WorkStruct: make allyesconfig
[linux-3.10.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/module.h>
14 #include <linux/blkdev.h>
15 #include <linux/parport.h>
16 #include <linux/workqueue.h>
17 #include <linux/delay.h>
18 #include <linux/jiffies.h>
19 #include <asm/io.h>
20
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_cmnd.h>
23 #include <scsi/scsi_device.h>
24 #include <scsi/scsi_host.h>
25
26
27 static void ppa_reset_pulse(unsigned int base);
28
29 typedef struct {
30         struct pardevice *dev;  /* Parport device entry         */
31         int base;               /* Actual port address          */
32         int mode;               /* Transfer mode                */
33         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
34         struct delayed_work ppa_tq;     /* Polling interrupt stuff       */
35         unsigned long jstart;   /* Jiffies at start             */
36         unsigned long recon_tmo;        /* How many usecs to wait for reconnection (6th bit) */
37         unsigned int failed:1;  /* Failure flag                 */
38         unsigned wanted:1;      /* Parport sharing busy flag    */
39         wait_queue_head_t *waiting;
40         struct Scsi_Host *host;
41         struct list_head list;
42 } ppa_struct;
43
44 #include  "ppa.h"
45
46 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
47 {
48         return *(ppa_struct **)&host->hostdata;
49 }
50
51 static DEFINE_SPINLOCK(arbitration_lock);
52
53 static void got_it(ppa_struct *dev)
54 {
55         dev->base = dev->dev->port->base;
56         if (dev->cur_cmd)
57                 dev->cur_cmd->SCp.phase = 1;
58         else
59                 wake_up(dev->waiting);
60 }
61
62 static void ppa_wakeup(void *ref)
63 {
64         ppa_struct *dev = (ppa_struct *) ref;
65         unsigned long flags;
66
67         spin_lock_irqsave(&arbitration_lock, flags);
68         if (dev->wanted) {
69                 parport_claim(dev->dev);
70                 got_it(dev);
71                 dev->wanted = 0;
72         }
73         spin_unlock_irqrestore(&arbitration_lock, flags);
74         return;
75 }
76
77 static int ppa_pb_claim(ppa_struct *dev)
78 {
79         unsigned long flags;
80         int res = 1;
81         spin_lock_irqsave(&arbitration_lock, flags);
82         if (parport_claim(dev->dev) == 0) {
83                 got_it(dev);
84                 res = 0;
85         }
86         dev->wanted = res;
87         spin_unlock_irqrestore(&arbitration_lock, flags);
88         return res;
89 }
90
91 static void ppa_pb_dismiss(ppa_struct *dev)
92 {
93         unsigned long flags;
94         int wanted;
95         spin_lock_irqsave(&arbitration_lock, flags);
96         wanted = dev->wanted;
97         dev->wanted = 0;
98         spin_unlock_irqrestore(&arbitration_lock, flags);
99         if (!wanted)
100                 parport_release(dev->dev);
101 }
102
103 static inline void ppa_pb_release(ppa_struct *dev)
104 {
105         parport_release(dev->dev);
106 }
107
108 /*
109  * Start of Chipset kludges
110  */
111
112 /* This is to give the ppa driver a way to modify the timings (and other
113  * parameters) by writing to the /proc/scsi/ppa/0 file.
114  * Very simple method really... (To simple, no error checking :( )
115  * Reason: Kernel hackers HATE having to unload and reload modules for
116  * testing...
117  * Also gives a method to use a script to obtain optimum timings (TODO)
118  */
119
120 static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
121 {
122         unsigned long x;
123
124         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
125                 x = simple_strtoul(buffer + 5, NULL, 0);
126                 dev->mode = x;
127                 return length;
128         }
129         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
130                 x = simple_strtoul(buffer + 10, NULL, 0);
131                 dev->recon_tmo = x;
132                 printk("ppa: recon_tmo set to %ld\n", x);
133                 return length;
134         }
135         printk("ppa /proc: invalid variable\n");
136         return (-EINVAL);
137 }
138
139 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
140 {
141         int len = 0;
142         ppa_struct *dev = ppa_dev(host);
143
144         if (inout)
145                 return ppa_proc_write(dev, buffer, length);
146
147         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
148         len +=
149             sprintf(buffer + len, "Parport : %s\n",
150                     dev->dev->port->name);
151         len +=
152             sprintf(buffer + len, "Mode    : %s\n",
153                     PPA_MODE_STRING[dev->mode]);
154 #if PPA_DEBUG > 0
155         len +=
156             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
157 #endif
158
159         /* Request for beyond end of buffer */
160         if (offset > length)
161                 return 0;
162
163         *start = buffer + offset;
164         len -= offset;
165         if (len > length)
166                 len = length;
167         return len;
168 }
169
170 static int device_check(ppa_struct *dev);
171
172 #if PPA_DEBUG > 0
173 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
174            y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
175 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
176 #else
177 static inline void ppa_fail(ppa_struct *dev, int error_code)
178 #endif
179 {
180         /* If we fail a device then we trash status / message bytes */
181         if (dev->cur_cmd) {
182                 dev->cur_cmd->result = error_code << 16;
183                 dev->failed = 1;
184         }
185 }
186
187 /*
188  * Wait for the high bit to be set.
189  * 
190  * In principle, this could be tied to an interrupt, but the adapter
191  * doesn't appear to be designed to support interrupts.  We spin on
192  * the 0x80 ready bit. 
193  */
194 static unsigned char ppa_wait(ppa_struct *dev)
195 {
196         int k;
197         unsigned short ppb = dev->base;
198         unsigned char r;
199
200         k = PPA_SPIN_TMO;
201         /* Wait for bit 6 and 7 - PJC */
202         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
203                 udelay(1);
204                 r = r_str(ppb);
205         }
206
207         /*
208          * return some status information.
209          * Semantics: 0xc0 = ZIP wants more data
210          *            0xd0 = ZIP wants to send more data
211          *            0xe0 = ZIP is expecting SCSI command data
212          *            0xf0 = end of transfer, ZIP is sending status
213          */
214         if (k)
215                 return (r & 0xf0);
216
217         /* Counter expired - Time out occurred */
218         ppa_fail(dev, DID_TIME_OUT);
219         printk("ppa timeout in ppa_wait\n");
220         return 0;               /* command timed out */
221 }
222
223 /*
224  * Clear EPP Timeout Bit 
225  */
226 static inline void epp_reset(unsigned short ppb)
227 {
228         int i;
229
230         i = r_str(ppb);
231         w_str(ppb, i);
232         w_str(ppb, i & 0xfe);
233 }
234
235 /* 
236  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
237  */
238 static inline void ecp_sync(ppa_struct *dev)
239 {
240         int i, ppb_hi = dev->dev->port->base_hi;
241
242         if (ppb_hi == 0)
243                 return;
244
245         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
246                 for (i = 0; i < 100; i++) {
247                         if (r_ecr(ppb_hi) & 0x01)
248                                 return;
249                         udelay(5);
250                 }
251                 printk("ppa: ECP sync failed as data still present in FIFO.\n");
252         }
253 }
254
255 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
256 {
257         int i;
258
259         for (i = len; i; i--) {
260                 w_dtr(base, *buffer++);
261                 w_ctr(base, 0xe);
262                 w_ctr(base, 0xc);
263         }
264         return 1;               /* All went well - we hope! */
265 }
266
267 static int ppa_byte_in(unsigned short base, char *buffer, int len)
268 {
269         int i;
270
271         for (i = len; i; i--) {
272                 *buffer++ = r_dtr(base);
273                 w_ctr(base, 0x27);
274                 w_ctr(base, 0x25);
275         }
276         return 1;               /* All went well - we hope! */
277 }
278
279 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
280 {
281         for (; len; len--) {
282                 unsigned char h;
283
284                 w_ctr(base, 0x4);
285                 h = r_str(base) & 0xf0;
286                 w_ctr(base, 0x6);
287                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
288         }
289         return 1;               /* All went well - we hope! */
290 }
291
292 static int ppa_out(ppa_struct *dev, char *buffer, int len)
293 {
294         int r;
295         unsigned short ppb = dev->base;
296
297         r = ppa_wait(dev);
298
299         if ((r & 0x50) != 0x40) {
300                 ppa_fail(dev, DID_ERROR);
301                 return 0;
302         }
303         switch (dev->mode) {
304         case PPA_NIBBLE:
305         case PPA_PS2:
306                 /* 8 bit output, with a loop */
307                 r = ppa_byte_out(ppb, buffer, len);
308                 break;
309
310         case PPA_EPP_32:
311         case PPA_EPP_16:
312         case PPA_EPP_8:
313                 epp_reset(ppb);
314                 w_ctr(ppb, 0x4);
315 #ifdef CONFIG_SCSI_IZIP_EPP16
316                 if (!(((long) buffer | len) & 0x01))
317                         outsw(ppb + 4, buffer, len >> 1);
318 #else
319                 if (!(((long) buffer | len) & 0x03))
320                         outsl(ppb + 4, buffer, len >> 2);
321 #endif
322                 else
323                         outsb(ppb + 4, buffer, len);
324                 w_ctr(ppb, 0xc);
325                 r = !(r_str(ppb) & 0x01);
326                 w_ctr(ppb, 0xc);
327                 ecp_sync(dev);
328                 break;
329
330         default:
331                 printk("PPA: bug in ppa_out()\n");
332                 r = 0;
333         }
334         return r;
335 }
336
337 static int ppa_in(ppa_struct *dev, char *buffer, int len)
338 {
339         int r;
340         unsigned short ppb = dev->base;
341
342         r = ppa_wait(dev);
343
344         if ((r & 0x50) != 0x50) {
345                 ppa_fail(dev, DID_ERROR);
346                 return 0;
347         }
348         switch (dev->mode) {
349         case PPA_NIBBLE:
350                 /* 4 bit input, with a loop */
351                 r = ppa_nibble_in(ppb, buffer, len);
352                 w_ctr(ppb, 0xc);
353                 break;
354
355         case PPA_PS2:
356                 /* 8 bit input, with a loop */
357                 w_ctr(ppb, 0x25);
358                 r = ppa_byte_in(ppb, buffer, len);
359                 w_ctr(ppb, 0x4);
360                 w_ctr(ppb, 0xc);
361                 break;
362
363         case PPA_EPP_32:
364         case PPA_EPP_16:
365         case PPA_EPP_8:
366                 epp_reset(ppb);
367                 w_ctr(ppb, 0x24);
368 #ifdef CONFIG_SCSI_IZIP_EPP16
369                 if (!(((long) buffer | len) & 0x01))
370                         insw(ppb + 4, buffer, len >> 1);
371 #else
372                 if (!(((long) buffer | len) & 0x03))
373                         insl(ppb + 4, buffer, len >> 2);
374 #endif
375                 else
376                         insb(ppb + 4, buffer, len);
377                 w_ctr(ppb, 0x2c);
378                 r = !(r_str(ppb) & 0x01);
379                 w_ctr(ppb, 0x2c);
380                 ecp_sync(dev);
381                 break;
382
383         default:
384                 printk("PPA: bug in ppa_ins()\n");
385                 r = 0;
386                 break;
387         }
388         return r;
389 }
390
391 /* end of ppa_io.h */
392 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
393 {
394         w_dtr(ppb, b);
395         w_ctr(ppb, 0xc);
396         w_ctr(ppb, 0xe);
397         w_ctr(ppb, 0xc);
398         w_ctr(ppb, 0x4);
399         w_ctr(ppb, 0xc);
400 }
401
402 static void ppa_disconnect(ppa_struct *dev)
403 {
404         unsigned short ppb = dev->base;
405
406         ppa_d_pulse(ppb, 0);
407         ppa_d_pulse(ppb, 0x3c);
408         ppa_d_pulse(ppb, 0x20);
409         ppa_d_pulse(ppb, 0xf);
410 }
411
412 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
413 {
414         w_dtr(ppb, b);
415         w_ctr(ppb, 0x4);
416         w_ctr(ppb, 0x6);
417         w_ctr(ppb, 0x4);
418         w_ctr(ppb, 0xc);
419 }
420
421 static inline void ppa_connect(ppa_struct *dev, int flag)
422 {
423         unsigned short ppb = dev->base;
424
425         ppa_c_pulse(ppb, 0);
426         ppa_c_pulse(ppb, 0x3c);
427         ppa_c_pulse(ppb, 0x20);
428         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
429                 ppa_c_pulse(ppb, 0xcf);
430         else
431                 ppa_c_pulse(ppb, 0x8f);
432 }
433
434 static int ppa_select(ppa_struct *dev, int target)
435 {
436         int k;
437         unsigned short ppb = dev->base;
438
439         /*
440          * Bit 6 (0x40) is the device selected bit.
441          * First we must wait till the current device goes off line...
442          */
443         k = PPA_SELECT_TMO;
444         do {
445                 k--;
446                 udelay(1);
447         } while ((r_str(ppb) & 0x40) && (k));
448         if (!k)
449                 return 0;
450
451         w_dtr(ppb, (1 << target));
452         w_ctr(ppb, 0xe);
453         w_ctr(ppb, 0xc);
454         w_dtr(ppb, 0x80);       /* This is NOT the initator */
455         w_ctr(ppb, 0x8);
456
457         k = PPA_SELECT_TMO;
458         do {
459                 k--;
460                 udelay(1);
461         }
462         while (!(r_str(ppb) & 0x40) && (k));
463         if (!k)
464                 return 0;
465
466         return 1;
467 }
468
469 /* 
470  * This is based on a trace of what the Iomega DOS 'guest' driver does.
471  * I've tried several different kinds of parallel ports with guest and
472  * coded this to react in the same ways that it does.
473  * 
474  * The return value from this function is just a hint about where the
475  * handshaking failed.
476  * 
477  */
478 static int ppa_init(ppa_struct *dev)
479 {
480         int retv;
481         unsigned short ppb = dev->base;
482
483         ppa_disconnect(dev);
484         ppa_connect(dev, CONNECT_NORMAL);
485
486         retv = 2;               /* Failed */
487
488         w_ctr(ppb, 0xe);
489         if ((r_str(ppb) & 0x08) == 0x08)
490                 retv--;
491
492         w_ctr(ppb, 0xc);
493         if ((r_str(ppb) & 0x08) == 0x00)
494                 retv--;
495
496         if (!retv)
497                 ppa_reset_pulse(ppb);
498         udelay(1000);           /* Allow devices to settle down */
499         ppa_disconnect(dev);
500         udelay(1000);           /* Another delay to allow devices to settle */
501
502         if (retv)
503                 return -EIO;
504
505         return device_check(dev);
506 }
507
508 static inline int ppa_send_command(struct scsi_cmnd *cmd)
509 {
510         ppa_struct *dev = ppa_dev(cmd->device->host);
511         int k;
512
513         w_ctr(dev->base, 0x0c);
514
515         for (k = 0; k < cmd->cmd_len; k++)
516                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
517                         return 0;
518         return 1;
519 }
520
521 /*
522  * The bulk flag enables some optimisations in the data transfer loops,
523  * it should be true for any command that transfers data in integral
524  * numbers of sectors.
525  * 
526  * The driver appears to remain stable if we speed up the parallel port
527  * i/o in this function, but not elsewhere.
528  */
529 static int ppa_completion(struct scsi_cmnd *cmd)
530 {
531         /* Return codes:
532          * -1     Error
533          *  0     Told to schedule
534          *  1     Finished data transfer
535          */
536         ppa_struct *dev = ppa_dev(cmd->device->host);
537         unsigned short ppb = dev->base;
538         unsigned long start_jiffies = jiffies;
539
540         unsigned char r, v;
541         int fast, bulk, status;
542
543         v = cmd->cmnd[0];
544         bulk = ((v == READ_6) ||
545                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
546
547         /*
548          * We only get here if the drive is ready to comunicate,
549          * hence no need for a full ppa_wait.
550          */
551         r = (r_str(ppb) & 0xf0);
552
553         while (r != (unsigned char) 0xf0) {
554                 /*
555                  * If we have been running for more than a full timer tick
556                  * then take a rest.
557                  */
558                 if (time_after(jiffies, start_jiffies + 1))
559                         return 0;
560
561                 if ((cmd->SCp.this_residual <= 0)) {
562                         ppa_fail(dev, DID_ERROR);
563                         return -1;      /* ERROR_RETURN */
564                 }
565
566                 /* On some hardware we have SCSI disconnected (6th bit low)
567                  * for about 100usecs. It is too expensive to wait a 
568                  * tick on every loop so we busy wait for no more than
569                  * 500usecs to give the drive a chance first. We do not 
570                  * change things for "normal" hardware since generally 
571                  * the 6th bit is always high.
572                  * This makes the CPU load higher on some hardware 
573                  * but otherwise we can not get more than 50K/secs 
574                  * on this problem hardware.
575                  */
576                 if ((r & 0xc0) != 0xc0) {
577                         /* Wait for reconnection should be no more than 
578                          * jiffy/2 = 5ms = 5000 loops
579                          */
580                         unsigned long k = dev->recon_tmo;
581                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
582                              k--)
583                                 udelay(1);
584
585                         if (!k)
586                                 return 0;
587                 }
588
589                 /* determine if we should use burst I/O */
590                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
591                     ? PPA_BURST_SIZE : 1;
592
593                 if (r == (unsigned char) 0xc0)
594                         status = ppa_out(dev, cmd->SCp.ptr, fast);
595                 else
596                         status = ppa_in(dev, cmd->SCp.ptr, fast);
597
598                 cmd->SCp.ptr += fast;
599                 cmd->SCp.this_residual -= fast;
600
601                 if (!status) {
602                         ppa_fail(dev, DID_BUS_BUSY);
603                         return -1;      /* ERROR_RETURN */
604                 }
605                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
606                         /* if scatter/gather, advance to the next segment */
607                         if (cmd->SCp.buffers_residual--) {
608                                 cmd->SCp.buffer++;
609                                 cmd->SCp.this_residual =
610                                     cmd->SCp.buffer->length;
611                                 cmd->SCp.ptr =
612                                     page_address(cmd->SCp.buffer->page) +
613                                     cmd->SCp.buffer->offset;
614                         }
615                 }
616                 /* Now check to see if the drive is ready to comunicate */
617                 r = (r_str(ppb) & 0xf0);
618                 /* If not, drop back down to the scheduler and wait a timer tick */
619                 if (!(r & 0x80))
620                         return 0;
621         }
622         return 1;               /* FINISH_RETURN */
623 }
624
625 /*
626  * Since the PPA itself doesn't generate interrupts, we use
627  * the scheduler's task queue to generate a stream of call-backs and
628  * complete the request when the drive is ready.
629  */
630 static void ppa_interrupt(struct work_struct *work)
631 {
632         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
633         struct scsi_cmnd *cmd = dev->cur_cmd;
634
635         if (!cmd) {
636                 printk("PPA: bug in ppa_interrupt\n");
637                 return;
638         }
639         if (ppa_engine(dev, cmd)) {
640                 schedule_delayed_work(&dev->ppa_tq, 1);
641                 return;
642         }
643         /* Command must of completed hence it is safe to let go... */
644 #if PPA_DEBUG > 0
645         switch ((cmd->result >> 16) & 0xff) {
646         case DID_OK:
647                 break;
648         case DID_NO_CONNECT:
649                 printk("ppa: no device at SCSI ID %i\n", cmd->device->target);
650                 break;
651         case DID_BUS_BUSY:
652                 printk("ppa: BUS BUSY - EPP timeout detected\n");
653                 break;
654         case DID_TIME_OUT:
655                 printk("ppa: unknown timeout\n");
656                 break;
657         case DID_ABORT:
658                 printk("ppa: told to abort\n");
659                 break;
660         case DID_PARITY:
661                 printk("ppa: parity error (???)\n");
662                 break;
663         case DID_ERROR:
664                 printk("ppa: internal driver error\n");
665                 break;
666         case DID_RESET:
667                 printk("ppa: told to reset device\n");
668                 break;
669         case DID_BAD_INTR:
670                 printk("ppa: bad interrupt (???)\n");
671                 break;
672         default:
673                 printk("ppa: bad return code (%02x)\n",
674                        (cmd->result >> 16) & 0xff);
675         }
676 #endif
677
678         if (cmd->SCp.phase > 1)
679                 ppa_disconnect(dev);
680
681         ppa_pb_dismiss(dev);
682
683         dev->cur_cmd = NULL;
684
685         cmd->scsi_done(cmd);
686 }
687
688 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
689 {
690         unsigned short ppb = dev->base;
691         unsigned char l = 0, h = 0;
692         int retv;
693
694         /* First check for any errors that may of occurred
695          * Here we check for internal errors
696          */
697         if (dev->failed)
698                 return 0;
699
700         switch (cmd->SCp.phase) {
701         case 0:         /* Phase 0 - Waiting for parport */
702                 if (time_after(jiffies, dev->jstart + HZ)) {
703                         /*
704                          * We waited more than a second
705                          * for parport to call us
706                          */
707                         ppa_fail(dev, DID_BUS_BUSY);
708                         return 0;
709                 }
710                 return 1;       /* wait until ppa_wakeup claims parport */
711         case 1:         /* Phase 1 - Connected */
712                 {               /* Perform a sanity check for cable unplugged */
713                         int retv = 2;   /* Failed */
714
715                         ppa_connect(dev, CONNECT_EPP_MAYBE);
716
717                         w_ctr(ppb, 0xe);
718                         if ((r_str(ppb) & 0x08) == 0x08)
719                                 retv--;
720
721                         w_ctr(ppb, 0xc);
722                         if ((r_str(ppb) & 0x08) == 0x00)
723                                 retv--;
724
725                         if (retv) {
726                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
727                                         printk
728                                             ("ppa: Parallel port cable is unplugged!!\n");
729                                         ppa_fail(dev, DID_BUS_BUSY);
730                                         return 0;
731                                 } else {
732                                         ppa_disconnect(dev);
733                                         return 1;       /* Try again in a jiffy */
734                                 }
735                         }
736                         cmd->SCp.phase++;
737                 }
738
739         case 2:         /* Phase 2 - We are now talking to the scsi bus */
740                 if (!ppa_select(dev, scmd_id(cmd))) {
741                         ppa_fail(dev, DID_NO_CONNECT);
742                         return 0;
743                 }
744                 cmd->SCp.phase++;
745
746         case 3:         /* Phase 3 - Ready to accept a command */
747                 w_ctr(ppb, 0x0c);
748                 if (!(r_str(ppb) & 0x80))
749                         return 1;
750
751                 if (!ppa_send_command(cmd))
752                         return 0;
753                 cmd->SCp.phase++;
754
755         case 4:         /* Phase 4 - Setup scatter/gather buffers */
756                 if (cmd->use_sg) {
757                         /* if many buffers are available, start filling the first */
758                         cmd->SCp.buffer =
759                             (struct scatterlist *) cmd->request_buffer;
760                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
761                         cmd->SCp.ptr =
762                             page_address(cmd->SCp.buffer->page) +
763                             cmd->SCp.buffer->offset;
764                 } else {
765                         /* else fill the only available buffer */
766                         cmd->SCp.buffer = NULL;
767                         cmd->SCp.this_residual = cmd->request_bufflen;
768                         cmd->SCp.ptr = cmd->request_buffer;
769                 }
770                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
771                 cmd->SCp.phase++;
772
773         case 5:         /* Phase 5 - Data transfer stage */
774                 w_ctr(ppb, 0x0c);
775                 if (!(r_str(ppb) & 0x80))
776                         return 1;
777
778                 retv = ppa_completion(cmd);
779                 if (retv == -1)
780                         return 0;
781                 if (retv == 0)
782                         return 1;
783                 cmd->SCp.phase++;
784
785         case 6:         /* Phase 6 - Read status/message */
786                 cmd->result = DID_OK << 16;
787                 /* Check for data overrun */
788                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
789                         ppa_fail(dev, DID_ERROR);
790                         return 0;
791                 }
792                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
793                         /* Check for optional message byte */
794                         if (ppa_wait(dev) == (unsigned char) 0xf0)
795                                 ppa_in(dev, &h, 1);
796                         cmd->result =
797                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
798                 }
799                 return 0;       /* Finished */
800                 break;
801
802         default:
803                 printk("ppa: Invalid scsi phase\n");
804         }
805         return 0;
806 }
807
808 static int ppa_queuecommand(struct scsi_cmnd *cmd,
809                 void (*done) (struct scsi_cmnd *))
810 {
811         ppa_struct *dev = ppa_dev(cmd->device->host);
812
813         if (dev->cur_cmd) {
814                 printk("PPA: bug in ppa_queuecommand\n");
815                 return 0;
816         }
817         dev->failed = 0;
818         dev->jstart = jiffies;
819         dev->cur_cmd = cmd;
820         cmd->scsi_done = done;
821         cmd->result = DID_ERROR << 16;  /* default return code */
822         cmd->SCp.phase = 0;     /* bus free */
823
824         schedule_delayed_work(&dev->ppa_tq, 0);
825
826         ppa_pb_claim(dev);
827
828         return 0;
829 }
830
831 /*
832  * Apparently the disk->capacity attribute is off by 1 sector 
833  * for all disk drives.  We add the one here, but it should really
834  * be done in sd.c.  Even if it gets fixed there, this will still
835  * work.
836  */
837 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
838               sector_t capacity, int ip[])
839 {
840         ip[0] = 0x40;
841         ip[1] = 0x20;
842         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
843         if (ip[2] > 1024) {
844                 ip[0] = 0xff;
845                 ip[1] = 0x3f;
846                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
847                 if (ip[2] > 1023)
848                         ip[2] = 1023;
849         }
850         return 0;
851 }
852
853 static int ppa_abort(struct scsi_cmnd *cmd)
854 {
855         ppa_struct *dev = ppa_dev(cmd->device->host);
856         /*
857          * There is no method for aborting commands since Iomega
858          * have tied the SCSI_MESSAGE line high in the interface
859          */
860
861         switch (cmd->SCp.phase) {
862         case 0:         /* Do not have access to parport */
863         case 1:         /* Have not connected to interface */
864                 dev->cur_cmd = NULL;    /* Forget the problem */
865                 return SUCCESS;
866                 break;
867         default:                /* SCSI command sent, can not abort */
868                 return FAILED;
869                 break;
870         }
871 }
872
873 static void ppa_reset_pulse(unsigned int base)
874 {
875         w_dtr(base, 0x40);
876         w_ctr(base, 0x8);
877         udelay(30);
878         w_ctr(base, 0xc);
879 }
880
881 static int ppa_reset(struct scsi_cmnd *cmd)
882 {
883         ppa_struct *dev = ppa_dev(cmd->device->host);
884
885         if (cmd->SCp.phase)
886                 ppa_disconnect(dev);
887         dev->cur_cmd = NULL;    /* Forget the problem */
888
889         ppa_connect(dev, CONNECT_NORMAL);
890         ppa_reset_pulse(dev->base);
891         mdelay(1);              /* device settle delay */
892         ppa_disconnect(dev);
893         mdelay(1);              /* device settle delay */
894         return SUCCESS;
895 }
896
897 static int device_check(ppa_struct *dev)
898 {
899         /* This routine looks for a device and then attempts to use EPP
900            to send a command. If all goes as planned then EPP is available. */
901
902         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
903         int loop, old_mode, status, k, ppb = dev->base;
904         unsigned char l;
905
906         old_mode = dev->mode;
907         for (loop = 0; loop < 8; loop++) {
908                 /* Attempt to use EPP for Test Unit Ready */
909                 if ((ppb & 0x0007) == 0x0000)
910                         dev->mode = PPA_EPP_32;
911
912               second_pass:
913                 ppa_connect(dev, CONNECT_EPP_MAYBE);
914                 /* Select SCSI device */
915                 if (!ppa_select(dev, loop)) {
916                         ppa_disconnect(dev);
917                         continue;
918                 }
919                 printk("ppa: Found device at ID %i, Attempting to use %s\n",
920                        loop, PPA_MODE_STRING[dev->mode]);
921
922                 /* Send SCSI command */
923                 status = 1;
924                 w_ctr(ppb, 0x0c);
925                 for (l = 0; (l < 6) && (status); l++)
926                         status = ppa_out(dev, cmd, 1);
927
928                 if (!status) {
929                         ppa_disconnect(dev);
930                         ppa_connect(dev, CONNECT_EPP_MAYBE);
931                         w_dtr(ppb, 0x40);
932                         w_ctr(ppb, 0x08);
933                         udelay(30);
934                         w_ctr(ppb, 0x0c);
935                         udelay(1000);
936                         ppa_disconnect(dev);
937                         udelay(1000);
938                         if (dev->mode == PPA_EPP_32) {
939                                 dev->mode = old_mode;
940                                 goto second_pass;
941                         }
942                         return -EIO;
943                 }
944                 w_ctr(ppb, 0x0c);
945                 k = 1000000;    /* 1 Second */
946                 do {
947                         l = r_str(ppb);
948                         k--;
949                         udelay(1);
950                 } while (!(l & 0x80) && (k));
951
952                 l &= 0xf0;
953
954                 if (l != 0xf0) {
955                         ppa_disconnect(dev);
956                         ppa_connect(dev, CONNECT_EPP_MAYBE);
957                         ppa_reset_pulse(ppb);
958                         udelay(1000);
959                         ppa_disconnect(dev);
960                         udelay(1000);
961                         if (dev->mode == PPA_EPP_32) {
962                                 dev->mode = old_mode;
963                                 goto second_pass;
964                         }
965                         return -EIO;
966                 }
967                 ppa_disconnect(dev);
968                 printk("ppa: Communication established with ID %i using %s\n",
969                        loop, PPA_MODE_STRING[dev->mode]);
970                 ppa_connect(dev, CONNECT_EPP_MAYBE);
971                 ppa_reset_pulse(ppb);
972                 udelay(1000);
973                 ppa_disconnect(dev);
974                 udelay(1000);
975                 return 0;
976         }
977         return -ENODEV;
978 }
979
980 static int ppa_adjust_queue(struct scsi_device *device)
981 {
982         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
983         return 0;
984 }
985
986 static struct scsi_host_template ppa_template = {
987         .module                 = THIS_MODULE,
988         .proc_name              = "ppa",
989         .proc_info              = ppa_proc_info,
990         .name                   = "Iomega VPI0 (ppa) interface",
991         .queuecommand           = ppa_queuecommand,
992         .eh_abort_handler       = ppa_abort,
993         .eh_bus_reset_handler   = ppa_reset,
994         .eh_host_reset_handler  = ppa_reset,
995         .bios_param             = ppa_biosparam,
996         .this_id                = -1,
997         .sg_tablesize           = SG_ALL,
998         .cmd_per_lun            = 1,
999         .use_clustering         = ENABLE_CLUSTERING,
1000         .can_queue              = 1,
1001         .slave_alloc            = ppa_adjust_queue,
1002 };
1003
1004 /***************************************************************************
1005  *                   Parallel port probing routines                        *
1006  ***************************************************************************/
1007
1008 static LIST_HEAD(ppa_hosts);
1009
1010 static int __ppa_attach(struct parport *pb)
1011 {
1012         struct Scsi_Host *host;
1013         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1014         DEFINE_WAIT(wait);
1015         ppa_struct *dev;
1016         int ports;
1017         int modes, ppb, ppb_hi;
1018         int err = -ENOMEM;
1019
1020         dev = kmalloc(sizeof(ppa_struct), GFP_KERNEL);
1021         if (!dev)
1022                 return -ENOMEM;
1023         memset(dev, 0, sizeof(ppa_struct));
1024         dev->base = -1;
1025         dev->mode = PPA_AUTODETECT;
1026         dev->recon_tmo = PPA_RECON_TMO;
1027         init_waitqueue_head(&waiting);
1028         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1029                                             NULL, 0, dev);
1030
1031         if (!dev->dev)
1032                 goto out;
1033
1034         /* Claim the bus so it remembers what we do to the control
1035          * registers. [ CTR and ECP ]
1036          */
1037         err = -EBUSY;
1038         dev->waiting = &waiting;
1039         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1040         if (ppa_pb_claim(dev))
1041                 schedule_timeout(3 * HZ);
1042         if (dev->wanted) {
1043                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1044                                 "a pardevice is owning the port for too long "
1045                                 "time!\n", pb->number);
1046                 ppa_pb_dismiss(dev);
1047                 dev->waiting = NULL;
1048                 finish_wait(&waiting, &wait);
1049                 goto out1;
1050         }
1051         dev->waiting = NULL;
1052         finish_wait(&waiting, &wait);
1053         ppb = dev->base = dev->dev->port->base;
1054         ppb_hi = dev->dev->port->base_hi;
1055         w_ctr(ppb, 0x0c);
1056         modes = dev->dev->port->modes;
1057
1058         /* Mode detection works up the chain of speed
1059          * This avoids a nasty if-then-else-if-... tree
1060          */
1061         dev->mode = PPA_NIBBLE;
1062
1063         if (modes & PARPORT_MODE_TRISTATE)
1064                 dev->mode = PPA_PS2;
1065
1066         if (modes & PARPORT_MODE_ECP) {
1067                 w_ecr(ppb_hi, 0x20);
1068                 dev->mode = PPA_PS2;
1069         }
1070         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1071                 w_ecr(ppb_hi, 0x80);
1072
1073         /* Done configuration */
1074
1075         err = ppa_init(dev);
1076         ppa_pb_release(dev);
1077
1078         if (err)
1079                 goto out1;
1080
1081         /* now the glue ... */
1082         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1083                 ports = 3;
1084         else
1085                 ports = 8;
1086
1087         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1088
1089         err = -ENOMEM;
1090         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1091         if (!host)
1092                 goto out1;
1093         host->io_port = pb->base;
1094         host->n_io_port = ports;
1095         host->dma_channel = -1;
1096         host->unique_id = pb->number;
1097         *(ppa_struct **)&host->hostdata = dev;
1098         dev->host = host;
1099         list_add_tail(&dev->list, &ppa_hosts);
1100         err = scsi_add_host(host, NULL);
1101         if (err)
1102                 goto out2;
1103         scsi_scan_host(host);
1104         return 0;
1105 out2:
1106         list_del_init(&dev->list);
1107         scsi_host_put(host);
1108 out1:
1109         parport_unregister_device(dev->dev);
1110 out:
1111         kfree(dev);
1112         return err;
1113 }
1114
1115 static void ppa_attach(struct parport *pb)
1116 {
1117         __ppa_attach(pb);
1118 }
1119
1120 static void ppa_detach(struct parport *pb)
1121 {
1122         ppa_struct *dev;
1123         list_for_each_entry(dev, &ppa_hosts, list) {
1124                 if (dev->dev->port == pb) {
1125                         list_del_init(&dev->list);
1126                         scsi_remove_host(dev->host);
1127                         scsi_host_put(dev->host);
1128                         parport_unregister_device(dev->dev);
1129                         kfree(dev);
1130                         break;
1131                 }
1132         }
1133 }
1134
1135 static struct parport_driver ppa_driver = {
1136         .name   = "ppa",
1137         .attach = ppa_attach,
1138         .detach = ppa_detach,
1139 };
1140
1141 static int __init ppa_driver_init(void)
1142 {
1143         printk("ppa: Version %s\n", PPA_VERSION);
1144         return parport_register_driver(&ppa_driver);
1145 }
1146
1147 static void __exit ppa_driver_exit(void)
1148 {
1149         parport_unregister_driver(&ppa_driver);
1150 }
1151
1152 module_init(ppa_driver_init);
1153 module_exit(ppa_driver_exit);
1154 MODULE_LICENSE("GPL");