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/*
* 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/parport.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#undef DEBUG /* undef me for production */
#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 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;
newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL);
if (newdev) {
newdev->port = port;
newdev->daisy = daisy;
newdev->devnum = devnum;
newdev->next = topology;
if (!topology || topology->devnum >= devnum)
topology = newdev;
else {
struct daisydev *prev = topology;
while (prev->next && prev->next->devnum < devnum)
prev = prev->next;
newdev->next = prev->next;
prev->next = newdev;
}
}
}
/* 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;
}
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;
/* 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_announce_port (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 (1000, GFP_KERNEL);
if (deviceid) {
if (parport_device_id (numdevs - 1, deviceid, 1000) > 2)
detected++;
kfree (deviceid);
}
return detected;
}
/* Forget about devices on a physical port. */
void parport_daisy_fini (struct parport *port)
{
struct daisydev *dev, *prev = topology;
while (prev && prev->port == port) {
topology = topology->next;
kfree (prev);
prev = topology;
}
while (prev) {
dev = prev->next;
if (dev && dev->port == port) {
prev->next = dev->next;
kfree (dev);
}
prev = prev->next;
}
/* Gaps in the numbering could be handled better. How should
someone enumerate through all IEEE1284.3 devices in the
topology?. */
if (!topology) numdevs = 0;
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. See parport_find_device() and
* parport_find_class().
*
* 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 *, struct pt_regs *),
int flags, void *handle)
{
struct parport *port = parport_enumerate ();
struct pardevice *dev;
int portnum;
int muxnum;
int daisynum;
if (parport_device_coords (devnum, &portnum, &muxnum, &daisynum))
return NULL;
while (port && ((port->portnum != portnum) ||
(port->muxport != muxnum)))
port = port->next;
if (!port)
/* No corresponding parport. */
return NULL;
dev = parport_register_device (port, name, pf, kf,
irqf, flags, handle);
if (dev)
dev->daisy = daisynum;
/* Check that there really is a device to select. */
if (daisynum >= 0) {
int selected;
parport_claim_or_block (dev);
selected = port->daisy;
parport_release (dev);
if (selected != port->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 -NXIO if no device with those coordinates
* exists.
**/
int parport_device_num (int parport, int mux, int daisy)
{
struct daisydev *dev = topology;
while (dev && dev->port->portnum != parport &&
dev->port->muxport != mux && dev->daisy != daisy)
dev = dev->next;
if (!dev)
return -ENXIO;
return dev->devnum;
}
/**
* parport_device_coords - convert canonical device number
* @devnum: device number
* @parport: pointer to storage for parallel port number
* @mux: pointer to storage for multiplexor port number
* @daisy: pointer to storage for daisy chain address
*
* This function converts a device number into its coordinates in
* terms of which parallel port in the system it is attached to,
* which multiplexor port it is attached to if there is a
* multiplexor on that port, and which daisy chain address it has
* if it is in a daisy chain.
*
* The caller must allocate storage for @parport, @mux, and
* @daisy.
*
* If there is no device with the specified device number, -ENXIO
* is returned. Otherwise, the values pointed to by @parport,
* @mux, and @daisy are set to the coordinates of the device,
* with -1 for coordinates with no value.
*
* This function is not actually very useful, but this interface
* was suggested by IEEE 1284.3.
**/
int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
{
struct daisydev *dev = topology;
while (dev && dev->devnum != devnum)
dev = dev->next;
if (!dev)
return -ENXIO;
if (parport) *parport = dev->port->portnum;
if (mux) *mux = dev->port->muxport;
if (daisy) *daisy = dev->daisy;
return 0;
}
/* 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);
parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
udelay (1);
s = parport_read_status (port);
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)
{
/* mode is currently ignored. FIXME? */
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, last_dev;
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);
last_dev = 0; /* We've just been speaking to a device, so we
know there must be at least _one_ out there. */
for (daisy = 0; 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);
if (last_dev)
/* No more devices. */
break;
last_dev = !(parport_read_status (port)
& PARPORT_STATUS_BUSY);
add_dev (numdevs++, port, daisy);
}
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 (1000, GFP_KERNEL);
if (!deviceid) return 0;
for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
parport_device_id (thisdev, deviceid, 1000);
kfree (deviceid);
return detected;
}
/* Find a device with a particular manufacturer and model string,
starting from a given device number. Like the PCI equivalent,
'from' itself is skipped. */
/**
* parport_find_device - find a specific device
* @mfg: required manufacturer string
* @mdl: required model string
* @from: previous device number found in search, or %NULL for
* new search
*
* This walks through the list of parallel port devices looking
* for a device whose 'MFG' string matches @mfg and whose 'MDL'
* string matches @mdl in their IEEE 1284 Device ID.
*
* When a device is found matching those requirements, its device
* number is returned; if there is no matching device, a negative
* value is returned.
*
* A new search it initiated by passing %NULL as the @from
* argument. If @from is not %NULL, the search continues from
* that device.
**/
int parport_find_device (const char *mfg, const char *mdl, int from)
{
struct daisydev *d = topology; /* sorted by devnum */
/* Find where to start. */
while (d && d->devnum <= from)
d = d->next;
/* Search. */
while (d) {
struct parport_device_info *info;
info = &d->port->probe_info[1 + d->daisy];
if ((!mfg || !strcmp (mfg, info->mfr)) &&
(!mdl || !strcmp (mdl, info->model)))
break;
d = d->next;
}
if (d)
return d->devnum;
return -1;
}
/**
* parport_find_class - find a device in a specified class
* @cls: required class
* @from: previous device number found in search, or %NULL for
* new search
*
* This walks through the list of parallel port devices looking
* for a device whose 'CLS' string matches @cls in their IEEE
* 1284 Device ID.
*
* When a device is found matching those requirements, its device
* number is returned; if there is no matching device, a negative
* value is returned.
*
* A new search it initiated by passing %NULL as the @from
* argument. If @from is not %NULL, the search continues from
* that device.
**/
int parport_find_class (parport_device_class cls, int from)
{
struct daisydev *d = topology; /* sorted by devnum */
/* Find where to start. */
while (d && d->devnum <= from)
d = d->next;
/* Search. */
while (d && d->port->probe_info[1 + d->daisy].class != cls)
d = d->next;
if (d)
return d->devnum;
return -1;
}
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