1 // SPDX-License-Identifier: GPL-2.0-only
2 /* imm.c -- low level driver for the IOMEGA MatchMaker
3 * parallel port SCSI host adapter.
4 *
5 * (The IMM is the embedded controller in the ZIP Plus drive.)
6 *
7 * My unofficial company acronym list is 21 pages long:
8 * FLA: Four letter acronym with built in facility for
9 * future expansion to five letters.
10 */
11
12 #include <linux/init.h>
13 #include <linux/kernel.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/slab.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 /* The following #define is to avoid a clash with hosts.c */
28 #define IMM_PROBE_SPP 0x0001
29 #define IMM_PROBE_PS2 0x0002
30 #define IMM_PROBE_ECR 0x0010
31 #define IMM_PROBE_EPP17 0x0100
32 #define IMM_PROBE_EPP19 0x0200
33
34
35 typedef struct {
36 struct pardevice *dev; /* Parport device entry */
37 int base; /* Actual port address */
38 int base_hi; /* Hi Base address for ECP-ISA chipset */
39 int mode; /* Transfer mode */
40 struct scsi_cmnd *cur_cmd; /* Current queued command */
41 struct delayed_work imm_tq; /* Polling interrupt stuff */
42 unsigned long jstart; /* Jiffies at start */
43 unsigned failed:1; /* Failure flag */
44 unsigned dp:1; /* Data phase present */
45 unsigned rd:1; /* Read data in data phase */
46 unsigned wanted:1; /* Parport sharing busy flag */
47 unsigned int dev_no; /* Device number */
48 wait_queue_head_t *waiting;
49 struct Scsi_Host *host;
50 struct list_head list;
51 } imm_struct;
52
53 static void imm_reset_pulse(unsigned int base);
54 static int device_check(imm_struct *dev);
55
56 #include "imm.h"
57
imm_dev(struct Scsi_Host * host)58 static inline imm_struct *imm_dev(struct Scsi_Host *host)
59 {
60 return *(imm_struct **)&host->hostdata;
61 }
62
63 static DEFINE_SPINLOCK(arbitration_lock);
64
got_it(imm_struct * dev)65 static void got_it(imm_struct *dev)
66 {
67 dev->base = dev->dev->port->base;
68 if (dev->cur_cmd)
69 imm_scsi_pointer(dev->cur_cmd)->phase = 1;
70 else
71 wake_up(dev->waiting);
72 }
73
imm_wakeup(void * ref)74 static void imm_wakeup(void *ref)
75 {
76 imm_struct *dev = (imm_struct *) ref;
77 unsigned long flags;
78
79 spin_lock_irqsave(&arbitration_lock, flags);
80 if (dev->wanted) {
81 if (parport_claim(dev->dev) == 0) {
82 got_it(dev);
83 dev->wanted = 0;
84 }
85 }
86 spin_unlock_irqrestore(&arbitration_lock, flags);
87 }
88
imm_pb_claim(imm_struct * dev)89 static int imm_pb_claim(imm_struct *dev)
90 {
91 unsigned long flags;
92 int res = 1;
93 spin_lock_irqsave(&arbitration_lock, flags);
94 if (parport_claim(dev->dev) == 0) {
95 got_it(dev);
96 res = 0;
97 }
98 dev->wanted = res;
99 spin_unlock_irqrestore(&arbitration_lock, flags);
100 return res;
101 }
102
imm_pb_dismiss(imm_struct * dev)103 static void imm_pb_dismiss(imm_struct *dev)
104 {
105 unsigned long flags;
106 int wanted;
107 spin_lock_irqsave(&arbitration_lock, flags);
108 wanted = dev->wanted;
109 dev->wanted = 0;
110 spin_unlock_irqrestore(&arbitration_lock, flags);
111 if (!wanted)
112 parport_release(dev->dev);
113 }
114
imm_pb_release(imm_struct * dev)115 static inline void imm_pb_release(imm_struct *dev)
116 {
117 parport_release(dev->dev);
118 }
119
120 /* This is to give the imm driver a way to modify the timings (and other
121 * parameters) by writing to the /proc/scsi/imm/0 file.
122 * Very simple method really... (Too simple, no error checking :( )
123 * Reason: Kernel hackers HATE having to unload and reload modules for
124 * testing...
125 * Also gives a method to use a script to obtain optimum timings (TODO)
126 */
imm_write_info(struct Scsi_Host * host,char * buffer,int length)127 static int imm_write_info(struct Scsi_Host *host, char *buffer, int length)
128 {
129 imm_struct *dev = imm_dev(host);
130
131 if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
132 dev->mode = simple_strtoul(buffer + 5, NULL, 0);
133 return length;
134 }
135 printk("imm /proc: invalid variable\n");
136 return -EINVAL;
137 }
138
imm_show_info(struct seq_file * m,struct Scsi_Host * host)139 static int imm_show_info(struct seq_file *m, struct Scsi_Host *host)
140 {
141 imm_struct *dev = imm_dev(host);
142
143 seq_printf(m, "Version : %s\n", IMM_VERSION);
144 seq_printf(m, "Parport : %s\n", dev->dev->port->name);
145 seq_printf(m, "Mode : %s\n", IMM_MODE_STRING[dev->mode]);
146 return 0;
147 }
148
149 #if IMM_DEBUG > 0
150 #define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\
151 y, __func__, __LINE__); imm_fail_func(x,y);
152 static inline void
imm_fail_func(imm_struct * dev,int error_code)153 imm_fail_func(imm_struct *dev, int error_code)
154 #else
155 static inline void
156 imm_fail(imm_struct *dev, int error_code)
157 #endif
158 {
159 /* If we fail a device then we trash status / message bytes */
160 if (dev->cur_cmd) {
161 dev->cur_cmd->result = error_code << 16;
162 dev->failed = 1;
163 }
164 }
165
166 /*
167 * Wait for the high bit to be set.
168 *
169 * In principle, this could be tied to an interrupt, but the adapter
170 * doesn't appear to be designed to support interrupts. We spin on
171 * the 0x80 ready bit.
172 */
imm_wait(imm_struct * dev)173 static unsigned char imm_wait(imm_struct *dev)
174 {
175 int k;
176 unsigned short ppb = dev->base;
177 unsigned char r;
178
179 w_ctr(ppb, 0x0c);
180
181 k = IMM_SPIN_TMO;
182 do {
183 r = r_str(ppb);
184 k--;
185 udelay(1);
186 }
187 while (!(r & 0x80) && (k));
188
189 /*
190 * STR register (LPT base+1) to SCSI mapping:
191 *
192 * STR imm imm
193 * ===================================
194 * 0x80 S_REQ S_REQ
195 * 0x40 !S_BSY (????)
196 * 0x20 !S_CD !S_CD
197 * 0x10 !S_IO !S_IO
198 * 0x08 (????) !S_BSY
199 *
200 * imm imm meaning
201 * ==================================
202 * 0xf0 0xb8 Bit mask
203 * 0xc0 0x88 ZIP wants more data
204 * 0xd0 0x98 ZIP wants to send more data
205 * 0xe0 0xa8 ZIP is expecting SCSI command data
206 * 0xf0 0xb8 end of transfer, ZIP is sending status
207 */
208 w_ctr(ppb, 0x04);
209 if (k)
210 return (r & 0xb8);
211
212 /* Counter expired - Time out occurred */
213 imm_fail(dev, DID_TIME_OUT);
214 printk("imm timeout in imm_wait\n");
215 return 0; /* command timed out */
216 }
217
imm_negotiate(imm_struct * tmp)218 static int imm_negotiate(imm_struct * tmp)
219 {
220 /*
221 * The following is supposedly the IEEE 1284-1994 negotiate
222 * sequence. I have yet to obtain a copy of the above standard
223 * so this is a bit of a guess...
224 *
225 * A fair chunk of this is based on the Linux parport implementation
226 * of IEEE 1284.
227 *
228 * Return 0 if data available
229 * 1 if no data available
230 */
231
232 unsigned short base = tmp->base;
233 unsigned char a, mode;
234
235 switch (tmp->mode) {
236 case IMM_NIBBLE:
237 mode = 0x00;
238 break;
239 case IMM_PS2:
240 mode = 0x01;
241 break;
242 default:
243 return 0;
244 }
245
246 w_ctr(base, 0x04);
247 udelay(5);
248 w_dtr(base, mode);
249 udelay(100);
250 w_ctr(base, 0x06);
251 udelay(5);
252 a = (r_str(base) & 0x20) ? 0 : 1;
253 udelay(5);
254 w_ctr(base, 0x07);
255 udelay(5);
256 w_ctr(base, 0x06);
257
258 if (a) {
259 printk
260 ("IMM: IEEE1284 negotiate indicates no data available.\n");
261 imm_fail(tmp, DID_ERROR);
262 }
263 return a;
264 }
265
266 /*
267 * Clear EPP timeout bit.
268 */
epp_reset(unsigned short ppb)269 static inline void epp_reset(unsigned short ppb)
270 {
271 int i;
272
273 i = r_str(ppb);
274 w_str(ppb, i);
275 w_str(ppb, i & 0xfe);
276 }
277
278 /*
279 * Wait for empty ECP fifo (if we are in ECP fifo mode only)
280 */
ecp_sync(imm_struct * dev)281 static inline void ecp_sync(imm_struct *dev)
282 {
283 int i, ppb_hi = dev->base_hi;
284
285 if (ppb_hi == 0)
286 return;
287
288 if ((r_ecr(ppb_hi) & 0xe0) == 0x60) { /* mode 011 == ECP fifo mode */
289 for (i = 0; i < 100; i++) {
290 if (r_ecr(ppb_hi) & 0x01)
291 return;
292 udelay(5);
293 }
294 printk("imm: ECP sync failed as data still present in FIFO.\n");
295 }
296 }
297
imm_byte_out(unsigned short base,const char * buffer,int len)298 static int imm_byte_out(unsigned short base, const char *buffer, int len)
299 {
300 int i;
301
302 w_ctr(base, 0x4); /* apparently a sane mode */
303 for (i = len >> 1; i; i--) {
304 w_dtr(base, *buffer++);
305 w_ctr(base, 0x5); /* Drop STROBE low */
306 w_dtr(base, *buffer++);
307 w_ctr(base, 0x0); /* STROBE high + INIT low */
308 }
309 w_ctr(base, 0x4); /* apparently a sane mode */
310 return 1; /* All went well - we hope! */
311 }
312
imm_nibble_in(unsigned short base,char * buffer,int len)313 static int imm_nibble_in(unsigned short base, char *buffer, int len)
314 {
315 unsigned char l;
316 int i;
317
318 /*
319 * The following is based on documented timing signals
320 */
321 w_ctr(base, 0x4);
322 for (i = len; i; i--) {
323 w_ctr(base, 0x6);
324 l = (r_str(base) & 0xf0) >> 4;
325 w_ctr(base, 0x5);
326 *buffer++ = (r_str(base) & 0xf0) | l;
327 w_ctr(base, 0x4);
328 }
329 return 1; /* All went well - we hope! */
330 }
331
imm_byte_in(unsigned short base,char * buffer,int len)332 static int imm_byte_in(unsigned short base, char *buffer, int len)
333 {
334 int i;
335
336 /*
337 * The following is based on documented timing signals
338 */
339 w_ctr(base, 0x4);
340 for (i = len; i; i--) {
341 w_ctr(base, 0x26);
342 *buffer++ = r_dtr(base);
343 w_ctr(base, 0x25);
344 }
345 return 1; /* All went well - we hope! */
346 }
347
imm_out(imm_struct * dev,char * buffer,int len)348 static int imm_out(imm_struct *dev, char *buffer, int len)
349 {
350 unsigned short ppb = dev->base;
351 int r = imm_wait(dev);
352
353 /*
354 * Make sure that:
355 * a) the SCSI bus is BUSY (device still listening)
356 * b) the device is listening
357 */
358 if ((r & 0x18) != 0x08) {
359 imm_fail(dev, DID_ERROR);
360 printk("IMM: returned SCSI status %2x\n", r);
361 return 0;
362 }
363 switch (dev->mode) {
364 case IMM_EPP_32:
365 case IMM_EPP_16:
366 case IMM_EPP_8:
367 epp_reset(ppb);
368 w_ctr(ppb, 0x4);
369 #ifdef CONFIG_SCSI_IZIP_EPP16
370 if (!(((long) buffer | len) & 0x01))
371 outsw(ppb + 4, buffer, len >> 1);
372 #else
373 if (!(((long) buffer | len) & 0x03))
374 outsl(ppb + 4, buffer, len >> 2);
375 #endif
376 else
377 outsb(ppb + 4, buffer, len);
378 w_ctr(ppb, 0xc);
379 r = !(r_str(ppb) & 0x01);
380 w_ctr(ppb, 0xc);
381 ecp_sync(dev);
382 break;
383
384 case IMM_NIBBLE:
385 case IMM_PS2:
386 /* 8 bit output, with a loop */
387 r = imm_byte_out(ppb, buffer, len);
388 break;
389
390 default:
391 printk("IMM: bug in imm_out()\n");
392 r = 0;
393 }
394 return r;
395 }
396
imm_in(imm_struct * dev,char * buffer,int len)397 static int imm_in(imm_struct *dev, char *buffer, int len)
398 {
399 unsigned short ppb = dev->base;
400 int r = imm_wait(dev);
401
402 /*
403 * Make sure that:
404 * a) the SCSI bus is BUSY (device still listening)
405 * b) the device is sending data
406 */
407 if ((r & 0x18) != 0x18) {
408 imm_fail(dev, DID_ERROR);
409 return 0;
410 }
411 switch (dev->mode) {
412 case IMM_NIBBLE:
413 /* 4 bit input, with a loop */
414 r = imm_nibble_in(ppb, buffer, len);
415 w_ctr(ppb, 0xc);
416 break;
417
418 case IMM_PS2:
419 /* 8 bit input, with a loop */
420 r = imm_byte_in(ppb, buffer, len);
421 w_ctr(ppb, 0xc);
422 break;
423
424 case IMM_EPP_32:
425 case IMM_EPP_16:
426 case IMM_EPP_8:
427 epp_reset(ppb);
428 w_ctr(ppb, 0x24);
429 #ifdef CONFIG_SCSI_IZIP_EPP16
430 if (!(((long) buffer | len) & 0x01))
431 insw(ppb + 4, buffer, len >> 1);
432 #else
433 if (!(((long) buffer | len) & 0x03))
434 insl(ppb + 4, buffer, len >> 2);
435 #endif
436 else
437 insb(ppb + 4, buffer, len);
438 w_ctr(ppb, 0x2c);
439 r = !(r_str(ppb) & 0x01);
440 w_ctr(ppb, 0x2c);
441 ecp_sync(dev);
442 break;
443
444 default:
445 printk("IMM: bug in imm_ins()\n");
446 r = 0;
447 break;
448 }
449 return r;
450 }
451
imm_cpp(unsigned short ppb,unsigned char b)452 static int imm_cpp(unsigned short ppb, unsigned char b)
453 {
454 /*
455 * Comments on udelay values refer to the
456 * Command Packet Protocol (CPP) timing diagram.
457 */
458
459 unsigned char s1, s2, s3;
460 w_ctr(ppb, 0x0c);
461 udelay(2); /* 1 usec - infinite */
462 w_dtr(ppb, 0xaa);
463 udelay(10); /* 7 usec - infinite */
464 w_dtr(ppb, 0x55);
465 udelay(10); /* 7 usec - infinite */
466 w_dtr(ppb, 0x00);
467 udelay(10); /* 7 usec - infinite */
468 w_dtr(ppb, 0xff);
469 udelay(10); /* 7 usec - infinite */
470 s1 = r_str(ppb) & 0xb8;
471 w_dtr(ppb, 0x87);
472 udelay(10); /* 7 usec - infinite */
473 s2 = r_str(ppb) & 0xb8;
474 w_dtr(ppb, 0x78);
475 udelay(10); /* 7 usec - infinite */
476 s3 = r_str(ppb) & 0x38;
477 /*
478 * Values for b are:
479 * 0000 00aa Assign address aa to current device
480 * 0010 00aa Select device aa in EPP Winbond mode
481 * 0010 10aa Select device aa in EPP mode
482 * 0011 xxxx Deselect all devices
483 * 0110 00aa Test device aa
484 * 1101 00aa Select device aa in ECP mode
485 * 1110 00aa Select device aa in Compatible mode
486 */
487 w_dtr(ppb, b);
488 udelay(2); /* 1 usec - infinite */
489 w_ctr(ppb, 0x0c);
490 udelay(10); /* 7 usec - infinite */
491 w_ctr(ppb, 0x0d);
492 udelay(2); /* 1 usec - infinite */
493 w_ctr(ppb, 0x0c);
494 udelay(10); /* 7 usec - infinite */
495 w_dtr(ppb, 0xff);
496 udelay(10); /* 7 usec - infinite */
497
498 /*
499 * The following table is electrical pin values.
500 * (BSY is inverted at the CTR register)
501 *
502 * BSY ACK POut SEL Fault
503 * S1 0 X 1 1 1
504 * S2 1 X 0 1 1
505 * S3 L X 1 1 S
506 *
507 * L => Last device in chain
508 * S => Selected
509 *
510 * Observered values for S1,S2,S3 are:
511 * Disconnect => f8/58/78
512 * Connect => f8/58/70
513 */
514 if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))
515 return 1; /* Connected */
516 if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))
517 return 0; /* Disconnected */
518
519 return -1; /* No device present */
520 }
521
imm_connect(imm_struct * dev,int flag)522 static inline int imm_connect(imm_struct *dev, int flag)
523 {
524 unsigned short ppb = dev->base;
525
526 imm_cpp(ppb, 0xe0); /* Select device 0 in compatible mode */
527 imm_cpp(ppb, 0x30); /* Disconnect all devices */
528
529 if ((dev->mode == IMM_EPP_8) ||
530 (dev->mode == IMM_EPP_16) ||
531 (dev->mode == IMM_EPP_32))
532 return imm_cpp(ppb, 0x28); /* Select device 0 in EPP mode */
533 return imm_cpp(ppb, 0xe0); /* Select device 0 in compatible mode */
534 }
535
imm_disconnect(imm_struct * dev)536 static void imm_disconnect(imm_struct *dev)
537 {
538 imm_cpp(dev->base, 0x30); /* Disconnect all devices */
539 }
540
imm_select(imm_struct * dev,int target)541 static int imm_select(imm_struct *dev, int target)
542 {
543 int k;
544 unsigned short ppb = dev->base;
545
546 /*
547 * Firstly we want to make sure there is nothing
548 * holding onto the SCSI bus.
549 */
550 w_ctr(ppb, 0xc);
551
552 k = IMM_SELECT_TMO;
553 do {
554 k--;
555 } while ((r_str(ppb) & 0x08) && (k));
556
557 if (!k)
558 return 0;
559
560 /*
561 * Now assert the SCSI ID (HOST and TARGET) on the data bus
562 */
563 w_ctr(ppb, 0x4);
564 w_dtr(ppb, 0x80 | (1 << target));
565 udelay(1);
566
567 /*
568 * Deassert SELIN first followed by STROBE
569 */
570 w_ctr(ppb, 0xc);
571 w_ctr(ppb, 0xd);
572
573 /*
574 * ACK should drop low while SELIN is deasserted.
575 * FAULT should drop low when the SCSI device latches the bus.
576 */
577 k = IMM_SELECT_TMO;
578 do {
579 k--;
580 }
581 while (!(r_str(ppb) & 0x08) && (k));
582
583 /*
584 * Place the interface back into a sane state (status mode)
585 */
586 w_ctr(ppb, 0xc);
587 return (k) ? 1 : 0;
588 }
589
imm_init(imm_struct * dev)590 static int imm_init(imm_struct *dev)
591 {
592 if (imm_connect(dev, 0) != 1)
593 return -EIO;
594 imm_reset_pulse(dev->base);
595 mdelay(1); /* Delay to allow devices to settle */
596 imm_disconnect(dev);
597 mdelay(1); /* Another delay to allow devices to settle */
598 return device_check(dev);
599 }
600
imm_send_command(struct scsi_cmnd * cmd)601 static inline int imm_send_command(struct scsi_cmnd *cmd)
602 {
603 imm_struct *dev = imm_dev(cmd->device->host);
604 int k;
605
606 /* NOTE: IMM uses byte pairs */
607 for (k = 0; k < cmd->cmd_len; k += 2)
608 if (!imm_out(dev, &cmd->cmnd[k], 2))
609 return 0;
610 return 1;
611 }
612
613 /*
614 * The bulk flag enables some optimisations in the data transfer loops,
615 * it should be true for any command that transfers data in integral
616 * numbers of sectors.
617 *
618 * The driver appears to remain stable if we speed up the parallel port
619 * i/o in this function, but not elsewhere.
620 */
imm_completion(struct scsi_cmnd * const cmd)621 static int imm_completion(struct scsi_cmnd *const cmd)
622 {
623 /* Return codes:
624 * -1 Error
625 * 0 Told to schedule
626 * 1 Finished data transfer
627 */
628 struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);
629 imm_struct *dev = imm_dev(cmd->device->host);
630 unsigned short ppb = dev->base;
631 unsigned long start_jiffies = jiffies;
632
633 unsigned char r, v;
634 int fast, bulk, status;
635
636 v = cmd->cmnd[0];
637 bulk = ((v == READ_6) ||
638 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
639
640 /*
641 * We only get here if the drive is ready to comunicate,
642 * hence no need for a full imm_wait.
643 */
644 w_ctr(ppb, 0x0c);
645 r = (r_str(ppb) & 0xb8);
646
647 /*
648 * while (device is not ready to send status byte)
649 * loop;
650 */
651 while (r != (unsigned char) 0xb8) {
652 /*
653 * If we have been running for more than a full timer tick
654 * then take a rest.
655 */
656 if (time_after(jiffies, start_jiffies + 1))
657 return 0;
658
659 /*
660 * FAIL if:
661 * a) Drive status is screwy (!ready && !present)
662 * b) Drive is requesting/sending more data than expected
663 */
664 if ((r & 0x88) != 0x88 || scsi_pointer->this_residual <= 0) {
665 imm_fail(dev, DID_ERROR);
666 return -1; /* ERROR_RETURN */
667 }
668 /* determine if we should use burst I/O */
669 if (dev->rd == 0) {
670 fast = bulk && scsi_pointer->this_residual >=
671 IMM_BURST_SIZE ? IMM_BURST_SIZE : 2;
672 status = imm_out(dev, scsi_pointer->ptr, fast);
673 } else {
674 fast = bulk && scsi_pointer->this_residual >=
675 IMM_BURST_SIZE ? IMM_BURST_SIZE : 1;
676 status = imm_in(dev, scsi_pointer->ptr, fast);
677 }
678
679 scsi_pointer->ptr += fast;
680 scsi_pointer->this_residual -= fast;
681
682 if (!status) {
683 imm_fail(dev, DID_BUS_BUSY);
684 return -1; /* ERROR_RETURN */
685 }
686 if (scsi_pointer->buffer && !scsi_pointer->this_residual) {
687 /* if scatter/gather, advance to the next segment */
688 if (scsi_pointer->buffers_residual--) {
689 scsi_pointer->buffer =
690 sg_next(scsi_pointer->buffer);
691 scsi_pointer->this_residual =
692 scsi_pointer->buffer->length;
693 scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
694
695 /*
696 * Make sure that we transfer even number of bytes
697 * otherwise it makes imm_byte_out() messy.
698 */
699 if (scsi_pointer->this_residual & 0x01)
700 scsi_pointer->this_residual++;
701 }
702 }
703 /* Now check to see if the drive is ready to comunicate */
704 w_ctr(ppb, 0x0c);
705 r = (r_str(ppb) & 0xb8);
706
707 /* If not, drop back down to the scheduler and wait a timer tick */
708 if (!(r & 0x80))
709 return 0;
710 }
711 return 1; /* FINISH_RETURN */
712 }
713
714 /*
715 * Since the IMM itself doesn't generate interrupts, we use
716 * the scheduler's task queue to generate a stream of call-backs and
717 * complete the request when the drive is ready.
718 */
imm_interrupt(struct work_struct * work)719 static void imm_interrupt(struct work_struct *work)
720 {
721 imm_struct *dev = container_of(work, imm_struct, imm_tq.work);
722 struct scsi_cmnd *cmd = dev->cur_cmd;
723 struct Scsi_Host *host = cmd->device->host;
724 unsigned long flags;
725
726 if (imm_engine(dev, cmd)) {
727 schedule_delayed_work(&dev->imm_tq, 1);
728 return;
729 }
730 /* Command must of completed hence it is safe to let go... */
731 #if IMM_DEBUG > 0
732 switch ((cmd->result >> 16) & 0xff) {
733 case DID_OK:
734 break;
735 case DID_NO_CONNECT:
736 printk("imm: no device at SCSI ID %i\n", cmd->device->id);
737 break;
738 case DID_BUS_BUSY:
739 printk("imm: BUS BUSY - EPP timeout detected\n");
740 break;
741 case DID_TIME_OUT:
742 printk("imm: unknown timeout\n");
743 break;
744 case DID_ABORT:
745 printk("imm: told to abort\n");
746 break;
747 case DID_PARITY:
748 printk("imm: parity error (???)\n");
749 break;
750 case DID_ERROR:
751 printk("imm: internal driver error\n");
752 break;
753 case DID_RESET:
754 printk("imm: told to reset device\n");
755 break;
756 case DID_BAD_INTR:
757 printk("imm: bad interrupt (???)\n");
758 break;
759 default:
760 printk("imm: bad return code (%02x)\n",
761 (cmd->result >> 16) & 0xff);
762 }
763 #endif
764
765 if (imm_scsi_pointer(cmd)->phase > 1)
766 imm_disconnect(dev);
767
768 imm_pb_dismiss(dev);
769
770 spin_lock_irqsave(host->host_lock, flags);
771 dev->cur_cmd = NULL;
772 scsi_done(cmd);
773 spin_unlock_irqrestore(host->host_lock, flags);
774 return;
775 }
776
imm_engine(imm_struct * dev,struct scsi_cmnd * const cmd)777 static int imm_engine(imm_struct *dev, struct scsi_cmnd *const cmd)
778 {
779 struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);
780 unsigned short ppb = dev->base;
781 unsigned char l = 0, h = 0;
782 int retv, x;
783
784 /* First check for any errors that may have occurred
785 * Here we check for internal errors
786 */
787 if (dev->failed)
788 return 0;
789
790 switch (scsi_pointer->phase) {
791 case 0: /* Phase 0 - Waiting for parport */
792 if (time_after(jiffies, dev->jstart + HZ)) {
793 /*
794 * We waited more than a second
795 * for parport to call us
796 */
797 imm_fail(dev, DID_BUS_BUSY);
798 return 0;
799 }
800 return 1; /* wait until imm_wakeup claims parport */
801
802 case 1: /* Phase 1 - Connected */
803 imm_connect(dev, CONNECT_EPP_MAYBE);
804 scsi_pointer->phase++;
805 fallthrough;
806
807 case 2: /* Phase 2 - We are now talking to the scsi bus */
808 if (!imm_select(dev, scmd_id(cmd))) {
809 imm_fail(dev, DID_NO_CONNECT);
810 return 0;
811 }
812 scsi_pointer->phase++;
813 fallthrough;
814
815 case 3: /* Phase 3 - Ready to accept a command */
816 w_ctr(ppb, 0x0c);
817 if (!(r_str(ppb) & 0x80))
818 return 1;
819
820 if (!imm_send_command(cmd))
821 return 0;
822 scsi_pointer->phase++;
823 fallthrough;
824
825 case 4: /* Phase 4 - Setup scatter/gather buffers */
826 if (scsi_bufflen(cmd)) {
827 scsi_pointer->buffer = scsi_sglist(cmd);
828 scsi_pointer->this_residual = scsi_pointer->buffer->length;
829 scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
830 } else {
831 scsi_pointer->buffer = NULL;
832 scsi_pointer->this_residual = 0;
833 scsi_pointer->ptr = NULL;
834 }
835 scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;
836 scsi_pointer->phase++;
837 if (scsi_pointer->this_residual & 0x01)
838 scsi_pointer->this_residual++;
839 fallthrough;
840
841 case 5: /* Phase 5 - Pre-Data transfer stage */
842 /* Spin lock for BUSY */
843 w_ctr(ppb, 0x0c);
844 if (!(r_str(ppb) & 0x80))
845 return 1;
846
847 /* Require negotiation for read requests */
848 x = (r_str(ppb) & 0xb8);
849 dev->rd = (x & 0x10) ? 1 : 0;
850 dev->dp = (x & 0x20) ? 0 : 1;
851
852 if ((dev->dp) && (dev->rd))
853 if (imm_negotiate(dev))
854 return 0;
855 scsi_pointer->phase++;
856 fallthrough;
857
858 case 6: /* Phase 6 - Data transfer stage */
859 /* Spin lock for BUSY */
860 w_ctr(ppb, 0x0c);
861 if (!(r_str(ppb) & 0x80))
862 return 1;
863
864 if (dev->dp) {
865 retv = imm_completion(cmd);
866 if (retv == -1)
867 return 0;
868 if (retv == 0)
869 return 1;
870 }
871 scsi_pointer->phase++;
872 fallthrough;
873
874 case 7: /* Phase 7 - Post data transfer stage */
875 if ((dev->dp) && (dev->rd)) {
876 if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
877 w_ctr(ppb, 0x4);
878 w_ctr(ppb, 0xc);
879 w_ctr(ppb, 0xe);
880 w_ctr(ppb, 0x4);
881 }
882 }
883 scsi_pointer->phase++;
884 fallthrough;
885
886 case 8: /* Phase 8 - Read status/message */
887 /* Check for data overrun */
888 if (imm_wait(dev) != (unsigned char) 0xb8) {
889 imm_fail(dev, DID_ERROR);
890 return 0;
891 }
892 if (imm_negotiate(dev))
893 return 0;
894 if (imm_in(dev, &l, 1)) { /* read status byte */
895 /* Check for optional message byte */
896 if (imm_wait(dev) == (unsigned char) 0xb8)
897 imm_in(dev, &h, 1);
898 cmd->result = (DID_OK << 16) | (l & STATUS_MASK);
899 }
900 if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
901 w_ctr(ppb, 0x4);
902 w_ctr(ppb, 0xc);
903 w_ctr(ppb, 0xe);
904 w_ctr(ppb, 0x4);
905 }
906 return 0; /* Finished */
907
908 default:
909 printk("imm: Invalid scsi phase\n");
910 }
911 return 0;
912 }
913
imm_queuecommand_lck(struct scsi_cmnd * cmd)914 static int imm_queuecommand_lck(struct scsi_cmnd *cmd)
915 {
916 imm_struct *dev = imm_dev(cmd->device->host);
917
918 if (dev->cur_cmd) {
919 printk("IMM: bug in imm_queuecommand\n");
920 return 0;
921 }
922 dev->failed = 0;
923 dev->jstart = jiffies;
924 dev->cur_cmd = cmd;
925 cmd->result = DID_ERROR << 16; /* default return code */
926 imm_scsi_pointer(cmd)->phase = 0; /* bus free */
927
928 schedule_delayed_work(&dev->imm_tq, 0);
929
930 imm_pb_claim(dev);
931
932 return 0;
933 }
934
DEF_SCSI_QCMD(imm_queuecommand)935 static DEF_SCSI_QCMD(imm_queuecommand)
936
937 /*
938 * Apparently the disk->capacity attribute is off by 1 sector
939 * for all disk drives. We add the one here, but it should really
940 * be done in sd.c. Even if it gets fixed there, this will still
941 * work.
942 */
943 static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,
944 sector_t capacity, int ip[])
945 {
946 ip[0] = 0x40;
947 ip[1] = 0x20;
948 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
949 if (ip[2] > 1024) {
950 ip[0] = 0xff;
951 ip[1] = 0x3f;
952 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
953 }
954 return 0;
955 }
956
imm_abort(struct scsi_cmnd * cmd)957 static int imm_abort(struct scsi_cmnd *cmd)
958 {
959 imm_struct *dev = imm_dev(cmd->device->host);
960 /*
961 * There is no method for aborting commands since Iomega
962 * have tied the SCSI_MESSAGE line high in the interface
963 */
964
965 switch (imm_scsi_pointer(cmd)->phase) {
966 case 0: /* Do not have access to parport */
967 case 1: /* Have not connected to interface */
968 dev->cur_cmd = NULL; /* Forget the problem */
969 return SUCCESS;
970 default: /* SCSI command sent, can not abort */
971 return FAILED;
972 }
973 }
974
imm_reset_pulse(unsigned int base)975 static void imm_reset_pulse(unsigned int base)
976 {
977 w_ctr(base, 0x04);
978 w_dtr(base, 0x40);
979 udelay(1);
980 w_ctr(base, 0x0c);
981 w_ctr(base, 0x0d);
982 udelay(50);
983 w_ctr(base, 0x0c);
984 w_ctr(base, 0x04);
985 }
986
imm_reset(struct scsi_cmnd * cmd)987 static int imm_reset(struct scsi_cmnd *cmd)
988 {
989 imm_struct *dev = imm_dev(cmd->device->host);
990
991 if (imm_scsi_pointer(cmd)->phase)
992 imm_disconnect(dev);
993 dev->cur_cmd = NULL; /* Forget the problem */
994
995 imm_connect(dev, CONNECT_NORMAL);
996 imm_reset_pulse(dev->base);
997 mdelay(1); /* device settle delay */
998 imm_disconnect(dev);
999 mdelay(1); /* device settle delay */
1000 return SUCCESS;
1001 }
1002
device_check(imm_struct * dev)1003 static int device_check(imm_struct *dev)
1004 {
1005 /* This routine looks for a device and then attempts to use EPP
1006 to send a command. If all goes as planned then EPP is available. */
1007
1008 static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
1009 int loop, old_mode, status, k, ppb = dev->base;
1010 unsigned char l;
1011
1012 old_mode = dev->mode;
1013 for (loop = 0; loop < 8; loop++) {
1014 /* Attempt to use EPP for Test Unit Ready */
1015 if ((ppb & 0x0007) == 0x0000)
1016 dev->mode = IMM_EPP_32;
1017
1018 second_pass:
1019 imm_connect(dev, CONNECT_EPP_MAYBE);
1020 /* Select SCSI device */
1021 if (!imm_select(dev, loop)) {
1022 imm_disconnect(dev);
1023 continue;
1024 }
1025 printk("imm: Found device at ID %i, Attempting to use %s\n",
1026 loop, IMM_MODE_STRING[dev->mode]);
1027
1028 /* Send SCSI command */
1029 status = 1;
1030 w_ctr(ppb, 0x0c);
1031 for (l = 0; (l < 3) && (status); l++)
1032 status = imm_out(dev, &cmd[l << 1], 2);
1033
1034 if (!status) {
1035 imm_disconnect(dev);
1036 imm_connect(dev, CONNECT_EPP_MAYBE);
1037 imm_reset_pulse(dev->base);
1038 udelay(1000);
1039 imm_disconnect(dev);
1040 udelay(1000);
1041 if (dev->mode == IMM_EPP_32) {
1042 dev->mode = old_mode;
1043 goto second_pass;
1044 }
1045 printk("imm: Unable to establish communication\n");
1046 return -EIO;
1047 }
1048 w_ctr(ppb, 0x0c);
1049
1050 k = 1000000; /* 1 Second */
1051 do {
1052 l = r_str(ppb);
1053 k--;
1054 udelay(1);
1055 } while (!(l & 0x80) && (k));
1056
1057 l &= 0xb8;
1058
1059 if (l != 0xb8) {
1060 imm_disconnect(dev);
1061 imm_connect(dev, CONNECT_EPP_MAYBE);
1062 imm_reset_pulse(dev->base);
1063 udelay(1000);
1064 imm_disconnect(dev);
1065 udelay(1000);
1066 if (dev->mode == IMM_EPP_32) {
1067 dev->mode = old_mode;
1068 goto second_pass;
1069 }
1070 printk
1071 ("imm: Unable to establish communication\n");
1072 return -EIO;
1073 }
1074 imm_disconnect(dev);
1075 printk
1076 ("imm: Communication established at 0x%x with ID %i using %s\n",
1077 ppb, loop, IMM_MODE_STRING[dev->mode]);
1078 imm_connect(dev, CONNECT_EPP_MAYBE);
1079 imm_reset_pulse(dev->base);
1080 udelay(1000);
1081 imm_disconnect(dev);
1082 udelay(1000);
1083 return 0;
1084 }
1085 printk("imm: No devices found\n");
1086 return -ENODEV;
1087 }
1088
1089 /*
1090 * imm cannot deal with highmem, so this causes all IO pages for this host
1091 * to reside in low memory (hence mapped)
1092 */
imm_adjust_queue(struct scsi_device * device)1093 static int imm_adjust_queue(struct scsi_device *device)
1094 {
1095 blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
1096 return 0;
1097 }
1098
1099 static const struct scsi_host_template imm_template = {
1100 .module = THIS_MODULE,
1101 .proc_name = "imm",
1102 .show_info = imm_show_info,
1103 .write_info = imm_write_info,
1104 .name = "Iomega VPI2 (imm) interface",
1105 .queuecommand = imm_queuecommand,
1106 .eh_abort_handler = imm_abort,
1107 .eh_host_reset_handler = imm_reset,
1108 .bios_param = imm_biosparam,
1109 .this_id = 7,
1110 .sg_tablesize = SG_ALL,
1111 .can_queue = 1,
1112 .slave_alloc = imm_adjust_queue,
1113 .cmd_size = sizeof(struct scsi_pointer),
1114 };
1115
1116 /***************************************************************************
1117 * Parallel port probing routines *
1118 ***************************************************************************/
1119
1120 static LIST_HEAD(imm_hosts);
1121
1122 /*
1123 * Finds the first available device number that can be alloted to the
1124 * new imm device and returns the address of the previous node so that
1125 * we can add to the tail and have a list in the ascending order.
1126 */
1127
find_parent(void)1128 static inline imm_struct *find_parent(void)
1129 {
1130 imm_struct *dev, *par = NULL;
1131 unsigned int cnt = 0;
1132
1133 if (list_empty(&imm_hosts))
1134 return NULL;
1135
1136 list_for_each_entry(dev, &imm_hosts, list) {
1137 if (dev->dev_no != cnt)
1138 return par;
1139 cnt++;
1140 par = dev;
1141 }
1142
1143 return par;
1144 }
1145
__imm_attach(struct parport * pb)1146 static int __imm_attach(struct parport *pb)
1147 {
1148 struct Scsi_Host *host;
1149 imm_struct *dev, *temp;
1150 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1151 DEFINE_WAIT(wait);
1152 int ports;
1153 int modes, ppb;
1154 int err = -ENOMEM;
1155 struct pardev_cb imm_cb;
1156
1157 init_waitqueue_head(&waiting);
1158
1159 dev = kzalloc(sizeof(imm_struct), GFP_KERNEL);
1160 if (!dev)
1161 return -ENOMEM;
1162
1163
1164 dev->base = -1;
1165 dev->mode = IMM_AUTODETECT;
1166 INIT_LIST_HEAD(&dev->list);
1167
1168 temp = find_parent();
1169 if (temp)
1170 dev->dev_no = temp->dev_no + 1;
1171
1172 memset(&imm_cb, 0, sizeof(imm_cb));
1173 imm_cb.private = dev;
1174 imm_cb.wakeup = imm_wakeup;
1175
1176 dev->dev = parport_register_dev_model(pb, "imm", &imm_cb, dev->dev_no);
1177 if (!dev->dev)
1178 goto out;
1179
1180
1181 /* Claim the bus so it remembers what we do to the control
1182 * registers. [ CTR and ECP ]
1183 */
1184 err = -EBUSY;
1185 dev->waiting = &waiting;
1186 prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1187 if (imm_pb_claim(dev))
1188 schedule_timeout(3 * HZ);
1189 if (dev->wanted) {
1190 printk(KERN_ERR "imm%d: failed to claim parport because "
1191 "a pardevice is owning the port for too long "
1192 "time!\n", pb->number);
1193 imm_pb_dismiss(dev);
1194 dev->waiting = NULL;
1195 finish_wait(&waiting, &wait);
1196 goto out1;
1197 }
1198 dev->waiting = NULL;
1199 finish_wait(&waiting, &wait);
1200 ppb = dev->base = dev->dev->port->base;
1201 dev->base_hi = dev->dev->port->base_hi;
1202 w_ctr(ppb, 0x0c);
1203 modes = dev->dev->port->modes;
1204
1205 /* Mode detection works up the chain of speed
1206 * This avoids a nasty if-then-else-if-... tree
1207 */
1208 dev->mode = IMM_NIBBLE;
1209
1210 if (modes & PARPORT_MODE_TRISTATE)
1211 dev->mode = IMM_PS2;
1212
1213 /* Done configuration */
1214
1215 err = imm_init(dev);
1216
1217 imm_pb_release(dev);
1218
1219 if (err)
1220 goto out1;
1221
1222 /* now the glue ... */
1223 if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)
1224 ports = 3;
1225 else
1226 ports = 8;
1227
1228 INIT_DELAYED_WORK(&dev->imm_tq, imm_interrupt);
1229
1230 err = -ENOMEM;
1231 host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));
1232 if (!host)
1233 goto out1;
1234 host->io_port = pb->base;
1235 host->n_io_port = ports;
1236 host->dma_channel = -1;
1237 host->unique_id = pb->number;
1238 *(imm_struct **)&host->hostdata = dev;
1239 dev->host = host;
1240 if (!temp)
1241 list_add_tail(&dev->list, &imm_hosts);
1242 else
1243 list_add_tail(&dev->list, &temp->list);
1244 err = scsi_add_host(host, NULL);
1245 if (err)
1246 goto out2;
1247 scsi_scan_host(host);
1248 return 0;
1249
1250 out2:
1251 list_del_init(&dev->list);
1252 scsi_host_put(host);
1253 out1:
1254 parport_unregister_device(dev->dev);
1255 out:
1256 kfree(dev);
1257 return err;
1258 }
1259
imm_attach(struct parport * pb)1260 static void imm_attach(struct parport *pb)
1261 {
1262 __imm_attach(pb);
1263 }
1264
imm_detach(struct parport * pb)1265 static void imm_detach(struct parport *pb)
1266 {
1267 imm_struct *dev;
1268 list_for_each_entry(dev, &imm_hosts, list) {
1269 if (dev->dev->port == pb) {
1270 list_del_init(&dev->list);
1271 scsi_remove_host(dev->host);
1272 scsi_host_put(dev->host);
1273 parport_unregister_device(dev->dev);
1274 kfree(dev);
1275 break;
1276 }
1277 }
1278 }
1279
1280 static struct parport_driver imm_driver = {
1281 .name = "imm",
1282 .match_port = imm_attach,
1283 .detach = imm_detach,
1284 .devmodel = true,
1285 };
1286 module_parport_driver(imm_driver);
1287
1288 MODULE_LICENSE("GPL");
1289