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Linux 3.11-rc3
[cris-mirror.git] / drivers / tty / serial / zs.c
blob6a169877109b264ff8d060ba8b5929adfc0c78a0
1 /*
2 * zs.c: Serial port driver for IOASIC DECstations.
3 *
4 * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
5 * Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
6 *
7 * DECstation changes
8 * Copyright (C) 1998-2000 Harald Koerfgen
9 * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
10 *
11 * For the rest of the code the original Copyright applies:
12 * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
13 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
14 *
15 *
16 * Note: for IOASIC systems the wiring is as follows:
17 *
18 * mouse/keyboard:
19 * DIN-7 MJ-4 signal SCC
20 * 2 1 TxD <- A.TxD
21 * 3 4 RxD -> A.RxD
22 *
23 * EIA-232/EIA-423:
24 * DB-25 MMJ-6 signal SCC
25 * 2 2 TxD <- B.TxD
26 * 3 5 RxD -> B.RxD
27 * 4 RTS <- ~A.RTS
28 * 5 CTS -> ~B.CTS
29 * 6 6 DSR -> ~A.SYNC
30 * 8 CD -> ~B.DCD
31 * 12 DSRS(DCE) -> ~A.CTS (*)
32 * 15 TxC -> B.TxC
33 * 17 RxC -> B.RxC
34 * 20 1 DTR <- ~A.DTR
35 * 22 RI -> ~A.DCD
36 * 23 DSRS(DTE) <- ~B.RTS
37 *
38 * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
39 * is shared with DSRS(DTE) at pin 23.
40 *
41 * As you can immediately notice the wiring of the RTS, DTR and DSR signals
42 * is a bit odd. This makes the handling of port B unnecessarily
43 * complicated and prevents the use of some automatic modes of operation.
44 */
45
46 #if defined(CONFIG_SERIAL_ZS_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
47 #define SUPPORT_SYSRQ
48 #endif
49
50 #include <linux/bug.h>
51 #include <linux/console.h>
52 #include <linux/delay.h>
53 #include <linux/errno.h>
54 #include <linux/init.h>
55 #include <linux/interrupt.h>
56 #include <linux/io.h>
57 #include <linux/ioport.h>
58 #include <linux/irqflags.h>
59 #include <linux/kernel.h>
60 #include <linux/module.h>
61 #include <linux/major.h>
62 #include <linux/serial.h>
63 #include <linux/serial_core.h>
64 #include <linux/spinlock.h>
65 #include <linux/sysrq.h>
66 #include <linux/tty.h>
67 #include <linux/tty_flip.h>
68 #include <linux/types.h>
69
70 #include <linux/atomic.h>
71
72 #include <asm/dec/interrupts.h>
73 #include <asm/dec/ioasic_addrs.h>
74 #include <asm/dec/system.h>
75
76 #include "zs.h"
77
78
79 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
80 MODULE_DESCRIPTION("DECstation Z85C30 serial driver");
81 MODULE_LICENSE("GPL");
82
83
84 static char zs_name[] __initdata = "DECstation Z85C30 serial driver version ";
85 static char zs_version[] __initdata = "0.10";
86
87 /*
88 * It would be nice to dynamically allocate everything that
89 * depends on ZS_NUM_SCCS, so we could support any number of
90 * Z85C30s, but for now...
91 */
92 #define ZS_NUM_SCCS 2 /* Max # of ZS chips supported. */
93 #define ZS_NUM_CHAN 2 /* 2 channels per chip. */
94 #define ZS_CHAN_A 0 /* Index of the channel A. */
95 #define ZS_CHAN_B 1 /* Index of the channel B. */
96 #define ZS_CHAN_IO_SIZE 8 /* IOMEM space size. */
97 #define ZS_CHAN_IO_STRIDE 4 /* Register alignment. */
98 #define ZS_CHAN_IO_OFFSET 1 /* The SCC resides on the high byte
99 of the 16-bit IOBUS. */
100 #define ZS_CLOCK 7372800 /* Z85C30 PCLK input clock rate. */
101
102 #define to_zport(uport) container_of(uport, struct zs_port, port)
103
104 struct zs_parms {
105 resource_size_t scc[ZS_NUM_SCCS];
106 int irq[ZS_NUM_SCCS];
107 };
108
109 static struct zs_scc zs_sccs[ZS_NUM_SCCS];
110
111 static u8 zs_init_regs[ZS_NUM_REGS] __initdata = {
112 0, /* write 0 */
113 PAR_SPEC, /* write 1 */
114 0, /* write 2 */
115 0, /* write 3 */
116 X16CLK | SB1, /* write 4 */
117 0, /* write 5 */
118 0, 0, 0, /* write 6, 7, 8 */
119 MIE | DLC | NV, /* write 9 */
120 NRZ, /* write 10 */
121 TCBR | RCBR, /* write 11 */
122 0, 0, /* BRG time constant, write 12 + 13 */
123 BRSRC | BRENABL, /* write 14 */
124 0, /* write 15 */
125 };
126
127 /*
128 * Debugging.
129 */
130 #undef ZS_DEBUG_REGS
131
132
133 /*
134 * Reading and writing Z85C30 registers.
135 */
136 static void recovery_delay(void)
137 {
138 udelay(2);
139 }
140
141 static u8 read_zsreg(struct zs_port *zport, int reg)
142 {
143 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
144 u8 retval;
145
146 if (reg != 0) {
147 writeb(reg & 0xf, control);
148 fast_iob();
149 recovery_delay();
150 }
151 retval = readb(control);
152 recovery_delay();
153 return retval;
154 }
155
156 static void write_zsreg(struct zs_port *zport, int reg, u8 value)
157 {
158 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
159
160 if (reg != 0) {
161 writeb(reg & 0xf, control);
162 fast_iob(); recovery_delay();
163 }
164 writeb(value, control);
165 fast_iob();
166 recovery_delay();
167 return;
168 }
169
170 static u8 read_zsdata(struct zs_port *zport)
171 {
172 void __iomem *data = zport->port.membase +
173 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
174 u8 retval;
175
176 retval = readb(data);
177 recovery_delay();
178 return retval;
179 }
180
181 static void write_zsdata(struct zs_port *zport, u8 value)
182 {
183 void __iomem *data = zport->port.membase +
184 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
185
186 writeb(value, data);
187 fast_iob();
188 recovery_delay();
189 return;
190 }
191
192 #ifdef ZS_DEBUG_REGS
193 void zs_dump(void)
194 {
195 struct zs_port *zport;
196 int i, j;
197
198 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
199 zport = &zs_sccs[i / ZS_NUM_CHAN].zport[i % ZS_NUM_CHAN];
200
201 if (!zport->scc)
202 continue;
203
204 for (j = 0; j < 16; j++)
205 printk("W%-2d = 0x%02x\t", j, zport->regs[j]);
206 printk("\n");
207 for (j = 0; j < 16; j++)
208 printk("R%-2d = 0x%02x\t", j, read_zsreg(zport, j));
209 printk("\n\n");
210 }
211 }
212 #endif
213
214
215 static void zs_spin_lock_cond_irq(spinlock_t *lock, int irq)
216 {
217 if (irq)
218 spin_lock_irq(lock);
219 else
220 spin_lock(lock);
221 }
222
223 static void zs_spin_unlock_cond_irq(spinlock_t *lock, int irq)
224 {
225 if (irq)
226 spin_unlock_irq(lock);
227 else
228 spin_unlock(lock);
229 }
230
231 static int zs_receive_drain(struct zs_port *zport)
232 {
233 int loops = 10000;
234
235 while ((read_zsreg(zport, R0) & Rx_CH_AV) && --loops)
236 read_zsdata(zport);
237 return loops;
238 }
239
240 static int zs_transmit_drain(struct zs_port *zport, int irq)
241 {
242 struct zs_scc *scc = zport->scc;
243 int loops = 10000;
244
245 while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && --loops) {
246 zs_spin_unlock_cond_irq(&scc->zlock, irq);
247 udelay(2);
248 zs_spin_lock_cond_irq(&scc->zlock, irq);
249 }
250 return loops;
251 }
252
253 static int zs_line_drain(struct zs_port *zport, int irq)
254 {
255 struct zs_scc *scc = zport->scc;
256 int loops = 10000;
257
258 while (!(read_zsreg(zport, R1) & ALL_SNT) && --loops) {
259 zs_spin_unlock_cond_irq(&scc->zlock, irq);
260 udelay(2);
261 zs_spin_lock_cond_irq(&scc->zlock, irq);
262 }
263 return loops;
264 }
265
266
267 static void load_zsregs(struct zs_port *zport, u8 *regs, int irq)
268 {
269 /* Let the current transmission finish. */
270 zs_line_drain(zport, irq);
271 /* Load 'em up. */
272 write_zsreg(zport, R3, regs[3] & ~RxENABLE);
273 write_zsreg(zport, R5, regs[5] & ~TxENAB);
274 write_zsreg(zport, R4, regs[4]);
275 write_zsreg(zport, R9, regs[9]);
276 write_zsreg(zport, R1, regs[1]);
277 write_zsreg(zport, R2, regs[2]);
278 write_zsreg(zport, R10, regs[10]);
279 write_zsreg(zport, R14, regs[14] & ~BRENABL);
280 write_zsreg(zport, R11, regs[11]);
281 write_zsreg(zport, R12, regs[12]);
282 write_zsreg(zport, R13, regs[13]);
283 write_zsreg(zport, R14, regs[14]);
284 write_zsreg(zport, R15, regs[15]);
285 if (regs[3] & RxENABLE)
286 write_zsreg(zport, R3, regs[3]);
287 if (regs[5] & TxENAB)
288 write_zsreg(zport, R5, regs[5]);
289 return;
290 }
291
292
293 /*
294 * Status handling routines.
295 */
296
297 /*
298 * zs_tx_empty() -- get the transmitter empty status
299 *
300 * Purpose: Let user call ioctl() to get info when the UART physically
301 * is emptied. On bus types like RS485, the transmitter must
302 * release the bus after transmitting. This must be done when
303 * the transmit shift register is empty, not be done when the
304 * transmit holding register is empty. This functionality
305 * allows an RS485 driver to be written in user space.
306 */
307 static unsigned int zs_tx_empty(struct uart_port *uport)
308 {
309 struct zs_port *zport = to_zport(uport);
310 struct zs_scc *scc = zport->scc;
311 unsigned long flags;
312 u8 status;
313
314 spin_lock_irqsave(&scc->zlock, flags);
315 status = read_zsreg(zport, R1);
316 spin_unlock_irqrestore(&scc->zlock, flags);
317
318 return status & ALL_SNT ? TIOCSER_TEMT : 0;
319 }
320
321 static unsigned int zs_raw_get_ab_mctrl(struct zs_port *zport_a,
322 struct zs_port *zport_b)
323 {
324 u8 status_a, status_b;
325 unsigned int mctrl;
326
327 status_a = read_zsreg(zport_a, R0);
328 status_b = read_zsreg(zport_b, R0);
329
330 mctrl = ((status_b & CTS) ? TIOCM_CTS : 0) |
331 ((status_b & DCD) ? TIOCM_CAR : 0) |
332 ((status_a & DCD) ? TIOCM_RNG : 0) |
333 ((status_a & SYNC_HUNT) ? TIOCM_DSR : 0);
334
335 return mctrl;
336 }
337
338 static unsigned int zs_raw_get_mctrl(struct zs_port *zport)
339 {
340 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
341
342 return zport != zport_a ? zs_raw_get_ab_mctrl(zport_a, zport) : 0;
343 }
344
345 static unsigned int zs_raw_xor_mctrl(struct zs_port *zport)
346 {
347 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
348 unsigned int mmask, mctrl, delta;
349 u8 mask_a, mask_b;
350
351 if (zport == zport_a)
352 return 0;
353
354 mask_a = zport_a->regs[15];
355 mask_b = zport->regs[15];
356
357 mmask = ((mask_b & CTSIE) ? TIOCM_CTS : 0) |
358 ((mask_b & DCDIE) ? TIOCM_CAR : 0) |
359 ((mask_a & DCDIE) ? TIOCM_RNG : 0) |
360 ((mask_a & SYNCIE) ? TIOCM_DSR : 0);
361
362 mctrl = zport->mctrl;
363 if (mmask) {
364 mctrl &= ~mmask;
365 mctrl |= zs_raw_get_ab_mctrl(zport_a, zport) & mmask;
366 }
367
368 delta = mctrl ^ zport->mctrl;
369 if (delta)
370 zport->mctrl = mctrl;
371
372 return delta;
373 }
374
375 static unsigned int zs_get_mctrl(struct uart_port *uport)
376 {
377 struct zs_port *zport = to_zport(uport);
378 struct zs_scc *scc = zport->scc;
379 unsigned int mctrl;
380
381 spin_lock(&scc->zlock);
382 mctrl = zs_raw_get_mctrl(zport);
383 spin_unlock(&scc->zlock);
384
385 return mctrl;
386 }
387
388 static void zs_set_mctrl(struct uart_port *uport, unsigned int mctrl)
389 {
390 struct zs_port *zport = to_zport(uport);
391 struct zs_scc *scc = zport->scc;
392 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
393 u8 oldloop, newloop;
394
395 spin_lock(&scc->zlock);
396 if (zport != zport_a) {
397 if (mctrl & TIOCM_DTR)
398 zport_a->regs[5] |= DTR;
399 else
400 zport_a->regs[5] &= ~DTR;
401 if (mctrl & TIOCM_RTS)
402 zport_a->regs[5] |= RTS;
403 else
404 zport_a->regs[5] &= ~RTS;
405 write_zsreg(zport_a, R5, zport_a->regs[5]);
406 }
407
408 /* Rarely modified, so don't poke at hardware unless necessary. */
409 oldloop = zport->regs[14];
410 newloop = oldloop;
411 if (mctrl & TIOCM_LOOP)
412 newloop |= LOOPBAK;
413 else
414 newloop &= ~LOOPBAK;
415 if (newloop != oldloop) {
416 zport->regs[14] = newloop;
417 write_zsreg(zport, R14, zport->regs[14]);
418 }
419 spin_unlock(&scc->zlock);
420 }
421
422 static void zs_raw_stop_tx(struct zs_port *zport)
423 {
424 write_zsreg(zport, R0, RES_Tx_P);
425 zport->tx_stopped = 1;
426 }
427
428 static void zs_stop_tx(struct uart_port *uport)
429 {
430 struct zs_port *zport = to_zport(uport);
431 struct zs_scc *scc = zport->scc;
432
433 spin_lock(&scc->zlock);
434 zs_raw_stop_tx(zport);
435 spin_unlock(&scc->zlock);
436 }
437
438 static void zs_raw_transmit_chars(struct zs_port *);
439
440 static void zs_start_tx(struct uart_port *uport)
441 {
442 struct zs_port *zport = to_zport(uport);
443 struct zs_scc *scc = zport->scc;
444
445 spin_lock(&scc->zlock);
446 if (zport->tx_stopped) {
447 zs_transmit_drain(zport, 0);
448 zport->tx_stopped = 0;
449 zs_raw_transmit_chars(zport);
450 }
451 spin_unlock(&scc->zlock);
452 }
453
454 static void zs_stop_rx(struct uart_port *uport)
455 {
456 struct zs_port *zport = to_zport(uport);
457 struct zs_scc *scc = zport->scc;
458 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
459
460 spin_lock(&scc->zlock);
461 zport->regs[15] &= ~BRKIE;
462 zport->regs[1] &= ~(RxINT_MASK | TxINT_ENAB);
463 zport->regs[1] |= RxINT_DISAB;
464
465 if (zport != zport_a) {
466 /* A-side DCD tracks RI and SYNC tracks DSR. */
467 zport_a->regs[15] &= ~(DCDIE | SYNCIE);
468 write_zsreg(zport_a, R15, zport_a->regs[15]);
469 if (!(zport_a->regs[15] & BRKIE)) {
470 zport_a->regs[1] &= ~EXT_INT_ENAB;
471 write_zsreg(zport_a, R1, zport_a->regs[1]);
472 }
473
474 /* This-side DCD tracks DCD and CTS tracks CTS. */
475 zport->regs[15] &= ~(DCDIE | CTSIE);
476 zport->regs[1] &= ~EXT_INT_ENAB;
477 } else {
478 /* DCD tracks RI and SYNC tracks DSR for the B side. */
479 if (!(zport->regs[15] & (DCDIE | SYNCIE)))
480 zport->regs[1] &= ~EXT_INT_ENAB;
481 }
482
483 write_zsreg(zport, R15, zport->regs[15]);
484 write_zsreg(zport, R1, zport->regs[1]);
485 spin_unlock(&scc->zlock);
486 }
487
488 static void zs_enable_ms(struct uart_port *uport)
489 {
490 struct zs_port *zport = to_zport(uport);
491 struct zs_scc *scc = zport->scc;
492 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
493
494 if (zport == zport_a)
495 return;
496
497 spin_lock(&scc->zlock);
498
499 /* Clear Ext interrupts if not being handled already. */
500 if (!(zport_a->regs[1] & EXT_INT_ENAB))
501 write_zsreg(zport_a, R0, RES_EXT_INT);
502
503 /* A-side DCD tracks RI and SYNC tracks DSR. */
504 zport_a->regs[1] |= EXT_INT_ENAB;
505 zport_a->regs[15] |= DCDIE | SYNCIE;
506
507 /* This-side DCD tracks DCD and CTS tracks CTS. */
508 zport->regs[15] |= DCDIE | CTSIE;
509
510 zs_raw_xor_mctrl(zport);
511
512 write_zsreg(zport_a, R1, zport_a->regs[1]);
513 write_zsreg(zport_a, R15, zport_a->regs[15]);
514 write_zsreg(zport, R15, zport->regs[15]);
515 spin_unlock(&scc->zlock);
516 }
517
518 static void zs_break_ctl(struct uart_port *uport, int break_state)
519 {
520 struct zs_port *zport = to_zport(uport);
521 struct zs_scc *scc = zport->scc;
522 unsigned long flags;
523
524 spin_lock_irqsave(&scc->zlock, flags);
525 if (break_state == -1)
526 zport->regs[5] |= SND_BRK;
527 else
528 zport->regs[5] &= ~SND_BRK;
529 write_zsreg(zport, R5, zport->regs[5]);
530 spin_unlock_irqrestore(&scc->zlock, flags);
531 }
532
533
534 /*
535 * Interrupt handling routines.
536 */
537 #define Rx_BRK 0x0100 /* BREAK event software flag. */
538 #define Rx_SYS 0x0200 /* SysRq event software flag. */
539
540 static void zs_receive_chars(struct zs_port *zport)
541 {
542 struct uart_port *uport = &zport->port;
543 struct zs_scc *scc = zport->scc;
544 struct uart_icount *icount;
545 unsigned int avail, status, ch, flag;
546 int count;
547
548 for (count = 16; count; count--) {
549 spin_lock(&scc->zlock);
550 avail = read_zsreg(zport, R0) & Rx_CH_AV;
551 spin_unlock(&scc->zlock);
552 if (!avail)
553 break;
554
555 spin_lock(&scc->zlock);
556 status = read_zsreg(zport, R1) & (Rx_OVR | FRM_ERR | PAR_ERR);
557 ch = read_zsdata(zport);
558 spin_unlock(&scc->zlock);
559
560 flag = TTY_NORMAL;
561
562 icount = &uport->icount;
563 icount->rx++;
564
565 /* Handle the null char got when BREAK is removed. */
566 if (!ch)
567 status |= zport->tty_break;
568 if (unlikely(status &
569 (Rx_OVR | FRM_ERR | PAR_ERR | Rx_SYS | Rx_BRK))) {
570 zport->tty_break = 0;
571
572 /* Reset the error indication. */
573 if (status & (Rx_OVR | FRM_ERR | PAR_ERR)) {
574 spin_lock(&scc->zlock);
575 write_zsreg(zport, R0, ERR_RES);
576 spin_unlock(&scc->zlock);
577 }
578
579 if (status & (Rx_SYS | Rx_BRK)) {
580 icount->brk++;
581 /* SysRq discards the null char. */
582 if (status & Rx_SYS)
583 continue;
584 } else if (status & FRM_ERR)
585 icount->frame++;
586 else if (status & PAR_ERR)
587 icount->parity++;
588 if (status & Rx_OVR)
589 icount->overrun++;
590
591 status &= uport->read_status_mask;
592 if (status & Rx_BRK)
593 flag = TTY_BREAK;
594 else if (status & FRM_ERR)
595 flag = TTY_FRAME;
596 else if (status & PAR_ERR)
597 flag = TTY_PARITY;
598 }
599
600 if (uart_handle_sysrq_char(uport, ch))
601 continue;
602
603 uart_insert_char(uport, status, Rx_OVR, ch, flag);
604 }
605
606 tty_flip_buffer_push(&uport->state->port);
607 }
608
609 static void zs_raw_transmit_chars(struct zs_port *zport)
610 {
611 struct circ_buf *xmit = &zport->port.state->xmit;
612
613 /* XON/XOFF chars. */
614 if (zport->port.x_char) {
615 write_zsdata(zport, zport->port.x_char);
616 zport->port.icount.tx++;
617 zport->port.x_char = 0;
618 return;
619 }
620
621 /* If nothing to do or stopped or hardware stopped. */
622 if (uart_circ_empty(xmit) || uart_tx_stopped(&zport->port)) {
623 zs_raw_stop_tx(zport);
624 return;
625 }
626
627 /* Send char. */
628 write_zsdata(zport, xmit->buf[xmit->tail]);
629 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
630 zport->port.icount.tx++;
631
632 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
633 uart_write_wakeup(&zport->port);
634
635 /* Are we are done? */
636 if (uart_circ_empty(xmit))
637 zs_raw_stop_tx(zport);
638 }
639
640 static void zs_transmit_chars(struct zs_port *zport)
641 {
642 struct zs_scc *scc = zport->scc;
643
644 spin_lock(&scc->zlock);
645 zs_raw_transmit_chars(zport);
646 spin_unlock(&scc->zlock);
647 }
648
649 static void zs_status_handle(struct zs_port *zport, struct zs_port *zport_a)
650 {
651 struct uart_port *uport = &zport->port;
652 struct zs_scc *scc = zport->scc;
653 unsigned int delta;
654 u8 status, brk;
655
656 spin_lock(&scc->zlock);
657
658 /* Get status from Read Register 0. */
659 status = read_zsreg(zport, R0);
660
661 if (zport->regs[15] & BRKIE) {
662 brk = status & BRK_ABRT;
663 if (brk && !zport->brk) {
664 spin_unlock(&scc->zlock);
665 if (uart_handle_break(uport))
666 zport->tty_break = Rx_SYS;
667 else
668 zport->tty_break = Rx_BRK;
669 spin_lock(&scc->zlock);
670 }
671 zport->brk = brk;
672 }
673
674 if (zport != zport_a) {
675 delta = zs_raw_xor_mctrl(zport);
676 spin_unlock(&scc->zlock);
677
678 if (delta & TIOCM_CTS)
679 uart_handle_cts_change(uport,
680 zport->mctrl & TIOCM_CTS);
681 if (delta & TIOCM_CAR)
682 uart_handle_dcd_change(uport,
683 zport->mctrl & TIOCM_CAR);
684 if (delta & TIOCM_RNG)
685 uport->icount.dsr++;
686 if (delta & TIOCM_DSR)
687 uport->icount.rng++;
688
689 if (delta)
690 wake_up_interruptible(&uport->state->port.delta_msr_wait);
691
692 spin_lock(&scc->zlock);
693 }
694
695 /* Clear the status condition... */
696 write_zsreg(zport, R0, RES_EXT_INT);
697
698 spin_unlock(&scc->zlock);
699 }
700
701 /*
702 * This is the Z85C30 driver's generic interrupt routine.
703 */
704 static irqreturn_t zs_interrupt(int irq, void *dev_id)
705 {
706 struct zs_scc *scc = dev_id;
707 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
708 struct zs_port *zport_b = &scc->zport[ZS_CHAN_B];
709 irqreturn_t status = IRQ_NONE;
710 u8 zs_intreg;
711 int count;
712
713 /*
714 * NOTE: The read register 3, which holds the irq status,
715 * does so for both channels on each chip. Although
716 * the status value itself must be read from the A
717 * channel and is only valid when read from channel A.
718 * Yes... broken hardware...
719 */
720 for (count = 16; count; count--) {
721 spin_lock(&scc->zlock);
722 zs_intreg = read_zsreg(zport_a, R3);
723 spin_unlock(&scc->zlock);
724 if (!zs_intreg)
725 break;
726
727 /*
728 * We do not like losing characters, so we prioritise
729 * interrupt sources a little bit differently than
730 * the SCC would, was it allowed to.
731 */
732 if (zs_intreg & CHBRxIP)
733 zs_receive_chars(zport_b);
734 if (zs_intreg & CHARxIP)
735 zs_receive_chars(zport_a);
736 if (zs_intreg & CHBEXT)
737 zs_status_handle(zport_b, zport_a);
738 if (zs_intreg & CHAEXT)
739 zs_status_handle(zport_a, zport_a);
740 if (zs_intreg & CHBTxIP)
741 zs_transmit_chars(zport_b);
742 if (zs_intreg & CHATxIP)
743 zs_transmit_chars(zport_a);
744
745 status = IRQ_HANDLED;
746 }
747
748 return status;
749 }
750
751
752 /*
753 * Finally, routines used to initialize the serial port.
754 */
755 static int zs_startup(struct uart_port *uport)
756 {
757 struct zs_port *zport = to_zport(uport);
758 struct zs_scc *scc = zport->scc;
759 unsigned long flags;
760 int irq_guard;
761 int ret;
762
763 irq_guard = atomic_add_return(1, &scc->irq_guard);
764 if (irq_guard == 1) {
765 ret = request_irq(zport->port.irq, zs_interrupt,
766 IRQF_SHARED, "scc", scc);
767 if (ret) {
768 atomic_add(-1, &scc->irq_guard);
769 printk(KERN_ERR "zs: can't get irq %d\n",
770 zport->port.irq);
771 return ret;
772 }
773 }
774
775 spin_lock_irqsave(&scc->zlock, flags);
776
777 /* Clear the receive FIFO. */
778 zs_receive_drain(zport);
779
780 /* Clear the interrupt registers. */
781 write_zsreg(zport, R0, ERR_RES);
782 write_zsreg(zport, R0, RES_Tx_P);
783 /* But Ext only if not being handled already. */
784 if (!(zport->regs[1] & EXT_INT_ENAB))
785 write_zsreg(zport, R0, RES_EXT_INT);
786
787 /* Finally, enable sequencing and interrupts. */
788 zport->regs[1] &= ~RxINT_MASK;
789 zport->regs[1] |= RxINT_ALL | TxINT_ENAB | EXT_INT_ENAB;
790 zport->regs[3] |= RxENABLE;
791 zport->regs[15] |= BRKIE;
792 write_zsreg(zport, R1, zport->regs[1]);
793 write_zsreg(zport, R3, zport->regs[3]);
794 write_zsreg(zport, R5, zport->regs[5]);
795 write_zsreg(zport, R15, zport->regs[15]);
796
797 /* Record the current state of RR0. */
798 zport->mctrl = zs_raw_get_mctrl(zport);
799 zport->brk = read_zsreg(zport, R0) & BRK_ABRT;
800
801 zport->tx_stopped = 1;
802
803 spin_unlock_irqrestore(&scc->zlock, flags);
804
805 return 0;
806 }
807
808 static void zs_shutdown(struct uart_port *uport)
809 {
810 struct zs_port *zport = to_zport(uport);
811 struct zs_scc *scc = zport->scc;
812 unsigned long flags;
813 int irq_guard;
814
815 spin_lock_irqsave(&scc->zlock, flags);
816
817 zport->regs[3] &= ~RxENABLE;
818 write_zsreg(zport, R5, zport->regs[5]);
819 write_zsreg(zport, R3, zport->regs[3]);
820
821 spin_unlock_irqrestore(&scc->zlock, flags);
822
823 irq_guard = atomic_add_return(-1, &scc->irq_guard);
824 if (!irq_guard)
825 free_irq(zport->port.irq, scc);
826 }
827
828
829 static void zs_reset(struct zs_port *zport)
830 {
831 struct zs_scc *scc = zport->scc;
832 int irq;
833 unsigned long flags;
834
835 spin_lock_irqsave(&scc->zlock, flags);
836 irq = !irqs_disabled_flags(flags);
837 if (!scc->initialised) {
838 /* Reset the pointer first, just in case... */
839 read_zsreg(zport, R0);
840 /* And let the current transmission finish. */
841 zs_line_drain(zport, irq);
842 write_zsreg(zport, R9, FHWRES);
843 udelay(10);
844 write_zsreg(zport, R9, 0);
845 scc->initialised = 1;
846 }
847 load_zsregs(zport, zport->regs, irq);
848 spin_unlock_irqrestore(&scc->zlock, flags);
849 }
850
851 static void zs_set_termios(struct uart_port *uport, struct ktermios *termios,
852 struct ktermios *old_termios)
853 {
854 struct zs_port *zport = to_zport(uport);
855 struct zs_scc *scc = zport->scc;
856 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
857 int irq;
858 unsigned int baud, brg;
859 unsigned long flags;
860
861 spin_lock_irqsave(&scc->zlock, flags);
862 irq = !irqs_disabled_flags(flags);
863
864 /* Byte size. */
865 zport->regs[3] &= ~RxNBITS_MASK;
866 zport->regs[5] &= ~TxNBITS_MASK;
867 switch (termios->c_cflag & CSIZE) {
868 case CS5:
869 zport->regs[3] |= Rx5;
870 zport->regs[5] |= Tx5;
871 break;
872 case CS6:
873 zport->regs[3] |= Rx6;
874 zport->regs[5] |= Tx6;
875 break;
876 case CS7:
877 zport->regs[3] |= Rx7;
878 zport->regs[5] |= Tx7;
879 break;
880 case CS8:
881 default:
882 zport->regs[3] |= Rx8;
883 zport->regs[5] |= Tx8;
884 break;
885 }
886
887 /* Parity and stop bits. */
888 zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN);
889 if (termios->c_cflag & CSTOPB)
890 zport->regs[4] |= SB2;
891 else
892 zport->regs[4] |= SB1;
893 if (termios->c_cflag & PARENB)
894 zport->regs[4] |= PAR_ENA;
895 if (!(termios->c_cflag & PARODD))
896 zport->regs[4] |= PAR_EVEN;
897 switch (zport->clk_mode) {
898 case 64:
899 zport->regs[4] |= X64CLK;
900 break;
901 case 32:
902 zport->regs[4] |= X32CLK;
903 break;
904 case 16:
905 zport->regs[4] |= X16CLK;
906 break;
907 case 1:
908 zport->regs[4] |= X1CLK;
909 break;
910 default:
911 BUG();
912 }
913
914 baud = uart_get_baud_rate(uport, termios, old_termios, 0,
915 uport->uartclk / zport->clk_mode / 4);
916
917 brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode);
918 zport->regs[12] = brg & 0xff;
919 zport->regs[13] = (brg >> 8) & 0xff;
920
921 uart_update_timeout(uport, termios->c_cflag, baud);
922
923 uport->read_status_mask = Rx_OVR;
924 if (termios->c_iflag & INPCK)
925 uport->read_status_mask |= FRM_ERR | PAR_ERR;
926 if (termios->c_iflag & (BRKINT | PARMRK))
927 uport->read_status_mask |= Rx_BRK;
928
929 uport->ignore_status_mask = 0;
930 if (termios->c_iflag & IGNPAR)
931 uport->ignore_status_mask |= FRM_ERR | PAR_ERR;
932 if (termios->c_iflag & IGNBRK) {
933 uport->ignore_status_mask |= Rx_BRK;
934 if (termios->c_iflag & IGNPAR)
935 uport->ignore_status_mask |= Rx_OVR;
936 }
937
938 if (termios->c_cflag & CREAD)
939 zport->regs[3] |= RxENABLE;
940 else
941 zport->regs[3] &= ~RxENABLE;
942
943 if (zport != zport_a) {
944 if (!(termios->c_cflag & CLOCAL)) {
945 zport->regs[15] |= DCDIE;
946 } else
947 zport->regs[15] &= ~DCDIE;
948 if (termios->c_cflag & CRTSCTS) {
949 zport->regs[15] |= CTSIE;
950 } else
951 zport->regs[15] &= ~CTSIE;
952 zs_raw_xor_mctrl(zport);
953 }
954
955 /* Load up the new values. */
956 load_zsregs(zport, zport->regs, irq);
957
958 spin_unlock_irqrestore(&scc->zlock, flags);
959 }
960
961 /*
962 * Hack alert!
963 * Required solely so that the initial PROM-based console
964 * works undisturbed in parallel with this one.
965 */
966 static void zs_pm(struct uart_port *uport, unsigned int state,
967 unsigned int oldstate)
968 {
969 struct zs_port *zport = to_zport(uport);
970
971 if (state < 3)
972 zport->regs[5] |= TxENAB;
973 else
974 zport->regs[5] &= ~TxENAB;
975 write_zsreg(zport, R5, zport->regs[5]);
976 }
977
978
979 static const char *zs_type(struct uart_port *uport)
980 {
981 return "Z85C30 SCC";
982 }
983
984 static void zs_release_port(struct uart_port *uport)
985 {
986 iounmap(uport->membase);
987 uport->membase = 0;
988 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
989 }
990
991 static int zs_map_port(struct uart_port *uport)
992 {
993 if (!uport->membase)
994 uport->membase = ioremap_nocache(uport->mapbase,
995 ZS_CHAN_IO_SIZE);
996 if (!uport->membase) {
997 printk(KERN_ERR "zs: Cannot map MMIO\n");
998 return -ENOMEM;
999 }
1000 return 0;
1001 }
1002
1003 static int zs_request_port(struct uart_port *uport)
1004 {
1005 int ret;
1006
1007 if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) {
1008 printk(KERN_ERR "zs: Unable to reserve MMIO resource\n");
1009 return -EBUSY;
1010 }
1011 ret = zs_map_port(uport);
1012 if (ret) {
1013 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
1014 return ret;
1015 }
1016 return 0;
1017 }
1018
1019 static void zs_config_port(struct uart_port *uport, int flags)
1020 {
1021 struct zs_port *zport = to_zport(uport);
1022
1023 if (flags & UART_CONFIG_TYPE) {
1024 if (zs_request_port(uport))
1025 return;
1026
1027 uport->type = PORT_ZS;
1028
1029 zs_reset(zport);
1030 }
1031 }
1032
1033 static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser)
1034 {
1035 struct zs_port *zport = to_zport(uport);
1036 int ret = 0;
1037
1038 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS)
1039 ret = -EINVAL;
1040 if (ser->irq != uport->irq)
1041 ret = -EINVAL;
1042 if (ser->baud_base != uport->uartclk / zport->clk_mode / 4)
1043 ret = -EINVAL;
1044 return ret;
1045 }
1046
1047
1048 static struct uart_ops zs_ops = {
1049 .tx_empty = zs_tx_empty,
1050 .set_mctrl = zs_set_mctrl,
1051 .get_mctrl = zs_get_mctrl,
1052 .stop_tx = zs_stop_tx,
1053 .start_tx = zs_start_tx,
1054 .stop_rx = zs_stop_rx,
1055 .enable_ms = zs_enable_ms,
1056 .break_ctl = zs_break_ctl,
1057 .startup = zs_startup,
1058 .shutdown = zs_shutdown,
1059 .set_termios = zs_set_termios,
1060 .pm = zs_pm,
1061 .type = zs_type,
1062 .release_port = zs_release_port,
1063 .request_port = zs_request_port,
1064 .config_port = zs_config_port,
1065 .verify_port = zs_verify_port,
1066 };
1067
1068 /*
1069 * Initialize Z85C30 port structures.
1070 */
1071 static int __init zs_probe_sccs(void)
1072 {
1073 static int probed;
1074 struct zs_parms zs_parms;
1075 int chip, side, irq;
1076 int n_chips = 0;
1077 int i;
1078
1079 if (probed)
1080 return 0;
1081
1082 irq = dec_interrupt[DEC_IRQ_SCC0];
1083 if (irq >= 0) {
1084 zs_parms.scc[n_chips] = IOASIC_SCC0;
1085 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0];
1086 n_chips++;
1087 }
1088 irq = dec_interrupt[DEC_IRQ_SCC1];
1089 if (irq >= 0) {
1090 zs_parms.scc[n_chips] = IOASIC_SCC1;
1091 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1];
1092 n_chips++;
1093 }
1094 if (!n_chips)
1095 return -ENXIO;
1096
1097 probed = 1;
1098
1099 for (chip = 0; chip < n_chips; chip++) {
1100 spin_lock_init(&zs_sccs[chip].zlock);
1101 for (side = 0; side < ZS_NUM_CHAN; side++) {
1102 struct zs_port *zport = &zs_sccs[chip].zport[side];
1103 struct uart_port *uport = &zport->port;
1104
1105 zport->scc = &zs_sccs[chip];
1106 zport->clk_mode = 16;
1107
1108 uport->irq = zs_parms.irq[chip];
1109 uport->uartclk = ZS_CLOCK;
1110 uport->fifosize = 1;
1111 uport->iotype = UPIO_MEM;
1112 uport->flags = UPF_BOOT_AUTOCONF;
1113 uport->ops = &zs_ops;
1114 uport->line = chip * ZS_NUM_CHAN + side;
1115 uport->mapbase = dec_kn_slot_base +
1116 zs_parms.scc[chip] +
1117 (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE;
1118
1119 for (i = 0; i < ZS_NUM_REGS; i++)
1120 zport->regs[i] = zs_init_regs[i];
1121 }
1122 }
1123
1124 return 0;
1125 }
1126
1127
1128 #ifdef CONFIG_SERIAL_ZS_CONSOLE
1129 static void zs_console_putchar(struct uart_port *uport, int ch)
1130 {
1131 struct zs_port *zport = to_zport(uport);
1132 struct zs_scc *scc = zport->scc;
1133 int irq;
1134 unsigned long flags;
1135
1136 spin_lock_irqsave(&scc->zlock, flags);
1137 irq = !irqs_disabled_flags(flags);
1138 if (zs_transmit_drain(zport, irq))
1139 write_zsdata(zport, ch);
1140 spin_unlock_irqrestore(&scc->zlock, flags);
1141 }
1142
1143 /*
1144 * Print a string to the serial port trying not to disturb
1145 * any possible real use of the port...
1146 */
1147 static void zs_console_write(struct console *co, const char *s,
1148 unsigned int count)
1149 {
1150 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1151 struct zs_port *zport = &zs_sccs[chip].zport[side];
1152 struct zs_scc *scc = zport->scc;
1153 unsigned long flags;
1154 u8 txint, txenb;
1155 int irq;
1156
1157 /* Disable transmit interrupts and enable the transmitter. */
1158 spin_lock_irqsave(&scc->zlock, flags);
1159 txint = zport->regs[1];
1160 txenb = zport->regs[5];
1161 if (txint & TxINT_ENAB) {
1162 zport->regs[1] = txint & ~TxINT_ENAB;
1163 write_zsreg(zport, R1, zport->regs[1]);
1164 }
1165 if (!(txenb & TxENAB)) {
1166 zport->regs[5] = txenb | TxENAB;
1167 write_zsreg(zport, R5, zport->regs[5]);
1168 }
1169 spin_unlock_irqrestore(&scc->zlock, flags);
1170
1171 uart_console_write(&zport->port, s, count, zs_console_putchar);
1172
1173 /* Restore transmit interrupts and the transmitter enable. */
1174 spin_lock_irqsave(&scc->zlock, flags);
1175 irq = !irqs_disabled_flags(flags);
1176 zs_line_drain(zport, irq);
1177 if (!(txenb & TxENAB)) {
1178 zport->regs[5] &= ~TxENAB;
1179 write_zsreg(zport, R5, zport->regs[5]);
1180 }
1181 if (txint & TxINT_ENAB) {
1182 zport->regs[1] |= TxINT_ENAB;
1183 write_zsreg(zport, R1, zport->regs[1]);
1184 }
1185 spin_unlock_irqrestore(&scc->zlock, flags);
1186 }
1187
1188 /*
1189 * Setup serial console baud/bits/parity. We do two things here:
1190 * - construct a cflag setting for the first uart_open()
1191 * - initialise the serial port
1192 * Return non-zero if we didn't find a serial port.
1193 */
1194 static int __init zs_console_setup(struct console *co, char *options)
1195 {
1196 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1197 struct zs_port *zport = &zs_sccs[chip].zport[side];
1198 struct uart_port *uport = &zport->port;
1199 int baud = 9600;
1200 int bits = 8;
1201 int parity = 'n';
1202 int flow = 'n';
1203 int ret;
1204
1205 ret = zs_map_port(uport);
1206 if (ret)
1207 return ret;
1208
1209 zs_reset(zport);
1210 zs_pm(uport, 0, -1);
1211
1212 if (options)
1213 uart_parse_options(options, &baud, &parity, &bits, &flow);
1214 return uart_set_options(uport, co, baud, parity, bits, flow);
1215 }
1216
1217 static struct uart_driver zs_reg;
1218 static struct console zs_console = {
1219 .name = "ttyS",
1220 .write = zs_console_write,
1221 .device = uart_console_device,
1222 .setup = zs_console_setup,
1223 .flags = CON_PRINTBUFFER,
1224 .index = -1,
1225 .data = &zs_reg,
1226 };
1227
1228 /*
1229 * Register console.
1230 */
1231 static int __init zs_serial_console_init(void)
1232 {
1233 int ret;
1234
1235 ret = zs_probe_sccs();
1236 if (ret)
1237 return ret;
1238 register_console(&zs_console);
1239
1240 return 0;
1241 }
1242
1243 console_initcall(zs_serial_console_init);
1244
1245 #define SERIAL_ZS_CONSOLE &zs_console
1246 #else
1247 #define SERIAL_ZS_CONSOLE NULL
1248 #endif /* CONFIG_SERIAL_ZS_CONSOLE */
1249
1250 static struct uart_driver zs_reg = {
1251 .owner = THIS_MODULE,
1252 .driver_name = "serial",
1253 .dev_name = "ttyS",
1254 .major = TTY_MAJOR,
1255 .minor = 64,
1256 .nr = ZS_NUM_SCCS * ZS_NUM_CHAN,
1257 .cons = SERIAL_ZS_CONSOLE,
1258 };
1259
1260 /* zs_init inits the driver. */
1261 static int __init zs_init(void)
1262 {
1263 int i, ret;
1264
1265 pr_info("%s%s\n", zs_name, zs_version);
1266
1267 /* Find out how many Z85C30 SCCs we have. */
1268 ret = zs_probe_sccs();
1269 if (ret)
1270 return ret;
1271
1272 ret = uart_register_driver(&zs_reg);
1273 if (ret)
1274 return ret;
1275
1276 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
1277 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1278 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1279 struct uart_port *uport = &zport->port;
1280
1281 if (zport->scc)
1282 uart_add_one_port(&zs_reg, uport);
1283 }
1284
1285 return 0;
1286 }
1287
1288 static void __exit zs_exit(void)
1289 {
1290 int i;
1291
1292 for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) {
1293 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1294 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1295 struct uart_port *uport = &zport->port;
1296
1297 if (zport->scc)
1298 uart_remove_one_port(&zs_reg, uport);
1299 }
1300
1301 uart_unregister_driver(&zs_reg);
1302 }
1303
1304 module_init(zs_init);
1305 module_exit(zs_exit);
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