blob: 0beacb77ee18372585282a5aab58b04f06a615a9 [file] [log] [blame]
/*
* 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/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_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);
/*
* serio_sem protects entire serio subsystem and is taken every time
* serio port or driver registrered or unregistered.
*/
static DECLARE_MUTEX(serio_sem);
static LIST_HEAD(serio_list);
static struct bus_type serio_bus = {
.name = "serio",
};
static void serio_add_port(struct serio *serio);
static void serio_destroy_port(struct serio *serio);
static void serio_reconnect_port(struct serio *serio);
static void serio_disconnect_port(struct serio *serio);
static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
{
while (ids->type || ids->proto) {
if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
(ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
(ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
(ids->id == SERIO_ANY || ids->id == serio->id.id))
return 1;
ids++;
}
return 0;
}
/*
* Basic serio -> driver core mappings
*/
static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
{
down_write(&serio_bus.subsys.rwsem);
if (serio_match_port(drv->id_table, serio)) {
serio->dev.driver = &drv->driver;
if (drv->connect(serio, drv)) {
serio->dev.driver = NULL;
goto out;
}
device_bind_driver(&serio->dev);
}
out:
up_write(&serio_bus.subsys.rwsem);
}
static void serio_release_driver(struct serio *serio)
{
down_write(&serio_bus.subsys.rwsem);
device_release_driver(&serio->dev);
up_write(&serio_bus.subsys.rwsem);
}
static void serio_find_driver(struct serio *serio)
{
down_write(&serio_bus.subsys.rwsem);
device_attach(&serio->dev);
up_write(&serio_bus.subsys.rwsem);
}
/*
* Serio event processing.
*/
enum serio_event_type {
SERIO_RESCAN,
SERIO_RECONNECT,
SERIO_REGISTER_PORT,
SERIO_UNREGISTER_PORT,
SERIO_REGISTER_DRIVER,
};
struct serio_event {
enum serio_event_type type;
void *object;
struct module *owner;
struct list_head node;
};
static DEFINE_SPINLOCK(serio_event_lock); /* 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(void *object, struct module *owner,
enum serio_event_type event_type)
{
unsigned long flags;
struct serio_event *event;
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;
}
}
if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
if (!try_module_get(owner)) {
printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
goto out;
}
event->type = event_type;
event->object = object;
event->owner = owner;
list_add_tail(&event->node, &serio_event_list);
wake_up(&serio_wait);
} else {
printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
}
out:
spin_unlock_irqrestore(&serio_event_lock, flags);
}
static void serio_free_event(struct serio_event *event)
{
module_put(event->owner);
kfree(event);
}
static void serio_remove_duplicate_events(struct serio_event *event)
{
struct list_head *node, *next;
struct serio_event *e;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
list_for_each_safe(node, next, &serio_event_list) {
e = list_entry(node, struct serio_event, node);
if (event->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)
break;
list_del_init(node);
serio_free_event(e);
}
}
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 = list_entry(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;
struct serio_driver *serio_drv;
down(&serio_sem);
while ((event = serio_get_event())) {
switch (event->type) {
case SERIO_REGISTER_PORT:
serio_add_port(event->object);
break;
case SERIO_UNREGISTER_PORT:
serio_disconnect_port(event->object);
serio_destroy_port(event->object);
break;
case SERIO_RECONNECT:
serio_reconnect_port(event->object);
break;
case SERIO_RESCAN:
serio_disconnect_port(event->object);
serio_find_driver(event->object);
break;
case SERIO_REGISTER_DRIVER:
serio_drv = event->object;
driver_register(&serio_drv->driver);
break;
default:
break;
}
serio_remove_duplicate_events(event);
serio_free_event(event);
}
up(&serio_sem);
}
/*
* Remove all events that have been submitted for a given serio port.
*/
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 = list_entry(node, struct serio_event, node);
if (event->object == serio) {
list_del_init(node);
serio_free_event(event);
}
}
spin_unlock_irqrestore(&serio_event_lock, flags);
}
/*
* Destroy 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.
*/
static struct serio *serio_get_pending_child(struct serio *parent)
{
struct serio_event *event;
struct serio *serio, *child = NULL;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
list_for_each_entry(event, &serio_event_list, node) {
if (event->type == SERIO_REGISTER_PORT) {
serio = event->object;
if (serio->parent == parent) {
child = serio;
break;
}
}
}
spin_unlock_irqrestore(&serio_event_lock, flags);
return child;
}
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));
try_to_freeze(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_show_id_type(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%02x\n", serio->id.type);
}
static ssize_t serio_show_id_proto(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%02x\n", serio->id.proto);
}
static ssize_t serio_show_id_id(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%02x\n", serio->id.id);
}
static ssize_t serio_show_id_extra(struct device *dev, char *buf)
{
struct serio *serio = to_serio_port(dev);
return sprintf(buf, "%02x\n", serio->id.extra);
}
static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
static struct attribute *serio_device_id_attrs[] = {
&dev_attr_type.attr,
&dev_attr_proto.attr,
&dev_attr_id.attr,
&dev_attr_extra.attr,
NULL
};
static struct attribute_group serio_id_attr_group = {
.name = "id",
.attrs = serio_device_id_attrs,
};
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_find_driver(serio);
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
serio_bind_driver(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);
}
/*
* Prepare serio port for registration.
*/
static void serio_init_port(struct serio *serio)
{
static atomic_t serio_no = ATOMIC_INIT(0);
__module_get(THIS_MODULE);
spin_lock_init(&serio->lock);
init_MUTEX(&serio->drv_sem);
device_initialize(&serio->dev);
snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
"serio%ld", (long)atomic_inc_return(&serio_no) - 1);
serio->dev.bus = &serio_bus;
serio->dev.release = serio_release_port;
if (serio->parent)
serio->dev.parent = &serio->parent->dev;
}
/*
* Complete serio port registration.
* Driver core will attempt to find appropriate driver for the port.
*/
static void serio_add_port(struct serio *serio)
{
if (serio->parent) {
serio_pause_rx(serio->parent);
serio->parent->child = serio;
serio_continue_rx(serio->parent);
}
list_add_tail(&serio->node, &serio_list);
if (serio->start)
serio->start(serio);
device_add(&serio->dev);
sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
serio->registered = 1;
}
/*
* serio_destroy_port() completes deregistration 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) {
serio_remove_pending_events(child);
put_device(&child->dev);
}
if (serio->stop)
serio->stop(serio);
if (serio->parent) {
serio_pause_rx(serio->parent);
serio->parent->child = NULL;
serio_continue_rx(serio->parent);
serio->parent = NULL;
}
if (serio->registered) {
sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
device_del(&serio->dev);
list_del_init(&serio->node);
serio->registered = 0;
}
serio_remove_pending_events(serio);
put_device(&serio->dev);
}
/*
* Reconnect serio port and all its children (re-initialize attached devices)
*/
static void serio_reconnect_port(struct serio *serio)
{
do {
if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
serio_disconnect_port(serio);
serio_find_driver(serio);
/* 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 *s, *parent;
if (serio->child) {
/*
* Children ports should be disconnected and destroyed
* first, staring with the leaf one, since we don't want
* to do recursion
*/
for (s = serio; s->child; s = s->child)
/* empty */;
do {
parent = s->parent;
serio_release_driver(s);
serio_destroy_port(s);
} while ((s = parent) != serio);
}
/*
* Ok, no children left, now disconnect this port
*/
serio_release_driver(serio);
}
void serio_rescan(struct serio *serio)
{
serio_queue_event(serio, NULL, SERIO_RESCAN);
}
void serio_reconnect(struct serio *serio)
{
serio_queue_event(serio, NULL, SERIO_RECONNECT);
}
/*
* Submits register request to kseriod for subsequent execution.
* Note that port registration is always asynchronous.
*/
void __serio_register_port(struct serio *serio, struct module *owner)
{
serio_init_port(serio);
serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
}
/*
* Synchronously unregisters serio port.
*/
void serio_unregister_port(struct serio *serio)
{
down(&serio_sem);
serio_disconnect_port(serio);
serio_destroy_port(serio);
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_unregister_port_delayed(struct serio *serio, struct module *owner)
{
serio_queue_event(serio, owner, 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
};
static int serio_driver_probe(struct device *dev)
{
struct serio *serio = to_serio_port(dev);
struct serio_driver *drv = to_serio_driver(dev->driver);
return drv->connect(serio, drv);
}
static int serio_driver_remove(struct device *dev)
{
struct serio *serio = to_serio_port(dev);
struct serio_driver *drv = to_serio_driver(dev->driver);
drv->disconnect(serio);
return 0;
}
void __serio_register_driver(struct serio_driver *drv, struct module *owner)
{
drv->driver.bus = &serio_bus;
drv->driver.probe = serio_driver_probe;
drv->driver.remove = serio_driver_remove;
serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
}
void serio_unregister_driver(struct serio_driver *drv)
{
struct serio *serio;
down(&serio_sem);
drv->manual_bind = 1; /* so serio_find_driver ignores it */
start_over:
list_for_each_entry(serio, &serio_list, node) {
if (serio->drv == drv) {
serio_disconnect_port(serio);
serio_find_driver(serio);
/* we could've deleted some ports, restart */
goto start_over;
}
}
driver_unregister(&drv->driver);
up(&serio_sem);
}
static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
{
down(&serio->drv_sem);
serio_pause_rx(serio);
serio->drv = drv;
serio_continue_rx(serio);
up(&serio->drv_sem);
}
static int serio_bus_match(struct device *dev, struct device_driver *drv)
{
struct serio *serio = to_serio_port(dev);
struct serio_driver *serio_drv = to_serio_driver(drv);
if (serio->manual_bind || serio_drv->manual_bind)
return 0;
return serio_match_port(serio_drv->id_table, serio);
}
#ifdef CONFIG_HOTPLUG
#define PUT_ENVP(fmt, val) \
do { \
envp[i++] = buffer; \
length += snprintf(buffer, buffer_size - length, fmt, val); \
if (buffer_size - length <= 0 || i >= num_envp) \
return -ENOMEM; \
length++; \
buffer += length; \
} while (0)
static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
{
struct serio *serio;
int i = 0;
int length = 0;
if (!dev)
return -ENODEV;
serio = to_serio_port(dev);
PUT_ENVP("SERIO_TYPE=%02x", serio->id.type);
PUT_ENVP("SERIO_PROTO=%02x", serio->id.proto);
PUT_ENVP("SERIO_ID=%02x", serio->id.id);
PUT_ENVP("SERIO_EXTRA=%02x", serio->id.extra);
envp[i] = NULL;
return 0;
}
#undef PUT_ENVP
#else
static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
{
return -ENODEV;
}
#endif /* CONFIG_HOTPLUG */
static int serio_resume(struct device *dev)
{
struct serio *serio = to_serio_port(dev);
if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
/*
* Driver re-probing can take a while, so better let kseriod
* deal with it.
*/
serio_rescan(serio);
}
return 0;
}
/* called from serio_driver->connect/disconnect methods under serio_sem */
int serio_open(struct serio *serio, struct serio_driver *drv)
{
serio_set_drv(serio, drv);
if (serio->open && serio->open(serio)) {
serio_set_drv(serio, NULL);
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_set_drv(serio, NULL);
}
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 && serio->registered) {
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_ERR "serio: Failed to start kseriod\n");
return -1;
}
serio_bus.dev_attrs = serio_device_attrs;
serio_bus.drv_attrs = serio_driver_attrs;
serio_bus.match = serio_bus_match;
serio_bus.hotplug = serio_hotplug;
serio_bus.resume = serio_resume;
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);