properties and then
+ * report the resulting coordinates on the input_dev's x and y axis.
+ */
+void touchscreen_report_pos(struct input_dev *input,
+			    const struct touchscreen_properties *prop,
+			    unsigned int x, unsigned int y,
+			    bool multitouch)
+{
+	touchscreen_apply_prop_to_x_y(prop, &x, &y);
+	input_report_abs(input, multitouch ? ABS_MT_POSITION_X : ABS_X, x);
+	input_report_abs(input, multitouch ? ABS_MT_POSITION_Y : ABS_Y, y);
+}
+EXPORT_SYMBOL(touchscreen_report_pos);