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ppa.c
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1 /* ppa.c -- low level driver for the IOMEGA PPA3
2  * parallel port SCSI host adapter.
3  *
4  * (The PPA3 is the embedded controller in the ZIP drive.)
5  *
6  * (c) 1995,1996 Grant R. Guenther, [email protected],
7  * under the terms of the GNU General Public License.
8  *
9  */
10 
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/blkdev.h>
16 #include <linux/parport.h>
17 #include <linux/workqueue.h>
18 #include <linux/delay.h>
19 #include <linux/jiffies.h>
20 #include <asm/io.h>
21 
22 #include <scsi/scsi.h>
23 #include <scsi/scsi_cmnd.h>
24 #include <scsi/scsi_device.h>
25 #include <scsi/scsi_host.h>
26 
27 
28 static void ppa_reset_pulse(unsigned int base);
29 
30 typedef struct {
31  struct pardevice *dev; /* Parport device entry */
32  int base; /* Actual port address */
33  int mode; /* Transfer mode */
34  struct scsi_cmnd *cur_cmd; /* Current queued command */
35  struct delayed_work ppa_tq; /* Polling interrupt stuff */
36  unsigned long jstart; /* Jiffies at start */
37  unsigned long recon_tmo; /* How many usecs to wait for reconnection (6th bit) */
38  unsigned int failed:1; /* Failure flag */
39  unsigned wanted:1; /* Parport sharing busy flag */
41  struct Scsi_Host *host;
42  struct list_head list;
43 } ppa_struct;
44 
45 #include "ppa.h"
46 
47 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
48 {
49  return *(ppa_struct **)&host->hostdata;
50 }
51 
52 static DEFINE_SPINLOCK(arbitration_lock);
53 
54 static void got_it(ppa_struct *dev)
55 {
56  dev->base = dev->dev->port->base;
57  if (dev->cur_cmd)
58  dev->cur_cmd->SCp.phase = 1;
59  else
60  wake_up(dev->waiting);
61 }
62 
63 static void ppa_wakeup(void *ref)
64 {
65  ppa_struct *dev = (ppa_struct *) ref;
66  unsigned long flags;
67 
68  spin_lock_irqsave(&arbitration_lock, flags);
69  if (dev->wanted) {
70  parport_claim(dev->dev);
71  got_it(dev);
72  dev->wanted = 0;
73  }
74  spin_unlock_irqrestore(&arbitration_lock, flags);
75  return;
76 }
77 
78 static int ppa_pb_claim(ppa_struct *dev)
79 {
80  unsigned long flags;
81  int res = 1;
82  spin_lock_irqsave(&arbitration_lock, flags);
83  if (parport_claim(dev->dev) == 0) {
84  got_it(dev);
85  res = 0;
86  }
87  dev->wanted = res;
88  spin_unlock_irqrestore(&arbitration_lock, flags);
89  return res;
90 }
91 
92 static void ppa_pb_dismiss(ppa_struct *dev)
93 {
94  unsigned long flags;
95  int wanted;
96  spin_lock_irqsave(&arbitration_lock, flags);
97  wanted = dev->wanted;
98  dev->wanted = 0;
99  spin_unlock_irqrestore(&arbitration_lock, flags);
100  if (!wanted)
101  parport_release(dev->dev);
102 }
103 
104 static inline void ppa_pb_release(ppa_struct *dev)
105 {
106  parport_release(dev->dev);
107 }
108 
109 /*
110  * Start of Chipset kludges
111  */
112 
113 /* This is to give the ppa driver a way to modify the timings (and other
114  * parameters) by writing to the /proc/scsi/ppa/0 file.
115  * Very simple method really... (To simple, no error checking :( )
116  * Reason: Kernel hackers HATE having to unload and reload modules for
117  * testing...
118  * Also gives a method to use a script to obtain optimum timings (TODO)
119  */
120 
121 static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
122 {
123  unsigned long x;
124 
125  if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
126  x = simple_strtoul(buffer + 5, NULL, 0);
127  dev->mode = x;
128  return length;
129  }
130  if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
131  x = simple_strtoul(buffer + 10, NULL, 0);
132  dev->recon_tmo = x;
133  printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
134  return length;
135  }
136  printk(KERN_WARNING "ppa /proc: invalid variable\n");
137  return -EINVAL;
138 }
139 
140 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
141 {
142  int len = 0;
143  ppa_struct *dev = ppa_dev(host);
144 
145  if (inout)
146  return ppa_proc_write(dev, buffer, length);
147 
148  len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
149  len +=
150  sprintf(buffer + len, "Parport : %s\n",
151  dev->dev->port->name);
152  len +=
153  sprintf(buffer + len, "Mode : %s\n",
154  PPA_MODE_STRING[dev->mode]);
155 #if PPA_DEBUG > 0
156  len +=
157  sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
158 #endif
159 
160  /* Request for beyond end of buffer */
161  if (offset > length)
162  return 0;
163 
164  *start = buffer + offset;
165  len -= offset;
166  if (len > length)
167  len = length;
168  return len;
169 }
170 
171 static int device_check(ppa_struct *dev);
172 
173 #if PPA_DEBUG > 0
174 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
175  y, __func__, __LINE__); ppa_fail_func(x,y);
176 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
177 #else
178 static inline void ppa_fail(ppa_struct *dev, int error_code)
179 #endif
180 {
181  /* If we fail a device then we trash status / message bytes */
182  if (dev->cur_cmd) {
183  dev->cur_cmd->result = error_code << 16;
184  dev->failed = 1;
185  }
186 }
187 
188 /*
189  * Wait for the high bit to be set.
190  *
191  * In principle, this could be tied to an interrupt, but the adapter
192  * doesn't appear to be designed to support interrupts. We spin on
193  * the 0x80 ready bit.
194  */
195 static unsigned char ppa_wait(ppa_struct *dev)
196 {
197  int k;
198  unsigned short ppb = dev->base;
199  unsigned char r;
200 
201  k = PPA_SPIN_TMO;
202  /* Wait for bit 6 and 7 - PJC */
203  for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
204  udelay(1);
205  r = r_str(ppb);
206  }
207 
208  /*
209  * return some status information.
210  * Semantics: 0xc0 = ZIP wants more data
211  * 0xd0 = ZIP wants to send more data
212  * 0xe0 = ZIP is expecting SCSI command data
213  * 0xf0 = end of transfer, ZIP is sending status
214  */
215  if (k)
216  return (r & 0xf0);
217 
218  /* Counter expired - Time out occurred */
219  ppa_fail(dev, DID_TIME_OUT);
220  printk(KERN_WARNING "ppa timeout in ppa_wait\n");
221  return 0; /* command timed out */
222 }
223 
224 /*
225  * Clear EPP Timeout Bit
226  */
227 static inline void epp_reset(unsigned short ppb)
228 {
229  int i;
230 
231  i = r_str(ppb);
232  w_str(ppb, i);
233  w_str(ppb, i & 0xfe);
234 }
235 
236 /*
237  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
238  */
239 static inline void ecp_sync(ppa_struct *dev)
240 {
241  int i, ppb_hi = dev->dev->port->base_hi;
242 
243  if (ppb_hi == 0)
244  return;
245 
246  if ((r_ecr(ppb_hi) & 0xe0) == 0x60) { /* mode 011 == ECP fifo mode */
247  for (i = 0; i < 100; i++) {
248  if (r_ecr(ppb_hi) & 0x01)
249  return;
250  udelay(5);
251  }
252  printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
253  }
254 }
255 
256 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
257 {
258  int i;
259 
260  for (i = len; i; i--) {
261  w_dtr(base, *buffer++);
262  w_ctr(base, 0xe);
263  w_ctr(base, 0xc);
264  }
265  return 1; /* All went well - we hope! */
266 }
267 
268 static int ppa_byte_in(unsigned short base, char *buffer, int len)
269 {
270  int i;
271 
272  for (i = len; i; i--) {
273  *buffer++ = r_dtr(base);
274  w_ctr(base, 0x27);
275  w_ctr(base, 0x25);
276  }
277  return 1; /* All went well - we hope! */
278 }
279 
280 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
281 {
282  for (; len; len--) {
283  unsigned char h;
284 
285  w_ctr(base, 0x4);
286  h = r_str(base) & 0xf0;
287  w_ctr(base, 0x6);
288  *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
289  }
290  return 1; /* All went well - we hope! */
291 }
292 
293 static int ppa_out(ppa_struct *dev, char *buffer, int len)
294 {
295  int r;
296  unsigned short ppb = dev->base;
297 
298  r = ppa_wait(dev);
299 
300  if ((r & 0x50) != 0x40) {
301  ppa_fail(dev, DID_ERROR);
302  return 0;
303  }
304  switch (dev->mode) {
305  case PPA_NIBBLE:
306  case PPA_PS2:
307  /* 8 bit output, with a loop */
308  r = ppa_byte_out(ppb, buffer, len);
309  break;
310 
311  case PPA_EPP_32:
312  case PPA_EPP_16:
313  case PPA_EPP_8:
314  epp_reset(ppb);
315  w_ctr(ppb, 0x4);
316 #ifdef CONFIG_SCSI_IZIP_EPP16
317  if (!(((long) buffer | len) & 0x01))
318  outsw(ppb + 4, buffer, len >> 1);
319 #else
320  if (!(((long) buffer | len) & 0x03))
321  outsl(ppb + 4, buffer, len >> 2);
322 #endif
323  else
324  outsb(ppb + 4, buffer, len);
325  w_ctr(ppb, 0xc);
326  r = !(r_str(ppb) & 0x01);
327  w_ctr(ppb, 0xc);
328  ecp_sync(dev);
329  break;
330 
331  default:
332  printk(KERN_ERR "PPA: bug in ppa_out()\n");
333  r = 0;
334  }
335  return r;
336 }
337 
338 static int ppa_in(ppa_struct *dev, char *buffer, int len)
339 {
340  int r;
341  unsigned short ppb = dev->base;
342 
343  r = ppa_wait(dev);
344 
345  if ((r & 0x50) != 0x50) {
346  ppa_fail(dev, DID_ERROR);
347  return 0;
348  }
349  switch (dev->mode) {
350  case PPA_NIBBLE:
351  /* 4 bit input, with a loop */
352  r = ppa_nibble_in(ppb, buffer, len);
353  w_ctr(ppb, 0xc);
354  break;
355 
356  case PPA_PS2:
357  /* 8 bit input, with a loop */
358  w_ctr(ppb, 0x25);
359  r = ppa_byte_in(ppb, buffer, len);
360  w_ctr(ppb, 0x4);
361  w_ctr(ppb, 0xc);
362  break;
363 
364  case PPA_EPP_32:
365  case PPA_EPP_16:
366  case PPA_EPP_8:
367  epp_reset(ppb);
368  w_ctr(ppb, 0x24);
369 #ifdef CONFIG_SCSI_IZIP_EPP16
370  if (!(((long) buffer | len) & 0x01))
371  insw(ppb + 4, buffer, len >> 1);
372 #else
373  if (!(((long) buffer | len) & 0x03))
374  insl(ppb + 4, buffer, len >> 2);
375 #endif
376  else
377  insb(ppb + 4, buffer, len);
378  w_ctr(ppb, 0x2c);
379  r = !(r_str(ppb) & 0x01);
380  w_ctr(ppb, 0x2c);
381  ecp_sync(dev);
382  break;
383 
384  default:
385  printk(KERN_ERR "PPA: bug in ppa_ins()\n");
386  r = 0;
387  break;
388  }
389  return r;
390 }
391 
392 /* end of ppa_io.h */
393 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
394 {
395  w_dtr(ppb, b);
396  w_ctr(ppb, 0xc);
397  w_ctr(ppb, 0xe);
398  w_ctr(ppb, 0xc);
399  w_ctr(ppb, 0x4);
400  w_ctr(ppb, 0xc);
401 }
402 
403 static void ppa_disconnect(ppa_struct *dev)
404 {
405  unsigned short ppb = dev->base;
406 
407  ppa_d_pulse(ppb, 0);
408  ppa_d_pulse(ppb, 0x3c);
409  ppa_d_pulse(ppb, 0x20);
410  ppa_d_pulse(ppb, 0xf);
411 }
412 
413 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
414 {
415  w_dtr(ppb, b);
416  w_ctr(ppb, 0x4);
417  w_ctr(ppb, 0x6);
418  w_ctr(ppb, 0x4);
419  w_ctr(ppb, 0xc);
420 }
421 
422 static inline void ppa_connect(ppa_struct *dev, int flag)
423 {
424  unsigned short ppb = dev->base;
425 
426  ppa_c_pulse(ppb, 0);
427  ppa_c_pulse(ppb, 0x3c);
428  ppa_c_pulse(ppb, 0x20);
429  if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
430  ppa_c_pulse(ppb, 0xcf);
431  else
432  ppa_c_pulse(ppb, 0x8f);
433 }
434 
435 static int ppa_select(ppa_struct *dev, int target)
436 {
437  int k;
438  unsigned short ppb = dev->base;
439 
440  /*
441  * Bit 6 (0x40) is the device selected bit.
442  * First we must wait till the current device goes off line...
443  */
444  k = PPA_SELECT_TMO;
445  do {
446  k--;
447  udelay(1);
448  } while ((r_str(ppb) & 0x40) && (k));
449  if (!k)
450  return 0;
451 
452  w_dtr(ppb, (1 << target));
453  w_ctr(ppb, 0xe);
454  w_ctr(ppb, 0xc);
455  w_dtr(ppb, 0x80); /* This is NOT the initator */
456  w_ctr(ppb, 0x8);
457 
458  k = PPA_SELECT_TMO;
459  do {
460  k--;
461  udelay(1);
462  }
463  while (!(r_str(ppb) & 0x40) && (k));
464  if (!k)
465  return 0;
466 
467  return 1;
468 }
469 
470 /*
471  * This is based on a trace of what the Iomega DOS 'guest' driver does.
472  * I've tried several different kinds of parallel ports with guest and
473  * coded this to react in the same ways that it does.
474  *
475  * The return value from this function is just a hint about where the
476  * handshaking failed.
477  *
478  */
479 static int ppa_init(ppa_struct *dev)
480 {
481  int retv;
482  unsigned short ppb = dev->base;
483 
484  ppa_disconnect(dev);
485  ppa_connect(dev, CONNECT_NORMAL);
486 
487  retv = 2; /* Failed */
488 
489  w_ctr(ppb, 0xe);
490  if ((r_str(ppb) & 0x08) == 0x08)
491  retv--;
492 
493  w_ctr(ppb, 0xc);
494  if ((r_str(ppb) & 0x08) == 0x00)
495  retv--;
496 
497  if (!retv)
498  ppa_reset_pulse(ppb);
499  udelay(1000); /* Allow devices to settle down */
500  ppa_disconnect(dev);
501  udelay(1000); /* Another delay to allow devices to settle */
502 
503  if (retv)
504  return -EIO;
505 
506  return device_check(dev);
507 }
508 
509 static inline int ppa_send_command(struct scsi_cmnd *cmd)
510 {
511  ppa_struct *dev = ppa_dev(cmd->device->host);
512  int k;
513 
514  w_ctr(dev->base, 0x0c);
515 
516  for (k = 0; k < cmd->cmd_len; k++)
517  if (!ppa_out(dev, &cmd->cmnd[k], 1))
518  return 0;
519  return 1;
520 }
521 
522 /*
523  * The bulk flag enables some optimisations in the data transfer loops,
524  * it should be true for any command that transfers data in integral
525  * numbers of sectors.
526  *
527  * The driver appears to remain stable if we speed up the parallel port
528  * i/o in this function, but not elsewhere.
529  */
530 static int ppa_completion(struct scsi_cmnd *cmd)
531 {
532  /* Return codes:
533  * -1 Error
534  * 0 Told to schedule
535  * 1 Finished data transfer
536  */
537  ppa_struct *dev = ppa_dev(cmd->device->host);
538  unsigned short ppb = dev->base;
539  unsigned long start_jiffies = jiffies;
540 
541  unsigned char r, v;
542  int fast, bulk, status;
543 
544  v = cmd->cmnd[0];
545  bulk = ((v == READ_6) ||
546  (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
547 
548  /*
549  * We only get here if the drive is ready to comunicate,
550  * hence no need for a full ppa_wait.
551  */
552  r = (r_str(ppb) & 0xf0);
553 
554  while (r != (unsigned char) 0xf0) {
555  /*
556  * If we have been running for more than a full timer tick
557  * then take a rest.
558  */
559  if (time_after(jiffies, start_jiffies + 1))
560  return 0;
561 
562  if ((cmd->SCp.this_residual <= 0)) {
563  ppa_fail(dev, DID_ERROR);
564  return -1; /* ERROR_RETURN */
565  }
566 
567  /* On some hardware we have SCSI disconnected (6th bit low)
568  * for about 100usecs. It is too expensive to wait a
569  * tick on every loop so we busy wait for no more than
570  * 500usecs to give the drive a chance first. We do not
571  * change things for "normal" hardware since generally
572  * the 6th bit is always high.
573  * This makes the CPU load higher on some hardware
574  * but otherwise we can not get more than 50K/secs
575  * on this problem hardware.
576  */
577  if ((r & 0xc0) != 0xc0) {
578  /* Wait for reconnection should be no more than
579  * jiffy/2 = 5ms = 5000 loops
580  */
581  unsigned long k = dev->recon_tmo;
582  for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
583  k--)
584  udelay(1);
585 
586  if (!k)
587  return 0;
588  }
589 
590  /* determine if we should use burst I/O */
591  fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
592  ? PPA_BURST_SIZE : 1;
593 
594  if (r == (unsigned char) 0xc0)
595  status = ppa_out(dev, cmd->SCp.ptr, fast);
596  else
597  status = ppa_in(dev, cmd->SCp.ptr, fast);
598 
599  cmd->SCp.ptr += fast;
600  cmd->SCp.this_residual -= fast;
601 
602  if (!status) {
603  ppa_fail(dev, DID_BUS_BUSY);
604  return -1; /* ERROR_RETURN */
605  }
606  if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
607  /* if scatter/gather, advance to the next segment */
608  if (cmd->SCp.buffers_residual--) {
609  cmd->SCp.buffer++;
610  cmd->SCp.this_residual =
611  cmd->SCp.buffer->length;
612  cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
613  }
614  }
615  /* Now check to see if the drive is ready to comunicate */
616  r = (r_str(ppb) & 0xf0);
617  /* If not, drop back down to the scheduler and wait a timer tick */
618  if (!(r & 0x80))
619  return 0;
620  }
621  return 1; /* FINISH_RETURN */
622 }
623 
624 /*
625  * Since the PPA itself doesn't generate interrupts, we use
626  * the scheduler's task queue to generate a stream of call-backs and
627  * complete the request when the drive is ready.
628  */
629 static void ppa_interrupt(struct work_struct *work)
630 {
631  ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
632  struct scsi_cmnd *cmd = dev->cur_cmd;
633 
634  if (!cmd) {
635  printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
636  return;
637  }
638  if (ppa_engine(dev, cmd)) {
639  schedule_delayed_work(&dev->ppa_tq, 1);
640  return;
641  }
642  /* Command must of completed hence it is safe to let go... */
643 #if PPA_DEBUG > 0
644  switch ((cmd->result >> 16) & 0xff) {
645  case DID_OK:
646  break;
647  case DID_NO_CONNECT:
648  printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
649  break;
650  case DID_BUS_BUSY:
651  printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
652  break;
653  case DID_TIME_OUT:
654  printk(KERN_DEBUG "ppa: unknown timeout\n");
655  break;
656  case DID_ABORT:
657  printk(KERN_DEBUG "ppa: told to abort\n");
658  break;
659  case DID_PARITY:
660  printk(KERN_DEBUG "ppa: parity error (???)\n");
661  break;
662  case DID_ERROR:
663  printk(KERN_DEBUG "ppa: internal driver error\n");
664  break;
665  case DID_RESET:
666  printk(KERN_DEBUG "ppa: told to reset device\n");
667  break;
668  case DID_BAD_INTR:
669  printk(KERN_WARNING "ppa: bad interrupt (???)\n");
670  break;
671  default:
672  printk(KERN_WARNING "ppa: bad return code (%02x)\n",
673  (cmd->result >> 16) & 0xff);
674  }
675 #endif
676 
677  if (cmd->SCp.phase > 1)
678  ppa_disconnect(dev);
679 
680  ppa_pb_dismiss(dev);
681 
682  dev->cur_cmd = NULL;
683 
684  cmd->scsi_done(cmd);
685 }
686 
687 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
688 {
689  unsigned short ppb = dev->base;
690  unsigned char l = 0, h = 0;
691  int retv;
692 
693  /* First check for any errors that may of occurred
694  * Here we check for internal errors
695  */
696  if (dev->failed)
697  return 0;
698 
699  switch (cmd->SCp.phase) {
700  case 0: /* Phase 0 - Waiting for parport */
701  if (time_after(jiffies, dev->jstart + HZ)) {
702  /*
703  * We waited more than a second
704  * for parport to call us
705  */
706  ppa_fail(dev, DID_BUS_BUSY);
707  return 0;
708  }
709  return 1; /* wait until ppa_wakeup claims parport */
710  case 1: /* Phase 1 - Connected */
711  { /* Perform a sanity check for cable unplugged */
712  int retv = 2; /* Failed */
713 
714  ppa_connect(dev, CONNECT_EPP_MAYBE);
715 
716  w_ctr(ppb, 0xe);
717  if ((r_str(ppb) & 0x08) == 0x08)
718  retv--;
719 
720  w_ctr(ppb, 0xc);
721  if ((r_str(ppb) & 0x08) == 0x00)
722  retv--;
723 
724  if (retv) {
725  if (time_after(jiffies, dev->jstart + (1 * HZ))) {
726  printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
727  ppa_fail(dev, DID_BUS_BUSY);
728  return 0;
729  } else {
730  ppa_disconnect(dev);
731  return 1; /* Try again in a jiffy */
732  }
733  }
734  cmd->SCp.phase++;
735  }
736 
737  case 2: /* Phase 2 - We are now talking to the scsi bus */
738  if (!ppa_select(dev, scmd_id(cmd))) {
739  ppa_fail(dev, DID_NO_CONNECT);
740  return 0;
741  }
742  cmd->SCp.phase++;
743 
744  case 3: /* Phase 3 - Ready to accept a command */
745  w_ctr(ppb, 0x0c);
746  if (!(r_str(ppb) & 0x80))
747  return 1;
748 
749  if (!ppa_send_command(cmd))
750  return 0;
751  cmd->SCp.phase++;
752 
753  case 4: /* Phase 4 - Setup scatter/gather buffers */
754  if (scsi_bufflen(cmd)) {
755  cmd->SCp.buffer = scsi_sglist(cmd);
756  cmd->SCp.this_residual = cmd->SCp.buffer->length;
757  cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
758  } else {
759  cmd->SCp.buffer = NULL;
760  cmd->SCp.this_residual = 0;
761  cmd->SCp.ptr = NULL;
762  }
763  cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
764  cmd->SCp.phase++;
765 
766  case 5: /* Phase 5 - Data transfer stage */
767  w_ctr(ppb, 0x0c);
768  if (!(r_str(ppb) & 0x80))
769  return 1;
770 
771  retv = ppa_completion(cmd);
772  if (retv == -1)
773  return 0;
774  if (retv == 0)
775  return 1;
776  cmd->SCp.phase++;
777 
778  case 6: /* Phase 6 - Read status/message */
779  cmd->result = DID_OK << 16;
780  /* Check for data overrun */
781  if (ppa_wait(dev) != (unsigned char) 0xf0) {
782  ppa_fail(dev, DID_ERROR);
783  return 0;
784  }
785  if (ppa_in(dev, &l, 1)) { /* read status byte */
786  /* Check for optional message byte */
787  if (ppa_wait(dev) == (unsigned char) 0xf0)
788  ppa_in(dev, &h, 1);
789  cmd->result =
790  (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
791  }
792  return 0; /* Finished */
793  break;
794 
795  default:
796  printk(KERN_ERR "ppa: Invalid scsi phase\n");
797  }
798  return 0;
799 }
800 
801 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
802  void (*done) (struct scsi_cmnd *))
803 {
804  ppa_struct *dev = ppa_dev(cmd->device->host);
805 
806  if (dev->cur_cmd) {
807  printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
808  return 0;
809  }
810  dev->failed = 0;
811  dev->jstart = jiffies;
812  dev->cur_cmd = cmd;
813  cmd->scsi_done = done;
814  cmd->result = DID_ERROR << 16; /* default return code */
815  cmd->SCp.phase = 0; /* bus free */
816 
817  schedule_delayed_work(&dev->ppa_tq, 0);
818 
819  ppa_pb_claim(dev);
820 
821  return 0;
822 }
823 
824 static DEF_SCSI_QCMD(ppa_queuecommand)
825 
826 /*
827  * Apparently the disk->capacity attribute is off by 1 sector
828  * for all disk drives. We add the one here, but it should really
829  * be done in sd.c. Even if it gets fixed there, this will still
830  * work.
831  */
832 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
833  sector_t capacity, int ip[])
834 {
835  ip[0] = 0x40;
836  ip[1] = 0x20;
837  ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
838  if (ip[2] > 1024) {
839  ip[0] = 0xff;
840  ip[1] = 0x3f;
841  ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
842  if (ip[2] > 1023)
843  ip[2] = 1023;
844  }
845  return 0;
846 }
847 
848 static int ppa_abort(struct scsi_cmnd *cmd)
849 {
850  ppa_struct *dev = ppa_dev(cmd->device->host);
851  /*
852  * There is no method for aborting commands since Iomega
853  * have tied the SCSI_MESSAGE line high in the interface
854  */
855 
856  switch (cmd->SCp.phase) {
857  case 0: /* Do not have access to parport */
858  case 1: /* Have not connected to interface */
859  dev->cur_cmd = NULL; /* Forget the problem */
860  return SUCCESS;
861  break;
862  default: /* SCSI command sent, can not abort */
863  return FAILED;
864  break;
865  }
866 }
867 
868 static void ppa_reset_pulse(unsigned int base)
869 {
870  w_dtr(base, 0x40);
871  w_ctr(base, 0x8);
872  udelay(30);
873  w_ctr(base, 0xc);
874 }
875 
876 static int ppa_reset(struct scsi_cmnd *cmd)
877 {
878  ppa_struct *dev = ppa_dev(cmd->device->host);
879 
880  if (cmd->SCp.phase)
881  ppa_disconnect(dev);
882  dev->cur_cmd = NULL; /* Forget the problem */
883 
884  ppa_connect(dev, CONNECT_NORMAL);
885  ppa_reset_pulse(dev->base);
886  mdelay(1); /* device settle delay */
887  ppa_disconnect(dev);
888  mdelay(1); /* device settle delay */
889  return SUCCESS;
890 }
891 
892 static int device_check(ppa_struct *dev)
893 {
894  /* This routine looks for a device and then attempts to use EPP
895  to send a command. If all goes as planned then EPP is available. */
896 
897  static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
898  int loop, old_mode, status, k, ppb = dev->base;
899  unsigned char l;
900 
901  old_mode = dev->mode;
902  for (loop = 0; loop < 8; loop++) {
903  /* Attempt to use EPP for Test Unit Ready */
904  if ((ppb & 0x0007) == 0x0000)
905  dev->mode = PPA_EPP_32;
906 
907 second_pass:
908  ppa_connect(dev, CONNECT_EPP_MAYBE);
909  /* Select SCSI device */
910  if (!ppa_select(dev, loop)) {
911  ppa_disconnect(dev);
912  continue;
913  }
914  printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
915  loop, PPA_MODE_STRING[dev->mode]);
916 
917  /* Send SCSI command */
918  status = 1;
919  w_ctr(ppb, 0x0c);
920  for (l = 0; (l < 6) && (status); l++)
921  status = ppa_out(dev, cmd, 1);
922 
923  if (!status) {
924  ppa_disconnect(dev);
925  ppa_connect(dev, CONNECT_EPP_MAYBE);
926  w_dtr(ppb, 0x40);
927  w_ctr(ppb, 0x08);
928  udelay(30);
929  w_ctr(ppb, 0x0c);
930  udelay(1000);
931  ppa_disconnect(dev);
932  udelay(1000);
933  if (dev->mode == PPA_EPP_32) {
934  dev->mode = old_mode;
935  goto second_pass;
936  }
937  return -EIO;
938  }
939  w_ctr(ppb, 0x0c);
940  k = 1000000; /* 1 Second */
941  do {
942  l = r_str(ppb);
943  k--;
944  udelay(1);
945  } while (!(l & 0x80) && (k));
946 
947  l &= 0xf0;
948 
949  if (l != 0xf0) {
950  ppa_disconnect(dev);
951  ppa_connect(dev, CONNECT_EPP_MAYBE);
952  ppa_reset_pulse(ppb);
953  udelay(1000);
954  ppa_disconnect(dev);
955  udelay(1000);
956  if (dev->mode == PPA_EPP_32) {
957  dev->mode = old_mode;
958  goto second_pass;
959  }
960  return -EIO;
961  }
962  ppa_disconnect(dev);
963  printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
964  loop, PPA_MODE_STRING[dev->mode]);
965  ppa_connect(dev, CONNECT_EPP_MAYBE);
966  ppa_reset_pulse(ppb);
967  udelay(1000);
968  ppa_disconnect(dev);
969  udelay(1000);
970  return 0;
971  }
972  return -ENODEV;
973 }
974 
975 static int ppa_adjust_queue(struct scsi_device *device)
976 {
977  blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
978  return 0;
979 }
980 
981 static struct scsi_host_template ppa_template = {
982  .module = THIS_MODULE,
983  .proc_name = "ppa",
984  .proc_info = ppa_proc_info,
985  .name = "Iomega VPI0 (ppa) interface",
986  .queuecommand = ppa_queuecommand,
987  .eh_abort_handler = ppa_abort,
988  .eh_bus_reset_handler = ppa_reset,
989  .eh_host_reset_handler = ppa_reset,
990  .bios_param = ppa_biosparam,
991  .this_id = -1,
992  .sg_tablesize = SG_ALL,
993  .cmd_per_lun = 1,
994  .use_clustering = ENABLE_CLUSTERING,
995  .can_queue = 1,
996  .slave_alloc = ppa_adjust_queue,
997 };
998 
999 /***************************************************************************
1000  * Parallel port probing routines *
1001  ***************************************************************************/
1002 
1003 static LIST_HEAD(ppa_hosts);
1004 
1005 static int __ppa_attach(struct parport *pb)
1006 {
1007  struct Scsi_Host *host;
1009  DEFINE_WAIT(wait);
1010  ppa_struct *dev;
1011  int ports;
1012  int modes, ppb, ppb_hi;
1013  int err = -ENOMEM;
1014 
1015  dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1016  if (!dev)
1017  return -ENOMEM;
1018  dev->base = -1;
1019  dev->mode = PPA_AUTODETECT;
1020  dev->recon_tmo = PPA_RECON_TMO;
1021  init_waitqueue_head(&waiting);
1022  dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1023  NULL, 0, dev);
1024 
1025  if (!dev->dev)
1026  goto out;
1027 
1028  /* Claim the bus so it remembers what we do to the control
1029  * registers. [ CTR and ECP ]
1030  */
1031  err = -EBUSY;
1032  dev->waiting = &waiting;
1034  if (ppa_pb_claim(dev))
1035  schedule_timeout(3 * HZ);
1036  if (dev->wanted) {
1037  printk(KERN_ERR "ppa%d: failed to claim parport because "
1038  "a pardevice is owning the port for too long "
1039  "time!\n", pb->number);
1040  ppa_pb_dismiss(dev);
1041  dev->waiting = NULL;
1042  finish_wait(&waiting, &wait);
1043  goto out1;
1044  }
1045  dev->waiting = NULL;
1046  finish_wait(&waiting, &wait);
1047  ppb = dev->base = dev->dev->port->base;
1048  ppb_hi = dev->dev->port->base_hi;
1049  w_ctr(ppb, 0x0c);
1050  modes = dev->dev->port->modes;
1051 
1052  /* Mode detection works up the chain of speed
1053  * This avoids a nasty if-then-else-if-... tree
1054  */
1055  dev->mode = PPA_NIBBLE;
1056 
1057  if (modes & PARPORT_MODE_TRISTATE)
1058  dev->mode = PPA_PS2;
1059 
1060  if (modes & PARPORT_MODE_ECP) {
1061  w_ecr(ppb_hi, 0x20);
1062  dev->mode = PPA_PS2;
1063  }
1064  if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1065  w_ecr(ppb_hi, 0x80);
1066 
1067  /* Done configuration */
1068 
1069  err = ppa_init(dev);
1070  ppa_pb_release(dev);
1071 
1072  if (err)
1073  goto out1;
1074 
1075  /* now the glue ... */
1076  if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1077  ports = 3;
1078  else
1079  ports = 8;
1080 
1081  INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1082 
1083  err = -ENOMEM;
1084  host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1085  if (!host)
1086  goto out1;
1087  host->io_port = pb->base;
1088  host->n_io_port = ports;
1089  host->dma_channel = -1;
1090  host->unique_id = pb->number;
1091  *(ppa_struct **)&host->hostdata = dev;
1092  dev->host = host;
1093  list_add_tail(&dev->list, &ppa_hosts);
1094  err = scsi_add_host(host, NULL);
1095  if (err)
1096  goto out2;
1097  scsi_scan_host(host);
1098  return 0;
1099 out2:
1100  list_del_init(&dev->list);
1101  scsi_host_put(host);
1102 out1:
1104 out:
1105  kfree(dev);
1106  return err;
1107 }
1108 
1109 static void ppa_attach(struct parport *pb)
1110 {
1111  __ppa_attach(pb);
1112 }
1113 
1114 static void ppa_detach(struct parport *pb)
1115 {
1116  ppa_struct *dev;
1117  list_for_each_entry(dev, &ppa_hosts, list) {
1118  if (dev->dev->port == pb) {
1119  list_del_init(&dev->list);
1120  scsi_remove_host(dev->host);
1121  scsi_host_put(dev->host);
1123  kfree(dev);
1124  break;
1125  }
1126  }
1127 }
1128 
1129 static struct parport_driver ppa_driver = {
1130  .name = "ppa",
1131  .attach = ppa_attach,
1132  .detach = ppa_detach,
1133 };
1134 
1135 static int __init ppa_driver_init(void)
1136 {
1137  printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1138  return parport_register_driver(&ppa_driver);
1139 }
1140 
1141 static void __exit ppa_driver_exit(void)
1142 {
1143  parport_unregister_driver(&ppa_driver);
1144 }
1145 
1146 module_init(ppa_driver_init);
1147 module_exit(ppa_driver_exit);
1148 MODULE_LICENSE("GPL");