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// SPDX-License-Identifier: GPL-2.0-or-later/* * 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> * * 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/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;	} 	index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);	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);	parport_put_port(port); 	if (!pdev) {		pr_warn("%s: failed to register device!\n", name);		rc = -ENXIO;		ida_simple_remove(&ida_index, index);		goto err;	} 	pp->pdev = pdev;	pp->index = index;	dev_dbg(&pdev->dev, "registered pardevice\n");err:	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, long tv_sec, int tv_usec){	long to_jiffies; 	if ((tv_sec < 0) || (tv_usec < 0))		return -EINVAL; 	to_jiffies = usecs_to_jiffies(tv_usec);	to_jiffies += tv_sec * HZ;	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;	    }

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