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>

drivers/input/touchscreen/ad7879.c

@@ -595,7 +595,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
 	} else {
 		input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
-		touchscreen_parse_properties(input_dev, false);
+		touchscreen_parse_properties(input_dev, false, NULL);
 		if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
 			dev_err(dev, "Touchscreen pressure is not specified\n");
 			return ERR_PTR(-EINVAL);

drivers/input/touchscreen/cyttsp_core.c

@@ -657,7 +657,7 @@ struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
 
 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
-	touchscreen_parse_properties(input_dev, true);
+	touchscreen_parse_properties(input_dev, true, NULL);
 
 	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
 	if (error) {

drivers/input/touchscreen/edt-ft5x06.c

@@ -972,7 +972,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
 	input_set_abs_params(input, ABS_MT_POSITION_Y,
 			     0, tsdata->num_y * 64 - 1, 0, 0);
 
-	touchscreen_parse_properties(input, true);
+	touchscreen_parse_properties(input, true, NULL);
 
 	error = input_mt_init_slots(input, tsdata->max_support_points,
 				INPUT_MT_DIRECT);

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);

drivers/input/touchscreen/pixcir_i2c_ts.c

@@ -515,7 +515,7 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
 	} else {
 		input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
 		input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
-		touchscreen_parse_properties(input, true);
+		touchscreen_parse_properties(input, true, NULL);
 		if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
 		    !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
 			dev_err(dev, "Touchscreen size is not specified\n");

drivers/input/touchscreen/tsc200x-core.c

@@ -559,7 +559,7 @@ int tsc200x_probe(struct device *dev, int irq, __u16 bustype,
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
 
 	if (np)
-		touchscreen_parse_properties(input_dev, false);
+		touchscreen_parse_properties(input_dev, false, NULL);
 
 	input_dev->open = tsc200x_open;
 	input_dev->close = tsc200x_close;

include/linux/input/touchscreen.h

@@ -10,7 +10,26 @@
 #define _TOUCHSCREEN_H
 
 struct input_dev;
+struct input_mt_pos;
 
-void touchscreen_parse_properties(struct input_dev *dev, bool multitouch);
+struct touchscreen_properties {
+	unsigned int max_x;
+	unsigned int max_y;
+	bool invert_x;
+	bool invert_y;
+	bool swap_x_y;
+};
+
+void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
+				  struct touchscreen_properties *prop);
+
+void touchscreen_set_mt_pos(struct input_mt_pos *pos,
+			    const struct touchscreen_properties *prop,
+			    unsigned int x, unsigned int y);
+
+void touchscreen_report_pos(struct input_dev *input,
+			    const struct touchscreen_properties *prop,
+			    unsigned int x, unsigned int y,
+			    bool multitouch);
 
 #endif