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C

/*
* The Serio abstraction module
*
* Copyright (c) 1999-2004 Vojtech Pavlik
* Copyright (c) 2004 Dmitry Torokhov
* Copyright (c) 2003 Daniele Bellucci
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so either by
* e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
* Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
*/
#include <linux/stddef.h>
#include <linux/module.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/suspend.h>
#include <linux/slab.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Serio abstraction core");
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(serio_interrupt);
EXPORT_SYMBOL(serio_register_port);
EXPORT_SYMBOL(serio_register_port_delayed);
EXPORT_SYMBOL(serio_unregister_port);
EXPORT_SYMBOL(serio_unregister_port_delayed);
EXPORT_SYMBOL(serio_register_driver);
EXPORT_SYMBOL(serio_unregister_driver);
EXPORT_SYMBOL(serio_open);
EXPORT_SYMBOL(serio_close);
EXPORT_SYMBOL(serio_rescan);
EXPORT_SYMBOL(serio_reconnect);
static DECLARE_MUTEX(serio_sem); /* protects serio_list and serio_diriver_list */
static LIST_HEAD(serio_list);
static LIST_HEAD(serio_driver_list);
static unsigned int serio_no;
struct bus_type serio_bus = {
.name = "serio",
};
static void serio_find_driver(struct serio *serio);
static void serio_create_port(struct serio *serio);
static void serio_destroy_port(struct serio *serio);
static void serio_connect_port(struct serio *serio, struct serio_driver *drv);
static void serio_reconnect_port(struct serio *serio);
static void serio_disconnect_port(struct serio *serio);
static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
{
get_driver(&drv->driver);
drv->connect(serio, drv);
if (serio->drv) {
down_write(&serio_bus.subsys.rwsem);
serio->dev.driver = &drv->driver;
device_bind_driver(&serio->dev);
up_write(&serio_bus.subsys.rwsem);
return 1;
}
put_driver(&drv->driver);
return 0;
}
/* serio_find_driver() must be called with serio_sem down. */
static void serio_find_driver(struct serio *serio)
{
struct serio_driver *drv;
list_for_each_entry(drv, &serio_driver_list, node)
if (!drv->manual_bind)
if (serio_bind_driver(serio, drv))
break;
}
/*
* Serio event processing.
*/
struct serio_event {
int type;
struct serio *serio;
struct list_head node;
};
enum serio_event_type {
SERIO_RESCAN,
SERIO_RECONNECT,
SERIO_REGISTER_PORT,
SERIO_UNREGISTER_PORT,
};
static spinlock_t serio_event_lock = SPIN_LOCK_UNLOCKED; /* protects serio_event_list */
static LIST_HEAD(serio_event_list);
static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
static DECLARE_COMPLETION(serio_exited);
static int serio_pid;
static void serio_queue_event(struct serio *serio, int event_type)
{
unsigned long flags;
struct serio_event *event;
spin_lock_irqsave(&serio_event_lock, flags);
if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
event->type = event_type;
event->serio = serio;
list_add_tail(&event->node, &serio_event_list);
wake_up(&serio_wait);
}
spin_unlock_irqrestore(&serio_event_lock, flags);
}
static struct serio_event *serio_get_event(void)
{
struct serio_event *event;
struct list_head *node;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
if (list_empty(&serio_event_list)) {
spin_unlock_irqrestore(&serio_event_lock, flags);
return NULL;
}
node = serio_event_list.next;
event = container_of(node, struct serio_event, node);
list_del_init(node);
spin_unlock_irqrestore(&serio_event_lock, flags);
return event;
}
static void serio_handle_events(void)
{
struct serio_event *event;
while ((event = serio_get_event())) {
down(&serio_sem);
switch (event->type) {
case SERIO_REGISTER_PORT :
serio_create_port(event->serio);
serio_connect_port(event->serio, NULL);
break;
case SERIO_UNREGISTER_PORT :
serio_disconnect_port(event->serio);
serio_destroy_port(event->serio);
break;
case SERIO_RECONNECT :
serio_reconnect_port(event->serio);
break;
case SERIO_RESCAN :
serio_disconnect_port(event->serio);
serio_connect_port(event->serio, NULL);
break;
default:
break;
}
up(&serio_sem);
kfree(event);
}
}
static void serio_remove_pending_events(struct serio *serio)
{
struct list_head *node, *next;
struct serio_event *event;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
list_for_each_safe(node, next, &serio_event_list) {
event = container_of(node, struct serio_event, node);
if (event->serio == serio) {
list_del_init(node);
kfree(event);
}
}
spin_unlock_irqrestore(&serio_event_lock, flags);
}
static int serio_thread(void *nothing)
{
lock_kernel();
daemonize("kseriod");
allow_signal(SIGTERM);
do {
serio_handle_events();
wait_event_interruptible(serio_wait, !list_empty(&serio_event_list));
if (current->flags & PF_FREEZE)
refrigerator(PF_FREEZE);
} while (!signal_pending(current));
printk(KERN_DEBUG "serio: kseriod exiting\n");
unlock_kernel();
complete_and_exit(&serio_exited, 0);
}
/*
* Serio port operations
*/
static ssize_t serio_show_description(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%s\n", serio->name);
}
static ssize_t serio_rebind_driver(struct device *dev, const char *buf, size_t count)
{
struct serio *serio = to_serio_port(dev);
struct device_driver *drv;
int retval;
retval = down_interruptible(&serio_sem);
if (retval)
return retval;
retval = count;
if (!strncmp(buf, "none", count)) {
serio_disconnect_port(serio);
} else if (!strncmp(buf, "reconnect", count)) {
serio_reconnect_port(serio);
} else if (!strncmp(buf, "rescan", count)) {
serio_disconnect_port(serio);
serio_connect_port(serio, NULL);
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
serio_connect_port(serio, to_serio_driver(drv));
put_driver(drv);
} else {
retval = -EINVAL;
}
up(&serio_sem);
return retval;
}
static ssize_t serio_show_bind_mode(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
}
static ssize_t serio_set_bind_mode(struct device *dev, const char *buf, size_t count)
{
struct serio *serio = to_serio_port(dev);
int retval;
retval = count;
if (!strncmp(buf, "manual", count)) {
serio->manual_bind = 1;
} else if (!strncmp(buf, "auto", count)) {
serio->manual_bind = 0;
} else {
retval = -EINVAL;
}
return retval;
}
static struct device_attribute serio_device_attrs[] = {
__ATTR(description, S_IRUGO, serio_show_description, NULL),
__ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
__ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
__ATTR_NULL
};
static void serio_release_port(struct device *dev)
{
struct serio *serio = to_serio_port(dev);
kfree(serio);
module_put(THIS_MODULE);
}
static void serio_create_port(struct serio *serio)
{
try_module_get(THIS_MODULE);
spin_lock_init(&serio->lock);
list_add_tail(&serio->node, &serio_list);
snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id), "serio%d", serio_no++);
serio->dev.bus = &serio_bus;
serio->dev.release = serio_release_port;
if (serio->parent)
serio->dev.parent = &serio->parent->dev;
device_register(&serio->dev);
}
/*
* serio_destroy_port() completes deregistration process and removes
* port from the system
*/
static void serio_destroy_port(struct serio *serio)
{
struct serio_driver *drv = serio->drv;
unsigned long flags;
serio_remove_pending_events(serio);
list_del_init(&serio->node);
if (drv) {
drv->disconnect(serio);
down_write(&serio_bus.subsys.rwsem);
device_release_driver(&serio->dev);
up_write(&serio_bus.subsys.rwsem);
put_driver(&drv->driver);
}
if (serio->parent) {
spin_lock_irqsave(&serio->parent->lock, flags);
serio->parent->child = NULL;
spin_unlock_irqrestore(&serio->parent->lock, flags);
}
device_unregister(&serio->dev);
}
/*
* serio_connect_port() tries to bind the port and possible all its
* children to appropriate drivers. If driver passed in the function will not
* try otehr drivers when binding parent port.
*/
static void serio_connect_port(struct serio *serio, struct serio_driver *drv)
{
WARN_ON(serio->drv);
WARN_ON(serio->child);
if (drv)
serio_bind_driver(serio, drv);
else if (!serio->manual_bind)
serio_find_driver(serio);
/* Ok, now bind children, if any */
while (serio->child) {
serio = serio->child;
WARN_ON(serio->drv);
WARN_ON(serio->child);
serio_create_port(serio);
if (!serio->manual_bind) {
/*
* With children we just _prefer_ passed in driver,
* but we will try other options in case preferred
* is not the one
*/
if (!drv || !serio_bind_driver(serio, drv))
serio_find_driver(serio);
}
}
}
/*
*
*/
static void serio_reconnect_port(struct serio *serio)
{
do {
if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
serio_disconnect_port(serio);
serio_connect_port(serio, NULL);
/* Ok, old children are now gone, we are done */
break;
}
serio = serio->child;
} while (serio);
}
/*
* serio_disconnect_port() unbinds a port from its driver. As a side effect
* all child ports are unbound and destroyed.
*/
static void serio_disconnect_port(struct serio *serio)
{
struct serio_driver *drv = serio->drv;
struct serio *s;
if (serio->child) {
/*
* Children ports should be disconnected and destroyed
* first, staring with the leaf one, since we don't want
* to do recursion
*/
do {
s = serio->child;
} while (s->child);
while (s != serio) {
s = s->parent;
serio_destroy_port(s->child);
}
}
/*
* Ok, no children left, now disconnect this port
*/
if (drv) {
drv->disconnect(serio);
down_write(&serio_bus.subsys.rwsem);
device_release_driver(&serio->dev);
up_write(&serio_bus.subsys.rwsem);
put_driver(&drv->driver);
}
}
void serio_rescan(struct serio *serio)
{
serio_queue_event(serio, SERIO_RESCAN);
}
void serio_reconnect(struct serio *serio)
{
serio_queue_event(serio, SERIO_RECONNECT);
}
void serio_register_port(struct serio *serio)
{
down(&serio_sem);
serio_create_port(serio);
serio_connect_port(serio, NULL);
up(&serio_sem);
}
/*
* Submits register request to kseriod for subsequent execution.
* Can be used when it is not obvious whether the serio_sem is
* taken or not and when delayed execution is feasible.
*/
void serio_register_port_delayed(struct serio *serio)
{
serio_queue_event(serio, SERIO_REGISTER_PORT);
}
void serio_unregister_port(struct serio *serio)
{
down(&serio_sem);
serio_disconnect_port(serio);
serio_destroy_port(serio);
up(&serio_sem);
}
/*
* Submits unregister request to kseriod for subsequent execution.
* Can be used when it is not obvious whether the serio_sem is
* taken or not and when delayed execution is feasible.
*/
void serio_unregister_port_delayed(struct serio *serio)
{
serio_queue_event(serio, SERIO_UNREGISTER_PORT);
}
/*
* Serio driver operations
*/
static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
{
struct serio_driver *driver = to_serio_driver(drv);
return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
}
static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
{
struct serio_driver *serio_drv = to_serio_driver(drv);
return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
}
static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
{
struct serio_driver *serio_drv = to_serio_driver(drv);
int retval;
retval = count;
if (!strncmp(buf, "manual", count)) {
serio_drv->manual_bind = 1;
} else if (!strncmp(buf, "auto", count)) {
serio_drv->manual_bind = 0;
} else {
retval = -EINVAL;
}
return retval;
}
static struct driver_attribute serio_driver_attrs[] = {
__ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
__ATTR(bind_mode, S_IWUSR | S_IRUGO,
serio_driver_show_bind_mode, serio_driver_set_bind_mode),
__ATTR_NULL
};
void serio_register_driver(struct serio_driver *drv)
{
struct serio *serio;
down(&serio_sem);
list_add_tail(&drv->node, &serio_driver_list);
drv->driver.bus = &serio_bus;
driver_register(&drv->driver);
if (drv->manual_bind)
goto out;
start_over:
list_for_each_entry(serio, &serio_list, node) {
if (!serio->drv) {
serio_connect_port(serio, drv);
/*
* if new child appeared then the list is changed,
* we need to start over
*/
if (serio->child)
goto start_over;
}
}
out:
up(&serio_sem);
}
void serio_unregister_driver(struct serio_driver *drv)
{
struct serio *serio;
down(&serio_sem);
list_del_init(&drv->node);
start_over:
list_for_each_entry(serio, &serio_list, node) {
if (serio->drv == drv) {
serio_disconnect_port(serio);
serio_connect_port(serio, NULL);
/* we could've deleted some ports, restart */
goto start_over;
}
}
driver_unregister(&drv->driver);
up(&serio_sem);
}
/* called from serio_driver->connect/disconnect methods under serio_sem */
int serio_open(struct serio *serio, struct serio_driver *drv)
{
serio_pause_rx(serio);
serio->drv = drv;
serio_continue_rx(serio);
if (serio->open && serio->open(serio)) {
serio_pause_rx(serio);
serio->drv = NULL;
serio_continue_rx(serio);
return -1;
}
return 0;
}
/* called from serio_driver->connect/disconnect methods under serio_sem */
void serio_close(struct serio *serio)
{
if (serio->close)
serio->close(serio);
serio_pause_rx(serio);
serio->drv = NULL;
serio_continue_rx(serio);
}
irqreturn_t serio_interrupt(struct serio *serio,
unsigned char data, unsigned int dfl, struct pt_regs *regs)
{
unsigned long flags;
irqreturn_t ret = IRQ_NONE;
spin_lock_irqsave(&serio->lock, flags);
if (likely(serio->drv)) {
ret = serio->drv->interrupt(serio, data, dfl, regs);
} else {
if (!dfl) {
if ((serio->type != SERIO_8042 &&
serio->type != SERIO_8042_XL) || (data == 0xaa)) {
serio_rescan(serio);
ret = IRQ_HANDLED;
}
}
}
spin_unlock_irqrestore(&serio->lock, flags);
return ret;
}
static int __init serio_init(void)
{
if (!(serio_pid = kernel_thread(serio_thread, NULL, CLONE_KERNEL))) {
printk(KERN_WARNING "serio: Failed to start kseriod\n");
return -1;
}
serio_bus.dev_attrs = serio_device_attrs;
serio_bus.drv_attrs = serio_driver_attrs;
bus_register(&serio_bus);
return 0;
}
static void __exit serio_exit(void)
{
bus_unregister(&serio_bus);
kill_proc(serio_pid, SIGTERM, 1);
wait_for_completion(&serio_exited);
}
module_init(serio_init);
module_exit(serio_exit);