drivers/parport/daisy.c

   1 /*
   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/parport.h>
  23 #include <linux/delay.h>
  24 #include <asm/uaccess.h>
  25
  26 #define DEBUG /* undef me for production */
  27
  28 #ifdef DEBUG
  29 #define DPRINTK(stuff...) printk (stuff)
  30 #else
  31 #define DPRINTK(stuff...)
  32 #endif
  33
  34 static struct daisydev {
  35         struct daisydev *next;
  36         struct parport *port;
  37         int daisy;
  38         int devnum;
  39 } *topology = NULL;
  40
  41 static int numdevs = 0;
  42
  43 /* Forward-declaration of lower-level functions. */
  44 static int mux_present (struct parport *port);
  45 static int num_mux_ports (struct parport *port);
  46 static int select_port (struct parport *port);
  47 static int assign_addrs (struct parport *port);
  48
  49 /* Add a device to the discovered topology. */
  50 static void add_dev (int devnum, struct parport *port, int daisy)
  51 {
  52         struct daisydev *newdev;
  53         newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL);
  54         if (newdev) {
  55                 newdev->port = port;
  56                 newdev->daisy = daisy;
  57                 newdev->devnum = devnum;
  58                 newdev->next = topology;
  59                 if (!topology || topology->devnum >= devnum)
  60                         topology = newdev;
  61                 else {
  62                         struct daisydev *prev = topology;
  63                         while (prev->next && prev->next->devnum < devnum)
  64                                 prev = prev->next;
  65                         newdev->next = prev->next;
  66                         prev->next = newdev;
  67                 }
  68         }
  69 }
  70
  71 /* Clone a parport (actually, make an alias). */
  72 static struct parport *clone_parport (struct parport *real, int muxport)
  73 {
  74         struct parport *extra = parport_register_port (real->base,
  75                                                        real->irq,
  76                                                        real->dma,
  77                                                        real->ops);
  78         if (extra) {
  79                 extra->portnum = real->portnum;
  80                 extra->physport = real;
  81                 extra->muxport = muxport;
  82         }
  83
  84         return extra;
  85 }
  86
  87 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
  88  * Return value is number of devices actually detected. */
  89 int parport_daisy_init (struct parport *port)
  90 {
  91         int detected = 0;
  92         char *deviceid;
  93         static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
  94         int num_ports;
  95         int i;
  96
  97         /* Because this is called before any other devices exist,
  98          * we don't have to claim exclusive access.  */
  99
 100         /* If mux present on normal port, need to create new
 101          * parports for each extra port. */
 102         if (port->muxport < 0 && mux_present (port) &&
 103             /* don't be fooled: a mux must have 2 or 4 ports. */
 104             ((num_ports = num_mux_ports (port)) == 2 || num_ports == 4)) {
 105                 /* Leave original as port zero. */
 106                 port->muxport = 0;
 107                 printk (KERN_INFO
 108                         "%s: 1st (default) port of %d-way multiplexor\n",
 109                         port->name, num_ports);
 110                 for (i = 1; i < num_ports; i++) {
 111                         /* Clone the port. */
 112                         struct parport *extra = clone_parport (port, i);
 113                         if (!extra) {
 114                                 if (signal_pending (current))
 115                                         break;
 116
 117                                 schedule ();
 118                                 continue;
 119                         }
 120
 121                         printk (KERN_INFO
 122                                 "%s: %d%s port of %d-way multiplexor on %s\n",
 123                                 extra->name, i + 1, th[i + 1], num_ports,
 124                                 port->name);
 125
 126                         /* Analyse that port too.  We won't recurse
 127                            forever because of the 'port->muxport < 0'
 128                            test above. */
 129                         parport_announce_port (extra);
 130                 }
 131         }
 132
 133         if (port->muxport >= 0)
 134                 select_port (port);
 135
 136         parport_daisy_deselect_all (port);
 137         detected += assign_addrs (port);
 138
 139         /* Count the potential legacy device at the end. */
 140         add_dev (numdevs++, port, -1);
 141
 142         /* Find out the legacy device's IEEE 1284 device ID. */
 143         deviceid = kmalloc (1000, GFP_KERNEL);
 144         if (deviceid) {
 145                 if (parport_device_id (numdevs - 1, deviceid, 1000) > 2)
 146                         detected++;
 147
 148                 kfree (deviceid);
 149         }
 150
 151         return detected;
 152 }
 153
 154 /* Forget about devices on a physical port. */
 155 void parport_daisy_fini (struct parport *port)
 156 {
 157         struct daisydev *dev, *prev = topology;
 158         while (prev && prev->port == port) {
 159                 topology = topology->next;
 160                 kfree (prev);
 161                 prev = topology;
 162         }
 163
 164         while (prev) {
 165                 dev = prev->next;
 166                 if (dev && dev->port == port) {
 167                         prev->next = dev->next;
 168                         kfree (dev);
 169                 }
 170                 prev = prev->next;
 171         }
 172
 173         /* Gaps in the numbering could be handled better.  How should
 174            someone enumerate through all IEEE1284.3 devices in the
 175            topology?. */
 176         if (!topology) numdevs = 0;
 177         return;
 178 }
 179
 180 /**
 181  *      parport_open - find a device by canonical device number
 182  *      @devnum: canonical device number
 183  *      @name: name to associate with the device
 184  *      @pf: preemption callback
 185  *      @kf: kick callback
 186  *      @irqf: interrupt handler
 187  *      @flags: registration flags
 188  *      @handle: driver data
 189  *
 190  *      This function is similar to parport_register_device(), except
 191  *      that it locates a device by its number rather than by the port
 192  *      it is attached to.  See parport_find_device() and
 193  *      parport_find_class().
 194  *
 195  *      All parameters except for @devnum are the same as for
 196  *      parport_register_device().  The return value is the same as
 197  *      for parport_register_device().
 198  **/
 199
 200 struct pardevice *parport_open (int devnum, const char *name,
 201                                 int (*pf) (void *), void (*kf) (void *),
 202                                 void (*irqf) (int, void *, struct pt_regs *),
 203                                 int flags, void *handle)
 204 {
 205         struct parport *port = parport_enumerate ();
 206         struct pardevice *dev;
 207         int portnum;
 208         int muxnum;
 209         int daisynum;
 210
 211         if (parport_device_coords (devnum,  &portnum, &muxnum, &daisynum))
 212                 return NULL;
 213
 214         while (port && ((port->portnum != portnum) ||
 215                         (port->muxport != muxnum)))
 216                 port = port->next;
 217
 218         if (!port)
 219                 /* No corresponding parport. */
 220                 return NULL;
 221
 222         dev = parport_register_device (port, name, pf, kf,
 223                                        irqf, flags, handle);
 224         if (dev)
 225                 dev->daisy = daisynum;
 226
 227         /* Check that there really is a device to select. */
 228         if (daisynum >= 0) {
 229                 int selected;
 230                 parport_claim_or_block (dev);
 231                 selected = port->daisy;
 232                 parport_release (dev);
 233
 234                 if (selected != port->daisy) {
 235                         /* No corresponding device. */
 236                         parport_unregister_device (dev);
 237                         return NULL;
 238                 }
 239         }
 240
 241         return dev;
 242 }
 243
 244 /**
 245  *      parport_close - close a device opened with parport_open()
 246  *      @dev: device to close
 247  *
 248  *      This is to parport_open() as parport_unregister_device() is to
 249  *      parport_register_device().
 250  **/
 251
 252 void parport_close (struct pardevice *dev)
 253 {
 254         parport_unregister_device (dev);
 255 }
 256
 257 /**
 258  *      parport_device_num - convert device coordinates
 259  *      @parport: parallel port number
 260  *      @mux: multiplexor port number (-1 for no multiplexor)
 261  *      @daisy: daisy chain address (-1 for no daisy chain address)
 262  *
 263  *      This tries to locate a device on the given parallel port,
 264  *      multiplexor port and daisy chain address, and returns its
 265  *      device number or -NXIO if no device with those coordinates
 266  *      exists.
 267  **/
 268
 269 int parport_device_num (int parport, int mux, int daisy)
 270 {
 271         struct daisydev *dev = topology;
 272
 273         while (dev && dev->port->portnum != parport &&
 274                dev->port->muxport != mux && dev->daisy != daisy)
 275                 dev = dev->next;
 276
 277         if (!dev)
 278                 return -ENXIO;
 279
 280         return dev->devnum;
 281 }
 282
 283 /**
 284  *      parport_device_coords - convert canonical device number
 285  *      @devnum: device number
 286  *      @parport: pointer to storage for parallel port number
 287  *      @mux: pointer to storage for multiplexor port number
 288  *      @daisy: pointer to storage for daisy chain address
 289  *
 290  *      This function converts a device number into its coordinates in
 291  *      terms of which parallel port in the system it is attached to,
 292  *      which multiplexor port it is attached to if there is a
 293  *      multiplexor on that port, and which daisy chain address it has
 294  *      if it is in a daisy chain.
 295  *
 296  *      The caller must allocate storage for @parport, @mux, and
 297  *      @daisy.
 298  *
 299  *      If there is no device with the specified device number, -ENXIO
 300  *      is returned.  Otherwise, the values pointed to by @parport,
 301  *      @mux, and @daisy are set to the coordinates of the device,
 302  *      with -1 for coordinates with no value.
 303  *
 304  *      This function is not actually very useful, but this interface
 305  *      was suggested by IEEE 1284.3.
 306  **/
 307
 308 int parport_device_coords (int devnum, int *parport, int *mux, int *daisy)
 309 {
 310         struct daisydev *dev = topology;
 311
 312         while (dev && dev->devnum != devnum)
 313                 dev = dev->next;
 314
 315         if (!dev)
 316                 return -ENXIO;
 317
 318         if (parport) *parport = dev->port->portnum;
 319         if (mux) *mux = dev->port->muxport;
 320         if (daisy) *daisy = dev->daisy;
 321         return 0;
 322 }
 323
 324 /* Send a daisy-chain-style CPP command packet. */
 325 static int cpp_daisy (struct parport *port, int cmd)
 326 {
 327         unsigned char s;
 328
 329         parport_data_forward (port);
 330         parport_write_data (port, 0xaa); udelay (2);
 331         parport_write_data (port, 0x55); udelay (2);
 332         parport_write_data (port, 0x00); udelay (2);
 333         parport_write_data (port, 0xff); udelay (2);
 334         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 335                                           | PARPORT_STATUS_PAPEROUT
 336                                           | PARPORT_STATUS_SELECT
 337                                           | PARPORT_STATUS_ERROR);
 338         if (s != (PARPORT_STATUS_BUSY
 339                   | PARPORT_STATUS_PAPEROUT
 340                   | PARPORT_STATUS_SELECT
 341                   | PARPORT_STATUS_ERROR)) {
 342                 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n",
 343                          port->name, s);
 344                 return -ENXIO;
 345         }
 346
 347         parport_write_data (port, 0x87); udelay (2);
 348         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 349                                           | PARPORT_STATUS_PAPEROUT
 350                                           | PARPORT_STATUS_SELECT
 351                                           | PARPORT_STATUS_ERROR);
 352         if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
 353                 DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n",
 354                          port->name, s);
 355                 return -ENXIO;
 356         }
 357
 358         parport_write_data (port, 0x78); udelay (2);
 359         parport_write_data (port, cmd); udelay (2);
 360         parport_frob_control (port,
 361                               PARPORT_CONTROL_STROBE,
 362                               PARPORT_CONTROL_STROBE);
 363         udelay (1);
 364         parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
 365         udelay (1);
 366         s = parport_read_status (port);
 367         parport_write_data (port, 0xff); udelay (2);
 368
 369         return s;
 370 }
 371
 372 /* Send a mux-style CPP command packet. */
 373 static int cpp_mux (struct parport *port, int cmd)
 374 {
 375         unsigned char s;
 376         int rc;
 377
 378         parport_data_forward (port);
 379         parport_write_data (port, 0xaa); udelay (2);
 380         parport_write_data (port, 0x55); udelay (2);
 381         parport_write_data (port, 0xf0); udelay (2);
 382         parport_write_data (port, 0x0f); udelay (2);
 383         parport_write_data (port, 0x52); udelay (2);
 384         parport_write_data (port, 0xad); udelay (2);
 385         parport_write_data (port, cmd); udelay (2);
 386
 387         s = parport_read_status (port);
 388         if (!(s & PARPORT_STATUS_ACK)) {
 389                 DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
 390                          port->name, cmd, s);
 391                 return -EIO;
 392         }
 393
 394         rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
 395               ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
 396               ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
 397               ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));
 398
 399         return rc;
 400 }
 401
 402 void parport_daisy_deselect_all (struct parport *port)
 403 {
 404         cpp_daisy (port, 0x30);
 405 }
 406
 407 int parport_daisy_select (struct parport *port, int daisy, int mode)
 408 {
 409         /* mode is currently ignored. FIXME? */
 410         return cpp_daisy (port, 0xe0 + daisy) & PARPORT_STATUS_ERROR;
 411 }
 412
 413 static int mux_present (struct parport *port)
 414 {
 415         return cpp_mux (port, 0x51) == 3;
 416 }
 417
 418 static int num_mux_ports (struct parport *port)
 419 {
 420         return cpp_mux (port, 0x58);
 421 }
 422
 423 static int select_port (struct parport *port)
 424 {
 425         int muxport = port->muxport;
 426         return cpp_mux (port, 0x60 + muxport) == muxport;
 427 }
 428
 429 static int assign_addrs (struct parport *port)
 430 {
 431         unsigned char s, last_dev;
 432         unsigned char daisy;
 433         int thisdev = numdevs;
 434         int detected;
 435         char *deviceid;
 436
 437         parport_data_forward (port);
 438         parport_write_data (port, 0xaa); udelay (2);
 439         parport_write_data (port, 0x55); udelay (2);
 440         parport_write_data (port, 0x00); udelay (2);
 441         parport_write_data (port, 0xff); udelay (2);
 442         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 443                                           | PARPORT_STATUS_PAPEROUT
 444                                           | PARPORT_STATUS_SELECT
 445                                           | PARPORT_STATUS_ERROR);
 446         if (s != (PARPORT_STATUS_BUSY
 447                   | PARPORT_STATUS_PAPEROUT
 448                   | PARPORT_STATUS_SELECT
 449                   | PARPORT_STATUS_ERROR)) {
 450                 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n",
 451                          port->name, s);
 452                 return 0;
 453         }
 454
 455         parport_write_data (port, 0x87); udelay (2);
 456         s = parport_read_status (port) & (PARPORT_STATUS_BUSY
 457                                           | PARPORT_STATUS_PAPEROUT
 458                                           | PARPORT_STATUS_SELECT
 459                                           | PARPORT_STATUS_ERROR);
 460         if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
 461                 DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n",
 462                          port->name, s);
 463                 return 0;
 464         }
 465
 466         parport_write_data (port, 0x78); udelay (2);
 467         last_dev = 0; /* We've just been speaking to a device, so we
 468                          know there must be at least _one_ out there. */
 469
 470         for (daisy = 0; daisy < 4; daisy++) {
 471                 parport_write_data (port, daisy);
 472                 udelay (2);
 473                 parport_frob_control (port,
 474                                       PARPORT_CONTROL_STROBE,
 475                                       PARPORT_CONTROL_STROBE);
 476                 udelay (1);
 477                 parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
 478                 udelay (1);
 479
 480                 if (last_dev)
 481                         /* No more devices. */
 482                         break;
 483
 484                 last_dev = !(parport_read_status (port)
 485                              & PARPORT_STATUS_BUSY);
 486
 487                 add_dev (numdevs++, port, daisy);
 488         }
 489
 490         parport_write_data (port, 0xff); udelay (2);
 491         detected = numdevs - thisdev;
 492         DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name,
 493                  detected);
 494
 495         /* Ask the new devices to introduce themselves. */
 496         deviceid = kmalloc (1000, GFP_KERNEL);
 497         if (!deviceid) return 0;
 498
 499         for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
 500                 parport_device_id (thisdev, deviceid, 1000);
 501
 502         kfree (deviceid);
 503         return detected;
 504 }
 505
 506 /* Find a device with a particular manufacturer and model string,
 507    starting from a given device number.  Like the PCI equivalent,
 508    'from' itself is skipped. */
 509
 510 /**
 511  *      parport_find_device - find a specific device
 512  *      @mfg: required manufacturer string
 513  *      @mdl: required model string
 514  *      @from: previous device number found in search, or %NULL for
 515  *             new search
 516  *
 517  *      This walks through the list of parallel port devices looking
 518  *      for a device whose 'MFG' string matches @mfg and whose 'MDL'
 519  *      string matches @mdl in their IEEE 1284 Device ID.
 520  *
 521  *      When a device is found matching those requirements, its device
 522  *      number is returned; if there is no matching device, a negative
 523  *      value is returned.
 524  *
 525  *      A new search it initiated by passing %NULL as the @from
 526  *      argument.  If @from is not %NULL, the search continues from
 527  *      that device.
 528  **/
 529
 530 int parport_find_device (const char *mfg, const char *mdl, int from)
 531 {
 532         struct daisydev *d = topology; /* sorted by devnum */
 533
 534         /* Find where to start. */
 535         while (d && d->devnum <= from)
 536                 d = d->next;
 537
 538         /* Search. */
 539         while (d) {
 540                 struct parport_device_info *info;
 541                 info = &d->port->probe_info[1 + d->daisy];
 542                 if ((!mfg || !strcmp (mfg, info->mfr)) &&
 543                     (!mdl || !strcmp (mdl, info->model)))
 544                         break;
 545
 546                 d = d->next;
 547         }
 548
 549         if (d)
 550                 return d->devnum;
 551
 552         return -1;
 553 }
 554
 555 /**
 556  *      parport_find_class - find a device in a specified class
 557  *      @cls: required class
 558  *      @from: previous device number found in search, or %NULL for
 559  *             new search
 560  *
 561  *      This walks through the list of parallel port devices looking
 562  *      for a device whose 'CLS' string matches @cls in their IEEE
 563  *      1284 Device ID.
 564  *
 565  *      When a device is found matching those requirements, its device
 566  *      number is returned; if there is no matching device, a negative
 567  *      value is returned.
 568  *
 569  *      A new search it initiated by passing %NULL as the @from
 570  *      argument.  If @from is not %NULL, the search continues from
 571  *      that device.
 572  **/
 573
 574 int parport_find_class (parport_device_class cls, int from)
 575 {
 576         struct daisydev *d = topology; /* sorted by devnum */
 577
 578         /* Find where to start. */
 579         while (d && d->devnum <= from)
 580                 d = d->next;
 581
 582         /* Search. */
 583         while (d && d->port->probe_info[1 + d->daisy].class != cls)
 584                 d = d->next;
 585
 586         if (d)
 587                 return d->devnum;
 588
 589         return -1;
 590 }