Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
[firefly-linux-kernel-4.4.55.git] / 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  */
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    */
40         wait_queue_head_t *waiting;
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_write_info(struct Scsi_Host *host, char *buffer, int length)
122 {
123         ppa_struct *dev = ppa_dev(host);
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(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
135                 return length;
136         }
137         printk(KERN_WARNING "ppa /proc: invalid variable\n");
138         return -EINVAL;
139 }
140
141 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
142 {
143         ppa_struct *dev = ppa_dev(host);
144
145         seq_printf(m, "Version : %s\n", PPA_VERSION);
146         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
147         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
148 #if PPA_DEBUG > 0
149         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
150 #endif
151         return 0;
152 }
153
154 static int device_check(ppa_struct *dev);
155
156 #if PPA_DEBUG > 0
157 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
158            y, __func__, __LINE__); ppa_fail_func(x,y);
159 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
160 #else
161 static inline void ppa_fail(ppa_struct *dev, int error_code)
162 #endif
163 {
164         /* If we fail a device then we trash status / message bytes */
165         if (dev->cur_cmd) {
166                 dev->cur_cmd->result = error_code << 16;
167                 dev->failed = 1;
168         }
169 }
170
171 /*
172  * Wait for the high bit to be set.
173  * 
174  * In principle, this could be tied to an interrupt, but the adapter
175  * doesn't appear to be designed to support interrupts.  We spin on
176  * the 0x80 ready bit. 
177  */
178 static unsigned char ppa_wait(ppa_struct *dev)
179 {
180         int k;
181         unsigned short ppb = dev->base;
182         unsigned char r;
183
184         k = PPA_SPIN_TMO;
185         /* Wait for bit 6 and 7 - PJC */
186         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
187                 udelay(1);
188                 r = r_str(ppb);
189         }
190
191         /*
192          * return some status information.
193          * Semantics: 0xc0 = ZIP wants more data
194          *            0xd0 = ZIP wants to send more data
195          *            0xe0 = ZIP is expecting SCSI command data
196          *            0xf0 = end of transfer, ZIP is sending status
197          */
198         if (k)
199                 return (r & 0xf0);
200
201         /* Counter expired - Time out occurred */
202         ppa_fail(dev, DID_TIME_OUT);
203         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
204         return 0;               /* command timed out */
205 }
206
207 /*
208  * Clear EPP Timeout Bit 
209  */
210 static inline void epp_reset(unsigned short ppb)
211 {
212         int i;
213
214         i = r_str(ppb);
215         w_str(ppb, i);
216         w_str(ppb, i & 0xfe);
217 }
218
219 /* 
220  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
221  */
222 static inline void ecp_sync(ppa_struct *dev)
223 {
224         int i, ppb_hi = dev->dev->port->base_hi;
225
226         if (ppb_hi == 0)
227                 return;
228
229         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
230                 for (i = 0; i < 100; i++) {
231                         if (r_ecr(ppb_hi) & 0x01)
232                                 return;
233                         udelay(5);
234                 }
235                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
236         }
237 }
238
239 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
240 {
241         int i;
242
243         for (i = len; i; i--) {
244                 w_dtr(base, *buffer++);
245                 w_ctr(base, 0xe);
246                 w_ctr(base, 0xc);
247         }
248         return 1;               /* All went well - we hope! */
249 }
250
251 static int ppa_byte_in(unsigned short base, char *buffer, int len)
252 {
253         int i;
254
255         for (i = len; i; i--) {
256                 *buffer++ = r_dtr(base);
257                 w_ctr(base, 0x27);
258                 w_ctr(base, 0x25);
259         }
260         return 1;               /* All went well - we hope! */
261 }
262
263 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
264 {
265         for (; len; len--) {
266                 unsigned char h;
267
268                 w_ctr(base, 0x4);
269                 h = r_str(base) & 0xf0;
270                 w_ctr(base, 0x6);
271                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
272         }
273         return 1;               /* All went well - we hope! */
274 }
275
276 static int ppa_out(ppa_struct *dev, char *buffer, int len)
277 {
278         int r;
279         unsigned short ppb = dev->base;
280
281         r = ppa_wait(dev);
282
283         if ((r & 0x50) != 0x40) {
284                 ppa_fail(dev, DID_ERROR);
285                 return 0;
286         }
287         switch (dev->mode) {
288         case PPA_NIBBLE:
289         case PPA_PS2:
290                 /* 8 bit output, with a loop */
291                 r = ppa_byte_out(ppb, buffer, len);
292                 break;
293
294         case PPA_EPP_32:
295         case PPA_EPP_16:
296         case PPA_EPP_8:
297                 epp_reset(ppb);
298                 w_ctr(ppb, 0x4);
299 #ifdef CONFIG_SCSI_IZIP_EPP16
300                 if (!(((long) buffer | len) & 0x01))
301                         outsw(ppb + 4, buffer, len >> 1);
302 #else
303                 if (!(((long) buffer | len) & 0x03))
304                         outsl(ppb + 4, buffer, len >> 2);
305 #endif
306                 else
307                         outsb(ppb + 4, buffer, len);
308                 w_ctr(ppb, 0xc);
309                 r = !(r_str(ppb) & 0x01);
310                 w_ctr(ppb, 0xc);
311                 ecp_sync(dev);
312                 break;
313
314         default:
315                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
316                 r = 0;
317         }
318         return r;
319 }
320
321 static int ppa_in(ppa_struct *dev, char *buffer, int len)
322 {
323         int r;
324         unsigned short ppb = dev->base;
325
326         r = ppa_wait(dev);
327
328         if ((r & 0x50) != 0x50) {
329                 ppa_fail(dev, DID_ERROR);
330                 return 0;
331         }
332         switch (dev->mode) {
333         case PPA_NIBBLE:
334                 /* 4 bit input, with a loop */
335                 r = ppa_nibble_in(ppb, buffer, len);
336                 w_ctr(ppb, 0xc);
337                 break;
338
339         case PPA_PS2:
340                 /* 8 bit input, with a loop */
341                 w_ctr(ppb, 0x25);
342                 r = ppa_byte_in(ppb, buffer, len);
343                 w_ctr(ppb, 0x4);
344                 w_ctr(ppb, 0xc);
345                 break;
346
347         case PPA_EPP_32:
348         case PPA_EPP_16:
349         case PPA_EPP_8:
350                 epp_reset(ppb);
351                 w_ctr(ppb, 0x24);
352 #ifdef CONFIG_SCSI_IZIP_EPP16
353                 if (!(((long) buffer | len) & 0x01))
354                         insw(ppb + 4, buffer, len >> 1);
355 #else
356                 if (!(((long) buffer | len) & 0x03))
357                         insl(ppb + 4, buffer, len >> 2);
358 #endif
359                 else
360                         insb(ppb + 4, buffer, len);
361                 w_ctr(ppb, 0x2c);
362                 r = !(r_str(ppb) & 0x01);
363                 w_ctr(ppb, 0x2c);
364                 ecp_sync(dev);
365                 break;
366
367         default:
368                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
369                 r = 0;
370                 break;
371         }
372         return r;
373 }
374
375 /* end of ppa_io.h */
376 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
377 {
378         w_dtr(ppb, b);
379         w_ctr(ppb, 0xc);
380         w_ctr(ppb, 0xe);
381         w_ctr(ppb, 0xc);
382         w_ctr(ppb, 0x4);
383         w_ctr(ppb, 0xc);
384 }
385
386 static void ppa_disconnect(ppa_struct *dev)
387 {
388         unsigned short ppb = dev->base;
389
390         ppa_d_pulse(ppb, 0);
391         ppa_d_pulse(ppb, 0x3c);
392         ppa_d_pulse(ppb, 0x20);
393         ppa_d_pulse(ppb, 0xf);
394 }
395
396 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
397 {
398         w_dtr(ppb, b);
399         w_ctr(ppb, 0x4);
400         w_ctr(ppb, 0x6);
401         w_ctr(ppb, 0x4);
402         w_ctr(ppb, 0xc);
403 }
404
405 static inline void ppa_connect(ppa_struct *dev, int flag)
406 {
407         unsigned short ppb = dev->base;
408
409         ppa_c_pulse(ppb, 0);
410         ppa_c_pulse(ppb, 0x3c);
411         ppa_c_pulse(ppb, 0x20);
412         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
413                 ppa_c_pulse(ppb, 0xcf);
414         else
415                 ppa_c_pulse(ppb, 0x8f);
416 }
417
418 static int ppa_select(ppa_struct *dev, int target)
419 {
420         int k;
421         unsigned short ppb = dev->base;
422
423         /*
424          * Bit 6 (0x40) is the device selected bit.
425          * First we must wait till the current device goes off line...
426          */
427         k = PPA_SELECT_TMO;
428         do {
429                 k--;
430                 udelay(1);
431         } while ((r_str(ppb) & 0x40) && (k));
432         if (!k)
433                 return 0;
434
435         w_dtr(ppb, (1 << target));
436         w_ctr(ppb, 0xe);
437         w_ctr(ppb, 0xc);
438         w_dtr(ppb, 0x80);       /* This is NOT the initator */
439         w_ctr(ppb, 0x8);
440
441         k = PPA_SELECT_TMO;
442         do {
443                 k--;
444                 udelay(1);
445         }
446         while (!(r_str(ppb) & 0x40) && (k));
447         if (!k)
448                 return 0;
449
450         return 1;
451 }
452
453 /* 
454  * This is based on a trace of what the Iomega DOS 'guest' driver does.
455  * I've tried several different kinds of parallel ports with guest and
456  * coded this to react in the same ways that it does.
457  * 
458  * The return value from this function is just a hint about where the
459  * handshaking failed.
460  * 
461  */
462 static int ppa_init(ppa_struct *dev)
463 {
464         int retv;
465         unsigned short ppb = dev->base;
466
467         ppa_disconnect(dev);
468         ppa_connect(dev, CONNECT_NORMAL);
469
470         retv = 2;               /* Failed */
471
472         w_ctr(ppb, 0xe);
473         if ((r_str(ppb) & 0x08) == 0x08)
474                 retv--;
475
476         w_ctr(ppb, 0xc);
477         if ((r_str(ppb) & 0x08) == 0x00)
478                 retv--;
479
480         if (!retv)
481                 ppa_reset_pulse(ppb);
482         udelay(1000);           /* Allow devices to settle down */
483         ppa_disconnect(dev);
484         udelay(1000);           /* Another delay to allow devices to settle */
485
486         if (retv)
487                 return -EIO;
488
489         return device_check(dev);
490 }
491
492 static inline int ppa_send_command(struct scsi_cmnd *cmd)
493 {
494         ppa_struct *dev = ppa_dev(cmd->device->host);
495         int k;
496
497         w_ctr(dev->base, 0x0c);
498
499         for (k = 0; k < cmd->cmd_len; k++)
500                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
501                         return 0;
502         return 1;
503 }
504
505 /*
506  * The bulk flag enables some optimisations in the data transfer loops,
507  * it should be true for any command that transfers data in integral
508  * numbers of sectors.
509  * 
510  * The driver appears to remain stable if we speed up the parallel port
511  * i/o in this function, but not elsewhere.
512  */
513 static int ppa_completion(struct scsi_cmnd *cmd)
514 {
515         /* Return codes:
516          * -1     Error
517          *  0     Told to schedule
518          *  1     Finished data transfer
519          */
520         ppa_struct *dev = ppa_dev(cmd->device->host);
521         unsigned short ppb = dev->base;
522         unsigned long start_jiffies = jiffies;
523
524         unsigned char r, v;
525         int fast, bulk, status;
526
527         v = cmd->cmnd[0];
528         bulk = ((v == READ_6) ||
529                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
530
531         /*
532          * We only get here if the drive is ready to comunicate,
533          * hence no need for a full ppa_wait.
534          */
535         r = (r_str(ppb) & 0xf0);
536
537         while (r != (unsigned char) 0xf0) {
538                 /*
539                  * If we have been running for more than a full timer tick
540                  * then take a rest.
541                  */
542                 if (time_after(jiffies, start_jiffies + 1))
543                         return 0;
544
545                 if ((cmd->SCp.this_residual <= 0)) {
546                         ppa_fail(dev, DID_ERROR);
547                         return -1;      /* ERROR_RETURN */
548                 }
549
550                 /* On some hardware we have SCSI disconnected (6th bit low)
551                  * for about 100usecs. It is too expensive to wait a 
552                  * tick on every loop so we busy wait for no more than
553                  * 500usecs to give the drive a chance first. We do not 
554                  * change things for "normal" hardware since generally 
555                  * the 6th bit is always high.
556                  * This makes the CPU load higher on some hardware 
557                  * but otherwise we can not get more than 50K/secs 
558                  * on this problem hardware.
559                  */
560                 if ((r & 0xc0) != 0xc0) {
561                         /* Wait for reconnection should be no more than 
562                          * jiffy/2 = 5ms = 5000 loops
563                          */
564                         unsigned long k = dev->recon_tmo;
565                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
566                              k--)
567                                 udelay(1);
568
569                         if (!k)
570                                 return 0;
571                 }
572
573                 /* determine if we should use burst I/O */
574                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
575                     ? PPA_BURST_SIZE : 1;
576
577                 if (r == (unsigned char) 0xc0)
578                         status = ppa_out(dev, cmd->SCp.ptr, fast);
579                 else
580                         status = ppa_in(dev, cmd->SCp.ptr, fast);
581
582                 cmd->SCp.ptr += fast;
583                 cmd->SCp.this_residual -= fast;
584
585                 if (!status) {
586                         ppa_fail(dev, DID_BUS_BUSY);
587                         return -1;      /* ERROR_RETURN */
588                 }
589                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
590                         /* if scatter/gather, advance to the next segment */
591                         if (cmd->SCp.buffers_residual--) {
592                                 cmd->SCp.buffer++;
593                                 cmd->SCp.this_residual =
594                                     cmd->SCp.buffer->length;
595                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
596                         }
597                 }
598                 /* Now check to see if the drive is ready to comunicate */
599                 r = (r_str(ppb) & 0xf0);
600                 /* If not, drop back down to the scheduler and wait a timer tick */
601                 if (!(r & 0x80))
602                         return 0;
603         }
604         return 1;               /* FINISH_RETURN */
605 }
606
607 /*
608  * Since the PPA itself doesn't generate interrupts, we use
609  * the scheduler's task queue to generate a stream of call-backs and
610  * complete the request when the drive is ready.
611  */
612 static void ppa_interrupt(struct work_struct *work)
613 {
614         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
615         struct scsi_cmnd *cmd = dev->cur_cmd;
616
617         if (!cmd) {
618                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
619                 return;
620         }
621         if (ppa_engine(dev, cmd)) {
622                 schedule_delayed_work(&dev->ppa_tq, 1);
623                 return;
624         }
625         /* Command must of completed hence it is safe to let go... */
626 #if PPA_DEBUG > 0
627         switch ((cmd->result >> 16) & 0xff) {
628         case DID_OK:
629                 break;
630         case DID_NO_CONNECT:
631                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
632                 break;
633         case DID_BUS_BUSY:
634                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
635                 break;
636         case DID_TIME_OUT:
637                 printk(KERN_DEBUG "ppa: unknown timeout\n");
638                 break;
639         case DID_ABORT:
640                 printk(KERN_DEBUG "ppa: told to abort\n");
641                 break;
642         case DID_PARITY:
643                 printk(KERN_DEBUG "ppa: parity error (???)\n");
644                 break;
645         case DID_ERROR:
646                 printk(KERN_DEBUG "ppa: internal driver error\n");
647                 break;
648         case DID_RESET:
649                 printk(KERN_DEBUG "ppa: told to reset device\n");
650                 break;
651         case DID_BAD_INTR:
652                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
653                 break;
654         default:
655                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
656                        (cmd->result >> 16) & 0xff);
657         }
658 #endif
659
660         if (cmd->SCp.phase > 1)
661                 ppa_disconnect(dev);
662
663         ppa_pb_dismiss(dev);
664
665         dev->cur_cmd = NULL;
666
667         cmd->scsi_done(cmd);
668 }
669
670 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
671 {
672         unsigned short ppb = dev->base;
673         unsigned char l = 0, h = 0;
674         int retv;
675
676         /* First check for any errors that may of occurred
677          * Here we check for internal errors
678          */
679         if (dev->failed)
680                 return 0;
681
682         switch (cmd->SCp.phase) {
683         case 0:         /* Phase 0 - Waiting for parport */
684                 if (time_after(jiffies, dev->jstart + HZ)) {
685                         /*
686                          * We waited more than a second
687                          * for parport to call us
688                          */
689                         ppa_fail(dev, DID_BUS_BUSY);
690                         return 0;
691                 }
692                 return 1;       /* wait until ppa_wakeup claims parport */
693         case 1:         /* Phase 1 - Connected */
694                 {               /* Perform a sanity check for cable unplugged */
695                         int retv = 2;   /* Failed */
696
697                         ppa_connect(dev, CONNECT_EPP_MAYBE);
698
699                         w_ctr(ppb, 0xe);
700                         if ((r_str(ppb) & 0x08) == 0x08)
701                                 retv--;
702
703                         w_ctr(ppb, 0xc);
704                         if ((r_str(ppb) & 0x08) == 0x00)
705                                 retv--;
706
707                         if (retv) {
708                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
709                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
710                                         ppa_fail(dev, DID_BUS_BUSY);
711                                         return 0;
712                                 } else {
713                                         ppa_disconnect(dev);
714                                         return 1;       /* Try again in a jiffy */
715                                 }
716                         }
717                         cmd->SCp.phase++;
718                 }
719
720         case 2:         /* Phase 2 - We are now talking to the scsi bus */
721                 if (!ppa_select(dev, scmd_id(cmd))) {
722                         ppa_fail(dev, DID_NO_CONNECT);
723                         return 0;
724                 }
725                 cmd->SCp.phase++;
726
727         case 3:         /* Phase 3 - Ready to accept a command */
728                 w_ctr(ppb, 0x0c);
729                 if (!(r_str(ppb) & 0x80))
730                         return 1;
731
732                 if (!ppa_send_command(cmd))
733                         return 0;
734                 cmd->SCp.phase++;
735
736         case 4:         /* Phase 4 - Setup scatter/gather buffers */
737                 if (scsi_bufflen(cmd)) {
738                         cmd->SCp.buffer = scsi_sglist(cmd);
739                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
740                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
741                 } else {
742                         cmd->SCp.buffer = NULL;
743                         cmd->SCp.this_residual = 0;
744                         cmd->SCp.ptr = NULL;
745                 }
746                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
747                 cmd->SCp.phase++;
748
749         case 5:         /* Phase 5 - Data transfer stage */
750                 w_ctr(ppb, 0x0c);
751                 if (!(r_str(ppb) & 0x80))
752                         return 1;
753
754                 retv = ppa_completion(cmd);
755                 if (retv == -1)
756                         return 0;
757                 if (retv == 0)
758                         return 1;
759                 cmd->SCp.phase++;
760
761         case 6:         /* Phase 6 - Read status/message */
762                 cmd->result = DID_OK << 16;
763                 /* Check for data overrun */
764                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
765                         ppa_fail(dev, DID_ERROR);
766                         return 0;
767                 }
768                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
769                         /* Check for optional message byte */
770                         if (ppa_wait(dev) == (unsigned char) 0xf0)
771                                 ppa_in(dev, &h, 1);
772                         cmd->result =
773                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
774                 }
775                 return 0;       /* Finished */
776                 break;
777
778         default:
779                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
780         }
781         return 0;
782 }
783
784 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
785                 void (*done) (struct scsi_cmnd *))
786 {
787         ppa_struct *dev = ppa_dev(cmd->device->host);
788
789         if (dev->cur_cmd) {
790                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
791                 return 0;
792         }
793         dev->failed = 0;
794         dev->jstart = jiffies;
795         dev->cur_cmd = cmd;
796         cmd->scsi_done = done;
797         cmd->result = DID_ERROR << 16;  /* default return code */
798         cmd->SCp.phase = 0;     /* bus free */
799
800         schedule_delayed_work(&dev->ppa_tq, 0);
801
802         ppa_pb_claim(dev);
803
804         return 0;
805 }
806
807 static DEF_SCSI_QCMD(ppa_queuecommand)
808
809 /*
810  * Apparently the disk->capacity attribute is off by 1 sector 
811  * for all disk drives.  We add the one here, but it should really
812  * be done in sd.c.  Even if it gets fixed there, this will still
813  * work.
814  */
815 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
816               sector_t capacity, int ip[])
817 {
818         ip[0] = 0x40;
819         ip[1] = 0x20;
820         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
821         if (ip[2] > 1024) {
822                 ip[0] = 0xff;
823                 ip[1] = 0x3f;
824                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
825                 if (ip[2] > 1023)
826                         ip[2] = 1023;
827         }
828         return 0;
829 }
830
831 static int ppa_abort(struct scsi_cmnd *cmd)
832 {
833         ppa_struct *dev = ppa_dev(cmd->device->host);
834         /*
835          * There is no method for aborting commands since Iomega
836          * have tied the SCSI_MESSAGE line high in the interface
837          */
838
839         switch (cmd->SCp.phase) {
840         case 0:         /* Do not have access to parport */
841         case 1:         /* Have not connected to interface */
842                 dev->cur_cmd = NULL;    /* Forget the problem */
843                 return SUCCESS;
844                 break;
845         default:                /* SCSI command sent, can not abort */
846                 return FAILED;
847                 break;
848         }
849 }
850
851 static void ppa_reset_pulse(unsigned int base)
852 {
853         w_dtr(base, 0x40);
854         w_ctr(base, 0x8);
855         udelay(30);
856         w_ctr(base, 0xc);
857 }
858
859 static int ppa_reset(struct scsi_cmnd *cmd)
860 {
861         ppa_struct *dev = ppa_dev(cmd->device->host);
862
863         if (cmd->SCp.phase)
864                 ppa_disconnect(dev);
865         dev->cur_cmd = NULL;    /* Forget the problem */
866
867         ppa_connect(dev, CONNECT_NORMAL);
868         ppa_reset_pulse(dev->base);
869         mdelay(1);              /* device settle delay */
870         ppa_disconnect(dev);
871         mdelay(1);              /* device settle delay */
872         return SUCCESS;
873 }
874
875 static int device_check(ppa_struct *dev)
876 {
877         /* This routine looks for a device and then attempts to use EPP
878            to send a command. If all goes as planned then EPP is available. */
879
880         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
881         int loop, old_mode, status, k, ppb = dev->base;
882         unsigned char l;
883
884         old_mode = dev->mode;
885         for (loop = 0; loop < 8; loop++) {
886                 /* Attempt to use EPP for Test Unit Ready */
887                 if ((ppb & 0x0007) == 0x0000)
888                         dev->mode = PPA_EPP_32;
889
890 second_pass:
891                 ppa_connect(dev, CONNECT_EPP_MAYBE);
892                 /* Select SCSI device */
893                 if (!ppa_select(dev, loop)) {
894                         ppa_disconnect(dev);
895                         continue;
896                 }
897                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
898                        loop, PPA_MODE_STRING[dev->mode]);
899
900                 /* Send SCSI command */
901                 status = 1;
902                 w_ctr(ppb, 0x0c);
903                 for (l = 0; (l < 6) && (status); l++)
904                         status = ppa_out(dev, cmd, 1);
905
906                 if (!status) {
907                         ppa_disconnect(dev);
908                         ppa_connect(dev, CONNECT_EPP_MAYBE);
909                         w_dtr(ppb, 0x40);
910                         w_ctr(ppb, 0x08);
911                         udelay(30);
912                         w_ctr(ppb, 0x0c);
913                         udelay(1000);
914                         ppa_disconnect(dev);
915                         udelay(1000);
916                         if (dev->mode == PPA_EPP_32) {
917                                 dev->mode = old_mode;
918                                 goto second_pass;
919                         }
920                         return -EIO;
921                 }
922                 w_ctr(ppb, 0x0c);
923                 k = 1000000;    /* 1 Second */
924                 do {
925                         l = r_str(ppb);
926                         k--;
927                         udelay(1);
928                 } while (!(l & 0x80) && (k));
929
930                 l &= 0xf0;
931
932                 if (l != 0xf0) {
933                         ppa_disconnect(dev);
934                         ppa_connect(dev, CONNECT_EPP_MAYBE);
935                         ppa_reset_pulse(ppb);
936                         udelay(1000);
937                         ppa_disconnect(dev);
938                         udelay(1000);
939                         if (dev->mode == PPA_EPP_32) {
940                                 dev->mode = old_mode;
941                                 goto second_pass;
942                         }
943                         return -EIO;
944                 }
945                 ppa_disconnect(dev);
946                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
947                        loop, PPA_MODE_STRING[dev->mode]);
948                 ppa_connect(dev, CONNECT_EPP_MAYBE);
949                 ppa_reset_pulse(ppb);
950                 udelay(1000);
951                 ppa_disconnect(dev);
952                 udelay(1000);
953                 return 0;
954         }
955         return -ENODEV;
956 }
957
958 static int ppa_adjust_queue(struct scsi_device *device)
959 {
960         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
961         return 0;
962 }
963
964 static struct scsi_host_template ppa_template = {
965         .module                 = THIS_MODULE,
966         .proc_name              = "ppa",
967         .show_info              = ppa_show_info,
968         .write_info             = ppa_write_info,
969         .name                   = "Iomega VPI0 (ppa) interface",
970         .queuecommand           = ppa_queuecommand,
971         .eh_abort_handler       = ppa_abort,
972         .eh_bus_reset_handler   = ppa_reset,
973         .eh_host_reset_handler  = ppa_reset,
974         .bios_param             = ppa_biosparam,
975         .this_id                = -1,
976         .sg_tablesize           = SG_ALL,
977         .use_clustering         = ENABLE_CLUSTERING,
978         .can_queue              = 1,
979         .slave_alloc            = ppa_adjust_queue,
980 };
981
982 /***************************************************************************
983  *                   Parallel port probing routines                        *
984  ***************************************************************************/
985
986 static LIST_HEAD(ppa_hosts);
987
988 static int __ppa_attach(struct parport *pb)
989 {
990         struct Scsi_Host *host;
991         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
992         DEFINE_WAIT(wait);
993         ppa_struct *dev;
994         int ports;
995         int modes, ppb, ppb_hi;
996         int err = -ENOMEM;
997
998         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
999         if (!dev)
1000                 return -ENOMEM;
1001         dev->base = -1;
1002         dev->mode = PPA_AUTODETECT;
1003         dev->recon_tmo = PPA_RECON_TMO;
1004         init_waitqueue_head(&waiting);
1005         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1006                                             NULL, 0, dev);
1007
1008         if (!dev->dev)
1009                 goto out;
1010
1011         /* Claim the bus so it remembers what we do to the control
1012          * registers. [ CTR and ECP ]
1013          */
1014         err = -EBUSY;
1015         dev->waiting = &waiting;
1016         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1017         if (ppa_pb_claim(dev))
1018                 schedule_timeout(3 * HZ);
1019         if (dev->wanted) {
1020                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1021                                 "a pardevice is owning the port for too long "
1022                                 "time!\n", pb->number);
1023                 ppa_pb_dismiss(dev);
1024                 dev->waiting = NULL;
1025                 finish_wait(&waiting, &wait);
1026                 goto out1;
1027         }
1028         dev->waiting = NULL;
1029         finish_wait(&waiting, &wait);
1030         ppb = dev->base = dev->dev->port->base;
1031         ppb_hi = dev->dev->port->base_hi;
1032         w_ctr(ppb, 0x0c);
1033         modes = dev->dev->port->modes;
1034
1035         /* Mode detection works up the chain of speed
1036          * This avoids a nasty if-then-else-if-... tree
1037          */
1038         dev->mode = PPA_NIBBLE;
1039
1040         if (modes & PARPORT_MODE_TRISTATE)
1041                 dev->mode = PPA_PS2;
1042
1043         if (modes & PARPORT_MODE_ECP) {
1044                 w_ecr(ppb_hi, 0x20);
1045                 dev->mode = PPA_PS2;
1046         }
1047         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1048                 w_ecr(ppb_hi, 0x80);
1049
1050         /* Done configuration */
1051
1052         err = ppa_init(dev);
1053         ppa_pb_release(dev);
1054
1055         if (err)
1056                 goto out1;
1057
1058         /* now the glue ... */
1059         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1060                 ports = 3;
1061         else
1062                 ports = 8;
1063
1064         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1065
1066         err = -ENOMEM;
1067         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1068         if (!host)
1069                 goto out1;
1070         host->io_port = pb->base;
1071         host->n_io_port = ports;
1072         host->dma_channel = -1;
1073         host->unique_id = pb->number;
1074         *(ppa_struct **)&host->hostdata = dev;
1075         dev->host = host;
1076         list_add_tail(&dev->list, &ppa_hosts);
1077         err = scsi_add_host(host, NULL);
1078         if (err)
1079                 goto out2;
1080         scsi_scan_host(host);
1081         return 0;
1082 out2:
1083         list_del_init(&dev->list);
1084         scsi_host_put(host);
1085 out1:
1086         parport_unregister_device(dev->dev);
1087 out:
1088         kfree(dev);
1089         return err;
1090 }
1091
1092 static void ppa_attach(struct parport *pb)
1093 {
1094         __ppa_attach(pb);
1095 }
1096
1097 static void ppa_detach(struct parport *pb)
1098 {
1099         ppa_struct *dev;
1100         list_for_each_entry(dev, &ppa_hosts, list) {
1101                 if (dev->dev->port == pb) {
1102                         list_del_init(&dev->list);
1103                         scsi_remove_host(dev->host);
1104                         scsi_host_put(dev->host);
1105                         parport_unregister_device(dev->dev);
1106                         kfree(dev);
1107                         break;
1108                 }
1109         }
1110 }
1111
1112 static struct parport_driver ppa_driver = {
1113         .name   = "ppa",
1114         .attach = ppa_attach,
1115         .detach = ppa_detach,
1116 };
1117
1118 static int __init ppa_driver_init(void)
1119 {
1120         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1121         return parport_register_driver(&ppa_driver);
1122 }
1123
1124 static void __exit ppa_driver_exit(void)
1125 {
1126         parport_unregister_driver(&ppa_driver);
1127 }
1128
1129 module_init(ppa_driver_init);
1130 module_exit(ppa_driver_exit);
1131 MODULE_LICENSE("GPL");