[PATCH 4/4] Input: ads7846 - add support for general touchscreen bindings

[Marco Felsch <m.felsch@pengutronix.de>]

A few vendor specific bindings are now covered by common bindings.

Let the driver parse the common bindings to make use of common
inverting and swapping mechnism. Aslo make use of
touchscreen_report_pos() to ensure the correct inverting-swapping
order.

The vendor specific properties are used as default (backward
compatibility) and gets overwritten by common bindings.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/input/touchscreen/ads7846.c | 38 +++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 5a7a8425d619..2fe3b91f1db8 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -23,6 +23,7 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/input.h>
+#include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/pm.h>
@@ -132,6 +133,8 @@ struct ads7846 {
 
 	u16			penirq_recheck_delay_usecs;
 
+	struct touchscreen_properties core_prop;
+
 	struct mutex		lock;
 	bool			stopped;	/* P: lock */
 	bool			disabled;	/* P: lock */
@@ -826,17 +829,13 @@ static void ads7846_report_state(struct ads7846 *ts)
 	if (Rt) {
 		struct input_dev *input = ts->input;
 
-		if (ts->swap_xy)
-			swap(x, y);
-
 		if (!ts->pendown) {
 			input_report_key(input, BTN_TOUCH, 1);
 			ts->pendown = true;
 			dev_vdbg(&ts->spi->dev, "DOWN\n");
 		}
 
-		input_report_abs(input, ABS_X, x);
-		input_report_abs(input, ABS_Y, y);
+		touchscreen_report_pos(input, &ts->core_prop, x, y, false);
 		input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 
 		input_sync(input);
@@ -1188,6 +1187,7 @@ static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
 	struct ads7846_platform_data *pdata;
 	struct device_node *node = dev->of_node;
 	const struct of_device_id *match;
+	u32 value;
 
 	if (!node) {
 		dev_err(dev, "Device does not have associated DT data\n");
@@ -1226,10 +1226,18 @@ static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
 	of_property_read_u16(node, "ti,x-max", &pdata->x_max);
 	of_property_read_u16(node, "ti,y-max", &pdata->y_max);
 
+	/*
+	 * touchscreen-max-pressure gets parsed during
+	 * touchscreen_parse_properties()
+	 */
 	of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
+	if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
+		pdata->pressure_min = (u16) value;
 	of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
 
 	of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
+	if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
+		pdata->debounce_max = (u16) value;
 	of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
 	of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
 
@@ -1314,10 +1322,7 @@ static int ads7846_probe(struct spi_device *spi)
 	ts->model = pdata->model ? : 7846;
 	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
-	ts->pressure_max = pdata->pressure_max ? : ~0;
-
 	ts->vref_mv = pdata->vref_mv;
-	ts->swap_xy = pdata->swap_xy;
 
 	if (pdata->filter != NULL) {
 		if (pdata->filter_init != NULL) {
@@ -1368,6 +1373,23 @@ static int ads7846_probe(struct spi_device *spi)
 	input_set_abs_params(input_dev, ABS_PRESSURE,
 			pdata->pressure_min, pdata->pressure_max, 0, 0);
 
+	/*
+	 * Parse common framework properties. Must be done here to ensure the
+	 * correct behaviour in case of using the legacy vendor bindings. The
+	 * general binding value overrides the vendor specific one.
+	 */
+	touchscreen_parse_properties(ts->input, false, &ts->core_prop);
+	ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
+
+	/*
+	 * Check if legacy ti,swap-xy binding is used instead of
+	 * touchscreen-swapped-x-y
+	 */
+	if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
+		swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
+		ts->core_prop.swap_x_y = true;
+	}
+
 	ads7846_setup_spi_msg(ts, pdata);
 
 	ts->reg = regulator_get(&spi->dev, "vcc");
-- 
2.20.1