drivers/parport/daisy.c

   1 /*
   2  * IEEE 1284.3 Parallel port daisy chain and multiplexor code
   3  *
   4  * Copyright (C) 1999  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  *
  16  */
  17
  18 #include <linux/parport.h>
  19 #include <linux/delay.h>
  20 #include <asm/uaccess.h>
  21
  22 #define DEBUG /* undef me for production */
  23
  24 #ifdef DEBUG
  25 #define DPRINTK(stuff...) printk (stuff)
  26 #else
  27 #define DPRINTK(stuff...)
  28 #endif
  29
  30 static struct daisydev {
  31         struct daisydev *next;
  32         struct parport *port;
  33         int daisy;
  34         int devnum;
  35 } *topology = NULL;
  36
  37 static int numdevs = 0;
  38
  39 /* Forward-declaration of lower-level functions. */
  40 static int mux_present (struct parport *port);
  41 static int num_mux_ports (struct parport *port);
  42 static int select_port (struct parport *port);
  43 static int assign_addrs (struct parport *port);
  44
  45 /* Add a device to the discovered topology. */
  46 static void add_dev (int devnum, struct parport *port, int daisy)
  47 {
  48         struct daisydev *newdev;
  49         newdev = kmalloc (GFP_KERNEL, sizeof (struct daisydev));
  50         if (newdev) {
  51                 newdev->port = port;
  52                 newdev->daisy = daisy;
  53                 newdev->devnum = devnum;
  54                 newdev->next = topology;
  55                 if (!topology || topology->devnum >= devnum)
  56                         topology = newdev;
  57                 else {
  58                         struct daisydev *prev = topology;
  59                         while (prev->next && prev->next->devnum < devnum)
  60                                 prev = prev->next;
  61                         newdev->next = prev->next;
  62                         prev->next = newdev;
  63                 }
  64         }
  65 }
  66
  67 /* Clone a parport (actually, make an alias). */
  68 static struct parport *clone_parport (struct parport *real, int muxport)
  69 {
  70         struct parport *extra = parport_register_port (real->base,
  71                                                        real->irq,
  72                                                        real->dma,
  73                                                        real->ops);
  74         if (extra) {
  75                 extra->portnum = real->portnum;
  76                 extra->physport = real;
  77                 extra->muxport = muxport;
  78         }
  79
  80         return extra;
  81 }
  82
  83 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains. */
  84 int parport_daisy_init (struct parport *port)
  85 {
  86         char *deviceid;
  87         static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
  88         int num_ports;
  89         int i;
  90
  91         /* Because this is called before any other devices exist,
  92          * we don't have to claim exclusive access.  */
  93
  94         /* If mux present on normal port, need to create new
  95          * parports for each extra port. */
  96         if (port->muxport < 0 && mux_present (port) &&
  97             /* don't be fooled: a mux must have 2 or 4 ports. */
  98             ((num_ports = num_mux_ports (port)) == 2 || num_ports == 4)) {
  99                 /* Leave original as port zero. */
 100                 port->muxport = 0;
 101                 printk (KERN_INFO
 102                         "%s: 1st (default) port of %d-way multiplexor\n",
 103                         port->name, num_ports);
 104                 for (i = 1; i < num_ports; i++) {
 105                         /* Clone the port. */
 106                         struct parport *extra = clone_parport (port, i);
 107                         if (!extra) {
 108                                 if (signal_pending (current))
 109                                         break;
 110
 111                                 schedule ();
 112                                 continue;
 113                         }
 114
 115                         printk (KERN_INFO
 116                                 "%s: %d%s port of %d-way multiplexor on %s\n",
 117                                 extra->name, i + 1, th[i + 1], num_ports,
 118                                 port->name);
 119
 120                         /* Analyse that port too.  We won't recurse
 121                            forever because of the 'port->muxport < 0'
 122                            test above. */
 123                         parport_announce_port (extra);
 124                 }
 125         }
 126
 127         if (port->muxport >= 0)
 128                 select_port (port);
 129
 130         parport_daisy_deselect_all (port);
 131         assign_addrs (port);
 132
 133         /* Count the potential legacy device at the end. */
 134         add_dev (numdevs++, port, -1);
 135
 136         /* Find out the legacy device's IEEE 1284 device ID. */
 137         deviceid = kmalloc (1000, GFP_KERNEL);
 138         if (deviceid) {
 139                 parport_device_id (numdevs - 1, deviceid, 1000);
 140                 kfree (deviceid);
 141         }
 142
 143         return 0;
 144 }
 145
 146 /* Forget about devices on a physical port. */
 147 void parport_daisy_fini (struct parport *port)
 148 {
 149         struct daisydev *dev, *prev = topology;
 150         while (prev && prev->port == port)
 151                 prev = topology = topology->next;
 152
 153         while (prev) {
 154                 dev = prev->next;
 155                 if (dev && dev->port == port)
 156                         prev->next = dev->next;
 157
 158                 prev = prev->next;
 159         }
 160
 161         /* Gaps in the numbering could be handled better.  How should
 162            someone enumerate through all IEEE1284.3 devices in the
 163            topology?. */
 164         if (!topology) numdevs = 0;
 165         return; }
 166
 167 /* Find a device by canonical device number. */
 168 struct pardevice *parport_open (int devnum, const char *name,
 169                                 int (*pf) (void *), void (*kf) (void *),
 170                                 void (*irqf) (int, void *, struct pt_regs *),
 171                                 int flags, void *handle)
 172 {
 173         struct parport *port = parport_enumerate ();
 174         struct pardevice *dev;
 175         int portnum;
 176         int muxnum;
 177         int daisynum;
 178
 179         if (parport_device_coords (devnum,  &portnum, &muxnum, &daisynum))
 180                 return NULL;
 181
 182         while (port && ((port->portnum != portnum) ||
 183                         (port->muxport != muxnum)))
 184                 port = port->next;
 185
 186         if (!port)
 187                 /* No corresponding parport. */
 188                 return NULL;
 189
 190         dev = parport_register_device (port, name, pf, kf,
 191                                        irqf, flags, handle);
 192         if (dev)
 193                 dev->daisy = daisynum;
 194
 195         /* Check that there really is a device to select. */
 196         if (daisynum >= 0) {
 197                 int selected;
 198                 parport_claim_or_block (dev);
 199                 selected = port->daisy;
 200                 parport_release (dev);
 201
 202                 if (selected != port->daisy) {
 203                         /* No corresponding device. */
 204                         parport_unregister_device (dev);
 205                         return NULL;
 206                 }
 207         }
 208
 209         return dev;
 210 }
 211
 212 /* The converse of parport_open. */
 213 void parport_close (struct pardevice *dev)
 214 {
 215         parport_unregister_device (dev);
 216 }
 217
 218 /* Convert device coordinates into a canonical device number. */
 219 int parport_device_num (int parport, int mux, int daisy)
 220 {
 221         struct daisydev *dev = topology;
 222
 223         while (dev && dev->port->portnum != parport &&
 224                dev->port->muxport != mux && dev->daisy != daisy)
 225                 dev = dev->next;
 226
 227         if (!dev)
 228                 return -ENXIO;
 229
 230         return dev->devnum;
 231 }
 232
 233 /* Convert a canonical device number into device coordinates. */
 234 int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
 235 {
 236         struct daisydev *dev = topology;
 237
 238         while (dev && dev->devnum != devnum)
 239                 dev = dev->next;
 240
 241         if (!dev)
 242                 return -ENXIO;
 243
 244         if (parport) *parport = dev->port->portnum;
 245         if (mux) *mux = dev->port->muxport;
 246         if (daisy) *daisy = dev->daisy;
 247         return 0;
 248 }
 249
 250 /* Send a daisy-chain-style CPP command packet. */
 251 static int cpp_daisy (struct parport *port, int cmd)
 252 {
 253         unsigned char s;
 254
 255         parport_write_data (port, 0xaa); udelay (2);
 256         parport_write_data (port, 0x55); udelay (2);
 257         parport_write_data (port, 0x00); udelay (2);
 258         parport_write_data (port, 0xff); udelay (2);
 259         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 260                                           | PARPORT_STATUS_PAPEROUT
 261                                           | PARPORT_STATUS_SELECT
 262                                           | PARPORT_STATUS_ERROR);
 263         if (s != (PARPORT_STATUS_BUSY
 264                   | PARPORT_STATUS_PAPEROUT
 265                   | PARPORT_STATUS_SELECT
 266                   | PARPORT_STATUS_ERROR)) {
 267                 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
 268                          port->name, s);
 269                 return -ENXIO;
 270         }
 271
 272         parport_write_data (port, 0x87); udelay (2);
 273         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 274                                           | PARPORT_STATUS_PAPEROUT
 275                                           | PARPORT_STATUS_SELECT
 276                                           | PARPORT_STATUS_ERROR);
 277         if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
 278                 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
 279                          port->name, s);
 280                 return -ENXIO;
 281         }
 282
 283         parport_write_data (port, 0x78); udelay (2);
 284         parport_write_data (port, cmd); udelay (2);
 285         parport_frob_control (port,
 286                               PARPORT_CONTROL_STROBE,
 287                               PARPORT_CONTROL_STROBE);
 288         udelay (1);
 289         parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
 290         udelay (1);
 291         s = parport_read_status (port);
 292         parport_write_data (port, 0xff); udelay (2);
 293
 294         return s;
 295 }
 296
 297 /* Send a mux-style CPP command packet. */
 298 static int cpp_mux (struct parport *port, int cmd)
 299 {
 300         unsigned char s;
 301         int rc;
 302
 303         parport_write_data (port, 0xaa); udelay (2);
 304         parport_write_data (port, 0x55); udelay (2);
 305         parport_write_data (port, 0xf0); udelay (2);
 306         parport_write_data (port, 0x0f); udelay (2);
 307         parport_write_data (port, 0x52); udelay (2);
 308         parport_write_data (port, 0xad); udelay (2);
 309         parport_write_data (port, cmd); udelay (2);
 310
 311         s = parport_read_status (port);
 312         if (!(s & PARPORT_STATUS_ACK)) {
 313                 DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
 314                          port->name, cmd, s);
 315                 return -EIO;
 316         }
 317
 318         rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
 319               ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
 320               ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
 321               ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));
 322
 323         return rc;
 324 }
 325
 326 void parport_daisy_deselect_all (struct parport *port)
 327 {
 328         cpp_daisy (port, 0x30);
 329 }
 330
 331 int parport_daisy_select (struct parport *port, int daisy, int mode)
 332 {
 333         /* mode is currently ignored. FIXME? */
 334         return cpp_daisy (port, 0xe0 + daisy) & PARPORT_STATUS_ERROR;
 335 }
 336
 337 static int mux_present (struct parport *port)
 338 {
 339         return cpp_mux (port, 0x51) == 3;
 340 }
 341
 342 static int num_mux_ports (struct parport *port)
 343 {
 344         return cpp_mux (port, 0x58);
 345 }
 346
 347 static int select_port (struct parport *port)
 348 {
 349         int muxport = port->muxport;
 350         return cpp_mux (port, 0x60 + muxport) == muxport;
 351 }
 352
 353 static int assign_addrs (struct parport *port)
 354 {
 355         unsigned char s, last_dev;
 356         unsigned char daisy;
 357         int thisdev = numdevs;
 358         char *deviceid;
 359
 360         parport_write_data (port, 0xaa); udelay (2);
 361         parport_write_data (port, 0x55); udelay (2);
 362         parport_write_data (port, 0x00); udelay (2);
 363         parport_write_data (port, 0xff); udelay (2);
 364         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 365                                           | PARPORT_STATUS_PAPEROUT
 366                                           | PARPORT_STATUS_SELECT
 367                                           | PARPORT_STATUS_ERROR);
 368         if (s != (PARPORT_STATUS_BUSY
 369                   | PARPORT_STATUS_PAPEROUT
 370                   | PARPORT_STATUS_SELECT
 371                   | PARPORT_STATUS_ERROR)) {
 372                 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
 373                          port->name, s);
 374                 return -ENXIO;
 375         }
 376
 377         parport_write_data (port, 0x87); udelay (2);
 378         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 379                                           | PARPORT_STATUS_PAPEROUT
 380                                           | PARPORT_STATUS_SELECT
 381                                           | PARPORT_STATUS_ERROR);
 382         if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
 383                 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
 384                          port->name, s);
 385                 return -ENXIO;
 386         }
 387
 388         parport_write_data (port, 0x78); udelay (2);
 389         last_dev = 0; /* We've just been speaking to a device, so we
 390                          know there must be at least _one_ out there. */
 391
 392         for (daisy = 0; daisy < 4; daisy++) {
 393                 parport_write_data (port, daisy);
 394                 udelay (2);
 395                 parport_frob_control (port,
 396                                       PARPORT_CONTROL_STROBE,
 397                                       PARPORT_CONTROL_STROBE);
 398                 udelay (1);
 399                 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
 400                 udelay (1);
 401
 402                 if (last_dev)
 403                         /* No more devices. */
 404                         break;
 405
 406                 last_dev = !(parport_read_status (port)
 407                              & PARPORT_STATUS_BUSY);
 408
 409                 add_dev (numdevs++, port, daisy);
 410         }
 411
 412         parport_write_data (port, 0xff); udelay (2);
 413         DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
 414                 numdevs - thisdev);
 415
 416         /* Ask the new devices to introduce themselves. */
 417         deviceid = kmalloc (1000, GFP_KERNEL);
 418         if (!deviceid) return 0;
 419
 420         for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
 421                 parport_device_id (thisdev, deviceid, 1000);
 422
 423         kfree (deviceid);
 424         return 0;
 425 }
 426
 427 /* Find a device with a particular manufacturer and model string,
 428    starting from a given device number.  Like the PCI equivalent,
 429    'from' itself is skipped. */
 430 int parport_find_device (const char *mfg, const char *mdl, int from)
 431 {
 432         struct daisydev *d = topology; /* sorted by devnum */
 433
 434         /* Find where to start. */
 435         while (d && d->devnum <= from)
 436                 d = d->next;
 437
 438         /* Search. */
 439         while (d) {
 440                 struct parport_device_info *info;
 441                 info = &d->port->probe_info[1 + d->daisy];
 442                 if ((!mfg || !strcmp (mfg, info->mfr)) &&
 443                     (!mdl || !strcmp (mdl, info->model)))
 444                         break;
 445
 446                 d = d->next;
 447         }
 448
 449         if (d)
 450                 return d->devnum;
 451
 452         return -1;
 453 }
 454
 455 /* Find a device in a particular class.  Like the PCI equivalent,
 456    'from' itself is skipped. */
 457 int parport_find_class (parport_device_class cls, int from)
 458 {
 459         struct daisydev *d = topology; /* sorted by devnum */
 460
 461         /* Find where to start. */
 462         while (d && d->devnum <= from)
 463                 d = d->next;
 464
 465         /* Search. */
 466         while (d && d->port->probe_info[1 + d->daisy].class != cls)
 467                 d = d->next;
 468
 469         if (d)
 470                 return d->devnum;
 471
 472         return -1;
 473 }