1/* 2 pg.c (c) 1998 Grant R. Guenther <grant@torque.net> 3 Under the terms of the GNU General Public License. 4 5 The pg driver provides a simple character device interface for 6 sending ATAPI commands to a device. With the exception of the 7 ATAPI reset operation, all operations are performed by a pair 8 of read and write operations to the appropriate /dev/pgN device. 9 A write operation delivers a command and any outbound data in 10 a single buffer. Normally, the write will succeed unless the 11 device is offline or malfunctioning, or there is already another 12 command pending. If the write succeeds, it should be followed 13 immediately by a read operation, to obtain any returned data and 14 status information. A read will fail if there is no operation 15 in progress. 16 17 As a special case, the device can be reset with a write operation, 18 and in this case, no following read is expected, or permitted. 19 20 There are no ioctl() operations. Any single operation 21 may transfer at most PG_MAX_DATA bytes. Note that the driver must 22 copy the data through an internal buffer. In keeping with all 23 current ATAPI devices, command packets are assumed to be exactly 24 12 bytes in length. 25 26 To permit future changes to this interface, the headers in the 27 read and write buffers contain a single character "magic" flag. 28 Currently this flag must be the character "P". 29 30 By default, the driver will autoprobe for a single parallel 31 port ATAPI device, but if their individual parameters are 32 specified, the driver can handle up to 4 devices. 33 34 To use this device, you must have the following device 35 special files defined: 36 37 /dev/pg0 c 97 0 38 /dev/pg1 c 97 1 39 /dev/pg2 c 97 2 40 /dev/pg3 c 97 3 41 42 (You'll need to change the 97 to something else if you use 43 the 'major' parameter to install the driver on a different 44 major number.) 45 46 The behaviour of the pg driver can be altered by setting 47 some parameters from the insmod command line. The following 48 parameters are adjustable: 49 50 drive0 These four arguments can be arrays of 51 drive1 1-6 integers as follows: 52 drive2 53 drive3 <prt>,<pro>,<uni>,<mod>,<slv>,<dly> 54 55 Where, 56 57 <prt> is the base of the parallel port address for 58 the corresponding drive. (required) 59 60 <pro> is the protocol number for the adapter that 61 supports this drive. These numbers are 62 logged by 'paride' when the protocol modules 63 are initialised. (0 if not given) 64 65 <uni> for those adapters that support chained 66 devices, this is the unit selector for the 67 chain of devices on the given port. It should 68 be zero for devices that don't support chaining. 69 (0 if not given) 70 71 <mod> this can be -1 to choose the best mode, or one 72 of the mode numbers supported by the adapter. 73 (-1 if not given) 74 75 <slv> ATAPI devices can be jumpered to master or slave. 76 Set this to 0 to choose the master drive, 1 to 77 choose the slave, -1 (the default) to choose the 78 first drive found. 79 80 <dly> some parallel ports require the driver to 81 go more slowly. -1 sets a default value that 82 should work with the chosen protocol. Otherwise, 83 set this to a small integer, the larger it is 84 the slower the port i/o. In some cases, setting 85 this to zero will speed up the device. (default -1) 86 87 major You may use this parameter to overide the 88 default major number (97) that this driver 89 will use. Be sure to change the device 90 name as well. 91 92 name This parameter is a character string that 93 contains the name the kernel will use for this 94 device (in /proc output, for instance). 95 (default "pg"). 96 97 verbose This parameter controls the amount of logging 98 that is done by the driver. Set it to 0 for 99 quiet operation, to 1 to enable progress 100 messages while the driver probes for devices, 101 or to 2 for full debug logging. (default 0) 102 103 If this driver is built into the kernel, you can use 104 the following command line parameters, with the same values 105 as the corresponding module parameters listed above: 106 107 pg.drive0 108 pg.drive1 109 pg.drive2 110 pg.drive3 111 112 In addition, you can use the parameter pg.disable to disable 113 the driver entirely. 114 115*/ 116 117/* Changes: 118 119 1.01 GRG 1998.06.16 Bug fixes 120 1.02 GRG 1998.09.24 Added jumbo support 121 122*/ 123 124#define PG_VERSION "1.02" 125#define PG_MAJOR 97 126#define PG_NAME "pg" 127#define PG_UNITS 4 128 129#ifndef PI_PG 130#define PI_PG 4 131#endif 132 133#include <linux/types.h> 134/* Here are things one can override from the insmod command. 135 Most are autoprobed by paride unless set here. Verbose is 0 136 by default. 137 138*/ 139 140static bool verbose = 0; 141static int major = PG_MAJOR; 142static char *name = PG_NAME; 143static int disable = 0; 144 145static int drive0[6] = { 0, 0, 0, -1, -1, -1 }; 146static int drive1[6] = { 0, 0, 0, -1, -1, -1 }; 147static int drive2[6] = { 0, 0, 0, -1, -1, -1 }; 148static int drive3[6] = { 0, 0, 0, -1, -1, -1 }; 149 150static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3}; 151static int pg_drive_count; 152 153enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY}; 154 155/* end of parameters */ 156 157#include <linux/module.h> 158#include <linux/init.h> 159#include <linux/fs.h> 160#include <linux/delay.h> 161#include <linux/slab.h> 162#include <linux/mtio.h> 163#include <linux/pg.h> 164#include <linux/device.h> 165#include <linux/sched.h> /* current, TASK_* */ 166#include <linux/mutex.h> 167#include <linux/jiffies.h> 168 169#include <asm/uaccess.h> 170 171module_param(verbose, bool, 0644); 172module_param(major, int, 0); 173module_param(name, charp, 0); 174module_param_array(drive0, int, NULL, 0); 175module_param_array(drive1, int, NULL, 0); 176module_param_array(drive2, int, NULL, 0); 177module_param_array(drive3, int, NULL, 0); 178 179#include "paride.h" 180 181#define PG_SPIN_DEL 50 /* spin delay in micro-seconds */ 182#define PG_SPIN 200 183#define PG_TMO HZ 184#define PG_RESET_TMO 10*HZ 185 186#define STAT_ERR 0x01 187#define STAT_INDEX 0x02 188#define STAT_ECC 0x04 189#define STAT_DRQ 0x08 190#define STAT_SEEK 0x10 191#define STAT_WRERR 0x20 192#define STAT_READY 0x40 193#define STAT_BUSY 0x80 194 195#define ATAPI_IDENTIFY 0x12 196 197static DEFINE_MUTEX(pg_mutex); 198static int pg_open(struct inode *inode, struct file *file); 199static int pg_release(struct inode *inode, struct file *file); 200static ssize_t pg_read(struct file *filp, char __user *buf, 201 size_t count, loff_t * ppos); 202static ssize_t pg_write(struct file *filp, const char __user *buf, 203 size_t count, loff_t * ppos); 204static int pg_detect(void); 205 206#define PG_NAMELEN 8 207 208struct pg { 209 struct pi_adapter pia; /* interface to paride layer */ 210 struct pi_adapter *pi; 211 int busy; /* write done, read expected */ 212 int start; /* jiffies at command start */ 213 int dlen; /* transfer size requested */ 214 unsigned long timeout; /* timeout requested */ 215 int status; /* last sense key */ 216 int drive; /* drive */ 217 unsigned long access; /* count of active opens ... */ 218 int present; /* device present ? */ 219 char *bufptr; 220 char name[PG_NAMELEN]; /* pg0, pg1, ... */ 221}; 222 223static struct pg devices[PG_UNITS]; 224 225static int pg_identify(struct pg *dev, int log); 226 227static char pg_scratch[512]; /* scratch block buffer */ 228 229static struct class *pg_class; 230 231/* kernel glue structures */ 232 233static const struct file_operations pg_fops = { 234 .owner = THIS_MODULE, 235 .read = pg_read, 236 .write = pg_write, 237 .open = pg_open, 238 .release = pg_release, 239 .llseek = noop_llseek, 240}; 241 242static void pg_init_units(void) 243{ 244 int unit; 245 246 pg_drive_count = 0; 247 for (unit = 0; unit < PG_UNITS; unit++) { 248 int *parm = *drives[unit]; 249 struct pg *dev = &devices[unit]; 250 dev->pi = &dev->pia; 251 clear_bit(0, &dev->access); 252 dev->busy = 0; 253 dev->present = 0; 254 dev->bufptr = NULL; 255 dev->drive = parm[D_SLV]; 256 snprintf(dev->name, PG_NAMELEN, "%s%c", name, 'a'+unit); 257 if (parm[D_PRT]) 258 pg_drive_count++; 259 } 260} 261 262static inline int status_reg(struct pg *dev) 263{ 264 return pi_read_regr(dev->pi, 1, 6); 265} 266 267static inline int read_reg(struct pg *dev, int reg) 268{ 269 return pi_read_regr(dev->pi, 0, reg); 270} 271 272static inline void write_reg(struct pg *dev, int reg, int val) 273{ 274 pi_write_regr(dev->pi, 0, reg, val); 275} 276 277static inline u8 DRIVE(struct pg *dev) 278{ 279 return 0xa0+0x10*dev->drive; 280} 281 282static void pg_sleep(int cs) 283{ 284 schedule_timeout_interruptible(cs); 285} 286 287static int pg_wait(struct pg *dev, int go, int stop, unsigned long tmo, char *msg) 288{ 289 int j, r, e, s, p, to; 290 291 dev->status = 0; 292 293 j = 0; 294 while ((((r = status_reg(dev)) & go) || (stop && (!(r & stop)))) 295 && time_before(jiffies, tmo)) { 296 if (j++ < PG_SPIN) 297 udelay(PG_SPIN_DEL); 298 else 299 pg_sleep(1); 300 } 301 302 to = time_after_eq(jiffies, tmo); 303 304 if ((r & (STAT_ERR & stop)) || to) { 305 s = read_reg(dev, 7); 306 e = read_reg(dev, 1); 307 p = read_reg(dev, 2); 308 if (verbose > 1) 309 printk("%s: %s: stat=0x%x err=0x%x phase=%d%s\n", 310 dev->name, msg, s, e, p, to ? " timeout" : ""); 311 if (to) 312 e |= 0x100; 313 dev->status = (e >> 4) & 0xff; 314 return -1; 315 } 316 return 0; 317} 318 319static int pg_command(struct pg *dev, char *cmd, int dlen, unsigned long tmo) 320{ 321 int k; 322 323 pi_connect(dev->pi); 324 325 write_reg(dev, 6, DRIVE(dev)); 326 327 if (pg_wait(dev, STAT_BUSY | STAT_DRQ, 0, tmo, "before command")) 328 goto fail; 329 330 write_reg(dev, 4, dlen % 256); 331 write_reg(dev, 5, dlen / 256); 332 write_reg(dev, 7, 0xa0); /* ATAPI packet command */ 333 334 if (pg_wait(dev, STAT_BUSY, STAT_DRQ, tmo, "command DRQ")) 335 goto fail; 336 337 if (read_reg(dev, 2) != 1) { 338 printk("%s: command phase error\n", dev->name); 339 goto fail; 340 } 341 342 pi_write_block(dev->pi, cmd, 12); 343 344 if (verbose > 1) { 345 printk("%s: Command sent, dlen=%d packet= ", dev->name, dlen); 346 for (k = 0; k < 12; k++) 347 printk("%02x ", cmd[k] & 0xff); 348 printk("\n"); 349 } 350 return 0; 351fail: 352 pi_disconnect(dev->pi); 353 return -1; 354} 355 356static int pg_completion(struct pg *dev, char *buf, unsigned long tmo) 357{ 358 int r, d, n, p; 359 360 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR, 361 tmo, "completion"); 362 363 dev->dlen = 0; 364 365 while (read_reg(dev, 7) & STAT_DRQ) { 366 d = (read_reg(dev, 4) + 256 * read_reg(dev, 5)); 367 n = ((d + 3) & 0xfffc); 368 p = read_reg(dev, 2) & 3; 369 if (p == 0) 370 pi_write_block(dev->pi, buf, n); 371 if (p == 2) 372 pi_read_block(dev->pi, buf, n); 373 if (verbose > 1) 374 printk("%s: %s %d bytes\n", dev->name, 375 p ? "Read" : "Write", n); 376 dev->dlen += (1 - p) * d; 377 buf += d; 378 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR, 379 tmo, "completion"); 380 } 381 382 pi_disconnect(dev->pi); 383 384 return r; 385} 386 387static int pg_reset(struct pg *dev) 388{ 389 int i, k, err; 390 int expect[5] = { 1, 1, 1, 0x14, 0xeb }; 391 int got[5]; 392 393 pi_connect(dev->pi); 394 write_reg(dev, 6, DRIVE(dev)); 395 write_reg(dev, 7, 8); 396 397 pg_sleep(20 * HZ / 1000); 398 399 k = 0; 400 while ((k++ < PG_RESET_TMO) && (status_reg(dev) & STAT_BUSY)) 401 pg_sleep(1); 402 403 for (i = 0; i < 5; i++) 404 got[i] = read_reg(dev, i + 1); 405 406 err = memcmp(expect, got, sizeof(got)) ? -1 : 0; 407 408 if (verbose) { 409 printk("%s: Reset (%d) signature = ", dev->name, k); 410 for (i = 0; i < 5; i++) 411 printk("%3x", got[i]); 412 if (err) 413 printk(" (incorrect)"); 414 printk("\n"); 415 } 416 417 pi_disconnect(dev->pi); 418 return err; 419} 420 421static void xs(char *buf, char *targ, int len) 422{ 423 char l = '\0'; 424 int k; 425 426 for (k = 0; k < len; k++) { 427 char c = *buf++; 428 if (c != ' ' && c != l) 429 l = *targ++ = c; 430 } 431 if (l == ' ') 432 targ--; 433 *targ = '\0'; 434} 435 436static int pg_identify(struct pg *dev, int log) 437{ 438 int s; 439 char *ms[2] = { "master", "slave" }; 440 char mf[10], id[18]; 441 char id_cmd[12] = { ATAPI_IDENTIFY, 0, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 }; 442 char buf[36]; 443 444 s = pg_command(dev, id_cmd, 36, jiffies + PG_TMO); 445 if (s) 446 return -1; 447 s = pg_completion(dev, buf, jiffies + PG_TMO); 448 if (s) 449 return -1; 450 451 if (log) { 452 xs(buf + 8, mf, 8); 453 xs(buf + 16, id, 16); 454 printk("%s: %s %s, %s\n", dev->name, mf, id, ms[dev->drive]); 455 } 456 457 return 0; 458} 459 460/* 461 * returns 0, with id set if drive is detected 462 * -1, if drive detection failed 463 */ 464static int pg_probe(struct pg *dev) 465{ 466 if (dev->drive == -1) { 467 for (dev->drive = 0; dev->drive <= 1; dev->drive++) 468 if (!pg_reset(dev)) 469 return pg_identify(dev, 1); 470 } else { 471 if (!pg_reset(dev)) 472 return pg_identify(dev, 1); 473 } 474 return -1; 475} 476 477static int pg_detect(void) 478{ 479 struct pg *dev = &devices[0]; 480 int k, unit; 481 482 printk("%s: %s version %s, major %d\n", name, name, PG_VERSION, major); 483 484 k = 0; 485 if (pg_drive_count == 0) { 486 if (pi_init(dev->pi, 1, -1, -1, -1, -1, -1, pg_scratch, 487 PI_PG, verbose, dev->name)) { 488 if (!pg_probe(dev)) { 489 dev->present = 1; 490 k++; 491 } else 492 pi_release(dev->pi); 493 } 494 495 } else 496 for (unit = 0; unit < PG_UNITS; unit++, dev++) { 497 int *parm = *drives[unit]; 498 if (!parm[D_PRT]) 499 continue; 500 if (pi_init(dev->pi, 0, parm[D_PRT], parm[D_MOD], 501 parm[D_UNI], parm[D_PRO], parm[D_DLY], 502 pg_scratch, PI_PG, verbose, dev->name)) { 503 if (!pg_probe(dev)) { 504 dev->present = 1; 505 k++; 506 } else 507 pi_release(dev->pi); 508 } 509 } 510 511 if (k) 512 return 0; 513 514 printk("%s: No ATAPI device detected\n", name); 515 return -1; 516} 517 518static int pg_open(struct inode *inode, struct file *file) 519{ 520 int unit = iminor(inode) & 0x7f; 521 struct pg *dev = &devices[unit]; 522 int ret = 0; 523 524 mutex_lock(&pg_mutex); 525 if ((unit >= PG_UNITS) || (!dev->present)) { 526 ret = -ENODEV; 527 goto out; 528 } 529 530 if (test_and_set_bit(0, &dev->access)) { 531 ret = -EBUSY; 532 goto out; 533 } 534 535 if (dev->busy) { 536 pg_reset(dev); 537 dev->busy = 0; 538 } 539 540 pg_identify(dev, (verbose > 1)); 541 542 dev->bufptr = kmalloc(PG_MAX_DATA, GFP_KERNEL); 543 if (dev->bufptr == NULL) { 544 clear_bit(0, &dev->access); 545 printk("%s: buffer allocation failed\n", dev->name); 546 ret = -ENOMEM; 547 goto out; 548 } 549 550 file->private_data = dev; 551 552out: 553 mutex_unlock(&pg_mutex); 554 return ret; 555} 556 557static int pg_release(struct inode *inode, struct file *file) 558{ 559 struct pg *dev = file->private_data; 560 561 kfree(dev->bufptr); 562 dev->bufptr = NULL; 563 clear_bit(0, &dev->access); 564 565 return 0; 566} 567 568static ssize_t pg_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) 569{ 570 struct pg *dev = filp->private_data; 571 struct pg_write_hdr hdr; 572 int hs = sizeof (hdr); 573 574 if (dev->busy) 575 return -EBUSY; 576 if (count < hs) 577 return -EINVAL; 578 579 if (copy_from_user(&hdr, buf, hs)) 580 return -EFAULT; 581 582 if (hdr.magic != PG_MAGIC) 583 return -EINVAL; 584 if (hdr.dlen > PG_MAX_DATA) 585 return -EINVAL; 586 if ((count - hs) > PG_MAX_DATA) 587 return -EINVAL; 588 589 if (hdr.func == PG_RESET) { 590 if (count != hs) 591 return -EINVAL; 592 if (pg_reset(dev)) 593 return -EIO; 594 return count; 595 } 596 597 if (hdr.func != PG_COMMAND) 598 return -EINVAL; 599 600 dev->start = jiffies; 601 dev->timeout = hdr.timeout * HZ + HZ / 2 + jiffies; 602 603 if (pg_command(dev, hdr.packet, hdr.dlen, jiffies + PG_TMO)) { 604 if (dev->status & 0x10) 605 return -ETIME; 606 return -EIO; 607 } 608 609 dev->busy = 1; 610 611 if (copy_from_user(dev->bufptr, buf + hs, count - hs)) 612 return -EFAULT; 613 return count; 614} 615 616static ssize_t pg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) 617{ 618 struct pg *dev = filp->private_data; 619 struct pg_read_hdr hdr; 620 int hs = sizeof (hdr); 621 int copy; 622 623 if (!dev->busy) 624 return -EINVAL; 625 if (count < hs) 626 return -EINVAL; 627 628 dev->busy = 0; 629 630 if (pg_completion(dev, dev->bufptr, dev->timeout)) 631 if (dev->status & 0x10) 632 return -ETIME; 633 634 memset(&hdr, 0, sizeof(hdr)); 635 hdr.magic = PG_MAGIC; 636 hdr.dlen = dev->dlen; 637 copy = 0; 638 639 if (hdr.dlen < 0) { 640 hdr.dlen = -1 * hdr.dlen; 641 copy = hdr.dlen; 642 if (copy > (count - hs)) 643 copy = count - hs; 644 } 645 646 hdr.duration = (jiffies - dev->start + HZ / 2) / HZ; 647 hdr.scsi = dev->status & 0x0f; 648 649 if (copy_to_user(buf, &hdr, hs)) 650 return -EFAULT; 651 if (copy > 0) 652 if (copy_to_user(buf + hs, dev->bufptr, copy)) 653 return -EFAULT; 654 return copy + hs; 655} 656 657static int __init pg_init(void) 658{ 659 int unit; 660 int err; 661 662 if (disable){ 663 err = -EINVAL; 664 goto out; 665 } 666 667 pg_init_units(); 668 669 if (pg_detect()) { 670 err = -ENODEV; 671 goto out; 672 } 673 674 err = register_chrdev(major, name, &pg_fops); 675 if (err < 0) { 676 printk("pg_init: unable to get major number %d\n", major); 677 for (unit = 0; unit < PG_UNITS; unit++) { 678 struct pg *dev = &devices[unit]; 679 if (dev->present) 680 pi_release(dev->pi); 681 } 682 goto out; 683 } 684 major = err; /* In case the user specified `major=0' (dynamic) */ 685 pg_class = class_create(THIS_MODULE, "pg"); 686 if (IS_ERR(pg_class)) { 687 err = PTR_ERR(pg_class); 688 goto out_chrdev; 689 } 690 for (unit = 0; unit < PG_UNITS; unit++) { 691 struct pg *dev = &devices[unit]; 692 if (dev->present) 693 device_create(pg_class, NULL, MKDEV(major, unit), NULL, 694 "pg%u", unit); 695 } 696 err = 0; 697 goto out; 698 699out_chrdev: 700 unregister_chrdev(major, "pg"); 701out: 702 return err; 703} 704 705static void __exit pg_exit(void) 706{ 707 int unit; 708 709 for (unit = 0; unit < PG_UNITS; unit++) { 710 struct pg *dev = &devices[unit]; 711 if (dev->present) 712 device_destroy(pg_class, MKDEV(major, unit)); 713 } 714 class_destroy(pg_class); 715 unregister_chrdev(major, name); 716 717 for (unit = 0; unit < PG_UNITS; unit++) { 718 struct pg *dev = &devices[unit]; 719 if (dev->present) 720 pi_release(dev->pi); 721 } 722} 723 724MODULE_LICENSE("GPL"); 725module_init(pg_init) 726module_exit(pg_exit) 727