config: tegra3: enable /dev mount with ACL
[linux-2.6.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_proc_write(ppa_struct *dev, char *buffer, int length)
122 {
123         unsigned long x;
124
125         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
126                 x = simple_strtoul(buffer + 5, NULL, 0);
127                 dev->mode = x;
128                 return length;
129         }
130         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
131                 x = simple_strtoul(buffer + 10, NULL, 0);
132                 dev->recon_tmo = x;
133                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
134                 return length;
135         }
136         printk(KERN_WARNING "ppa /proc: invalid variable\n");
137         return -EINVAL;
138 }
139
140 static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
141 {
142         int len = 0;
143         ppa_struct *dev = ppa_dev(host);
144
145         if (inout)
146                 return ppa_proc_write(dev, buffer, length);
147
148         len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
149         len +=
150             sprintf(buffer + len, "Parport : %s\n",
151                     dev->dev->port->name);
152         len +=
153             sprintf(buffer + len, "Mode    : %s\n",
154                     PPA_MODE_STRING[dev->mode]);
155 #if PPA_DEBUG > 0
156         len +=
157             sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
158 #endif
159
160         /* Request for beyond end of buffer */
161         if (offset > length)
162                 return 0;
163
164         *start = buffer + offset;
165         len -= offset;
166         if (len > length)
167                 len = length;
168         return len;
169 }
170
171 static int device_check(ppa_struct *dev);
172
173 #if PPA_DEBUG > 0
174 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
175            y, __func__, __LINE__); ppa_fail_func(x,y);
176 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
177 #else
178 static inline void ppa_fail(ppa_struct *dev, int error_code)
179 #endif
180 {
181         /* If we fail a device then we trash status / message bytes */
182         if (dev->cur_cmd) {
183                 dev->cur_cmd->result = error_code << 16;
184                 dev->failed = 1;
185         }
186 }
187
188 /*
189  * Wait for the high bit to be set.
190  * 
191  * In principle, this could be tied to an interrupt, but the adapter
192  * doesn't appear to be designed to support interrupts.  We spin on
193  * the 0x80 ready bit. 
194  */
195 static unsigned char ppa_wait(ppa_struct *dev)
196 {
197         int k;
198         unsigned short ppb = dev->base;
199         unsigned char r;
200
201         k = PPA_SPIN_TMO;
202         /* Wait for bit 6 and 7 - PJC */
203         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
204                 udelay(1);
205                 r = r_str(ppb);
206         }
207
208         /*
209          * return some status information.
210          * Semantics: 0xc0 = ZIP wants more data
211          *            0xd0 = ZIP wants to send more data
212          *            0xe0 = ZIP is expecting SCSI command data
213          *            0xf0 = end of transfer, ZIP is sending status
214          */
215         if (k)
216                 return (r & 0xf0);
217
218         /* Counter expired - Time out occurred */
219         ppa_fail(dev, DID_TIME_OUT);
220         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
221         return 0;               /* command timed out */
222 }
223
224 /*
225  * Clear EPP Timeout Bit 
226  */
227 static inline void epp_reset(unsigned short ppb)
228 {
229         int i;
230
231         i = r_str(ppb);
232         w_str(ppb, i);
233         w_str(ppb, i & 0xfe);
234 }
235
236 /* 
237  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
238  */
239 static inline void ecp_sync(ppa_struct *dev)
240 {
241         int i, ppb_hi = dev->dev->port->base_hi;
242
243         if (ppb_hi == 0)
244                 return;
245
246         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
247                 for (i = 0; i < 100; i++) {
248                         if (r_ecr(ppb_hi) & 0x01)
249                                 return;
250                         udelay(5);
251                 }
252                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
253         }
254 }
255
256 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
257 {
258         int i;
259
260         for (i = len; i; i--) {
261                 w_dtr(base, *buffer++);
262                 w_ctr(base, 0xe);
263                 w_ctr(base, 0xc);
264         }
265         return 1;               /* All went well - we hope! */
266 }
267
268 static int ppa_byte_in(unsigned short base, char *buffer, int len)
269 {
270         int i;
271
272         for (i = len; i; i--) {
273                 *buffer++ = r_dtr(base);
274                 w_ctr(base, 0x27);
275                 w_ctr(base, 0x25);
276         }
277         return 1;               /* All went well - we hope! */
278 }
279
280 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
281 {
282         for (; len; len--) {
283                 unsigned char h;
284
285                 w_ctr(base, 0x4);
286                 h = r_str(base) & 0xf0;
287                 w_ctr(base, 0x6);
288                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
289         }
290         return 1;               /* All went well - we hope! */
291 }
292
293 static int ppa_out(ppa_struct *dev, char *buffer, int len)
294 {
295         int r;
296         unsigned short ppb = dev->base;
297
298         r = ppa_wait(dev);
299
300         if ((r & 0x50) != 0x40) {
301                 ppa_fail(dev, DID_ERROR);
302                 return 0;
303         }
304         switch (dev->mode) {
305         case PPA_NIBBLE:
306         case PPA_PS2:
307                 /* 8 bit output, with a loop */
308                 r = ppa_byte_out(ppb, buffer, len);
309                 break;
310
311         case PPA_EPP_32:
312         case PPA_EPP_16:
313         case PPA_EPP_8:
314                 epp_reset(ppb);
315                 w_ctr(ppb, 0x4);
316 #ifdef CONFIG_SCSI_IZIP_EPP16
317                 if (!(((long) buffer | len) & 0x01))
318                         outsw(ppb + 4, buffer, len >> 1);
319 #else
320                 if (!(((long) buffer | len) & 0x03))
321                         outsl(ppb + 4, buffer, len >> 2);
322 #endif
323                 else
324                         outsb(ppb + 4, buffer, len);
325                 w_ctr(ppb, 0xc);
326                 r = !(r_str(ppb) & 0x01);
327                 w_ctr(ppb, 0xc);
328                 ecp_sync(dev);
329                 break;
330
331         default:
332                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
333                 r = 0;
334         }
335         return r;
336 }
337
338 static int ppa_in(ppa_struct *dev, char *buffer, int len)
339 {
340         int r;
341         unsigned short ppb = dev->base;
342
343         r = ppa_wait(dev);
344
345         if ((r & 0x50) != 0x50) {
346                 ppa_fail(dev, DID_ERROR);
347                 return 0;
348         }
349         switch (dev->mode) {
350         case PPA_NIBBLE:
351                 /* 4 bit input, with a loop */
352                 r = ppa_nibble_in(ppb, buffer, len);
353                 w_ctr(ppb, 0xc);
354                 break;
355
356         case PPA_PS2:
357                 /* 8 bit input, with a loop */
358                 w_ctr(ppb, 0x25);
359                 r = ppa_byte_in(ppb, buffer, len);
360                 w_ctr(ppb, 0x4);
361                 w_ctr(ppb, 0xc);
362                 break;
363
364         case PPA_EPP_32:
365         case PPA_EPP_16:
366         case PPA_EPP_8:
367                 epp_reset(ppb);
368                 w_ctr(ppb, 0x24);
369 #ifdef CONFIG_SCSI_IZIP_EPP16
370                 if (!(((long) buffer | len) & 0x01))
371                         insw(ppb + 4, buffer, len >> 1);
372 #else
373                 if (!(((long) buffer | len) & 0x03))
374                         insl(ppb + 4, buffer, len >> 2);
375 #endif
376                 else
377                         insb(ppb + 4, buffer, len);
378                 w_ctr(ppb, 0x2c);
379                 r = !(r_str(ppb) & 0x01);
380                 w_ctr(ppb, 0x2c);
381                 ecp_sync(dev);
382                 break;
383
384         default:
385                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
386                 r = 0;
387                 break;
388         }
389         return r;
390 }
391
392 /* end of ppa_io.h */
393 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
394 {
395         w_dtr(ppb, b);
396         w_ctr(ppb, 0xc);
397         w_ctr(ppb, 0xe);
398         w_ctr(ppb, 0xc);
399         w_ctr(ppb, 0x4);
400         w_ctr(ppb, 0xc);
401 }
402
403 static void ppa_disconnect(ppa_struct *dev)
404 {
405         unsigned short ppb = dev->base;
406
407         ppa_d_pulse(ppb, 0);
408         ppa_d_pulse(ppb, 0x3c);
409         ppa_d_pulse(ppb, 0x20);
410         ppa_d_pulse(ppb, 0xf);
411 }
412
413 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
414 {
415         w_dtr(ppb, b);
416         w_ctr(ppb, 0x4);
417         w_ctr(ppb, 0x6);
418         w_ctr(ppb, 0x4);
419         w_ctr(ppb, 0xc);
420 }
421
422 static inline void ppa_connect(ppa_struct *dev, int flag)
423 {
424         unsigned short ppb = dev->base;
425
426         ppa_c_pulse(ppb, 0);
427         ppa_c_pulse(ppb, 0x3c);
428         ppa_c_pulse(ppb, 0x20);
429         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
430                 ppa_c_pulse(ppb, 0xcf);
431         else
432                 ppa_c_pulse(ppb, 0x8f);
433 }
434
435 static int ppa_select(ppa_struct *dev, int target)
436 {
437         int k;
438         unsigned short ppb = dev->base;
439
440         /*
441          * Bit 6 (0x40) is the device selected bit.
442          * First we must wait till the current device goes off line...
443          */
444         k = PPA_SELECT_TMO;
445         do {
446                 k--;
447                 udelay(1);
448         } while ((r_str(ppb) & 0x40) && (k));
449         if (!k)
450                 return 0;
451
452         w_dtr(ppb, (1 << target));
453         w_ctr(ppb, 0xe);
454         w_ctr(ppb, 0xc);
455         w_dtr(ppb, 0x80);       /* This is NOT the initator */
456         w_ctr(ppb, 0x8);
457
458         k = PPA_SELECT_TMO;
459         do {
460                 k--;
461                 udelay(1);
462         }
463         while (!(r_str(ppb) & 0x40) && (k));
464         if (!k)
465                 return 0;
466
467         return 1;
468 }
469
470 /* 
471  * This is based on a trace of what the Iomega DOS 'guest' driver does.
472  * I've tried several different kinds of parallel ports with guest and
473  * coded this to react in the same ways that it does.
474  * 
475  * The return value from this function is just a hint about where the
476  * handshaking failed.
477  * 
478  */
479 static int ppa_init(ppa_struct *dev)
480 {
481         int retv;
482         unsigned short ppb = dev->base;
483
484         ppa_disconnect(dev);
485         ppa_connect(dev, CONNECT_NORMAL);
486
487         retv = 2;               /* Failed */
488
489         w_ctr(ppb, 0xe);
490         if ((r_str(ppb) & 0x08) == 0x08)
491                 retv--;
492
493         w_ctr(ppb, 0xc);
494         if ((r_str(ppb) & 0x08) == 0x00)
495                 retv--;
496
497         if (!retv)
498                 ppa_reset_pulse(ppb);
499         udelay(1000);           /* Allow devices to settle down */
500         ppa_disconnect(dev);
501         udelay(1000);           /* Another delay to allow devices to settle */
502
503         if (retv)
504                 return -EIO;
505
506         return device_check(dev);
507 }
508
509 static inline int ppa_send_command(struct scsi_cmnd *cmd)
510 {
511         ppa_struct *dev = ppa_dev(cmd->device->host);
512         int k;
513
514         w_ctr(dev->base, 0x0c);
515
516         for (k = 0; k < cmd->cmd_len; k++)
517                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
518                         return 0;
519         return 1;
520 }
521
522 /*
523  * The bulk flag enables some optimisations in the data transfer loops,
524  * it should be true for any command that transfers data in integral
525  * numbers of sectors.
526  * 
527  * The driver appears to remain stable if we speed up the parallel port
528  * i/o in this function, but not elsewhere.
529  */
530 static int ppa_completion(struct scsi_cmnd *cmd)
531 {
532         /* Return codes:
533          * -1     Error
534          *  0     Told to schedule
535          *  1     Finished data transfer
536          */
537         ppa_struct *dev = ppa_dev(cmd->device->host);
538         unsigned short ppb = dev->base;
539         unsigned long start_jiffies = jiffies;
540
541         unsigned char r, v;
542         int fast, bulk, status;
543
544         v = cmd->cmnd[0];
545         bulk = ((v == READ_6) ||
546                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
547
548         /*
549          * We only get here if the drive is ready to comunicate,
550          * hence no need for a full ppa_wait.
551          */
552         r = (r_str(ppb) & 0xf0);
553
554         while (r != (unsigned char) 0xf0) {
555                 /*
556                  * If we have been running for more than a full timer tick
557                  * then take a rest.
558                  */
559                 if (time_after(jiffies, start_jiffies + 1))
560                         return 0;
561
562                 if ((cmd->SCp.this_residual <= 0)) {
563                         ppa_fail(dev, DID_ERROR);
564                         return -1;      /* ERROR_RETURN */
565                 }
566
567                 /* On some hardware we have SCSI disconnected (6th bit low)
568                  * for about 100usecs. It is too expensive to wait a 
569                  * tick on every loop so we busy wait for no more than
570                  * 500usecs to give the drive a chance first. We do not 
571                  * change things for "normal" hardware since generally 
572                  * the 6th bit is always high.
573                  * This makes the CPU load higher on some hardware 
574                  * but otherwise we can not get more than 50K/secs 
575                  * on this problem hardware.
576                  */
577                 if ((r & 0xc0) != 0xc0) {
578                         /* Wait for reconnection should be no more than 
579                          * jiffy/2 = 5ms = 5000 loops
580                          */
581                         unsigned long k = dev->recon_tmo;
582                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
583                              k--)
584                                 udelay(1);
585
586                         if (!k)
587                                 return 0;
588                 }
589
590                 /* determine if we should use burst I/O */
591                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
592                     ? PPA_BURST_SIZE : 1;
593
594                 if (r == (unsigned char) 0xc0)
595                         status = ppa_out(dev, cmd->SCp.ptr, fast);
596                 else
597                         status = ppa_in(dev, cmd->SCp.ptr, fast);
598
599                 cmd->SCp.ptr += fast;
600                 cmd->SCp.this_residual -= fast;
601
602                 if (!status) {
603                         ppa_fail(dev, DID_BUS_BUSY);
604                         return -1;      /* ERROR_RETURN */
605                 }
606                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
607                         /* if scatter/gather, advance to the next segment */
608                         if (cmd->SCp.buffers_residual--) {
609                                 cmd->SCp.buffer++;
610                                 cmd->SCp.this_residual =
611                                     cmd->SCp.buffer->length;
612                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
613                         }
614                 }
615                 /* Now check to see if the drive is ready to comunicate */
616                 r = (r_str(ppb) & 0xf0);
617                 /* If not, drop back down to the scheduler and wait a timer tick */
618                 if (!(r & 0x80))
619                         return 0;
620         }
621         return 1;               /* FINISH_RETURN */
622 }
623
624 /*
625  * Since the PPA itself doesn't generate interrupts, we use
626  * the scheduler's task queue to generate a stream of call-backs and
627  * complete the request when the drive is ready.
628  */
629 static void ppa_interrupt(struct work_struct *work)
630 {
631         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
632         struct scsi_cmnd *cmd = dev->cur_cmd;
633
634         if (!cmd) {
635                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
636                 return;
637         }
638         if (ppa_engine(dev, cmd)) {
639                 schedule_delayed_work(&dev->ppa_tq, 1);
640                 return;
641         }
642         /* Command must of completed hence it is safe to let go... */
643 #if PPA_DEBUG > 0
644         switch ((cmd->result >> 16) & 0xff) {
645         case DID_OK:
646                 break;
647         case DID_NO_CONNECT:
648                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
649                 break;
650         case DID_BUS_BUSY:
651                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
652                 break;
653         case DID_TIME_OUT:
654                 printk(KERN_DEBUG "ppa: unknown timeout\n");
655                 break;
656         case DID_ABORT:
657                 printk(KERN_DEBUG "ppa: told to abort\n");
658                 break;
659         case DID_PARITY:
660                 printk(KERN_DEBUG "ppa: parity error (???)\n");
661                 break;
662         case DID_ERROR:
663                 printk(KERN_DEBUG "ppa: internal driver error\n");
664                 break;
665         case DID_RESET:
666                 printk(KERN_DEBUG "ppa: told to reset device\n");
667                 break;
668         case DID_BAD_INTR:
669                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
670                 break;
671         default:
672                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
673                        (cmd->result >> 16) & 0xff);
674         }
675 #endif
676
677         if (cmd->SCp.phase > 1)
678                 ppa_disconnect(dev);
679
680         ppa_pb_dismiss(dev);
681
682         dev->cur_cmd = NULL;
683
684         cmd->scsi_done(cmd);
685 }
686
687 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
688 {
689         unsigned short ppb = dev->base;
690         unsigned char l = 0, h = 0;
691         int retv;
692
693         /* First check for any errors that may of occurred
694          * Here we check for internal errors
695          */
696         if (dev->failed)
697                 return 0;
698
699         switch (cmd->SCp.phase) {
700         case 0:         /* Phase 0 - Waiting for parport */
701                 if (time_after(jiffies, dev->jstart + HZ)) {
702                         /*
703                          * We waited more than a second
704                          * for parport to call us
705                          */
706                         ppa_fail(dev, DID_BUS_BUSY);
707                         return 0;
708                 }
709                 return 1;       /* wait until ppa_wakeup claims parport */
710         case 1:         /* Phase 1 - Connected */
711                 {               /* Perform a sanity check for cable unplugged */
712                         int retv = 2;   /* Failed */
713
714                         ppa_connect(dev, CONNECT_EPP_MAYBE);
715
716                         w_ctr(ppb, 0xe);
717                         if ((r_str(ppb) & 0x08) == 0x08)
718                                 retv--;
719
720                         w_ctr(ppb, 0xc);
721                         if ((r_str(ppb) & 0x08) == 0x00)
722                                 retv--;
723
724                         if (retv) {
725                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
726                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
727                                         ppa_fail(dev, DID_BUS_BUSY);
728                                         return 0;
729                                 } else {
730                                         ppa_disconnect(dev);
731                                         return 1;       /* Try again in a jiffy */
732                                 }
733                         }
734                         cmd->SCp.phase++;
735                 }
736
737         case 2:         /* Phase 2 - We are now talking to the scsi bus */
738                 if (!ppa_select(dev, scmd_id(cmd))) {
739                         ppa_fail(dev, DID_NO_CONNECT);
740                         return 0;
741                 }
742                 cmd->SCp.phase++;
743
744         case 3:         /* Phase 3 - Ready to accept a command */
745                 w_ctr(ppb, 0x0c);
746                 if (!(r_str(ppb) & 0x80))
747                         return 1;
748
749                 if (!ppa_send_command(cmd))
750                         return 0;
751                 cmd->SCp.phase++;
752
753         case 4:         /* Phase 4 - Setup scatter/gather buffers */
754                 if (scsi_bufflen(cmd)) {
755                         cmd->SCp.buffer = scsi_sglist(cmd);
756                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
757                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
758                 } else {
759                         cmd->SCp.buffer = NULL;
760                         cmd->SCp.this_residual = 0;
761                         cmd->SCp.ptr = NULL;
762                 }
763                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
764                 cmd->SCp.phase++;
765
766         case 5:         /* Phase 5 - Data transfer stage */
767                 w_ctr(ppb, 0x0c);
768                 if (!(r_str(ppb) & 0x80))
769                         return 1;
770
771                 retv = ppa_completion(cmd);
772                 if (retv == -1)
773                         return 0;
774                 if (retv == 0)
775                         return 1;
776                 cmd->SCp.phase++;
777
778         case 6:         /* Phase 6 - Read status/message */
779                 cmd->result = DID_OK << 16;
780                 /* Check for data overrun */
781                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
782                         ppa_fail(dev, DID_ERROR);
783                         return 0;
784                 }
785                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
786                         /* Check for optional message byte */
787                         if (ppa_wait(dev) == (unsigned char) 0xf0)
788                                 ppa_in(dev, &h, 1);
789                         cmd->result =
790                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
791                 }
792                 return 0;       /* Finished */
793                 break;
794
795         default:
796                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
797         }
798         return 0;
799 }
800
801 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
802                 void (*done) (struct scsi_cmnd *))
803 {
804         ppa_struct *dev = ppa_dev(cmd->device->host);
805
806         if (dev->cur_cmd) {
807                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
808                 return 0;
809         }
810         dev->failed = 0;
811         dev->jstart = jiffies;
812         dev->cur_cmd = cmd;
813         cmd->scsi_done = done;
814         cmd->result = DID_ERROR << 16;  /* default return code */
815         cmd->SCp.phase = 0;     /* bus free */
816
817         schedule_delayed_work(&dev->ppa_tq, 0);
818
819         ppa_pb_claim(dev);
820
821         return 0;
822 }
823
824 static DEF_SCSI_QCMD(ppa_queuecommand)
825
826 /*
827  * Apparently the disk->capacity attribute is off by 1 sector 
828  * for all disk drives.  We add the one here, but it should really
829  * be done in sd.c.  Even if it gets fixed there, this will still
830  * work.
831  */
832 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
833               sector_t capacity, int ip[])
834 {
835         ip[0] = 0x40;
836         ip[1] = 0x20;
837         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
838         if (ip[2] > 1024) {
839                 ip[0] = 0xff;
840                 ip[1] = 0x3f;
841                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
842                 if (ip[2] > 1023)
843                         ip[2] = 1023;
844         }
845         return 0;
846 }
847
848 static int ppa_abort(struct scsi_cmnd *cmd)
849 {
850         ppa_struct *dev = ppa_dev(cmd->device->host);
851         /*
852          * There is no method for aborting commands since Iomega
853          * have tied the SCSI_MESSAGE line high in the interface
854          */
855
856         switch (cmd->SCp.phase) {
857         case 0:         /* Do not have access to parport */
858         case 1:         /* Have not connected to interface */
859                 dev->cur_cmd = NULL;    /* Forget the problem */
860                 return SUCCESS;
861                 break;
862         default:                /* SCSI command sent, can not abort */
863                 return FAILED;
864                 break;
865         }
866 }
867
868 static void ppa_reset_pulse(unsigned int base)
869 {
870         w_dtr(base, 0x40);
871         w_ctr(base, 0x8);
872         udelay(30);
873         w_ctr(base, 0xc);
874 }
875
876 static int ppa_reset(struct scsi_cmnd *cmd)
877 {
878         ppa_struct *dev = ppa_dev(cmd->device->host);
879
880         if (cmd->SCp.phase)
881                 ppa_disconnect(dev);
882         dev->cur_cmd = NULL;    /* Forget the problem */
883
884         ppa_connect(dev, CONNECT_NORMAL);
885         ppa_reset_pulse(dev->base);
886         mdelay(1);              /* device settle delay */
887         ppa_disconnect(dev);
888         mdelay(1);              /* device settle delay */
889         return SUCCESS;
890 }
891
892 static int device_check(ppa_struct *dev)
893 {
894         /* This routine looks for a device and then attempts to use EPP
895            to send a command. If all goes as planned then EPP is available. */
896
897         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
898         int loop, old_mode, status, k, ppb = dev->base;
899         unsigned char l;
900
901         old_mode = dev->mode;
902         for (loop = 0; loop < 8; loop++) {
903                 /* Attempt to use EPP for Test Unit Ready */
904                 if ((ppb & 0x0007) == 0x0000)
905                         dev->mode = PPA_EPP_32;
906
907 second_pass:
908                 ppa_connect(dev, CONNECT_EPP_MAYBE);
909                 /* Select SCSI device */
910                 if (!ppa_select(dev, loop)) {
911                         ppa_disconnect(dev);
912                         continue;
913                 }
914                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
915                        loop, PPA_MODE_STRING[dev->mode]);
916
917                 /* Send SCSI command */
918                 status = 1;
919                 w_ctr(ppb, 0x0c);
920                 for (l = 0; (l < 6) && (status); l++)
921                         status = ppa_out(dev, cmd, 1);
922
923                 if (!status) {
924                         ppa_disconnect(dev);
925                         ppa_connect(dev, CONNECT_EPP_MAYBE);
926                         w_dtr(ppb, 0x40);
927                         w_ctr(ppb, 0x08);
928                         udelay(30);
929                         w_ctr(ppb, 0x0c);
930                         udelay(1000);
931                         ppa_disconnect(dev);
932                         udelay(1000);
933                         if (dev->mode == PPA_EPP_32) {
934                                 dev->mode = old_mode;
935                                 goto second_pass;
936                         }
937                         return -EIO;
938                 }
939                 w_ctr(ppb, 0x0c);
940                 k = 1000000;    /* 1 Second */
941                 do {
942                         l = r_str(ppb);
943                         k--;
944                         udelay(1);
945                 } while (!(l & 0x80) && (k));
946
947                 l &= 0xf0;
948
949                 if (l != 0xf0) {
950                         ppa_disconnect(dev);
951                         ppa_connect(dev, CONNECT_EPP_MAYBE);
952                         ppa_reset_pulse(ppb);
953                         udelay(1000);
954                         ppa_disconnect(dev);
955                         udelay(1000);
956                         if (dev->mode == PPA_EPP_32) {
957                                 dev->mode = old_mode;
958                                 goto second_pass;
959                         }
960                         return -EIO;
961                 }
962                 ppa_disconnect(dev);
963                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
964                        loop, PPA_MODE_STRING[dev->mode]);
965                 ppa_connect(dev, CONNECT_EPP_MAYBE);
966                 ppa_reset_pulse(ppb);
967                 udelay(1000);
968                 ppa_disconnect(dev);
969                 udelay(1000);
970                 return 0;
971         }
972         return -ENODEV;
973 }
974
975 static int ppa_adjust_queue(struct scsi_device *device)
976 {
977         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
978         return 0;
979 }
980
981 static struct scsi_host_template ppa_template = {
982         .module                 = THIS_MODULE,
983         .proc_name              = "ppa",
984         .proc_info              = ppa_proc_info,
985         .name                   = "Iomega VPI0 (ppa) interface",
986         .queuecommand           = ppa_queuecommand,
987         .eh_abort_handler       = ppa_abort,
988         .eh_bus_reset_handler   = ppa_reset,
989         .eh_host_reset_handler  = ppa_reset,
990         .bios_param             = ppa_biosparam,
991         .this_id                = -1,
992         .sg_tablesize           = SG_ALL,
993         .cmd_per_lun            = 1,
994         .use_clustering         = ENABLE_CLUSTERING,
995         .can_queue              = 1,
996         .slave_alloc            = ppa_adjust_queue,
997 };
998
999 /***************************************************************************
1000  *                   Parallel port probing routines                        *
1001  ***************************************************************************/
1002
1003 static LIST_HEAD(ppa_hosts);
1004
1005 static int __ppa_attach(struct parport *pb)
1006 {
1007         struct Scsi_Host *host;
1008         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1009         DEFINE_WAIT(wait);
1010         ppa_struct *dev;
1011         int ports;
1012         int modes, ppb, ppb_hi;
1013         int err = -ENOMEM;
1014
1015         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1016         if (!dev)
1017                 return -ENOMEM;
1018         dev->base = -1;
1019         dev->mode = PPA_AUTODETECT;
1020         dev->recon_tmo = PPA_RECON_TMO;
1021         init_waitqueue_head(&waiting);
1022         dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1023                                             NULL, 0, dev);
1024
1025         if (!dev->dev)
1026                 goto out;
1027
1028         /* Claim the bus so it remembers what we do to the control
1029          * registers. [ CTR and ECP ]
1030          */
1031         err = -EBUSY;
1032         dev->waiting = &waiting;
1033         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1034         if (ppa_pb_claim(dev))
1035                 schedule_timeout(3 * HZ);
1036         if (dev->wanted) {
1037                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1038                                 "a pardevice is owning the port for too long "
1039                                 "time!\n", pb->number);
1040                 ppa_pb_dismiss(dev);
1041                 dev->waiting = NULL;
1042                 finish_wait(&waiting, &wait);
1043                 goto out1;
1044         }
1045         dev->waiting = NULL;
1046         finish_wait(&waiting, &wait);
1047         ppb = dev->base = dev->dev->port->base;
1048         ppb_hi = dev->dev->port->base_hi;
1049         w_ctr(ppb, 0x0c);
1050         modes = dev->dev->port->modes;
1051
1052         /* Mode detection works up the chain of speed
1053          * This avoids a nasty if-then-else-if-... tree
1054          */
1055         dev->mode = PPA_NIBBLE;
1056
1057         if (modes & PARPORT_MODE_TRISTATE)
1058                 dev->mode = PPA_PS2;
1059
1060         if (modes & PARPORT_MODE_ECP) {
1061                 w_ecr(ppb_hi, 0x20);
1062                 dev->mode = PPA_PS2;
1063         }
1064         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1065                 w_ecr(ppb_hi, 0x80);
1066
1067         /* Done configuration */
1068
1069         err = ppa_init(dev);
1070         ppa_pb_release(dev);
1071
1072         if (err)
1073                 goto out1;
1074
1075         /* now the glue ... */
1076         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1077                 ports = 3;
1078         else
1079                 ports = 8;
1080
1081         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1082
1083         err = -ENOMEM;
1084         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1085         if (!host)
1086                 goto out1;
1087         host->io_port = pb->base;
1088         host->n_io_port = ports;
1089         host->dma_channel = -1;
1090         host->unique_id = pb->number;
1091         *(ppa_struct **)&host->hostdata = dev;
1092         dev->host = host;
1093         list_add_tail(&dev->list, &ppa_hosts);
1094         err = scsi_add_host(host, NULL);
1095         if (err)
1096                 goto out2;
1097         scsi_scan_host(host);
1098         return 0;
1099 out2:
1100         list_del_init(&dev->list);
1101         scsi_host_put(host);
1102 out1:
1103         parport_unregister_device(dev->dev);
1104 out:
1105         kfree(dev);
1106         return err;
1107 }
1108
1109 static void ppa_attach(struct parport *pb)
1110 {
1111         __ppa_attach(pb);
1112 }
1113
1114 static void ppa_detach(struct parport *pb)
1115 {
1116         ppa_struct *dev;
1117         list_for_each_entry(dev, &ppa_hosts, list) {
1118                 if (dev->dev->port == pb) {
1119                         list_del_init(&dev->list);
1120                         scsi_remove_host(dev->host);
1121                         scsi_host_put(dev->host);
1122                         parport_unregister_device(dev->dev);
1123                         kfree(dev);
1124                         break;
1125                 }
1126         }
1127 }
1128
1129 static struct parport_driver ppa_driver = {
1130         .name   = "ppa",
1131         .attach = ppa_attach,
1132         .detach = ppa_detach,
1133 };
1134
1135 static int __init ppa_driver_init(void)
1136 {
1137         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1138         return parport_register_driver(&ppa_driver);
1139 }
1140
1141 static void __exit ppa_driver_exit(void)
1142 {
1143         parport_unregister_driver(&ppa_driver);
1144 }
1145
1146 module_init(ppa_driver_init);
1147 module_exit(ppa_driver_exit);
1148 MODULE_LICENSE("GPL");