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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/parport/daisy.c
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/sched.h>
27 #include <asm/current.h>
28 #include <asm/uaccess.h>
33 #define DPRINTK(stuff...) printk(stuff)
35 #define DPRINTK(stuff...)
38 static struct daisydev
{
39 struct daisydev
*next
;
44 static DEFINE_SPINLOCK(topology_lock
);
46 static int numdevs
= 0;
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
);
54 /* Add a device to the discovered topology. */
55 static void add_dev(int devnum
, struct parport
*port
, int daisy
)
57 struct daisydev
*newdev
, **p
;
58 newdev
= kmalloc(sizeof(struct daisydev
), GFP_KERNEL
);
61 newdev
->daisy
= daisy
;
62 newdev
->devnum
= devnum
;
63 spin_lock(&topology_lock
);
64 for (p
= &topology
; *p
&& (*p
)->devnum
<devnum
; p
= &(*p
)->next
)
68 spin_unlock(&topology_lock
);
72 /* Clone a parport (actually, make an alias). */
73 static struct parport
*clone_parport(struct parport
*real
, int muxport
)
75 struct parport
*extra
= parport_register_port(real
->base
,
80 extra
->portnum
= real
->portnum
;
81 extra
->physport
= real
;
82 extra
->muxport
= muxport
;
83 real
->slaves
[muxport
-1] = extra
;
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
)
95 static const char *th
[] = { /*0*/"th", "st", "nd", "rd", "th" };
101 /* Because this is called before any other devices exist,
102 * we don't have to claim exclusive access. */
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. */
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
);
118 if (signal_pending(current
))
126 "%s: %d%s port of %d-way multiplexor on %s\n",
127 extra
->name
, i
+ 1, th
[i
+ 1], num_ports
,
130 /* Analyse that port too. We won't recurse
131 forever because of the 'port->muxport < 0'
133 parport_daisy_init(extra
);
137 if (port
->muxport
>= 0)
140 parport_daisy_deselect_all(port
);
141 detected
+= assign_addrs(port
);
143 /* Count the potential legacy device at the end. */
144 add_dev(numdevs
++, port
, -1);
146 /* Find out the legacy device's IEEE 1284 device ID. */
147 deviceid
= kmalloc(1024, GFP_KERNEL
);
149 if (parport_device_id(numdevs
- 1, deviceid
, 1024) > 2)
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
159 parport_daisy_fini(port
);
160 parport_write_control(port
, PARPORT_CONTROL_SELECT
);
162 parport_write_control(port
,
163 PARPORT_CONTROL_SELECT
|
164 PARPORT_CONTROL_INIT
);
173 /* Forget about devices on a physical port. */
174 void parport_daisy_fini(struct parport
*port
)
178 spin_lock(&topology_lock
);
181 struct daisydev
*dev
= *p
;
182 if (dev
->port
!= port
) {
190 /* Gaps in the numbering could be handled better. How should
191 someone enumerate through all IEEE1284.3 devices in the
193 if (!topology
) numdevs
= 0;
194 spin_unlock(&topology_lock
);
199 * parport_open - find a device by canonical device number
200 * @devnum: canonical device number
201 * @name: name to associate with the device
203 * This function is similar to parport_register_device(), except
204 * that it locates a device by its number rather than by the port
207 * All parameters except for @devnum are the same as for
208 * parport_register_device(). The return value is the same as
209 * for parport_register_device().
212 struct pardevice
*parport_open(int devnum
, const char *name
)
214 struct daisydev
*p
= topology
;
215 struct parport
*port
;
216 struct pardevice
*dev
;
219 spin_lock(&topology_lock
);
220 while (p
&& p
->devnum
!= devnum
)
224 spin_unlock(&topology_lock
);
229 port
= parport_get_port(p
->port
);
230 spin_unlock(&topology_lock
);
232 dev
= parport_register_device(port
, name
, NULL
, NULL
, NULL
, 0, NULL
);
233 parport_put_port(port
);
239 /* Check that there really is a device to select. */
242 parport_claim_or_block(dev
);
243 selected
= port
->daisy
;
244 parport_release(dev
);
246 if (selected
!= daisy
) {
247 /* No corresponding device. */
248 parport_unregister_device(dev
);
257 * parport_close - close a device opened with parport_open()
258 * @dev: device to close
260 * This is to parport_open() as parport_unregister_device() is to
261 * parport_register_device().
264 void parport_close(struct pardevice
*dev
)
266 parport_unregister_device(dev
);
269 /* Send a daisy-chain-style CPP command packet. */
270 static int cpp_daisy(struct parport
*port
, int cmd
)
274 parport_data_forward(port
);
275 parport_write_data(port
, 0xaa); udelay(2);
276 parport_write_data(port
, 0x55); udelay(2);
277 parport_write_data(port
, 0x00); udelay(2);
278 parport_write_data(port
, 0xff); udelay(2);
279 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
280 | PARPORT_STATUS_PAPEROUT
281 | PARPORT_STATUS_SELECT
282 | PARPORT_STATUS_ERROR
);
283 if (s
!= (PARPORT_STATUS_BUSY
284 | PARPORT_STATUS_PAPEROUT
285 | PARPORT_STATUS_SELECT
286 | PARPORT_STATUS_ERROR
)) {
287 DPRINTK(KERN_DEBUG
"%s: cpp_daisy: aa5500ff(%02x)\n",
292 parport_write_data(port
, 0x87); udelay(2);
293 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
294 | PARPORT_STATUS_PAPEROUT
295 | PARPORT_STATUS_SELECT
296 | PARPORT_STATUS_ERROR
);
297 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
298 DPRINTK(KERN_DEBUG
"%s: cpp_daisy: aa5500ff87(%02x)\n",
303 parport_write_data(port
, 0x78); udelay(2);
304 parport_write_data(port
, cmd
); udelay(2);
305 parport_frob_control(port
,
306 PARPORT_CONTROL_STROBE
,
307 PARPORT_CONTROL_STROBE
);
309 s
= parport_read_status(port
);
310 parport_frob_control(port
, PARPORT_CONTROL_STROBE
, 0);
312 parport_write_data(port
, 0xff); udelay(2);
317 /* Send a mux-style CPP command packet. */
318 static int cpp_mux(struct parport
*port
, int cmd
)
323 parport_data_forward(port
);
324 parport_write_data(port
, 0xaa); udelay(2);
325 parport_write_data(port
, 0x55); udelay(2);
326 parport_write_data(port
, 0xf0); udelay(2);
327 parport_write_data(port
, 0x0f); udelay(2);
328 parport_write_data(port
, 0x52); udelay(2);
329 parport_write_data(port
, 0xad); udelay(2);
330 parport_write_data(port
, cmd
); udelay(2);
332 s
= parport_read_status(port
);
333 if (!(s
& PARPORT_STATUS_ACK
)) {
334 DPRINTK(KERN_DEBUG
"%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
339 rc
= (((s
& PARPORT_STATUS_SELECT
? 1 : 0) << 0) |
340 ((s
& PARPORT_STATUS_PAPEROUT
? 1 : 0) << 1) |
341 ((s
& PARPORT_STATUS_BUSY
? 0 : 1) << 2) |
342 ((s
& PARPORT_STATUS_ERROR
? 0 : 1) << 3));
347 void parport_daisy_deselect_all(struct parport
*port
)
349 cpp_daisy(port
, 0x30);
352 int parport_daisy_select(struct parport
*port
, int daisy
, int mode
)
356 // For these modes we should switch to EPP mode:
357 case IEEE1284_MODE_EPP
:
358 case IEEE1284_MODE_EPPSL
:
359 case IEEE1284_MODE_EPPSWE
:
360 return !(cpp_daisy(port
, 0x20 + daisy
) &
361 PARPORT_STATUS_ERROR
);
363 // For these modes we should switch to ECP mode:
364 case IEEE1284_MODE_ECP
:
365 case IEEE1284_MODE_ECPRLE
:
366 case IEEE1284_MODE_ECPSWE
:
367 return !(cpp_daisy(port
, 0xd0 + daisy
) &
368 PARPORT_STATUS_ERROR
);
370 // Nothing was told for BECP in Daisy chain specification.
371 // May be it's wise to use ECP?
372 case IEEE1284_MODE_BECP
:
373 // Others use compat mode
374 case IEEE1284_MODE_NIBBLE
:
375 case IEEE1284_MODE_BYTE
:
376 case IEEE1284_MODE_COMPAT
:
378 return !(cpp_daisy(port
, 0xe0 + daisy
) &
379 PARPORT_STATUS_ERROR
);
383 static int mux_present(struct parport
*port
)
385 return cpp_mux(port
, 0x51) == 3;
388 static int num_mux_ports(struct parport
*port
)
390 return cpp_mux(port
, 0x58);
393 static int select_port(struct parport
*port
)
395 int muxport
= port
->muxport
;
396 return cpp_mux(port
, 0x60 + muxport
) == muxport
;
399 static int assign_addrs(struct parport
*port
)
403 int thisdev
= numdevs
;
407 parport_data_forward(port
);
408 parport_write_data(port
, 0xaa); udelay(2);
409 parport_write_data(port
, 0x55); udelay(2);
410 parport_write_data(port
, 0x00); udelay(2);
411 parport_write_data(port
, 0xff); udelay(2);
412 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
413 | PARPORT_STATUS_PAPEROUT
414 | PARPORT_STATUS_SELECT
415 | PARPORT_STATUS_ERROR
);
416 if (s
!= (PARPORT_STATUS_BUSY
417 | PARPORT_STATUS_PAPEROUT
418 | PARPORT_STATUS_SELECT
419 | PARPORT_STATUS_ERROR
)) {
420 DPRINTK(KERN_DEBUG
"%s: assign_addrs: aa5500ff(%02x)\n",
425 parport_write_data(port
, 0x87); udelay(2);
426 s
= parport_read_status(port
) & (PARPORT_STATUS_BUSY
427 | PARPORT_STATUS_PAPEROUT
428 | PARPORT_STATUS_SELECT
429 | PARPORT_STATUS_ERROR
);
430 if (s
!= (PARPORT_STATUS_SELECT
| PARPORT_STATUS_ERROR
)) {
431 DPRINTK(KERN_DEBUG
"%s: assign_addrs: aa5500ff87(%02x)\n",
436 parport_write_data(port
, 0x78); udelay(2);
437 s
= parport_read_status(port
);
440 (s
& (PARPORT_STATUS_PAPEROUT
|PARPORT_STATUS_SELECT
))
441 == (PARPORT_STATUS_PAPEROUT
|PARPORT_STATUS_SELECT
)
444 parport_write_data(port
, daisy
);
446 parport_frob_control(port
,
447 PARPORT_CONTROL_STROBE
,
448 PARPORT_CONTROL_STROBE
);
450 parport_frob_control(port
, PARPORT_CONTROL_STROBE
, 0);
453 add_dev(numdevs
++, port
, daisy
);
455 /* See if this device thought it was the last in the
457 if (!(s
& PARPORT_STATUS_BUSY
))
460 /* We are seeing pass through status now. We see
461 last_dev from next device or if last_dev does not
462 work status lines from some non-daisy chain
464 s
= parport_read_status(port
);
467 parport_write_data(port
, 0xff); udelay(2);
468 detected
= numdevs
- thisdev
;
469 DPRINTK(KERN_DEBUG
"%s: Found %d daisy-chained devices\n", port
->name
,
472 /* Ask the new devices to introduce themselves. */
473 deviceid
= kmalloc(1024, GFP_KERNEL
);
474 if (!deviceid
) return 0;
476 for (daisy
= 0; thisdev
< numdevs
; thisdev
++, daisy
++)
477 parport_device_id(thisdev
, deviceid
, 1024);