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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
47struct 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
75struct 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().
Geert Uytterhoeven3d92e8f2009-02-22 09:38:47 +0100390 * 10/16/95: A tstb st_mfp.par_dt_reg takes 600ns (sure?) and thus should be
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 * 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
Al Virodf87ac92006-01-12 01:06:16 -0800402static unsigned char scc_shadow[2][16];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
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
442static __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
531static __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 */