ppdev.c

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		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 ((int *)arg, &mode, sizeof (mode))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPSETPHASE:
	    {
		int phase;
		if (copy_from_user (&phase, (int *) arg, 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 ((int *)arg, &phase, sizeof (phase))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPGETMODES:
	    {
		unsigned int modes;

		port = parport_find_number (minor);
		if (!port)
			return -ENODEV;

		modes = port->modes;
		if (copy_to_user ((unsigned int *)arg, &modes, sizeof (modes))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPSETFLAGS:
	    {
		int uflags;

		if (copy_from_user (&uflags, (int *)arg, 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 ((int *)arg, &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) {
		printk (KERN_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 ((unsigned char *) arg, &reg, sizeof (reg)))
			return -EFAULT;
		return 0;
	case PPRDATA:
		reg = parport_read_data (port);
		if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
			return -EFAULT;
		return 0;
	case PPRCONTROL:
		reg = parport_read_control (port);
		if (copy_to_user ((unsigned char *) arg, &reg, 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 (&reg, (unsigned char *) arg, sizeof (reg)))
			return -EFAULT;
		parport_write_control (port, reg);
		return 0;

	case PPWDATA:
		if (copy_from_user (&reg, (unsigned char *) arg, sizeof (reg)))
			return -EFAULT;
		parport_write_data (port, reg);
		return 0;

	case PPFCONTROL:
		if (copy_from_user (&mask, (unsigned char *) arg,
				    sizeof (mask)))
			return -EFAULT;
		if (copy_from_user (&reg, 1 + (unsigned char *) arg,
				    sizeof (reg)))
			return -EFAULT;
		parport_frob_control (port, mask, reg);
		return 0;

	case PPDATADIR:
		if (copy_from_user (&mode, (int *) arg, 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, (int *) arg, 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 (&reg, (unsigned char *) arg,
				    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 ((int *) arg, &ret, sizeof (ret)))
			return -EFAULT;
		atomic_sub (ret, &pp->irqc);
		return 0;

	case PPSETTIME:
		if (copy_from_user (&par_timeout, (struct timeval *)arg,
				    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;
		par_timeout.tv_sec = to_jiffies / HZ;
		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
		if (copy_to_user ((struct timeval *)arg, &par_timeout,
				  sizeof(struct timeval))) {
			return -EFAULT;
		}
		return 0;

	default:
		printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
			cmd);
		return -EINVAL;
	}

	/* Keep the compiler happy */
	return 0;
}

static int pp_open (struct inode * inode, struct file * file)
{
	unsigned int minor = MINOR (inode->i_rdev);
	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 = MINOR (inode->i_rdev);
	struct pp_struct *pp = file->private_data;
	int compat_negot;

	lock_kernel();
	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 compatability 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);
		printk (KERN_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) {
			printk (KERN_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;
		printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
			minor);
	}
	unlock_kernel();

	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 file_operations pp_fops = {
	owner:		THIS_MODULE,
	llseek:		no_llseek,
	read:		pp_read,
	write:		pp_write,
	poll:		pp_poll,
	ioctl:		pp_ioctl,
	open:		pp_open,
	release:	pp_release,
};

static devfs_handle_t devfs_handle;

static int __init ppdev_init (void)
{
	if (devfs_register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
			PP_MAJOR);
		return -EIO;
	}
	devfs_handle = devfs_mk_dir (NULL, "parports", NULL);
	devfs_register_series (devfs_handle, "%u", PARPORT_MAX,
			       DEVFS_FL_DEFAULT, PP_MAJOR, 0,
			       S_IFCHR | S_IRUGO | S_IWUGO,
			       &pp_fops, NULL);

	printk (KERN_INFO PP_VERSION "\n");
	return 0;
}

static void __exit ppdev_cleanup (void)
{
	/* Clean up all parport stuff */
	devfs_unregister (devfs_handle);
	devfs_unregister_chrdev (PP_MAJOR, CHRDEV);
}

module_init(ppdev_init);
module_exit(ppdev_cleanup);

MODULE_LICENSE("GPL");

EXPORT_NO_SYMBOLS;