Input: synaptics - simplify pass-through port handling

There was too much knowledge about internals if serio in the pass-through
handling, clean it up.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/mouse/synaptics.c

@@ -294,7 +294,29 @@ static int synaptics_pt_write(struct serio *serio, unsigned char c)
 	return 0;
 }
 
-static inline int synaptics_is_pt_packet(unsigned char *buf)
+static int synaptics_pt_start(struct serio *serio)
+{
+	struct psmouse *parent = serio_get_drvdata(serio->parent);
+	struct synaptics_data *priv = parent->private;
+
+	serio_pause_rx(parent->ps2dev.serio);
+	priv->pt_port = serio;
+	serio_continue_rx(parent->ps2dev.serio);
+
+	return 0;
+}
+
+static void synaptics_pt_stop(struct serio *serio)
+{
+	struct psmouse *parent = serio_get_drvdata(serio->parent);
+	struct synaptics_data *priv = parent->private;
+
+	serio_pause_rx(parent->ps2dev.serio);
+	priv->pt_port = NULL;
+	serio_continue_rx(parent->ps2dev.serio);
+}
+
+static int synaptics_is_pt_packet(unsigned char *buf)
 {
 	return (buf[0] & 0xFC) == 0x84 && (buf[3] & 0xCC) == 0xC4;
 }
@@ -315,9 +337,8 @@ static void synaptics_pass_pt_packet(struct serio *ptport, unsigned char *packet
 
 static void synaptics_pt_activate(struct psmouse *psmouse)
 {
-	struct serio *ptport = psmouse->ps2dev.serio->child;
-	struct psmouse *child = serio_get_drvdata(ptport);
 	struct synaptics_data *priv = psmouse->private;
+	struct psmouse *child = serio_get_drvdata(priv->pt_port);
 
 	/* adjust the touchpad to child's choice of protocol */
 	if (child) {
@@ -345,6 +366,8 @@ static void synaptics_pt_create(struct psmouse *psmouse)
 	strlcpy(serio->name, "Synaptics pass-through", sizeof(serio->name));
 	strlcpy(serio->phys, "synaptics-pt/serio0", sizeof(serio->name));
 	serio->write = synaptics_pt_write;
+	serio->start = synaptics_pt_start;
+	serio->stop = synaptics_pt_stop;
 	serio->parent = psmouse->ps2dev.serio;
 
 	psmouse->pt_activate = synaptics_pt_activate;
@@ -578,9 +601,10 @@ static psmouse_ret_t synaptics_process_byte(struct psmouse *psmouse)
 		if (unlikely(priv->pkt_type == SYN_NEWABS))
 			priv->pkt_type = synaptics_detect_pkt_type(psmouse);
 
-		if (SYN_CAP_PASS_THROUGH(priv->capabilities) && synaptics_is_pt_packet(psmouse->packet)) {
-			if (psmouse->ps2dev.serio->child)
-				synaptics_pass_pt_packet(psmouse->ps2dev.serio->child, psmouse->packet);
+		if (SYN_CAP_PASS_THROUGH(priv->capabilities) &&
+		    synaptics_is_pt_packet(psmouse->packet)) {
+			if (priv->pt_port)
+				synaptics_pass_pt_packet(priv->pt_port, psmouse->packet);
 		} else
 			synaptics_process_packet(psmouse);
 

drivers/input/mouse/synaptics.h

@@ -110,6 +110,8 @@ struct synaptics_data {
 	unsigned char pkt_type;			/* packet type - old, new, etc */
 	unsigned char mode;			/* current mode byte */
 	int scroll;
+
+	struct serio *pt_port;			/* Pass-through serio port */
 };
 
 void synaptics_module_init(void);