mirror of https://gitee.com/openkylin/linux.git
406 lines
9.0 KiB
C
406 lines
9.0 KiB
C
/*
|
|
* Raw serio device providing access to a raw byte stream from underlying
|
|
* serio port. Closely emulates behavior of pre-2.6 /dev/psaux device
|
|
*
|
|
* Copyright (c) 2004 Dmitry Torokhov
|
|
*
|
|
* 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/slab.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/module.h>
|
|
#include <linux/serio.h>
|
|
#include <linux/init.h>
|
|
#include <linux/major.h>
|
|
#include <linux/device.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/mutex.h>
|
|
|
|
#define DRIVER_DESC "Raw serio driver"
|
|
|
|
MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
|
|
MODULE_DESCRIPTION(DRIVER_DESC);
|
|
MODULE_LICENSE("GPL");
|
|
|
|
#define SERIO_RAW_QUEUE_LEN 64
|
|
struct serio_raw {
|
|
unsigned char queue[SERIO_RAW_QUEUE_LEN];
|
|
unsigned int tail, head;
|
|
|
|
char name[16];
|
|
unsigned int refcnt;
|
|
struct serio *serio;
|
|
struct miscdevice dev;
|
|
wait_queue_head_t wait;
|
|
struct list_head list;
|
|
struct list_head node;
|
|
};
|
|
|
|
struct serio_raw_list {
|
|
struct fasync_struct *fasync;
|
|
struct serio_raw *serio_raw;
|
|
struct list_head node;
|
|
};
|
|
|
|
static DEFINE_MUTEX(serio_raw_mutex);
|
|
static LIST_HEAD(serio_raw_list);
|
|
static unsigned int serio_raw_no;
|
|
|
|
/*********************************************************************
|
|
* Interface with userspace (file operations) *
|
|
*********************************************************************/
|
|
|
|
static int serio_raw_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct serio_raw_list *list = file->private_data;
|
|
int retval;
|
|
|
|
retval = fasync_helper(fd, file, on, &list->fasync);
|
|
return retval < 0 ? retval : 0;
|
|
}
|
|
|
|
static struct serio_raw *serio_raw_locate(int minor)
|
|
{
|
|
struct serio_raw *serio_raw;
|
|
|
|
list_for_each_entry(serio_raw, &serio_raw_list, node) {
|
|
if (serio_raw->dev.minor == minor)
|
|
return serio_raw;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int serio_raw_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct serio_raw *serio_raw;
|
|
struct serio_raw_list *list;
|
|
int retval = 0;
|
|
|
|
lock_kernel();
|
|
retval = mutex_lock_interruptible(&serio_raw_mutex);
|
|
if (retval)
|
|
goto out_bkl;
|
|
|
|
if (!(serio_raw = serio_raw_locate(iminor(inode)))) {
|
|
retval = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
if (!serio_raw->serio) {
|
|
retval = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
if (!(list = kzalloc(sizeof(struct serio_raw_list), GFP_KERNEL))) {
|
|
retval = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
list->serio_raw = serio_raw;
|
|
file->private_data = list;
|
|
|
|
serio_raw->refcnt++;
|
|
list_add_tail(&list->node, &serio_raw->list);
|
|
|
|
out:
|
|
mutex_unlock(&serio_raw_mutex);
|
|
out_bkl:
|
|
unlock_kernel();
|
|
return retval;
|
|
}
|
|
|
|
static int serio_raw_cleanup(struct serio_raw *serio_raw)
|
|
{
|
|
if (--serio_raw->refcnt == 0) {
|
|
misc_deregister(&serio_raw->dev);
|
|
list_del_init(&serio_raw->node);
|
|
kfree(serio_raw);
|
|
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int serio_raw_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct serio_raw_list *list = file->private_data;
|
|
struct serio_raw *serio_raw = list->serio_raw;
|
|
|
|
mutex_lock(&serio_raw_mutex);
|
|
|
|
serio_raw_fasync(-1, file, 0);
|
|
serio_raw_cleanup(serio_raw);
|
|
|
|
mutex_unlock(&serio_raw_mutex);
|
|
return 0;
|
|
}
|
|
|
|
static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
|
|
{
|
|
unsigned long flags;
|
|
int empty;
|
|
|
|
spin_lock_irqsave(&serio_raw->serio->lock, flags);
|
|
|
|
empty = serio_raw->head == serio_raw->tail;
|
|
if (!empty) {
|
|
*c = serio_raw->queue[serio_raw->tail];
|
|
serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&serio_raw->serio->lock, flags);
|
|
|
|
return !empty;
|
|
}
|
|
|
|
static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
|
|
{
|
|
struct serio_raw_list *list = file->private_data;
|
|
struct serio_raw *serio_raw = list->serio_raw;
|
|
char uninitialized_var(c);
|
|
ssize_t retval = 0;
|
|
|
|
if (!serio_raw->serio)
|
|
return -ENODEV;
|
|
|
|
if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK))
|
|
return -EAGAIN;
|
|
|
|
retval = wait_event_interruptible(list->serio_raw->wait,
|
|
serio_raw->head != serio_raw->tail || !serio_raw->serio);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (!serio_raw->serio)
|
|
return -ENODEV;
|
|
|
|
while (retval < count && serio_raw_fetch_byte(serio_raw, &c)) {
|
|
if (put_user(c, buffer++))
|
|
return -EFAULT;
|
|
retval++;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
|
|
{
|
|
struct serio_raw_list *list = file->private_data;
|
|
ssize_t written = 0;
|
|
int retval;
|
|
unsigned char c;
|
|
|
|
retval = mutex_lock_interruptible(&serio_raw_mutex);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (!list->serio_raw->serio) {
|
|
retval = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
if (count > 32)
|
|
count = 32;
|
|
|
|
while (count--) {
|
|
if (get_user(c, buffer++)) {
|
|
retval = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (serio_write(list->serio_raw->serio, c)) {
|
|
retval = -EIO;
|
|
goto out;
|
|
}
|
|
written++;
|
|
};
|
|
|
|
out:
|
|
mutex_unlock(&serio_raw_mutex);
|
|
return written;
|
|
}
|
|
|
|
static unsigned int serio_raw_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct serio_raw_list *list = file->private_data;
|
|
|
|
poll_wait(file, &list->serio_raw->wait, wait);
|
|
|
|
if (list->serio_raw->head != list->serio_raw->tail)
|
|
return POLLIN | POLLRDNORM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations serio_raw_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = serio_raw_open,
|
|
.release = serio_raw_release,
|
|
.read = serio_raw_read,
|
|
.write = serio_raw_write,
|
|
.poll = serio_raw_poll,
|
|
.fasync = serio_raw_fasync,
|
|
};
|
|
|
|
|
|
/*********************************************************************
|
|
* Interface with serio port *
|
|
*********************************************************************/
|
|
|
|
static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data,
|
|
unsigned int dfl)
|
|
{
|
|
struct serio_raw *serio_raw = serio_get_drvdata(serio);
|
|
struct serio_raw_list *list;
|
|
unsigned int head = serio_raw->head;
|
|
|
|
/* we are holding serio->lock here so we are prootected */
|
|
serio_raw->queue[head] = data;
|
|
head = (head + 1) % SERIO_RAW_QUEUE_LEN;
|
|
if (likely(head != serio_raw->tail)) {
|
|
serio_raw->head = head;
|
|
list_for_each_entry(list, &serio_raw->list, node)
|
|
kill_fasync(&list->fasync, SIGIO, POLL_IN);
|
|
wake_up_interruptible(&serio_raw->wait);
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int serio_raw_connect(struct serio *serio, struct serio_driver *drv)
|
|
{
|
|
struct serio_raw *serio_raw;
|
|
int err;
|
|
|
|
if (!(serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL))) {
|
|
printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
mutex_lock(&serio_raw_mutex);
|
|
|
|
snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++);
|
|
serio_raw->refcnt = 1;
|
|
serio_raw->serio = serio;
|
|
INIT_LIST_HEAD(&serio_raw->list);
|
|
init_waitqueue_head(&serio_raw->wait);
|
|
|
|
serio_set_drvdata(serio, serio_raw);
|
|
|
|
err = serio_open(serio, drv);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
list_add_tail(&serio_raw->node, &serio_raw_list);
|
|
|
|
serio_raw->dev.minor = PSMOUSE_MINOR;
|
|
serio_raw->dev.name = serio_raw->name;
|
|
serio_raw->dev.parent = &serio->dev;
|
|
serio_raw->dev.fops = &serio_raw_fops;
|
|
|
|
err = misc_register(&serio_raw->dev);
|
|
if (err) {
|
|
serio_raw->dev.minor = MISC_DYNAMIC_MINOR;
|
|
err = misc_register(&serio_raw->dev);
|
|
}
|
|
|
|
if (err) {
|
|
printk(KERN_INFO "serio_raw: failed to register raw access device for %s\n",
|
|
serio->phys);
|
|
goto out_close;
|
|
}
|
|
|
|
printk(KERN_INFO "serio_raw: raw access enabled on %s (%s, minor %d)\n",
|
|
serio->phys, serio_raw->name, serio_raw->dev.minor);
|
|
goto out;
|
|
|
|
out_close:
|
|
serio_close(serio);
|
|
list_del_init(&serio_raw->node);
|
|
out_free:
|
|
serio_set_drvdata(serio, NULL);
|
|
kfree(serio_raw);
|
|
out:
|
|
mutex_unlock(&serio_raw_mutex);
|
|
return err;
|
|
}
|
|
|
|
static int serio_raw_reconnect(struct serio *serio)
|
|
{
|
|
struct serio_raw *serio_raw = serio_get_drvdata(serio);
|
|
struct serio_driver *drv = serio->drv;
|
|
|
|
if (!drv || !serio_raw) {
|
|
printk(KERN_DEBUG "serio_raw: reconnect request, but serio is disconnected, ignoring...\n");
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Nothing needs to be done here, we just need this method to
|
|
* keep the same device.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
static void serio_raw_disconnect(struct serio *serio)
|
|
{
|
|
struct serio_raw *serio_raw;
|
|
|
|
mutex_lock(&serio_raw_mutex);
|
|
|
|
serio_raw = serio_get_drvdata(serio);
|
|
|
|
serio_close(serio);
|
|
serio_set_drvdata(serio, NULL);
|
|
|
|
serio_raw->serio = NULL;
|
|
if (!serio_raw_cleanup(serio_raw))
|
|
wake_up_interruptible(&serio_raw->wait);
|
|
|
|
mutex_unlock(&serio_raw_mutex);
|
|
}
|
|
|
|
static struct serio_device_id serio_raw_serio_ids[] = {
|
|
{
|
|
.type = SERIO_8042,
|
|
.proto = SERIO_ANY,
|
|
.id = SERIO_ANY,
|
|
.extra = SERIO_ANY,
|
|
},
|
|
{ 0 }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids);
|
|
|
|
static struct serio_driver serio_raw_drv = {
|
|
.driver = {
|
|
.name = "serio_raw",
|
|
},
|
|
.description = DRIVER_DESC,
|
|
.id_table = serio_raw_serio_ids,
|
|
.interrupt = serio_raw_interrupt,
|
|
.connect = serio_raw_connect,
|
|
.reconnect = serio_raw_reconnect,
|
|
.disconnect = serio_raw_disconnect,
|
|
.manual_bind = 1,
|
|
};
|
|
|
|
static int __init serio_raw_init(void)
|
|
{
|
|
return serio_register_driver(&serio_raw_drv);
|
|
}
|
|
|
|
static void __exit serio_raw_exit(void)
|
|
{
|
|
serio_unregister_driver(&serio_raw_drv);
|
|
}
|
|
|
|
module_init(serio_raw_init);
|
|
module_exit(serio_raw_exit);
|