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writeback: split writeback_inodes_wb
[linux-2.6/next.git] / drivers / serial / zs.c
blob1a7fd3e703155b68ec98c11276730d8a361b8f80
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
78 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
79 MODULE_DESCRIPTION("DECstation Z85C30 serial driver");
80 MODULE_LICENSE("GPL");
81
82
83 static char zs_name[] __initdata = "DECstation Z85C30 serial driver version ";
84 static 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
103 struct zs_parms {
104 resource_size_t scc[ZS_NUM_SCCS];
105 int irq[ZS_NUM_SCCS];
106 };
107
108 static struct zs_scc zs_sccs[ZS_NUM_SCCS];
109
110 static 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 */
135 static void recovery_delay(void)
136 {
137 udelay(2);
138 }
139
140 static 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
155 static 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
169 static 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
180 static 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
192 void 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
214 static 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
222 static 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
230 static 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
239 static 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
252 static 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
266 static 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 */
306 static 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
320 static 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
337 static 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
344 static 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
374 static 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
387 static 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
421 static 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
427 static 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
437 static void zs_raw_transmit_chars(struct zs_port *);
438
439 static 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
453 static 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
487 static 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
517 static 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
539 static 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->state->port.tty);
606 }
607
608 static void zs_raw_transmit_chars(struct zs_port *zport)
609 {
610 struct circ_buf *xmit = &zport->port.state->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
639 static 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
648 static 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->state->port.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 */
703 static 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 */
754 static 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[15] |= BRKIE;
791 write_zsreg(zport, R1, zport->regs[1]);
792 write_zsreg(zport, R3, zport->regs[3]);
793 write_zsreg(zport, R5, zport->regs[5]);
794 write_zsreg(zport, R15, zport->regs[15]);
795
796 /* Record the current state of RR0. */
797 zport->mctrl = zs_raw_get_mctrl(zport);
798 zport->brk = read_zsreg(zport, R0) & BRK_ABRT;
799
800 zport->tx_stopped = 1;
801
802 spin_unlock_irqrestore(&scc->zlock, flags);
803
804 return 0;
805 }
806
807 static void zs_shutdown(struct uart_port *uport)
808 {
809 struct zs_port *zport = to_zport(uport);
810 struct zs_scc *scc = zport->scc;
811 unsigned long flags;
812 int irq_guard;
813
814 spin_lock_irqsave(&scc->zlock, flags);
815
816 zport->regs[3] &= ~RxENABLE;
817 write_zsreg(zport, R5, zport->regs[5]);
818 write_zsreg(zport, R3, zport->regs[3]);
819
820 spin_unlock_irqrestore(&scc->zlock, flags);
821
822 irq_guard = atomic_add_return(-1, &scc->irq_guard);
823 if (!irq_guard)
824 free_irq(zport->port.irq, scc);
825 }
826
827
828 static void zs_reset(struct zs_port *zport)
829 {
830 struct zs_scc *scc = zport->scc;
831 int irq;
832 unsigned long flags;
833
834 spin_lock_irqsave(&scc->zlock, flags);
835 irq = !irqs_disabled_flags(flags);
836 if (!scc->initialised) {
837 /* Reset the pointer first, just in case... */
838 read_zsreg(zport, R0);
839 /* And let the current transmission finish. */
840 zs_line_drain(zport, irq);
841 write_zsreg(zport, R9, FHWRES);
842 udelay(10);
843 write_zsreg(zport, R9, 0);
844 scc->initialised = 1;
845 }
846 load_zsregs(zport, zport->regs, irq);
847 spin_unlock_irqrestore(&scc->zlock, flags);
848 }
849
850 static void zs_set_termios(struct uart_port *uport, struct ktermios *termios,
851 struct ktermios *old_termios)
852 {
853 struct zs_port *zport = to_zport(uport);
854 struct zs_scc *scc = zport->scc;
855 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A];
856 int irq;
857 unsigned int baud, brg;
858 unsigned long flags;
859
860 spin_lock_irqsave(&scc->zlock, flags);
861 irq = !irqs_disabled_flags(flags);
862
863 /* Byte size. */
864 zport->regs[3] &= ~RxNBITS_MASK;
865 zport->regs[5] &= ~TxNBITS_MASK;
866 switch (termios->c_cflag & CSIZE) {
867 case CS5:
868 zport->regs[3] |= Rx5;
869 zport->regs[5] |= Tx5;
870 break;
871 case CS6:
872 zport->regs[3] |= Rx6;
873 zport->regs[5] |= Tx6;
874 break;
875 case CS7:
876 zport->regs[3] |= Rx7;
877 zport->regs[5] |= Tx7;
878 break;
879 case CS8:
880 default:
881 zport->regs[3] |= Rx8;
882 zport->regs[5] |= Tx8;
883 break;
884 }
885
886 /* Parity and stop bits. */
887 zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN);
888 if (termios->c_cflag & CSTOPB)
889 zport->regs[4] |= SB2;
890 else
891 zport->regs[4] |= SB1;
892 if (termios->c_cflag & PARENB)
893 zport->regs[4] |= PAR_ENA;
894 if (!(termios->c_cflag & PARODD))
895 zport->regs[4] |= PAR_EVEN;
896 switch (zport->clk_mode) {
897 case 64:
898 zport->regs[4] |= X64CLK;
899 break;
900 case 32:
901 zport->regs[4] |= X32CLK;
902 break;
903 case 16:
904 zport->regs[4] |= X16CLK;
905 break;
906 case 1:
907 zport->regs[4] |= X1CLK;
908 break;
909 default:
910 BUG();
911 }
912
913 baud = uart_get_baud_rate(uport, termios, old_termios, 0,
914 uport->uartclk / zport->clk_mode / 4);
915
916 brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode);
917 zport->regs[12] = brg & 0xff;
918 zport->regs[13] = (brg >> 8) & 0xff;
919
920 uart_update_timeout(uport, termios->c_cflag, baud);
921
922 uport->read_status_mask = Rx_OVR;
923 if (termios->c_iflag & INPCK)
924 uport->read_status_mask |= FRM_ERR | PAR_ERR;
925 if (termios->c_iflag & (BRKINT | PARMRK))
926 uport->read_status_mask |= Rx_BRK;
927
928 uport->ignore_status_mask = 0;
929 if (termios->c_iflag & IGNPAR)
930 uport->ignore_status_mask |= FRM_ERR | PAR_ERR;
931 if (termios->c_iflag & IGNBRK) {
932 uport->ignore_status_mask |= Rx_BRK;
933 if (termios->c_iflag & IGNPAR)
934 uport->ignore_status_mask |= Rx_OVR;
935 }
936
937 if (termios->c_cflag & CREAD)
938 zport->regs[3] |= RxENABLE;
939 else
940 zport->regs[3] &= ~RxENABLE;
941
942 if (zport != zport_a) {
943 if (!(termios->c_cflag & CLOCAL)) {
944 zport->regs[15] |= DCDIE;
945 } else
946 zport->regs[15] &= ~DCDIE;
947 if (termios->c_cflag & CRTSCTS) {
948 zport->regs[15] |= CTSIE;
949 } else
950 zport->regs[15] &= ~CTSIE;
951 zs_raw_xor_mctrl(zport);
952 }
953
954 /* Load up the new values. */
955 load_zsregs(zport, zport->regs, irq);
956
957 spin_unlock_irqrestore(&scc->zlock, flags);
958 }
959
960 /*
961 * Hack alert!
962 * Required solely so that the initial PROM-based console
963 * works undisturbed in parallel with this one.
964 */
965 static void zs_pm(struct uart_port *uport, unsigned int state,
966 unsigned int oldstate)
967 {
968 struct zs_port *zport = to_zport(uport);
969
970 if (state < 3)
971 zport->regs[5] |= TxENAB;
972 else
973 zport->regs[5] &= ~TxENAB;
974 write_zsreg(zport, R5, zport->regs[5]);
975 }
976
977
978 static const char *zs_type(struct uart_port *uport)
979 {
980 return "Z85C30 SCC";
981 }
982
983 static void zs_release_port(struct uart_port *uport)
984 {
985 iounmap(uport->membase);
986 uport->membase = 0;
987 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
988 }
989
990 static int zs_map_port(struct uart_port *uport)
991 {
992 if (!uport->membase)
993 uport->membase = ioremap_nocache(uport->mapbase,
994 ZS_CHAN_IO_SIZE);
995 if (!uport->membase) {
996 printk(KERN_ERR "zs: Cannot map MMIO\n");
997 return -ENOMEM;
998 }
999 return 0;
1000 }
1001
1002 static int zs_request_port(struct uart_port *uport)
1003 {
1004 int ret;
1005
1006 if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) {
1007 printk(KERN_ERR "zs: Unable to reserve MMIO resource\n");
1008 return -EBUSY;
1009 }
1010 ret = zs_map_port(uport);
1011 if (ret) {
1012 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE);
1013 return ret;
1014 }
1015 return 0;
1016 }
1017
1018 static void zs_config_port(struct uart_port *uport, int flags)
1019 {
1020 struct zs_port *zport = to_zport(uport);
1021
1022 if (flags & UART_CONFIG_TYPE) {
1023 if (zs_request_port(uport))
1024 return;
1025
1026 uport->type = PORT_ZS;
1027
1028 zs_reset(zport);
1029 }
1030 }
1031
1032 static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser)
1033 {
1034 struct zs_port *zport = to_zport(uport);
1035 int ret = 0;
1036
1037 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS)
1038 ret = -EINVAL;
1039 if (ser->irq != uport->irq)
1040 ret = -EINVAL;
1041 if (ser->baud_base != uport->uartclk / zport->clk_mode / 4)
1042 ret = -EINVAL;
1043 return ret;
1044 }
1045
1046
1047 static struct uart_ops zs_ops = {
1048 .tx_empty = zs_tx_empty,
1049 .set_mctrl = zs_set_mctrl,
1050 .get_mctrl = zs_get_mctrl,
1051 .stop_tx = zs_stop_tx,
1052 .start_tx = zs_start_tx,
1053 .stop_rx = zs_stop_rx,
1054 .enable_ms = zs_enable_ms,
1055 .break_ctl = zs_break_ctl,
1056 .startup = zs_startup,
1057 .shutdown = zs_shutdown,
1058 .set_termios = zs_set_termios,
1059 .pm = zs_pm,
1060 .type = zs_type,
1061 .release_port = zs_release_port,
1062 .request_port = zs_request_port,
1063 .config_port = zs_config_port,
1064 .verify_port = zs_verify_port,
1065 };
1066
1067 /*
1068 * Initialize Z85C30 port structures.
1069 */
1070 static int __init zs_probe_sccs(void)
1071 {
1072 static int probed;
1073 struct zs_parms zs_parms;
1074 int chip, side, irq;
1075 int n_chips = 0;
1076 int i;
1077
1078 if (probed)
1079 return 0;
1080
1081 irq = dec_interrupt[DEC_IRQ_SCC0];
1082 if (irq >= 0) {
1083 zs_parms.scc[n_chips] = IOASIC_SCC0;
1084 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0];
1085 n_chips++;
1086 }
1087 irq = dec_interrupt[DEC_IRQ_SCC1];
1088 if (irq >= 0) {
1089 zs_parms.scc[n_chips] = IOASIC_SCC1;
1090 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1];
1091 n_chips++;
1092 }
1093 if (!n_chips)
1094 return -ENXIO;
1095
1096 probed = 1;
1097
1098 for (chip = 0; chip < n_chips; chip++) {
1099 spin_lock_init(&zs_sccs[chip].zlock);
1100 for (side = 0; side < ZS_NUM_CHAN; side++) {
1101 struct zs_port *zport = &zs_sccs[chip].zport[side];
1102 struct uart_port *uport = &zport->port;
1103
1104 zport->scc = &zs_sccs[chip];
1105 zport->clk_mode = 16;
1106
1107 uport->irq = zs_parms.irq[chip];
1108 uport->uartclk = ZS_CLOCK;
1109 uport->fifosize = 1;
1110 uport->iotype = UPIO_MEM;
1111 uport->flags = UPF_BOOT_AUTOCONF;
1112 uport->ops = &zs_ops;
1113 uport->line = chip * ZS_NUM_CHAN + side;
1114 uport->mapbase = dec_kn_slot_base +
1115 zs_parms.scc[chip] +
1116 (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE;
1117
1118 for (i = 0; i < ZS_NUM_REGS; i++)
1119 zport->regs[i] = zs_init_regs[i];
1120 }
1121 }
1122
1123 return 0;
1124 }
1125
1126
1127 #ifdef CONFIG_SERIAL_ZS_CONSOLE
1128 static void zs_console_putchar(struct uart_port *uport, int ch)
1129 {
1130 struct zs_port *zport = to_zport(uport);
1131 struct zs_scc *scc = zport->scc;
1132 int irq;
1133 unsigned long flags;
1134
1135 spin_lock_irqsave(&scc->zlock, flags);
1136 irq = !irqs_disabled_flags(flags);
1137 if (zs_transmit_drain(zport, irq))
1138 write_zsdata(zport, ch);
1139 spin_unlock_irqrestore(&scc->zlock, flags);
1140 }
1141
1142 /*
1143 * Print a string to the serial port trying not to disturb
1144 * any possible real use of the port...
1145 */
1146 static void zs_console_write(struct console *co, const char *s,
1147 unsigned int count)
1148 {
1149 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1150 struct zs_port *zport = &zs_sccs[chip].zport[side];
1151 struct zs_scc *scc = zport->scc;
1152 unsigned long flags;
1153 u8 txint, txenb;
1154 int irq;
1155
1156 /* Disable transmit interrupts and enable the transmitter. */
1157 spin_lock_irqsave(&scc->zlock, flags);
1158 txint = zport->regs[1];
1159 txenb = zport->regs[5];
1160 if (txint & TxINT_ENAB) {
1161 zport->regs[1] = txint & ~TxINT_ENAB;
1162 write_zsreg(zport, R1, zport->regs[1]);
1163 }
1164 if (!(txenb & TxENAB)) {
1165 zport->regs[5] = txenb | TxENAB;
1166 write_zsreg(zport, R5, zport->regs[5]);
1167 }
1168 spin_unlock_irqrestore(&scc->zlock, flags);
1169
1170 uart_console_write(&zport->port, s, count, zs_console_putchar);
1171
1172 /* Restore transmit interrupts and the transmitter enable. */
1173 spin_lock_irqsave(&scc->zlock, flags);
1174 irq = !irqs_disabled_flags(flags);
1175 zs_line_drain(zport, irq);
1176 if (!(txenb & TxENAB)) {
1177 zport->regs[5] &= ~TxENAB;
1178 write_zsreg(zport, R5, zport->regs[5]);
1179 }
1180 if (txint & TxINT_ENAB) {
1181 zport->regs[1] |= TxINT_ENAB;
1182 write_zsreg(zport, R1, zport->regs[1]);
1183 }
1184 spin_unlock_irqrestore(&scc->zlock, flags);
1185 }
1186
1187 /*
1188 * Setup serial console baud/bits/parity. We do two things here:
1189 * - construct a cflag setting for the first uart_open()
1190 * - initialise the serial port
1191 * Return non-zero if we didn't find a serial port.
1192 */
1193 static int __init zs_console_setup(struct console *co, char *options)
1194 {
1195 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN;
1196 struct zs_port *zport = &zs_sccs[chip].zport[side];
1197 struct uart_port *uport = &zport->port;
1198 int baud = 9600;
1199 int bits = 8;
1200 int parity = 'n';
1201 int flow = 'n';
1202 int ret;
1203
1204 ret = zs_map_port(uport);
1205 if (ret)
1206 return ret;
1207
1208 zs_reset(zport);
1209 zs_pm(uport, 0, -1);
1210
1211 if (options)
1212 uart_parse_options(options, &baud, &parity, &bits, &flow);
1213 return uart_set_options(uport, co, baud, parity, bits, flow);
1214 }
1215
1216 static struct uart_driver zs_reg;
1217 static struct console zs_console = {
1218 .name = "ttyS",
1219 .write = zs_console_write,
1220 .device = uart_console_device,
1221 .setup = zs_console_setup,
1222 .flags = CON_PRINTBUFFER,
1223 .index = -1,
1224 .data = &zs_reg,
1225 };
1226
1227 /*
1228 * Register console.
1229 */
1230 static int __init zs_serial_console_init(void)
1231 {
1232 int ret;
1233
1234 ret = zs_probe_sccs();
1235 if (ret)
1236 return ret;
1237 register_console(&zs_console);
1238
1239 return 0;
1240 }
1241
1242 console_initcall(zs_serial_console_init);
1243
1244 #define SERIAL_ZS_CONSOLE &zs_console
1245 #else
1246 #define SERIAL_ZS_CONSOLE NULL
1247 #endif /* CONFIG_SERIAL_ZS_CONSOLE */
1248
1249 static struct uart_driver zs_reg = {
1250 .owner = THIS_MODULE,
1251 .driver_name = "serial",
1252 .dev_name = "ttyS",
1253 .major = TTY_MAJOR,
1254 .minor = 64,
1255 .nr = ZS_NUM_SCCS * ZS_NUM_CHAN,
1256 .cons = SERIAL_ZS_CONSOLE,
1257 };
1258
1259 /* zs_init inits the driver. */
1260 static int __init zs_init(void)
1261 {
1262 int i, ret;
1263
1264 pr_info("%s%s\n", zs_name, zs_version);
1265
1266 /* Find out how many Z85C30 SCCs we have. */
1267 ret = zs_probe_sccs();
1268 if (ret)
1269 return ret;
1270
1271 ret = uart_register_driver(&zs_reg);
1272 if (ret)
1273 return ret;
1274
1275 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) {
1276 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1277 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1278 struct uart_port *uport = &zport->port;
1279
1280 if (zport->scc)
1281 uart_add_one_port(&zs_reg, uport);
1282 }
1283
1284 return 0;
1285 }
1286
1287 static void __exit zs_exit(void)
1288 {
1289 int i;
1290
1291 for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) {
1292 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN];
1293 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN];
1294 struct uart_port *uport = &zport->port;
1295
1296 if (zport->scc)
1297 uart_remove_one_port(&zs_reg, uport);
1298 }
1299
1300 uart_unregister_driver(&zs_reg);
1301 }
1302
1303 module_init(zs_init);
1304 module_exit(zs_exit);
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