Input: Break out MT data

Move all MT-related things to a separate place. This saves some
bytes for non-mt input devices, and prepares for new MT features.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

5 files changed, 61 insertions, 46 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 6c58bfff01a3..a0692c551be5 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -653,20 +653,22 @@ static int evdev_handle_mt_request(struct input_dev *dev,
 				   unsigned int size,
 				   int __user *ip)
 {
-	const struct input_mt_slot *mt = dev->mt;
+	const struct input_mt *mt = dev->mt;
 	unsigned int code;
 	int max_slots;
 	int i;
 
 	if (get_user(code, &ip[0]))
 		return -EFAULT;
-	if (!input_is_mt_value(code))
+	if (!mt || !input_is_mt_value(code))
 		return -EINVAL;
 
 	max_slots = (size - sizeof(__u32)) / sizeof(__s32);
-	for (i = 0; i < dev->mtsize && i < max_slots; i++)
-		if (put_user(input_mt_get_value(&mt[i], code), &ip[1 + i]))
+	for (i = 0; i < mt->num_slots && i < max_slots; i++) {
+		int value = input_mt_get_value(&mt->slots[i], code);
+		if (put_user(value, &ip[1 + i]))
 			return -EFAULT;
+	}
 
 	return 0;
 }
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 70a16c7da8cc..37ee1f925d23 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -27,26 +27,28 @@
  */
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
 {
+	struct input_mt *mt = dev->mt;
 	int i;
 
 	if (!num_slots)
 		return 0;
-	if (dev->mt)
-		return dev->mtsize != num_slots ? -EINVAL : 0;
+	if (mt)
+		return mt->num_slots != num_slots ? -EINVAL : 0;
 
-	dev->mt = kcalloc(num_slots, sizeof(struct input_mt_slot), GFP_KERNEL);
-	if (!dev->mt)
+	mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL);
+	if (!mt)
 		return -ENOMEM;
 
-	dev->mtsize = num_slots;
+	mt->num_slots = num_slots;
 	input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
 	input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
 	input_set_events_per_packet(dev, 6 * num_slots);
 
 	/* Mark slots as 'unused' */
 	for (i = 0; i < num_slots; i++)
-		input_mt_set_value(&dev->mt[i], ABS_MT_TRACKING_ID, -1);
+		input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
 
+	dev->mt = mt;
 	return 0;
 }
 EXPORT_SYMBOL(input_mt_init_slots);
@@ -62,9 +64,6 @@ void input_mt_destroy_slots(struct input_dev *dev)
 {
 	kfree(dev->mt);
 	dev->mt = NULL;
-	dev->mtsize = 0;
-	dev->slot = 0;
-	dev->trkid = 0;
 }
 EXPORT_SYMBOL(input_mt_destroy_slots);
 
@@ -83,18 +82,19 @@ EXPORT_SYMBOL(input_mt_destroy_slots);
 void input_mt_report_slot_state(struct input_dev *dev,
 				unsigned int tool_type, bool active)
 {
-	struct input_mt_slot *mt;
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *slot;
 	int id;
 
-	if (!dev->mt || !active) {
+	if (!mt || !active) {
 		input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
 		return;
 	}
 
-	mt = &dev->mt[dev->slot];
-	id = input_mt_get_value(mt, ABS_MT_TRACKING_ID);
-	if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type)
-		id = input_mt_new_trkid(dev);
+	slot = &mt->slots[mt->slot];
+	id = input_mt_get_value(slot, ABS_MT_TRACKING_ID);
+	if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type)
+		id = input_mt_new_trkid(mt);
 
 	input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
 	input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
@@ -135,13 +135,19 @@ EXPORT_SYMBOL(input_mt_report_finger_count);
  */
 void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
 {
-	struct input_mt_slot *oldest = NULL;
-	int oldid = dev->trkid;
-	int count = 0;
-	int i;
+	struct input_mt *mt = dev->mt;
+	struct input_mt_slot *oldest;
+	int oldid, count, i;
+
+	if (!mt)
+		return;
+
+	oldest = 0;
+	oldid = mt->trkid;
+	count = 0;
 
-	for (i = 0; i < dev->mtsize; ++i) {
-		struct input_mt_slot *ps = &dev->mt[i];
+	for (i = 0; i < mt->num_slots; ++i) {
+		struct input_mt_slot *ps = &mt->slots[i];
 		int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
 
 		if (id < 0)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 8921c6180c51..79a4a2ad74de 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -166,6 +166,7 @@ static void input_stop_autorepeat(struct input_dev *dev)
 static int input_handle_abs_event(struct input_dev *dev,
 				  unsigned int code, int *pval)
 {
+	struct input_mt *mt = dev->mt;
 	bool is_mt_event;
 	int *pold;
 
@@ -174,8 +175,8 @@ static int input_handle_abs_event(struct input_dev *dev,
 		 * "Stage" the event; we'll flush it later, when we
 		 * get actual touch data.
 		 */
-		if (*pval >= 0 && *pval < dev->mtsize)
-			dev->slot = *pval;
+		if (mt && *pval >= 0 && *pval < mt->num_slots)
+			mt->slot = *pval;
 
 		return INPUT_IGNORE_EVENT;
 	}
@@ -184,9 +185,8 @@ static int input_handle_abs_event(struct input_dev *dev,
 
 	if (!is_mt_event) {
 		pold = &dev->absinfo[code].value;
-	} else if (dev->mt) {
-		struct input_mt_slot *mtslot = &dev->mt[dev->slot];
-		pold = &mtslot->abs[code - ABS_MT_FIRST];
+	} else if (mt) {
+		pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 	} else {
 		/*
 		 * Bypass filtering for multi-touch events when
@@ -205,9 +205,9 @@ static int input_handle_abs_event(struct input_dev *dev,
 	}
 
 	/* Flush pending "slot" event */
-	if (is_mt_event && dev->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
-		input_abs_set_val(dev, ABS_MT_SLOT, dev->slot);
-		input_pass_event(dev, EV_ABS, ABS_MT_SLOT, dev->slot);
+	if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
+		input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
+		input_pass_event(dev, EV_ABS, ABS_MT_SLOT, mt->slot);
 	}
 
 	return INPUT_PASS_TO_HANDLERS;
@@ -1751,8 +1751,8 @@ static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
 	int i;
 	unsigned int events;
 
-	if (dev->mtsize) {
-		mt_slots = dev->mtsize;
+	if (dev->mt) {
+		mt_slots = dev->mt->num_slots;
 	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
 		mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
 			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
diff --git a/include/linux/input.h b/include/linux/input.h
index 725dcd0f63a4..9da4f5796fd6 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -1203,11 +1203,7 @@ struct ff_effect {
  *	software autorepeat
  * @timer: timer for software autorepeat
  * @rep: current values for autorepeat parameters (delay, rate)
- * @mt: pointer to array of struct input_mt_slot holding current values
- *	of tracked contacts
- * @mtsize: number of MT slots the device uses
- * @slot: MT slot currently being transmitted
- * @trkid: stores MT tracking ID for the current contact
+ * @mt: pointer to multitouch state
  * @absinfo: array of &struct input_absinfo elements holding information
  *	about absolute axes (current value, min, max, flat, fuzz,
  *	resolution)
@@ -1287,10 +1283,7 @@ struct input_dev {
 
 	int rep[REP_CNT];
 
-	struct input_mt_slot *mt;
-	int mtsize;
-	int slot;
-	int trkid;
+	struct input_mt *mt;
 
 	struct input_absinfo *absinfo;
 
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index f86737586e19..63458bced77d 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -23,6 +23,20 @@ struct input_mt_slot {
 	int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
 };
 
+/**
+ * struct input_mt - state of tracked contacts
+ * @trkid: stores MT tracking ID for the next contact
+ * @num_slots: number of MT slots the device uses
+ * @slot: MT slot currently being transmitted
+ * @slots: array of slots holding current values of tracked contacts
+ */
+struct input_mt {
+	int trkid;
+	int num_slots;
+	int slot;
+	struct input_mt_slot slots[];
+};
+
 static inline void input_mt_set_value(struct input_mt_slot *slot,
 				      unsigned code, int value)
 {
@@ -38,9 +52,9 @@ static inline int input_mt_get_value(const struct input_mt_slot *slot,
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots);
 void input_mt_destroy_slots(struct input_dev *dev);
 
-static inline int input_mt_new_trkid(struct input_dev *dev)
+static inline int input_mt_new_trkid(struct input_mt *mt)
 {
-	return dev->trkid++ & TRKID_MAX;
+	return mt->trkid++ & TRKID_MAX;
 }
 
 static inline void input_mt_slot(struct input_dev *dev, int slot)