#include <linux/module.h>
#include <linux/serio.h>
#include <linux/errno.h>
-#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/kthread.h>
+#include <linux/workqueue.h>
#include <linux/mutex.h>
-#include <linux/freezer.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Serio abstraction core");
/*
* serio_mutex protects entire serio subsystem and is taken every time
- * serio port or driver registrered or unregistered.
+ * serio port or driver registered or unregistered.
*/
static DEFINE_MUTEX(serio_mutex);
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)
enum serio_event_type {
SERIO_RESCAN_PORT,
SERIO_RECONNECT_PORT,
- SERIO_RECONNECT_CHAIN,
+ SERIO_RECONNECT_SUBTREE,
SERIO_REGISTER_PORT,
SERIO_ATTACH_DRIVER,
};
static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
static LIST_HEAD(serio_event_list);
-static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
-static struct task_struct *serio_task;
-static int serio_queue_event(void *object, struct module *owner,
- enum serio_event_type event_type)
+static struct serio_event *serio_get_event(void)
{
+ struct serio_event *event = NULL;
unsigned long flags;
- struct serio_event *event;
- int retval = 0;
spin_lock_irqsave(&serio_event_lock, flags);
- /*
- * Scan event list for the other events for the same serio port,
- * starting with the most recent one. If event is the same we
- * do not need add new one. If event is of different type we
- * need to add this event and should not look further because
- * we need to preseve sequence of distinct events.
- */
- list_for_each_entry_reverse(event, &serio_event_list, node) {
- if (event->object == object) {
- if (event->type == event_type)
- goto out;
- break;
- }
- }
-
- event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
- if (!event) {
- pr_err("Not enough memory to queue event %d\n", event_type);
- retval = -ENOMEM;
- goto out;
- }
-
- if (!try_module_get(owner)) {
- pr_warning("Can't get module reference, dropping event %d\n",
- event_type);
- kfree(event);
- retval = -EINVAL;
- goto out;
+ if (!list_empty(&serio_event_list)) {
+ event = list_first_entry(&serio_event_list,
+ struct serio_event, node);
+ list_del_init(&event->node);
}
- event->type = event_type;
- event->object = object;
- event->owner = owner;
-
- list_add_tail(&event->node, &serio_event_list);
- wake_up(&serio_wait);
-
-out:
spin_unlock_irqrestore(&serio_event_lock, flags);
- return retval;
+ return event;
}
static void serio_free_event(struct serio_event *event)
kfree(event);
}
-static void serio_remove_duplicate_events(struct serio_event *event)
+static void serio_remove_duplicate_events(void *object,
+ enum serio_event_type type)
{
struct serio_event *e, *next;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
list_for_each_entry_safe(e, next, &serio_event_list, node) {
- if (event->object == e->object) {
+ if (object == e->object) {
/*
* If this event is of different type we should not
* look further - we only suppress duplicate events
* that were sent back-to-back.
*/
- if (event->type != e->type)
+ if (type != e->type)
break;
list_del_init(&e->node);
spin_unlock_irqrestore(&serio_event_lock, flags);
}
-
-static struct serio_event *serio_get_event(void)
-{
- struct serio_event *event = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&serio_event_lock, flags);
-
- if (!list_empty(&serio_event_list)) {
- event = list_first_entry(&serio_event_list,
- struct serio_event, node);
- list_del_init(&event->node);
- }
-
- spin_unlock_irqrestore(&serio_event_lock, flags);
- return event;
-}
-
-static void serio_handle_event(void)
+static void serio_handle_event(struct work_struct *work)
{
struct serio_event *event;
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:
break;
}
- serio_remove_duplicate_events(event);
+ serio_remove_duplicate_events(event->object, event->type);
serio_free_event(event);
}
mutex_unlock(&serio_mutex);
}
+static DECLARE_WORK(serio_event_work, serio_handle_event);
+
+static int serio_queue_event(void *object, struct module *owner,
+ enum serio_event_type event_type)
+{
+ unsigned long flags;
+ struct serio_event *event;
+ int retval = 0;
+
+ spin_lock_irqsave(&serio_event_lock, flags);
+
+ /*
+ * Scan event list for the other events for the same serio port,
+ * starting with the most recent one. If event is the same we
+ * do not need add new one. If event is of different type we
+ * need to add this event and should not look further because
+ * we need to preseve sequence of distinct events.
+ */
+ list_for_each_entry_reverse(event, &serio_event_list, node) {
+ if (event->object == object) {
+ if (event->type == event_type)
+ goto out;
+ break;
+ }
+ }
+
+ event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
+ if (!event) {
+ pr_err("Not enough memory to queue event %d\n", event_type);
+ retval = -ENOMEM;
+ goto out;
+ }
+
+ if (!try_module_get(owner)) {
+ pr_warning("Can't get module reference, dropping event %d\n",
+ event_type);
+ kfree(event);
+ retval = -EINVAL;
+ goto out;
+ }
+
+ event->type = event_type;
+ event->object = object;
+ event->owner = owner;
+
+ list_add_tail(&event->node, &serio_event_list);
+ queue_work(system_long_wq, &serio_event_work);
+
+out:
+ spin_unlock_irqrestore(&serio_event_lock, flags);
+ return retval;
+}
+
/*
* Remove all events that have been submitted for a given
* object, be it serio port or driver.
}
/*
- * 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)
{
return child;
}
-static int serio_thread(void *nothing)
-{
- do {
- serio_handle_event();
- wait_event_interruptible(serio_wait,
- kthread_should_stop() || !list_empty(&serio_event_list));
- } while (!kthread_should_stop());
-
- return 0;
-}
-
-
/*
* Serio port operations
*/
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);
+ serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
error = serio_bind_driver(serio, to_serio_driver(drv));
put_driver(drv);
+ serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
} else {
error = -EINVAL;
}
__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);
*/
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);
}
/*
- * 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);
}
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;
}
}
/*
- * 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;
+ }
+ }
+
+ /*
+ * 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;
}
- serio = serio->child;
- } while (serio);
+ } 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);
}
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);
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);
}
return error;
}
- serio_task = kthread_run(serio_thread, NULL, "kseriod");
- if (IS_ERR(serio_task)) {
- bus_unregister(&serio_bus);
- error = PTR_ERR(serio_task);
- pr_err("Failed to start kseriod, error: %d\n", error);
- return error;
- }
-
return 0;
}
static void __exit serio_exit(void)
{
bus_unregister(&serio_bus);
- kthread_stop(serio_task);
+
+ /*
+ * There should not be any outstanding events but work may
+ * still be scheduled so simply cancel it.
+ */
+ cancel_work_sync(&serio_event_work);
}
subsys_initcall(serio_init);
projects / mv-sheeva.git / blobdiff