Merge branch 'for-jeff' of git://electric-eye.fr.zoreil.com/home/romieu/linux-2.6
[linux-2.6] / drivers / scsi / ppa.c
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, grant@torque.net,
7  * under the terms of the GNU General Public License.
8  * 
9  * Current Maintainer: David Campbell (Perth, Western Australia, GMT+0800)
10  *                     campbell@torque.net
11  */
12
13 #include <linux/config.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/blkdev.h>
18 #include <linux/parport.h>
19 #include <linux/workqueue.h>
20 #include <linux/delay.h>
21 #include <asm/io.h>
22
23 #include <scsi/scsi.h>
24 #include <scsi/scsi_cmnd.h>
25 #include <scsi/scsi_device.h>
26 #include <scsi/scsi_host.h>
27
28
29 static void ppa_reset_pulse(unsigned int base);
30
31 typedef struct {
32         struct pardevice *dev;  /* Parport device entry         */
33         int base;               /* Actual port address          */
34         int mode;               /* Transfer mode                */
35         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
36         struct work_struct ppa_tq;      /* Polling interrupt stuff       */
37         unsigned long jstart;   /* Jiffies at start             */
38         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
39         unsigned int failed:1;  /* Failure flag                 */
40         unsigned wanted:1;      /* Parport sharing busy flag    */
41         wait_queue_head_t *waiting;
42         struct Scsi_Host *host;
43         struct list_head list;
44 } ppa_struct;
45
46 #include  "ppa.h"
47
48 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
49 {
50         return *(ppa_struct **)&host->hostdata;
51 }
52
53 static DEFINE_SPINLOCK(arbitration_lock);
54
55 static void got_it(ppa_struct *dev)
56 {
57         dev->base = dev->dev->port->base;
58         if (dev->cur_cmd)
59                 dev->cur_cmd->SCp.phase = 1;
60         else
61                 wake_up(dev->waiting);
62 }
63
64 static void ppa_wakeup(void *ref)
65 {
66         ppa_struct *dev = (ppa_struct *) ref;
67         unsigned long flags;
68
69         spin_lock_irqsave(&arbitration_lock, flags);
70         if (dev->wanted) {
71                 parport_claim(dev->dev);
72                 got_it(dev);
73                 dev->wanted = 0;
74         }
75         spin_unlock_irqrestore(&arbitration_lock, flags);
76         return;
77 }
78
79 static int ppa_pb_claim(ppa_struct *dev)
80 {
81         unsigned long flags;
82         int res = 1;
83         spin_lock_irqsave(&arbitration_lock, flags);
84         if (parport_claim(dev->dev) == 0) {
85                 got_it(dev);
86                 res = 0;
87         }
88         dev->wanted = res;
89         spin_unlock_irqrestore(&arbitration_lock, flags);
90         return res;
91 }
92
93 static void ppa_pb_dismiss(ppa_struct *dev)
94 {
95         unsigned long flags;
96         int wanted;
97         spin_lock_irqsave(&arbitration_lock, flags);
98         wanted = dev->wanted;
99         dev->wanted = 0;
100         spin_unlock_irqrestore(&arbitration_lock, flags);
101         if (!wanted)
102                 parport_release(dev->dev);
103 }
104
105 static inline void ppa_pb_release(ppa_struct *dev)
106 {
107         parport_release(dev->dev);
108 }
109
110 /*
111  * Start of Chipset kludges
112  */
113
114 /* This is to give the ppa driver a way to modify the timings (and other
115  * parameters) by writing to the /proc/scsi/ppa/0 file.
116  * Very simple method really... (To simple, no error checking :( )
117  * Reason: Kernel hackers HATE having to unload and reload modules for
118  * testing...
119  * Also gives a method to use a script to obtain optimum timings (TODO)
120  */
121
122 static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
123 {
124         unsigned long x;
125
126         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
127                 x = simple_strtoul(buffer + 5, NULL, 0);
128                 dev->mode = x;
129                 return length;
130         }
131         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
132                 x = simple_strtoul(buffer + 10, NULL, 0);
133                 dev->recon_tmo = x;
134                 printk("ppa: recon_tmo set to %ld\n", x);
135                 return length;
136         }
137         printk("ppa /proc: invalid variable\n");
138         return (-EINVAL);
139 }
140
141 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
142 {
143         int len = 0;
144         ppa_struct *dev = ppa_dev(host);
145
146         if (inout)
147                 return ppa_proc_write(dev, buffer, length);
148
149         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
150         len +=
151             sprintf(buffer + len, "Parport : %s\n",
152                     dev->dev->port->name);
153         len +=
154             sprintf(buffer + len, "Mode    : %s\n",
155                     PPA_MODE_STRING[dev->mode]);
156 #if PPA_DEBUG > 0
157         len +=
158             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
159 #endif
160
161         /* Request for beyond end of buffer */
162         if (offset > length)
163                 return 0;
164
165         *start = buffer + offset;
166         len -= offset;
167         if (len > length)
168                 len = length;
169         return len;
170 }
171
172 static int device_check(ppa_struct *dev);
173
174 #if PPA_DEBUG > 0
175 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
176            y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
177 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
178 #else
179 static inline void ppa_fail(ppa_struct *dev, int error_code)
180 #endif
181 {
182         /* If we fail a device then we trash status / message bytes */
183         if (dev->cur_cmd) {
184                 dev->cur_cmd->result = error_code << 16;
185                 dev->failed = 1;
186         }
187 }
188
189 /*
190  * Wait for the high bit to be set.
191  * 
192  * In principle, this could be tied to an interrupt, but the adapter
193  * doesn't appear to be designed to support interrupts.  We spin on
194  * the 0x80 ready bit. 
195  */
196 static unsigned char ppa_wait(ppa_struct *dev)
197 {
198         int k;
199         unsigned short ppb = dev->base;
200         unsigned char r;
201
202         k = PPA_SPIN_TMO;
203         /* Wait for bit 6 and 7 - PJC */
204         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
205                 udelay(1);
206                 r = r_str(ppb);
207         }
208
209         /*
210          * return some status information.
211          * Semantics: 0xc0 = ZIP wants more data
212          *            0xd0 = ZIP wants to send more data
213          *            0xe0 = ZIP is expecting SCSI command data
214          *            0xf0 = end of transfer, ZIP is sending status
215          */
216         if (k)
217                 return (r & 0xf0);
218
219         /* Counter expired - Time out occurred */
220         ppa_fail(dev, DID_TIME_OUT);
221         printk("ppa timeout in ppa_wait\n");
222         return 0;               /* command timed out */
223 }
224
225 /*
226  * Clear EPP Timeout Bit 
227  */
228 static inline void epp_reset(unsigned short ppb)
229 {
230         int i;
231
232         i = r_str(ppb);
233         w_str(ppb, i);
234         w_str(ppb, i & 0xfe);
235 }
236
237 /* 
238  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
239  */
240 static inline void ecp_sync(ppa_struct *dev)
241 {
242         int i, ppb_hi = dev->dev->port->base_hi;
243
244         if (ppb_hi == 0)
245                 return;
246
247         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
248                 for (i = 0; i < 100; i++) {
249                         if (r_ecr(ppb_hi) & 0x01)
250                                 return;
251                         udelay(5);
252                 }
253                 printk("ppa: ECP sync failed as data still present in FIFO.\n");
254         }
255 }
256
257 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
258 {
259         int i;
260
261         for (i = len; i; i--) {
262                 w_dtr(base, *buffer++);
263                 w_ctr(base, 0xe);
264                 w_ctr(base, 0xc);
265         }
266         return 1;               /* All went well - we hope! */
267 }
268
269 static int ppa_byte_in(unsigned short base, char *buffer, int len)
270 {
271         int i;
272
273         for (i = len; i; i--) {
274                 *buffer++ = r_dtr(base);
275                 w_ctr(base, 0x27);
276                 w_ctr(base, 0x25);
277         }
278         return 1;               /* All went well - we hope! */
279 }
280
281 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
282 {
283         for (; len; len--) {
284                 unsigned char h;
285
286                 w_ctr(base, 0x4);
287                 h = r_str(base) & 0xf0;
288                 w_ctr(base, 0x6);
289                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
290         }
291         return 1;               /* All went well - we hope! */
292 }
293
294 static int ppa_out(ppa_struct *dev, char *buffer, int len)
295 {
296         int r;
297         unsigned short ppb = dev->base;
298
299         r = ppa_wait(dev);
300
301         if ((r & 0x50) != 0x40) {
302                 ppa_fail(dev, DID_ERROR);
303                 return 0;
304         }
305         switch (dev->mode) {
306         case PPA_NIBBLE:
307         case PPA_PS2:
308                 /* 8 bit output, with a loop */
309                 r = ppa_byte_out(ppb, buffer, len);
310                 break;
311
312         case PPA_EPP_32:
313         case PPA_EPP_16:
314         case PPA_EPP_8:
315                 epp_reset(ppb);
316                 w_ctr(ppb, 0x4);
317 #ifdef CONFIG_SCSI_IZIP_EPP16
318                 if (!(((long) buffer | len) & 0x01))
319                         outsw(ppb + 4, buffer, len >> 1);
320 #else
321                 if (!(((long) buffer | len) & 0x03))
322                         outsl(ppb + 4, buffer, len >> 2);
323 #endif
324                 else
325                         outsb(ppb + 4, buffer, len);
326                 w_ctr(ppb, 0xc);
327                 r = !(r_str(ppb) & 0x01);
328                 w_ctr(ppb, 0xc);
329                 ecp_sync(dev);
330                 break;
331
332         default:
333                 printk("PPA: bug in ppa_out()\n");
334                 r = 0;
335         }
336         return r;
337 }
338
339 static int ppa_in(ppa_struct *dev, char *buffer, int len)
340 {
341         int r;
342         unsigned short ppb = dev->base;
343
344         r = ppa_wait(dev);
345
346         if ((r & 0x50) != 0x50) {
347                 ppa_fail(dev, DID_ERROR);
348                 return 0;
349         }
350         switch (dev->mode) {
351         case PPA_NIBBLE:
352                 /* 4 bit input, with a loop */
353                 r = ppa_nibble_in(ppb, buffer, len);
354                 w_ctr(ppb, 0xc);
355                 break;
356
357         case PPA_PS2:
358                 /* 8 bit input, with a loop */
359                 w_ctr(ppb, 0x25);
360                 r = ppa_byte_in(ppb, buffer, len);
361                 w_ctr(ppb, 0x4);
362                 w_ctr(ppb, 0xc);
363                 break;
364
365         case PPA_EPP_32:
366         case PPA_EPP_16:
367         case PPA_EPP_8:
368                 epp_reset(ppb);
369                 w_ctr(ppb, 0x24);
370 #ifdef CONFIG_SCSI_IZIP_EPP16
371                 if (!(((long) buffer | len) & 0x01))
372                         insw(ppb + 4, buffer, len >> 1);
373 #else
374                 if (!(((long) buffer | len) & 0x03))
375                         insl(ppb + 4, buffer, len >> 2);
376 #endif
377                 else
378                         insb(ppb + 4, buffer, len);
379                 w_ctr(ppb, 0x2c);
380                 r = !(r_str(ppb) & 0x01);
381                 w_ctr(ppb, 0x2c);
382                 ecp_sync(dev);
383                 break;
384
385         default:
386                 printk("PPA: bug in ppa_ins()\n");
387                 r = 0;
388                 break;
389         }
390         return r;
391 }
392
393 /* end of ppa_io.h */
394 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
395 {
396         w_dtr(ppb, b);
397         w_ctr(ppb, 0xc);
398         w_ctr(ppb, 0xe);
399         w_ctr(ppb, 0xc);
400         w_ctr(ppb, 0x4);
401         w_ctr(ppb, 0xc);
402 }
403
404 static void ppa_disconnect(ppa_struct *dev)
405 {
406         unsigned short ppb = dev->base;
407
408         ppa_d_pulse(ppb, 0);
409         ppa_d_pulse(ppb, 0x3c);
410         ppa_d_pulse(ppb, 0x20);
411         ppa_d_pulse(ppb, 0xf);
412 }
413
414 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
415 {
416         w_dtr(ppb, b);
417         w_ctr(ppb, 0x4);
418         w_ctr(ppb, 0x6);
419         w_ctr(ppb, 0x4);
420         w_ctr(ppb, 0xc);
421 }
422
423 static inline void ppa_connect(ppa_struct *dev, int flag)
424 {
425         unsigned short ppb = dev->base;
426
427         ppa_c_pulse(ppb, 0);
428         ppa_c_pulse(ppb, 0x3c);
429         ppa_c_pulse(ppb, 0x20);
430         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
431                 ppa_c_pulse(ppb, 0xcf);
432         else
433                 ppa_c_pulse(ppb, 0x8f);
434 }
435
436 static int ppa_select(ppa_struct *dev, int target)
437 {
438         int k;
439         unsigned short ppb = dev->base;
440
441         /*
442          * Bit 6 (0x40) is the device selected bit.
443          * First we must wait till the current device goes off line...
444          */
445         k = PPA_SELECT_TMO;
446         do {
447                 k--;
448                 udelay(1);
449         } while ((r_str(ppb) & 0x40) && (k));
450         if (!k)
451                 return 0;
452
453         w_dtr(ppb, (1 << target));
454         w_ctr(ppb, 0xe);
455         w_ctr(ppb, 0xc);
456         w_dtr(ppb, 0x80);       /* This is NOT the initator */
457         w_ctr(ppb, 0x8);
458
459         k = PPA_SELECT_TMO;
460         do {
461                 k--;
462                 udelay(1);
463         }
464         while (!(r_str(ppb) & 0x40) && (k));
465         if (!k)
466                 return 0;
467
468         return 1;
469 }
470
471 /* 
472  * This is based on a trace of what the Iomega DOS 'guest' driver does.
473  * I've tried several different kinds of parallel ports with guest and
474  * coded this to react in the same ways that it does.
475  * 
476  * The return value from this function is just a hint about where the
477  * handshaking failed.
478  * 
479  */
480 static int ppa_init(ppa_struct *dev)
481 {
482         int retv;
483         unsigned short ppb = dev->base;
484
485         ppa_disconnect(dev);
486         ppa_connect(dev, CONNECT_NORMAL);
487
488         retv = 2;               /* Failed */
489
490         w_ctr(ppb, 0xe);
491         if ((r_str(ppb) & 0x08) == 0x08)
492                 retv--;
493
494         w_ctr(ppb, 0xc);
495         if ((r_str(ppb) & 0x08) == 0x00)
496                 retv--;
497
498         if (!retv)
499                 ppa_reset_pulse(ppb);
500         udelay(1000);           /* Allow devices to settle down */
501         ppa_disconnect(dev);
502         udelay(1000);           /* Another delay to allow devices to settle */
503
504         if (retv)
505                 return -EIO;
506
507         return device_check(dev);
508 }
509
510 static inline int ppa_send_command(struct scsi_cmnd *cmd)
511 {
512         ppa_struct *dev = ppa_dev(cmd->device->host);
513         int k;
514
515         w_ctr(dev->base, 0x0c);
516
517         for (k = 0; k < cmd->cmd_len; k++)
518                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
519                         return 0;
520         return 1;
521 }
522
523 /*
524  * The bulk flag enables some optimisations in the data transfer loops,
525  * it should be true for any command that transfers data in integral
526  * numbers of sectors.
527  * 
528  * The driver appears to remain stable if we speed up the parallel port
529  * i/o in this function, but not elsewhere.
530  */
531 static int ppa_completion(struct scsi_cmnd *cmd)
532 {
533         /* Return codes:
534          * -1     Error
535          *  0     Told to schedule
536          *  1     Finished data transfer
537          */
538         ppa_struct *dev = ppa_dev(cmd->device->host);
539         unsigned short ppb = dev->base;
540         unsigned long start_jiffies = jiffies;
541
542         unsigned char r, v;
543         int fast, bulk, status;
544
545         v = cmd->cmnd[0];
546         bulk = ((v == READ_6) ||
547                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
548
549         /*
550          * We only get here if the drive is ready to comunicate,
551          * hence no need for a full ppa_wait.
552          */
553         r = (r_str(ppb) & 0xf0);
554
555         while (r != (unsigned char) 0xf0) {
556                 /*
557                  * If we have been running for more than a full timer tick
558                  * then take a rest.
559                  */
560                 if (time_after(jiffies, start_jiffies + 1))
561                         return 0;
562
563                 if ((cmd->SCp.this_residual <= 0)) {
564                         ppa_fail(dev, DID_ERROR);
565                         return -1;      /* ERROR_RETURN */
566                 }
567
568                 /* On some hardware we have SCSI disconnected (6th bit low)
569                  * for about 100usecs. It is too expensive to wait a 
570                  * tick on every loop so we busy wait for no more than
571                  * 500usecs to give the drive a chance first. We do not 
572                  * change things for "normal" hardware since generally 
573                  * the 6th bit is always high.
574                  * This makes the CPU load higher on some hardware 
575                  * but otherwise we can not get more than 50K/secs 
576                  * on this problem hardware.
577                  */
578                 if ((r & 0xc0) != 0xc0) {
579                         /* Wait for reconnection should be no more than 
580                          * jiffy/2 = 5ms = 5000 loops
581                          */
582                         unsigned long k = dev->recon_tmo;
583                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
584                              k--)
585                                 udelay(1);
586
587                         if (!k)
588                                 return 0;
589                 }
590
591                 /* determine if we should use burst I/O */
592                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
593                     ? PPA_BURST_SIZE : 1;
594
595                 if (r == (unsigned char) 0xc0)
596                         status = ppa_out(dev, cmd->SCp.ptr, fast);
597                 else
598                         status = ppa_in(dev, cmd->SCp.ptr, fast);
599
600                 cmd->SCp.ptr += fast;
601                 cmd->SCp.this_residual -= fast;
602
603                 if (!status) {
604                         ppa_fail(dev, DID_BUS_BUSY);
605                         return -1;      /* ERROR_RETURN */
606                 }
607                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
608                         /* if scatter/gather, advance to the next segment */
609                         if (cmd->SCp.buffers_residual--) {
610                                 cmd->SCp.buffer++;
611                                 cmd->SCp.this_residual =
612                                     cmd->SCp.buffer->length;
613                                 cmd->SCp.ptr =
614                                     page_address(cmd->SCp.buffer->page) +
615                                     cmd->SCp.buffer->offset;
616                         }
617                 }
618                 /* Now check to see if the drive is ready to comunicate */
619                 r = (r_str(ppb) & 0xf0);
620                 /* If not, drop back down to the scheduler and wait a timer tick */
621                 if (!(r & 0x80))
622                         return 0;
623         }
624         return 1;               /* FINISH_RETURN */
625 }
626
627 /*
628  * Since the PPA itself doesn't generate interrupts, we use
629  * the scheduler's task queue to generate a stream of call-backs and
630  * complete the request when the drive is ready.
631  */
632 static void ppa_interrupt(void *data)
633 {
634         ppa_struct *dev = (ppa_struct *) data;
635         struct scsi_cmnd *cmd = dev->cur_cmd;
636
637         if (!cmd) {
638                 printk("PPA: bug in ppa_interrupt\n");
639                 return;
640         }
641         if (ppa_engine(dev, cmd)) {
642                 dev->ppa_tq.data = (void *) dev;
643                 schedule_delayed_work(&dev->ppa_tq, 1);
644                 return;
645         }
646         /* Command must of completed hence it is safe to let go... */
647 #if PPA_DEBUG > 0
648         switch ((cmd->result >> 16) & 0xff) {
649         case DID_OK:
650                 break;
651         case DID_NO_CONNECT:
652                 printk("ppa: no device at SCSI ID %i\n", cmd->device->target);
653                 break;
654         case DID_BUS_BUSY:
655                 printk("ppa: BUS BUSY - EPP timeout detected\n");
656                 break;
657         case DID_TIME_OUT:
658                 printk("ppa: unknown timeout\n");
659                 break;
660         case DID_ABORT:
661                 printk("ppa: told to abort\n");
662                 break;
663         case DID_PARITY:
664                 printk("ppa: parity error (???)\n");
665                 break;
666         case DID_ERROR:
667                 printk("ppa: internal driver error\n");
668                 break;
669         case DID_RESET:
670                 printk("ppa: told to reset device\n");
671                 break;
672         case DID_BAD_INTR:
673                 printk("ppa: bad interrupt (???)\n");
674                 break;
675         default:
676                 printk("ppa: bad return code (%02x)\n",
677                        (cmd->result >> 16) & 0xff);
678         }
679 #endif
680
681         if (cmd->SCp.phase > 1)
682                 ppa_disconnect(dev);
683
684         ppa_pb_dismiss(dev);
685
686         dev->cur_cmd = NULL;
687
688         cmd->scsi_done(cmd);
689 }
690
691 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
692 {
693         unsigned short ppb = dev->base;
694         unsigned char l = 0, h = 0;
695         int retv;
696
697         /* First check for any errors that may of occurred
698          * Here we check for internal errors
699          */
700         if (dev->failed)
701                 return 0;
702
703         switch (cmd->SCp.phase) {
704         case 0:         /* Phase 0 - Waiting for parport */
705                 if (time_after(jiffies, dev->jstart + HZ)) {
706                         /*
707                          * We waited more than a second
708                          * for parport to call us
709                          */
710                         ppa_fail(dev, DID_BUS_BUSY);
711                         return 0;
712                 }
713                 return 1;       /* wait until ppa_wakeup claims parport */
714         case 1:         /* Phase 1 - Connected */
715                 {               /* Perform a sanity check for cable unplugged */
716                         int retv = 2;   /* Failed */
717
718                         ppa_connect(dev, CONNECT_EPP_MAYBE);
719
720                         w_ctr(ppb, 0xe);
721                         if ((r_str(ppb) & 0x08) == 0x08)
722                                 retv--;
723
724                         w_ctr(ppb, 0xc);
725                         if ((r_str(ppb) & 0x08) == 0x00)
726                                 retv--;
727
728                         if (retv) {
729                                 if ((jiffies - dev->jstart) > (1 * HZ)) {
730                                         printk
731                                             ("ppa: Parallel port cable is unplugged!!\n");
732                                         ppa_fail(dev, DID_BUS_BUSY);
733                                         return 0;
734                                 } else {
735                                         ppa_disconnect(dev);
736                                         return 1;       /* Try again in a jiffy */
737                                 }
738                         }
739                         cmd->SCp.phase++;
740                 }
741
742         case 2:         /* Phase 2 - We are now talking to the scsi bus */
743                 if (!ppa_select(dev, scmd_id(cmd))) {
744                         ppa_fail(dev, DID_NO_CONNECT);
745                         return 0;
746                 }
747                 cmd->SCp.phase++;
748
749         case 3:         /* Phase 3 - Ready to accept a command */
750                 w_ctr(ppb, 0x0c);
751                 if (!(r_str(ppb) & 0x80))
752                         return 1;
753
754                 if (!ppa_send_command(cmd))
755                         return 0;
756                 cmd->SCp.phase++;
757
758         case 4:         /* Phase 4 - Setup scatter/gather buffers */
759                 if (cmd->use_sg) {
760                         /* if many buffers are available, start filling the first */
761                         cmd->SCp.buffer =
762                             (struct scatterlist *) cmd->request_buffer;
763                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
764                         cmd->SCp.ptr =
765                             page_address(cmd->SCp.buffer->page) +
766                             cmd->SCp.buffer->offset;
767                 } else {
768                         /* else fill the only available buffer */
769                         cmd->SCp.buffer = NULL;
770                         cmd->SCp.this_residual = cmd->request_bufflen;
771                         cmd->SCp.ptr = cmd->request_buffer;
772                 }
773                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
774                 cmd->SCp.phase++;
775
776         case 5:         /* Phase 5 - Data transfer stage */
777                 w_ctr(ppb, 0x0c);
778                 if (!(r_str(ppb) & 0x80))
779                         return 1;
780
781                 retv = ppa_completion(cmd);
782                 if (retv == -1)
783                         return 0;
784                 if (retv == 0)
785                         return 1;
786                 cmd->SCp.phase++;
787
788         case 6:         /* Phase 6 - Read status/message */
789                 cmd->result = DID_OK << 16;
790                 /* Check for data overrun */
791                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
792                         ppa_fail(dev, DID_ERROR);
793                         return 0;
794                 }
795                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
796                         /* Check for optional message byte */
797                         if (ppa_wait(dev) == (unsigned char) 0xf0)
798                                 ppa_in(dev, &h, 1);
799                         cmd->result =
800                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
801                 }
802                 return 0;       /* Finished */
803                 break;
804
805         default:
806                 printk("ppa: Invalid scsi phase\n");
807         }
808         return 0;
809 }
810
811 static int ppa_queuecommand(struct scsi_cmnd *cmd,
812                 void (*done) (struct scsi_cmnd *))
813 {
814         ppa_struct *dev = ppa_dev(cmd->device->host);
815
816         if (dev->cur_cmd) {
817                 printk("PPA: bug in ppa_queuecommand\n");
818                 return 0;
819         }
820         dev->failed = 0;
821         dev->jstart = jiffies;
822         dev->cur_cmd = cmd;
823         cmd->scsi_done = done;
824         cmd->result = DID_ERROR << 16;  /* default return code */
825         cmd->SCp.phase = 0;     /* bus free */
826
827         dev->ppa_tq.data = dev;
828         schedule_work(&dev->ppa_tq);
829
830         ppa_pb_claim(dev);
831
832         return 0;
833 }
834
835 /*
836  * Apparently the disk->capacity attribute is off by 1 sector 
837  * for all disk drives.  We add the one here, but it should really
838  * be done in sd.c.  Even if it gets fixed there, this will still
839  * work.
840  */
841 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
842               sector_t capacity, int ip[])
843 {
844         ip[0] = 0x40;
845         ip[1] = 0x20;
846         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
847         if (ip[2] > 1024) {
848                 ip[0] = 0xff;
849                 ip[1] = 0x3f;
850                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
851                 if (ip[2] > 1023)
852                         ip[2] = 1023;
853         }
854         return 0;
855 }
856
857 static int ppa_abort(struct scsi_cmnd *cmd)
858 {
859         ppa_struct *dev = ppa_dev(cmd->device->host);
860         /*
861          * There is no method for aborting commands since Iomega
862          * have tied the SCSI_MESSAGE line high in the interface
863          */
864
865         switch (cmd->SCp.phase) {
866         case 0:         /* Do not have access to parport */
867         case 1:         /* Have not connected to interface */
868                 dev->cur_cmd = NULL;    /* Forget the problem */
869                 return SUCCESS;
870                 break;
871         default:                /* SCSI command sent, can not abort */
872                 return FAILED;
873                 break;
874         }
875 }
876
877 static void ppa_reset_pulse(unsigned int base)
878 {
879         w_dtr(base, 0x40);
880         w_ctr(base, 0x8);
881         udelay(30);
882         w_ctr(base, 0xc);
883 }
884
885 static int ppa_reset(struct scsi_cmnd *cmd)
886 {
887         ppa_struct *dev = ppa_dev(cmd->device->host);
888
889         if (cmd->SCp.phase)
890                 ppa_disconnect(dev);
891         dev->cur_cmd = NULL;    /* Forget the problem */
892
893         ppa_connect(dev, CONNECT_NORMAL);
894         ppa_reset_pulse(dev->base);
895         mdelay(1);              /* device settle delay */
896         ppa_disconnect(dev);
897         mdelay(1);              /* device settle delay */
898         return SUCCESS;
899 }
900
901 static int device_check(ppa_struct *dev)
902 {
903         /* This routine looks for a device and then attempts to use EPP
904            to send a command. If all goes as planned then EPP is available. */
905
906         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
907         int loop, old_mode, status, k, ppb = dev->base;
908         unsigned char l;
909
910         old_mode = dev->mode;
911         for (loop = 0; loop < 8; loop++) {
912                 /* Attempt to use EPP for Test Unit Ready */
913                 if ((ppb & 0x0007) == 0x0000)
914                         dev->mode = PPA_EPP_32;
915
916               second_pass:
917                 ppa_connect(dev, CONNECT_EPP_MAYBE);
918                 /* Select SCSI device */
919                 if (!ppa_select(dev, loop)) {
920                         ppa_disconnect(dev);
921                         continue;
922                 }
923                 printk("ppa: Found device at ID %i, Attempting to use %s\n",
924                        loop, PPA_MODE_STRING[dev->mode]);
925
926                 /* Send SCSI command */
927                 status = 1;
928                 w_ctr(ppb, 0x0c);
929                 for (l = 0; (l < 6) && (status); l++)
930                         status = ppa_out(dev, cmd, 1);
931
932                 if (!status) {
933                         ppa_disconnect(dev);
934                         ppa_connect(dev, CONNECT_EPP_MAYBE);
935                         w_dtr(ppb, 0x40);
936                         w_ctr(ppb, 0x08);
937                         udelay(30);
938                         w_ctr(ppb, 0x0c);
939                         udelay(1000);
940                         ppa_disconnect(dev);
941                         udelay(1000);
942                         if (dev->mode == PPA_EPP_32) {
943                                 dev->mode = old_mode;
944                                 goto second_pass;
945                         }
946                         return -EIO;
947                 }
948                 w_ctr(ppb, 0x0c);
949                 k = 1000000;    /* 1 Second */
950                 do {
951                         l = r_str(ppb);
952                         k--;
953                         udelay(1);
954                 } while (!(l & 0x80) && (k));
955
956                 l &= 0xf0;
957
958                 if (l != 0xf0) {
959                         ppa_disconnect(dev);
960                         ppa_connect(dev, CONNECT_EPP_MAYBE);
961                         ppa_reset_pulse(ppb);
962                         udelay(1000);
963                         ppa_disconnect(dev);
964                         udelay(1000);
965                         if (dev->mode == PPA_EPP_32) {
966                                 dev->mode = old_mode;
967                                 goto second_pass;
968                         }
969                         return -EIO;
970                 }
971                 ppa_disconnect(dev);
972                 printk("ppa: Communication established with ID %i using %s\n",
973                        loop, PPA_MODE_STRING[dev->mode]);
974                 ppa_connect(dev, CONNECT_EPP_MAYBE);
975                 ppa_reset_pulse(ppb);
976                 udelay(1000);
977                 ppa_disconnect(dev);
978                 udelay(1000);
979                 return 0;
980         }
981         return -ENODEV;
982 }
983
984 static struct scsi_host_template ppa_template = {
985         .module                 = THIS_MODULE,
986         .proc_name              = "ppa",
987         .proc_info              = ppa_proc_info,
988         .name                   = "Iomega VPI0 (ppa) interface",
989         .queuecommand           = ppa_queuecommand,
990         .eh_abort_handler       = ppa_abort,
991         .eh_bus_reset_handler   = ppa_reset,
992         .eh_host_reset_handler  = ppa_reset,
993         .bios_param             = ppa_biosparam,
994         .this_id                = -1,
995         .sg_tablesize           = SG_ALL,
996         .cmd_per_lun            = 1,
997         .use_clustering         = ENABLE_CLUSTERING,
998         .can_queue              = 1,
999 };
1000
1001 /***************************************************************************
1002  *                   Parallel port probing routines                        *
1003  ***************************************************************************/
1004
1005 static LIST_HEAD(ppa_hosts);
1006
1007 static int __ppa_attach(struct parport *pb)
1008 {
1009         struct Scsi_Host *host;
1010         DECLARE_WAIT_QUEUE_HEAD(waiting);
1011         DEFINE_WAIT(wait);
1012         ppa_struct *dev;
1013         int ports;
1014         int modes, ppb, ppb_hi;
1015         int err = -ENOMEM;
1016
1017         dev = kmalloc(sizeof(ppa_struct), GFP_KERNEL);
1018         if (!dev)
1019                 return -ENOMEM;
1020         memset(dev, 0, sizeof(ppa_struct));
1021         dev->base = -1;
1022         dev->mode = PPA_AUTODETECT;
1023         dev->recon_tmo = PPA_RECON_TMO;
1024         init_waitqueue_head(&waiting);
1025         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1026                                             NULL, 0, dev);
1027
1028         if (!dev->dev)
1029                 goto out;
1030
1031         /* Claim the bus so it remembers what we do to the control
1032          * registers. [ CTR and ECP ]
1033          */
1034         err = -EBUSY;
1035         dev->waiting = &waiting;
1036         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1037         if (ppa_pb_claim(dev))
1038                 schedule_timeout(3 * HZ);
1039         if (dev->wanted) {
1040                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1041                                 "a pardevice is owning the port for too long "
1042                                 "time!\n", pb->number);
1043                 ppa_pb_dismiss(dev);
1044                 dev->waiting = NULL;
1045                 finish_wait(&waiting, &wait);
1046                 goto out1;
1047         }
1048         dev->waiting = NULL;
1049         finish_wait(&waiting, &wait);
1050         ppb = dev->base = dev->dev->port->base;
1051         ppb_hi = dev->dev->port->base_hi;
1052         w_ctr(ppb, 0x0c);
1053         modes = dev->dev->port->modes;
1054
1055         /* Mode detection works up the chain of speed
1056          * This avoids a nasty if-then-else-if-... tree
1057          */
1058         dev->mode = PPA_NIBBLE;
1059
1060         if (modes & PARPORT_MODE_TRISTATE)
1061                 dev->mode = PPA_PS2;
1062
1063         if (modes & PARPORT_MODE_ECP) {
1064                 w_ecr(ppb_hi, 0x20);
1065                 dev->mode = PPA_PS2;
1066         }
1067         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1068                 w_ecr(ppb_hi, 0x80);
1069
1070         /* Done configuration */
1071
1072         err = ppa_init(dev);
1073         ppa_pb_release(dev);
1074
1075         if (err)
1076                 goto out1;
1077
1078         /* now the glue ... */
1079         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1080                 ports = 3;
1081         else
1082                 ports = 8;
1083
1084         INIT_WORK(&dev->ppa_tq, ppa_interrupt, dev);
1085
1086         err = -ENOMEM;
1087         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1088         if (!host)
1089                 goto out1;
1090         host->io_port = pb->base;
1091         host->n_io_port = ports;
1092         host->dma_channel = -1;
1093         host->unique_id = pb->number;
1094         *(ppa_struct **)&host->hostdata = dev;
1095         dev->host = host;
1096         list_add_tail(&dev->list, &ppa_hosts);
1097         err = scsi_add_host(host, NULL);
1098         if (err)
1099                 goto out2;
1100         scsi_scan_host(host);
1101         return 0;
1102 out2:
1103         list_del_init(&dev->list);
1104         scsi_host_put(host);
1105 out1:
1106         parport_unregister_device(dev->dev);
1107 out:
1108         kfree(dev);
1109         return err;
1110 }
1111
1112 static void ppa_attach(struct parport *pb)
1113 {
1114         __ppa_attach(pb);
1115 }
1116
1117 static void ppa_detach(struct parport *pb)
1118 {
1119         ppa_struct *dev;
1120         list_for_each_entry(dev, &ppa_hosts, list) {
1121                 if (dev->dev->port == pb) {
1122                         list_del_init(&dev->list);
1123                         scsi_remove_host(dev->host);
1124                         scsi_host_put(dev->host);
1125                         parport_unregister_device(dev->dev);
1126                         kfree(dev);
1127                         break;
1128                 }
1129         }
1130 }
1131
1132 static struct parport_driver ppa_driver = {
1133         .name   = "ppa",
1134         .attach = ppa_attach,
1135         .detach = ppa_detach,
1136 };
1137
1138 static int __init ppa_driver_init(void)
1139 {
1140         printk("ppa: Version %s\n", PPA_VERSION);
1141         return parport_register_driver(&ppa_driver);
1142 }
1143
1144 static void __exit ppa_driver_exit(void)
1145 {
1146         parport_unregister_driver(&ppa_driver);
1147 }
1148
1149 module_init(ppa_driver_init);
1150 module_exit(ppa_driver_exit);
1151 MODULE_LICENSE("GPL");