aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/serial/zs.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/serial/zs.c')
-rw-r--r--drivers/serial/zs.c1287
1 files changed, 1287 insertions, 0 deletions
diff --git a/drivers/serial/zs.c b/drivers/serial/zs.c
new file mode 100644
index 000000000000..65f1294fd27b
--- /dev/null
+++ b/drivers/serial/zs.c
@@ -0,0 +1,1287 @@
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/major.h>
61#include <linux/serial.h>
62#include <linux/serial_core.h>
63#include <linux/spinlock.h>
64#include <linux/sysrq.h>
65#include <linux/tty.h>
66#include <linux/types.h>
67
68#include <asm/atomic.h>
69#include <asm/system.h>
70
71#include <asm/dec/interrupts.h>
72#include <asm/dec/ioasic_addrs.h>
73#include <asm/dec/system.h>
74
75#include "zs.h"
76
77
78MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
79MODULE_DESCRIPTION("DECstation Z85C30 serial driver");
80MODULE_LICENSE("GPL");
81
82
83static char zs_name[] __initdata = "DECstation Z85C30 serial driver version ";
84static char zs_version[] __initdata = "0.10";
85
86/*
87 * It would be nice to dynamically allocate everything that
88 * depends on ZS_NUM_SCCS, so we could support any number of
89 * Z85C30s, but for now...
90 */
91#define ZS_NUM_SCCS 2 /* Max # of ZS chips supported. */
92#define ZS_NUM_CHAN 2 /* 2 channels per chip. */
93#define ZS_CHAN_A 0 /* Index of the channel A. */
94#define ZS_CHAN_B 1 /* Index of the channel B. */
95#define ZS_CHAN_IO_SIZE 8 /* IOMEM space size. */
96#define ZS_CHAN_IO_STRIDE 4 /* Register alignment. */
97#define ZS_CHAN_IO_OFFSET 1 /* The SCC resides on the high byte
98 of the 16-bit IOBUS. */
99#define ZS_CLOCK 7372800 /* Z85C30 PCLK input clock rate. */
100
101#define to_zport(uport) container_of(uport, struct zs_port, port)
102
103struct zs_parms {
104 resource_size_t scc[ZS_NUM_SCCS];
105 int irq[ZS_NUM_SCCS];
106};
107
108static struct zs_scc zs_sccs[ZS_NUM_SCCS];
109
110static u8 zs_init_regs[ZS_NUM_REGS] __initdata = {
111 0, /* write 0 */
112 PAR_SPEC, /* write 1 */
113 0, /* write 2 */
114 0, /* write 3 */
115 X16CLK | SB1, /* write 4 */
116 0, /* write 5 */
117 0, 0, 0, /* write 6, 7, 8 */
118 MIE | DLC | NV, /* write 9 */
119 NRZ, /* write 10 */
120 TCBR | RCBR, /* write 11 */
121 0, 0, /* BRG time constant, write 12 + 13 */
122 BRSRC | BRENABL, /* write 14 */
123 0, /* write 15 */
124};
125
126/*
127 * Debugging.
128 */
129#undef ZS_DEBUG_REGS
130
131
132/*
133 * Reading and writing Z85C30 registers.
134 */
135static void recovery_delay(void)
136{
137 udelay(2);
138}
139
140static u8 read_zsreg(struct zs_port *zport, int reg)
141{
142 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
143 u8 retval;
144
145 if (reg != 0) {
146 writeb(reg & 0xf, control);
147 fast_iob();
148 recovery_delay();
149 }
150 retval = readb(control);
151 recovery_delay();
152 return retval;
153}
154
155static void write_zsreg(struct zs_port *zport, int reg, u8 value)
156{
157 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET;
158
159 if (reg != 0) {
160 writeb(reg & 0xf, control);
161 fast_iob(); recovery_delay();
162 }
163 writeb(value, control);
164 fast_iob();
165 recovery_delay();
166 return;
167}
168
169static u8 read_zsdata(struct zs_port *zport)
170{
171 void __iomem *data = zport->port.membase +
172 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
173 u8 retval;
174
175 retval = readb(data);
176 recovery_delay();
177 return retval;
178}
179
180static void write_zsdata(struct zs_port *zport, u8 value)
181{
182 void __iomem *data = zport->port.membase +
183 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET;
184
185 writeb(value, data);
186 fast_iob();
187 recovery_delay();
188 return;
189}
190
191#ifdef ZS_DEBUG_REGS
192void zs_dump(void)
193{
194 struct zs_port *zport;
195 int i, j;
196
197 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
198 zport = &zs_sccs[i / ZS_NUM_CHAN].zport[i % ZS_NUM_CHAN];
199
200 if (!zport->scc)
201 continue;
202
203 for (j = 0; j < 16; j++)
204 printk("W%-2d = 0x%02x\t", j, zport->regs[j]);
205 printk("\n");
206 for (j = 0; j < 16; j++)
207 printk("R%-2d = 0x%02x\t", j, read_zsreg(zport, j));
208 printk("\n\n");
209 }
210}
211#endif
212
213
214static void zs_spin_lock_cond_irq(spinlock_t *lock, int irq)
215{
216 if (irq)
217 spin_lock_irq(lock);
218 else
219 spin_lock(lock);
220}
221
222static void zs_spin_unlock_cond_irq(spinlock_t *lock, int irq)
223{
224 if (irq)
225 spin_unlock_irq(lock);
226 else
227 spin_unlock(lock);
228}
229
230static int zs_receive_drain(struct zs_port *zport)
231{
232 int loops = 10000;
233
234 while ((read_zsreg(zport, R0) & Rx_CH_AV) && loops--)
235 read_zsdata(zport);
236 return loops;
237}
238
239static int zs_transmit_drain(struct zs_port *zport, int irq)
240{
241 struct zs_scc *scc = zport->scc;
242 int loops = 10000;
243
244 while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && loops--) {
245 zs_spin_unlock_cond_irq(&scc->zlock, irq);
246 udelay(2);
247 zs_spin_lock_cond_irq(&scc->zlock, irq);
248 }
249 return loops;
250}
251
252static int zs_line_drain(struct zs_port *zport, int irq)
253{
254 struct zs_scc *scc = zport->scc;
255 int loops = 10000;
256
257 while (!(read_zsreg(zport, R1) & ALL_SNT) && loops--) {
258 zs_spin_unlock_cond_irq(&scc->zlock, irq);
259 udelay(2);
260 zs_spin_lock_cond_irq(&scc->zlock, irq);
261 }
262 return loops;
263}
264
265
266static void load_zsregs(struct zs_port *zport, u8 *regs, int irq)
267{
268 /* Let the current transmission finish. */
269 zs_line_drain(zport, irq);
270 /* Load 'em up. */
271 write_zsreg(zport, R3, regs[3] & ~RxENABLE);
272 write_zsreg(zport, R5, regs[5] & ~TxENAB);
273 write_zsreg(zport, R4, regs[4]);
274 write_zsreg(zport, R9, regs[9]);
275 write_zsreg(zport, R1, regs[1]);
276 write_zsreg(zport, R2, regs[2]);
277 write_zsreg(zport, R10, regs[10]);
278 write_zsreg(zport, R14, regs[14] & ~BRENABL);
279 write_zsreg(zport, R11, regs[11]);
280 write_zsreg(zport, R12, regs[12]);
281 write_zsreg(zport, R13, regs[13]);
282 write_zsreg(zport, R14, regs[14]);
283 write_zsreg(zport, R15, regs[15]);
284 if (regs[3] & RxENABLE)
285 write_zsreg(zport, R3, regs[3]);
286 if (regs[5] & TxENAB)
287 write_zsreg(zport, R5, regs[5]);
288 return;
289}
290
291
292/*
293 * Status handling routines.
294 */
295
296/*
297 * zs_tx_empty() -- get the transmitter empty status
298 *
299 * Purpose: Let user call ioctl() to get info when the UART physically
300 * is emptied. On bus types like RS485, the transmitter must
301 * release the bus after transmitting. This must be done when
302 * the transmit shift register is empty, not be done when the
303 * transmit holding register is empty. This functionality
304 * allows an RS485 driver to be written in user space.
305 */
306static unsigned int zs_tx_empty(struct uart_port *uport)
307{
308 struct zs_port *zport = to_zport(uport);
309 struct zs_scc *scc = zport->scc;
310 unsigned long flags;
311 u8 status;
312
313 spin_lock_irqsave(&scc->zlock, flags);
314 status = read_zsreg(zport, R1);
315 spin_unlock_irqrestore(&scc->zlock, flags);
316
317 return status & ALL_SNT ? TIOCSER_TEMT : 0;
318}
319
320static unsigned int zs_raw_get_ab_mctrl(struct zs_port *zport_a,
321 struct zs_port *zport_b)
322{
323 u8 status_a, status_b;
324 unsigned int mctrl;
325
326 status_a = read_zsreg(zport_a, R0);
327 status_b = read_zsreg(zport_b, R0);
328
329 mctrl = ((status_b & CTS) ? TIOCM_CTS : 0) |
330 ((status_b & DCD) ? TIOCM_CAR : 0) |
331 ((status_a & DCD) ? TIOCM_RNG : 0) |
332 ((status_a & SYNC_HUNT) ? TIOCM_DSR : 0);
333
334 return mctrl;
335}
336
337static unsigned int zs_raw_get_mctrl(struct zs_port *zport)
338{
339 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
340
341 return zport != zport_a ? zs_raw_get_ab_mctrl(zport_a, zport) : 0;
342}
343
344static unsigned int zs_raw_xor_mctrl(struct zs_port *zport)
345{
346 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A];
347 unsigned int mmask, mctrl, delta;
348 u8 mask_a, mask_b;
349
350 if (zport == zport_a)
351 return 0;
352
353 mask_a = zport_a->regs[15];
354 mask_b = zport->regs[15];
355
356 mmask = ((mask_b & CTSIE) ? TIOCM_CTS : 0) |
357 ((mask_b & DCDIE) ? TIOCM_CAR : 0) |
358 ((mask_a & DCDIE) ? TIOCM_RNG : 0) |
359 ((mask_a & SYNCIE) ? TIOCM_DSR : 0);
360
361 mctrl = zport->mctrl;
362 if (mmask) {
363 mctrl &= ~mmask;
364 mctrl |= zs_raw_get_ab_mctrl(zport_a, zport) & mmask;
365 }
366
367 delta = mctrl ^ zport->mctrl;
368 if (delta)
369 zport->mctrl = mctrl;
370
371 return delta;
372}
373
374static unsigned int zs_get_mctrl(struct uart_port *uport)
375{
376 struct zs_port *zport = to_zport(uport);
377 struct zs_scc *scc = zport->scc;
378 unsigned int mctrl;
379
380 spin_lock(&scc->zlock);
381 mctrl = zs_raw_get_mctrl(zport);
382 spin_unlock(&scc->zlock);
383
384 return mctrl;
385}
386
387static void zs_set_mctrl(struct uart_port *uport, unsigned int mctrl)
388{
389 struct zs_port *zport = to_zport(uport);
390 struct zs_scc *scc = zport->scc;
391 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
392 u8 oldloop, newloop;
393
394 spin_lock(&scc->zlock);
395 if (zport != zport_a) {
396 if (mctrl & TIOCM_DTR)
397 zport_a->regs[5] |= DTR;
398 else
399 zport_a->regs[5] &= ~DTR;
400 if (mctrl & TIOCM_RTS)
401 zport_a->regs[5] |= RTS;
402 else
403 zport_a->regs[5] &= ~RTS;
404 write_zsreg(zport_a, R5, zport_a->regs[5]);
405 }
406
407 /* Rarely modified, so don't poke at hardware unless necessary. */
408 oldloop = zport->regs[14];
409 newloop = oldloop;
410 if (mctrl & TIOCM_LOOP)
411 newloop |= LOOPBAK;
412 else
413 newloop &= ~LOOPBAK;
414 if (newloop != oldloop) {
415 zport->regs[14] = newloop;
416 write_zsreg(zport, R14, zport->regs[14]);
417 }
418 spin_unlock(&scc->zlock);
419}
420
421static void zs_raw_stop_tx(struct zs_port *zport)
422{
423 write_zsreg(zport, R0, RES_Tx_P);
424 zport->tx_stopped = 1;
425}
426
427static void zs_stop_tx(struct uart_port *uport)
428{
429 struct zs_port *zport = to_zport(uport);
430 struct zs_scc *scc = zport->scc;
431
432 spin_lock(&scc->zlock);
433 zs_raw_stop_tx(zport);
434 spin_unlock(&scc->zlock);
435}
436
437static void zs_raw_transmit_chars(struct zs_port *);
438
439static void zs_start_tx(struct uart_port *uport)
440{
441 struct zs_port *zport = to_zport(uport);
442 struct zs_scc *scc = zport->scc;
443
444 spin_lock(&scc->zlock);
445 if (zport->tx_stopped) {
446 zs_transmit_drain(zport, 0);
447 zport->tx_stopped = 0;
448 zs_raw_transmit_chars(zport);
449 }
450 spin_unlock(&scc->zlock);
451}
452
453static void zs_stop_rx(struct uart_port *uport)
454{
455 struct zs_port *zport = to_zport(uport);
456 struct zs_scc *scc = zport->scc;
457 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
458
459 spin_lock(&scc->zlock);
460 zport->regs[15] &= ~BRKIE;
461 zport->regs[1] &= ~(RxINT_MASK | TxINT_ENAB);
462 zport->regs[1] |= RxINT_DISAB;
463
464 if (zport != zport_a) {
465 /* A-side DCD tracks RI and SYNC tracks DSR. */
466 zport_a->regs[15] &= ~(DCDIE | SYNCIE);
467 write_zsreg(zport_a, R15, zport_a->regs[15]);
468 if (!(zport_a->regs[15] & BRKIE)) {
469 zport_a->regs[1] &= ~EXT_INT_ENAB;
470 write_zsreg(zport_a, R1, zport_a->regs[1]);
471 }
472
473 /* This-side DCD tracks DCD and CTS tracks CTS. */
474 zport->regs[15] &= ~(DCDIE | CTSIE);
475 zport->regs[1] &= ~EXT_INT_ENAB;
476 } else {
477 /* DCD tracks RI and SYNC tracks DSR for the B side. */
478 if (!(zport->regs[15] & (DCDIE | SYNCIE)))
479 zport->regs[1] &= ~EXT_INT_ENAB;
480 }
481
482 write_zsreg(zport, R15, zport->regs[15]);
483 write_zsreg(zport, R1, zport->regs[1]);
484 spin_unlock(&scc->zlock);
485}
486
487static void zs_enable_ms(struct uart_port *uport)
488{
489 struct zs_port *zport = to_zport(uport);
490 struct zs_scc *scc = zport->scc;
491 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
492
493 if (zport == zport_a)
494 return;
495
496 spin_lock(&scc->zlock);
497
498 /* Clear Ext interrupts if not being handled already. */
499 if (!(zport_a->regs[1] & EXT_INT_ENAB))
500 write_zsreg(zport_a, R0, RES_EXT_INT);
501
502 /* A-side DCD tracks RI and SYNC tracks DSR. */
503 zport_a->regs[1] |= EXT_INT_ENAB;
504 zport_a->regs[15] |= DCDIE | SYNCIE;
505
506 /* This-side DCD tracks DCD and CTS tracks CTS. */
507 zport->regs[15] |= DCDIE | CTSIE;
508
509 zs_raw_xor_mctrl(zport);
510
511 write_zsreg(zport_a, R1, zport_a->regs[1]);
512 write_zsreg(zport_a, R15, zport_a->regs[15]);
513 write_zsreg(zport, R15, zport->regs[15]);
514 spin_unlock(&scc->zlock);
515}
516
517static void zs_break_ctl(struct uart_port *uport, int break_state)
518{
519 struct zs_port *zport = to_zport(uport);
520 struct zs_scc *scc = zport->scc;
521 unsigned long flags;
522
523 spin_lock_irqsave(&scc->zlock, flags);
524 if (break_state == -1)
525 zport->regs[5] |= SND_BRK;
526 else
527 zport->regs[5] &= ~SND_BRK;
528 write_zsreg(zport, R5, zport->regs[5]);
529 spin_unlock_irqrestore(&scc->zlock, flags);
530}
531
532
533/*
534 * Interrupt handling routines.
535 */
536#define Rx_BRK 0x0100 /* BREAK event software flag. */
537#define Rx_SYS 0x0200 /* SysRq event software flag. */
538
539static void zs_receive_chars(struct zs_port *zport)
540{
541 struct uart_port *uport = &zport->port;
542 struct zs_scc *scc = zport->scc;
543 struct uart_icount *icount;
544 unsigned int avail, status, ch, flag;
545 int count;
546
547 for (count = 16; count; count--) {
548 spin_lock(&scc->zlock);
549 avail = read_zsreg(zport, R0) & Rx_CH_AV;
550 spin_unlock(&scc->zlock);
551 if (!avail)
552 break;
553
554 spin_lock(&scc->zlock);
555 status = read_zsreg(zport, R1) & (Rx_OVR | FRM_ERR | PAR_ERR);
556 ch = read_zsdata(zport);
557 spin_unlock(&scc->zlock);
558
559 flag = TTY_NORMAL;
560
561 icount = &uport->icount;
562 icount->rx++;
563
564 /* Handle the null char got when BREAK is removed. */
565 if (!ch)
566 status |= zport->tty_break;
567 if (unlikely(status &
568 (Rx_OVR | FRM_ERR | PAR_ERR | Rx_SYS | Rx_BRK))) {
569 zport->tty_break = 0;
570
571 /* Reset the error indication. */
572 if (status & (Rx_OVR | FRM_ERR | PAR_ERR)) {
573 spin_lock(&scc->zlock);
574 write_zsreg(zport, R0, ERR_RES);
575 spin_unlock(&scc->zlock);
576 }
577
578 if (status & (Rx_SYS | Rx_BRK)) {
579 icount->brk++;
580 /* SysRq discards the null char. */
581 if (status & Rx_SYS)
582 continue;
583 } else if (status & FRM_ERR)
584 icount->frame++;
585 else if (status & PAR_ERR)
586 icount->parity++;
587 if (status & Rx_OVR)
588 icount->overrun++;
589
590 status &= uport->read_status_mask;
591 if (status & Rx_BRK)
592 flag = TTY_BREAK;
593 else if (status & FRM_ERR)
594 flag = TTY_FRAME;
595 else if (status & PAR_ERR)
596 flag = TTY_PARITY;
597 }
598
599 if (uart_handle_sysrq_char(uport, ch))
600 continue;
601
602 uart_insert_char(uport, status, Rx_OVR, ch, flag);
603 }
604
605 tty_flip_buffer_push(uport->info->tty);
606}
607
608static void zs_raw_transmit_chars(struct zs_port *zport)
609{
610 struct circ_buf *xmit = &zport->port.info->xmit;
611
612 /* XON/XOFF chars. */
613 if (zport->port.x_char) {
614 write_zsdata(zport, zport->port.x_char);
615 zport->port.icount.tx++;
616 zport->port.x_char = 0;
617 return;
618 }
619
620 /* If nothing to do or stopped or hardware stopped. */
621 if (uart_circ_empty(xmit) || uart_tx_stopped(&zport->port)) {
622 zs_raw_stop_tx(zport);
623 return;
624 }
625
626 /* Send char. */
627 write_zsdata(zport, xmit->buf[xmit->tail]);
628 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
629 zport->port.icount.tx++;
630
631 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
632 uart_write_wakeup(&zport->port);
633
634 /* Are we are done? */
635 if (uart_circ_empty(xmit))
636 zs_raw_stop_tx(zport);
637}
638
639static void zs_transmit_chars(struct zs_port *zport)
640{
641 struct zs_scc *scc = zport->scc;
642
643 spin_lock(&scc->zlock);
644 zs_raw_transmit_chars(zport);
645 spin_unlock(&scc->zlock);
646}
647
648static void zs_status_handle(struct zs_port *zport, struct zs_port *zport_a)
649{
650 struct uart_port *uport = &zport->port;
651 struct zs_scc *scc = zport->scc;
652 unsigned int delta;
653 u8 status, brk;
654
655 spin_lock(&scc->zlock);
656
657 /* Get status from Read Register 0. */
658 status = read_zsreg(zport, R0);
659
660 if (zport->regs[15] & BRKIE) {
661 brk = status & BRK_ABRT;
662 if (brk && !zport->brk) {
663 spin_unlock(&scc->zlock);
664 if (uart_handle_break(uport))
665 zport->tty_break = Rx_SYS;
666 else
667 zport->tty_break = Rx_BRK;
668 spin_lock(&scc->zlock);
669 }
670 zport->brk = brk;
671 }
672
673 if (zport != zport_a) {
674 delta = zs_raw_xor_mctrl(zport);
675 spin_unlock(&scc->zlock);
676
677 if (delta & TIOCM_CTS)
678 uart_handle_cts_change(uport,
679 zport->mctrl & TIOCM_CTS);
680 if (delta & TIOCM_CAR)
681 uart_handle_dcd_change(uport,
682 zport->mctrl & TIOCM_CAR);
683 if (delta & TIOCM_RNG)
684 uport->icount.dsr++;
685 if (delta & TIOCM_DSR)
686 uport->icount.rng++;
687
688 if (delta)
689 wake_up_interruptible(&uport->info->delta_msr_wait);
690
691 spin_lock(&scc->zlock);
692 }
693
694 /* Clear the status condition... */
695 write_zsreg(zport, R0, RES_EXT_INT);
696
697 spin_unlock(&scc->zlock);
698}
699
700/*
701 * This is the Z85C30 driver's generic interrupt routine.
702 */
703static irqreturn_t zs_interrupt(int irq, void *dev_id)
704{
705 struct zs_scc *scc = dev_id;
706 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
707 struct zs_port *zport_b = &scc->zport[ZS_CHAN_B];
708 irqreturn_t status = IRQ_NONE;
709 u8 zs_intreg;
710 int count;
711
712 /*
713 * NOTE: The read register 3, which holds the irq status,
714 * does so for both channels on each chip. Although
715 * the status value itself must be read from the A
716 * channel and is only valid when read from channel A.
717 * Yes... broken hardware...
718 */
719 for (count = 16; count; count--) {
720 spin_lock(&scc->zlock);
721 zs_intreg = read_zsreg(zport_a, R3);
722 spin_unlock(&scc->zlock);
723 if (!zs_intreg)
724 break;
725
726 /*
727 * We do not like losing characters, so we prioritise
728 * interrupt sources a little bit differently than
729 * the SCC would, was it allowed to.
730 */
731 if (zs_intreg & CHBRxIP)
732 zs_receive_chars(zport_b);
733 if (zs_intreg & CHARxIP)
734 zs_receive_chars(zport_a);
735 if (zs_intreg & CHBEXT)
736 zs_status_handle(zport_b, zport_a);
737 if (zs_intreg & CHAEXT)
738 zs_status_handle(zport_a, zport_a);
739 if (zs_intreg & CHBTxIP)
740 zs_transmit_chars(zport_b);
741 if (zs_intreg & CHATxIP)
742 zs_transmit_chars(zport_a);
743
744 status = IRQ_HANDLED;
745 }
746
747 return status;
748}
749
750
751/*
752 * Finally, routines used to initialize the serial port.
753 */
754static int zs_startup(struct uart_port *uport)
755{
756 struct zs_port *zport = to_zport(uport);
757 struct zs_scc *scc = zport->scc;
758 unsigned long flags;
759 int irq_guard;
760 int ret;
761
762 irq_guard = atomic_add_return(1, &scc->irq_guard);
763 if (irq_guard == 1) {
764 ret = request_irq(zport->port.irq, zs_interrupt,
765 IRQF_SHARED, "scc", scc);
766 if (ret) {
767 atomic_add(-1, &scc->irq_guard);
768 printk(KERN_ERR "zs: can't get irq %d\n",
769 zport->port.irq);
770 return ret;
771 }
772 }
773
774 spin_lock_irqsave(&scc->zlock, flags);
775
776 /* Clear the receive FIFO. */
777 zs_receive_drain(zport);
778
779 /* Clear the interrupt registers. */
780 write_zsreg(zport, R0, ERR_RES);
781 write_zsreg(zport, R0, RES_Tx_P);
782 /* But Ext only if not being handled already. */
783 if (!(zport->regs[1] & EXT_INT_ENAB))
784 write_zsreg(zport, R0, RES_EXT_INT);
785
786 /* Finally, enable sequencing and interrupts. */
787 zport->regs[1] &= ~RxINT_MASK;
788 zport->regs[1] |= RxINT_ALL | TxINT_ENAB | EXT_INT_ENAB;
789 zport->regs[3] |= RxENABLE;
790 zport->regs[5] |= TxENAB;
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
808static 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[5] &= ~TxENAB;
818 zport->regs[3] &= ~RxENABLE;
819 write_zsreg(zport, R5, zport->regs[5]);
820 write_zsreg(zport, R3, zport->regs[3]);
821
822 spin_unlock_irqrestore(&scc->zlock, flags);
823
824 irq_guard = atomic_add_return(-1, &scc->irq_guard);
825 if (!irq_guard)
826 free_irq(zport->port.irq, scc);
827}
828
829
830static void zs_reset(struct zs_port *zport)
831{
832 struct zs_scc *scc = zport->scc;
833 int irq;
834 unsigned long flags;
835
836 spin_lock_irqsave(&scc->zlock, flags);
837 irq = !irqs_disabled_flags(flags);
838 if (!scc->initialised) {
839 /* Reset the pointer first, just in case... */
840 read_zsreg(zport, R0);
841 /* And let the current transmission finish. */
842 zs_line_drain(zport, irq);
843 write_zsreg(zport, R9, FHWRES);
844 udelay(10);
845 write_zsreg(zport, R9, 0);
846 scc->initialised = 1;
847 }
848 load_zsregs(zport, zport->regs, irq);
849 spin_unlock_irqrestore(&scc->zlock, flags);
850}
851
852static void zs_set_termios(struct uart_port *uport, struct ktermios *termios,
853 struct ktermios *old_termios)
854{
855 struct zs_port *zport = to_zport(uport);
856 struct zs_scc *scc = zport->scc;
857 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
858 int irq;
859 unsigned int baud, brg;
860 unsigned long flags;
861
862 spin_lock_irqsave(&scc->zlock, flags);
863 irq = !irqs_disabled_flags(flags);
864
865 /* Byte size. */
866 zport->regs[3] &= ~RxNBITS_MASK;
867 zport->regs[5] &= ~TxNBITS_MASK;
868 switch (termios->c_cflag & CSIZE) {
869 case CS5:
870 zport->regs[3] |= Rx5;
871 zport->regs[5] |= Tx5;
872 break;
873 case CS6:
874 zport->regs[3] |= Rx6;
875 zport->regs[5] |= Tx6;
876 break;
877 case CS7:
878 zport->regs[3] |= Rx7;
879 zport->regs[5] |= Tx7;
880 break;
881 case CS8:
882 default:
883 zport->regs[3] |= Rx8;
884 zport->regs[5] |= Tx8;
885 break;
886 }
887
888 /* Parity and stop bits. */
889 zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN);
890 if (termios->c_cflag & CSTOPB)
891 zport->regs[4] |= SB2;
892 else
893 zport->regs[4] |= SB1;
894 if (termios->c_cflag & PARENB)
895 zport->regs[4] |= PAR_ENA;
896 if (!(termios->c_cflag & PARODD))
897 zport->regs[4] |= PAR_EVEN;
898 switch (zport->clk_mode) {
899 case 64:
900 zport->regs[4] |= X64CLK;
901 break;
902 case 32:
903 zport->regs[4] |= X32CLK;
904 break;
905 case 16:
906 zport->regs[4] |= X16CLK;
907 break;
908 case 1:
909 zport->regs[4] |= X1CLK;
910 break;
911 default:
912 BUG();
913 }
914
915 baud = uart_get_baud_rate(uport, termios, old_termios, 0,
916 uport->uartclk / zport->clk_mode / 4);
917
918 brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode);
919 zport->regs[12] = brg & 0xff;
920 zport->regs[13] = (brg >> 8) & 0xff;
921
922 uart_update_timeout(uport, termios->c_cflag, baud);
923
924 uport->read_status_mask = Rx_OVR;
925 if (termios->c_iflag & INPCK)
926 uport->read_status_mask |= FRM_ERR | PAR_ERR;
927 if (termios->c_iflag & (BRKINT | PARMRK))
928 uport->read_status_mask |= Rx_BRK;
929
930 uport->ignore_status_mask = 0;
931 if (termios->c_iflag & IGNPAR)
932 uport->ignore_status_mask |= FRM_ERR | PAR_ERR;
933 if (termios->c_iflag & IGNBRK) {
934 uport->ignore_status_mask |= Rx_BRK;
935 if (termios->c_iflag & IGNPAR)
936 uport->ignore_status_mask |= Rx_OVR;
937 }
938
939 if (termios->c_cflag & CREAD)
940 zport->regs[3] |= RxENABLE;
941 else
942 zport->regs[3] &= ~RxENABLE;
943
944 if (zport != zport_a) {
945 if (!(termios->c_cflag & CLOCAL)) {
946 zport->regs[15] |= DCDIE;
947 } else
948 zport->regs[15] &= ~DCDIE;
949 if (termios->c_cflag & CRTSCTS) {
950 zport->regs[15] |= CTSIE;
951 } else
952 zport->regs[15] &= ~CTSIE;
953 zs_raw_xor_mctrl(zport);
954 }
955
956 /* Load up the new values. */
957 load_zsregs(zport, zport->regs, irq);
958
959 spin_unlock_irqrestore(&scc->zlock, flags);
960}
961
962
963static const char *zs_type(struct uart_port *uport)
964{
965 return "Z85C30 SCC";
966}
967
968static void zs_release_port(struct uart_port *uport)
969{
970 iounmap(uport->membase);
971 uport->membase = 0;
972 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
973}
974
975static int zs_map_port(struct uart_port *uport)
976{
977 if (!uport->membase)
978 uport->membase = ioremap_nocache(uport->mapbase,
979 ZS_CHAN_IO_SIZE);
980 if (!uport->membase) {
981 printk(KERN_ERR "zs: Cannot map MMIO\n");
982 return -ENOMEM;
983 }
984 return 0;
985}
986
987static int zs_request_port(struct uart_port *uport)
988{
989 int ret;
990
991 if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) {
992 printk(KERN_ERR "zs: Unable to reserve MMIO resource\n");
993 return -EBUSY;
994 }
995 ret = zs_map_port(uport);
996 if (ret) {
997 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
998 return ret;
999 }
1000 return 0;
1001}
1002
1003static void zs_config_port(struct uart_port *uport, int flags)
1004{
1005 struct zs_port *zport = to_zport(uport);
1006
1007 if (flags & UART_CONFIG_TYPE) {
1008 if (zs_request_port(uport))
1009 return;
1010
1011 uport->type = PORT_ZS;
1012
1013 zs_reset(zport);
1014 }
1015}
1016
1017static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser)
1018{
1019 struct zs_port *zport = to_zport(uport);
1020 int ret = 0;
1021
1022 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS)
1023 ret = -EINVAL;
1024 if (ser->irq != uport->irq)
1025 ret = -EINVAL;
1026 if (ser->baud_base != uport->uartclk / zport->clk_mode / 4)
1027 ret = -EINVAL;
1028 return ret;
1029}
1030
1031
1032static struct uart_ops zs_ops = {
1033 .tx_empty = zs_tx_empty,
1034 .set_mctrl = zs_set_mctrl,
1035 .get_mctrl = zs_get_mctrl,
1036 .stop_tx = zs_stop_tx,
1037 .start_tx = zs_start_tx,
1038 .stop_rx = zs_stop_rx,
1039 .enable_ms = zs_enable_ms,
1040 .break_ctl = zs_break_ctl,
1041 .startup = zs_startup,
1042 .shutdown = zs_shutdown,
1043 .set_termios = zs_set_termios,
1044 .type = zs_type,
1045 .release_port = zs_release_port,
1046 .request_port = zs_request_port,
1047 .config_port = zs_config_port,
1048 .verify_port = zs_verify_port,
1049};
1050
1051/*
1052 * Initialize Z85C30 port structures.
1053 */
1054static int __init zs_probe_sccs(void)
1055{
1056 static int probed;
1057 struct zs_parms zs_parms;
1058 int chip, side, irq;
1059 int n_chips = 0;
1060 int i;
1061
1062 if (probed)
1063 return 0;
1064
1065 irq = dec_interrupt[DEC_IRQ_SCC0];
1066 if (irq >= 0) {
1067 zs_parms.scc[n_chips] = IOASIC_SCC0;
1068 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0];
1069 n_chips++;
1070 }
1071 irq = dec_interrupt[DEC_IRQ_SCC1];
1072 if (irq >= 0) {
1073 zs_parms.scc[n_chips] = IOASIC_SCC1;
1074 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1];
1075 n_chips++;
1076 }
1077 if (!n_chips)
1078 return -ENXIO;
1079
1080 probed = 1;
1081
1082 for (chip = 0; chip < n_chips; chip++) {
1083 spin_lock_init(&zs_sccs[chip].zlock);
1084 for (side = 0; side < ZS_NUM_CHAN; side++) {
1085 struct zs_port *zport = &zs_sccs[chip].zport[side];
1086 struct uart_port *uport = &zport->port;
1087
1088 zport->scc = &zs_sccs[chip];
1089 zport->clk_mode = 16;
1090
1091 uport->irq = zs_parms.irq[chip];
1092 uport->uartclk = ZS_CLOCK;
1093 uport->fifosize = 1;
1094 uport->iotype = UPIO_MEM;
1095 uport->flags = UPF_BOOT_AUTOCONF;
1096 uport->ops = &zs_ops;
1097 uport->line = chip * ZS_NUM_CHAN + side;
1098 uport->mapbase = dec_kn_slot_base +
1099 zs_parms.scc[chip] +
1100 (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE;
1101
1102 for (i = 0; i < ZS_NUM_REGS; i++)
1103 zport->regs[i] = zs_init_regs[i];
1104 }
1105 }
1106
1107 return 0;
1108}
1109
1110
1111#ifdef CONFIG_SERIAL_ZS_CONSOLE
1112static void zs_console_putchar(struct uart_port *uport, int ch)
1113{
1114 struct zs_port *zport = to_zport(uport);
1115 struct zs_scc *scc = zport->scc;
1116 int irq;
1117 unsigned long flags;
1118
1119 spin_lock_irqsave(&scc->zlock, flags);
1120 irq = !irqs_disabled_flags(flags);
1121 if (zs_transmit_drain(zport, irq))
1122 write_zsdata(zport, ch);
1123 spin_unlock_irqrestore(&scc->zlock, flags);
1124}
1125
1126/*
1127 * Print a string to the serial port trying not to disturb
1128 * any possible real use of the port...
1129 */
1130static void zs_console_write(struct console *co, const char *s,
1131 unsigned int count)
1132{
1133 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1134 struct zs_port *zport = &zs_sccs[chip].zport[side];
1135 struct zs_scc *scc = zport->scc;
1136 unsigned long flags;
1137 u8 txint, txenb;
1138 int irq;
1139
1140 /* Disable transmit interrupts and enable the transmitter. */
1141 spin_lock_irqsave(&scc->zlock, flags);
1142 txint = zport->regs[1];
1143 txenb = zport->regs[5];
1144 if (txint & TxINT_ENAB) {
1145 zport->regs[1] = txint & ~TxINT_ENAB;
1146 write_zsreg(zport, R1, zport->regs[1]);
1147 }
1148 if (!(txenb & TxENAB)) {
1149 zport->regs[5] = txenb | TxENAB;
1150 write_zsreg(zport, R5, zport->regs[5]);
1151 }
1152 spin_unlock_irqrestore(&scc->zlock, flags);
1153
1154 uart_console_write(&zport->port, s, count, zs_console_putchar);
1155
1156 /* Restore transmit interrupts and the transmitter enable. */
1157 spin_lock_irqsave(&scc->zlock, flags);
1158 irq = !irqs_disabled_flags(flags);
1159 zs_line_drain(zport, irq);
1160 if (!(txenb & TxENAB)) {
1161 zport->regs[5] &= ~TxENAB;
1162 write_zsreg(zport, R5, zport->regs[5]);
1163 }
1164 if (txint & TxINT_ENAB) {
1165 zport->regs[1] |= TxINT_ENAB;
1166 write_zsreg(zport, R1, zport->regs[1]);
1167 }
1168 spin_unlock_irqrestore(&scc->zlock, flags);
1169}
1170
1171/*
1172 * Setup serial console baud/bits/parity. We do two things here:
1173 * - construct a cflag setting for the first uart_open()
1174 * - initialise the serial port
1175 * Return non-zero if we didn't find a serial port.
1176 */
1177static int __init zs_console_setup(struct console *co, char *options)
1178{
1179 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1180 struct zs_port *zport = &zs_sccs[chip].zport[side];
1181 struct uart_port *uport = &zport->port;
1182 int baud = 9600;
1183 int bits = 8;
1184 int parity = 'n';
1185 int flow = 'n';
1186 int ret;
1187
1188 ret = zs_map_port(uport);
1189 if (ret)
1190 return ret;
1191
1192 zs_reset(zport);
1193
1194 if (options)
1195 uart_parse_options(options, &baud, &parity, &bits, &flow);
1196 return uart_set_options(uport, co, baud, parity, bits, flow);
1197}
1198
1199static struct uart_driver zs_reg;
1200static struct console zs_console = {
1201 .name = "ttyS",
1202 .write = zs_console_write,
1203 .device = uart_console_device,
1204 .setup = zs_console_setup,
1205 .flags = CON_PRINTBUFFER,
1206 .index = -1,
1207 .data = &zs_reg,
1208};
1209
1210/*
1211 * Register console.
1212 */
1213static int __init zs_serial_console_init(void)
1214{
1215 int ret;
1216
1217 ret = zs_probe_sccs();
1218 if (ret)
1219 return ret;
1220 register_console(&zs_console);
1221
1222 return 0;
1223}
1224
1225console_initcall(zs_serial_console_init);
1226
1227#define SERIAL_ZS_CONSOLE &zs_console
1228#else
1229#define SERIAL_ZS_CONSOLE NULL
1230#endif /* CONFIG_SERIAL_ZS_CONSOLE */
1231
1232static struct uart_driver zs_reg = {
1233 .owner = THIS_MODULE,
1234 .driver_name = "serial",
1235 .dev_name = "ttyS",
1236 .major = TTY_MAJOR,
1237 .minor = 64,
1238 .nr = ZS_NUM_SCCS * ZS_NUM_CHAN,
1239 .cons = SERIAL_ZS_CONSOLE,
1240};
1241
1242/* zs_init inits the driver. */
1243static int __init zs_init(void)
1244{
1245 int i, ret;
1246
1247 pr_info("%s%s\n", zs_name, zs_version);
1248
1249 /* Find out how many Z85C30 SCCs we have. */
1250 ret = zs_probe_sccs();
1251 if (ret)
1252 return ret;
1253
1254 ret = uart_register_driver(&zs_reg);
1255 if (ret)
1256 return ret;
1257
1258 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
1259 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1260 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1261 struct uart_port *uport = &zport->port;
1262
1263 if (zport->scc)
1264 uart_add_one_port(&zs_reg, uport);
1265 }
1266
1267 return 0;
1268}
1269
1270static void __exit zs_exit(void)
1271{
1272 int i;
1273
1274 for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) {
1275 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1276 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1277 struct uart_port *uport = &zport->port;
1278
1279 if (zport->scc)
1280 uart_remove_one_port(&zs_reg, uport);
1281 }
1282
1283 uart_unregister_driver(&zs_reg);
1284}
1285
1286module_init(zs_init);
1287module_exit(zs_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-29 18:31:37 -0500