1 /*
2 * atari_SCC.h: Definitions for the Am8530 Serial Communications Controller
3 *
4 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 *
10 */
11
12
13 #ifndef _SCC_H
14 #define _SCC_H
15
16 #include <linux/delay.h>
17
18 /* Special configuration ioctls for the Atari SCC5380 Serial
19 * Communications Controller
20 */
21
22 /* ioctl command codes */
23
24 #define TIOCGATSCC 0x54c0 /* get SCC configuration */
25 #define TIOCSATSCC 0x54c1 /* set SCC configuration */
26 #define TIOCDATSCC 0x54c2 /* reset configuration to defaults */
27
28 /* Clock sources */
29
30 #define CLK_RTxC 0
31 #define CLK_TRxC 1
32 #define CLK_PCLK 2
33
34 /* baud_bases for the common clocks in the Atari. These are the real
35 * frequencies divided by 16.
36 */
37
38 #define SCC_BAUD_BASE_TIMC 19200 /* 0.3072 MHz from TT-MFP, Timer C */
39 #define SCC_BAUD_BASE_BCLK 153600 /* 2.4576 MHz */
40 #define SCC_BAUD_BASE_PCLK4 229500 /* 3.6720 MHz */
41 #define SCC_BAUD_BASE_PCLK 503374 /* 8.0539763 MHz */
42 #define SCC_BAUD_BASE_NONE 0 /* for not connected or unused
43 * clock sources */
44
45 /* The SCC clock configuration structure */
46
47 struct scc_clock_config {
48 unsigned RTxC_base; /* base_baud of RTxC */
49 unsigned TRxC_base; /* base_baud of TRxC */
50 unsigned PCLK_base; /* base_baud of PCLK, both channels! */
51 struct {
52 unsigned clksrc; /* CLK_RTxC, CLK_TRxC or CLK_PCLK */
53 unsigned divisor; /* divisor for base baud, valid values:
54 * see below */
55 } baud_table[17]; /* For 50, 75, 110, 135, 150, 200, 300,
56 * 600, 1200, 1800, 2400, 4800, 9600,
57 * 19200, 38400, 57600 and 115200 bps.
58 * The last two could be replaced by
59 * other rates > 38400 if they're not
60 * possible.
61 */
62 };
63
64 /* The following divisors are valid:
65 *
66 * - CLK_RTxC: 1 or even (1, 2 and 4 are the direct modes, > 4 use
67 * the BRG)
68 *
69 * - CLK_TRxC: 1, 2 or 4 (no BRG, only direct modes possible)
70 *
71 * - CLK_PCLK: >= 4 and even (no direct modes, only BRG)
72 *
73 */
74
75 struct scc_port {
76 struct gs_port gs;
77 volatile unsigned char *ctrlp;
78 volatile unsigned char *datap;
79 int x_char; /* xon/xoff character */
80 int c_dcd;
81 int channel;
82 struct scc_port *port_a; /* Reference to port A and B */
83 struct scc_port *port_b; /* structs for reg access */
84 };
85
86 #define SCC_MAGIC 0x52696368
87
88 /***********************************************************************/
89 /* */
90 /* Register Names */
91 /* */
92 /***********************************************************************/
93
94 /* The SCC documentation gives no explicit names to the registers,
95 * they're just called WR0..15 and RR0..15. To make the source code
96 * better readable and make the transparent write reg read access (see
97 * below) possible, I christen them here with self-invented names.
98 * Note that (real) read registers are assigned numbers 16..31. WR7'
99 * has number 33.
100 */
101
102 #define COMMAND_REG 0 /* wo */
103 #define INT_AND_DMA_REG 1 /* wo */
104 #define INT_VECTOR_REG 2 /* rw, common to both channels */
105 #define RX_CTRL_REG 3 /* rw */
106 #define AUX1_CTRL_REG 4 /* rw */
107 #define TX_CTRL_REG 5 /* rw */
108 #define SYNC_ADR_REG 6 /* wo */
109 #define SYNC_CHAR_REG 7 /* wo */
110 #define SDLC_OPTION_REG 33 /* wo */
111 #define TX_DATA_REG 8 /* wo */
112 #define MASTER_INT_CTRL 9 /* wo, common to both channels */
113 #define AUX2_CTRL_REG 10 /* rw */
114 #define CLK_CTRL_REG 11 /* wo */
115 #define TIMER_LOW_REG 12 /* rw */
116 #define TIMER_HIGH_REG 13 /* rw */
117 #define DPLL_CTRL_REG 14 /* wo */
118 #define INT_CTRL_REG 15 /* rw */
119
120 #define STATUS_REG 16 /* ro */
121 #define SPCOND_STATUS_REG 17 /* wo */
122 /* RR2 is WR2 for Channel A, Channel B gives vector + current status: */
123 #define CURR_VECTOR_REG 18 /* Ch. B only, Ch. A for rw */
124 #define INT_PENDING_REG 19 /* Channel A only! */
125 /* RR4 is WR4, if b6(MR7') == 1 */
126 /* RR5 is WR5, if b6(MR7') == 1 */
127 #define FS_FIFO_LOW_REG 22 /* ro */
128 #define FS_FIFO_HIGH_REG 23 /* ro */
129 #define RX_DATA_REG 24 /* ro */
130 /* RR9 is WR3, if b6(MR7') == 1 */
131 #define DPLL_STATUS_REG 26 /* ro */
132 /* RR11 is WR10, if b6(MR7') == 1 */
133 /* RR12 is WR12 */
134 /* RR13 is WR13 */
135 /* RR14 not present */
136 /* RR15 is WR15 */
137
138
139 /***********************************************************************/
140 /* */
141 /* Register Values */
142 /* */
143 /***********************************************************************/
144
145
146 /* WR0: COMMAND_REG "CR" */
147
148 #define CR_RX_CRC_RESET 0x40
149 #define CR_TX_CRC_RESET 0x80
150 #define CR_TX_UNDERRUN_RESET 0xc0
151
152 #define CR_EXTSTAT_RESET 0x10
153 #define CR_SEND_ABORT 0x18
154 #define CR_ENAB_INT_NEXT_RX 0x20
155 #define CR_TX_PENDING_RESET 0x28
156 #define CR_ERROR_RESET 0x30
157 #define CR_HIGHEST_IUS_RESET 0x38
158
159
160 /* WR1: INT_AND_DMA_REG "IDR" */
161
162 #define IDR_EXTSTAT_INT_ENAB 0x01
163 #define IDR_TX_INT_ENAB 0x02
164 #define IDR_PARERR_AS_SPCOND 0x04
165
166 #define IDR_RX_INT_DISAB 0x00
167 #define IDR_RX_INT_FIRST 0x08
168 #define IDR_RX_INT_ALL 0x10
169 #define IDR_RX_INT_SPCOND 0x18
170 #define IDR_RX_INT_MASK 0x18
171
172 #define IDR_WAITREQ_RX 0x20
173 #define IDR_WAITREQ_IS_REQ 0x40
174 #define IDR_WAITREQ_ENAB 0x80
175
176
177 /* WR3: RX_CTRL_REG "RCR" */
178
179 #define RCR_RX_ENAB 0x01
180 #define RCR_DISCARD_SYNC_CHARS 0x02
181 #define RCR_ADDR_SEARCH 0x04
182 #define RCR_CRC_ENAB 0x08
183 #define RCR_SEARCH_MODE 0x10
184 #define RCR_AUTO_ENAB_MODE 0x20
185
186 #define RCR_CHSIZE_MASK 0xc0
187 #define RCR_CHSIZE_5 0x00
188 #define RCR_CHSIZE_6 0x40
189 #define RCR_CHSIZE_7 0x80
190 #define RCR_CHSIZE_8 0xc0
191
192
193 /* WR4: AUX1_CTRL_REG "A1CR" */
194
195 #define A1CR_PARITY_MASK 0x03
196 #define A1CR_PARITY_NONE 0x00
197 #define A1CR_PARITY_ODD 0x01
198 #define A1CR_PARITY_EVEN 0x03
199
200 #define A1CR_MODE_MASK 0x0c
201 #define A1CR_MODE_SYNCR 0x00
202 #define A1CR_MODE_ASYNC_1 0x04
203 #define A1CR_MODE_ASYNC_15 0x08
204 #define A1CR_MODE_ASYNC_2 0x0c
205
206 #define A1CR_SYNCR_MODE_MASK 0x30
207 #define A1CR_SYNCR_MONOSYNC 0x00
208 #define A1CR_SYNCR_BISYNC 0x10
209 #define A1CR_SYNCR_SDLC 0x20
210 #define A1CR_SYNCR_EXTCSYNC 0x30
211
212 #define A1CR_CLKMODE_MASK 0xc0
213 #define A1CR_CLKMODE_x1 0x00
214 #define A1CR_CLKMODE_x16 0x40
215 #define A1CR_CLKMODE_x32 0x80
216 #define A1CR_CLKMODE_x64 0xc0
217
218
219 /* WR5: TX_CTRL_REG "TCR" */
220
221 #define TCR_TX_CRC_ENAB 0x01
222 #define TCR_RTS 0x02
223 #define TCR_USE_CRC_CCITT 0x00
224 #define TCR_USE_CRC_16 0x04
225 #define TCR_TX_ENAB 0x08
226 #define TCR_SEND_BREAK 0x10
227
228 #define TCR_CHSIZE_MASK 0x60
229 #define TCR_CHSIZE_5 0x00
230 #define TCR_CHSIZE_6 0x20
231 #define TCR_CHSIZE_7 0x40
232 #define TCR_CHSIZE_8 0x60
233
234 #define TCR_DTR 0x80
235
236
237 /* WR7': SLDC_OPTION_REG "SOR" */
238
239 #define SOR_AUTO_TX_ENAB 0x01
240 #define SOR_AUTO_EOM_RESET 0x02
241 #define SOR_AUTO_RTS_MODE 0x04
242 #define SOR_NRZI_DISAB_HIGH 0x08
243 #define SOR_ALT_DTRREQ_TIMING 0x10
244 #define SOR_READ_CRC_CHARS 0x20
245 #define SOR_EXTENDED_REG_ACCESS 0x40
246
247
248 /* WR9: MASTER_INT_CTRL "MIC" */
249
250 #define MIC_VEC_INCL_STAT 0x01
251 #define MIC_NO_VECTOR 0x02
252 #define MIC_DISAB_LOWER_CHAIN 0x04
253 #define MIC_MASTER_INT_ENAB 0x08
254 #define MIC_STATUS_HIGH 0x10
255 #define MIC_IGN_INTACK 0x20
256
257 #define MIC_NO_RESET 0x00
258 #define MIC_CH_A_RESET 0x40
259 #define MIC_CH_B_RESET 0x80
260 #define MIC_HARD_RESET 0xc0
261
262
263 /* WR10: AUX2_CTRL_REG "A2CR" */
264
265 #define A2CR_SYNC_6 0x01
266 #define A2CR_LOOP_MODE 0x02
267 #define A2CR_ABORT_ON_UNDERRUN 0x04
268 #define A2CR_MARK_IDLE 0x08
269 #define A2CR_GO_ACTIVE_ON_POLL 0x10
270
271 #define A2CR_CODING_MASK 0x60
272 #define A2CR_CODING_NRZ 0x00
273 #define A2CR_CODING_NRZI 0x20
274 #define A2CR_CODING_FM1 0x40
275 #define A2CR_CODING_FM0 0x60
276
277 #define A2CR_PRESET_CRC_1 0x80
278
279
280 /* WR11: CLK_CTRL_REG "CCR" */
281
282 #define CCR_TRxCOUT_MASK 0x03
283 #define CCR_TRxCOUT_XTAL 0x00
284 #define CCR_TRxCOUT_TXCLK 0x01
285 #define CCR_TRxCOUT_BRG 0x02
286 #define CCR_TRxCOUT_DPLL 0x03
287
288 #define CCR_TRxC_OUTPUT 0x04
289
290 #define CCR_TXCLK_MASK 0x18
291 #define CCR_TXCLK_RTxC 0x00
292 #define CCR_TXCLK_TRxC 0x08
293 #define CCR_TXCLK_BRG 0x10
294 #define CCR_TXCLK_DPLL 0x18
295
296 #define CCR_RXCLK_MASK 0x60
297 #define CCR_RXCLK_RTxC 0x00
298 #define CCR_RXCLK_TRxC 0x20
299 #define CCR_RXCLK_BRG 0x40
300 #define CCR_RXCLK_DPLL 0x60
301
302 #define CCR_RTxC_XTAL 0x80
303
304
305 /* WR14: DPLL_CTRL_REG "DCR" */
306
307 #define DCR_BRG_ENAB 0x01
308 #define DCR_BRG_USE_PCLK 0x02
309 #define DCR_DTRREQ_IS_REQ 0x04
310 #define DCR_AUTO_ECHO 0x08
311 #define DCR_LOCAL_LOOPBACK 0x10
312
313 #define DCR_DPLL_EDGE_SEARCH 0x20
314 #define DCR_DPLL_ERR_RESET 0x40
315 #define DCR_DPLL_DISAB 0x60
316 #define DCR_DPLL_CLK_BRG 0x80
317 #define DCR_DPLL_CLK_RTxC 0xa0
318 #define DCR_DPLL_FM 0xc0
319 #define DCR_DPLL_NRZI 0xe0
320
321
322 /* WR15: INT_CTRL_REG "ICR" */
323
324 #define ICR_OPTIONREG_SELECT 0x01
325 #define ICR_ENAB_BRG_ZERO_INT 0x02
326 #define ICR_USE_FS_FIFO 0x04
327 #define ICR_ENAB_DCD_INT 0x08
328 #define ICR_ENAB_SYNC_INT 0x10
329 #define ICR_ENAB_CTS_INT 0x20
330 #define ICR_ENAB_UNDERRUN_INT 0x40
331 #define ICR_ENAB_BREAK_INT 0x80
332
333
334 /* RR0: STATUS_REG "SR" */
335
336 #define SR_CHAR_AVAIL 0x01
337 #define SR_BRG_ZERO 0x02
338 #define SR_TX_BUF_EMPTY 0x04
339 #define SR_DCD 0x08
340 #define SR_SYNC_ABORT 0x10
341 #define SR_CTS 0x20
342 #define SR_TX_UNDERRUN 0x40
343 #define SR_BREAK 0x80
344
345
346 /* RR1: SPCOND_STATUS_REG "SCSR" */
347
348 #define SCSR_ALL_SENT 0x01
349 #define SCSR_RESIDUAL_MASK 0x0e
350 #define SCSR_PARITY_ERR 0x10
351 #define SCSR_RX_OVERRUN 0x20
352 #define SCSR_CRC_FRAME_ERR 0x40
353 #define SCSR_END_OF_FRAME 0x80
354
355
356 /* RR3: INT_PENDING_REG "IPR" */
357
358 #define IPR_B_EXTSTAT 0x01
359 #define IPR_B_TX 0x02
360 #define IPR_B_RX 0x04
361 #define IPR_A_EXTSTAT 0x08
362 #define IPR_A_TX 0x10
363 #define IPR_A_RX 0x20
364
365
366 /* RR7: FS_FIFO_HIGH_REG "FFHR" */
367
368 #define FFHR_CNT_MASK 0x3f
369 #define FFHR_IS_FROM_FIFO 0x40
370 #define FFHR_FIFO_OVERRUN 0x80
371
372
373 /* RR10: DPLL_STATUS_REG "DSR" */
374
375 #define DSR_ON_LOOP 0x02
376 #define DSR_ON_LOOP_SENDING 0x10
377 #define DSR_TWO_CLK_MISSING 0x40
378 #define DSR_ONE_CLK_MISSING 0x80
379
380 /***********************************************************************/
381 /* */
382 /* Register Access */
383 /* */
384 /***********************************************************************/
385
386
387 /* The SCC needs 3.5 PCLK cycles recovery time between to register
388 * accesses. PCLK runs with 8 MHz on an Atari, so this delay is 3.5 *
389 * 125 ns = 437.5 ns. This is too short for udelay().
390 * 10/16/95: A tstb st_mfp.par_dt_reg takes 600ns (sure?) and thus should be
391 * quite right
392 */
393
394 #define scc_reg_delay() \
395 do { \
396 if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147) \
397 __asm__ __volatile__ ( " nop; nop"); \
398 else if (MACH_IS_ATARI) \
399 __asm__ __volatile__ ( "tstb %0" : : "g" (*_scc_del) : "cc" );\
400 } while (0)
401
402 static unsigned char scc_shadow[2][16];
403
404 /* The following functions should relax the somehow complicated
405 * register access of the SCC. _SCCwrite() stores all written values
406 * (except for WR0 and WR8) in shadow registers for later recall. This
407 * removes the burden of remembering written values as needed. The
408 * extra work of storing the value doesn't count, since a delay is
409 * needed after a SCC access anyway. Additionally, _SCCwrite() manages
410 * writes to WR0 and WR8 differently, because these can be accessed
411 * directly with less overhead. Another special case are WR7 and WR7'.
412 * _SCCwrite automatically checks what of this registers is selected
413 * and changes b0 of WR15 if needed.
414 *
415 * _SCCread() for standard read registers is straightforward, except
416 * for RR2 (split into two "virtual" registers: one for the value
417 * written to WR2 (from the shadow) and one for the vector including
418 * status from RR2, Ch. B) and RR3. The latter must be read from
419 * Channel A, because it reads as all zeros on Ch. B. RR0 and RR8 can
420 * be accessed directly as before.
421 *
422 * The two inline function contain complicated switch statements. But
423 * I rely on regno and final_delay being constants, so gcc can reduce
424 * the whole stuff to just some assembler statements.
425 *
426 * _SCCwrite and _SCCread aren't intended to be used directly under
427 * normal circumstances. The macros SCCread[_ND] and SCCwrite[_ND] are
428 * for that purpose. They assume that a local variable 'port' is
429 * declared and pointing to the port's scc_struct entry. The
430 * variants with "_NB" appended should be used if no other SCC
431 * accesses follow immediately (within 0.5 usecs). They just skip the
432 * final delay nops.
433 *
434 * Please note that accesses to SCC registers should only take place
435 * when interrupts are turned off (at least if SCC interrupts are
436 * enabled). Otherwise, an interrupt could interfere with the
437 * two-stage accessing process.
438 *
439 */
440
441
_SCCwrite(struct scc_port * port,unsigned char * shadow,volatile unsigned char * _scc_del,int regno,unsigned char val,int final_delay)442 static __inline__ void _SCCwrite(
443 struct scc_port *port,
444 unsigned char *shadow,
445 volatile unsigned char *_scc_del,
446 int regno,
447 unsigned char val, int final_delay )
448 {
449 switch( regno ) {
450
451 case COMMAND_REG:
452 /* WR0 can be written directly without pointing */
453 *port->ctrlp = val;
454 break;
455
456 case SYNC_CHAR_REG:
457 /* For WR7, first set b0 of WR15 to 0, if needed */
458 if (shadow[INT_CTRL_REG] & ICR_OPTIONREG_SELECT) {
459 *port->ctrlp = 15;
460 shadow[INT_CTRL_REG] &= ~ICR_OPTIONREG_SELECT;
461 scc_reg_delay();
462 *port->ctrlp = shadow[INT_CTRL_REG];
463 scc_reg_delay();
464 }
465 goto normal_case;
466
467 case SDLC_OPTION_REG:
468 /* For WR7', first set b0 of WR15 to 1, if needed */
469 if (!(shadow[INT_CTRL_REG] & ICR_OPTIONREG_SELECT)) {
470 *port->ctrlp = 15;
471 shadow[INT_CTRL_REG] |= ICR_OPTIONREG_SELECT;
472 scc_reg_delay();
473 *port->ctrlp = shadow[INT_CTRL_REG];
474 scc_reg_delay();
475 }
476 *port->ctrlp = 7;
477 shadow[8] = val; /* WR7' shadowed at WR8 */
478 scc_reg_delay();
479 *port->ctrlp = val;
480 break;
481
482 case TX_DATA_REG: /* WR8 */
483 /* TX_DATA_REG can be accessed directly on some h/w */
484 if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147)
485 {
486 *port->ctrlp = regno;
487 scc_reg_delay();
488 *port->ctrlp = val;
489 }
490 else
491 *port->datap = val;
492 break;
493
494 case MASTER_INT_CTRL:
495 *port->ctrlp = regno;
496 val &= 0x3f; /* bits 6..7 are the reset commands */
497 scc_shadow[0][regno] = val;
498 scc_reg_delay();
499 *port->ctrlp = val;
500 break;
501
502 case DPLL_CTRL_REG:
503 *port->ctrlp = regno;
504 val &= 0x1f; /* bits 5..7 are the DPLL commands */
505 shadow[regno] = val;
506 scc_reg_delay();
507 *port->ctrlp = val;
508 break;
509
510 case 1 ... 6:
511 case 10 ... 13:
512 case 15:
513 normal_case:
514 *port->ctrlp = regno;
515 shadow[regno] = val;
516 scc_reg_delay();
517 *port->ctrlp = val;
518 break;
519
520 default:
521 printk( "Bad SCC write access to WR%d\n", regno );
522 break;
523
524 }
525
526 if (final_delay)
527 scc_reg_delay();
528 }
529
530
_SCCread(struct scc_port * port,unsigned char * shadow,volatile unsigned char * _scc_del,int regno,int final_delay)531 static __inline__ unsigned char _SCCread(
532 struct scc_port *port,
533 unsigned char *shadow,
534 volatile unsigned char *_scc_del,
535 int regno, int final_delay )
536 {
537 unsigned char rv;
538
539 switch( regno ) {
540
541 /* --- real read registers --- */
542 case STATUS_REG:
543 rv = *port->ctrlp;
544 break;
545
546 case INT_PENDING_REG:
547 /* RR3: read only from Channel A! */
548 port = port->port_a;
549 goto normal_case;
550
551 case RX_DATA_REG:
552 /* RR8 can be accessed directly on some h/w */
553 if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147)
554 {
555 *port->ctrlp = 8;
556 scc_reg_delay();
557 rv = *port->ctrlp;
558 }
559 else
560 rv = *port->datap;
561 break;
562
563 case CURR_VECTOR_REG:
564 /* RR2 (vector including status) from Ch. B */
565 port = port->port_b;
566 goto normal_case;
567
568 /* --- reading write registers: access the shadow --- */
569 case 1 ... 7:
570 case 10 ... 15:
571 return shadow[regno]; /* no final delay! */
572
573 /* WR7' is special, because it is shadowed at the place of WR8 */
574 case SDLC_OPTION_REG:
575 return shadow[8]; /* no final delay! */
576
577 /* WR9 is special too, because it is common for both channels */
578 case MASTER_INT_CTRL:
579 return scc_shadow[0][9]; /* no final delay! */
580
581 default:
582 printk( "Bad SCC read access to %cR%d\n", (regno & 16) ? 'R' : 'W',
583 regno & ~16 );
584 break;
585
586 case SPCOND_STATUS_REG:
587 case FS_FIFO_LOW_REG:
588 case FS_FIFO_HIGH_REG:
589 case DPLL_STATUS_REG:
590 normal_case:
591 *port->ctrlp = regno & 0x0f;
592 scc_reg_delay();
593 rv = *port->ctrlp;
594 break;
595
596 }
597
598 if (final_delay)
599 scc_reg_delay();
600 return rv;
601 }
602
603 #define SCC_ACCESS_INIT(port) \
604 unsigned char *_scc_shadow = &scc_shadow[port->channel][0]
605
606 #define SCCwrite(reg,val) _SCCwrite(port,_scc_shadow,scc_del,(reg),(val),1)
607 #define SCCwrite_NB(reg,val) _SCCwrite(port,_scc_shadow,scc_del,(reg),(val),0)
608 #define SCCread(reg) _SCCread(port,_scc_shadow,scc_del,(reg),1)
609 #define SCCread_NB(reg) _SCCread(port,_scc_shadow,scc_del,(reg),0)
610
611 #define SCCmod(reg,and,or) SCCwrite((reg),(SCCread(reg)&(and))|(or))
612
613 #endif /* _SCC_H */
614