Merge tag 'devfreq-next-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.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         unsigned int dev_no;    /* Device number                */
41         wait_queue_head_t *waiting;
42         struct Scsi_Host *host;
43         struct list_head list;
44 } ppa_struct;
45
46 #include  "ppa.h"
47
48 static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
49 {
50         return *(ppa_struct **)&host->hostdata;
51 }
52
53 static DEFINE_SPINLOCK(arbitration_lock);
54
55 static void got_it(ppa_struct *dev)
56 {
57         dev->base = dev->dev->port->base;
58         if (dev->cur_cmd)
59                 dev->cur_cmd->SCp.phase = 1;
60         else
61                 wake_up(dev->waiting);
62 }
63
64 static void ppa_wakeup(void *ref)
65 {
66         ppa_struct *dev = (ppa_struct *) ref;
67         unsigned long flags;
68
69         spin_lock_irqsave(&arbitration_lock, flags);
70         if (dev->wanted) {
71                 parport_claim(dev->dev);
72                 got_it(dev);
73                 dev->wanted = 0;
74         }
75         spin_unlock_irqrestore(&arbitration_lock, flags);
76         return;
77 }
78
79 static int ppa_pb_claim(ppa_struct *dev)
80 {
81         unsigned long flags;
82         int res = 1;
83         spin_lock_irqsave(&arbitration_lock, flags);
84         if (parport_claim(dev->dev) == 0) {
85                 got_it(dev);
86                 res = 0;
87         }
88         dev->wanted = res;
89         spin_unlock_irqrestore(&arbitration_lock, flags);
90         return res;
91 }
92
93 static void ppa_pb_dismiss(ppa_struct *dev)
94 {
95         unsigned long flags;
96         int wanted;
97         spin_lock_irqsave(&arbitration_lock, flags);
98         wanted = dev->wanted;
99         dev->wanted = 0;
100         spin_unlock_irqrestore(&arbitration_lock, flags);
101         if (!wanted)
102                 parport_release(dev->dev);
103 }
104
105 static inline void ppa_pb_release(ppa_struct *dev)
106 {
107         parport_release(dev->dev);
108 }
109
110 /*
111  * Start of Chipset kludges
112  */
113
114 /* This is to give the ppa driver a way to modify the timings (and other
115  * parameters) by writing to the /proc/scsi/ppa/0 file.
116  * Very simple method really... (To simple, no error checking :( )
117  * Reason: Kernel hackers HATE having to unload and reload modules for
118  * testing...
119  * Also gives a method to use a script to obtain optimum timings (TODO)
120  */
121
122 static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
123 {
124         ppa_struct *dev = ppa_dev(host);
125         unsigned long x;
126
127         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
128                 x = simple_strtoul(buffer + 5, NULL, 0);
129                 dev->mode = x;
130                 return length;
131         }
132         if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
133                 x = simple_strtoul(buffer + 10, NULL, 0);
134                 dev->recon_tmo = x;
135                 printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
136                 return length;
137         }
138         printk(KERN_WARNING "ppa /proc: invalid variable\n");
139         return -EINVAL;
140 }
141
142 static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
143 {
144         ppa_struct *dev = ppa_dev(host);
145
146         seq_printf(m, "Version : %s\n", PPA_VERSION);
147         seq_printf(m, "Parport : %s\n", dev->dev->port->name);
148         seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
149 #if PPA_DEBUG > 0
150         seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
151 #endif
152         return 0;
153 }
154
155 static int device_check(ppa_struct *dev);
156
157 #if PPA_DEBUG > 0
158 #define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
159            y, __func__, __LINE__); ppa_fail_func(x,y);
160 static inline void ppa_fail_func(ppa_struct *dev, int error_code)
161 #else
162 static inline void ppa_fail(ppa_struct *dev, int error_code)
163 #endif
164 {
165         /* If we fail a device then we trash status / message bytes */
166         if (dev->cur_cmd) {
167                 dev->cur_cmd->result = error_code << 16;
168                 dev->failed = 1;
169         }
170 }
171
172 /*
173  * Wait for the high bit to be set.
174  * 
175  * In principle, this could be tied to an interrupt, but the adapter
176  * doesn't appear to be designed to support interrupts.  We spin on
177  * the 0x80 ready bit. 
178  */
179 static unsigned char ppa_wait(ppa_struct *dev)
180 {
181         int k;
182         unsigned short ppb = dev->base;
183         unsigned char r;
184
185         k = PPA_SPIN_TMO;
186         /* Wait for bit 6 and 7 - PJC */
187         for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
188                 udelay(1);
189                 r = r_str(ppb);
190         }
191
192         /*
193          * return some status information.
194          * Semantics: 0xc0 = ZIP wants more data
195          *            0xd0 = ZIP wants to send more data
196          *            0xe0 = ZIP is expecting SCSI command data
197          *            0xf0 = end of transfer, ZIP is sending status
198          */
199         if (k)
200                 return (r & 0xf0);
201
202         /* Counter expired - Time out occurred */
203         ppa_fail(dev, DID_TIME_OUT);
204         printk(KERN_WARNING "ppa timeout in ppa_wait\n");
205         return 0;               /* command timed out */
206 }
207
208 /*
209  * Clear EPP Timeout Bit 
210  */
211 static inline void epp_reset(unsigned short ppb)
212 {
213         int i;
214
215         i = r_str(ppb);
216         w_str(ppb, i);
217         w_str(ppb, i & 0xfe);
218 }
219
220 /* 
221  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
222  */
223 static inline void ecp_sync(ppa_struct *dev)
224 {
225         int i, ppb_hi = dev->dev->port->base_hi;
226
227         if (ppb_hi == 0)
228                 return;
229
230         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
231                 for (i = 0; i < 100; i++) {
232                         if (r_ecr(ppb_hi) & 0x01)
233                                 return;
234                         udelay(5);
235                 }
236                 printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
237         }
238 }
239
240 static int ppa_byte_out(unsigned short base, const char *buffer, int len)
241 {
242         int i;
243
244         for (i = len; i; i--) {
245                 w_dtr(base, *buffer++);
246                 w_ctr(base, 0xe);
247                 w_ctr(base, 0xc);
248         }
249         return 1;               /* All went well - we hope! */
250 }
251
252 static int ppa_byte_in(unsigned short base, char *buffer, int len)
253 {
254         int i;
255
256         for (i = len; i; i--) {
257                 *buffer++ = r_dtr(base);
258                 w_ctr(base, 0x27);
259                 w_ctr(base, 0x25);
260         }
261         return 1;               /* All went well - we hope! */
262 }
263
264 static int ppa_nibble_in(unsigned short base, char *buffer, int len)
265 {
266         for (; len; len--) {
267                 unsigned char h;
268
269                 w_ctr(base, 0x4);
270                 h = r_str(base) & 0xf0;
271                 w_ctr(base, 0x6);
272                 *buffer++ = h | ((r_str(base) & 0xf0) >> 4);
273         }
274         return 1;               /* All went well - we hope! */
275 }
276
277 static int ppa_out(ppa_struct *dev, char *buffer, int len)
278 {
279         int r;
280         unsigned short ppb = dev->base;
281
282         r = ppa_wait(dev);
283
284         if ((r & 0x50) != 0x40) {
285                 ppa_fail(dev, DID_ERROR);
286                 return 0;
287         }
288         switch (dev->mode) {
289         case PPA_NIBBLE:
290         case PPA_PS2:
291                 /* 8 bit output, with a loop */
292                 r = ppa_byte_out(ppb, buffer, len);
293                 break;
294
295         case PPA_EPP_32:
296         case PPA_EPP_16:
297         case PPA_EPP_8:
298                 epp_reset(ppb);
299                 w_ctr(ppb, 0x4);
300 #ifdef CONFIG_SCSI_IZIP_EPP16
301                 if (!(((long) buffer | len) & 0x01))
302                         outsw(ppb + 4, buffer, len >> 1);
303 #else
304                 if (!(((long) buffer | len) & 0x03))
305                         outsl(ppb + 4, buffer, len >> 2);
306 #endif
307                 else
308                         outsb(ppb + 4, buffer, len);
309                 w_ctr(ppb, 0xc);
310                 r = !(r_str(ppb) & 0x01);
311                 w_ctr(ppb, 0xc);
312                 ecp_sync(dev);
313                 break;
314
315         default:
316                 printk(KERN_ERR "PPA: bug in ppa_out()\n");
317                 r = 0;
318         }
319         return r;
320 }
321
322 static int ppa_in(ppa_struct *dev, char *buffer, int len)
323 {
324         int r;
325         unsigned short ppb = dev->base;
326
327         r = ppa_wait(dev);
328
329         if ((r & 0x50) != 0x50) {
330                 ppa_fail(dev, DID_ERROR);
331                 return 0;
332         }
333         switch (dev->mode) {
334         case PPA_NIBBLE:
335                 /* 4 bit input, with a loop */
336                 r = ppa_nibble_in(ppb, buffer, len);
337                 w_ctr(ppb, 0xc);
338                 break;
339
340         case PPA_PS2:
341                 /* 8 bit input, with a loop */
342                 w_ctr(ppb, 0x25);
343                 r = ppa_byte_in(ppb, buffer, len);
344                 w_ctr(ppb, 0x4);
345                 w_ctr(ppb, 0xc);
346                 break;
347
348         case PPA_EPP_32:
349         case PPA_EPP_16:
350         case PPA_EPP_8:
351                 epp_reset(ppb);
352                 w_ctr(ppb, 0x24);
353 #ifdef CONFIG_SCSI_IZIP_EPP16
354                 if (!(((long) buffer | len) & 0x01))
355                         insw(ppb + 4, buffer, len >> 1);
356 #else
357                 if (!(((long) buffer | len) & 0x03))
358                         insl(ppb + 4, buffer, len >> 2);
359 #endif
360                 else
361                         insb(ppb + 4, buffer, len);
362                 w_ctr(ppb, 0x2c);
363                 r = !(r_str(ppb) & 0x01);
364                 w_ctr(ppb, 0x2c);
365                 ecp_sync(dev);
366                 break;
367
368         default:
369                 printk(KERN_ERR "PPA: bug in ppa_ins()\n");
370                 r = 0;
371                 break;
372         }
373         return r;
374 }
375
376 /* end of ppa_io.h */
377 static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
378 {
379         w_dtr(ppb, b);
380         w_ctr(ppb, 0xc);
381         w_ctr(ppb, 0xe);
382         w_ctr(ppb, 0xc);
383         w_ctr(ppb, 0x4);
384         w_ctr(ppb, 0xc);
385 }
386
387 static void ppa_disconnect(ppa_struct *dev)
388 {
389         unsigned short ppb = dev->base;
390
391         ppa_d_pulse(ppb, 0);
392         ppa_d_pulse(ppb, 0x3c);
393         ppa_d_pulse(ppb, 0x20);
394         ppa_d_pulse(ppb, 0xf);
395 }
396
397 static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
398 {
399         w_dtr(ppb, b);
400         w_ctr(ppb, 0x4);
401         w_ctr(ppb, 0x6);
402         w_ctr(ppb, 0x4);
403         w_ctr(ppb, 0xc);
404 }
405
406 static inline void ppa_connect(ppa_struct *dev, int flag)
407 {
408         unsigned short ppb = dev->base;
409
410         ppa_c_pulse(ppb, 0);
411         ppa_c_pulse(ppb, 0x3c);
412         ppa_c_pulse(ppb, 0x20);
413         if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
414                 ppa_c_pulse(ppb, 0xcf);
415         else
416                 ppa_c_pulse(ppb, 0x8f);
417 }
418
419 static int ppa_select(ppa_struct *dev, int target)
420 {
421         int k;
422         unsigned short ppb = dev->base;
423
424         /*
425          * Bit 6 (0x40) is the device selected bit.
426          * First we must wait till the current device goes off line...
427          */
428         k = PPA_SELECT_TMO;
429         do {
430                 k--;
431                 udelay(1);
432         } while ((r_str(ppb) & 0x40) && (k));
433         if (!k)
434                 return 0;
435
436         w_dtr(ppb, (1 << target));
437         w_ctr(ppb, 0xe);
438         w_ctr(ppb, 0xc);
439         w_dtr(ppb, 0x80);       /* This is NOT the initator */
440         w_ctr(ppb, 0x8);
441
442         k = PPA_SELECT_TMO;
443         do {
444                 k--;
445                 udelay(1);
446         }
447         while (!(r_str(ppb) & 0x40) && (k));
448         if (!k)
449                 return 0;
450
451         return 1;
452 }
453
454 /* 
455  * This is based on a trace of what the Iomega DOS 'guest' driver does.
456  * I've tried several different kinds of parallel ports with guest and
457  * coded this to react in the same ways that it does.
458  * 
459  * The return value from this function is just a hint about where the
460  * handshaking failed.
461  * 
462  */
463 static int ppa_init(ppa_struct *dev)
464 {
465         int retv;
466         unsigned short ppb = dev->base;
467
468         ppa_disconnect(dev);
469         ppa_connect(dev, CONNECT_NORMAL);
470
471         retv = 2;               /* Failed */
472
473         w_ctr(ppb, 0xe);
474         if ((r_str(ppb) & 0x08) == 0x08)
475                 retv--;
476
477         w_ctr(ppb, 0xc);
478         if ((r_str(ppb) & 0x08) == 0x00)
479                 retv--;
480
481         if (!retv)
482                 ppa_reset_pulse(ppb);
483         udelay(1000);           /* Allow devices to settle down */
484         ppa_disconnect(dev);
485         udelay(1000);           /* Another delay to allow devices to settle */
486
487         if (retv)
488                 return -EIO;
489
490         return device_check(dev);
491 }
492
493 static inline int ppa_send_command(struct scsi_cmnd *cmd)
494 {
495         ppa_struct *dev = ppa_dev(cmd->device->host);
496         int k;
497
498         w_ctr(dev->base, 0x0c);
499
500         for (k = 0; k < cmd->cmd_len; k++)
501                 if (!ppa_out(dev, &cmd->cmnd[k], 1))
502                         return 0;
503         return 1;
504 }
505
506 /*
507  * The bulk flag enables some optimisations in the data transfer loops,
508  * it should be true for any command that transfers data in integral
509  * numbers of sectors.
510  * 
511  * The driver appears to remain stable if we speed up the parallel port
512  * i/o in this function, but not elsewhere.
513  */
514 static int ppa_completion(struct scsi_cmnd *cmd)
515 {
516         /* Return codes:
517          * -1     Error
518          *  0     Told to schedule
519          *  1     Finished data transfer
520          */
521         ppa_struct *dev = ppa_dev(cmd->device->host);
522         unsigned short ppb = dev->base;
523         unsigned long start_jiffies = jiffies;
524
525         unsigned char r, v;
526         int fast, bulk, status;
527
528         v = cmd->cmnd[0];
529         bulk = ((v == READ_6) ||
530                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
531
532         /*
533          * We only get here if the drive is ready to comunicate,
534          * hence no need for a full ppa_wait.
535          */
536         r = (r_str(ppb) & 0xf0);
537
538         while (r != (unsigned char) 0xf0) {
539                 /*
540                  * If we have been running for more than a full timer tick
541                  * then take a rest.
542                  */
543                 if (time_after(jiffies, start_jiffies + 1))
544                         return 0;
545
546                 if ((cmd->SCp.this_residual <= 0)) {
547                         ppa_fail(dev, DID_ERROR);
548                         return -1;      /* ERROR_RETURN */
549                 }
550
551                 /* On some hardware we have SCSI disconnected (6th bit low)
552                  * for about 100usecs. It is too expensive to wait a 
553                  * tick on every loop so we busy wait for no more than
554                  * 500usecs to give the drive a chance first. We do not 
555                  * change things for "normal" hardware since generally 
556                  * the 6th bit is always high.
557                  * This makes the CPU load higher on some hardware 
558                  * but otherwise we can not get more than 50K/secs 
559                  * on this problem hardware.
560                  */
561                 if ((r & 0xc0) != 0xc0) {
562                         /* Wait for reconnection should be no more than 
563                          * jiffy/2 = 5ms = 5000 loops
564                          */
565                         unsigned long k = dev->recon_tmo;
566                         for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
567                              k--)
568                                 udelay(1);
569
570                         if (!k)
571                                 return 0;
572                 }
573
574                 /* determine if we should use burst I/O */
575                 fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
576                     ? PPA_BURST_SIZE : 1;
577
578                 if (r == (unsigned char) 0xc0)
579                         status = ppa_out(dev, cmd->SCp.ptr, fast);
580                 else
581                         status = ppa_in(dev, cmd->SCp.ptr, fast);
582
583                 cmd->SCp.ptr += fast;
584                 cmd->SCp.this_residual -= fast;
585
586                 if (!status) {
587                         ppa_fail(dev, DID_BUS_BUSY);
588                         return -1;      /* ERROR_RETURN */
589                 }
590                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
591                         /* if scatter/gather, advance to the next segment */
592                         if (cmd->SCp.buffers_residual--) {
593                                 cmd->SCp.buffer = sg_next(cmd->SCp.buffer);
594                                 cmd->SCp.this_residual =
595                                     cmd->SCp.buffer->length;
596                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
597                         }
598                 }
599                 /* Now check to see if the drive is ready to comunicate */
600                 r = (r_str(ppb) & 0xf0);
601                 /* If not, drop back down to the scheduler and wait a timer tick */
602                 if (!(r & 0x80))
603                         return 0;
604         }
605         return 1;               /* FINISH_RETURN */
606 }
607
608 /*
609  * Since the PPA itself doesn't generate interrupts, we use
610  * the scheduler's task queue to generate a stream of call-backs and
611  * complete the request when the drive is ready.
612  */
613 static void ppa_interrupt(struct work_struct *work)
614 {
615         ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
616         struct scsi_cmnd *cmd = dev->cur_cmd;
617
618         if (!cmd) {
619                 printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
620                 return;
621         }
622         if (ppa_engine(dev, cmd)) {
623                 schedule_delayed_work(&dev->ppa_tq, 1);
624                 return;
625         }
626         /* Command must of completed hence it is safe to let go... */
627 #if PPA_DEBUG > 0
628         switch ((cmd->result >> 16) & 0xff) {
629         case DID_OK:
630                 break;
631         case DID_NO_CONNECT:
632                 printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
633                 break;
634         case DID_BUS_BUSY:
635                 printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
636                 break;
637         case DID_TIME_OUT:
638                 printk(KERN_DEBUG "ppa: unknown timeout\n");
639                 break;
640         case DID_ABORT:
641                 printk(KERN_DEBUG "ppa: told to abort\n");
642                 break;
643         case DID_PARITY:
644                 printk(KERN_DEBUG "ppa: parity error (???)\n");
645                 break;
646         case DID_ERROR:
647                 printk(KERN_DEBUG "ppa: internal driver error\n");
648                 break;
649         case DID_RESET:
650                 printk(KERN_DEBUG "ppa: told to reset device\n");
651                 break;
652         case DID_BAD_INTR:
653                 printk(KERN_WARNING "ppa: bad interrupt (???)\n");
654                 break;
655         default:
656                 printk(KERN_WARNING "ppa: bad return code (%02x)\n",
657                        (cmd->result >> 16) & 0xff);
658         }
659 #endif
660
661         if (cmd->SCp.phase > 1)
662                 ppa_disconnect(dev);
663
664         ppa_pb_dismiss(dev);
665
666         dev->cur_cmd = NULL;
667
668         cmd->scsi_done(cmd);
669 }
670
671 static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
672 {
673         unsigned short ppb = dev->base;
674         unsigned char l = 0, h = 0;
675         int retv;
676
677         /* First check for any errors that may of occurred
678          * Here we check for internal errors
679          */
680         if (dev->failed)
681                 return 0;
682
683         switch (cmd->SCp.phase) {
684         case 0:         /* Phase 0 - Waiting for parport */
685                 if (time_after(jiffies, dev->jstart + HZ)) {
686                         /*
687                          * We waited more than a second
688                          * for parport to call us
689                          */
690                         ppa_fail(dev, DID_BUS_BUSY);
691                         return 0;
692                 }
693                 return 1;       /* wait until ppa_wakeup claims parport */
694         case 1:         /* Phase 1 - Connected */
695                 {               /* Perform a sanity check for cable unplugged */
696                         int retv = 2;   /* Failed */
697
698                         ppa_connect(dev, CONNECT_EPP_MAYBE);
699
700                         w_ctr(ppb, 0xe);
701                         if ((r_str(ppb) & 0x08) == 0x08)
702                                 retv--;
703
704                         w_ctr(ppb, 0xc);
705                         if ((r_str(ppb) & 0x08) == 0x00)
706                                 retv--;
707
708                         if (retv) {
709                                 if (time_after(jiffies, dev->jstart + (1 * HZ))) {
710                                         printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
711                                         ppa_fail(dev, DID_BUS_BUSY);
712                                         return 0;
713                                 } else {
714                                         ppa_disconnect(dev);
715                                         return 1;       /* Try again in a jiffy */
716                                 }
717                         }
718                         cmd->SCp.phase++;
719                 }
720                 fallthrough;
721
722         case 2:         /* Phase 2 - We are now talking to the scsi bus */
723                 if (!ppa_select(dev, scmd_id(cmd))) {
724                         ppa_fail(dev, DID_NO_CONNECT);
725                         return 0;
726                 }
727                 cmd->SCp.phase++;
728                 fallthrough;
729
730         case 3:         /* Phase 3 - Ready to accept a command */
731                 w_ctr(ppb, 0x0c);
732                 if (!(r_str(ppb) & 0x80))
733                         return 1;
734
735                 if (!ppa_send_command(cmd))
736                         return 0;
737                 cmd->SCp.phase++;
738                 fallthrough;
739
740         case 4:         /* Phase 4 - Setup scatter/gather buffers */
741                 if (scsi_bufflen(cmd)) {
742                         cmd->SCp.buffer = scsi_sglist(cmd);
743                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
744                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
745                 } else {
746                         cmd->SCp.buffer = NULL;
747                         cmd->SCp.this_residual = 0;
748                         cmd->SCp.ptr = NULL;
749                 }
750                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
751                 cmd->SCp.phase++;
752                 fallthrough;
753
754         case 5:         /* Phase 5 - Data transfer stage */
755                 w_ctr(ppb, 0x0c);
756                 if (!(r_str(ppb) & 0x80))
757                         return 1;
758
759                 retv = ppa_completion(cmd);
760                 if (retv == -1)
761                         return 0;
762                 if (retv == 0)
763                         return 1;
764                 cmd->SCp.phase++;
765                 fallthrough;
766
767         case 6:         /* Phase 6 - Read status/message */
768                 cmd->result = DID_OK << 16;
769                 /* Check for data overrun */
770                 if (ppa_wait(dev) != (unsigned char) 0xf0) {
771                         ppa_fail(dev, DID_ERROR);
772                         return 0;
773                 }
774                 if (ppa_in(dev, &l, 1)) {       /* read status byte */
775                         /* Check for optional message byte */
776                         if (ppa_wait(dev) == (unsigned char) 0xf0)
777                                 ppa_in(dev, &h, 1);
778                         cmd->result =
779                             (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
780                 }
781                 return 0;       /* Finished */
782
783         default:
784                 printk(KERN_ERR "ppa: Invalid scsi phase\n");
785         }
786         return 0;
787 }
788
789 static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
790                 void (*done) (struct scsi_cmnd *))
791 {
792         ppa_struct *dev = ppa_dev(cmd->device->host);
793
794         if (dev->cur_cmd) {
795                 printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
796                 return 0;
797         }
798         dev->failed = 0;
799         dev->jstart = jiffies;
800         dev->cur_cmd = cmd;
801         cmd->scsi_done = done;
802         cmd->result = DID_ERROR << 16;  /* default return code */
803         cmd->SCp.phase = 0;     /* bus free */
804
805         schedule_delayed_work(&dev->ppa_tq, 0);
806
807         ppa_pb_claim(dev);
808
809         return 0;
810 }
811
812 static DEF_SCSI_QCMD(ppa_queuecommand)
813
814 /*
815  * Apparently the disk->capacity attribute is off by 1 sector 
816  * for all disk drives.  We add the one here, but it should really
817  * be done in sd.c.  Even if it gets fixed there, this will still
818  * work.
819  */
820 static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
821               sector_t capacity, int ip[])
822 {
823         ip[0] = 0x40;
824         ip[1] = 0x20;
825         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
826         if (ip[2] > 1024) {
827                 ip[0] = 0xff;
828                 ip[1] = 0x3f;
829                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
830                 if (ip[2] > 1023)
831                         ip[2] = 1023;
832         }
833         return 0;
834 }
835
836 static int ppa_abort(struct scsi_cmnd *cmd)
837 {
838         ppa_struct *dev = ppa_dev(cmd->device->host);
839         /*
840          * There is no method for aborting commands since Iomega
841          * have tied the SCSI_MESSAGE line high in the interface
842          */
843
844         switch (cmd->SCp.phase) {
845         case 0:         /* Do not have access to parport */
846         case 1:         /* Have not connected to interface */
847                 dev->cur_cmd = NULL;    /* Forget the problem */
848                 return SUCCESS;
849         default:                /* SCSI command sent, can not abort */
850                 return FAILED;
851         }
852 }
853
854 static void ppa_reset_pulse(unsigned int base)
855 {
856         w_dtr(base, 0x40);
857         w_ctr(base, 0x8);
858         udelay(30);
859         w_ctr(base, 0xc);
860 }
861
862 static int ppa_reset(struct scsi_cmnd *cmd)
863 {
864         ppa_struct *dev = ppa_dev(cmd->device->host);
865
866         if (cmd->SCp.phase)
867                 ppa_disconnect(dev);
868         dev->cur_cmd = NULL;    /* Forget the problem */
869
870         ppa_connect(dev, CONNECT_NORMAL);
871         ppa_reset_pulse(dev->base);
872         mdelay(1);              /* device settle delay */
873         ppa_disconnect(dev);
874         mdelay(1);              /* device settle delay */
875         return SUCCESS;
876 }
877
878 static int device_check(ppa_struct *dev)
879 {
880         /* This routine looks for a device and then attempts to use EPP
881            to send a command. If all goes as planned then EPP is available. */
882
883         static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
884         int loop, old_mode, status, k, ppb = dev->base;
885         unsigned char l;
886
887         old_mode = dev->mode;
888         for (loop = 0; loop < 8; loop++) {
889                 /* Attempt to use EPP for Test Unit Ready */
890                 if ((ppb & 0x0007) == 0x0000)
891                         dev->mode = PPA_EPP_32;
892
893 second_pass:
894                 ppa_connect(dev, CONNECT_EPP_MAYBE);
895                 /* Select SCSI device */
896                 if (!ppa_select(dev, loop)) {
897                         ppa_disconnect(dev);
898                         continue;
899                 }
900                 printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
901                        loop, PPA_MODE_STRING[dev->mode]);
902
903                 /* Send SCSI command */
904                 status = 1;
905                 w_ctr(ppb, 0x0c);
906                 for (l = 0; (l < 6) && (status); l++)
907                         status = ppa_out(dev, cmd, 1);
908
909                 if (!status) {
910                         ppa_disconnect(dev);
911                         ppa_connect(dev, CONNECT_EPP_MAYBE);
912                         w_dtr(ppb, 0x40);
913                         w_ctr(ppb, 0x08);
914                         udelay(30);
915                         w_ctr(ppb, 0x0c);
916                         udelay(1000);
917                         ppa_disconnect(dev);
918                         udelay(1000);
919                         if (dev->mode == PPA_EPP_32) {
920                                 dev->mode = old_mode;
921                                 goto second_pass;
922                         }
923                         return -EIO;
924                 }
925                 w_ctr(ppb, 0x0c);
926                 k = 1000000;    /* 1 Second */
927                 do {
928                         l = r_str(ppb);
929                         k--;
930                         udelay(1);
931                 } while (!(l & 0x80) && (k));
932
933                 l &= 0xf0;
934
935                 if (l != 0xf0) {
936                         ppa_disconnect(dev);
937                         ppa_connect(dev, CONNECT_EPP_MAYBE);
938                         ppa_reset_pulse(ppb);
939                         udelay(1000);
940                         ppa_disconnect(dev);
941                         udelay(1000);
942                         if (dev->mode == PPA_EPP_32) {
943                                 dev->mode = old_mode;
944                                 goto second_pass;
945                         }
946                         return -EIO;
947                 }
948                 ppa_disconnect(dev);
949                 printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
950                        loop, PPA_MODE_STRING[dev->mode]);
951                 ppa_connect(dev, CONNECT_EPP_MAYBE);
952                 ppa_reset_pulse(ppb);
953                 udelay(1000);
954                 ppa_disconnect(dev);
955                 udelay(1000);
956                 return 0;
957         }
958         return -ENODEV;
959 }
960
961 static int ppa_adjust_queue(struct scsi_device *device)
962 {
963         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
964         return 0;
965 }
966
967 static struct scsi_host_template ppa_template = {
968         .module                 = THIS_MODULE,
969         .proc_name              = "ppa",
970         .show_info              = ppa_show_info,
971         .write_info             = ppa_write_info,
972         .name                   = "Iomega VPI0 (ppa) interface",
973         .queuecommand           = ppa_queuecommand,
974         .eh_abort_handler       = ppa_abort,
975         .eh_host_reset_handler  = ppa_reset,
976         .bios_param             = ppa_biosparam,
977         .this_id                = -1,
978         .sg_tablesize           = SG_ALL,
979         .can_queue              = 1,
980         .slave_alloc            = ppa_adjust_queue,
981 };
982
983 /***************************************************************************
984  *                   Parallel port probing routines                        *
985  ***************************************************************************/
986
987 static LIST_HEAD(ppa_hosts);
988
989 /*
990  * Finds the first available device number that can be alloted to the
991  * new ppa device and returns the address of the previous node so that
992  * we can add to the tail and have a list in the ascending order.
993  */
994
995 static inline ppa_struct *find_parent(void)
996 {
997         ppa_struct *dev, *par = NULL;
998         unsigned int cnt = 0;
999
1000         if (list_empty(&ppa_hosts))
1001                 return NULL;
1002
1003         list_for_each_entry(dev, &ppa_hosts, list) {
1004                 if (dev->dev_no != cnt)
1005                         return par;
1006                 cnt++;
1007                 par = dev;
1008         }
1009
1010         return par;
1011 }
1012
1013 static int __ppa_attach(struct parport *pb)
1014 {
1015         struct Scsi_Host *host;
1016         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1017         DEFINE_WAIT(wait);
1018         ppa_struct *dev, *temp;
1019         int ports;
1020         int modes, ppb, ppb_hi;
1021         int err = -ENOMEM;
1022         struct pardev_cb ppa_cb;
1023
1024         dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1025         if (!dev)
1026                 return -ENOMEM;
1027         dev->base = -1;
1028         dev->mode = PPA_AUTODETECT;
1029         dev->recon_tmo = PPA_RECON_TMO;
1030         init_waitqueue_head(&waiting);
1031         temp = find_parent();
1032         if (temp)
1033                 dev->dev_no = temp->dev_no + 1;
1034
1035         memset(&ppa_cb, 0, sizeof(ppa_cb));
1036         ppa_cb.private = dev;
1037         ppa_cb.wakeup = ppa_wakeup;
1038
1039         dev->dev = parport_register_dev_model(pb, "ppa", &ppa_cb, dev->dev_no);
1040
1041         if (!dev->dev)
1042                 goto out;
1043
1044         /* Claim the bus so it remembers what we do to the control
1045          * registers. [ CTR and ECP ]
1046          */
1047         err = -EBUSY;
1048         dev->waiting = &waiting;
1049         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1050         if (ppa_pb_claim(dev))
1051                 schedule_timeout(3 * HZ);
1052         if (dev->wanted) {
1053                 printk(KERN_ERR "ppa%d: failed to claim parport because "
1054                                 "a pardevice is owning the port for too long "
1055                                 "time!\n", pb->number);
1056                 ppa_pb_dismiss(dev);
1057                 dev->waiting = NULL;
1058                 finish_wait(&waiting, &wait);
1059                 goto out1;
1060         }
1061         dev->waiting = NULL;
1062         finish_wait(&waiting, &wait);
1063         ppb = dev->base = dev->dev->port->base;
1064         ppb_hi = dev->dev->port->base_hi;
1065         w_ctr(ppb, 0x0c);
1066         modes = dev->dev->port->modes;
1067
1068         /* Mode detection works up the chain of speed
1069          * This avoids a nasty if-then-else-if-... tree
1070          */
1071         dev->mode = PPA_NIBBLE;
1072
1073         if (modes & PARPORT_MODE_TRISTATE)
1074                 dev->mode = PPA_PS2;
1075
1076         if (modes & PARPORT_MODE_ECP) {
1077                 w_ecr(ppb_hi, 0x20);
1078                 dev->mode = PPA_PS2;
1079         }
1080         if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1081                 w_ecr(ppb_hi, 0x80);
1082
1083         /* Done configuration */
1084
1085         err = ppa_init(dev);
1086         ppa_pb_release(dev);
1087
1088         if (err)
1089                 goto out1;
1090
1091         /* now the glue ... */
1092         if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1093                 ports = 3;
1094         else
1095                 ports = 8;
1096
1097         INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1098
1099         err = -ENOMEM;
1100         host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1101         if (!host)
1102                 goto out1;
1103         host->io_port = pb->base;
1104         host->n_io_port = ports;
1105         host->dma_channel = -1;
1106         host->unique_id = pb->number;
1107         *(ppa_struct **)&host->hostdata = dev;
1108         dev->host = host;
1109         list_add_tail(&dev->list, &ppa_hosts);
1110         err = scsi_add_host(host, NULL);
1111         if (err)
1112                 goto out2;
1113         scsi_scan_host(host);
1114         return 0;
1115 out2:
1116         list_del_init(&dev->list);
1117         scsi_host_put(host);
1118 out1:
1119         parport_unregister_device(dev->dev);
1120 out:
1121         kfree(dev);
1122         return err;
1123 }
1124
1125 static void ppa_attach(struct parport *pb)
1126 {
1127         __ppa_attach(pb);
1128 }
1129
1130 static void ppa_detach(struct parport *pb)
1131 {
1132         ppa_struct *dev;
1133         list_for_each_entry(dev, &ppa_hosts, list) {
1134                 if (dev->dev->port == pb) {
1135                         list_del_init(&dev->list);
1136                         scsi_remove_host(dev->host);
1137                         scsi_host_put(dev->host);
1138                         parport_unregister_device(dev->dev);
1139                         kfree(dev);
1140                         break;
1141                 }
1142         }
1143 }
1144
1145 static struct parport_driver ppa_driver = {
1146         .name           = "ppa",
1147         .match_port     = ppa_attach,
1148         .detach         = ppa_detach,
1149         .devmodel       = true,
1150 };
1151
1152 static int __init ppa_driver_init(void)
1153 {
1154         printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1155         return parport_register_driver(&ppa_driver);
1156 }
1157
1158 static void __exit ppa_driver_exit(void)
1159 {
1160         parport_unregister_driver(&ppa_driver);
1161 }
1162
1163 module_init(ppa_driver_init);
1164 module_exit(ppa_driver_exit);
1165 MODULE_LICENSE("GPL");