[linux-block.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/slab.h>
#include <linux/sched/signal.h>

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

#undef DEBUG

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

static int numdevs;
static bool daisy_init_done;

/* 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;
}

static int daisy_drv_probe(struct pardevice *par_dev)
{
	struct device_driver *drv = par_dev->dev.driver;

	if (strcmp(drv->name, "daisy_drv"))
		return -ENODEV;
	if (strcmp(par_dev->name, daisy_dev_name))
		return -ENODEV;

	return 0;
}

static struct parport_driver daisy_driver = {
	.name = "daisy_drv",
	.probe = daisy_drv_probe,
};

/* 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;

	if (!daisy_init_done) {
		/*
		 * flag should be marked true first as
		 * parport_register_driver() might try to load the low
		 * level driver which will lead to announcing new ports
		 * and which will again come back here at
		 * parport_daisy_init()
		 */
		daisy_init_done = true;
		i = parport_register_driver(&daisy_driver);
		if (i) {
			pr_err("daisy registration failed\n");
			daisy_init_done = false;
			return i;
		}
	}

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;
		pr_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;
			}

			pr_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
 *
 *	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)
{
	struct daisydev *p = topology;
	struct pardev_cb par_cb;
	struct parport *port;
	struct pardevice *dev;
	int daisy;

	memset(&par_cb, 0, sizeof(par_cb));
	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_dev_model(port, name, &par_cb, devnum);
	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);
}

/* 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)) {
		pr_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)) {
		pr_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)) {
		pr_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)) {
		pr_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)) {
		pr_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;
	pr_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>
5a0e3ad6	25	#include <linux/slab.h>
174cd4b1	26	#include <linux/sched/signal.h>
1da177e4 LT	27
1da177e4 LT	28	#include <asm/current.h>
7c0f6ba6	29	#include <linux/uaccess.h>
1da177e4 LT	30
	31	#undef DEBUG
	32
1da177e4 LT	33	static struct daisydev {
	34	struct daisydev *next;
	35	struct parport *port;
	36	int daisy;
	37	int devnum;
	38	} *topology = NULL;
	39	static DEFINE_SPINLOCK(topology_lock);
	40
df4c756e	41	static int numdevs;
60f8a59d	42	static bool daisy_init_done;
1da177e4 LT	43
1da177e4 LT	44	/* Forward-declaration of lower-level functions. */
d32ccc43 MM	45	static int mux_present(struct parport *port);
	46	static int num_mux_ports(struct parport *port);
	47	static int select_port(struct parport *port);
	48	static int assign_addrs(struct parport *port);
1da177e4 LT	49
1da177e4 LT	50	/* Add a device to the discovered topology. */
d32ccc43	51	static void add_dev(int devnum, struct parport *port, int daisy)
1da177e4 LT	52	{
1da177e4 LT	53	struct daisydev newdev, *p;
d32ccc43	54	newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL);
1da177e4 LT	55	if (newdev) {
	56	newdev->port = port;
	57	newdev->daisy = daisy;
	58	newdev->devnum = devnum;
	59	spin_lock(&topology_lock);
	60	for (p = &topology; p && (p)->devnum<devnum; p = &(*p)->next)
	61	;
	62	newdev->next = *p;
	63	*p = newdev;
	64	spin_unlock(&topology_lock);
	65	}
	66	}
	67
	68	/* Clone a parport (actually, make an alias). */
d32ccc43	69	static struct parport clone_parport(struct parport real, int muxport)
1da177e4	70	{
d32ccc43	71	struct parport *extra = parport_register_port(real->base,
1da177e4 LT	72	real->irq,
	73	real->dma,
	74	real->ops);
	75	if (extra) {
	76	extra->portnum = real->portnum;
	77	extra->physport = real;
	78	extra->muxport = muxport;
	79	real->slaves[muxport-1] = extra;
	80	}
	81
	82	return extra;
	83	}
	84
60f8a59d SM	85	static int daisy_drv_probe(struct pardevice *par_dev)
	86	{
	87	struct device_driver *drv = par_dev->dev.driver;
	88
	89	if (strcmp(drv->name, "daisy_drv"))
	90	return -ENODEV;
	91	if (strcmp(par_dev->name, daisy_dev_name))
	92	return -ENODEV;
	93
	94	return 0;
	95	}
	96
	97	static struct parport_driver daisy_driver = {
	98	.name = "daisy_drv",
	99	.probe = daisy_drv_probe,
60f8a59d SM	100	};
60f8a59d SM	101
1da177e4 LT	102	/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
1da177e4 LT	103	* Return value is number of devices actually detected. */
d32ccc43	104	int parport_daisy_init(struct parport *port)
1da177e4 LT	105	{
	106	int detected = 0;
	107	char *deviceid;
	108	static const char th[] = { /0*/"th", "st", "nd", "rd", "th" };
	109	int num_ports;
	110	int i;
	111	int last_try = 0;
	112
60f8a59d SM	113	if (!daisy_init_done) {
	114	/*
	115	* flag should be marked true first as
	116	* parport_register_driver() might try to load the low
	117	* level driver which will lead to announcing new ports
	118	* and which will again come back here at
	119	* parport_daisy_init()
	120	*/
	121	daisy_init_done = true;
	122	i = parport_register_driver(&daisy_driver);
	123	if (i) {
	124	pr_err("daisy registration failed\n");
	125	daisy_init_done = false;
	126	return i;
	127	}
	128	}
	129
1da177e4 LT	130	again:
	131	/* Because this is called before any other devices exist,
	132	* we don't have to claim exclusive access. */
	133
	134	/* If mux present on normal port, need to create new
	135	* parports for each extra port. */
d32ccc43	136	if (port->muxport < 0 && mux_present(port) &&
1da177e4	137	/* don't be fooled: a mux must have 2 or 4 ports. */
d32ccc43	138	((num_ports = num_mux_ports(port)) == 2 \|\| num_ports == 4)) {
1da177e4 LT	139	/* Leave original as port zero. */
1da177e4 LT	140	port->muxport = 0;
decf26f6	141	pr_info("%s: 1st (default) port of %d-way multiplexor\n",
1da177e4 LT	142	port->name, num_ports);
	143	for (i = 1; i < num_ports; i++) {
	144	/* Clone the port. */
d32ccc43	145	struct parport *extra = clone_parport(port, i);
1da177e4	146	if (!extra) {
d32ccc43	147	if (signal_pending(current))
1da177e4 LT	148	break;
1da177e4 LT	149
d32ccc43	150	schedule();
1da177e4 LT	151	continue;
	152	}
	153
decf26f6	154	pr_info("%s: %d%s port of %d-way multiplexor on %s\n",
1da177e4 LT	155	extra->name, i + 1, th[i + 1], num_ports,
	156	port->name);
	157
	158	/* Analyse that port too. We won't recurse
	159	forever because of the 'port->muxport < 0'
	160	test above. */
	161	parport_daisy_init(extra);
	162	}
	163	}
	164
	165	if (port->muxport >= 0)
d32ccc43	166	select_port(port);
1da177e4	167
d32ccc43 MM	168	parport_daisy_deselect_all(port);
d32ccc43 MM	169	detected += assign_addrs(port);
1da177e4 LT	170
1da177e4 LT	171	/* Count the potential legacy device at the end. */
d32ccc43	172	add_dev(numdevs++, port, -1);
1da177e4 LT	173
1da177e4 LT	174	/* Find out the legacy device's IEEE 1284 device ID. */
d32ccc43	175	deviceid = kmalloc(1024, GFP_KERNEL);
1da177e4	176	if (deviceid) {
d32ccc43	177	if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
1da177e4 LT	178	detected++;
1da177e4 LT	179
d32ccc43	180	kfree(deviceid);
1da177e4 LT	181	}
	182
	183	if (!detected && !last_try) {
	184	/* No devices were detected. Perhaps they are in some
	185	funny state; let's try to reset them and see if
	186	they wake up. */
d32ccc43 MM	187	parport_daisy_fini(port);
	188	parport_write_control(port, PARPORT_CONTROL_SELECT);
	189	udelay(50);
	190	parport_write_control(port,
1da177e4 LT	191	PARPORT_CONTROL_SELECT \|
1da177e4 LT	192	PARPORT_CONTROL_INIT);
d32ccc43	193	udelay(50);
1da177e4 LT	194	last_try = 1;
	195	goto again;
	196	}
	197
	198	return detected;
	199	}
	200
	201	/* Forget about devices on a physical port. */
d32ccc43	202	void parport_daisy_fini(struct parport *port)
1da177e4 LT	203	{
	204	struct daisydev **p;
	205
	206	spin_lock(&topology_lock);
	207	p = &topology;
	208	while (*p) {
	209	struct daisydev dev = p;
	210	if (dev->port != port) {
	211	p = &dev->next;
	212	continue;
	213	}
	214	*p = dev->next;
	215	kfree(dev);
	216	}
	217
	218	/* Gaps in the numbering could be handled better. How should
	219	someone enumerate through all IEEE1284.3 devices in the
	220	topology?. */
	221	if (!topology) numdevs = 0;
	222	spin_unlock(&topology_lock);
	223	return;
	224	}
	225
	226	/**
	227	* parport_open - find a device by canonical device number
	228	* @devnum: canonical device number
	229	* @name: name to associate with the device
1da177e4 LT	230	*
	231	* This function is similar to parport_register_device(), except
	232	* that it locates a device by its number rather than by the port
	233	* it is attached to.
	234	*
	235	* All parameters except for @devnum are the same as for
	236	* parport_register_device(). The return value is the same as
	237	* for parport_register_device().
	238	**/
	239
5712cb3d	240	struct pardevice parport_open(int devnum, const char name)
1da177e4 LT	241	{
1da177e4 LT	242	struct daisydev *p = topology;
60f8a59d	243	struct pardev_cb par_cb;
1da177e4 LT	244	struct parport *port;
	245	struct pardevice *dev;
	246	int daisy;
	247
60f8a59d	248	memset(&par_cb, 0, sizeof(par_cb));
1da177e4 LT	249	spin_lock(&topology_lock);
	250	while (p && p->devnum != devnum)
	251	p = p->next;
	252
	253	if (!p) {
	254	spin_unlock(&topology_lock);
	255	return NULL;
	256	}
	257
	258	daisy = p->daisy;
	259	port = parport_get_port(p->port);
	260	spin_unlock(&topology_lock);
	261
60f8a59d	262	dev = parport_register_dev_model(port, name, &par_cb, devnum);
1da177e4 LT	263	parport_put_port(port);
	264	if (!dev)
	265	return NULL;
	266
	267	dev->daisy = daisy;
	268
	269	/* Check that there really is a device to select. */
	270	if (daisy >= 0) {
	271	int selected;
d32ccc43	272	parport_claim_or_block(dev);
1da177e4	273	selected = port->daisy;
d32ccc43	274	parport_release(dev);
1da177e4	275
c29a75ed	276	if (selected != daisy) {
1da177e4	277	/* No corresponding device. */
d32ccc43	278	parport_unregister_device(dev);
1da177e4 LT	279	return NULL;
	280	}
	281	}
	282
	283	return dev;
	284	}
	285
	286	/**
	287	* parport_close - close a device opened with parport_open()
	288	* @dev: device to close
	289	*
	290	* This is to parport_open() as parport_unregister_device() is to
	291	* parport_register_device().
	292	**/
	293
d32ccc43	294	void parport_close(struct pardevice *dev)
1da177e4	295	{
d32ccc43	296	parport_unregister_device(dev);
1da177e4 LT	297	}
1da177e4 LT	298
1da177e4	299	/* Send a daisy-chain-style CPP command packet. */
d32ccc43	300	static int cpp_daisy(struct parport *port, int cmd)
1da177e4 LT	301	{
	302	unsigned char s;
	303
d32ccc43 MM	304	parport_data_forward(port);
	305	parport_write_data(port, 0xaa); udelay(2);
	306	parport_write_data(port, 0x55); udelay(2);
	307	parport_write_data(port, 0x00); udelay(2);
	308	parport_write_data(port, 0xff); udelay(2);
	309	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	310	\| PARPORT_STATUS_PAPEROUT
	311	\| PARPORT_STATUS_SELECT
	312	\| PARPORT_STATUS_ERROR);
	313	if (s != (PARPORT_STATUS_BUSY
	314	\| PARPORT_STATUS_PAPEROUT
	315	\| PARPORT_STATUS_SELECT
	316	\| PARPORT_STATUS_ERROR)) {
88c5cbde	317	pr_debug("%s: cpp_daisy: aa5500ff(%02x)\n", port->name, s);
1da177e4 LT	318	return -ENXIO;
	319	}
	320
d32ccc43 MM	321	parport_write_data(port, 0x87); udelay(2);
d32ccc43 MM	322	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	323	\| PARPORT_STATUS_PAPEROUT
	324	\| PARPORT_STATUS_SELECT
	325	\| PARPORT_STATUS_ERROR);
	326	if (s != (PARPORT_STATUS_SELECT \| PARPORT_STATUS_ERROR)) {
88c5cbde	327	pr_debug("%s: cpp_daisy: aa5500ff87(%02x)\n", port->name, s);
1da177e4 LT	328	return -ENXIO;
	329	}
	330
d32ccc43 MM	331	parport_write_data(port, 0x78); udelay(2);
	332	parport_write_data(port, cmd); udelay(2);
	333	parport_frob_control(port,
1da177e4 LT	334	PARPORT_CONTROL_STROBE,
1da177e4 LT	335	PARPORT_CONTROL_STROBE);
d32ccc43 MM	336	udelay(1);
	337	s = parport_read_status(port);
	338	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
	339	udelay(1);
	340	parport_write_data(port, 0xff); udelay(2);
1da177e4 LT	341
	342	return s;
	343	}
	344
	345	/* Send a mux-style CPP command packet. */
d32ccc43	346	static int cpp_mux(struct parport *port, int cmd)
1da177e4 LT	347	{
	348	unsigned char s;
	349	int rc;
	350
d32ccc43 MM	351	parport_data_forward(port);
	352	parport_write_data(port, 0xaa); udelay(2);
	353	parport_write_data(port, 0x55); udelay(2);
	354	parport_write_data(port, 0xf0); udelay(2);
	355	parport_write_data(port, 0x0f); udelay(2);
	356	parport_write_data(port, 0x52); udelay(2);
	357	parport_write_data(port, 0xad); udelay(2);
	358	parport_write_data(port, cmd); udelay(2);
1da177e4	359
d32ccc43	360	s = parport_read_status(port);
1da177e4	361	if (!(s & PARPORT_STATUS_ACK)) {
88c5cbde	362	pr_debug("%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
1da177e4 LT	363	port->name, cmd, s);
	364	return -EIO;
	365	}
	366
	367	rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) \|
	368	((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) \|
	369	((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) \|
	370	((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3));
	371
	372	return rc;
	373	}
	374
d32ccc43	375	void parport_daisy_deselect_all(struct parport *port)
1da177e4	376	{
d32ccc43	377	cpp_daisy(port, 0x30);
1da177e4 LT	378	}
1da177e4 LT	379
d32ccc43	380	int parport_daisy_select(struct parport *port, int daisy, int mode)
1da177e4 LT	381	{
	382	switch (mode)
	383	{
	384	// For these modes we should switch to EPP mode:
	385	case IEEE1284_MODE_EPP:
	386	case IEEE1284_MODE_EPPSL:
	387	case IEEE1284_MODE_EPPSWE:
d32ccc43	388	return !(cpp_daisy(port, 0x20 + daisy) &
7c9cc3be	389	PARPORT_STATUS_ERROR);
1da177e4 LT	390
	391	// For these modes we should switch to ECP mode:
	392	case IEEE1284_MODE_ECP:
	393	case IEEE1284_MODE_ECPRLE:
	394	case IEEE1284_MODE_ECPSWE:
d32ccc43	395	return !(cpp_daisy(port, 0xd0 + daisy) &
7c9cc3be	396	PARPORT_STATUS_ERROR);
1da177e4 LT	397
	398	// Nothing was told for BECP in Daisy chain specification.
	399	// May be it's wise to use ECP?
	400	case IEEE1284_MODE_BECP:
	401	// Others use compat mode
	402	case IEEE1284_MODE_NIBBLE:
	403	case IEEE1284_MODE_BYTE:
	404	case IEEE1284_MODE_COMPAT:
	405	default:
d32ccc43	406	return !(cpp_daisy(port, 0xe0 + daisy) &
7c9cc3be	407	PARPORT_STATUS_ERROR);
1da177e4 LT	408	}
	409	}
	410
d32ccc43	411	static int mux_present(struct parport *port)
1da177e4	412	{
d32ccc43	413	return cpp_mux(port, 0x51) == 3;
1da177e4 LT	414	}
1da177e4 LT	415
d32ccc43	416	static int num_mux_ports(struct parport *port)
1da177e4	417	{
d32ccc43	418	return cpp_mux(port, 0x58);
1da177e4 LT	419	}
1da177e4 LT	420
d32ccc43	421	static int select_port(struct parport *port)
1da177e4 LT	422	{
1da177e4 LT	423	int muxport = port->muxport;
d32ccc43	424	return cpp_mux(port, 0x60 + muxport) == muxport;
1da177e4 LT	425	}
1da177e4 LT	426
d32ccc43	427	static int assign_addrs(struct parport *port)
1da177e4	428	{
310c8c32	429	unsigned char s;
1da177e4 LT	430	unsigned char daisy;
	431	int thisdev = numdevs;
	432	int detected;
	433	char *deviceid;
	434
d32ccc43 MM	435	parport_data_forward(port);
	436	parport_write_data(port, 0xaa); udelay(2);
	437	parport_write_data(port, 0x55); udelay(2);
	438	parport_write_data(port, 0x00); udelay(2);
	439	parport_write_data(port, 0xff); udelay(2);
	440	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	441	\| PARPORT_STATUS_PAPEROUT
	442	\| PARPORT_STATUS_SELECT
	443	\| PARPORT_STATUS_ERROR);
	444	if (s != (PARPORT_STATUS_BUSY
	445	\| PARPORT_STATUS_PAPEROUT
	446	\| PARPORT_STATUS_SELECT
	447	\| PARPORT_STATUS_ERROR)) {
88c5cbde	448	pr_debug("%s: assign_addrs: aa5500ff(%02x)\n", port->name, s);
1da177e4 LT	449	return 0;
	450	}
	451
d32ccc43 MM	452	parport_write_data(port, 0x87); udelay(2);
d32ccc43 MM	453	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
1da177e4 LT	454	\| PARPORT_STATUS_PAPEROUT
	455	\| PARPORT_STATUS_SELECT
	456	\| PARPORT_STATUS_ERROR);
	457	if (s != (PARPORT_STATUS_SELECT \| PARPORT_STATUS_ERROR)) {
88c5cbde	458	pr_debug("%s: assign_addrs: aa5500ff87(%02x)\n", port->name, s);
1da177e4 LT	459	return 0;
	460	}
	461
d32ccc43 MM	462	parport_write_data(port, 0x78); udelay(2);
d32ccc43 MM	463	s = parport_read_status(port);
1da177e4	464
310c8c32 MK	465	for (daisy = 0;
	466	(s & (PARPORT_STATUS_PAPEROUT\|PARPORT_STATUS_SELECT))
	467	== (PARPORT_STATUS_PAPEROUT\|PARPORT_STATUS_SELECT)
	468	&& daisy < 4;
	469	++daisy) {
d32ccc43 MM	470	parport_write_data(port, daisy);
	471	udelay(2);
	472	parport_frob_control(port,
1da177e4 LT	473	PARPORT_CONTROL_STROBE,
1da177e4 LT	474	PARPORT_CONTROL_STROBE);
d32ccc43 MM	475	udelay(1);
	476	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
	477	udelay(1);
1da177e4	478
d32ccc43	479	add_dev(numdevs++, port, daisy);
1da177e4	480
310c8c32 MK	481	/* See if this device thought it was the last in the
	482	* chain. */
	483	if (!(s & PARPORT_STATUS_BUSY))
	484	break;
1da177e4	485
310c8c32 MK	486	/* We are seeing pass through status now. We see
	487	last_dev from next device or if last_dev does not
	488	work status lines from some non-daisy chain
	489	device. */
d32ccc43	490	s = parport_read_status(port);
1da177e4 LT	491	}
1da177e4 LT	492
d32ccc43	493	parport_write_data(port, 0xff); udelay(2);
1da177e4	494	detected = numdevs - thisdev;
88c5cbde	495	pr_debug("%s: Found %d daisy-chained devices\n", port->name, detected);
1da177e4 LT	496
1da177e4 LT	497	/* Ask the new devices to introduce themselves. */
d32ccc43	498	deviceid = kmalloc(1024, GFP_KERNEL);
1da177e4 LT	499	if (!deviceid) return 0;
	500
	501	for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
d32ccc43	502	parport_device_id(thisdev, deviceid, 1024);
1da177e4	503
d32ccc43	504	kfree(deviceid);
1da177e4 LT	505	return detected;
1da177e4 LT	506	}