File: /usr/src/linux/drivers/parport/daisy.c
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/parport.h>
23 #include <linux/delay.h>
24 #include <asm/uaccess.h>
25
26 #define DEBUG /* undef me for production */
27
28 #ifdef DEBUG
29 #define DPRINTK(stuff...) printk (stuff)
30 #else
31 #define DPRINTK(stuff...)
32 #endif
33
34 static struct daisydev {
35 struct daisydev *next;
36 struct parport *port;
37 int daisy;
38 int devnum;
39 } *topology = NULL;
40
41 static int numdevs = 0;
42
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);
48
49 /* Add a device to the discovered topology. */
50 static void add_dev (int devnum, struct parport *port, int daisy)
51 {
52 struct daisydev *newdev;
53 newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL);
54 if (newdev) {
55 newdev->port = port;
56 newdev->daisy = daisy;
57 newdev->devnum = devnum;
58 newdev->next = topology;
59 if (!topology || topology->devnum >= devnum)
60 topology = newdev;
61 else {
62 struct daisydev *prev = topology;
63 while (prev->next && prev->next->devnum < devnum)
64 prev = prev->next;
65 newdev->next = prev->next;
66 prev->next = newdev;
67 }
68 }
69 }
70
71 /* Clone a parport (actually, make an alias). */
72 static struct parport *clone_parport (struct parport *real, int muxport)
73 {
74 struct parport *extra = parport_register_port (real->base,
75 real->irq,
76 real->dma,
77 real->ops);
78 if (extra) {
79 extra->portnum = real->portnum;
80 extra->physport = real;
81 extra->muxport = muxport;
82 }
83
84 return extra;
85 }
86
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)
90 {
91 int detected = 0;
92 char *deviceid;
93 static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
94 int num_ports;
95 int i;
96
97 /* Because this is called before any other devices exist,
98 * we don't have to claim exclusive access. */
99
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. */
106 port->muxport = 0;
107 printk (KERN_INFO
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);
113 if (!extra) {
114 if (signal_pending (current))
115 break;
116
117 schedule ();
118 continue;
119 }
120
121 printk (KERN_INFO
122 "%s: %d%s port of %d-way multiplexor on %s\n",
123 extra->name, i + 1, th[i + 1], num_ports,
124 port->name);
125
126 /* Analyse that port too. We won't recurse
127 forever because of the 'port->muxport < 0'
128 test above. */
129 parport_announce_port (extra);
130 }
131 }
132
133 if (port->muxport >= 0)
134 select_port (port);
135
136 parport_daisy_deselect_all (port);
137 detected += assign_addrs (port);
138
139 /* Count the potential legacy device at the end. */
140 add_dev (numdevs++, port, -1);
141
142 /* Find out the legacy device's IEEE 1284 device ID. */
143 deviceid = kmalloc (1000, GFP_KERNEL);
144 if (deviceid) {
145 if (parport_device_id (numdevs - 1, deviceid, 1000) > 2)
146 detected++;
147
148 kfree (deviceid);
149 }
150
151 return detected;
152 }
153
154 /* Forget about devices on a physical port. */
155 void parport_daisy_fini (struct parport *port)
156 {
157 struct daisydev *dev, *prev = topology;
158 while (prev && prev->port == port) {
159 topology = topology->next;
160 kfree (prev);
161 prev = topology;
162 }
163
164 while (prev) {
165 dev = prev->next;
166 if (dev && dev->port == port) {
167 prev->next = dev->next;
168 kfree (dev);
169 }
170 prev = prev->next;
171 }
172
173 /* Gaps in the numbering could be handled better. How should
174 someone enumerate through all IEEE1284.3 devices in the
175 topology?. */
176 if (!topology) numdevs = 0;
177 return;
178 }
179
180 /**
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
185 * @kf: kick callback
186 * @irqf: interrupt handler
187 * @flags: registration flags
188 * @handle: driver data
189 *
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().
194 *
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().
198 **/
199
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)
204 {
205 struct parport *port = parport_enumerate ();
206 struct pardevice *dev;
207 int portnum;
208 int muxnum;
209 int daisynum;
210
211 if (parport_device_coords (devnum, &portnum, &muxnum, &daisynum))
212 return NULL;
213
214 while (port && ((port->portnum != portnum) ||
215 (port->muxport != muxnum)))
216 port = port->next;
217
218 if (!port)
219 /* No corresponding parport. */
220 return NULL;
221
222 dev = parport_register_device (port, name, pf, kf,
223 irqf, flags, handle);
224 if (dev)
225 dev->daisy = daisynum;
226
227 /* Check that there really is a device to select. */
228 if (daisynum >= 0) {
229 int selected;
230 parport_claim_or_block (dev);
231 selected = port->daisy;
232 parport_release (dev);
233
234 if (selected != port->daisy) {
235 /* No corresponding device. */
236 parport_unregister_device (dev);
237 return NULL;
238 }
239 }
240
241 return dev;
242 }
243
244 /**
245 * parport_close - close a device opened with parport_open()
246 * @dev: device to close
247 *
248 * This is to parport_open() as parport_unregister_device() is to
249 * parport_register_device().
250 **/
251
252 void parport_close (struct pardevice *dev)
253 {
254 parport_unregister_device (dev);
255 }
256
257 /**
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)
262 *
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
266 * exists.
267 **/
268
269 int parport_device_num (int parport, int mux, int daisy)
270 {
271 struct daisydev *dev = topology;
272
273 while (dev && dev->port->portnum != parport &&
274 dev->port->muxport != mux && dev->daisy != daisy)
275 dev = dev->next;
276
277 if (!dev)
278 return -ENXIO;
279
280 return dev->devnum;
281 }
282
283 /**
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
289 *
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.
295 *
296 * The caller must allocate storage for @parport, @mux, and
297 * @daisy.
298 *
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.
303 *
304 * This function is not actually very useful, but this interface
305 * was suggested by IEEE 1284.3.
306 **/
307
308 int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
309 {
310 struct daisydev *dev = topology;
311
312 while (dev && dev->devnum != devnum)
313 dev = dev->next;
314
315 if (!dev)
316 return -ENXIO;
317
318 if (parport) *parport = dev->port->portnum;
319 if (mux) *mux = dev->port->muxport;
320 if (daisy) *daisy = dev->daisy;
321 return 0;
322 }
323
324 /* Send a daisy-chain-style CPP command packet. */
325 static int cpp_daisy (struct parport *port, int cmd)
326 {
327 unsigned char s;
328
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",
343 port->name, s);
344 return -ENXIO;
345 }
346
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",
354 port->name, s);
355 return -ENXIO;
356 }
357
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);
363 udelay (1);
364 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
365 udelay (1);
366 s = parport_read_status (port);
367 parport_write_data (port, 0xff); udelay (2);
368
369 return s;
370 }
371
372 /* Send a mux-style CPP command packet. */
373 static int cpp_mux (struct parport *port, int cmd)
374 {
375 unsigned char s;
376 int rc;
377
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);
386
387 s = parport_read_status (port);
388 if (!(s & PARPORT_STATUS_ACK)) {
389 DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
390 port->name, cmd, s);
391 return -EIO;
392 }
393
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));
398
399 return rc;
400 }
401
402 void parport_daisy_deselect_all (struct parport *port)
403 {
404 cpp_daisy (port, 0x30);
405 }
406
407 int parport_daisy_select (struct parport *port, int daisy, int mode)
408 {
409 /* mode is currently ignored. FIXME? */
410 return cpp_daisy (port, 0xe0 + daisy) & PARPORT_STATUS_ERROR;
411 }
412
413 static int mux_present (struct parport *port)
414 {
415 return cpp_mux (port, 0x51) == 3;
416 }
417
418 static int num_mux_ports (struct parport *port)
419 {
420 return cpp_mux (port, 0x58);
421 }
422
423 static int select_port (struct parport *port)
424 {
425 int muxport = port->muxport;
426 return cpp_mux (port, 0x60 + muxport) == muxport;
427 }
428
429 static int assign_addrs (struct parport *port)
430 {
431 unsigned char s, last_dev;
432 unsigned char daisy;
433 int thisdev = numdevs;
434 int detected;
435 char *deviceid;
436
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",
451 port->name, s);
452 return 0;
453 }
454
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",
462 port->name, s);
463 return 0;
464 }
465
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. */
469
470 for (daisy = 0; daisy < 4; daisy++) {
471 parport_write_data (port, daisy);
472 udelay (2);
473 parport_frob_control (port,
474 PARPORT_CONTROL_STROBE,
475 PARPORT_CONTROL_STROBE);
476 udelay (1);
477 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
478 udelay (1);
479
480 if (last_dev)
481 /* No more devices. */
482 break;
483
484 last_dev = !(parport_read_status (port)
485 & PARPORT_STATUS_BUSY);
486
487 add_dev (numdevs++, port, daisy);
488 }
489
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,
493 detected);
494
495 /* Ask the new devices to introduce themselves. */
496 deviceid = kmalloc (1000, GFP_KERNEL);
497 if (!deviceid) return 0;
498
499 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
500 parport_device_id (thisdev, deviceid, 1000);
501
502 kfree (deviceid);
503 return detected;
504 }
505
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. */
509
510 /**
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
515 * new search
516 *
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.
520 *
521 * When a device is found matching those requirements, its device
522 * number is returned; if there is no matching device, a negative
523 * value is returned.
524 *
525 * A new search it initiated by passing %NULL as the @from
526 * argument. If @from is not %NULL, the search continues from
527 * that device.
528 **/
529
530 int parport_find_device (const char *mfg, const char *mdl, int from)
531 {
532 struct daisydev *d = topology; /* sorted by devnum */
533
534 /* Find where to start. */
535 while (d && d->devnum <= from)
536 d = d->next;
537
538 /* Search. */
539 while (d) {
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)))
544 break;
545
546 d = d->next;
547 }
548
549 if (d)
550 return d->devnum;
551
552 return -1;
553 }
554
555 /**
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
559 * new search
560 *
561 * This walks through the list of parallel port devices looking
562 * for a device whose 'CLS' string matches @cls in their IEEE
563 * 1284 Device ID.
564 *
565 * When a device is found matching those requirements, its device
566 * number is returned; if there is no matching device, a negative
567 * value is returned.
568 *
569 * A new search it initiated by passing %NULL as the @from
570 * argument. If @from is not %NULL, the search continues from
571 * that device.
572 **/
573
574 int parport_find_class (parport_device_class cls, int from)
575 {
576 struct daisydev *d = topology; /* sorted by devnum */
577
578 /* Find where to start. */
579 while (d && d->devnum <= from)
580 d = d->next;
581
582 /* Search. */
583 while (d && d->port->probe_info[1 + d->daisy].class != cls)
584 d = d->next;
585
586 if (d)
587 return d->devnum;
588
589 return -1;
590 }
591