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#include <linux/module.h>#include <linux/init.h>#include <linux/sched/signal.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>#include <linux/compat.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; int index;};
/* should we use PARDEVICE_MAX here? */static struct device *devices[PARPORT_MAX];
static DEFINE_IDA(ida_index);
/* 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
static DEFINE_MUTEX(pp_do_mutex);
/* define fixed sized ioctl cmd for y2038 migration */#define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])#define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])#define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])#define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
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; struct pardev_cb ppdev_cb; int rc = 0, index;
name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor); if (name == NULL) return -ENOMEM;
port = parport_find_number(minor); if (!port) { pr_warn("%s: no associated port!\n", name); rc = -ENXIO; goto err_free_name; }
index = ida_alloc(&ida_index, GFP_KERNEL); if (index < 0) { pr_warn("%s: failed to get index!\n", name); rc = index; goto err_put_port; }
memset(&ppdev_cb, 0, sizeof(ppdev_cb)); ppdev_cb.irq_func = pp_irq; ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0; ppdev_cb.private = pp; pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
if (!pdev) { pr_warn("%s: failed to register device!\n", name); rc = -ENXIO; ida_free(&ida_index, index); goto err_put_port; }
pp->pdev = pdev; pp->index = index; dev_dbg(&pdev->dev, "registered pardevice\n");err_put_port: parport_put_port(port);err_free_name: kfree(name); return rc;}
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_set_timeout(struct pardevice *pdev, s64 tv_sec, s64 tv_usec){ struct timespec64 ts; long to_jiffies;
if (tv_sec < 0 || tv_usec < 0 || tv_usec >= USEC_PER_SEC) return -EINVAL;
ts.tv_sec = tv_sec; ts.tv_nsec = tv_usec * NSEC_PER_USEC; to_jiffies = timespec64_to_jiffies(&ts); if (to_jiffies <= 0) return -EINVAL;
pdev->timeout = to_jiffies; return 0;}
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; struct ieee1284_info *info; unsigned char reg; unsigned char mask; int mode; s32 time32[2]; s64 time64[2]; struct timespec64 ts; int ret;
/* First handle the cases that don't take arguments. */ switch (cmd) { case PPCLAIM: { if (pp->flags & PP_CLAIMED) { dev_dbg(&pp->pdev->dev, "you've already got it!\n"); 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) { dev_dbg(&pp->pdev->dev, "too late for PPEXCL; already registered\n"); 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) { 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 PPSETTIME32: if (copy_from_user(time32, argp, sizeof(time32))) return -EFAULT;
if ((time32[0] < 0) || (time32[1] < 0)) return -EINVAL;
return pp_set_timeout(pp->pdev, time32[0], time32[1]);
case PPSETTIME64: if (copy_from_user(time64, argp, sizeof(time64))) return -EFAULT;
if ((time64[0] < 0) || (time64[1] < 0)) return -EINVAL;
if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall()) time64[1] >>= 32;
return pp_set_timeout(pp->pdev, time64[0], time64[1]);
case PPGETTIME32: jiffies_to_timespec64(pp->pdev->timeout, &ts); time32[0] = ts.tv_sec; time32[1] = ts.tv_nsec / NSEC_PER_USEC;
if (copy_to_user(argp, time32, sizeof(time32))) return -EFAULT;
return 0;
case PPGETTIME64: jiffies_to_timespec64(pp->pdev->timeout, &ts); time64[0] = ts.tv_sec; time64[1] = ts.tv_nsec / NSEC_PER_USEC;
if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall()) time64[1] <<= 32;
if (copy_to_user(argp, time64, sizeof(time64))) return -EFAULT;
return 0;
default: dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", 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_obj(struct pp_struct); 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); dev_dbg(&pp->pdev->dev, "negotiated back to compatibility mode because user-space forgot\n"); }
if ((pp->flags & PP_CLAIMED) && pp->pdev) { 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) { parport_unregister_device(pp->pdev); ida_free(&ida_index, pp->index); pp->pdev = NULL; pr_debug(CHRDEV "%x: unregistered pardevice\n", minor); }
kfree(pp);
return 0;}
/* No kernel lock held - fine */static __poll_t pp_poll(struct file *file, poll_table *wait){ struct pp_struct *pp = file->private_data; __poll_t mask = 0;
poll_wait(file, &pp->irq_wait, wait); if (atomic_read(&pp->irqc)) mask |= EPOLLIN | EPOLLRDNORM;
return mask;}
static const struct class ppdev_class = { .name = CHRDEV,};
static const struct file_operations pp_fops = { .owner = THIS_MODULE, .read = pp_read, .write = pp_write, .poll = pp_poll, .unlocked_ioctl = pp_ioctl, .compat_ioctl = compat_ptr_ioctl, .open = pp_open, .release = pp_release,};
static void pp_attach(struct parport *port){ struct device *ret;
if (devices[port->number]) return;
ret = device_create(&ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number), NULL, "parport%d", port->number); if (IS_ERR(ret)) { pr_err("Failed to create device parport%d\n", port->number); return; } devices[port->number] = ret;}
static void pp_detach(struct parport *port){ if (!devices[port->number]) return;
device_destroy(&ppdev_class, MKDEV(PP_MAJOR, port->number)); devices[port->number] = NULL;}
static int pp_probe(struct pardevice *par_dev){ struct device_driver *drv = par_dev->dev.driver; int len = strlen(drv->name);
if (strncmp(par_dev->name, drv->name, len)) return -ENODEV;
return 0;}
static struct parport_driver pp_driver = { .name = CHRDEV, .probe = pp_probe, .match_port = pp_attach, .detach = pp_detach,};
static int __init ppdev_init(void){ int err = 0;
if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) { pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR); return -EIO; } err = class_register(&ppdev_class); if (err) goto out_chrdev;
err = parport_register_driver(&pp_driver); if (err < 0) { pr_warn(CHRDEV ": unable to register with parport\n"); goto out_class; }
pr_info(PP_VERSION "\n"); goto out;
out_class: class_unregister(&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_unregister(&ppdev_class); unregister_chrdev(PP_MAJOR, CHRDEV);}
module_init(ppdev_init);module_exit(ppdev_cleanup);
MODULE_DESCRIPTION("Support for user-space parallel port device drivers");MODULE_LICENSE("GPL");MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);