[mirror_ubuntu-artful-kernel.git] / drivers / parport / daisy.c

/*
 * IEEE 1284.3 Parallel port daisy chain and multiplexor code
 * 
 * Copyright (C) 1999, 2000  Tim Waugh <tim@cyberelk.demon.co.uk>
 *
 * 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.
 *
 * ??-12-1998: Initial implementation.
 * 31-01-1999: Make port-cloning transparent.
 * 13-02-1999: Move DeviceID technique from parport_probe.
 * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too.
 * 22-02-2000: Count devices that are actually detected.
 *
 * Any part of this program may be used in documents licensed under
 * the GNU Free Documentation License, Version 1.1 or any later version
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/parport.h>
#include <linux/delay.h>
#include <linux/sched.h>

#include <asm/current.h>
#include <asm/uaccess.h>

#undef DEBUG

#ifdef DEBUG
#define DPRINTK(stuff...) printk(stuff)
#else
#define DPRINTK(stuff...)
#endif

static struct daisydev {
	struct daisydev *next;
	struct parport *port;
	int daisy;
	int devnum;
} *topology = NULL;
static DEFINE_SPINLOCK(topology_lock);

static int numdevs = 0;

/* Forward-declaration of lower-level functions. */
static int mux_present(struct parport *port);
static int num_mux_ports(struct parport *port);
static int select_port(struct parport *port);
static int assign_addrs(struct parport *port);

/* Add a device to the discovered topology. */
static void add_dev(int devnum, struct parport *port, int daisy)
{
	struct daisydev *newdev, **p;
	newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL);
	if (newdev) {
		newdev->port = port;
		newdev->daisy = daisy;
		newdev->devnum = devnum;
		spin_lock(&topology_lock);
		for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next)
			;
		newdev->next = *p;
		*p = newdev;
		spin_unlock(&topology_lock);
	}
}

/* Clone a parport (actually, make an alias). */
static struct parport *clone_parport(struct parport *real, int muxport)
{
	struct parport *extra = parport_register_port(real->base,
						       real->irq,
						       real->dma,
						       real->ops);
	if (extra) {
		extra->portnum = real->portnum;
		extra->physport = real;
		extra->muxport = muxport;
		real->slaves[muxport-1] = extra;
	}

	return extra;
}

/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
 * Return value is number of devices actually detected. */
int parport_daisy_init(struct parport *port)
{
	int detected = 0;
	char *deviceid;
	static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
	int num_ports;
	int i;
	int last_try = 0;

again:
	/* Because this is called before any other devices exist,
	 * we don't have to claim exclusive access.  */

	/* If mux present on normal port, need to create new
	 * parports for each extra port. */
	if (port->muxport < 0 && mux_present(port) &&
	    /* don't be fooled: a mux must have 2 or 4 ports. */
	    ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {
		/* Leave original as port zero. */
		port->muxport = 0;
		printk(KERN_INFO
			"%s: 1st (default) port of %d-way multiplexor\n",
			port->name, num_ports);
		for (i = 1; i < num_ports; i++) {
			/* Clone the port. */
			struct parport *extra = clone_parport(port, i);
			if (!extra) {
				if (signal_pending(current))
					break;

				schedule();
				continue;
			}

			printk(KERN_INFO
				"%s: %d%s port of %d-way multiplexor on %s\n",
				extra->name, i + 1, th[i + 1], num_ports,
				port->name);

			/* Analyse that port too.  We won't recurse
			   forever because of the 'port->muxport < 0'
			   test above. */
			parport_daisy_init(extra);
		}
	}

	if (port->muxport >= 0)
		select_port(port);

	parport_daisy_deselect_all(port);
	detected += assign_addrs(port);

	/* Count the potential legacy device at the end. */
	add_dev(numdevs++, port, -1);

	/* Find out the legacy device's IEEE 1284 device ID. */
	deviceid = kmalloc(1024, GFP_KERNEL);
	if (deviceid) {
		if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
			detected++;

		kfree(deviceid);
	}

	if (!detected && !last_try) {
		/* No devices were detected.  Perhaps they are in some
                   funny state; let's try to reset them and see if
                   they wake up. */
		parport_daisy_fini(port);
		parport_write_control(port, PARPORT_CONTROL_SELECT);
		udelay(50);
		parport_write_control(port,
				       PARPORT_CONTROL_SELECT |
				       PARPORT_CONTROL_INIT);
		udelay(50);
		last_try = 1;
		goto again;
	}

	return detected;
}

/* Forget about devices on a physical port. */
void parport_daisy_fini(struct parport *port)
{
	struct daisydev **p;

	spin_lock(&topology_lock);
	p = &topology;
	while (*p) {
		struct daisydev *dev = *p;
		if (dev->port != port) {
			p = &dev->next;
			continue;
		}
		*p = dev->next;
		kfree(dev);
	}

	/* Gaps in the numbering could be handled better.  How should
           someone enumerate through all IEEE1284.3 devices in the
           topology?. */
	if (!topology) numdevs = 0;
	spin_unlock(&topology_lock);
	return;
}

/**
 *	parport_open - find a device by canonical device number
 *	@devnum: canonical device number
 *	@name: name to associate with the device
 *	@pf: preemption callback
 *	@kf: kick callback
 *	@irqf: interrupt handler
 *	@flags: registration flags
 *	@handle: driver data
 *
 *	This function is similar to parport_register_device(), except
 *	that it locates a device by its number rather than by the port
 *	it is attached to.
 *
 *	All parameters except for @devnum are the same as for
 *	parport_register_device().  The return value is the same as
 *	for parport_register_device().
 **/

struct pardevice *parport_open(int devnum, const char *name,
				int (*pf) (void *), void (*kf) (void *),
				void (*irqf) (int, void *),
				int flags, void *handle)
{
	struct daisydev *p = topology;
	struct parport *port;
	struct pardevice *dev;
	int daisy;

	spin_lock(&topology_lock);
	while (p && p->devnum != devnum)
		p = p->next;

	if (!p) {
		spin_unlock(&topology_lock);
		return NULL;
	}

	daisy = p->daisy;
	port = parport_get_port(p->port);
	spin_unlock(&topology_lock);

	dev = parport_register_device(port, name, pf, kf,
				       irqf, flags, handle);
	parport_put_port(port);
	if (!dev)
		return NULL;

	dev->daisy = daisy;

	/* Check that there really is a device to select. */
	if (daisy >= 0) {
		int selected;
		parport_claim_or_block(dev);
		selected = port->daisy;
		parport_release(dev);

		if (selected != daisy) {
			/* No corresponding device. */
			parport_unregister_device(dev);
			return NULL;
		}
	}

	return dev;
}

/**
 *	parport_close - close a device opened with parport_open()
 *	@dev: device to close
 *
 *	This is to parport_open() as parport_unregister_device() is to
 *	parport_register_device().
 **/

void parport_close(struct pardevice *dev)
{
	parport_unregister_device(dev);
}

/**
 *	parport_device_num - convert device coordinates
 *	@parport: parallel port number
 *	@mux: multiplexor port number (-1 for no multiplexor)
 *	@daisy: daisy chain address (-1 for no daisy chain address)
 *
 *	This tries to locate a device on the given parallel port,
 *	multiplexor port and daisy chain address, and returns its
 *	device number or %-ENXIO if no device with those coordinates
 *	exists.
 **/

int parport_device_num(int parport, int mux, int daisy)
{
	int res = -ENXIO;
	struct daisydev *dev;

	spin_lock(&topology_lock);
	dev = topology;
	while (dev && dev->port->portnum != parport &&
	       dev->port->muxport != mux && dev->daisy != daisy)
		dev = dev->next;
	if (dev)
		res = dev->devnum;
	spin_unlock(&topology_lock);

	return res;
}

/* Send a daisy-chain-style CPP command packet. */
static int cpp_daisy(struct parport *port, int cmd)
{
	unsigned char s;

	parport_data_forward(port);
	parport_write_data(port, 0xaa); udelay(2);
	parport_write_data(port, 0x55); udelay(2);
	parport_write_data(port, 0x00); udelay(2);
	parport_write_data(port, 0xff); udelay(2);
	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_BUSY
		  | PARPORT_STATUS_PAPEROUT
		  | PARPORT_STATUS_SELECT
		  | PARPORT_STATUS_ERROR)) {
		DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
			 port->name, s);
		return -ENXIO;
	}

	parport_write_data(port, 0x87); udelay(2);
	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
		DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
			 port->name, s);
		return -ENXIO;
	}

	parport_write_data(port, 0x78); udelay(2);
	parport_write_data(port, cmd); udelay(2);
	parport_frob_control(port,
			      PARPORT_CONTROL_STROBE,
			      PARPORT_CONTROL_STROBE);
	udelay(1);
	s = parport_read_status(port);
	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
	udelay(1);
	parport_write_data(port, 0xff); udelay(2);

	return s;
}

/* Send a mux-style CPP command packet. */
static int cpp_mux(struct parport *port, int cmd)
{
	unsigned char s;
	int rc;

	parport_data_forward(port);
	parport_write_data(port, 0xaa); udelay(2);
	parport_write_data(port, 0x55); udelay(2);
	parport_write_data(port, 0xf0); udelay(2);
	parport_write_data(port, 0x0f); udelay(2);
	parport_write_data(port, 0x52); udelay(2);
	parport_write_data(port, 0xad); udelay(2);
	parport_write_data(port, cmd); udelay(2);

	s = parport_read_status(port);
	if (!(s & PARPORT_STATUS_ACK)) {
		DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
			 port->name, cmd, s);
		return -EIO;
	}

	rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
	      ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
	      ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
	      ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));

	return rc;
}

void parport_daisy_deselect_all(struct parport *port)
{
	cpp_daisy(port, 0x30);
}

int parport_daisy_select(struct parport *port, int daisy, int mode)
{
	switch (mode)
	{
		// For these modes we should switch to EPP mode:
		case IEEE1284_MODE_EPP:
		case IEEE1284_MODE_EPPSL:
		case IEEE1284_MODE_EPPSWE:
			return !(cpp_daisy(port, 0x20 + daisy) &
				 PARPORT_STATUS_ERROR);

		// For these modes we should switch to ECP mode:
		case IEEE1284_MODE_ECP:
		case IEEE1284_MODE_ECPRLE:
		case IEEE1284_MODE_ECPSWE: 
			return !(cpp_daisy(port, 0xd0 + daisy) &
				 PARPORT_STATUS_ERROR);

		// Nothing was told for BECP in Daisy chain specification.
		// May be it's wise to use ECP?
		case IEEE1284_MODE_BECP:
		// Others use compat mode
		case IEEE1284_MODE_NIBBLE:
		case IEEE1284_MODE_BYTE:
		case IEEE1284_MODE_COMPAT:
		default:
			return !(cpp_daisy(port, 0xe0 + daisy) &
				 PARPORT_STATUS_ERROR);
	}
}

static int mux_present(struct parport *port)
{
	return cpp_mux(port, 0x51) == 3;
}

static int num_mux_ports(struct parport *port)
{
	return cpp_mux(port, 0x58);
}

static int select_port(struct parport *port)
{
	int muxport = port->muxport;
	return cpp_mux(port, 0x60 + muxport) == muxport;
}

static int assign_addrs(struct parport *port)
{
	unsigned char s;
	unsigned char daisy;
	int thisdev = numdevs;
	int detected;
	char *deviceid;

	parport_data_forward(port);
	parport_write_data(port, 0xaa); udelay(2);
	parport_write_data(port, 0x55); udelay(2);
	parport_write_data(port, 0x00); udelay(2);
	parport_write_data(port, 0xff); udelay(2);
	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_BUSY
		  | PARPORT_STATUS_PAPEROUT
		  | PARPORT_STATUS_SELECT
		  | PARPORT_STATUS_ERROR)) {
		DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
			 port->name, s);
		return 0;
	}

	parport_write_data(port, 0x87); udelay(2);
	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
					  | PARPORT_STATUS_PAPEROUT
					  | PARPORT_STATUS_SELECT
					  | PARPORT_STATUS_ERROR);
	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
		DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
			 port->name, s);
		return 0;
	}

	parport_write_data(port, 0x78); udelay(2);
	s = parport_read_status(port);

	for (daisy = 0;
	     (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT))
		     == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)
		     && daisy < 4;
	     ++daisy) {
		parport_write_data(port, daisy);
		udelay(2);
		parport_frob_control(port,
				      PARPORT_CONTROL_STROBE,
				      PARPORT_CONTROL_STROBE);
		udelay(1);
		parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
		udelay(1);

		add_dev(numdevs++, port, daisy);

		/* See if this device thought it was the last in the
		 * chain. */
		if (!(s & PARPORT_STATUS_BUSY))
			break;

		/* We are seeing pass through status now. We see
		   last_dev from next device or if last_dev does not
		   work status lines from some non-daisy chain
		   device. */
		s = parport_read_status(port);
	}

	parport_write_data(port, 0xff); udelay(2);
	detected = numdevs - thisdev;
	DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
		 detected);

	/* Ask the new devices to introduce themselves. */
	deviceid = kmalloc(1024, GFP_KERNEL);
	if (!deviceid) return 0;

	for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
		parport_device_id(thisdev, deviceid, 1024);

	kfree(deviceid);
	return detected;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IEEE 1284.3 Parallel port daisy chain and multiplexor code
	3	*
	4	* Copyright (C) 1999, 2000 Tim Waugh <tim@cyberelk.demon.co.uk>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	* ??-12-1998: Initial implementation.
	12	* 31-01-1999: Make port-cloning transparent.
	13	* 13-02-1999: Move DeviceID technique from parport_probe.
	14	* 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too.
	15	* 22-02-2000: Count devices that are actually detected.
	16	*
	17	* Any part of this program may be used in documents licensed under
	18	* the GNU Free Documentation License, Version 1.1 or any later version
	19	* published by the Free Software Foundation.
	20	*/
	21
	22	#include <linux/module.h>
	23	#include <linux/parport.h>
	24	#include <linux/delay.h>
	25	#include <linux/sched.h>
	26
	27	#include <asm/current.h>
	28	#include <asm/uaccess.h>
	29
	30	#undef DEBUG
	31
	32	#ifdef DEBUG
d32ccc43	33	#define DPRINTK(stuff...) printk(stuff)
1da177e4 LT	34	#else
	35	#define DPRINTK(stuff...)
	36	#endif
	37
	38	static struct daisydev {
	39	struct daisydev *next;
	40	struct parport *port;
	41	int daisy;
	42	int devnum;
	43	} *topology = NULL;
	44	static DEFINE_SPINLOCK(topology_lock);
	45
	46	static int numdevs = 0;
	47
	48	/* Forward-declaration of lower-level functions. */
d32ccc43 MM	49	static int mux_present(struct parport *port);
	50	static int num_mux_ports(struct parport *port);
	51	static int select_port(struct parport *port);
	52	static int assign_addrs(struct parport *port);
1da177e4 LT	53
1da177e4 LT	54	/* Add a device to the discovered topology. */
d32ccc43	55	static void add_dev(int devnum, struct parport *port, int daisy)
1da177e4 LT	56	{
1da177e4 LT	57	struct daisydev newdev, *p;
d32ccc43	58	newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL);
1da177e4 LT	59	if (newdev) {
	60	newdev->port = port;
	61	newdev->daisy = daisy;
	62	newdev->devnum = devnum;
	63	spin_lock(&topology_lock);
	64	for (p = &topology; p && (p)->devnum<devnum; p = &(*p)->next)
	65	;
	66	newdev->next = *p;
	67	*p = newdev;
	68	spin_unlock(&topology_lock);
	69	}
	70	}
	71
	72	/* Clone a parport (actually, make an alias). */
d32ccc43	73	static struct parport clone_parport(struct parport real, int muxport)
1da177e4	74	{
d32ccc43	75	struct parport *extra = parport_register_port(real->base,
1da177e4 LT	76	real->irq,
	77	real->dma,
	78	real->ops);
	79	if (extra) {
	80	extra->portnum = real->portnum;
	81	extra->physport = real;
	82	extra->muxport = muxport;
	83	real->slaves[muxport-1] = extra;
	84	}
	85
	86	return extra;
	87	}
	88
	89	/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
	90	* Return value is number of devices actually detected. */
d32ccc43	91	int parport_daisy_init(struct parport *port)
1da177e4 LT	92	{
	93	int detected = 0;
	94	char *deviceid;
	95	static const char th[] = { /0*/"th", "st", "nd", "rd", "th" };
	96	int num_ports;
	97	int i;
	98	int last_try = 0;
	99
	100	again:
	101	/* Because this is called before any other devices exist,
	102	* we don't have to claim exclusive access. */
	103
	104	/* If mux present on normal port, need to create new
	105	* parports for each extra port. */
d32ccc43	106	if (port->muxport < 0 && mux_present(port) &&
1da177e4	107	/* don't be fooled: a mux must have 2 or 4 ports. */
d32ccc43	108	((num_ports = num_mux_ports(port)) == 2 \|\| num_ports == 4)) {
1da177e4 LT	109	/* Leave original as port zero. */
1da177e4 LT	110	port->muxport = 0;
d32ccc43	111	printk(KERN_INFO
1da177e4 LT	112	"%s: 1st (default) port of %d-way multiplexor\n",
	113	port->name, num_ports);
	114	for (i = 1; i < num_ports; i++) {
	115	/* Clone the port. */
d32ccc43	116	struct parport *extra = clone_parport(port, i);
1da177e4	117	if (!extra) {
d32ccc43	118	if (signal_pending(current))
1da177e4 LT	119	break;
1da177e4 LT	120
d32ccc43	121	schedule();
1da177e4 LT	122	continue;
	123	}
	124
d32ccc43	125	printk(KERN_INFO
1da177e4 LT	126	"%s: %d%s port of %d-way multiplexor on %s\n",
	127	extra->name, i + 1, th[i + 1], num_ports,
	128	port->name);
	129
	130	/* Analyse that port too. We won't recurse
	131	forever because of the 'port->muxport < 0'
	132	test above. */
	133	parport_daisy_init(extra);
	134	}
	135	}
	136
	137	if (port->muxport >= 0)
d32ccc43	138	select_port(port);
1da177e4	139
d32ccc43 MM	140	parport_daisy_deselect_all(port);
d32ccc43 MM	141	detected += assign_addrs(port);
1da177e4 LT	142
1da177e4 LT	143	/* Count the potential legacy device at the end. */
d32ccc43	144	add_dev(numdevs++, port, -1);
1da177e4 LT	145
1da177e4 LT	146	/* Find out the legacy device's IEEE 1284 device ID. */
d32ccc43	147	deviceid = kmalloc(1024, GFP_KERNEL);
1da177e4	148	if (deviceid) {
d32ccc43	149	if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
1da177e4 LT	150	detected++;
1da177e4 LT	151
d32ccc43	152	kfree(deviceid);
1da177e4 LT	153	}
	154
	155	if (!detected && !last_try) {
	156	/* No devices were detected. Perhaps they are in some
	157	funny state; let's try to reset them and see if
	158	they wake up. */
d32ccc43 MM	159	parport_daisy_fini(port);
	160	parport_write_control(port, PARPORT_CONTROL_SELECT);
	161	udelay(50);
	162	parport_write_control(port,
1da177e4 LT	163	PARPORT_CONTROL_SELECT \|
1da177e4 LT	164	PARPORT_CONTROL_INIT);
d32ccc43	165	udelay(50);
1da177e4 LT	166	last_try = 1;
	167	goto again;
	168	}
	169
	170	return detected;
	171	}
	172
	173	/* Forget about devices on a physical port. */
d32ccc43	174	void parport_daisy_fini(struct parport *port)
1da177e4 LT	175	{
	176	struct daisydev **p;
	177
	178	spin_lock(&topology_lock);
	179	p = &topology;
	180	while (*p) {
	181	struct daisydev dev = p;
	182	if (dev->port != port) {
	183	p = &dev->next;
	184	continue;
	185	}
	186	*p = dev->next;
	187	kfree(dev);
	188	}
	189
	190	/* Gaps in the numbering could be handled better. How should
	191	someone enumerate through all IEEE1284.3 devices in the
	192	topology?. */
	193	if (!topology) numdevs = 0;
	194	spin_unlock(&topology_lock);
	195	return;
	196	}
	197
	198	/**
	199	* parport_open - find a device by canonical device number
	200	* @devnum: canonical device number
	201	* @name: name to associate with the device
	202	* @pf: preemption callback
	203	* @kf: kick callback
	204	* @irqf: interrupt handler
	205	* @flags: registration flags
	206	* @handle: driver data
	207	*
	208	* This function is similar to parport_register_device(), except
	209	* that it locates a device by its number rather than by the port
	210	* it is attached to.
	211	*
	212	* All parameters except for @devnum are the same as for
	213	* parport_register_device(). The return value is the same as
	214	* for parport_register_device().
	215	**/
	216
d32ccc43	217	struct pardevice parport_open(int devnum, const char name,
1da177e4	218	int (pf) (void ), void (kf) (void ),
7d12e780	219	void (irqf) (int, void ),
1da177e4 LT	220	int flags, void *handle)
	221	{
	222	struct daisydev *p = topology;
	223	struct parport *port;
	224	struct pardevice *dev;
	225	int daisy;
	226
	227	spin_lock(&topology_lock);
	228	while (p && p->devnum != devnum)
	229	p = p->next;
	230
	231	if (!p) {
	232	spin_unlock(&topology_lock);
	233	return NULL;
	234	}
	235
	236	daisy = p->daisy;
	237	port = parport_get_port(p->port);
	238	spin_unlock(&topology_lock);
	239
d32ccc43	240	dev = parport_register_device(port, name, pf, kf,
1da177e4 LT	241	irqf, flags, handle);
	242	parport_put_port(port);
	243	if (!dev)
	244	return NULL;
	245
	246	dev->daisy = daisy;
	247
	248	/* Check that there really is a device to select. */
	249	if (daisy >= 0) {
	250	int selected;
d32ccc43	251	parport_claim_or_block(dev);
1da177e4	252	selected = port->daisy;
d32ccc43	253	parport_release(dev);
1da177e4	254
c29a75ed	255	if (selected != daisy) {
1da177e4	256	/* No corresponding device. */
d32ccc43	257	parport_unregister_device(dev);
1da177e4 LT	258	return NULL;
	259	}
	260	}
	261
	262	return dev;
	263	}
	264
	265	/**
	266	* parport_close - close a device opened with parport_open()
	267	* @dev: device to close
	268	*
	269	* This is to parport_open() as parport_unregister_device() is to
	270	* parport_register_device().
	271	**/
	272
d32ccc43	273	void parport_close(struct pardevice *dev)
1da177e4	274	{
d32ccc43	275	parport_unregister_device(dev);
1da177e4 LT	276	}
	277
	278	/**
	279	* parport_device_num - convert device coordinates
	280	* @parport: parallel port number
	281	* @mux: multiplexor port number (-1 for no multiplexor)
	282	* @daisy: daisy chain address (-1 for no daisy chain address)
	283	*
	284	* This tries to locate a device on the given parallel port,
	285	* multiplexor port and daisy chain address, and returns its
7d469722	286	* device number or %-ENXIO if no device with those coordinates
1da177e4 LT	287	* exists.
	288	**/
	289
d32ccc43	290	int parport_device_num(int parport, int mux, int daisy)
1da177e4 LT	291	{
	292	int res = -ENXIO;
	293	struct daisydev *dev;
	294
	295	spin_lock(&topology_lock);
	296	dev = topology;
	297	while (dev && dev->port->portnum != parport &&
	298	dev->port->muxport != mux && dev->daisy != daisy)
	299	dev = dev->next;
	300	if (dev)
	301	res = dev->devnum;
	302	spin_unlock(&topology_lock);
	303
	304	return res;
	305	}
	306
	307	/* Send a daisy-chain-style CPP command packet. */
d32ccc43	308	static int cpp_daisy(struct parport *port, int cmd)
1da177e4 LT	309	{
	310	unsigned char s;
	311
d32ccc43 MM	312	parport_data_forward(port);
	313	parport_write_data(port, 0xaa); udelay(2);
	314	parport_write_data(port, 0x55); udelay(2);
	315	parport_write_data(port, 0x00); udelay(2);
	316	parport_write_data(port, 0xff); udelay(2);
	317	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	318	\| PARPORT_STATUS_PAPEROUT
	319	\| PARPORT_STATUS_SELECT
	320	\| PARPORT_STATUS_ERROR);
	321	if (s != (PARPORT_STATUS_BUSY
	322	\| PARPORT_STATUS_PAPEROUT
	323	\| PARPORT_STATUS_SELECT
	324	\| PARPORT_STATUS_ERROR)) {
d32ccc43	325	DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
1da177e4 LT	326	port->name, s);
	327	return -ENXIO;
	328	}
	329
d32ccc43 MM	330	parport_write_data(port, 0x87); udelay(2);
d32ccc43 MM	331	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	332	\| PARPORT_STATUS_PAPEROUT
	333	\| PARPORT_STATUS_SELECT
	334	\| PARPORT_STATUS_ERROR);
	335	if (s != (PARPORT_STATUS_SELECT \| PARPORT_STATUS_ERROR)) {
d32ccc43	336	DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
1da177e4 LT	337	port->name, s);
	338	return -ENXIO;
	339	}
	340
d32ccc43 MM	341	parport_write_data(port, 0x78); udelay(2);
	342	parport_write_data(port, cmd); udelay(2);
	343	parport_frob_control(port,
1da177e4 LT	344	PARPORT_CONTROL_STROBE,
1da177e4 LT	345	PARPORT_CONTROL_STROBE);
d32ccc43 MM	346	udelay(1);
	347	s = parport_read_status(port);
	348	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
	349	udelay(1);
	350	parport_write_data(port, 0xff); udelay(2);
1da177e4 LT	351
	352	return s;
	353	}
	354
	355	/* Send a mux-style CPP command packet. */
d32ccc43	356	static int cpp_mux(struct parport *port, int cmd)
1da177e4 LT	357	{
	358	unsigned char s;
	359	int rc;
	360
d32ccc43 MM	361	parport_data_forward(port);
	362	parport_write_data(port, 0xaa); udelay(2);
	363	parport_write_data(port, 0x55); udelay(2);
	364	parport_write_data(port, 0xf0); udelay(2);
	365	parport_write_data(port, 0x0f); udelay(2);
	366	parport_write_data(port, 0x52); udelay(2);
	367	parport_write_data(port, 0xad); udelay(2);
	368	parport_write_data(port, cmd); udelay(2);
1da177e4	369
d32ccc43	370	s = parport_read_status(port);
1da177e4	371	if (!(s & PARPORT_STATUS_ACK)) {
d32ccc43	372	DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
1da177e4 LT	373	port->name, cmd, s);
	374	return -EIO;
	375	}
	376
	377	rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) \|
	378	((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) \|
	379	((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) \|
	380	((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3));
	381
	382	return rc;
	383	}
	384
d32ccc43	385	void parport_daisy_deselect_all(struct parport *port)
1da177e4	386	{
d32ccc43	387	cpp_daisy(port, 0x30);
1da177e4 LT	388	}
1da177e4 LT	389
d32ccc43	390	int parport_daisy_select(struct parport *port, int daisy, int mode)
1da177e4 LT	391	{
	392	switch (mode)
	393	{
	394	// For these modes we should switch to EPP mode:
	395	case IEEE1284_MODE_EPP:
	396	case IEEE1284_MODE_EPPSL:
	397	case IEEE1284_MODE_EPPSWE:
d32ccc43	398	return !(cpp_daisy(port, 0x20 + daisy) &
7c9cc3be	399	PARPORT_STATUS_ERROR);
1da177e4 LT	400
	401	// For these modes we should switch to ECP mode:
	402	case IEEE1284_MODE_ECP:
	403	case IEEE1284_MODE_ECPRLE:
	404	case IEEE1284_MODE_ECPSWE:
d32ccc43	405	return !(cpp_daisy(port, 0xd0 + daisy) &
7c9cc3be	406	PARPORT_STATUS_ERROR);
1da177e4 LT	407
	408	// Nothing was told for BECP in Daisy chain specification.
	409	// May be it's wise to use ECP?
	410	case IEEE1284_MODE_BECP:
	411	// Others use compat mode
	412	case IEEE1284_MODE_NIBBLE:
	413	case IEEE1284_MODE_BYTE:
	414	case IEEE1284_MODE_COMPAT:
	415	default:
d32ccc43	416	return !(cpp_daisy(port, 0xe0 + daisy) &
7c9cc3be	417	PARPORT_STATUS_ERROR);
1da177e4 LT	418	}
	419	}
	420
d32ccc43	421	static int mux_present(struct parport *port)
1da177e4	422	{
d32ccc43	423	return cpp_mux(port, 0x51) == 3;
1da177e4 LT	424	}
1da177e4 LT	425
d32ccc43	426	static int num_mux_ports(struct parport *port)
1da177e4	427	{
d32ccc43	428	return cpp_mux(port, 0x58);
1da177e4 LT	429	}
1da177e4 LT	430
d32ccc43	431	static int select_port(struct parport *port)
1da177e4 LT	432	{
1da177e4 LT	433	int muxport = port->muxport;
d32ccc43	434	return cpp_mux(port, 0x60 + muxport) == muxport;
1da177e4 LT	435	}
1da177e4 LT	436
d32ccc43	437	static int assign_addrs(struct parport *port)
1da177e4	438	{
310c8c32	439	unsigned char s;
1da177e4 LT	440	unsigned char daisy;
	441	int thisdev = numdevs;
	442	int detected;
	443	char *deviceid;
	444
d32ccc43 MM	445	parport_data_forward(port);
	446	parport_write_data(port, 0xaa); udelay(2);
	447	parport_write_data(port, 0x55); udelay(2);
	448	parport_write_data(port, 0x00); udelay(2);
	449	parport_write_data(port, 0xff); udelay(2);
	450	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	451	\| PARPORT_STATUS_PAPEROUT
	452	\| PARPORT_STATUS_SELECT
	453	\| PARPORT_STATUS_ERROR);
	454	if (s != (PARPORT_STATUS_BUSY
	455	\| PARPORT_STATUS_PAPEROUT
	456	\| PARPORT_STATUS_SELECT
	457	\| PARPORT_STATUS_ERROR)) {
d32ccc43	458	DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
1da177e4 LT	459	port->name, s);
	460	return 0;
	461	}
	462
d32ccc43 MM	463	parport_write_data(port, 0x87); udelay(2);
d32ccc43 MM	464	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	465	\| PARPORT_STATUS_PAPEROUT
	466	\| PARPORT_STATUS_SELECT
	467	\| PARPORT_STATUS_ERROR);
	468	if (s != (PARPORT_STATUS_SELECT \| PARPORT_STATUS_ERROR)) {
d32ccc43	469	DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
1da177e4 LT	470	port->name, s);
	471	return 0;
	472	}
	473
d32ccc43 MM	474	parport_write_data(port, 0x78); udelay(2);
d32ccc43 MM	475	s = parport_read_status(port);
1da177e4	476
310c8c32 MK	477	for (daisy = 0;
	478	(s & (PARPORT_STATUS_PAPEROUT\|PARPORT_STATUS_SELECT))
	479	== (PARPORT_STATUS_PAPEROUT\|PARPORT_STATUS_SELECT)
	480	&& daisy < 4;
	481	++daisy) {
d32ccc43 MM	482	parport_write_data(port, daisy);
	483	udelay(2);
	484	parport_frob_control(port,
1da177e4 LT	485	PARPORT_CONTROL_STROBE,
1da177e4 LT	486	PARPORT_CONTROL_STROBE);
d32ccc43 MM	487	udelay(1);
	488	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
	489	udelay(1);
1da177e4	490
d32ccc43	491	add_dev(numdevs++, port, daisy);
1da177e4	492
310c8c32 MK	493	/* See if this device thought it was the last in the
	494	* chain. */
	495	if (!(s & PARPORT_STATUS_BUSY))
	496	break;
1da177e4	497
310c8c32 MK	498	/* We are seeing pass through status now. We see
	499	last_dev from next device or if last_dev does not
	500	work status lines from some non-daisy chain
	501	device. */
d32ccc43	502	s = parport_read_status(port);
1da177e4 LT	503	}
1da177e4 LT	504
d32ccc43	505	parport_write_data(port, 0xff); udelay(2);
1da177e4	506	detected = numdevs - thisdev;
d32ccc43	507	DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
1da177e4 LT	508	detected);
	509
	510	/* Ask the new devices to introduce themselves. */
d32ccc43	511	deviceid = kmalloc(1024, GFP_KERNEL);
1da177e4 LT	512	if (!deviceid) return 0;
	513
	514	for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
d32ccc43	515	parport_device_id(thisdev, deviceid, 1024);
1da177e4	516
d32ccc43	517	kfree(deviceid);
1da177e4 LT	518	return detected;
1da177e4 LT	519	}