Input: goodix - add axis swapping and axis inversion support

Implement support for the following device-tree and ACPI 5.1 DSD
properties in the goodix touchscreen driver:

 - touchscreen-inverted-x:  X axis is inverted (boolean)
 - touchscreen-inverted-y:  Y axis is inverted (boolean)
 - touchscreen-swapped-x-y: X and Y axis are swapped (boolean)

These are necessary on tablets which have a display in portrait
format while the touchscreen is in landscape format, such as e.g.
the MSI Primo 81.

Signed-off-by: Karsten Merker <merker@debian.org>
Tested-by: Bastien Nocera <hadess@hadess.net>
Tested-by: Irina Tirdea <irina.tirdea@intel.com> (with ACPI DSD properties)
Tested-by: Aleksei Mamlin <mamlinav@gmail.com> (with device-tree properties)
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 0acefe49540d..b5e910a44cdf 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -2,6 +2,7 @@
  *  Driver for Goodix Touchscreens
  *
  *  Copyright (c) 2014 Red Hat Inc.
+ *  Copyright (c) 2015 K. Merker <merker@debian.org>
  *
  *  This code is based on gt9xx.c authored by andrew@goodix.com:
  *
@@ -35,6 +36,9 @@ struct goodix_ts_data {
         struct input_dev *input_dev;
         int abs_x_max;
         int abs_y_max;
+        bool swapped_x_y;
+        bool inverted_x;
+        bool inverted_y;
         unsigned int max_touch_num;
         unsigned int int_trigger_type;
         bool rotated_screen;
@@ -235,6 +239,14 @@ static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
                 input_y = ts->abs_y_max - input_y;
         }
 
+        /* Inversions have to happen before axis swapping */
+        if (ts->inverted_x)
+                input_x = ts->abs_x_max - input_x;
+        if (ts->inverted_y)
+                input_y = ts->abs_y_max - input_y;
+        if (ts->swapped_x_y)
+                swap(input_x, input_y);
+
         input_mt_slot(ts->input_dev, id);
         input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
         input_report_abs(ts->input_dev, ABS_MT_POSITION_X, input_x);
@@ -486,6 +498,8 @@ static void goodix_read_config(struct goodix_ts_data *ts)
                          error);
                 ts->abs_x_max = GOODIX_MAX_WIDTH;
                 ts->abs_y_max = GOODIX_MAX_HEIGHT;
+                if (ts->swapped_x_y)
+                        swap(ts->abs_x_max, ts->abs_y_max);
                 ts->int_trigger_type = GOODIX_INT_TRIGGER;
                 ts->max_touch_num = GOODIX_MAX_CONTACTS;
                 return;
@@ -493,6 +507,8 @@ static void goodix_read_config(struct goodix_ts_data *ts)
 
         ts->abs_x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
         ts->abs_y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
+        if (ts->swapped_x_y)
+                swap(ts->abs_x_max, ts->abs_y_max);
         ts->int_trigger_type = config[TRIGGER_LOC] & 0x03;
         ts->max_touch_num = config[MAX_CONTACTS_LOC] & 0x0f;
         if (!ts->abs_x_max || !ts->abs_y_max || !ts->max_touch_num) {
@@ -500,6 +516,8 @@ static void goodix_read_config(struct goodix_ts_data *ts)
                         "Invalid config, using defaults\n");
                 ts->abs_x_max = GOODIX_MAX_WIDTH;
                 ts->abs_y_max = GOODIX_MAX_HEIGHT;
+                if (ts->swapped_x_y)
+                        swap(ts->abs_x_max, ts->abs_y_max);
                 ts->max_touch_num = GOODIX_MAX_CONTACTS;
         }
 
@@ -622,6 +640,13 @@ static int goodix_configure_dev(struct goodix_ts_data *ts)
 {
         int error;
 
+        ts->swapped_x_y = device_property_read_bool(&ts->client->dev,
+                                                    "touchscreen-swapped-x-y");
+        ts->inverted_x = device_property_read_bool(&ts->client->dev,
+                                                   "touchscreen-inverted-x");
+        ts->inverted_y = device_property_read_bool(&ts->client->dev,
+                                                   "touchscreen-inverted-y");
+
         goodix_read_config(ts);
 
         error = goodix_request_input_dev(ts);