tty: n_hdlc add buffer flushing
[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  */
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(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
133                 return length;
134         }
135         printk(KERN_WARNING "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, __func__, __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(KERN_WARNING "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(KERN_WARNING "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(KERN_ERR "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(KERN_ERR "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 = sg_virt(cmd->SCp.buffer);
612                         }
613                 }
614                 /* Now check to see if the drive is ready to comunicate */
615                 r = (r_str(ppb) & 0xf0);
616                 /* If not, drop back down to the scheduler and wait a timer tick */
617                 if (!(r & 0x80))
618                         return 0;
619         }
620         return 1;               /* FINISH_RETURN */
621 }
622
623 /*
624  * Since the PPA itself doesn't generate interrupts, we use
625  * the scheduler's task queue to generate a stream of call-backs and
626  * complete the request when the drive is ready.
627  */
628 static void ppa_interrupt(struct work_struct *work)
629 {
630         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
631         struct scsi_cmnd *cmd = dev->cur_cmd;
632
633         if (!cmd) {
634                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
635                 return;
636         }
637         if (ppa_engine(dev, cmd)) {
638                 schedule_delayed_work(&dev->ppa_tq, 1);
639                 return;
640         }
641         /* Command must of completed hence it is safe to let go... */
642 #if PPA_DEBUG > 0
643         switch ((cmd->result >> 16) & 0xff) {
644         case DID_OK:
645                 break;
646         case DID_NO_CONNECT:
647                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
648                 break;
649         case DID_BUS_BUSY:
650                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
651                 break;
652         case DID_TIME_OUT:
653                 printk(KERN_DEBUG "ppa: unknown timeout\n");
654                 break;
655         case DID_ABORT:
656                 printk(KERN_DEBUG "ppa: told to abort\n");
657                 break;
658         case DID_PARITY:
659                 printk(KERN_DEBUG "ppa: parity error (???)\n");
660                 break;
661         case DID_ERROR:
662                 printk(KERN_DEBUG "ppa: internal driver error\n");
663                 break;
664         case DID_RESET:
665                 printk(KERN_DEBUG "ppa: told to reset device\n");
666                 break;
667         case DID_BAD_INTR:
668                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
669                 break;
670         default:
671                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
672                        (cmd->result >> 16) & 0xff);
673         }
674 #endif
675
676         if (cmd->SCp.phase > 1)
677                 ppa_disconnect(dev);
678
679         ppa_pb_dismiss(dev);
680
681         dev->cur_cmd = NULL;
682
683         cmd->scsi_done(cmd);
684 }
685
686 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
687 {
688         unsigned short ppb = dev->base;
689         unsigned char l = 0, h = 0;
690         int retv;
691
692         /* First check for any errors that may of occurred
693          * Here we check for internal errors
694          */
695         if (dev->failed)
696                 return 0;
697
698         switch (cmd->SCp.phase) {
699         case 0:         /* Phase 0 - Waiting for parport */
700                 if (time_after(jiffies, dev->jstart + HZ)) {
701                         /*
702                          * We waited more than a second
703                          * for parport to call us
704                          */
705                         ppa_fail(dev, DID_BUS_BUSY);
706                         return 0;
707                 }
708                 return 1;       /* wait until ppa_wakeup claims parport */
709         case 1:         /* Phase 1 - Connected */
710                 {               /* Perform a sanity check for cable unplugged */
711                         int retv = 2;   /* Failed */
712
713                         ppa_connect(dev, CONNECT_EPP_MAYBE);
714
715                         w_ctr(ppb, 0xe);
716                         if ((r_str(ppb) & 0x08) == 0x08)
717                                 retv--;
718
719                         w_ctr(ppb, 0xc);
720                         if ((r_str(ppb) & 0x08) == 0x00)
721                                 retv--;
722
723                         if (retv) {
724                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
725                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
726                                         ppa_fail(dev, DID_BUS_BUSY);
727                                         return 0;
728                                 } else {
729                                         ppa_disconnect(dev);
730                                         return 1;       /* Try again in a jiffy */
731                                 }
732                         }
733                         cmd->SCp.phase++;
734                 }
735
736         case 2:         /* Phase 2 - We are now talking to the scsi bus */
737                 if (!ppa_select(dev, scmd_id(cmd))) {
738                         ppa_fail(dev, DID_NO_CONNECT);
739                         return 0;
740                 }
741                 cmd->SCp.phase++;
742
743         case 3:         /* Phase 3 - Ready to accept a command */
744                 w_ctr(ppb, 0x0c);
745                 if (!(r_str(ppb) & 0x80))
746                         return 1;
747
748                 if (!ppa_send_command(cmd))
749                         return 0;
750                 cmd->SCp.phase++;
751
752         case 4:         /* Phase 4 - Setup scatter/gather buffers */
753                 if (scsi_bufflen(cmd)) {
754                         cmd->SCp.buffer = scsi_sglist(cmd);
755                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
756                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
757                 } else {
758                         cmd->SCp.buffer = NULL;
759                         cmd->SCp.this_residual = 0;
760                         cmd->SCp.ptr = NULL;
761                 }
762                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
763                 cmd->SCp.phase++;
764
765         case 5:         /* Phase 5 - Data transfer stage */
766                 w_ctr(ppb, 0x0c);
767                 if (!(r_str(ppb) & 0x80))
768                         return 1;
769
770                 retv = ppa_completion(cmd);
771                 if (retv == -1)
772                         return 0;
773                 if (retv == 0)
774                         return 1;
775                 cmd->SCp.phase++;
776
777         case 6:         /* Phase 6 - Read status/message */
778                 cmd->result = DID_OK << 16;
779                 /* Check for data overrun */
780                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
781                         ppa_fail(dev, DID_ERROR);
782                         return 0;
783                 }
784                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
785                         /* Check for optional message byte */
786                         if (ppa_wait(dev) == (unsigned char) 0xf0)
787                                 ppa_in(dev, &h, 1);
788                         cmd->result =
789                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
790                 }
791                 return 0;       /* Finished */
792                 break;
793
794         default:
795                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
796         }
797         return 0;
798 }
799
800 static int ppa_queuecommand(struct scsi_cmnd *cmd,
801                 void (*done) (struct scsi_cmnd *))
802 {
803         ppa_struct *dev = ppa_dev(cmd->device->host);
804
805         if (dev->cur_cmd) {
806                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
807                 return 0;
808         }
809         dev->failed = 0;
810         dev->jstart = jiffies;
811         dev->cur_cmd = cmd;
812         cmd->scsi_done = done;
813         cmd->result = DID_ERROR << 16;  /* default return code */
814         cmd->SCp.phase = 0;     /* bus free */
815
816         schedule_delayed_work(&dev->ppa_tq, 0);
817
818         ppa_pb_claim(dev);
819
820         return 0;
821 }
822
823 /*
824  * Apparently the disk->capacity attribute is off by 1 sector 
825  * for all disk drives.  We add the one here, but it should really
826  * be done in sd.c.  Even if it gets fixed there, this will still
827  * work.
828  */
829 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
830               sector_t capacity, int ip[])
831 {
832         ip[0] = 0x40;
833         ip[1] = 0x20;
834         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
835         if (ip[2] > 1024) {
836                 ip[0] = 0xff;
837                 ip[1] = 0x3f;
838                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
839                 if (ip[2] > 1023)
840                         ip[2] = 1023;
841         }
842         return 0;
843 }
844
845 static int ppa_abort(struct scsi_cmnd *cmd)
846 {
847         ppa_struct *dev = ppa_dev(cmd->device->host);
848         /*
849          * There is no method for aborting commands since Iomega
850          * have tied the SCSI_MESSAGE line high in the interface
851          */
852
853         switch (cmd->SCp.phase) {
854         case 0:         /* Do not have access to parport */
855         case 1:         /* Have not connected to interface */
856                 dev->cur_cmd = NULL;    /* Forget the problem */
857                 return SUCCESS;
858                 break;
859         default:                /* SCSI command sent, can not abort */
860                 return FAILED;
861                 break;
862         }
863 }
864
865 static void ppa_reset_pulse(unsigned int base)
866 {
867         w_dtr(base, 0x40);
868         w_ctr(base, 0x8);
869         udelay(30);
870         w_ctr(base, 0xc);
871 }
872
873 static int ppa_reset(struct scsi_cmnd *cmd)
874 {
875         ppa_struct *dev = ppa_dev(cmd->device->host);
876
877         if (cmd->SCp.phase)
878                 ppa_disconnect(dev);
879         dev->cur_cmd = NULL;    /* Forget the problem */
880
881         ppa_connect(dev, CONNECT_NORMAL);
882         ppa_reset_pulse(dev->base);
883         mdelay(1);              /* device settle delay */
884         ppa_disconnect(dev);
885         mdelay(1);              /* device settle delay */
886         return SUCCESS;
887 }
888
889 static int device_check(ppa_struct *dev)
890 {
891         /* This routine looks for a device and then attempts to use EPP
892            to send a command. If all goes as planned then EPP is available. */
893
894         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
895         int loop, old_mode, status, k, ppb = dev->base;
896         unsigned char l;
897
898         old_mode = dev->mode;
899         for (loop = 0; loop < 8; loop++) {
900                 /* Attempt to use EPP for Test Unit Ready */
901                 if ((ppb & 0x0007) == 0x0000)
902                         dev->mode = PPA_EPP_32;
903
904 second_pass:
905                 ppa_connect(dev, CONNECT_EPP_MAYBE);
906                 /* Select SCSI device */
907                 if (!ppa_select(dev, loop)) {
908                         ppa_disconnect(dev);
909                         continue;
910                 }
911                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
912                        loop, PPA_MODE_STRING[dev->mode]);
913
914                 /* Send SCSI command */
915                 status = 1;
916                 w_ctr(ppb, 0x0c);
917                 for (l = 0; (l < 6) && (status); l++)
918                         status = ppa_out(dev, cmd, 1);
919
920                 if (!status) {
921                         ppa_disconnect(dev);
922                         ppa_connect(dev, CONNECT_EPP_MAYBE);
923                         w_dtr(ppb, 0x40);
924                         w_ctr(ppb, 0x08);
925                         udelay(30);
926                         w_ctr(ppb, 0x0c);
927                         udelay(1000);
928                         ppa_disconnect(dev);
929                         udelay(1000);
930                         if (dev->mode == PPA_EPP_32) {
931                                 dev->mode = old_mode;
932                                 goto second_pass;
933                         }
934                         return -EIO;
935                 }
936                 w_ctr(ppb, 0x0c);
937                 k = 1000000;    /* 1 Second */
938                 do {
939                         l = r_str(ppb);
940                         k--;
941                         udelay(1);
942                 } while (!(l & 0x80) && (k));
943
944                 l &= 0xf0;
945
946                 if (l != 0xf0) {
947                         ppa_disconnect(dev);
948                         ppa_connect(dev, CONNECT_EPP_MAYBE);
949                         ppa_reset_pulse(ppb);
950                         udelay(1000);
951                         ppa_disconnect(dev);
952                         udelay(1000);
953                         if (dev->mode == PPA_EPP_32) {
954                                 dev->mode = old_mode;
955                                 goto second_pass;
956                         }
957                         return -EIO;
958                 }
959                 ppa_disconnect(dev);
960                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
961                        loop, PPA_MODE_STRING[dev->mode]);
962                 ppa_connect(dev, CONNECT_EPP_MAYBE);
963                 ppa_reset_pulse(ppb);
964                 udelay(1000);
965                 ppa_disconnect(dev);
966                 udelay(1000);
967                 return 0;
968         }
969         return -ENODEV;
970 }
971
972 static int ppa_adjust_queue(struct scsi_device *device)
973 {
974         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
975         return 0;
976 }
977
978 static struct scsi_host_template ppa_template = {
979         .module                 = THIS_MODULE,
980         .proc_name              = "ppa",
981         .proc_info              = ppa_proc_info,
982         .name                   = "Iomega VPI0 (ppa) interface",
983         .queuecommand           = ppa_queuecommand,
984         .eh_abort_handler       = ppa_abort,
985         .eh_bus_reset_handler   = ppa_reset,
986         .eh_host_reset_handler  = ppa_reset,
987         .bios_param             = ppa_biosparam,
988         .this_id                = -1,
989         .sg_tablesize           = SG_ALL,
990         .cmd_per_lun            = 1,
991         .use_clustering         = ENABLE_CLUSTERING,
992         .can_queue              = 1,
993         .slave_alloc            = ppa_adjust_queue,
994 };
995
996 /***************************************************************************
997  *                   Parallel port probing routines                        *
998  ***************************************************************************/
999
1000 static LIST_HEAD(ppa_hosts);
1001
1002 static int __ppa_attach(struct parport *pb)
1003 {
1004         struct Scsi_Host *host;
1005         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1006         DEFINE_WAIT(wait);
1007         ppa_struct *dev;
1008         int ports;
1009         int modes, ppb, ppb_hi;
1010         int err = -ENOMEM;
1011
1012         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1013         if (!dev)
1014                 return -ENOMEM;
1015         dev->base = -1;
1016         dev->mode = PPA_AUTODETECT;
1017         dev->recon_tmo = PPA_RECON_TMO;
1018         init_waitqueue_head(&waiting);
1019         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1020                                             NULL, 0, dev);
1021
1022         if (!dev->dev)
1023                 goto out;
1024
1025         /* Claim the bus so it remembers what we do to the control
1026          * registers. [ CTR and ECP ]
1027          */
1028         err = -EBUSY;
1029         dev->waiting = &waiting;
1030         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1031         if (ppa_pb_claim(dev))
1032                 schedule_timeout(3 * HZ);
1033         if (dev->wanted) {
1034                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1035                                 "a pardevice is owning the port for too long "
1036                                 "time!\n", pb->number);
1037                 ppa_pb_dismiss(dev);
1038                 dev->waiting = NULL;
1039                 finish_wait(&waiting, &wait);
1040                 goto out1;
1041         }
1042         dev->waiting = NULL;
1043         finish_wait(&waiting, &wait);
1044         ppb = dev->base = dev->dev->port->base;
1045         ppb_hi = dev->dev->port->base_hi;
1046         w_ctr(ppb, 0x0c);
1047         modes = dev->dev->port->modes;
1048
1049         /* Mode detection works up the chain of speed
1050          * This avoids a nasty if-then-else-if-... tree
1051          */
1052         dev->mode = PPA_NIBBLE;
1053
1054         if (modes & PARPORT_MODE_TRISTATE)
1055                 dev->mode = PPA_PS2;
1056
1057         if (modes & PARPORT_MODE_ECP) {
1058                 w_ecr(ppb_hi, 0x20);
1059                 dev->mode = PPA_PS2;
1060         }
1061         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1062                 w_ecr(ppb_hi, 0x80);
1063
1064         /* Done configuration */
1065
1066         err = ppa_init(dev);
1067         ppa_pb_release(dev);
1068
1069         if (err)
1070                 goto out1;
1071
1072         /* now the glue ... */
1073         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1074                 ports = 3;
1075         else
1076                 ports = 8;
1077
1078         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1079
1080         err = -ENOMEM;
1081         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1082         if (!host)
1083                 goto out1;
1084         host->io_port = pb->base;
1085         host->n_io_port = ports;
1086         host->dma_channel = -1;
1087         host->unique_id = pb->number;
1088         *(ppa_struct **)&host->hostdata = dev;
1089         dev->host = host;
1090         list_add_tail(&dev->list, &ppa_hosts);
1091         err = scsi_add_host(host, NULL);
1092         if (err)
1093                 goto out2;
1094         scsi_scan_host(host);
1095         return 0;
1096 out2:
1097         list_del_init(&dev->list);
1098         scsi_host_put(host);
1099 out1:
1100         parport_unregister_device(dev->dev);
1101 out:
1102         kfree(dev);
1103         return err;
1104 }
1105
1106 static void ppa_attach(struct parport *pb)
1107 {
1108         __ppa_attach(pb);
1109 }
1110
1111 static void ppa_detach(struct parport *pb)
1112 {
1113         ppa_struct *dev;
1114         list_for_each_entry(dev, &ppa_hosts, list) {
1115                 if (dev->dev->port == pb) {
1116                         list_del_init(&dev->list);
1117                         scsi_remove_host(dev->host);
1118                         scsi_host_put(dev->host);
1119                         parport_unregister_device(dev->dev);
1120                         kfree(dev);
1121                         break;
1122                 }
1123         }
1124 }
1125
1126 static struct parport_driver ppa_driver = {
1127         .name   = "ppa",
1128         .attach = ppa_attach,
1129         .detach = ppa_detach,
1130 };
1131
1132 static int __init ppa_driver_init(void)
1133 {
1134         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1135         return parport_register_driver(&ppa_driver);
1136 }
1137
1138 static void __exit ppa_driver_exit(void)
1139 {
1140         parport_unregister_driver(&ppa_driver);
1141 }
1142
1143 module_init(ppa_driver_init);
1144 module_exit(ppa_driver_exit);
1145 MODULE_LICENSE("GPL");