summaryrefslogtreecommitdiffstats
path: root/drivers/sbus/char/bpp.c
blob: ac7d1258efee13610244b8e7a81feaf4a0348c7f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
/*
 * drivers/sbus/char/bpp.c
 *
 * Copyright (c) 1995 Picture Elements
 *      Stephen Williams (steve@icarus.com)
 *      Gus Baldauf (gbaldauf@ix.netcom.com)
 *
 * Linux/SPARC port by Peter Zaitcev.
 * Integration into SPARC tree by Tom Dyas.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/ioport.h>
#include <linux/major.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#if defined(__i386__)
# include <asm/system.h>
#endif

#if defined(__sparc__)
# include <linux/init.h>
# include <linux/delay.h>         /* udelay() */

# include <asm/oplib.h>           /* OpenProm Library */
# include <asm/sbus.h>
#endif

#include <asm/bpp.h>

#define BPP_PROBE_CODE 0x55
#define BPP_DELAY 100

static const unsigned  BPP_MAJOR = LP_MAJOR;
static const char* dev_name = "bpp";

/* When switching from compatibility to a mode where I can read, try
   the following mode first. */

/* const unsigned char DEFAULT_ECP = 0x10; */
static const unsigned char DEFAULT_ECP = 0x30;
static const unsigned char DEFAULT_NIBBLE = 0x00;

/*
 * These are 1284 time constraints, in units of jiffies.
 */

static const unsigned long TIME_PSetup = 1;
static const unsigned long TIME_PResponse = 6;
static const unsigned long TIME_IDLE_LIMIT = 2000;

/*
 * One instance per supported subdevice...
 */
# define BPP_NO 3

enum IEEE_Mode { COMPATIBILITY, NIBBLE, ECP, ECP_RLE, EPP };

struct inst {
      unsigned present  : 1; /* True if the hardware exists */
      unsigned enhanced : 1; /* True if the hardware in "enhanced" */
      unsigned opened   : 1; /* True if the device is opened already */
      unsigned run_flag : 1; /* True if waiting for a repeate byte */

      unsigned char direction; /* 0 --> out, 0x20 --> IN */
      unsigned char pp_state; /* State of host controlled pins. */
      enum IEEE_Mode mode;

      unsigned char run_length;
      unsigned char repeat_byte;
};

static struct inst instances[BPP_NO];

#if defined(__i386__)

static const unsigned short base_addrs[BPP_NO] = { 0x278, 0x378, 0x3bc };

/*
 * These are for data access.
 * Control lines accesses are hidden in set_bits() and get_bits().
 * The exception is the probe procedure, which is system-dependent.
 */
#define bpp_outb_p(data, base)  outb_p((data), (base))
#define bpp_inb(base)  inb(base)
#define bpp_inb_p(base)  inb_p(base)

/*
 * This method takes the pin values mask and sets the hardware pins to
 * the requested value: 1 == high voltage, 0 == low voltage. This
 * burries the annoying PC bit inversion and preserves the direction
 * flag.
 */
static void set_pins(unsigned short pins, unsigned minor)
{
      unsigned char bits = instances[minor].direction;  /* == 0x20 */

      if (! (pins & BPP_PP_nStrobe))   bits |= 1;
      if (! (pins & BPP_PP_nAutoFd))   bits |= 2;
      if (   pins & BPP_PP_nInit)      bits |= 4;
      if (! (pins & BPP_PP_nSelectIn)) bits |= 8;

      instances[minor].pp_state = bits;

      outb_p(bits, base_addrs[minor]+2);
}

static unsigned short get_pins(unsigned minor)
{
      unsigned short bits = 0;

      unsigned value = instances[minor].pp_state;
      if (! (value & 0x01)) bits |= BPP_PP_nStrobe;
      if (! (value & 0x02)) bits |= BPP_PP_nAutoFd;
      if (value & 0x04)     bits |= BPP_PP_nInit;
      if (! (value & 0x08)) bits |= BPP_PP_nSelectIn;

      value = inb_p(base_addrs[minor]+1);
      if (value & 0x08)     bits |= BPP_GP_nFault;
      if (value & 0x10)     bits |= BPP_GP_Select;
      if (value & 0x20)     bits |= BPP_GP_PError;
      if (value & 0x40)     bits |= BPP_GP_nAck;
      if (! (value & 0x80)) bits |= BPP_GP_Busy;

      return bits;
}

#endif /* __i386__ */

#if defined(__sparc__)

/*
 * Register block
 */
      /* DMA registers */
#define BPP_CSR      0x00
#define BPP_ADDR     0x04
#define BPP_BCNT     0x08
#define BPP_TST_CSR  0x0C
      /* Parallel Port registers */
#define BPP_HCR      0x10
#define BPP_OCR      0x12
#define BPP_DR       0x14
#define BPP_TCR      0x15
#define BPP_OR       0x16
#define BPP_IR       0x17
#define BPP_ICR      0x18
#define BPP_SIZE     0x1A

/* BPP_CSR.  Bits of type RW1 are cleared with writting '1'. */
#define P_DEV_ID_MASK   0xf0000000      /* R   */
#define P_DEV_ID_ZEBRA  0x40000000
#define P_DEV_ID_L64854 0xa0000000      /*      == NCR 89C100+89C105. Pity. */
#define P_NA_LOADED     0x08000000      /* R    NA wirtten but was not used */
#define P_A_LOADED      0x04000000      /* R    */
#define P_DMA_ON        0x02000000      /* R    DMA is not disabled */
#define P_EN_NEXT       0x01000000      /* RW   */
#define P_TCI_DIS       0x00800000      /* RW   TCI forbidden from interrupts */
#define P_DIAG          0x00100000      /* RW   Disables draining and resetting
                                                of P-FIFO on loading of P_ADDR*/
#define P_BURST_SIZE    0x000c0000      /* RW   SBus burst size */
#define P_BURST_8       0x00000000
#define P_BURST_4       0x00040000
#define P_BURST_1       0x00080000      /*      "No burst" write */
#define P_TC            0x00004000      /* RW1  Term Count, can be cleared when
                                           P_EN_NEXT=1 */
#define P_EN_CNT        0x00002000      /* RW   */
#define P_EN_DMA        0x00000200      /* RW   */
#define P_WRITE         0x00000100      /* R    DMA dir, 1=to ram, 0=to port */
#define P_RESET         0x00000080      /* RW   */
#define P_SLAVE_ERR     0x00000040      /* RW1  Access size error */
#define P_INVALIDATE    0x00000020      /* W    Drop P-FIFO */
#define P_INT_EN        0x00000010      /* RW   OK to P_INT_PEND||P_ERR_PEND */
#define P_DRAINING      0x0000000c      /* R    P-FIFO is draining to memory */
#define P_ERR_PEND      0x00000002      /* R    */
#define P_INT_PEND      0x00000001      /* R    */

/* BPP_HCR. Time is in increments of SBus clock. */
#define P_HCR_TEST      0x8000      /* Allows buried counters to be read */
#define P_HCR_DSW       0x7f00      /* Data strobe width (in ticks) */
#define P_HCR_DDS       0x007f      /* Data setup before strobe (in ticks) */

/* BPP_OCR. */
#define P_OCR_MEM_CLR   0x8000
#define P_OCR_DATA_SRC  0x4000      /* )                  */
#define P_OCR_DS_DSEL   0x2000      /* )  Bidirectional      */
#define P_OCR_BUSY_DSEL 0x1000      /* )    selects            */
#define P_OCR_ACK_DSEL  0x0800      /* )                  */
#define P_OCR_EN_DIAG   0x0400
#define P_OCR_BUSY_OP   0x0200      /* Busy operation */
#define P_OCR_ACK_OP    0x0100      /* Ack operation */
#define P_OCR_SRST      0x0080      /* Reset state machines. Not selfcleaning. */
#define P_OCR_IDLE      0x0008      /* PP data transfer state machine is idle */
#define P_OCR_V_ILCK    0x0002      /* Versatec faded. Zebra only. */
#define P_OCR_EN_VER    0x0001      /* Enable Versatec (0 - enable). Zebra only. */

/* BPP_TCR */
#define P_TCR_DIR       0x08
#define P_TCR_BUSY      0x04
#define P_TCR_ACK       0x02
#define P_TCR_DS        0x01        /* Strobe */

/* BPP_OR */
#define P_OR_V3         0x20        /* )                 */
#define P_OR_V2         0x10        /* ) on Zebra only   */
#define P_OR_V1         0x08        /* )                 */
#define P_OR_INIT       0x04
#define P_OR_AFXN       0x02        /* Auto Feed */
#define P_OR_SLCT_IN    0x01

/* BPP_IR */
#define P_IR_PE         0x04
#define P_IR_SLCT       0x02
#define P_IR_ERR        0x01

/* BPP_ICR */
#define P_DS_IRQ        0x8000      /* RW1  */
#define P_ACK_IRQ       0x4000      /* RW1  */
#define P_BUSY_IRQ      0x2000      /* RW1  */
#define P_PE_IRQ        0x1000      /* RW1  */
#define P_SLCT_IRQ      0x0800      /* RW1  */
#define P_ERR_IRQ       0x0400      /* RW1  */
#define P_DS_IRQ_EN     0x0200      /* RW   Always on rising edge */
#define P_ACK_IRQ_EN    0x0100      /* RW   Always on rising edge */
#define P_BUSY_IRP      0x0080      /* RW   1= rising edge */
#define P_BUSY_IRQ_EN   0x0040      /* RW   */
#define P_PE_IRP        0x0020      /* RW   1= rising edge */
#define P_PE_IRQ_EN     0x0010      /* RW   */
#define P_SLCT_IRP      0x0008      /* RW   1= rising edge */
#define P_SLCT_IRQ_EN   0x0004      /* RW   */
#define P_ERR_IRP       0x0002      /* RW1  1= rising edge */
#define P_ERR_IRQ_EN    0x0001      /* RW   */

static void __iomem *base_addrs[BPP_NO];

#define bpp_outb_p(data, base)	sbus_writeb(data, (base) + BPP_DR)
#define bpp_inb_p(base)		sbus_readb((base) + BPP_DR)
#define bpp_inb(base)		sbus_readb((base) + BPP_DR)

static void set_pins(unsigned short pins, unsigned minor)
{
      void __iomem *base = base_addrs[minor];
      unsigned char bits_tcr = 0, bits_or = 0;

      if (instances[minor].direction & 0x20) bits_tcr |= P_TCR_DIR;
      if (   pins & BPP_PP_nStrobe)          bits_tcr |= P_TCR_DS;

      if (   pins & BPP_PP_nAutoFd)          bits_or |= P_OR_AFXN;
      if (! (pins & BPP_PP_nInit))           bits_or |= P_OR_INIT;
      if (! (pins & BPP_PP_nSelectIn))       bits_or |= P_OR_SLCT_IN;

      sbus_writeb(bits_or, base + BPP_OR);
      sbus_writeb(bits_tcr, base + BPP_TCR);
}

/*
 * i386 people read output pins from a software image.
 * We may get them back from hardware.
 * Again, inversion of pins must he buried here.
 */
static unsigned short get_pins(unsigned minor)
{
      void __iomem *base = base_addrs[minor];
      unsigned short bits = 0;
      unsigned value_tcr = sbus_readb(base + BPP_TCR);
      unsigned value_ir = sbus_readb(base + BPP_IR);
      unsigned value_or = sbus_readb(base + BPP_OR);

      if (value_tcr & P_TCR_DS)         bits |= BPP_PP_nStrobe;
      if (value_or & P_OR_AFXN)         bits |= BPP_PP_nAutoFd;
      if (! (value_or & P_OR_INIT))     bits |= BPP_PP_nInit;
      if (! (value_or & P_OR_SLCT_IN))  bits |= BPP_PP_nSelectIn;

      if (value_ir & P_IR_ERR)          bits |= BPP_GP_nFault;
      if (! (value_ir & P_IR_SLCT))     bits |= BPP_GP_Select;
      if (! (value_ir & P_IR_PE))       bits |= BPP_GP_PError;
      if (! (value_tcr & P_TCR_ACK))    bits |= BPP_GP_nAck;
      if (value_tcr & P_TCR_BUSY)       bits |= BPP_GP_Busy;

      return bits;
}

#endif /* __sparc__ */

static void snooze(unsigned long snooze_time, unsigned minor)
{
	schedule_timeout_uninterruptible(snooze_time + 1);
}

static int wait_for(unsigned short set, unsigned short clr,
               unsigned long delay, unsigned minor)
{
      unsigned short pins = get_pins(minor);

      unsigned long extime = 0;

      /*
       * Try a real fast scan for the first jiffy, in case the device
       * responds real good. The first while loop guesses an expire
       * time accounting for possible wraparound of jiffies.
       */
      while (time_after_eq(jiffies, extime)) extime = jiffies + 1;
      while ( (time_before(jiffies, extime))
              && (((pins & set) != set) || ((pins & clr) != 0)) ) {
            pins = get_pins(minor);
      }

      delay -= 1;

      /*
       * If my delay expired or the pins are still not where I want
       * them, then resort to using the timer and greatly reduce my
       * sample rate. If the peripheral is going to be slow, this will
       * give the CPU up to some more worthy process.
       */
      while ( delay && (((pins & set) != set) || ((pins & clr) != 0)) ) {

            snooze(1, minor);
            pins = get_pins(minor);
            delay -= 1;
      }

      if (delay == 0) return -1;
      else return pins;
}

/*
 * Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
 * errno means something broke, and I do not yet know how to fix it.
 */
static int negotiate(unsigned char mode, unsigned minor)
{
      int rc;
      unsigned short pins = get_pins(minor);
      if (pins & BPP_PP_nSelectIn) return -EIO;


        /* Event 0: Write the mode to the data lines */
      bpp_outb_p(mode, base_addrs[minor]);

      snooze(TIME_PSetup, minor);

        /* Event 1: Strobe the mode code into the peripheral */
      set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);

        /* Wait for Event 2: Peripheral responds as a 1284 device. */
      rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
                BPP_GP_nAck,
                TIME_PResponse,
                minor);

      if (rc == -1) return -ETIMEDOUT;

        /* Event 3: latch extensibility request */
      set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);

        /* ... quick nap while peripheral ponders the byte i'm sending...*/
      snooze(1, minor);

        /* Event 4: restore strobe, to ACK peripheral's response. */
      set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);

        /* Wait for Event 6: Peripheral latches response bits */
      rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
      if (rc == -1) return -EIO;

        /* A 1284 device cannot refuse nibble mode */
      if (mode == DEFAULT_NIBBLE) return 0;

      if (pins & BPP_GP_Select) return 0;

      return -EPROTONOSUPPORT;
}

static int terminate(unsigned minor)
{
      int rc;

        /* Event 22: Request termination of 1284 mode */
      set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);

        /* Wait for Events 23 and 24: ACK termination request. */
      rc = wait_for(BPP_GP_Busy|BPP_GP_nFault,
                BPP_GP_nAck,
                TIME_PSetup+TIME_PResponse,
                minor);

      instances[minor].direction = 0;
      instances[minor].mode = COMPATIBILITY;

      if (rc == -1) {
          return -EIO;
      }

        /* Event 25: Handshake by lowering nAutoFd */
      set_pins(BPP_PP_nStrobe|BPP_PP_nInit, minor);

        /* Event 26: Peripheral wiggles lines... */

        /* Event 27: Peripheral sets nAck HIGH to ack handshake */
      rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
      if (rc == -1) {
          set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
          return -EIO;
      }

        /* Event 28: Finish phase by raising nAutoFd */
      set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);

      return 0;
}

static DEFINE_SPINLOCK(bpp_open_lock);

/*
 * Allow only one process to open the device at a time.
 */
static int bpp_open(struct inode *inode, struct file *f)
{
      unsigned minor = iminor(inode);
      int ret;

      spin_lock(&bpp_open_lock);
      ret = 0;
      if (minor >= BPP_NO) {
	      ret = -ENODEV;
      } else {
	      if (! instances[minor].present) {
		      ret = -ENODEV;
	      } else {
		      if (instances[minor].opened) 
			      ret = -EBUSY;
		      else
			      instances[minor].opened = 1;
	      }
      }
      spin_unlock(&bpp_open_lock);

      return ret;
}

/*
 * When the process closes the device, this method is called to clean
 * up and reset the hardware. Always leave the device in compatibility
 * mode as this is a reasonable place to clean up from messes made by
 * ioctls, or other mayhem.
 */
static int bpp_release(struct inode *inode, struct file *f)
{
      unsigned minor = iminor(inode);

      spin_lock(&bpp_open_lock);
      instances[minor].opened = 0;

      if (instances[minor].mode != COMPATIBILITY)
	      terminate(minor);

      spin_unlock(&bpp_open_lock);

      return 0;
}

static long read_nibble(unsigned minor, char __user *c, unsigned long cnt)
{
      unsigned long remaining = cnt;
      long rc;

      while (remaining > 0) {
          unsigned char byte = 0;
          int pins;

          /* Event 7: request nibble */
          set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);

          /* Wait for event 9: Peripher strobes first nibble */
          pins = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
          if (pins == -1) return -ETIMEDOUT;

          /* Event 10: I handshake nibble */
          set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
          if (pins & BPP_GP_nFault) byte |= 0x01;
          if (pins & BPP_GP_Select) byte |= 0x02;
          if (pins & BPP_GP_PError) byte |= 0x04;
          if (pins & BPP_GP_Busy)   byte |= 0x08;

          /* Wait for event 11: Peripheral handshakes nibble */
          rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);

          /* Event 7: request nibble */
          set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);

          /* Wait for event 9: Peripher strobes first nibble */
          pins = wait_for(0, BPP_GP_nAck, TIME_PResponse, minor);
          if (rc == -1) return -ETIMEDOUT;

          /* Event 10: I handshake nibble */
          set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
          if (pins & BPP_GP_nFault) byte |= 0x10;
          if (pins & BPP_GP_Select) byte |= 0x20;
          if (pins & BPP_GP_PError) byte |= 0x40;
          if (pins & BPP_GP_Busy)   byte |= 0x80;

          if (put_user(byte, c))
		  return -EFAULT;
          c += 1;
          remaining -= 1;

          /* Wait for event 11: Peripheral handshakes nibble */
          rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
          if (rc == -1) return -EIO;
      }

      return cnt - remaining;
}

static long read_ecp(unsigned minor, char __user *c, unsigned long cnt)
{
      unsigned long remaining;
      long rc;

        /* Turn ECP mode from forward to reverse if needed. */
      if (! instances[minor].direction) {
          unsigned short pins = get_pins(minor);

            /* Event 38: Turn the bus around */
          instances[minor].direction = 0x20;
          pins &= ~BPP_PP_nAutoFd;
          set_pins(pins, minor);

            /* Event 39: Set pins for reverse mode. */
          snooze(TIME_PSetup, minor);
          set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);

            /* Wait for event 40: Peripheral ready to be strobed */
          rc = wait_for(0, BPP_GP_PError, TIME_PResponse, minor);
          if (rc == -1) return -ETIMEDOUT;
      }

      remaining = cnt;

      while (remaining > 0) {

            /* If there is a run length for a repeated byte, repeat */
            /* that byte a few times. */
          if (instances[minor].run_length && !instances[minor].run_flag) {

              char buffer[128];
              unsigned idx;
              unsigned repeat = remaining < instances[minor].run_length
                                     ? remaining
                               : instances[minor].run_length;

              for (idx = 0 ;  idx < repeat ;  idx += 1)
                buffer[idx] = instances[minor].repeat_byte;

              if (copy_to_user(c, buffer, repeat))
		      return -EFAULT;
              remaining -= repeat;
              c += repeat;
              instances[minor].run_length -= repeat;
          }

          if (remaining == 0) break;


            /* Wait for Event 43: Data active on the bus. */
          rc = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
          if (rc == -1) break;

          if (rc & BPP_GP_Busy) {
                /* OK, this is data. read it in. */
              unsigned char byte = bpp_inb(base_addrs[minor]);
              if (put_user(byte, c))
		      return -EFAULT;
              c += 1;
              remaining -= 1;

              if (instances[minor].run_flag) {
                  instances[minor].repeat_byte = byte;
                  instances[minor].run_flag = 0;
              }

          } else {
              unsigned char byte = bpp_inb(base_addrs[minor]);
              if (byte & 0x80) {
                  printk("bpp%d: "
                         "Ignoring ECP channel %u from device.\n",
                         minor, byte & 0x7f);
              } else {
                  instances[minor].run_length = byte;
                  instances[minor].run_flag = 1;
              }
          }

            /* Event 44: I got it. */
          set_pins(BPP_PP_nStrobe|BPP_PP_nAutoFd|BPP_PP_nSelectIn, minor);

            /* Wait for event 45: peripheral handshake */
          rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
          if (rc == -1) return -ETIMEDOUT;

             /* Event 46: Finish handshake */
          set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);

      }


      return cnt - remaining;
}

static ssize_t bpp_read(struct file *f, char __user *c, size_t cnt, loff_t * ppos)
{
      long rc;
      unsigned minor = iminor(f->f_path.dentry->d_inode);
      if (minor >= BPP_NO) return -ENODEV;
      if (!instances[minor].present) return -ENODEV;

      switch (instances[minor].mode) {

        default:
          if (instances[minor].mode != COMPATIBILITY)
            terminate(minor);

          if (instances[minor].enhanced) {
              /* For now, do all reads with ECP-RLE mode */
              unsigned short pins;

              rc = negotiate(DEFAULT_ECP, minor);
              if (rc < 0) break;

              instances[minor].mode = ECP_RLE;

              /* Event 30: set nAutoFd low to setup for ECP mode */
              pins = get_pins(minor);
              pins &= ~BPP_PP_nAutoFd;
              set_pins(pins, minor);

              /* Wait for Event 31: peripheral ready */
              rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
              if (rc == -1) return -ETIMEDOUT;

              rc = read_ecp(minor, c, cnt);

          } else {
              rc = negotiate(DEFAULT_NIBBLE, minor);
              if (rc < 0) break;

              instances[minor].mode = NIBBLE;

              rc = read_nibble(minor, c, cnt);
          }
          break;

        case NIBBLE:
          rc = read_nibble(minor, c, cnt);
          break;

        case ECP:
        case ECP_RLE:
          rc = read_ecp(minor, c, cnt);
          break;

      }


      return rc;
}

/*
 * Compatibility mode handshaking is a matter of writing data,
 * strobing it, and waiting for the printer to stop being busy.
 */
static long write_compat(unsigned minor, const char __user *c, unsigned long cnt)
{
      long rc;
      unsigned short pins = get_pins(minor);

      unsigned long remaining = cnt;


      while (remaining > 0) {
            unsigned char byte;

            if (get_user(byte, c))
		    return -EFAULT;
            c += 1;

            rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
            if (rc == -1) return -ETIMEDOUT;

            bpp_outb_p(byte, base_addrs[minor]);
            remaining -= 1;
          /* snooze(1, minor); */

          pins &= ~BPP_PP_nStrobe;
          set_pins(pins, minor);

          rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);

          pins |= BPP_PP_nStrobe;
          set_pins(pins, minor);
      }

      return cnt - remaining;
}

/*
 * Write data using ECP mode. Watch out that the port may be set up
 * for reading. If so, turn the port around.
 */
static long write_ecp(unsigned minor, const char __user *c, unsigned long cnt)
{
      unsigned short pins = get_pins(minor);
      unsigned long remaining = cnt;

      if (instances[minor].direction) {
          int rc;

            /* Event 47 Request bus be turned around */
          pins |= BPP_PP_nInit;
          set_pins(pins, minor);

            /* Wait for Event 49: Peripheral relinquished bus */
          rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);

          pins |= BPP_PP_nAutoFd;
          instances[minor].direction = 0;
          set_pins(pins, minor);
      }

      while (remaining > 0) {
          unsigned char byte;
          int rc;

          if (get_user(byte, c))
		  return -EFAULT;

          rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
          if (rc == -1) return -ETIMEDOUT;

          c += 1;

          bpp_outb_p(byte, base_addrs[minor]);

          pins &= ~BPP_PP_nStrobe;
          set_pins(pins, minor);

          pins |= BPP_PP_nStrobe;
          rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
          if (rc == -1) return -EIO;

          set_pins(pins, minor);
      }

      return cnt - remaining;
}

/*
 * Write to the peripheral. Be sensitive of the current mode. If I'm
 * in a mode that can be turned around (ECP) then just do
 * that. Otherwise, terminate and do my writing in compat mode. This
 * is the safest course as any device can handle it.
 */
static ssize_t bpp_write(struct file *f, const char __user *c, size_t cnt, loff_t * ppos)
{
      long errno = 0;
      unsigned minor = iminor(f->f_path.dentry->d_inode);
      if (minor >= BPP_NO) return -ENODEV;
      if (!instances[minor].present) return -ENODEV;

      switch (instances[minor].mode) {

        case ECP:
        case ECP_RLE:
          errno = write_ecp(minor, c, cnt);
          break;
        case COMPATIBILITY:
          errno = write_compat(minor, c, cnt);
          break;
        default:
          terminate(minor);
          errno = write_compat(minor, c, cnt);
      }

      return errno;
}

static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
		 unsigned long arg)
{
      int errno = 0;

      unsigned minor = iminor(inode);
      if (minor >= BPP_NO) return -ENODEV;
      if (!instances[minor].present) return -ENODEV;


      switch (cmd) {

        case BPP_PUT_PINS:
          set_pins(arg, minor);
          break;

        case BPP_GET_PINS:
          errno = get_pins(minor);
          break;

        case BPP_PUT_DATA:
          bpp_outb_p(arg, base_addrs[minor]);
          break;

        case BPP_GET_DATA:
          errno = bpp_inb_p(base_addrs[minor]);
          break;

        case BPP_SET_INPUT:
          if (arg)
            if (instances[minor].enhanced) {
                unsigned short bits = get_pins(minor);
                instances[minor].direction = 0x20;
                set_pins(bits, minor);
            } else {
                errno = -ENOTTY;
            }
          else {
              unsigned short bits = get_pins(minor);
              instances[minor].direction = 0x00;
              set_pins(bits, minor);
          }
          break;

        default:
            errno = -EINVAL;
      }

      return errno;
}

static struct file_operations bpp_fops = {
	.owner =	THIS_MODULE,
	.read =		bpp_read,
	.write =	bpp_write,
	.ioctl =	bpp_ioctl,
	.open =		bpp_open,
	.release =	bpp_release,
};

#if defined(__i386__)

#define collectLptPorts()  {}

static void probeLptPort(unsigned idx)
{
      unsigned int testvalue;
      const unsigned short lpAddr = base_addrs[idx];

      instances[idx].present = 0;
      instances[idx].enhanced = 0;
      instances[idx].direction = 0;
      instances[idx].mode = COMPATIBILITY;
      instances[idx].run_length = 0;
      instances[idx].run_flag = 0;
      if (!request_region(lpAddr,3, dev_name)) return;

      /*
       * First, make sure the instance exists. Do this by writing to
       * the data latch and reading the value back. If the port *is*
       * present, test to see if it supports extended-mode
       * operation. This will be required for IEEE1284 reverse
       * transfers.
       */

      outb_p(BPP_PROBE_CODE, lpAddr);
      for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
            ;
      testvalue = inb_p(lpAddr);
      if (testvalue == BPP_PROBE_CODE) {
            unsigned save;
            instances[idx].present = 1;

            save = inb_p(lpAddr+2);
            for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
                  ;
            outb_p(save|0x20, lpAddr+2);
            for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
                  ;
            outb_p(~BPP_PROBE_CODE, lpAddr);
            for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
                  ;
            testvalue = inb_p(lpAddr);
            if ((testvalue&0xff) == (0xff&~BPP_PROBE_CODE))
                  instances[idx].enhanced = 0;
            else
                  instances[idx].enhanced = 1;
            outb_p(save, lpAddr+2);
      }
      else {
            release_region(lpAddr,3);
      }
      /*
       * Leave the port in compat idle mode.
       */
      set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);

      printk("bpp%d: Port at 0x%03x: Enhanced mode %s\n", idx, base_addrs[idx],
            instances[idx].enhanced? "SUPPORTED" : "UNAVAILABLE");
}

static inline void freeLptPort(int idx)
{
      release_region(base_addrs[idx], 3);
}

#endif

#if defined(__sparc__)

static void __iomem *map_bpp(struct sbus_dev *dev, int idx)
{
      return sbus_ioremap(&dev->resource[0], 0, BPP_SIZE, "bpp");
}

static int collectLptPorts(void)
{
	struct sbus_bus *bus;
	struct sbus_dev *dev;
	int count;

	count = 0;
	for_all_sbusdev(dev, bus) {
		if (strcmp(dev->prom_name, "SUNW,bpp") == 0) {
			if (count >= BPP_NO) {
				printk(KERN_NOTICE
				       "bpp: More than %d bpp ports,"
				       " rest is ignored\n", BPP_NO);
				return count;
			}
			base_addrs[count] = map_bpp(dev, count);
			count++;
		}
	}
	return count;
}

static void probeLptPort(unsigned idx)
{
      void __iomem *rp = base_addrs[idx];
      __u32 csr;
      char *brand;

      instances[idx].present = 0;
      instances[idx].enhanced = 0;
      instances[idx].direction = 0;
      instances[idx].mode = COMPATIBILITY;
      instances[idx].run_length = 0;
      instances[idx].run_flag = 0;

      if (!rp) return;

      instances[idx].present = 1;
      instances[idx].enhanced = 1;   /* Sure */

      csr = sbus_readl(rp + BPP_CSR);
      if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
            udelay(20);
            csr = sbus_readl(rp + BPP_CSR);
            if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
                  printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
            }
      }
      printk("bpp%d: reset with 0x%08x ..", idx, csr);
      sbus_writel((csr | P_RESET) & ~P_INT_EN, rp + BPP_CSR);
      udelay(500);
      sbus_writel(sbus_readl(rp + BPP_CSR) & ~P_RESET, rp + BPP_CSR);
      csr = sbus_readl(rp + BPP_CSR);
      printk(" done with csr=0x%08x ocr=0x%04x\n",
         csr, sbus_readw(rp + BPP_OCR));

      switch (csr & P_DEV_ID_MASK) {
      case P_DEV_ID_ZEBRA:
            brand = "Zebra";
            break;
      case P_DEV_ID_L64854:
            brand = "DMA2";
            break;
      default:
            brand = "Unknown";
      }
      printk("bpp%d: %s at %p\n", idx, brand, rp);

      /*
       * Leave the port in compat idle mode.
       */
      set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);

      return;
}

static inline void freeLptPort(int idx)
{
      sbus_iounmap(base_addrs[idx], BPP_SIZE);
}

#endif

static int __init bpp_init(void)
{
	int rc;
	unsigned idx;

	rc = collectLptPorts();
	if (rc == 0)
		return -ENODEV;

	rc = register_chrdev(BPP_MAJOR, dev_name, &bpp_fops);
	if (rc < 0)
		return rc;

	for (idx = 0; idx < BPP_NO; idx++) {
		instances[idx].opened = 0;
		probeLptPort(idx);
	}

	return 0;
}

static void __exit bpp_cleanup(void)
{
	unsigned idx;

	unregister_chrdev(BPP_MAJOR, dev_name);

	for (idx = 0;  idx < BPP_NO; idx++) {
		if (instances[idx].present)
			freeLptPort(idx);
	}
}

module_init(bpp_init);
module_exit(bpp_cleanup);

MODULE_LICENSE("GPL");

OpenPOWER on IntegriCloud