1 files changed, 48 insertions, 6 deletions

diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index 56dc35c94bb1..bc642f1be376 100644
--- a/drivers/input/touchscreen/wacom_w8001.c
+++ b/drivers/input/touchscreen/wacom_w8001.c
@@ -62,6 +62,7 @@ struct w8001 {
         unsigned char response[W8001_MAX_LENGTH];
         unsigned char data[W8001_MAX_LENGTH];
         char phys[32];
+        int type;
 };
 
 static void parse_data(u8 *data, struct w8001_coord *coord)
@@ -88,11 +89,52 @@ static void parse_data(u8 *data, struct w8001_coord *coord)
         coord->tilt_y = data[8] & 0x7F;
 }
 
+static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
+{
+        struct input_dev *dev = w8001->dev;
+
+        /*
+         * We have 1 bit for proximity (rdy) and 3 bits for tip, side,
+         * side2/eraser. If rdy && f2 are set, this can be either pen + side2,
+         * or eraser. assume
+         * - if dev is already in proximity and f2 is toggled → pen + side2
+         * - if dev comes into proximity with f2 set → eraser
+         * If f2 disappears after assuming eraser, fake proximity out for
+         * eraser and in for pen.
+         */
+
+        if (!w8001->type) {
+                w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
+        } else if (w8001->type == BTN_TOOL_RUBBER) {
+                if (!coord->f2) {
+                        input_report_abs(dev, ABS_PRESSURE, 0);
+                        input_report_key(dev, BTN_TOUCH, 0);
+                        input_report_key(dev, BTN_STYLUS, 0);
+                        input_report_key(dev, BTN_STYLUS2, 0);
+                        input_report_key(dev, BTN_TOOL_RUBBER, 0);
+                        input_sync(dev);
+                        w8001->type = BTN_TOOL_PEN;
+                }
+        } else {
+                input_report_key(dev, BTN_STYLUS2, coord->f2);
+        }
+
+        input_report_abs(dev, ABS_X, coord->x);
+        input_report_abs(dev, ABS_Y, coord->y);
+        input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
+        input_report_key(dev, BTN_TOUCH, coord->tsw);
+        input_report_key(dev, BTN_STYLUS, coord->f1);
+        input_report_key(dev, w8001->type, coord->rdy);
+        input_sync(dev);
+
+        if (!coord->rdy)
+                w8001->type = 0;
+}
+
 static irqreturn_t w8001_interrupt(struct serio *serio,
                                    unsigned char data, unsigned int flags)
 {
         struct w8001 *w8001 = serio_get_drvdata(serio);
-        struct input_dev *dev = w8001->dev;
         struct w8001_coord coord;
         unsigned char tmp;
 
@@ -112,11 +154,7 @@ static irqreturn_t w8001_interrupt(struct serio *serio,
 
                 w8001->idx = 0;
                 parse_data(w8001->data, &coord);
-                input_report_abs(dev, ABS_X, coord.x);
-                input_report_abs(dev, ABS_Y, coord.y);
-                input_report_abs(dev, ABS_PRESSURE, coord.pen_pressure);
-                input_report_key(dev, BTN_TOUCH, coord.tsw);
-                input_sync(dev);
+                report_pen_events(w8001, &coord);
                 break;
 
         case 10:
@@ -221,6 +259,10 @@ static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 
         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+        input_dev->keybit[BIT_WORD(BTN_TOOL_PEN)] |= BIT_MASK(BTN_TOOL_PEN);
+        input_dev->keybit[BIT_WORD(BTN_TOOL_RUBBER)] |= BIT_MASK(BTN_TOOL_RUBBER);
+        input_dev->keybit[BIT_WORD(BTN_STYLUS)] |= BIT_MASK(BTN_STYLUS);
+        input_dev->keybit[BIT_WORD(BTN_STYLUS2)] |= BIT_MASK(BTN_STYLUS2);
 
         serio_set_drvdata(serio, w8001);
         err = serio_open(serio, drv);