1 files changed, 58 insertions, 12 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index c3139bc2aa0d..e5a668ce884d 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -47,6 +47,17 @@ static DEFINE_MUTEX(input_mutex);
 
 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
 
+static const unsigned int input_max_code[EV_CNT] = {
+	[EV_KEY] = KEY_MAX,
+	[EV_REL] = REL_MAX,
+	[EV_ABS] = ABS_MAX,
+	[EV_MSC] = MSC_MAX,
+	[EV_SW] = SW_MAX,
+	[EV_LED] = LED_MAX,
+	[EV_SND] = SND_MAX,
+	[EV_FF] = FF_MAX,
+};
+
 static inline int is_event_supported(unsigned int code,
 				     unsigned long *bm, unsigned int max)
 {
@@ -511,6 +522,9 @@ void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 {
 	struct input_absinfo *absinfo;
 
+	__set_bit(EV_ABS, dev->evbit);
+	__set_bit(axis, dev->absbit);
+
 	input_alloc_absinfo(dev);
 	if (!dev->absinfo)
 		return;
@@ -520,12 +534,45 @@ void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 	absinfo->maximum = max;
 	absinfo->fuzz = fuzz;
 	absinfo->flat = flat;
-
-	__set_bit(EV_ABS, dev->evbit);
-	__set_bit(axis, dev->absbit);
 }
 EXPORT_SYMBOL(input_set_abs_params);
 
+/**
+ * input_copy_abs - Copy absinfo from one input_dev to another
+ * @dst: Destination input device to copy the abs settings to
+ * @dst_axis: ABS_* value selecting the destination axis
+ * @src: Source input device to copy the abs settings from
+ * @src_axis: ABS_* value selecting the source axis
+ *
+ * Set absinfo for the selected destination axis by copying it from
+ * the specified source input device's source axis.
+ * This is useful to e.g. setup a pen/stylus input-device for combined
+ * touchscreen/pen hardware where the pen uses the same coordinates as
+ * the touchscreen.
+ */
+void input_copy_abs(struct input_dev *dst, unsigned int dst_axis,
+		    const struct input_dev *src, unsigned int src_axis)
+{
+	/* src must have EV_ABS and src_axis set */
+	if (WARN_ON(!(test_bit(EV_ABS, src->evbit) &&
+		      test_bit(src_axis, src->absbit))))
+		return;
+
+	/*
+	 * input_alloc_absinfo() may have failed for the source. Our caller is
+	 * expected to catch this when registering the input devices, which may
+	 * happen after the input_copy_abs() call.
+	 */
+	if (!src->absinfo)
+		return;
+
+	input_set_capability(dst, EV_ABS, dst_axis);
+	if (!dst->absinfo)
+		return;
+
+	dst->absinfo[dst_axis] = src->absinfo[src_axis];
+}
+EXPORT_SYMBOL(input_copy_abs);
 
 /**
  * input_grab_device - grabs device for exclusive use
@@ -2074,6 +2121,14 @@ EXPORT_SYMBOL(input_get_timestamp);
  */
 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
 {
+	if (type < EV_CNT && input_max_code[type] &&
+	    code > input_max_code[type]) {
+		pr_err("%s: invalid code %u for type %u\n", __func__, code,
+		       type);
+		dump_stack();
+		return;
+	}
+
 	switch (type) {
 	case EV_KEY:
 		__set_bit(code, dev->keybit);
@@ -2085,9 +2140,6 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
 
 	case EV_ABS:
 		input_alloc_absinfo(dev);
-		if (!dev->absinfo)
-			return;
-
 		__set_bit(code, dev->absbit);
 		break;
 
@@ -2285,12 +2337,6 @@ int input_register_device(struct input_dev *dev)
 	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
 	__clear_bit(KEY_RESERVED, dev->keybit);
 
-	/* Buttonpads should not map BTN_RIGHT and/or BTN_MIDDLE. */
-	if (test_bit(INPUT_PROP_BUTTONPAD, dev->propbit)) {
-		__clear_bit(BTN_RIGHT, dev->keybit);
-		__clear_bit(BTN_MIDDLE, dev->keybit);
-	}
-
 	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
 	input_cleanse_bitmasks(dev);