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
33 #define DPRINTK(stuff...) printk (stuff)
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. */
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);
53
54 /* Add a device to the discovered topology. */
55 static void add_dev (int devnum, struct parport *port, int daisy)
56 {
57 struct daisydev *newdev, **p;
58 newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL);
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). */
73 static struct parport *clone_parport (struct parport *real, int muxport)
74 {
75 struct parport *extra = parport_register_port (real->base,
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. */
91 int parport_daisy_init (struct parport *port)
92 {
93 int detected = 0;
94 char *deviceid;
95 static const char *th[] = { /**/"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. */
106 if (port->muxport < 0 && mux_present (port) &&
107 /* don't be fooled: a mux must have 2 or 4 ports. */
108 ((num_ports = num_mux_ports (port)) == 2 || num_ports == 4)) {
109 /* Leave original as port zero. */
110 port->muxport = 0;
111 printk (KERN_INFO
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. */
116 struct parport *extra = clone_parport (port, i);
117 if (!extra) {
118 if (signal_pending (current))
119 break;
120
121 schedule ();
122 continue;
123 }
124
125 printk (KERN_INFO
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)
138 select_port (port);
139
140 parport_daisy_deselect_all (port);
141 detected += assign_addrs (port);
142
143 /* Count the potential legacy device at the end. */
144 add_dev (numdevs++, port, -1);
145
146 /* Find out the legacy device's IEEE 1284 device ID. */
147 deviceid = kmalloc (1000, GFP_KERNEL);
148 if (deviceid) {
149 if (parport_device_id (numdevs - 1, deviceid, 1000) > 2)
150 detected++;
151
152 kfree (deviceid);
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. */
159 parport_daisy_fini (port);
160 parport_write_control (port, PARPORT_CONTROL_SELECT);
161 udelay (50);
162 parport_write_control (port,
163 PARPORT_CONTROL_SELECT |
164 PARPORT_CONTROL_INIT);
165 udelay (50);
166 last_try = 1;
167 goto again;
168 }
169
170 return detected;
171 }
172
173 /* Forget about devices on a physical port. */
174 void parport_daisy_fini (struct parport *port)
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
217 struct pardevice *parport_open (int devnum, const char *name,
218 int (*pf) (void *), void (*kf) (void *),
219 void (*irqf) (int, void *, struct pt_regs *),
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
240 dev = parport_register_device (port, name, pf, kf,
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;
251 parport_claim_or_block (dev);
252 selected = port->daisy;
253 parport_release (dev);
254
255 if (selected != port->daisy) {
256 /* No corresponding device. */
257 parport_unregister_device (dev);
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
273 void parport_close (struct pardevice *dev)
274 {
275 parport_unregister_device (dev);
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
286 * device number or -NXIO if no device with those coordinates
287 * exists.
288 **/
289
290 int parport_device_num (int parport, int mux, int daisy)
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. */
308 static int cpp_daisy (struct parport *port, int cmd)
309 {
310 unsigned char s;
311
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
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)) {
325 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
326 port->name, s);
327 return -ENXIO;
328 }
329
330 parport_write_data (port, 0x87); udelay (2);
331 s = parport_read_status (port) & (PARPORT_STATUS_BUSY
332 | PARPORT_STATUS_PAPEROUT
333 | PARPORT_STATUS_SELECT
334 | PARPORT_STATUS_ERROR);
335 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
336 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
337 port->name, s);
338 return -ENXIO;
339 }
340
341 parport_write_data (port, 0x78); udelay (2);
342 parport_write_data (port, cmd); udelay (2);
343 parport_frob_control (port,
344 PARPORT_CONTROL_STROBE,
345 PARPORT_CONTROL_STROBE);
346 udelay (1);
347 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
348 udelay (1);
349 s = parport_read_status (port);
350 parport_write_data (port, 0xff); udelay (2);
351
352 return s;
353 }
354
355 /* Send a mux-style CPP command packet. */
356 static int cpp_mux (struct parport *port, int cmd)
357 {
358 unsigned char s;
359 int rc;
360
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);
369
370 s = parport_read_status (port);
371 if (!(s & PARPORT_STATUS_ACK)) {
372 DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
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
385 void parport_daisy_deselect_all (struct parport *port)
386 {
387 cpp_daisy (port, 0x30);
388 }
389
390 int parport_daisy_select (struct parport *port, int daisy, int mode)
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:
398 return (cpp_daisy (port, 0x20 + daisy) &
399 PARPORT_STATUS_ERROR);
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:
405 return (cpp_daisy (port, 0xd0 + daisy) &
406 PARPORT_STATUS_ERROR);
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:
416 return (cpp_daisy (port, 0xe0 + daisy) &
417 PARPORT_STATUS_ERROR);
418 }
419 }
420
421 static int mux_present (struct parport *port)
422 {
423 return cpp_mux (port, 0x51) == 3;
424 }
425
426 static int num_mux_ports (struct parport *port)
427 {
428 return cpp_mux (port, 0x58);
429 }
430
431 static int select_port (struct parport *port)
432 {
433 int muxport = port->muxport;
434 return cpp_mux (port, 0x60 + muxport) == muxport;
435 }
436
437 static int assign_addrs (struct parport *port)
438 {
439 unsigned char s, last_dev;
440 unsigned char daisy;
441 int thisdev = numdevs;
442 int detected;
443 char *deviceid;
444
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
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)) {
458 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
459 port->name, s);
460 return 0;
461 }
462
463 parport_write_data (port, 0x87); udelay (2);
464 s = parport_read_status (port) & (PARPORT_STATUS_BUSY
465 | PARPORT_STATUS_PAPEROUT
466 | PARPORT_STATUS_SELECT
467 | PARPORT_STATUS_ERROR);
468 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
469 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
470 port->name, s);
471 return 0;
472 }
473
474 parport_write_data (port, 0x78); udelay (2);
475 last_dev = 0; /* We've just been speaking to a device, so we
476 know there must be at least _one_ out there. */
477
478 for (daisy = 0; daisy < 4; daisy++) {
479 parport_write_data (port, daisy);
480 udelay (2);
481 parport_frob_control (port,
482 PARPORT_CONTROL_STROBE,
483 PARPORT_CONTROL_STROBE);
484 udelay (1);
485 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
486 udelay (1);
487
488 if (last_dev)
489 /* No more devices. */
490 break;
491
492 last_dev = !(parport_read_status (port)
493 & PARPORT_STATUS_BUSY);
494
495 add_dev (numdevs++, port, daisy);
496 }
497
498 parport_write_data (port, 0xff); udelay (2);
499 detected = numdevs - thisdev;
500 DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
501 detected);
502
503 /* Ask the new devices to introduce themselves. */
504 deviceid = kmalloc (1000, GFP_KERNEL);
505 if (!deviceid) return 0;
506
507 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
508 parport_device_id (thisdev, deviceid, 1000);
509
510 kfree (deviceid);
511 return detected;
512 }
513
|
This page was automatically generated by the
LXR engine.
|