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/signal.h>
28 #include <asm/current.h>
29 #include <linux/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);
48 static bool daisy_init_done;
50 /* Forward-declaration of lower-level functions. */
51 static int mux_present(struct parport *port);
52 static int num_mux_ports(struct parport *port);
53 static int select_port(struct parport *port);
54 static int assign_addrs(struct parport *port);
56 /* Add a device to the discovered topology. */
57 static void add_dev(int devnum, struct parport *port, int daisy)
59 struct daisydev *newdev, **p;
60 newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL);
63 newdev->daisy = daisy;
64 newdev->devnum = devnum;
65 spin_lock(&topology_lock);
66 for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next)
70 spin_unlock(&topology_lock);
74 /* Clone a parport (actually, make an alias). */
75 static struct parport *clone_parport(struct parport *real, int muxport)
77 struct parport *extra = parport_register_port(real->base,
82 extra->portnum = real->portnum;
83 extra->physport = real;
84 extra->muxport = muxport;
85 real->slaves[muxport-1] = extra;
91 static int daisy_drv_probe(struct pardevice *par_dev)
93 struct device_driver *drv = par_dev->dev.driver;
95 if (strcmp(drv->name, "daisy_drv"))
97 if (strcmp(par_dev->name, daisy_dev_name))
103 static struct parport_driver daisy_driver = {
105 .probe = daisy_drv_probe,
109 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
110 * Return value is number of devices actually detected. */
111 int parport_daisy_init(struct parport *port)
115 static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
120 if (!daisy_init_done) {
122 * flag should be marked true first as
123 * parport_register_driver() might try to load the low
124 * level driver which will lead to announcing new ports
125 * and which will again come back here at
126 * parport_daisy_init()
128 daisy_init_done = true;
129 i = parport_register_driver(&daisy_driver);
131 pr_err("daisy registration failed\n");
132 daisy_init_done = false;
138 /* Because this is called before any other devices exist,
139 * we don't have to claim exclusive access. */
141 /* If mux present on normal port, need to create new
142 * parports for each extra port. */
143 if (port->muxport < 0 && mux_present(port) &&
144 /* don't be fooled: a mux must have 2 or 4 ports. */
145 ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {
146 /* Leave original as port zero. */
148 pr_info("%s: 1st (default) port of %d-way multiplexor\n",
149 port->name, num_ports);
150 for (i = 1; i < num_ports; i++) {
151 /* Clone the port. */
152 struct parport *extra = clone_parport(port, i);
154 if (signal_pending(current))
161 pr_info("%s: %d%s port of %d-way multiplexor on %s\n",
162 extra->name, i + 1, th[i + 1], num_ports,
165 /* Analyse that port too. We won't recurse
166 forever because of the 'port->muxport < 0'
168 parport_daisy_init(extra);
172 if (port->muxport >= 0)
175 parport_daisy_deselect_all(port);
176 detected += assign_addrs(port);
178 /* Count the potential legacy device at the end. */
179 add_dev(numdevs++, port, -1);
181 /* Find out the legacy device's IEEE 1284 device ID. */
182 deviceid = kmalloc(1024, GFP_KERNEL);
184 if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
190 if (!detected && !last_try) {
191 /* No devices were detected. Perhaps they are in some
192 funny state; let's try to reset them and see if
194 parport_daisy_fini(port);
195 parport_write_control(port, PARPORT_CONTROL_SELECT);
197 parport_write_control(port,
198 PARPORT_CONTROL_SELECT |
199 PARPORT_CONTROL_INIT);
208 /* Forget about devices on a physical port. */
209 void parport_daisy_fini(struct parport *port)
213 spin_lock(&topology_lock);
216 struct daisydev *dev = *p;
217 if (dev->port != port) {
225 /* Gaps in the numbering could be handled better. How should
226 someone enumerate through all IEEE1284.3 devices in the
228 if (!topology) numdevs = 0;
229 spin_unlock(&topology_lock);
234 * parport_open - find a device by canonical device number
235 * @devnum: canonical device number
236 * @name: name to associate with the device
238 * This function is similar to parport_register_device(), except
239 * that it locates a device by its number rather than by the port
242 * All parameters except for @devnum are the same as for
243 * parport_register_device(). The return value is the same as
244 * for parport_register_device().
247 struct pardevice *parport_open(int devnum, const char *name)
249 struct daisydev *p = topology;
250 struct pardev_cb par_cb;
251 struct parport *port;
252 struct pardevice *dev;
255 memset(&par_cb, 0, sizeof(par_cb));
256 spin_lock(&topology_lock);
257 while (p && p->devnum != devnum)
261 spin_unlock(&topology_lock);
266 port = parport_get_port(p->port);
267 spin_unlock(&topology_lock);
269 dev = parport_register_dev_model(port, name, &par_cb, devnum);
270 parport_put_port(port);
276 /* Check that there really is a device to select. */
279 parport_claim_or_block(dev);
280 selected = port->daisy;
281 parport_release(dev);
283 if (selected != daisy) {
284 /* No corresponding device. */
285 parport_unregister_device(dev);
294 * parport_close - close a device opened with parport_open()
295 * @dev: device to close
297 * This is to parport_open() as parport_unregister_device() is to
298 * parport_register_device().
301 void parport_close(struct pardevice *dev)
303 parport_unregister_device(dev);
306 /* Send a daisy-chain-style CPP command packet. */
307 static int cpp_daisy(struct parport *port, int cmd)
311 parport_data_forward(port);
312 parport_write_data(port, 0xaa); udelay(2);
313 parport_write_data(port, 0x55); udelay(2);
314 parport_write_data(port, 0x00); udelay(2);
315 parport_write_data(port, 0xff); udelay(2);
316 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
317 | PARPORT_STATUS_PAPEROUT
318 | PARPORT_STATUS_SELECT
319 | PARPORT_STATUS_ERROR);
320 if (s != (PARPORT_STATUS_BUSY
321 | PARPORT_STATUS_PAPEROUT
322 | PARPORT_STATUS_SELECT
323 | PARPORT_STATUS_ERROR)) {
324 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
329 parport_write_data(port, 0x87); udelay(2);
330 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
331 | PARPORT_STATUS_PAPEROUT
332 | PARPORT_STATUS_SELECT
333 | PARPORT_STATUS_ERROR);
334 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
335 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
340 parport_write_data(port, 0x78); udelay(2);
341 parport_write_data(port, cmd); udelay(2);
342 parport_frob_control(port,
343 PARPORT_CONTROL_STROBE,
344 PARPORT_CONTROL_STROBE);
346 s = parport_read_status(port);
347 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
349 parport_write_data(port, 0xff); udelay(2);
354 /* Send a mux-style CPP command packet. */
355 static int cpp_mux(struct parport *port, int cmd)
360 parport_data_forward(port);
361 parport_write_data(port, 0xaa); udelay(2);
362 parport_write_data(port, 0x55); udelay(2);
363 parport_write_data(port, 0xf0); udelay(2);
364 parport_write_data(port, 0x0f); udelay(2);
365 parport_write_data(port, 0x52); udelay(2);
366 parport_write_data(port, 0xad); udelay(2);
367 parport_write_data(port, cmd); udelay(2);
369 s = parport_read_status(port);
370 if (!(s & PARPORT_STATUS_ACK)) {
371 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
376 rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) |
377 ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
378 ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) |
379 ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3));
384 void parport_daisy_deselect_all(struct parport *port)
386 cpp_daisy(port, 0x30);
389 int parport_daisy_select(struct parport *port, int daisy, int mode)
393 // For these modes we should switch to EPP mode:
394 case IEEE1284_MODE_EPP:
395 case IEEE1284_MODE_EPPSL:
396 case IEEE1284_MODE_EPPSWE:
397 return !(cpp_daisy(port, 0x20 + daisy) &
398 PARPORT_STATUS_ERROR);
400 // For these modes we should switch to ECP mode:
401 case IEEE1284_MODE_ECP:
402 case IEEE1284_MODE_ECPRLE:
403 case IEEE1284_MODE_ECPSWE:
404 return !(cpp_daisy(port, 0xd0 + daisy) &
405 PARPORT_STATUS_ERROR);
407 // Nothing was told for BECP in Daisy chain specification.
408 // May be it's wise to use ECP?
409 case IEEE1284_MODE_BECP:
410 // Others use compat mode
411 case IEEE1284_MODE_NIBBLE:
412 case IEEE1284_MODE_BYTE:
413 case IEEE1284_MODE_COMPAT:
415 return !(cpp_daisy(port, 0xe0 + daisy) &
416 PARPORT_STATUS_ERROR);
420 static int mux_present(struct parport *port)
422 return cpp_mux(port, 0x51) == 3;
425 static int num_mux_ports(struct parport *port)
427 return cpp_mux(port, 0x58);
430 static int select_port(struct parport *port)
432 int muxport = port->muxport;
433 return cpp_mux(port, 0x60 + muxport) == muxport;
436 static int assign_addrs(struct parport *port)
440 int thisdev = numdevs;
444 parport_data_forward(port);
445 parport_write_data(port, 0xaa); udelay(2);
446 parport_write_data(port, 0x55); udelay(2);
447 parport_write_data(port, 0x00); udelay(2);
448 parport_write_data(port, 0xff); udelay(2);
449 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
450 | PARPORT_STATUS_PAPEROUT
451 | PARPORT_STATUS_SELECT
452 | PARPORT_STATUS_ERROR);
453 if (s != (PARPORT_STATUS_BUSY
454 | PARPORT_STATUS_PAPEROUT
455 | PARPORT_STATUS_SELECT
456 | PARPORT_STATUS_ERROR)) {
457 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
462 parport_write_data(port, 0x87); udelay(2);
463 s = parport_read_status(port) & (PARPORT_STATUS_BUSY
464 | PARPORT_STATUS_PAPEROUT
465 | PARPORT_STATUS_SELECT
466 | PARPORT_STATUS_ERROR);
467 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
468 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
473 parport_write_data(port, 0x78); udelay(2);
474 s = parport_read_status(port);
477 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT))
478 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)
481 parport_write_data(port, daisy);
483 parport_frob_control(port,
484 PARPORT_CONTROL_STROBE,
485 PARPORT_CONTROL_STROBE);
487 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
490 add_dev(numdevs++, port, daisy);
492 /* See if this device thought it was the last in the
494 if (!(s & PARPORT_STATUS_BUSY))
497 /* We are seeing pass through status now. We see
498 last_dev from next device or if last_dev does not
499 work status lines from some non-daisy chain
501 s = parport_read_status(port);
504 parport_write_data(port, 0xff); udelay(2);
505 detected = numdevs - thisdev;
506 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
509 /* Ask the new devices to introduce themselves. */
510 deviceid = kmalloc(1024, GFP_KERNEL);
511 if (!deviceid) return 0;
513 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
514 parport_device_id(thisdev, deviceid, 1024);