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/module.h>
23 #include <linux/parport.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/sched.h>
28 #include <asm/current.h>
29 #include <asm/uaccess.h>
34 #define DPRINTK(stuff...) printk(stuff)
36 #define DPRINTK(stuff...)
39 static struct daisydev
{
40 struct daisydev
*next
;
45 static DEFINE_SPINLOCK(topology_lock
);
47 static int numdevs
= 0;
49 /* Forward-declaration of lower-level functions. */
50 static int mux_present(struct parport
*port
);
51 static int num_mux_ports(struct parport
*port
);
52 static int select_port(struct parport
*port
);
53 static int assign_addrs(struct parport
*port
);
55 /* Add a device to the discovered topology. */
56 static void add_dev(int devnum
, struct parport
*port
, int daisy
)
58 struct daisydev
*newdev
, **p
;
59 newdev
= kmalloc(sizeof(struct daisydev
), GFP_KERNEL
);
62 newdev
->daisy
= daisy
;
63 newdev
->devnum
= devnum
;
64 spin_lock(&topology_lock
);
65 for (p
= &topology
; *p
&& (*p
)->devnum
<devnum
; p
= &(*p
)->next
)
69 spin_unlock(&topology_lock
);
73 /* Clone a parport (actually, make an alias). */
74 static struct parport
*clone_parport(struct parport
*real
, int muxport
)
76 struct parport
*extra
= parport_register_port(real
->base
,
81 extra
->portnum
= real
->portnum
;
82 extra
->physport
= real
;
83 extra
->muxport
= muxport
;
84 real
->slaves
[muxport
-1] = extra
;
90 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
91 * Return value is number of devices actually detected. */
92 int parport_daisy_init(struct parport
*port
)
96 static const char *th
[] = { /*0*/"th", "st", "nd", "rd", "th" };
102 /* Because this is called before any other devices exist,
103 * we don't have to claim exclusive access. */
105 /* If mux present on normal port, need to create new
106 * parports for each extra port. */
107 if (port
->muxport
< 0 && mux_present(port
) &&
108 /* don't be fooled: a mux must have 2 or 4 ports. */
109 ((num_ports
= num_mux_ports(port
)) == 2 || num_ports
== 4)) {
110 /* Leave original as port zero. */
113 "%s: 1st (default) port of %d-way multiplexor\n",
114 port
->name
, num_ports
);
115 for (i
= 1; i
< num_ports
; i
++) {
116 /* Clone the port. */
117 struct parport
*extra
= clone_parport(port
, i
);
119 if (signal_pending(current
))
127 "%s: %d%s port of %d-way multiplexor on %s\n",
128 extra
->name
, i
+ 1, th
[i
+ 1], num_ports
,
131 /* Analyse that port too. We won't recurse
132 forever because of the 'port->muxport < 0'
134 parport_daisy_init(extra
);
138 if (port
->muxport
>= 0)
141 parport_daisy_deselect_all(port
);
142 detected
+= assign_addrs(port
);
144 /* Count the potential legacy device at the end. */
145 add_dev(numdevs
++, port
, -1);
147 /* Find out the legacy device's IEEE 1284 device ID. */
148 deviceid
= kmalloc(1024, GFP_KERNEL
);
150 if (parport_device_id(numdevs
- 1, deviceid
, 1024) > 2)
156 if (!detected
&& !last_try
) {
157 /* No devices were detected. Perhaps they are in some
158 funny state; let's try to reset them and see if
160 parport_daisy_fini(port
);
161 parport_write_control(port
, PARPORT_CONTROL_SELECT
);
163 parport_write_control(port
,
164 PARPORT_CONTROL_SELECT
|
165 PARPORT_CONTROL_INIT
);
174 /* Forget about devices on a physical port. */
175 void parport_daisy_fini(struct parport
*port
)
179 spin_lock(&topology_lock
);
182 struct daisydev
*dev
= *p
;
183 if (dev
->port
!= port
) {
191 /* Gaps in the numbering could be handled better. How should
192 someone enumerate through all IEEE1284.3 devices in the
194 if (!topology
) numdevs
= 0;
195 spin_unlock(&topology_lock
);
200 * parport_open - find a device by canonical device number
201 * @devnum: canonical device number
202 * @name: name to associate with the device
204 * This function is similar to parport_register_device(), except
205 * that it locates a device by its number rather than by the port
208 * All parameters except for @devnum are the same as for
209 * parport_register_device(). The return value is the same as
210 * for parport_register_device().
213 struct pardevice
*parport_open(int devnum
, const char *name
)
215 struct daisydev
*p
= topology
;
216 struct parport
*port
;
217 struct pardevice
*dev
;
220 spin_lock(&topology_lock
);
221 while (p
&& p
->devnum
!= devnum
)
225 spin_unlock(&topology_lock
);
230 port
= parport_get_port(p
->port
);
231 spin_unlock(&topology_lock
);
233 dev
= parport_register_device(port
, name
, NULL
, NULL
, NULL
, 0, NULL
);
234 parport_put_port(port
);
240 /* Check that there really is a device to select. */
243 parport_claim_or_block(dev
);
244 selected
= port
->daisy
;
245 parport_release(dev
);
247 if (selected
!= daisy
) {
248 /* No corresponding device. */
249 parport_unregister_device(dev
);
258 * parport_close - close a device opened with parport_open()
259 * @dev: device to close
261 * This is to parport_open() as parport_unregister_device() is to
262 * parport_register_device().
265 void parport_close(struct pardevice
*dev
)
267 parport_unregister_device(dev
);
270 /* Send a daisy-chain-style CPP command packet. */
271 static int cpp_daisy(struct parport
*port
, int cmd
)
275 parport_data_forward(port
);
276 parport_write_data(port
, 0xaa); udelay(2);
277 parport_write_data(port
, 0x55); udelay(2);
278 parport_write_data(port
, 0x00); udelay(2);
279 parport_write_data(port
, 0xff); udelay(2);
280 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
281 | PARPORT_STATUS_PAPEROUT
282 | PARPORT_STATUS_SELECT
283 | PARPORT_STATUS_ERROR
);
284 if (s
!= (PARPORT_STATUS_BUSY
285 | PARPORT_STATUS_PAPEROUT
286 | PARPORT_STATUS_SELECT
287 | PARPORT_STATUS_ERROR
)) {
288 DPRINTK(KERN_DEBUG
"%s: cpp_daisy: aa5500ff(%02x)\n",
293 parport_write_data(port
, 0x87); udelay(2);
294 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
295 | PARPORT_STATUS_PAPEROUT
296 | PARPORT_STATUS_SELECT
297 | PARPORT_STATUS_ERROR
);
298 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
299 DPRINTK(KERN_DEBUG
"%s: cpp_daisy: aa5500ff87(%02x)\n",
304 parport_write_data(port
, 0x78); udelay(2);
305 parport_write_data(port
, cmd
); udelay(2);
306 parport_frob_control(port
,
307 PARPORT_CONTROL_STROBE
,
308 PARPORT_CONTROL_STROBE
);
310 s
= parport_read_status(port
);
311 parport_frob_control(port
, PARPORT_CONTROL_STROBE
, 0);
313 parport_write_data(port
, 0xff); udelay(2);
318 /* Send a mux-style CPP command packet. */
319 static int cpp_mux(struct parport
*port
, int cmd
)
324 parport_data_forward(port
);
325 parport_write_data(port
, 0xaa); udelay(2);
326 parport_write_data(port
, 0x55); udelay(2);
327 parport_write_data(port
, 0xf0); udelay(2);
328 parport_write_data(port
, 0x0f); udelay(2);
329 parport_write_data(port
, 0x52); udelay(2);
330 parport_write_data(port
, 0xad); udelay(2);
331 parport_write_data(port
, cmd
); udelay(2);
333 s
= parport_read_status(port
);
334 if (!(s
& PARPORT_STATUS_ACK
)) {
335 DPRINTK(KERN_DEBUG
"%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
340 rc
= (((s
& PARPORT_STATUS_SELECT
? 1 : 0) << 0) |
341 ((s
& PARPORT_STATUS_PAPEROUT
? 1 : 0) << 1) |
342 ((s
& PARPORT_STATUS_BUSY
? 0 : 1) << 2) |
343 ((s
& PARPORT_STATUS_ERROR
? 0 : 1) << 3));
348 void parport_daisy_deselect_all(struct parport
*port
)
350 cpp_daisy(port
, 0x30);
353 int parport_daisy_select(struct parport
*port
, int daisy
, int mode
)
357 // For these modes we should switch to EPP mode:
358 case IEEE1284_MODE_EPP
:
359 case IEEE1284_MODE_EPPSL
:
360 case IEEE1284_MODE_EPPSWE
:
361 return !(cpp_daisy(port
, 0x20 + daisy
) &
362 PARPORT_STATUS_ERROR
);
364 // For these modes we should switch to ECP mode:
365 case IEEE1284_MODE_ECP
:
366 case IEEE1284_MODE_ECPRLE
:
367 case IEEE1284_MODE_ECPSWE
:
368 return !(cpp_daisy(port
, 0xd0 + daisy
) &
369 PARPORT_STATUS_ERROR
);
371 // Nothing was told for BECP in Daisy chain specification.
372 // May be it's wise to use ECP?
373 case IEEE1284_MODE_BECP
:
374 // Others use compat mode
375 case IEEE1284_MODE_NIBBLE
:
376 case IEEE1284_MODE_BYTE
:
377 case IEEE1284_MODE_COMPAT
:
379 return !(cpp_daisy(port
, 0xe0 + daisy
) &
380 PARPORT_STATUS_ERROR
);
384 static int mux_present(struct parport
*port
)
386 return cpp_mux(port
, 0x51) == 3;
389 static int num_mux_ports(struct parport
*port
)
391 return cpp_mux(port
, 0x58);
394 static int select_port(struct parport
*port
)
396 int muxport
= port
->muxport
;
397 return cpp_mux(port
, 0x60 + muxport
) == muxport
;
400 static int assign_addrs(struct parport
*port
)
404 int thisdev
= numdevs
;
408 parport_data_forward(port
);
409 parport_write_data(port
, 0xaa); udelay(2);
410 parport_write_data(port
, 0x55); udelay(2);
411 parport_write_data(port
, 0x00); udelay(2);
412 parport_write_data(port
, 0xff); udelay(2);
413 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
414 | PARPORT_STATUS_PAPEROUT
415 | PARPORT_STATUS_SELECT
416 | PARPORT_STATUS_ERROR
);
417 if (s
!= (PARPORT_STATUS_BUSY
418 | PARPORT_STATUS_PAPEROUT
419 | PARPORT_STATUS_SELECT
420 | PARPORT_STATUS_ERROR
)) {
421 DPRINTK(KERN_DEBUG
"%s: assign_addrs: aa5500ff(%02x)\n",
426 parport_write_data(port
, 0x87); udelay(2);
427 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
428 | PARPORT_STATUS_PAPEROUT
429 | PARPORT_STATUS_SELECT
430 | PARPORT_STATUS_ERROR
);
431 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
432 DPRINTK(KERN_DEBUG
"%s: assign_addrs: aa5500ff87(%02x)\n",
437 parport_write_data(port
, 0x78); udelay(2);
438 s
= parport_read_status(port
);
441 (s
& (PARPORT_STATUS_PAPEROUT
|PARPORT_STATUS_SELECT
))
442 == (PARPORT_STATUS_PAPEROUT
|PARPORT_STATUS_SELECT
)
445 parport_write_data(port
, daisy
);
447 parport_frob_control(port
,
448 PARPORT_CONTROL_STROBE
,
449 PARPORT_CONTROL_STROBE
);
451 parport_frob_control(port
, PARPORT_CONTROL_STROBE
, 0);
454 add_dev(numdevs
++, port
, daisy
);
456 /* See if this device thought it was the last in the
458 if (!(s
& PARPORT_STATUS_BUSY
))
461 /* We are seeing pass through status now. We see
462 last_dev from next device or if last_dev does not
463 work status lines from some non-daisy chain
465 s
= parport_read_status(port
);
468 parport_write_data(port
, 0xff); udelay(2);
469 detected
= numdevs
- thisdev
;
470 DPRINTK(KERN_DEBUG
"%s: Found %d daisy-chained devices\n", port
->name
,
473 /* Ask the new devices to introduce themselves. */
474 deviceid
= kmalloc(1024, GFP_KERNEL
);
475 if (!deviceid
) return 0;
477 for (daisy
= 0; thisdev
< numdevs
; thisdev
++, daisy
++)
478 parport_device_id(thisdev
, deviceid
, 1024);
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