7 files changed, 412 insertions, 45 deletions

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index 3bfe8fafc6a..6256233d2bf 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -226,4 +226,13 @@ config SERIO_AMS_DELTA
 	  To compile this driver as a module, choose M here;
 	  the module will be called ams_delta_serio.
 
+config SERIO_PS2MULT
+	tristate "TQC PS/2 multiplexer"
+	help
+	  Say Y here if you have the PS/2 line multiplexer like the one
+	  present on TQC boads.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ps2mult.
+
 endif
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 84c80bf7185..dbbe37616c9 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SERIO_GSCPS2)	+= gscps2.o
 obj-$(CONFIG_HP_SDC)		+= hp_sdc.o
 obj-$(CONFIG_HIL_MLC)		+= hp_sdc_mlc.o hil_mlc.o
 obj-$(CONFIG_SERIO_PCIPS2)	+= pcips2.o
+obj-$(CONFIG_SERIO_PS2MULT)	+= ps2mult.o
 obj-$(CONFIG_SERIO_MACEPS2)	+= maceps2.o
 obj-$(CONFIG_SERIO_LIBPS2)	+= libps2.o
 obj-$(CONFIG_SERIO_RAW)		+= serio_raw.o
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index f5851316048..18db5a8c747 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -1063,7 +1063,7 @@ static long i8042_panic_blink(int state)
 #ifdef CONFIG_X86
 static void i8042_dritek_enable(void)
 {
-	char param = 0x90;
+	unsigned char param = 0x90;
 	int error;
 
 	error = i8042_command(&param, 0x1059);
diff --git a/drivers/input/serio/ps2mult.c b/drivers/input/serio/ps2mult.c
new file mode 100644
index 00000000000..6bce22e4e49
--- /dev/null
+++ b/drivers/input/serio/ps2mult.c
@@ -0,0 +1,318 @@
+/*
+ * TQC PS/2 Multiplexer driver
+ *
+ * Copyright (C) 2010 Dmitry Eremin-Solenikov
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+
+MODULE_AUTHOR("Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>");
+MODULE_DESCRIPTION("TQC PS/2 Multiplexer driver");
+MODULE_LICENSE("GPL");
+
+#define PS2MULT_KB_SELECTOR		0xA0
+#define PS2MULT_MS_SELECTOR		0xA1
+#define PS2MULT_ESCAPE			0x7D
+#define PS2MULT_BSYNC			0x7E
+#define PS2MULT_SESSION_START		0x55
+#define PS2MULT_SESSION_END		0x56
+
+struct ps2mult_port {
+	struct serio *serio;
+	unsigned char sel;
+	bool registered;
+};
+
+#define PS2MULT_NUM_PORTS	2
+#define PS2MULT_KBD_PORT	0
+#define PS2MULT_MOUSE_PORT	1
+
+struct ps2mult {
+	struct serio *mx_serio;
+	struct ps2mult_port ports[PS2MULT_NUM_PORTS];
+
+	spinlock_t lock;
+	struct ps2mult_port *in_port;
+	struct ps2mult_port *out_port;
+	bool escape;
+};
+
+/* First MUST come PS2MULT_NUM_PORTS selectors */
+static const unsigned char ps2mult_controls[] = {
+	PS2MULT_KB_SELECTOR, PS2MULT_MS_SELECTOR,
+	PS2MULT_ESCAPE, PS2MULT_BSYNC,
+	PS2MULT_SESSION_START, PS2MULT_SESSION_END,
+};
+
+static const struct serio_device_id ps2mult_serio_ids[] = {
+	{
+		.type	= SERIO_RS232,
+		.proto	= SERIO_PS2MULT,
+		.id	= SERIO_ANY,
+		.extra	= SERIO_ANY,
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, ps2mult_serio_ids);
+
+static void ps2mult_select_port(struct ps2mult *psm, struct ps2mult_port *port)
+{
+	struct serio *mx_serio = psm->mx_serio;
+
+	serio_write(mx_serio, port->sel);
+	psm->out_port = port;
+	dev_dbg(&mx_serio->dev, "switched to sel %02x\n", port->sel);
+}
+
+static int ps2mult_serio_write(struct serio *serio, unsigned char data)
+{
+	struct serio *mx_port = serio->parent;
+	struct ps2mult *psm = serio_get_drvdata(mx_port);
+	struct ps2mult_port *port = serio->port_data;
+	bool need_escape;
+	unsigned long flags;
+
+	spin_lock_irqsave(&psm->lock, flags);
+
+	if (psm->out_port != port)
+		ps2mult_select_port(psm, port);
+
+	need_escape = memchr(ps2mult_controls, data, sizeof(ps2mult_controls));
+
+	dev_dbg(&serio->dev,
+		"write: %s%02x\n", need_escape ? "ESC " : "", data);
+
+	if (need_escape)
+		serio_write(mx_port, PS2MULT_ESCAPE);
+
+	serio_write(mx_port, data);
+
+	spin_unlock_irqrestore(&psm->lock, flags);
+
+	return 0;
+}
+
+static int ps2mult_serio_start(struct serio *serio)
+{
+	struct ps2mult *psm = serio_get_drvdata(serio->parent);
+	struct ps2mult_port *port = serio->port_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&psm->lock, flags);
+	port->registered = true;
+	spin_unlock_irqrestore(&psm->lock, flags);
+
+	return 0;
+}
+
+static void ps2mult_serio_stop(struct serio *serio)
+{
+	struct ps2mult *psm = serio_get_drvdata(serio->parent);
+	struct ps2mult_port *port = serio->port_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&psm->lock, flags);
+	port->registered = false;
+	spin_unlock_irqrestore(&psm->lock, flags);
+}
+
+static int ps2mult_create_port(struct ps2mult *psm, int i)
+{
+	struct serio *mx_serio = psm->mx_serio;
+	struct serio *serio;
+
+	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+	if (!serio)
+		return -ENOMEM;
+
+	strlcpy(serio->name, "TQC PS/2 Multiplexer", sizeof(serio->name));
+	snprintf(serio->phys, sizeof(serio->phys),
+		 "%s/port%d", mx_serio->phys, i);
+	serio->id.type = SERIO_8042;
+	serio->write = ps2mult_serio_write;
+	serio->start = ps2mult_serio_start;
+	serio->stop = ps2mult_serio_stop;
+	serio->parent = psm->mx_serio;
+	serio->port_data = &psm->ports[i];
+
+	psm->ports[i].serio = serio;
+
+	return 0;
+}
+
+static void ps2mult_reset(struct ps2mult *psm)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&psm->lock, flags);
+
+	serio_write(psm->mx_serio, PS2MULT_SESSION_END);
+	serio_write(psm->mx_serio, PS2MULT_SESSION_START);
+
+	ps2mult_select_port(psm, &psm->ports[PS2MULT_KBD_PORT]);
+
+	spin_unlock_irqrestore(&psm->lock, flags);
+}
+
+static int ps2mult_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct ps2mult *psm;
+	int i;
+	int error;
+
+	if (!serio->write)
+		return -EINVAL;
+
+	psm = kzalloc(sizeof(*psm), GFP_KERNEL);
+	if (!psm)
+		return -ENOMEM;
+
+	spin_lock_init(&psm->lock);
+	psm->mx_serio = serio;
+
+	for (i = 0; i < PS2MULT_NUM_PORTS; i++) {
+		psm->ports[i].sel = ps2mult_controls[i];
+		error = ps2mult_create_port(psm, i);
+		if (error)
+			goto err_out;
+	}
+
+	psm->in_port = psm->out_port = &psm->ports[PS2MULT_KBD_PORT];
+
+	serio_set_drvdata(serio, psm);
+	error = serio_open(serio, drv);
+	if (error)
+		goto err_out;
+
+	ps2mult_reset(psm);
+
+	for (i = 0; i <  PS2MULT_NUM_PORTS; i++) {
+		struct serio *s = psm->ports[i].serio;
+
+		dev_info(&serio->dev, "%s port at %s\n", s->name, serio->phys);
+		serio_register_port(s);
+	}
+
+	return 0;
+
+err_out:
+	while (--i >= 0)
+		kfree(psm->ports[i].serio);
+	kfree(serio);
+	return error;
+}
+
+static void ps2mult_disconnect(struct serio *serio)
+{
+	struct ps2mult *psm = serio_get_drvdata(serio);
+
+	/* Note that serio core already take care of children ports */
+	serio_write(serio, PS2MULT_SESSION_END);
+	serio_close(serio);
+	kfree(psm);
+
+	serio_set_drvdata(serio, NULL);
+}
+
+static int ps2mult_reconnect(struct serio *serio)
+{
+	struct ps2mult *psm = serio_get_drvdata(serio);
+
+	ps2mult_reset(psm);
+
+	return 0;
+}
+
+static irqreturn_t ps2mult_interrupt(struct serio *serio,
+				     unsigned char data, unsigned int dfl)
+{
+	struct ps2mult *psm = serio_get_drvdata(serio);
+	struct ps2mult_port *in_port;
+	unsigned long flags;
+
+	dev_dbg(&serio->dev, "Received %02x flags %02x\n", data, dfl);
+
+	spin_lock_irqsave(&psm->lock, flags);
+
+	if (psm->escape) {
+		psm->escape = false;
+		in_port = psm->in_port;
+		if (in_port->registered)
+			serio_interrupt(in_port->serio, data, dfl);
+		goto out;
+	}
+
+	switch (data) {
+	case PS2MULT_ESCAPE:
+		dev_dbg(&serio->dev, "ESCAPE\n");
+		psm->escape = true;
+		break;
+
+	case PS2MULT_BSYNC:
+		dev_dbg(&serio->dev, "BSYNC\n");
+		psm->in_port = psm->out_port;
+		break;
+
+	case PS2MULT_SESSION_START:
+		dev_dbg(&serio->dev, "SS\n");
+		break;
+
+	case PS2MULT_SESSION_END:
+		dev_dbg(&serio->dev, "SE\n");
+		break;
+
+	case PS2MULT_KB_SELECTOR:
+		dev_dbg(&serio->dev, "KB\n");
+		psm->in_port = &psm->ports[PS2MULT_KBD_PORT];
+		break;
+
+	case PS2MULT_MS_SELECTOR:
+		dev_dbg(&serio->dev, "MS\n");
+		psm->in_port = &psm->ports[PS2MULT_MOUSE_PORT];
+		break;
+
+	default:
+		in_port = psm->in_port;
+		if (in_port->registered)
+			serio_interrupt(in_port->serio, data, dfl);
+		break;
+	}
+
+ out:
+	spin_unlock_irqrestore(&psm->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static struct serio_driver ps2mult_drv = {
+	.driver		= {
+		.name	= "ps2mult",
+	},
+	.description	= "TQC PS/2 Multiplexer driver",
+	.id_table	= ps2mult_serio_ids,
+	.interrupt	= ps2mult_interrupt,
+	.connect	= ps2mult_connect,
+	.disconnect	= ps2mult_disconnect,
+	.reconnect	= ps2mult_reconnect,
+};
+
+static int __init ps2mult_init(void)
+{
+	return serio_register_driver(&ps2mult_drv);
+}
+
+static void __exit ps2mult_exit(void)
+{
+	serio_unregister_driver(&ps2mult_drv);
+}
+
+module_init(ps2mult_init);
+module_exit(ps2mult_exit);
diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index c3b626e9eae..405bf214527 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -37,7 +37,6 @@
 #include <linux/slab.h>
 #include <linux/kthread.h>
 #include <linux/mutex.h>
-#include <linux/freezer.h>
 
 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION("Serio abstraction core");
@@ -56,7 +55,7 @@ static struct bus_type serio_bus;
 static void serio_add_port(struct serio *serio);
 static int serio_reconnect_port(struct serio *serio);
 static void serio_disconnect_port(struct serio *serio);
-static void serio_reconnect_chain(struct serio *serio);
+static void serio_reconnect_subtree(struct serio *serio);
 static void serio_attach_driver(struct serio_driver *drv);
 
 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
@@ -152,7 +151,7 @@ static void serio_find_driver(struct serio *serio)
 enum serio_event_type {
 	SERIO_RESCAN_PORT,
 	SERIO_RECONNECT_PORT,
-	SERIO_RECONNECT_CHAIN,
+	SERIO_RECONNECT_SUBTREE,
 	SERIO_REGISTER_PORT,
 	SERIO_ATTACH_DRIVER,
 };
@@ -292,8 +291,8 @@ static void serio_handle_event(void)
 			serio_find_driver(event->object);
 			break;
 
-		case SERIO_RECONNECT_CHAIN:
-			serio_reconnect_chain(event->object);
+		case SERIO_RECONNECT_SUBTREE:
+			serio_reconnect_subtree(event->object);
 			break;
 
 		case SERIO_ATTACH_DRIVER:
@@ -330,12 +329,10 @@ static void serio_remove_pending_events(void *object)
 }
 
 /*
- * Destroy child serio port (if any) that has not been fully registered yet.
+ * Locate child serio port (if any) that has not been fully registered yet.
  *
- * Note that we rely on the fact that port can have only one child and therefore
- * only one child registration request can be pending. Additionally, children
- * are registered by driver's connect() handler so there can't be a grandchild
- * pending registration together with a child.
+ * Children are registered by driver's connect() handler so there can't be a
+ * grandchild pending registration together with a child.
  */
 static struct serio *serio_get_pending_child(struct serio *parent)
 {
@@ -449,7 +446,7 @@ static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *
 	if (!strncmp(buf, "none", count)) {
 		serio_disconnect_port(serio);
 	} else if (!strncmp(buf, "reconnect", count)) {
-		serio_reconnect_chain(serio);
+		serio_reconnect_subtree(serio);
 	} else if (!strncmp(buf, "rescan", count)) {
 		serio_disconnect_port(serio);
 		serio_find_driver(serio);
@@ -516,6 +513,8 @@ static void serio_init_port(struct serio *serio)
 	__module_get(THIS_MODULE);
 
 	INIT_LIST_HEAD(&serio->node);
+	INIT_LIST_HEAD(&serio->child_node);
+	INIT_LIST_HEAD(&serio->children);
 	spin_lock_init(&serio->lock);
 	mutex_init(&serio->drv_mutex);
 	device_initialize(&serio->dev);
@@ -538,12 +537,13 @@ static void serio_init_port(struct serio *serio)
  */
 static void serio_add_port(struct serio *serio)
 {
+	struct serio *parent = serio->parent;
 	int error;
 
-	if (serio->parent) {
-		serio_pause_rx(serio->parent);
-		serio->parent->child = serio;
-		serio_continue_rx(serio->parent);
+	if (parent) {
+		serio_pause_rx(parent);
+		list_add_tail(&serio->child_node, &parent->children);
+		serio_continue_rx(parent);
 	}
 
 	list_add_tail(&serio->node, &serio_list);
@@ -559,15 +559,14 @@ static void serio_add_port(struct serio *serio)
 }
 
 /*
- * serio_destroy_port() completes deregistration process and removes
+ * serio_destroy_port() completes unregistration process and removes
  * port from the system
  */
 static void serio_destroy_port(struct serio *serio)
 {
 	struct serio *child;
 
-	child = serio_get_pending_child(serio);
-	if (child) {
+	while ((child = serio_get_pending_child(serio)) != NULL) {
 		serio_remove_pending_events(child);
 		put_device(&child->dev);
 	}
@@ -577,7 +576,7 @@ static void serio_destroy_port(struct serio *serio)
 
 	if (serio->parent) {
 		serio_pause_rx(serio->parent);
-		serio->parent->child = NULL;
+		list_del_init(&serio->child_node);
 		serio_continue_rx(serio->parent);
 		serio->parent = NULL;
 	}
@@ -609,46 +608,82 @@ static int serio_reconnect_port(struct serio *serio)
 }
 
 /*
- * Reconnect serio port and all its children (re-initialize attached devices)
+ * Reconnect serio port and all its children (re-initialize attached
+ * devices).
  */
-static void serio_reconnect_chain(struct serio *serio)
+static void serio_reconnect_subtree(struct serio *root)
 {
+	struct serio *s = root;
+	int error;
+
 	do {
-		if (serio_reconnect_port(serio)) {
-			/* Ok, old children are now gone, we are done */
-			break;
+		error = serio_reconnect_port(s);
+		if (!error) {
+			/*
+			 * Reconnect was successful, move on to do the
+			 * first child.
+			 */
+			if (!list_empty(&s->children)) {
+				s = list_first_entry(&s->children,
+						     struct serio, child_node);
+				continue;
+			}
 		}
-		serio = serio->child;
-	} while (serio);
+
+		/*
+		 * Either it was a leaf node or reconnect failed and it
+		 * became a leaf node. Continue reconnecting starting with
+		 * the next sibling of the parent node.
+		 */
+		while (s != root) {
+			struct serio *parent = s->parent;
+
+			if (!list_is_last(&s->child_node, &parent->children)) {
+				s = list_entry(s->child_node.next,
+					       struct serio, child_node);
+				break;
+			}
+
+			s = parent;
+		}
+	} while (s != root);
 }
 
 /*
  * serio_disconnect_port() unbinds a port from its driver. As a side effect
- * all child ports are unbound and destroyed.
+ * all children ports are unbound and destroyed.
  */
 static void serio_disconnect_port(struct serio *serio)
 {
-	struct serio *s, *parent;
+	struct serio *s = serio;
+
+	/*
+	 * Children ports should be disconnected and destroyed
+	 * first; we travel the tree in depth-first order.
+	 */
+	while (!list_empty(&serio->children)) {
+
+		/* Locate a leaf */
+		while (!list_empty(&s->children))
+			s = list_first_entry(&s->children,
+					     struct serio, child_node);
 
-	if (serio->child) {
 		/*
-		 * Children ports should be disconnected and destroyed
-		 * first, staring with the leaf one, since we don't want
-		 * to do recursion
+		 * Prune this leaf node unless it is the one we
+		 * started with.
 		 */
-		for (s = serio; s->child; s = s->child)
-			/* empty */;
-
-		do {
-			parent = s->parent;
+		if (s != serio) {
+			struct serio *parent = s->parent;
 
 			device_release_driver(&s->dev);
 			serio_destroy_port(s);
-		} while ((s = parent) != serio);
+
+			s = parent;
+		}
 	}
 
 	/*
-	 * Ok, no children left, now disconnect this port
+	 * OK, no children left, now disconnect this port.
 	 */
 	device_release_driver(&serio->dev);
 }
@@ -661,7 +696,7 @@ EXPORT_SYMBOL(serio_rescan);
 
 void serio_reconnect(struct serio *serio)
 {
-	serio_queue_event(serio, NULL, SERIO_RECONNECT_CHAIN);
+	serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
 }
 EXPORT_SYMBOL(serio_reconnect);
 
@@ -689,14 +724,16 @@ void serio_unregister_port(struct serio *serio)
 EXPORT_SYMBOL(serio_unregister_port);
 
 /*
- * Safely unregisters child port if one is present.
+ * Safely unregisters children ports if they are present.
  */
 void serio_unregister_child_port(struct serio *serio)
 {
+	struct serio *s, *next;
+
 	mutex_lock(&serio_mutex);
-	if (serio->child) {
-		serio_disconnect_port(serio->child);
-		serio_destroy_port(serio->child);
+	list_for_each_entry_safe(s, next, &serio->children, child_node) {
+		serio_disconnect_port(s);
+		serio_destroy_port(s);
 	}
 	mutex_unlock(&serio_mutex);
 }
diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c
index 99866485444..cd82bb12591 100644
--- a/drivers/input/serio/serio_raw.c
+++ b/drivers/input/serio/serio_raw.c
@@ -243,6 +243,7 @@ static const struct file_operations serio_raw_fops = {
 	.write =	serio_raw_write,
 	.poll =		serio_raw_poll,
 	.fasync =	serio_raw_fasync,
+	.llseek = noop_llseek,
 };
 
 
diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
index 6d345112bcb..6e362de3f41 100644
--- a/drivers/input/serio/serport.c
+++ b/drivers/input/serio/serport.c
@@ -165,6 +165,7 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
 	serio->open = serport_serio_open;
 	serio->close = serport_serio_close;
 	serio->port_data = serport;
+	serio->dev.parent = tty->dev;
 
 	serio_register_port(serport->serio);
 	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));