1 /*
2  * drivers/sbus/char/bpp.c
3  *
4  * Copyright (c) 1995 Picture Elements
5  *      Stephen Williams (steve@icarus.com)
6  *      Gus Baldauf (gbaldauf@ix.netcom.com)
7  *
8  * Linux/SPARC port by Peter Zaitcev.
9  * Integration into SPARC tree by Tom Dyas.
10  */
11 
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/version.h>
16 #include <linux/fs.h>
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/smp_lock.h>
20 #include <linux/spinlock.h>
21 #include <linux/timer.h>
22 #include <linux/ioport.h>
23 #include <linux/major.h>
24 #include <linux/devfs_fs_kernel.h>
25 
26 #include <asm/uaccess.h>
27 #include <asm/io.h>
28 
29 #if defined(__i386__)
30 # include <asm/system.h>
31 # include <asm/segment.h>
32 #endif
33 
34 #if defined(__sparc__)
35 # include <linux/init.h>
36 # include <linux/delay.h>         /* udelay() */
37 
38 # include <asm/oplib.h>           /* OpenProm Library */
39 # include <asm/sbus.h>
40 #endif
41 
42 #include <asm/bpp.h>
43 
44 #define BPP_PROBE_CODE 0x55
45 #define BPP_DELAY 100
46 
47 static const unsigned  BPP_MAJOR = LP_MAJOR;
48 static const char* dev_name = "bpp";
49 
50 /* When switching from compatibility to a mode where I can read, try
51    the following mode first. */
52 
53 /* const unsigned char DEFAULT_ECP = 0x10; */
54 static const unsigned char DEFAULT_ECP = 0x30;
55 static const unsigned char DEFAULT_NIBBLE = 0x00;
56 
57 /*
58  * These are 1284 time constraints, in units of jiffies.
59  */
60 
61 static const unsigned long TIME_PSetup = 1;
62 static const unsigned long TIME_PResponse = 6;
63 static const unsigned long TIME_IDLE_LIMIT = 2000;
64 
65 /*
66  * One instance per supported subdevice...
67  */
68 # define BPP_NO 3
69 
70 enum IEEE_Mode { COMPATIBILITY, NIBBLE, ECP, ECP_RLE, EPP };
71 
72 struct inst {
73       unsigned present  : 1; /* True if the hardware exists */
74       unsigned enhanced : 1; /* True if the hardware in "enhanced" */
75       unsigned opened   : 1; /* True if the device is opened already */
76       unsigned run_flag : 1; /* True if waiting for a repeate byte */
77 
78       unsigned char direction; /* 0 --> out, 0x20 --> IN */
79       unsigned char pp_state; /* State of host controlled pins. */
80       enum IEEE_Mode mode;
81 
82       unsigned char run_length;
83       unsigned char repeat_byte;
84 
85       /* These members manage timeouts for programmed delays */
86       wait_queue_head_t wait_queue;
87       struct timer_list timer_list;
88 };
89 
90 static struct inst instances[BPP_NO];
91 
92 #if defined(__i386__)
93 
94 const unsigned short base_addrs[BPP_NO] = { 0x278, 0x378, 0x3bc };
95 
96 /*
97  * These are for data access.
98  * Control lines accesses are hidden in set_bits() and get_bits().
99  * The exeption is the probe procedure, which is system-dependent.
100  */
101 #define bpp_outb_p(data, base)  outb_p((data), (base))
102 #define bpp_inb(base)  inb(base)
103 #define bpp_inb_p(base)  inb_p(base)
104 
105 /*
106  * This method takes the pin values mask and sets the hardware pins to
107  * the requested value: 1 == high voltage, 0 == low voltage. This
108  * burries the annoying PC bit inversion and preserves the direction
109  * flag.
110  */
set_pins(unsigned short pins,unsigned minor)111 static void set_pins(unsigned short pins, unsigned minor)
112 {
113       unsigned char bits = instances[minor].direction;  /* == 0x20 */
114 
115       if (! (pins & BPP_PP_nStrobe))   bits |= 1;
116       if (! (pins & BPP_PP_nAutoFd))   bits |= 2;
117       if (   pins & BPP_PP_nInit)      bits |= 4;
118       if (! (pins & BPP_PP_nSelectIn)) bits |= 8;
119 
120       instances[minor].pp_state = bits;
121 
122       outb_p(bits, base_addrs[minor]+2);
123 }
124 
get_pins(unsigned minor)125 static unsigned short get_pins(unsigned minor)
126 {
127       unsigned short bits = 0;
128 
129       unsigned value = instances[minor].pp_state;
130       if (! (value & 0x01)) bits |= BPP_PP_nStrobe;
131       if (! (value & 0x02)) bits |= BPP_PP_nAutoFd;
132       if (value & 0x04)     bits |= BPP_PP_nInit;
133       if (! (value & 0x08)) bits |= BPP_PP_nSelectIn;
134 
135       value = inb_p(base_addrs[minor]+1);
136       if (value & 0x08)     bits |= BPP_GP_nFault;
137       if (value & 0x10)     bits |= BPP_GP_Select;
138       if (value & 0x20)     bits |= BPP_GP_PError;
139       if (value & 0x40)     bits |= BPP_GP_nAck;
140       if (! (value & 0x80)) bits |= BPP_GP_Busy;
141 
142       return bits;
143 }
144 
145 #endif /* __i386__ */
146 
147 #if defined(__sparc__)
148 
149 /*
150  * Register block
151  */
152       /* DMA registers */
153 #define BPP_CSR      0x00
154 #define BPP_ADDR     0x04
155 #define BPP_BCNT     0x08
156 #define BPP_TST_CSR  0x0C
157       /* Parallel Port registers */
158 #define BPP_HCR      0x10
159 #define BPP_OCR      0x12
160 #define BPP_DR       0x14
161 #define BPP_TCR      0x15
162 #define BPP_OR       0x16
163 #define BPP_IR       0x17
164 #define BPP_ICR      0x18
165 #define BPP_SIZE     0x1A
166 
167 /* BPP_CSR.  Bits of type RW1 are cleared with writting '1'. */
168 #define P_DEV_ID_MASK   0xf0000000      /* R   */
169 #define P_DEV_ID_ZEBRA  0x40000000
170 #define P_DEV_ID_L64854 0xa0000000      /*      == NCR 89C100+89C105. Pity. */
171 #define P_NA_LOADED     0x08000000      /* R    NA wirtten but was not used */
172 #define P_A_LOADED      0x04000000      /* R    */
173 #define P_DMA_ON        0x02000000      /* R    DMA is not disabled */
174 #define P_EN_NEXT       0x01000000      /* RW   */
175 #define P_TCI_DIS       0x00800000      /* RW   TCI forbidden from interrupts */
176 #define P_DIAG          0x00100000      /* RW   Disables draining and resetting
177                                                 of P-FIFO on loading of P_ADDR*/
178 #define P_BURST_SIZE    0x000c0000      /* RW   SBus burst size */
179 #define P_BURST_8       0x00000000
180 #define P_BURST_4       0x00040000
181 #define P_BURST_1       0x00080000      /*      "No burst" write */
182 #define P_TC            0x00004000      /* RW1  Term Count, can be cleared when
183                                            P_EN_NEXT=1 */
184 #define P_EN_CNT        0x00002000      /* RW   */
185 #define P_EN_DMA        0x00000200      /* RW   */
186 #define P_WRITE         0x00000100      /* R    DMA dir, 1=to ram, 0=to port */
187 #define P_RESET         0x00000080      /* RW   */
188 #define P_SLAVE_ERR     0x00000040      /* RW1  Access size error */
189 #define P_INVALIDATE    0x00000020      /* W    Drop P-FIFO */
190 #define P_INT_EN        0x00000010      /* RW   OK to P_INT_PEND||P_ERR_PEND */
191 #define P_DRAINING      0x0000000c      /* R    P-FIFO is draining to memory */
192 #define P_ERR_PEND      0x00000002      /* R    */
193 #define P_INT_PEND      0x00000001      /* R    */
194 
195 /* BPP_HCR. Time is in increments of SBus clock. */
196 #define P_HCR_TEST      0x8000      /* Allows buried counters to be read */
197 #define P_HCR_DSW       0x7f00      /* Data strobe width (in ticks) */
198 #define P_HCR_DDS       0x007f      /* Data setup before strobe (in ticks) */
199 
200 /* BPP_OCR. */
201 #define P_OCR_MEM_CLR   0x8000
202 #define P_OCR_DATA_SRC  0x4000      /* )                  */
203 #define P_OCR_DS_DSEL   0x2000      /* )  Bidirectional      */
204 #define P_OCR_BUSY_DSEL 0x1000      /* )    selects            */
205 #define P_OCR_ACK_DSEL  0x0800      /* )                  */
206 #define P_OCR_EN_DIAG   0x0400
207 #define P_OCR_BUSY_OP   0x0200      /* Busy operation */
208 #define P_OCR_ACK_OP    0x0100      /* Ack operation */
209 #define P_OCR_SRST      0x0080      /* Reset state machines. Not selfcleaning. */
210 #define P_OCR_IDLE      0x0008      /* PP data transfer state machine is idle */
211 #define P_OCR_V_ILCK    0x0002      /* Versatec faded. Zebra only. */
212 #define P_OCR_EN_VER    0x0001      /* Enable Versatec (0 - enable). Zebra only. */
213 
214 /* BPP_TCR */
215 #define P_TCR_DIR       0x08
216 #define P_TCR_BUSY      0x04
217 #define P_TCR_ACK       0x02
218 #define P_TCR_DS        0x01        /* Strobe */
219 
220 /* BPP_OR */
221 #define P_OR_V3         0x20        /* )                 */
222 #define P_OR_V2         0x10        /* ) on Zebra only   */
223 #define P_OR_V1         0x08        /* )                 */
224 #define P_OR_INIT       0x04
225 #define P_OR_AFXN       0x02        /* Auto Feed */
226 #define P_OR_SLCT_IN    0x01
227 
228 /* BPP_IR */
229 #define P_IR_PE         0x04
230 #define P_IR_SLCT       0x02
231 #define P_IR_ERR        0x01
232 
233 /* BPP_ICR */
234 #define P_DS_IRQ        0x8000      /* RW1  */
235 #define P_ACK_IRQ       0x4000      /* RW1  */
236 #define P_BUSY_IRQ      0x2000      /* RW1  */
237 #define P_PE_IRQ        0x1000      /* RW1  */
238 #define P_SLCT_IRQ      0x0800      /* RW1  */
239 #define P_ERR_IRQ       0x0400      /* RW1  */
240 #define P_DS_IRQ_EN     0x0200      /* RW   Always on rising edge */
241 #define P_ACK_IRQ_EN    0x0100      /* RW   Always on rising edge */
242 #define P_BUSY_IRP      0x0080      /* RW   1= rising edge */
243 #define P_BUSY_IRQ_EN   0x0040      /* RW   */
244 #define P_PE_IRP        0x0020      /* RW   1= rising edge */
245 #define P_PE_IRQ_EN     0x0010      /* RW   */
246 #define P_SLCT_IRP      0x0008      /* RW   1= rising edge */
247 #define P_SLCT_IRQ_EN   0x0004      /* RW   */
248 #define P_ERR_IRP       0x0002      /* RW1  1= rising edge */
249 #define P_ERR_IRQ_EN    0x0001      /* RW   */
250 
251 unsigned long base_addrs[BPP_NO];
252 
253 #define bpp_outb_p(data, base)	sbus_writeb(data, (base) + BPP_DR)
254 #define bpp_inb_p(base)		sbus_readb((base) + BPP_DR)
255 #define bpp_inb(base)		sbus_readb((base) + BPP_DR)
256 
set_pins(unsigned short pins,unsigned minor)257 static void set_pins(unsigned short pins, unsigned minor)
258 {
259       unsigned long base = base_addrs[minor];
260       unsigned char bits_tcr = 0, bits_or = 0;
261 
262       if (instances[minor].direction & 0x20) bits_tcr |= P_TCR_DIR;
263       if (   pins & BPP_PP_nStrobe)          bits_tcr |= P_TCR_DS;
264 
265       if (   pins & BPP_PP_nAutoFd)          bits_or |= P_OR_AFXN;
266       if (! (pins & BPP_PP_nInit))           bits_or |= P_OR_INIT;
267       if (! (pins & BPP_PP_nSelectIn))       bits_or |= P_OR_SLCT_IN;
268 
269       sbus_writeb(bits_or, base + BPP_OR);
270       sbus_writeb(bits_tcr, base + BPP_TCR);
271 }
272 
273 /*
274  * i386 people read output pins from a software image.
275  * We may get them back from hardware.
276  * Again, inversion of pins must he buried here.
277  */
get_pins(unsigned minor)278 static unsigned short get_pins(unsigned minor)
279 {
280       unsigned long base = base_addrs[minor];
281       unsigned short bits = 0;
282       unsigned value_tcr = sbus_readb(base + BPP_TCR);
283       unsigned value_ir = sbus_readb(base + BPP_IR);
284       unsigned value_or = sbus_readb(base + BPP_OR);
285 
286       if (value_tcr & P_TCR_DS)         bits |= BPP_PP_nStrobe;
287       if (value_or & P_OR_AFXN)         bits |= BPP_PP_nAutoFd;
288       if (! (value_or & P_OR_INIT))     bits |= BPP_PP_nInit;
289       if (! (value_or & P_OR_SLCT_IN))  bits |= BPP_PP_nSelectIn;
290 
291       if (value_ir & P_IR_ERR)          bits |= BPP_GP_nFault;
292       if (! (value_ir & P_IR_SLCT))     bits |= BPP_GP_Select;
293       if (! (value_ir & P_IR_PE))       bits |= BPP_GP_PError;
294       if (! (value_tcr & P_TCR_ACK))    bits |= BPP_GP_nAck;
295       if (value_tcr & P_TCR_BUSY)       bits |= BPP_GP_Busy;
296 
297       return bits;
298 }
299 
300 #endif /* __sparc__ */
301 
bpp_wake_up(unsigned long val)302 static void bpp_wake_up(unsigned long val)
303 { wake_up(&instances[val].wait_queue); }
304 
snooze(unsigned long snooze_time,unsigned minor)305 static void snooze(unsigned long snooze_time, unsigned minor)
306 {
307       instances[minor].timer_list.expires = jiffies + snooze_time + 1;
308       instances[minor].timer_list.data    = minor;
309       add_timer(&instances[minor].timer_list);
310       sleep_on (&instances[minor].wait_queue);
311 }
312 
wait_for(unsigned short set,unsigned short clr,unsigned long delay,unsigned minor)313 static int wait_for(unsigned short set, unsigned short clr,
314                unsigned long delay, unsigned minor)
315 {
316       unsigned short pins = get_pins(minor);
317 
318       unsigned long extime = 0;
319 
320       /*
321        * Try a real fast scan for the first jiffy, in case the device
322        * responds real good. The first while loop guesses an expire
323        * time accounting for possible wraparound of jiffies.
324        */
325       while (time_after_eq(jiffies, extime)) extime = jiffies + 1;
326       while ( (time_before(jiffies, extime))
327               && (((pins & set) != set) || ((pins & clr) != 0)) ) {
328             pins = get_pins(minor);
329       }
330 
331       delay -= 1;
332 
333       /*
334        * If my delay expired or the pins are still not where I want
335        * them, then resort to using the timer and greatly reduce my
336        * sample rate. If the peripheral is going to be slow, this will
337        * give the CPU up to some more worthy process.
338        */
339       while ( delay && (((pins & set) != set) || ((pins & clr) != 0)) ) {
340 
341             snooze(1, minor);
342             pins = get_pins(minor);
343             delay -= 1;
344       }
345 
346       if (delay == 0) return -1;
347       else return pins;
348 }
349 
350 /*
351  * Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
352  * errno means something broke, and I do not yet know how to fix it.
353  */
negotiate(unsigned char mode,unsigned minor)354 static int negotiate(unsigned char mode, unsigned minor)
355 {
356       int rc;
357       unsigned short pins = get_pins(minor);
358       if (pins & BPP_PP_nSelectIn) return -EIO;
359 
360 
361         /* Event 0: Write the mode to the data lines */
362       bpp_outb_p(mode, base_addrs[minor]);
363 
364       snooze(TIME_PSetup, minor);
365 
366         /* Event 1: Strobe the mode code into the peripheral */
367       set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);
368 
369         /* Wait for Event 2: Peripheral responds as a 1284 device. */
370       rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
371                 BPP_GP_nAck,
372                 TIME_PResponse,
373                 minor);
374 
375       if (rc == -1) return -ETIMEDOUT;
376 
377         /* Event 3: latch extensibility request */
378       set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);
379 
380         /* ... quick nap while peripheral ponders the byte i'm sending...*/
381       snooze(1, minor);
382 
383         /* Event 4: restore strobe, to ACK peripheral's response. */
384       set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
385 
386         /* Wait for Event 6: Peripheral latches response bits */
387       rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
388       if (rc == -1) return -EIO;
389 
390         /* A 1284 device cannot refuse nibble mode */
391       if (mode == DEFAULT_NIBBLE) return 0;
392 
393       if (pins & BPP_GP_Select) return 0;
394 
395       return -EPROTONOSUPPORT;
396 }
397 
terminate(unsigned minor)398 static int terminate(unsigned minor)
399 {
400       int rc;
401 
402         /* Event 22: Request termination of 1284 mode */
403       set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
404 
405         /* Wait for Events 23 and 24: ACK termination request. */
406       rc = wait_for(BPP_GP_Busy|BPP_GP_nFault,
407                 BPP_GP_nAck,
408                 TIME_PSetup+TIME_PResponse,
409                 minor);
410 
411       instances[minor].direction = 0;
412       instances[minor].mode = COMPATIBILITY;
413 
414       if (rc == -1) {
415           return -EIO;
416       }
417 
418         /* Event 25: Handshake by lowering nAutoFd */
419       set_pins(BPP_PP_nStrobe|BPP_PP_nInit, minor);
420 
421         /* Event 26: Peripheral wiggles lines... */
422 
423         /* Event 27: Peripheral sets nAck HIGH to ack handshake */
424       rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
425       if (rc == -1) {
426           set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
427           return -EIO;
428       }
429 
430         /* Event 28: Finish phase by raising nAutoFd */
431       set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
432 
433       return 0;
434 }
435 
436 static spinlock_t bpp_open_lock = SPIN_LOCK_UNLOCKED;
437 
438 /*
439  * Allow only one process to open the device at a time.
440  */
bpp_open(struct inode * inode,struct file * f)441 static int bpp_open(struct inode *inode, struct file *f)
442 {
443       unsigned minor = MINOR(inode->i_rdev);
444       int ret;
445 
446       spin_lock(&bpp_open_lock);
447       ret = 0;
448       if (minor >= BPP_NO) {
449 	      ret = -ENODEV;
450       } else {
451 	      if (! instances[minor].present) {
452 		      ret = -ENODEV;
453 	      } else {
454 		      if (instances[minor].opened)
455 			      ret = -EBUSY;
456 		      else
457 			      instances[minor].opened = 1;
458 	      }
459       }
460       spin_unlock(&bpp_open_lock);
461 
462       return ret;
463 }
464 
465 /*
466  * When the process closes the device, this method is called to clean
467  * up and reset the hardware. Always leave the device in compatibility
468  * mode as this is a reasonable place to clean up from messes made by
469  * ioctls, or other mayhem.
470  */
bpp_release(struct inode * inode,struct file * f)471 static int bpp_release(struct inode *inode, struct file *f)
472 {
473       unsigned minor = MINOR(inode->i_rdev);
474 
475       spin_lock(&bpp_open_lock);
476       instances[minor].opened = 0;
477 
478       if (instances[minor].mode != COMPATIBILITY)
479 	      terminate(minor);
480 
481       spin_unlock(&bpp_open_lock);
482 
483       return 0;
484 }
485 
read_nibble(unsigned minor,char * c,unsigned long cnt)486 static long read_nibble(unsigned minor, char *c, unsigned long cnt)
487 {
488       unsigned long remaining = cnt;
489       long rc;
490 
491       while (remaining > 0) {
492           unsigned char byte = 0;
493           int pins;
494 
495           /* Event 7: request nibble */
496           set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
497 
498           /* Wait for event 9: Peripher strobes first nibble */
499           pins = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
500           if (pins == -1) return -ETIMEDOUT;
501 
502           /* Event 10: I handshake nibble */
503           set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
504           if (pins & BPP_GP_nFault) byte |= 0x01;
505           if (pins & BPP_GP_Select) byte |= 0x02;
506           if (pins & BPP_GP_PError) byte |= 0x04;
507           if (pins & BPP_GP_Busy)   byte |= 0x08;
508 
509           /* Wait for event 11: Peripheral handshakes nibble */
510           rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
511 
512           /* Event 7: request nibble */
513           set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
514 
515           /* Wait for event 9: Peripher strobes first nibble */
516           pins = wait_for(0, BPP_GP_nAck, TIME_PResponse, minor);
517           if (rc == -1) return -ETIMEDOUT;
518 
519           /* Event 10: I handshake nibble */
520           set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
521           if (pins & BPP_GP_nFault) byte |= 0x10;
522           if (pins & BPP_GP_Select) byte |= 0x20;
523           if (pins & BPP_GP_PError) byte |= 0x40;
524           if (pins & BPP_GP_Busy)   byte |= 0x80;
525 
526           if (put_user(byte, c))
527 		  return -EFAULT;
528           c += 1;
529           remaining -= 1;
530 
531           /* Wait for event 11: Peripheral handshakes nibble */
532           rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
533           if (rc == -1) return -EIO;
534       }
535 
536       return cnt - remaining;
537 }
538 
read_ecp(unsigned minor,char * c,unsigned long cnt)539 static long read_ecp(unsigned minor, char *c, unsigned long cnt)
540 {
541       unsigned long remaining;
542       long rc;
543 
544         /* Turn ECP mode from forward to reverse if needed. */
545       if (! instances[minor].direction) {
546           unsigned short pins = get_pins(minor);
547 
548             /* Event 38: Turn the bus around */
549           instances[minor].direction = 0x20;
550           pins &= ~BPP_PP_nAutoFd;
551           set_pins(pins, minor);
552 
553             /* Event 39: Set pins for reverse mode. */
554           snooze(TIME_PSetup, minor);
555           set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
556 
557             /* Wait for event 40: Peripheral ready to be strobed */
558           rc = wait_for(0, BPP_GP_PError, TIME_PResponse, minor);
559           if (rc == -1) return -ETIMEDOUT;
560       }
561 
562       remaining = cnt;
563 
564       while (remaining > 0) {
565 
566             /* If there is a run length for a repeated byte, repeat */
567             /* that byte a few times. */
568           if (instances[minor].run_length && !instances[minor].run_flag) {
569 
570               char buffer[128];
571               unsigned idx;
572               unsigned repeat = remaining < instances[minor].run_length
573                                      ? remaining
574                                : instances[minor].run_length;
575 
576               for (idx = 0 ;  idx < repeat ;  idx += 1)
577                 buffer[idx] = instances[minor].repeat_byte;
578 
579               if (copy_to_user(c, buffer, repeat))
580 		      return -EFAULT;
581               remaining -= repeat;
582               c += repeat;
583               instances[minor].run_length -= repeat;
584           }
585 
586           if (remaining == 0) break;
587 
588 
589             /* Wait for Event 43: Data active on the bus. */
590           rc = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
591           if (rc == -1) break;
592 
593           if (rc & BPP_GP_Busy) {
594                 /* OK, this is data. read it in. */
595               unsigned char byte = bpp_inb(base_addrs[minor]);
596               if (put_user(byte, c))
597 		      return -EFAULT;
598               c += 1;
599               remaining -= 1;
600 
601               if (instances[minor].run_flag) {
602                   instances[minor].repeat_byte = byte;
603                   instances[minor].run_flag = 0;
604               }
605 
606           } else {
607               unsigned char byte = bpp_inb(base_addrs[minor]);
608               if (byte & 0x80) {
609                   printk("bpp%d: "
610                          "Ignoring ECP channel %u from device.\n",
611                          minor, byte & 0x7f);
612               } else {
613                   instances[minor].run_length = byte;
614                   instances[minor].run_flag = 1;
615               }
616           }
617 
618             /* Event 44: I got it. */
619           set_pins(BPP_PP_nStrobe|BPP_PP_nAutoFd|BPP_PP_nSelectIn, minor);
620 
621             /* Wait for event 45: peripheral handshake */
622           rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
623           if (rc == -1) return -ETIMEDOUT;
624 
625              /* Event 46: Finish handshake */
626           set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
627 
628       }
629 
630 
631       return cnt - remaining;
632 }
633 
bpp_read(struct file * f,char * c,size_t cnt,loff_t * ppos)634 static ssize_t bpp_read(struct file *f, char *c, size_t cnt, loff_t * ppos)
635 {
636       long rc;
637       const unsigned minor = MINOR(f->f_dentry->d_inode->i_rdev);
638       if (minor >= BPP_NO) return -ENODEV;
639       if (!instances[minor].present) return -ENODEV;
640 
641       switch (instances[minor].mode) {
642 
643         default:
644           if (instances[minor].mode != COMPATIBILITY)
645             terminate(minor);
646 
647           if (instances[minor].enhanced) {
648               /* For now, do all reads with ECP-RLE mode */
649               unsigned short pins;
650 
651               rc = negotiate(DEFAULT_ECP, minor);
652               if (rc < 0) break;
653 
654               instances[minor].mode = ECP_RLE;
655 
656               /* Event 30: set nAutoFd low to setup for ECP mode */
657               pins = get_pins(minor);
658               pins &= ~BPP_PP_nAutoFd;
659               set_pins(pins, minor);
660 
661               /* Wait for Event 31: peripheral ready */
662               rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
663               if (rc == -1) return -ETIMEDOUT;
664 
665               rc = read_ecp(minor, c, cnt);
666 
667           } else {
668               rc = negotiate(DEFAULT_NIBBLE, minor);
669               if (rc < 0) break;
670 
671               instances[minor].mode = NIBBLE;
672 
673               rc = read_nibble(minor, c, cnt);
674           }
675           break;
676 
677         case NIBBLE:
678           rc = read_nibble(minor, c, cnt);
679           break;
680 
681         case ECP:
682         case ECP_RLE:
683           rc = read_ecp(minor, c, cnt);
684           break;
685 
686       }
687 
688 
689       return rc;
690 }
691 
692 /*
693  * Compatibility mode handshaking is a matter of writing data,
694  * strobing it, and waiting for the printer to stop being busy.
695  */
write_compat(unsigned minor,const char * c,unsigned long cnt)696 static long write_compat(unsigned minor, const char *c, unsigned long cnt)
697 {
698       long rc;
699       unsigned short pins = get_pins(minor);
700 
701       unsigned long remaining = cnt;
702 
703 
704       while (remaining > 0) {
705             unsigned char byte;
706 
707             if (get_user(byte, c))
708 		    return -EFAULT;
709             c += 1;
710 
711             rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
712             if (rc == -1) return -ETIMEDOUT;
713 
714             bpp_outb_p(byte, base_addrs[minor]);
715             remaining -= 1;
716           /* snooze(1, minor); */
717 
718           pins &= ~BPP_PP_nStrobe;
719           set_pins(pins, minor);
720 
721           rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
722 
723           pins |= BPP_PP_nStrobe;
724           set_pins(pins, minor);
725       }
726 
727       return cnt - remaining;
728 }
729 
730 /*
731  * Write data using ECP mode. Watch out that the port may be set up
732  * for reading. If so, turn the port around.
733  */
write_ecp(unsigned minor,const char * c,unsigned long cnt)734 static long write_ecp(unsigned minor, const char *c, unsigned long cnt)
735 {
736       unsigned short pins = get_pins(minor);
737       unsigned long remaining = cnt;
738 
739       if (instances[minor].direction) {
740           int rc;
741 
742             /* Event 47 Request bus be turned around */
743           pins |= BPP_PP_nInit;
744           set_pins(pins, minor);
745 
746             /* Wait for Event 49: Peripheral relinquished bus */
747           rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
748 
749           pins |= BPP_PP_nAutoFd;
750           instances[minor].direction = 0;
751           set_pins(pins, minor);
752       }
753 
754       while (remaining > 0) {
755           unsigned char byte;
756           int rc;
757 
758           if (get_user(byte, c))
759 		  return -EFAULT;
760 
761           rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
762           if (rc == -1) return -ETIMEDOUT;
763 
764           c += 1;
765 
766           bpp_outb_p(byte, base_addrs[minor]);
767 
768           pins &= ~BPP_PP_nStrobe;
769           set_pins(pins, minor);
770 
771           pins |= BPP_PP_nStrobe;
772           rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
773           if (rc == -1) return -EIO;
774 
775           set_pins(pins, minor);
776       }
777 
778       return cnt - remaining;
779 }
780 
781 /*
782  * Write to the peripheral. Be sensitive of the current mode. If I'm
783  * in a mode that can be turned around (ECP) then just do
784  * that. Otherwise, terminate and do my writing in compat mode. This
785  * is the safest course as any device can handle it.
786  */
bpp_write(struct file * f,const char * c,size_t cnt,loff_t * ppos)787 static ssize_t bpp_write(struct file *f, const char *c, size_t cnt, loff_t * ppos)
788 {
789       long errno = 0;
790       const unsigned minor = MINOR(f->f_dentry->d_inode->i_rdev);
791       if (minor >= BPP_NO) return -ENODEV;
792       if (!instances[minor].present) return -ENODEV;
793 
794       switch (instances[minor].mode) {
795 
796         case ECP:
797         case ECP_RLE:
798           errno = write_ecp(minor, c, cnt);
799           break;
800         case COMPATIBILITY:
801           errno = write_compat(minor, c, cnt);
802           break;
803         default:
804           terminate(minor);
805           errno = write_compat(minor, c, cnt);
806       }
807 
808       return errno;
809 }
810 
bpp_ioctl(struct inode * inode,struct file * f,unsigned int cmd,unsigned long arg)811 static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
812 		 unsigned long arg)
813 {
814       int errno = 0;
815 
816       unsigned minor = MINOR(inode->i_rdev);
817       if (minor >= BPP_NO) return -ENODEV;
818       if (!instances[minor].present) return -ENODEV;
819 
820 
821       switch (cmd) {
822 
823         case BPP_PUT_PINS:
824           set_pins(arg, minor);
825           break;
826 
827         case BPP_GET_PINS:
828           errno = get_pins(minor);
829           break;
830 
831         case BPP_PUT_DATA:
832           bpp_outb_p(arg, base_addrs[minor]);
833           break;
834 
835         case BPP_GET_DATA:
836           errno = bpp_inb_p(base_addrs[minor]);
837           break;
838 
839         case BPP_SET_INPUT:
840           if (arg)
841             if (instances[minor].enhanced) {
842                 unsigned short bits = get_pins(minor);
843                 instances[minor].direction = 0x20;
844                 set_pins(bits, minor);
845             } else {
846                 errno = -ENOTTY;
847             }
848           else {
849               unsigned short bits = get_pins(minor);
850               instances[minor].direction = 0x00;
851               set_pins(bits, minor);
852           }
853           break;
854 
855         default:
856             errno = -EINVAL;
857       }
858 
859       return errno;
860 }
861 
862 static struct file_operations bpp_fops = {
863 	owner:		THIS_MODULE,
864 	read:		bpp_read,
865 	write:		bpp_write,
866 	ioctl:		bpp_ioctl,
867 	open:		bpp_open,
868 	release:	bpp_release,
869 };
870 
871 #if defined(__i386__)
872 
873 #define collectLptPorts()  {}
874 
probeLptPort(unsigned idx)875 static void probeLptPort(unsigned idx)
876 {
877       unsigned int testvalue;
878       const unsigned short lpAddr = base_addrs[idx];
879 
880       instances[idx].present = 0;
881       instances[idx].enhanced = 0;
882       instances[idx].direction = 0;
883       instances[idx].mode = COMPATIBILITY;
884       instances[idx].wait_queue = 0;
885       instances[idx].run_length = 0;
886       instances[idx].run_flag = 0;
887       init_timer(&instances[idx].timer_list);
888       instances[idx].timer_list.function = bpp_wake_up;
889       if (check_region(lpAddr,3)) return;
890 
891       /*
892        * First, make sure the instance exists. Do this by writing to
893        * the data latch and reading the value back. If the port *is*
894        * present, test to see if it supports extended-mode
895        * operation. This will be required for IEEE1284 reverse
896        * transfers.
897        */
898 
899       outb_p(BPP_PROBE_CODE, lpAddr);
900       for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
901             ;
902       testvalue = inb_p(lpAddr);
903       if (testvalue == BPP_PROBE_CODE) {
904             unsigned save;
905             instances[idx].present = 1;
906 
907             request_region(lpAddr,3, dev_name);
908             save = inb_p(lpAddr+2);
909             for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
910                   ;
911             outb_p(save|0x20, lpAddr+2);
912             for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
913                   ;
914             outb_p(~BPP_PROBE_CODE, lpAddr);
915             for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
916                   ;
917             testvalue = inb_p(lpAddr);
918             if ((testvalue&0xff) == (0xff&~BPP_PROBE_CODE))
919                   instances[idx].enhanced = 0;
920             else
921                   instances[idx].enhanced = 1;
922             outb_p(save, lpAddr+2);
923       }
924 
925       /*
926        * Leave the port in compat idle mode.
927        */
928       set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
929 
930       printk("bpp%d: Port at 0x%03x: Enhanced mode %s\n", idx, base_addrs[idx],
931             instances[idx].enhanced? "SUPPORTED" : "UNAVAILABLE");
932 }
933 
freeLptPort(int idx)934 static inline void freeLptPort(int idx)
935 {
936       release_region(base_addrs[idx], 3);
937 }
938 
939 #endif
940 
941 #if defined(__sparc__)
942 
map_bpp(struct sbus_dev * dev,int idx)943 static unsigned long map_bpp(struct sbus_dev *dev, int idx)
944 {
945       return sbus_ioremap(&dev->resource[0], 0, BPP_SIZE, "bpp");
946 }
947 
collectLptPorts(void)948 static int collectLptPorts(void)
949 {
950 	struct sbus_bus *bus;
951 	struct sbus_dev *dev;
952 	int count;
953 
954 	count = 0;
955 	for_all_sbusdev(dev, bus) {
956 		if (strcmp(dev->prom_name, "SUNW,bpp") == 0) {
957 			if (count >= BPP_NO) {
958 				printk(KERN_NOTICE
959 				       "bpp: More than %d bpp ports,"
960 				       " rest is ignored\n", BPP_NO);
961 				return count;
962 			}
963 			base_addrs[count] = map_bpp(dev, count);
964 			count++;
965 		}
966 	}
967 	return count;
968 }
969 
probeLptPort(unsigned idx)970 static void probeLptPort(unsigned idx)
971 {
972       unsigned long rp = base_addrs[idx];
973       __u32 csr;
974       char *brand;
975 
976       instances[idx].present = 0;
977       instances[idx].enhanced = 0;
978       instances[idx].direction = 0;
979       instances[idx].mode = COMPATIBILITY;
980       init_waitqueue_head(&instances[idx].wait_queue);
981       instances[idx].run_length = 0;
982       instances[idx].run_flag = 0;
983       init_timer(&instances[idx].timer_list);
984       instances[idx].timer_list.function = bpp_wake_up;
985 
986       if (rp == 0) return;
987 
988       instances[idx].present = 1;
989       instances[idx].enhanced = 1;   /* Sure */
990 
991       csr = sbus_readl(rp + BPP_CSR);
992       if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
993             udelay(20);
994             csr = sbus_readl(rp + BPP_CSR);
995             if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
996                   printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
997             }
998       }
999       printk("bpp%d: reset with 0x%08x ..", idx, csr);
1000       sbus_writel((csr | P_RESET) & ~P_INT_EN, rp + BPP_CSR);
1001       udelay(500);
1002       sbus_writel(sbus_readl(rp + BPP_CSR) & ~P_RESET, rp + BPP_CSR);
1003       csr = sbus_readl(rp + BPP_CSR);
1004       printk(" done with csr=0x%08x ocr=0x%04x\n",
1005          csr, sbus_readw(rp + BPP_OCR));
1006 
1007       switch (csr & P_DEV_ID_MASK) {
1008       case P_DEV_ID_ZEBRA:
1009             brand = "Zebra";
1010             break;
1011       case P_DEV_ID_L64854:
1012             brand = "DMA2";
1013             break;
1014       default:
1015             brand = "Unknown";
1016       }
1017       printk("bpp%d: %s at 0x%lx\n", idx, brand, rp);
1018 
1019       /*
1020        * Leave the port in compat idle mode.
1021        */
1022       set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
1023 
1024       return;
1025 }
1026 
freeLptPort(int idx)1027 static inline void freeLptPort(int idx)
1028 {
1029       sbus_iounmap(base_addrs[idx], BPP_SIZE);
1030 }
1031 
1032 #endif
1033 
1034 static devfs_handle_t devfs_handle;
1035 
bpp_init(void)1036 static int __init bpp_init(void)
1037 {
1038 	int rc;
1039 	unsigned idx;
1040 
1041 	rc = collectLptPorts();
1042 	if (rc == 0)
1043 		return -ENODEV;
1044 
1045 	rc = devfs_register_chrdev(BPP_MAJOR, dev_name, &bpp_fops);
1046 	if (rc < 0)
1047 		return rc;
1048 
1049 	for (idx = 0; idx < BPP_NO; idx += 1) {
1050 		instances[idx].opened = 0;
1051 		probeLptPort(idx);
1052 	}
1053 	devfs_handle = devfs_mk_dir (NULL, "bpp", NULL);
1054 	devfs_register_series (devfs_handle, "%u", BPP_NO, DEVFS_FL_DEFAULT,
1055 			       BPP_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR,
1056 			       &bpp_fops, NULL);
1057 
1058 	return 0;
1059 }
1060 
bpp_cleanup(void)1061 static void __exit bpp_cleanup(void)
1062 {
1063 	unsigned idx;
1064 
1065 	devfs_unregister (devfs_handle);
1066 	devfs_unregister_chrdev(BPP_MAJOR, dev_name);
1067 
1068 	for (idx = 0 ;  idx < BPP_NO ;  idx += 1) {
1069 		if (instances[idx].present)
1070 			freeLptPort(idx);
1071 	}
1072 }
1073 
1074 module_init(bpp_init);
1075 module_exit(bpp_cleanup);
1076 
1077 MODULE_LICENSE("GPL");
1078