blob: 3c8f06c3a5a07acc4c1f041fee7c495a2386c53e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Matthew Martind32ccc42006-10-03 23:25:14 +020033#define DPRINTK(stuff...) printk(stuff)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#else
35#define DPRINTK(stuff...)
36#endif
37
38static struct daisydev {
39 struct daisydev *next;
40 struct parport *port;
41 int daisy;
42 int devnum;
43} *topology = NULL;
44static DEFINE_SPINLOCK(topology_lock);
45
46static int numdevs = 0;
47
48/* Forward-declaration of lower-level functions. */
Matthew Martind32ccc42006-10-03 23:25:14 +020049static int mux_present(struct parport *port);
50static int num_mux_ports(struct parport *port);
51static int select_port(struct parport *port);
52static int assign_addrs(struct parport *port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54/* Add a device to the discovered topology. */
Matthew Martind32ccc42006-10-03 23:25:14 +020055static void add_dev(int devnum, struct parport *port, int daisy)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
57 struct daisydev *newdev, **p;
Matthew Martind32ccc42006-10-03 23:25:14 +020058 newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 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). */
Matthew Martind32ccc42006-10-03 23:25:14 +020073static struct parport *clone_parport(struct parport *real, int muxport)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074{
Matthew Martind32ccc42006-10-03 23:25:14 +020075 struct parport *extra = parport_register_port(real->base,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 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. */
Matthew Martind32ccc42006-10-03 23:25:14 +020091int parport_daisy_init(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092{
93 int detected = 0;
94 char *deviceid;
95 static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
96 int num_ports;
97 int i;
98 int last_try = 0;
99
100again:
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. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200106 if (port->muxport < 0 && mux_present(port) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 /* don't be fooled: a mux must have 2 or 4 ports. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200108 ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 /* Leave original as port zero. */
110 port->muxport = 0;
Matthew Martind32ccc42006-10-03 23:25:14 +0200111 printk(KERN_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 "%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. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200116 struct parport *extra = clone_parport(port, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 if (!extra) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200118 if (signal_pending(current))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 break;
120
Matthew Martind32ccc42006-10-03 23:25:14 +0200121 schedule();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 continue;
123 }
124
Matthew Martind32ccc42006-10-03 23:25:14 +0200125 printk(KERN_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 "%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)
Matthew Martind32ccc42006-10-03 23:25:14 +0200138 select_port(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Matthew Martind32ccc42006-10-03 23:25:14 +0200140 parport_daisy_deselect_all(port);
141 detected += assign_addrs(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 /* Count the potential legacy device at the end. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200144 add_dev(numdevs++, port, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146 /* Find out the legacy device's IEEE 1284 device ID. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200147 deviceid = kmalloc(1024, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 if (deviceid) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200149 if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 detected++;
151
Matthew Martind32ccc42006-10-03 23:25:14 +0200152 kfree(deviceid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 }
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. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200159 parport_daisy_fini(port);
160 parport_write_control(port, PARPORT_CONTROL_SELECT);
161 udelay(50);
162 parport_write_control(port,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 PARPORT_CONTROL_SELECT |
164 PARPORT_CONTROL_INIT);
Matthew Martind32ccc42006-10-03 23:25:14 +0200165 udelay(50);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 last_try = 1;
167 goto again;
168 }
169
170 return detected;
171}
172
173/* Forget about devices on a physical port. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200174void parport_daisy_fini(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 *
203 * This function is similar to parport_register_device(), except
204 * that it locates a device by its number rather than by the port
205 * it is attached to.
206 *
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().
210 **/
211
Jeff Garzik5712cb32007-10-19 02:54:26 -0400212struct pardevice *parport_open(int devnum, const char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
214 struct daisydev *p = topology;
215 struct parport *port;
216 struct pardevice *dev;
217 int daisy;
218
219 spin_lock(&topology_lock);
220 while (p && p->devnum != devnum)
221 p = p->next;
222
223 if (!p) {
224 spin_unlock(&topology_lock);
225 return NULL;
226 }
227
228 daisy = p->daisy;
229 port = parport_get_port(p->port);
230 spin_unlock(&topology_lock);
231
Jeff Garzik5712cb32007-10-19 02:54:26 -0400232 dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 parport_put_port(port);
234 if (!dev)
235 return NULL;
236
237 dev->daisy = daisy;
238
239 /* Check that there really is a device to select. */
240 if (daisy >= 0) {
241 int selected;
Matthew Martind32ccc42006-10-03 23:25:14 +0200242 parport_claim_or_block(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 selected = port->daisy;
Matthew Martind32ccc42006-10-03 23:25:14 +0200244 parport_release(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Marko Kohtalac29a75e2006-01-06 00:19:46 -0800246 if (selected != daisy) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 /* No corresponding device. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200248 parport_unregister_device(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 return NULL;
250 }
251 }
252
253 return dev;
254}
255
256/**
257 * parport_close - close a device opened with parport_open()
258 * @dev: device to close
259 *
260 * This is to parport_open() as parport_unregister_device() is to
261 * parport_register_device().
262 **/
263
Matthew Martind32ccc42006-10-03 23:25:14 +0200264void parport_close(struct pardevice *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265{
Matthew Martind32ccc42006-10-03 23:25:14 +0200266 parport_unregister_device(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267}
268
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269/* Send a daisy-chain-style CPP command packet. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200270static int cpp_daisy(struct parport *port, int cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
272 unsigned char s;
273
Matthew Martind32ccc42006-10-03 23:25:14 +0200274 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 | 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)) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200287 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 port->name, s);
289 return -ENXIO;
290 }
291
Matthew Martind32ccc42006-10-03 23:25:14 +0200292 parport_write_data(port, 0x87); udelay(2);
293 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 | PARPORT_STATUS_PAPEROUT
295 | PARPORT_STATUS_SELECT
296 | PARPORT_STATUS_ERROR);
297 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200298 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 port->name, s);
300 return -ENXIO;
301 }
302
Matthew Martind32ccc42006-10-03 23:25:14 +0200303 parport_write_data(port, 0x78); udelay(2);
304 parport_write_data(port, cmd); udelay(2);
305 parport_frob_control(port,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 PARPORT_CONTROL_STROBE,
307 PARPORT_CONTROL_STROBE);
Matthew Martind32ccc42006-10-03 23:25:14 +0200308 udelay(1);
309 s = parport_read_status(port);
310 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
311 udelay(1);
312 parport_write_data(port, 0xff); udelay(2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
314 return s;
315}
316
317/* Send a mux-style CPP command packet. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200318static int cpp_mux(struct parport *port, int cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319{
320 unsigned char s;
321 int rc;
322
Matthew Martind32ccc42006-10-03 23:25:14 +0200323 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Matthew Martind32ccc42006-10-03 23:25:14 +0200332 s = parport_read_status(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 if (!(s & PARPORT_STATUS_ACK)) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200334 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 port->name, cmd, s);
336 return -EIO;
337 }
338
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));
343
344 return rc;
345}
346
Matthew Martind32ccc42006-10-03 23:25:14 +0200347void parport_daisy_deselect_all(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348{
Matthew Martind32ccc42006-10-03 23:25:14 +0200349 cpp_daisy(port, 0x30);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351
Matthew Martind32ccc42006-10-03 23:25:14 +0200352int parport_daisy_select(struct parport *port, int daisy, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
354 switch (mode)
355 {
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:
Matthew Martind32ccc42006-10-03 23:25:14 +0200360 return !(cpp_daisy(port, 0x20 + daisy) &
Marko Kohtala7c9cc3b2006-01-06 00:19:46 -0800361 PARPORT_STATUS_ERROR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
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:
Matthew Martind32ccc42006-10-03 23:25:14 +0200367 return !(cpp_daisy(port, 0xd0 + daisy) &
Marko Kohtala7c9cc3b2006-01-06 00:19:46 -0800368 PARPORT_STATUS_ERROR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
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:
377 default:
Matthew Martind32ccc42006-10-03 23:25:14 +0200378 return !(cpp_daisy(port, 0xe0 + daisy) &
Marko Kohtala7c9cc3b2006-01-06 00:19:46 -0800379 PARPORT_STATUS_ERROR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 }
381}
382
Matthew Martind32ccc42006-10-03 23:25:14 +0200383static int mux_present(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384{
Matthew Martind32ccc42006-10-03 23:25:14 +0200385 return cpp_mux(port, 0x51) == 3;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386}
387
Matthew Martind32ccc42006-10-03 23:25:14 +0200388static int num_mux_ports(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389{
Matthew Martind32ccc42006-10-03 23:25:14 +0200390 return cpp_mux(port, 0x58);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391}
392
Matthew Martind32ccc42006-10-03 23:25:14 +0200393static int select_port(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394{
395 int muxport = port->muxport;
Matthew Martind32ccc42006-10-03 23:25:14 +0200396 return cpp_mux(port, 0x60 + muxport) == muxport;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397}
398
Matthew Martind32ccc42006-10-03 23:25:14 +0200399static int assign_addrs(struct parport *port)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400{
Marko Kohtala310c8c32006-01-06 00:19:45 -0800401 unsigned char s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 unsigned char daisy;
403 int thisdev = numdevs;
404 int detected;
405 char *deviceid;
406
Matthew Martind32ccc42006-10-03 23:25:14 +0200407 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 | 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)) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200420 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 port->name, s);
422 return 0;
423 }
424
Matthew Martind32ccc42006-10-03 23:25:14 +0200425 parport_write_data(port, 0x87); udelay(2);
426 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 | PARPORT_STATUS_PAPEROUT
428 | PARPORT_STATUS_SELECT
429 | PARPORT_STATUS_ERROR);
430 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200431 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 port->name, s);
433 return 0;
434 }
435
Matthew Martind32ccc42006-10-03 23:25:14 +0200436 parport_write_data(port, 0x78); udelay(2);
437 s = parport_read_status(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
Marko Kohtala310c8c32006-01-06 00:19:45 -0800439 for (daisy = 0;
440 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT))
441 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)
442 && daisy < 4;
443 ++daisy) {
Matthew Martind32ccc42006-10-03 23:25:14 +0200444 parport_write_data(port, daisy);
445 udelay(2);
446 parport_frob_control(port,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 PARPORT_CONTROL_STROBE,
448 PARPORT_CONTROL_STROBE);
Matthew Martind32ccc42006-10-03 23:25:14 +0200449 udelay(1);
450 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
451 udelay(1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
Matthew Martind32ccc42006-10-03 23:25:14 +0200453 add_dev(numdevs++, port, daisy);
Marko Kohtala310c8c32006-01-06 00:19:45 -0800454
455 /* See if this device thought it was the last in the
456 * chain. */
457 if (!(s & PARPORT_STATUS_BUSY))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 break;
459
Marko Kohtala310c8c32006-01-06 00:19:45 -0800460 /* 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
463 device. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200464 s = parport_read_status(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 }
466
Matthew Martind32ccc42006-10-03 23:25:14 +0200467 parport_write_data(port, 0xff); udelay(2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 detected = numdevs - thisdev;
Matthew Martind32ccc42006-10-03 23:25:14 +0200469 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 detected);
471
472 /* Ask the new devices to introduce themselves. */
Matthew Martind32ccc42006-10-03 23:25:14 +0200473 deviceid = kmalloc(1024, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 if (!deviceid) return 0;
475
476 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
Matthew Martind32ccc42006-10-03 23:25:14 +0200477 parport_device_id(thisdev, deviceid, 1024);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Matthew Martind32ccc42006-10-03 23:25:14 +0200479 kfree(deviceid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 return detected;
481}