2 * IEEE 1284.3 Parallel port daisy chain and multiplexor code
4 * Copyright (C) 1999, 2000 Tim Waugh <tim@cyberelk.demon.co.uk>
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.
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.
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.
22 #include <linux/parport.h>
23 #include <linux/delay.h>
24 #include <asm/uaccess.h>
26 #define DEBUG /* undef me for production */
29 #define DPRINTK(stuff...) printk (stuff)
31 #define DPRINTK(stuff...)
34 static struct daisydev
{
35 struct daisydev
*next
;
41 static int numdevs
= 0;
43 /* Forward-declaration of lower-level functions. */
44 static int mux_present (struct parport
*port
);
45 static int num_mux_ports (struct parport
*port
);
46 static int select_port (struct parport
*port
);
47 static int assign_addrs (struct parport
*port
);
49 /* Add a device to the discovered topology. */
50 static void add_dev (int devnum
, struct parport
*port
, int daisy
)
52 struct daisydev
*newdev
;
53 newdev
= kmalloc (sizeof (struct daisydev
), GFP_KERNEL
);
56 newdev
->daisy
= daisy
;
57 newdev
->devnum
= devnum
;
58 newdev
->next
= topology
;
59 if (!topology
|| topology
->devnum
>= devnum
)
62 struct daisydev
*prev
= topology
;
63 while (prev
->next
&& prev
->next
->devnum
< devnum
)
65 newdev
->next
= prev
->next
;
71 /* Clone a parport (actually, make an alias). */
72 static struct parport
*clone_parport (struct parport
*real
, int muxport
)
74 struct parport
*extra
= parport_register_port (real
->base
,
79 extra
->portnum
= real
->portnum
;
80 extra
->physport
= real
;
81 extra
->muxport
= muxport
;
87 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
88 * Return value is number of devices actually detected. */
89 int parport_daisy_init (struct parport
*port
)
93 static const char *th
[] = { /*0*/"th", "st", "nd", "rd", "th" };
97 /* Because this is called before any other devices exist,
98 * we don't have to claim exclusive access. */
100 /* If mux present on normal port, need to create new
101 * parports for each extra port. */
102 if (port
->muxport
< 0 && mux_present (port
) &&
103 /* don't be fooled: a mux must have 2 or 4 ports. */
104 ((num_ports
= num_mux_ports (port
)) == 2 || num_ports
== 4)) {
105 /* Leave original as port zero. */
108 "%s: 1st (default) port of %d-way multiplexor\n",
109 port
->name
, num_ports
);
110 for (i
= 1; i
< num_ports
; i
++) {
111 /* Clone the port. */
112 struct parport
*extra
= clone_parport (port
, i
);
114 if (signal_pending (current
))
122 "%s: %d%s port of %d-way multiplexor on %s\n",
123 extra
->name
, i
+ 1, th
[i
+ 1], num_ports
,
126 /* Analyse that port too. We won't recurse
127 forever because of the 'port->muxport < 0'
129 parport_announce_port (extra
);
133 if (port
->muxport
>= 0)
136 parport_daisy_deselect_all (port
);
137 detected
+= assign_addrs (port
);
139 /* Count the potential legacy device at the end. */
140 add_dev (numdevs
++, port
, -1);
142 /* Find out the legacy device's IEEE 1284 device ID. */
143 deviceid
= kmalloc (1000, GFP_KERNEL
);
145 if (parport_device_id (numdevs
- 1, deviceid
, 1000) > 2)
154 /* Forget about devices on a physical port. */
155 void parport_daisy_fini (struct parport
*port
)
157 struct daisydev
*dev
, *prev
= topology
;
158 while (prev
&& prev
->port
== port
) {
159 topology
= topology
->next
;
166 if (dev
&& dev
->port
== port
) {
167 prev
->next
= dev
->next
;
173 /* Gaps in the numbering could be handled better. How should
174 someone enumerate through all IEEE1284.3 devices in the
176 if (!topology
) numdevs
= 0;
181 * parport_open - find a device by canonical device number
182 * @devnum: canonical device number
183 * @name: name to associate with the device
184 * @pf: preemption callback
186 * @irqf: interrupt handler
187 * @flags: registration flags
188 * @handle: driver data
190 * This function is similar to parport_register_device(), except
191 * that it locates a device by its number rather than by the port
192 * it is attached to. See parport_find_device() and
193 * parport_find_class().
195 * All parameters except for @devnum are the same as for
196 * parport_register_device(). The return value is the same as
197 * for parport_register_device().
200 struct pardevice
*parport_open (int devnum
, const char *name
,
201 int (*pf
) (void *), void (*kf
) (void *),
202 void (*irqf
) (int, void *, struct pt_regs
*),
203 int flags
, void *handle
)
205 struct parport
*port
= parport_enumerate ();
206 struct pardevice
*dev
;
211 if (parport_device_coords (devnum
, &portnum
, &muxnum
, &daisynum
))
214 while (port
&& ((port
->portnum
!= portnum
) ||
215 (port
->muxport
!= muxnum
)))
219 /* No corresponding parport. */
222 dev
= parport_register_device (port
, name
, pf
, kf
,
223 irqf
, flags
, handle
);
225 dev
->daisy
= daisynum
;
227 /* Check that there really is a device to select. */
230 parport_claim_or_block (dev
);
231 selected
= port
->daisy
;
232 parport_release (dev
);
234 if (selected
!= port
->daisy
) {
235 /* No corresponding device. */
236 parport_unregister_device (dev
);
245 * parport_close - close a device opened with parport_open()
246 * @dev: device to close
248 * This is to parport_open() as parport_unregister_device() is to
249 * parport_register_device().
252 void parport_close (struct pardevice
*dev
)
254 parport_unregister_device (dev
);
258 * parport_device_num - convert device coordinates
259 * @parport: parallel port number
260 * @mux: multiplexor port number (-1 for no multiplexor)
261 * @daisy: daisy chain address (-1 for no daisy chain address)
263 * This tries to locate a device on the given parallel port,
264 * multiplexor port and daisy chain address, and returns its
265 * device number or -NXIO if no device with those coordinates
269 int parport_device_num (int parport
, int mux
, int daisy
)
271 struct daisydev
*dev
= topology
;
273 while (dev
&& dev
->port
->portnum
!= parport
&&
274 dev
->port
->muxport
!= mux
&& dev
->daisy
!= daisy
)
284 * parport_device_coords - convert canonical device number
285 * @devnum: device number
286 * @parport: pointer to storage for parallel port number
287 * @mux: pointer to storage for multiplexor port number
288 * @daisy: pointer to storage for daisy chain address
290 * This function converts a device number into its coordinates in
291 * terms of which parallel port in the system it is attached to,
292 * which multiplexor port it is attached to if there is a
293 * multiplexor on that port, and which daisy chain address it has
294 * if it is in a daisy chain.
296 * The caller must allocate storage for @parport, @mux, and
299 * If there is no device with the specified device number, -ENXIO
300 * is returned. Otherwise, the values pointed to by @parport,
301 * @mux, and @daisy are set to the coordinates of the device,
302 * with -1 for coordinates with no value.
304 * This function is not actually very useful, but this interface
305 * was suggested by IEEE 1284.3.
308 int parport_device_coords (int devnum
, int *parport
, int *mux
, int *daisy
)
310 struct daisydev
*dev
= topology
;
312 while (dev
&& dev
->devnum
!= devnum
)
318 if (parport
) *parport
= dev
->port
->portnum
;
319 if (mux
) *mux
= dev
->port
->muxport
;
320 if (daisy
) *daisy
= dev
->daisy
;
324 /* Send a daisy-chain-style CPP command packet. */
325 static int cpp_daisy (struct parport
*port
, int cmd
)
329 parport_data_forward (port
);
330 parport_write_data (port
, 0xaa); udelay (2);
331 parport_write_data (port
, 0x55); udelay (2);
332 parport_write_data (port
, 0x00); udelay (2);
333 parport_write_data (port
, 0xff); udelay (2);
334 s
= parport_read_status (port
) & (PARPORT_STATUS_BUSY
335 | PARPORT_STATUS_PAPEROUT
336 | PARPORT_STATUS_SELECT
337 | PARPORT_STATUS_ERROR
);
338 if (s
!= (PARPORT_STATUS_BUSY
339 | PARPORT_STATUS_PAPEROUT
340 | PARPORT_STATUS_SELECT
341 | PARPORT_STATUS_ERROR
)) {
342 DPRINTK (KERN_DEBUG
"%s: cpp_daisy: aa5500ff(%02x)\n",
347 parport_write_data (port
, 0x87); udelay (2);
348 s
= parport_read_status (port
) & (PARPORT_STATUS_BUSY
349 | PARPORT_STATUS_PAPEROUT
350 | PARPORT_STATUS_SELECT
351 | PARPORT_STATUS_ERROR
);
352 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
353 DPRINTK (KERN_DEBUG
"%s: cpp_daisy: aa5500ff87(%02x)\n",
358 parport_write_data (port
, 0x78); udelay (2);
359 parport_write_data (port
, cmd
); udelay (2);
360 parport_frob_control (port
,
361 PARPORT_CONTROL_STROBE
,
362 PARPORT_CONTROL_STROBE
);
364 parport_frob_control (port
, PARPORT_CONTROL_STROBE
, 0);
366 s
= parport_read_status (port
);
367 parport_write_data (port
, 0xff); udelay (2);
372 /* Send a mux-style CPP command packet. */
373 static int cpp_mux (struct parport
*port
, int cmd
)
378 parport_data_forward (port
);
379 parport_write_data (port
, 0xaa); udelay (2);
380 parport_write_data (port
, 0x55); udelay (2);
381 parport_write_data (port
, 0xf0); udelay (2);
382 parport_write_data (port
, 0x0f); udelay (2);
383 parport_write_data (port
, 0x52); udelay (2);
384 parport_write_data (port
, 0xad); udelay (2);
385 parport_write_data (port
, cmd
); udelay (2);
387 s
= parport_read_status (port
);
388 if (!(s
& PARPORT_STATUS_ACK
)) {
389 DPRINTK (KERN_DEBUG
"%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
394 rc
= (((s
& PARPORT_STATUS_SELECT
? 1 : 0) << 0) |
395 ((s
& PARPORT_STATUS_PAPEROUT
? 1 : 0) << 1) |
396 ((s
& PARPORT_STATUS_BUSY
? 0 : 1) << 2) |
397 ((s
& PARPORT_STATUS_ERROR
? 0 : 1) << 3));
402 void parport_daisy_deselect_all (struct parport
*port
)
404 cpp_daisy (port
, 0x30);
407 int parport_daisy_select (struct parport
*port
, int daisy
, int mode
)
409 /* mode is currently ignored. FIXME? */
410 return cpp_daisy (port
, 0xe0 + daisy
) & PARPORT_STATUS_ERROR
;
413 static int mux_present (struct parport
*port
)
415 return cpp_mux (port
, 0x51) == 3;
418 static int num_mux_ports (struct parport
*port
)
420 return cpp_mux (port
, 0x58);
423 static int select_port (struct parport
*port
)
425 int muxport
= port
->muxport
;
426 return cpp_mux (port
, 0x60 + muxport
) == muxport
;
429 static int assign_addrs (struct parport
*port
)
431 unsigned char s
, last_dev
;
433 int thisdev
= numdevs
;
437 parport_data_forward (port
);
438 parport_write_data (port
, 0xaa); udelay (2);
439 parport_write_data (port
, 0x55); udelay (2);
440 parport_write_data (port
, 0x00); udelay (2);
441 parport_write_data (port
, 0xff); udelay (2);
442 s
= parport_read_status (port
) & (PARPORT_STATUS_BUSY
443 | PARPORT_STATUS_PAPEROUT
444 | PARPORT_STATUS_SELECT
445 | PARPORT_STATUS_ERROR
);
446 if (s
!= (PARPORT_STATUS_BUSY
447 | PARPORT_STATUS_PAPEROUT
448 | PARPORT_STATUS_SELECT
449 | PARPORT_STATUS_ERROR
)) {
450 DPRINTK (KERN_DEBUG
"%s: assign_addrs: aa5500ff(%02x)\n",
455 parport_write_data (port
, 0x87); udelay (2);
456 s
= parport_read_status (port
) & (PARPORT_STATUS_BUSY
457 | PARPORT_STATUS_PAPEROUT
458 | PARPORT_STATUS_SELECT
459 | PARPORT_STATUS_ERROR
);
460 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
461 DPRINTK (KERN_DEBUG
"%s: assign_addrs: aa5500ff87(%02x)\n",
466 parport_write_data (port
, 0x78); udelay (2);
467 last_dev
= 0; /* We've just been speaking to a device, so we
468 know there must be at least _one_ out there. */
470 for (daisy
= 0; daisy
< 4; daisy
++) {
471 parport_write_data (port
, daisy
);
473 parport_frob_control (port
,
474 PARPORT_CONTROL_STROBE
,
475 PARPORT_CONTROL_STROBE
);
477 parport_frob_control (port
, PARPORT_CONTROL_STROBE
, 0);
481 /* No more devices. */
484 last_dev
= !(parport_read_status (port
)
485 & PARPORT_STATUS_BUSY
);
487 add_dev (numdevs
++, port
, daisy
);
490 parport_write_data (port
, 0xff); udelay (2);
491 detected
= numdevs
- thisdev
;
492 DPRINTK (KERN_DEBUG
"%s: Found %d daisy-chained devices\n", port
->name
,
495 /* Ask the new devices to introduce themselves. */
496 deviceid
= kmalloc (1000, GFP_KERNEL
);
497 if (!deviceid
) return 0;
499 for (daisy
= 0; thisdev
< numdevs
; thisdev
++, daisy
++)
500 parport_device_id (thisdev
, deviceid
, 1000);
506 /* Find a device with a particular manufacturer and model string,
507 starting from a given device number. Like the PCI equivalent,
508 'from' itself is skipped. */
511 * parport_find_device - find a specific device
512 * @mfg: required manufacturer string
513 * @mdl: required model string
514 * @from: previous device number found in search, or %NULL for
517 * This walks through the list of parallel port devices looking
518 * for a device whose 'MFG' string matches @mfg and whose 'MDL'
519 * string matches @mdl in their IEEE 1284 Device ID.
521 * When a device is found matching those requirements, its device
522 * number is returned; if there is no matching device, a negative
525 * A new search it initiated by passing %NULL as the @from
526 * argument. If @from is not %NULL, the search continues from
530 int parport_find_device (const char *mfg
, const char *mdl
, int from
)
532 struct daisydev
*d
= topology
; /* sorted by devnum */
534 /* Find where to start. */
535 while (d
&& d
->devnum
<= from
)
540 struct parport_device_info
*info
;
541 info
= &d
->port
->probe_info
[1 + d
->daisy
];
542 if ((!mfg
|| !strcmp (mfg
, info
->mfr
)) &&
543 (!mdl
|| !strcmp (mdl
, info
->model
)))
556 * parport_find_class - find a device in a specified class
557 * @cls: required class
558 * @from: previous device number found in search, or %NULL for
561 * This walks through the list of parallel port devices looking
562 * for a device whose 'CLS' string matches @cls in their IEEE
565 * When a device is found matching those requirements, its device
566 * number is returned; if there is no matching device, a negative
569 * A new search it initiated by passing %NULL as the @from
570 * argument. If @from is not %NULL, the search continues from
574 int parport_find_class (parport_device_class cls
, int from
)
576 struct daisydev
*d
= topology
; /* sorted by devnum */
578 /* Find where to start. */
579 while (d
&& d
->devnum
<= from
)
583 while (d
&& d
->port
->probe_info
[1 + d
->daisy
].class != cls
)