- 根目录:
- drivers
- char
- ppdev.c
/*
* linux/drivers/char/ppdev.c
*
* This is the code behind /dev/parport* -- it allows a user-space
* application to use the parport subsystem.
*
* Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
*
* 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.
*
* A /dev/parportx device node represents an arbitrary device
* on port 'x'. The following operations are possible:
*
* open do nothing, set up default IEEE 1284 protocol to be COMPAT
* close release port and unregister device (if necessary)
* ioctl
* EXCL register device exclusively (may fail)
* CLAIM (register device first time) parport_claim_or_block
* RELEASE parport_release
* SETMODE set the IEEE 1284 protocol to use for read/write
* SETPHASE set the IEEE 1284 phase of a particular mode. Not to be
* confused with ioctl(fd, SETPHASER, &stun). ;-)
* DATADIR data_forward / data_reverse
* WDATA write_data
* RDATA read_data
* WCONTROL write_control
* RCONTROL read_control
* FCONTROL frob_control
* RSTATUS read_status
* NEGOT parport_negotiate
* YIELD parport_yield_blocking
* WCTLONIRQ on interrupt, set control lines
* CLRIRQ clear (and return) interrupt count
* SETTIME sets device timeout (struct timeval)
* GETTIME gets device timeout (struct timeval)
* GETMODES gets hardware supported modes (unsigned int)
* GETMODE gets the current IEEE1284 mode
* GETPHASE gets the current IEEE1284 phase
* GETFLAGS gets current (user-visible) flags
* SETFLAGS sets current (user-visible) flags
* read/write read or write in current IEEE 1284 protocol
* select wait for interrupt (in readfds)
*
* Changes:
* Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
*
* Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
* - On error, copy_from_user and copy_to_user do not return -EFAULT,
* They return the positive number of bytes *not* copied due to address
* space errors.
*
* Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
* Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/ioctl.h>
#include <linux/parport.h>
#include <linux/ctype.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/ppdev.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#define PP_VERSION "ppdev: user-space parallel port driver"
#define CHRDEV "ppdev"
struct pp_struct {
struct pardevice * pdev;
wait_queue_head_t irq_wait;
atomic_t irqc;
unsigned int flags;
int irqresponse;
unsigned char irqctl;
struct ieee1284_info state;
struct ieee1284_info saved_state;
long default_inactivity;
};
/* pp_struct.flags bitfields */
#define PP_CLAIMED (1<<0)
#define PP_EXCL (1<<1)
/* Other constants */
#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
#define PP_BUFFER_SIZE 1024
#define PARDEVICE_MAX 8
/* ROUND_UP macro from fs/select.c */
#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
static DEFINE_MUTEX(pp_do_mutex);
static inline void pp_enable_irq (struct pp_struct *pp)
{
struct parport *port = pp->pdev->port;
port->ops->enable_irq (port);
}
static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
loff_t * ppos)
{
unsigned int minor = iminor(file_inode(file));
struct pp_struct *pp = file->private_data;
char * kbuffer;
ssize_t bytes_read = 0;
struct parport *pport;
int mode;
if (!(pp->flags & PP_CLAIMED)) {
/* Don't have the port claimed */
pr_debug(CHRDEV "%x: claim the port first\n", minor);
return -EINVAL;
}
/* Trivial case. */
if (count == 0)
return 0;
kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
if (!kbuffer) {
return -ENOMEM;
}
pport = pp->pdev->port;
mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
parport_set_timeout (pp->pdev,
(file->f_flags & O_NONBLOCK) ?
PARPORT_INACTIVITY_O_NONBLOCK :
pp->default_inactivity);
while (bytes_read == 0) {
ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
if (mode == IEEE1284_MODE_EPP) {
/* various specials for EPP mode */
int flags = 0;
size_t (*fn)(struct parport *, void *, size_t, int);
if (pp->flags & PP_W91284PIC) {
flags |= PARPORT_W91284PIC;
}
if (pp->flags & PP_FASTREAD) {
flags |= PARPORT_EPP_FAST;
}
if (pport->ieee1284.mode & IEEE1284_ADDR) {
fn = pport->ops->epp_read_addr;
} else {
fn = pport->ops->epp_read_data;
}
bytes_read = (*fn)(pport, kbuffer, need, flags);
} else {
bytes_read = parport_read (pport, kbuffer, need);
}
if (bytes_read != 0)
break;
if (file->f_flags & O_NONBLOCK) {
bytes_read = -EAGAIN;
break;
}
if (signal_pending (current)) {
bytes_read = -ERESTARTSYS;
break;
}
cond_resched();
}
parport_set_timeout (pp->pdev, pp->default_inactivity);
if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
bytes_read = -EFAULT;
kfree (kbuffer);
pp_enable_irq (pp);
return bytes_read;
}
static ssize_t pp_write (struct file * file, const char __user * buf,
size_t count, loff_t * ppos)
{
unsigned int minor = iminor(file_inode(file));
struct pp_struct *pp = file->private_data;
char * kbuffer;
ssize_t bytes_written = 0;
ssize_t wrote;
int mode;
struct parport *pport;
if (!(pp->flags & PP_CLAIMED)) {
/* Don't have the port claimed */
pr_debug(CHRDEV "%x: claim the port first\n", minor);
return -EINVAL;
}
kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
if (!kbuffer) {
return -ENOMEM;
}
pport = pp->pdev->port;
mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
parport_set_timeout (pp->pdev,
(file->f_flags & O_NONBLOCK) ?
PARPORT_INACTIVITY_O_NONBLOCK :
pp->default_inactivity);
while (bytes_written < count) {
ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
if (copy_from_user (kbuffer, buf + bytes_written, n)) {
bytes_written = -EFAULT;
break;
}
if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
/* do a fast EPP write */
if (pport->ieee1284.mode & IEEE1284_ADDR) {
wrote = pport->ops->epp_write_addr (pport,
kbuffer, n, PARPORT_EPP_FAST);
} else {
wrote = pport->ops->epp_write_data (pport,
kbuffer, n, PARPORT_EPP_FAST);
}
} else {
wrote = parport_write (pp->pdev->port, kbuffer, n);
}
if (wrote <= 0) {
if (!bytes_written) {
bytes_written = wrote;
}
break;
}
bytes_written += wrote;
if (file->f_flags & O_NONBLOCK) {
if (!bytes_written)
bytes_written = -EAGAIN;
break;
}
if (signal_pending (current))
break;
cond_resched();
}
parport_set_timeout (pp->pdev, pp->default_inactivity);
kfree (kbuffer);
pp_enable_irq (pp);
return bytes_written;
}
static void pp_irq (void *private)
{
struct pp_struct *pp = private;
if (pp->irqresponse) {
parport_write_control (pp->pdev->port, pp->irqctl);
pp->irqresponse = 0;
}
atomic_inc (&pp->irqc);
wake_up_interruptible (&pp->irq_wait);
}
static int register_device (int minor, struct pp_struct *pp)
{
struct parport *port;
struct pardevice * pdev = NULL;
char *name;
int fl;
name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
if (name == NULL)
return -ENOMEM;
port = parport_find_number (minor);
if (!port) {
printk (KERN_WARNING "%s: no associated port!\n", name);
kfree (name);
return -ENXIO;
}
fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
pdev = parport_register_device (port, name, NULL,
NULL, pp_irq, fl, pp);
parport_put_port (port);
if (!pdev) {
printk (KERN_WARNING "%s: failed to register device!\n", name);
kfree (name);
return -ENXIO;
}
pp->pdev = pdev;
pr_debug("%s: registered pardevice\n", name);
return 0;
}
static enum ieee1284_phase init_phase (int mode)
{
switch (mode & ~(IEEE1284_DEVICEID
| IEEE1284_ADDR)) {
case IEEE1284_MODE_NIBBLE:
case IEEE1284_MODE_BYTE:
return IEEE1284_PH_REV_IDLE;
}
return IEEE1284_PH_FWD_IDLE;
}
static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int minor = iminor(file_inode(file));
struct pp_struct *pp = file->private_data;
struct parport * port;
void __user *argp = (void __user *)arg;
/* First handle the cases that don't take arguments. */
switch (cmd) {
case PPCLAIM:
{
struct ieee1284_info *info;
int ret;
if (pp->flags & PP_CLAIMED) {
pr_debug(CHRDEV "%x: you've already got it!\n", minor);
return -EINVAL;
}
/* Deferred device registration. */
if (!pp->pdev) {
int err = register_device (minor, pp);
if (err) {
return err;
}
}
ret = parport_claim_or_block (pp->pdev);
if (ret < 0)
return ret;
pp->flags |= PP_CLAIMED;
/* For interrupt-reporting to work, we need to be
* informed of each interrupt. */
pp_enable_irq (pp);
/* We may need to fix up the state machine. */
info = &pp->pdev->port->ieee1284;
pp->saved_state.mode = info->mode;
pp->saved_state.phase = info->phase;
info->mode = pp->state.mode;
info->phase = pp->state.phase;
pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
parport_set_timeout (pp->pdev, pp->default_inactivity);
return 0;
}
case PPEXCL:
if (pp->pdev) {
pr_debug(CHRDEV "%x: too late for PPEXCL; "
"already registered\n", minor);
if (pp->flags & PP_EXCL)
/* But it's not really an error. */
return 0;
/* There's no chance of making the driver happy. */
return -EINVAL;
}
/* Just remember to register the device exclusively
* when we finally do the registration. */
pp->flags |= PP_EXCL;
return 0;
case PPSETMODE:
{
int mode;
if (copy_from_user (&mode, argp, sizeof (mode)))
return -EFAULT;
/* FIXME: validate mode */
pp->state.mode = mode;
pp->state.phase = init_phase (mode);
if (pp->flags & PP_CLAIMED) {
pp->pdev->port->ieee1284.mode = mode;
pp->pdev->port->ieee1284.phase = pp->state.phase;
}
return 0;
}
case PPGETMODE:
{
int mode;
if (pp->flags & PP_CLAIMED) {
mode = pp->pdev->port->ieee1284.mode;
} else {
mode = pp->state.mode;
}
if (copy_to_user (argp, &mode, sizeof (mode))) {
return -EFAULT;
}
return 0;
}
case PPSETPHASE:
{
int phase;
if (copy_from_user (&phase, argp, sizeof (phase))) {
return -EFAULT;
}
/* FIXME: validate phase */
pp->state.phase = phase;
if (pp->flags & PP_CLAIMED) {
pp->pdev->port->ieee1284.phase = phase;
}
return 0;
}
case PPGETPHASE:
{
int phase;
if (pp->flags & PP_CLAIMED) {
phase = pp->pdev->port->ieee1284.phase;
} else {
phase = pp->state.phase;
}
if (copy_to_user (argp, &phase, sizeof (phase))) {
return -EFAULT;
}
return 0;
}
case PPGETMODES:
{
unsigned int modes;
port = parport_find_number (minor);
if (!port)
return -ENODEV;
modes = port->modes;
parport_put_port(port);
if (copy_to_user (argp, &modes, sizeof (modes))) {
return -EFAULT;
}
return 0;
}
case PPSETFLAGS:
{
int uflags;
if (copy_from_user (&uflags, argp, sizeof (uflags))) {
return -EFAULT;
}
pp->flags &= ~PP_FLAGMASK;
pp->flags |= (uflags & PP_FLAGMASK);
return 0;
}
case PPGETFLAGS:
{
int uflags;
uflags = pp->flags & PP_FLAGMASK;
if (copy_to_user (argp, &uflags, sizeof (uflags))) {
return -EFAULT;
}
return 0;
}
} /* end switch() */
/* Everything else requires the port to be claimed, so check
* that now. */
if ((pp->flags & PP_CLAIMED) == 0) {
pr_debug(CHRDEV "%x: claim the port first\n", minor);
return -EINVAL;
}
port = pp->pdev->port;
switch (cmd) {
struct ieee1284_info *info;
unsigned char reg;
unsigned char mask;
int mode;
int ret;
struct timeval par_timeout;
long to_jiffies;
case PPRSTATUS:
reg = parport_read_status (port);
if (copy_to_user (argp, ®, sizeof (reg)))
return -EFAULT;
return 0;
case PPRDATA:
reg = parport_read_data (port);
if (copy_to_user (argp, ®, sizeof (reg)))
return -EFAULT;
return 0;
case PPRCONTROL:
reg = parport_read_control (port);
if (copy_to_user (argp, ®, sizeof (reg)))
return -EFAULT;
return 0;
case PPYIELD:
parport_yield_blocking (pp->pdev);
return 0;
case PPRELEASE:
/* Save the state machine's state. */
info = &pp->pdev->port->ieee1284;
pp->state.mode = info->mode;
pp->state.phase = info->phase;
info->mode = pp->saved_state.mode;
info->phase = pp->saved_state.phase;
parport_release (pp->pdev);
pp->flags &= ~PP_CLAIMED;
return 0;
case PPWCONTROL:
if (copy_from_user (®, argp, sizeof (reg)))
return -EFAULT;
parport_write_control (port, reg);
return 0;
case PPWDATA:
if (copy_from_user (®, argp, sizeof (reg)))
return -EFAULT;
parport_write_data (port, reg);
return 0;
case PPFCONTROL:
if (copy_from_user (&mask, argp,
sizeof (mask)))
return -EFAULT;
if (copy_from_user (®, 1 + (unsigned char __user *) arg,
sizeof (reg)))
return -EFAULT;
parport_frob_control (port, mask, reg);
return 0;
case PPDATADIR:
if (copy_from_user (&mode, argp, sizeof (mode)))
return -EFAULT;
if (mode)
port->ops->data_reverse (port);
else
port->ops->data_forward (port);
return 0;
case PPNEGOT:
if (copy_from_user (&mode, argp, sizeof (mode)))
return -EFAULT;
switch ((ret = parport_negotiate (port, mode))) {
case 0: break;
case -1: /* handshake failed, peripheral not IEEE 1284 */
ret = -EIO;
break;
case 1: /* handshake succeeded, peripheral rejected mode */
ret = -ENXIO;
break;
}
pp_enable_irq (pp);
return ret;
case PPWCTLONIRQ:
if (copy_from_user (®, argp, sizeof (reg)))
return -EFAULT;
/* Remember what to set the control lines to, for next
* time we get an interrupt. */
pp->irqctl = reg;
pp->irqresponse = 1;
return 0;
case PPCLRIRQ:
ret = atomic_read (&pp->irqc);
if (copy_to_user (argp, &ret, sizeof (ret)))
return -EFAULT;
atomic_sub (ret, &pp->irqc);
return 0;
case PPSETTIME:
if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
return -EFAULT;
}
/* Convert to jiffies, place in pp->pdev->timeout */
if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
return -EINVAL;
}
to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
to_jiffies += par_timeout.tv_sec * (long)HZ;
if (to_jiffies <= 0) {
return -EINVAL;
}
pp->pdev->timeout = to_jiffies;
return 0;
case PPGETTIME:
to_jiffies = pp->pdev->timeout;
memset(&par_timeout, 0, sizeof(par_timeout));
par_timeout.tv_sec = to_jiffies / HZ;
par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
return -EFAULT;
return 0;
default:
pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
return -EINVAL;
}
/* Keep the compiler happy */
return 0;
}
static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret;
mutex_lock(&pp_do_mutex);
ret = pp_do_ioctl(file, cmd, arg);
mutex_unlock(&pp_do_mutex);
return ret;
}
static int pp_open (struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct pp_struct *pp;
if (minor >= PARPORT_MAX)
return -ENXIO;
pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
if (!pp)
return -ENOMEM;
pp->state.mode = IEEE1284_MODE_COMPAT;
pp->state.phase = init_phase (pp->state.mode);
pp->flags = 0;
pp->irqresponse = 0;
atomic_set (&pp->irqc, 0);
init_waitqueue_head (&pp->irq_wait);
/* Defer the actual device registration until the first claim.
* That way, we know whether or not the driver wants to have
* exclusive access to the port (PPEXCL).
*/
pp->pdev = NULL;
file->private_data = pp;
return 0;
}
static int pp_release (struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct pp_struct *pp = file->private_data;
int compat_negot;
compat_negot = 0;
if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
(pp->state.mode != IEEE1284_MODE_COMPAT)) {
struct ieee1284_info *info;
/* parport released, but not in compatibility mode */
parport_claim_or_block (pp->pdev);
pp->flags |= PP_CLAIMED;
info = &pp->pdev->port->ieee1284;
pp->saved_state.mode = info->mode;
pp->saved_state.phase = info->phase;
info->mode = pp->state.mode;
info->phase = pp->state.phase;
compat_negot = 1;
} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
(pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
compat_negot = 2;
}
if (compat_negot) {
parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
pr_debug(CHRDEV "%x: negotiated back to compatibility "
"mode because user-space forgot\n", minor);
}
if (pp->flags & PP_CLAIMED) {
struct ieee1284_info *info;
info = &pp->pdev->port->ieee1284;
pp->state.mode = info->mode;
pp->state.phase = info->phase;
info->mode = pp->saved_state.mode;
info->phase = pp->saved_state.phase;
parport_release (pp->pdev);
if (compat_negot != 1) {
pr_debug(CHRDEV "%x: released pardevice "
"because user-space forgot\n", minor);
}
}
if (pp->pdev) {
const char *name = pp->pdev->name;
parport_unregister_device (pp->pdev);
kfree (name);
pp->pdev = NULL;
pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
}
kfree (pp);
return 0;
}
/* No kernel lock held - fine */
static unsigned int pp_poll (struct file * file, poll_table * wait)
{
struct pp_struct *pp = file->private_data;
unsigned int mask = 0;
poll_wait (file, &pp->irq_wait, wait);
if (atomic_read (&pp->irqc))
mask |= POLLIN | POLLRDNORM;
return mask;
}
static struct class *ppdev_class;
static const struct file_operations pp_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = pp_read,
.write = pp_write,
.poll = pp_poll,
.unlocked_ioctl = pp_ioctl,
.open = pp_open,
.release = pp_release,
};
static void pp_attach(struct parport *port)
{
device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
NULL, "parport%d", port->number);
}
static void pp_detach(struct parport *port)
{
device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
}
static struct parport_driver pp_driver = {
.name = CHRDEV,
.attach = pp_attach,
.detach = pp_detach,
};
static int __init ppdev_init (void)
{
int err = 0;
if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
PP_MAJOR);
return -EIO;
}
ppdev_class = class_create(THIS_MODULE, CHRDEV);
if (IS_ERR(ppdev_class)) {
err = PTR_ERR(ppdev_class);
goto out_chrdev;
}
err = parport_register_driver(&pp_driver);
if (err < 0) {
printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
goto out_class;
}
printk (KERN_INFO PP_VERSION "\n");
goto out;
out_class:
class_destroy(ppdev_class);
out_chrdev:
unregister_chrdev(PP_MAJOR, CHRDEV);
out:
return err;
}
static void __exit ppdev_cleanup (void)
{
/* Clean up all parport stuff */
parport_unregister_driver(&pp_driver);
class_destroy(ppdev_class);
unregister_chrdev (PP_MAJOR, CHRDEV);
}
module_init(ppdev_init);
module_exit(ppdev_cleanup);
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);