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path: root/drivers/serial/sunsab.c
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Diffstat (limited to 'drivers/serial/sunsab.c')
-rw-r--r--drivers/serial/sunsab.c109
1 files changed, 71 insertions, 38 deletions
diff --git a/drivers/serial/sunsab.c b/drivers/serial/sunsab.c
index 39b788d95e39..10e2990a40d4 100644
--- a/drivers/serial/sunsab.c
+++ b/drivers/serial/sunsab.c
@@ -61,6 +61,16 @@ struct uart_sunsab_port {
61 unsigned char pvr_dtr_bit; /* Which PVR bit is DTR */ 61 unsigned char pvr_dtr_bit; /* Which PVR bit is DTR */
62 unsigned char pvr_dsr_bit; /* Which PVR bit is DSR */ 62 unsigned char pvr_dsr_bit; /* Which PVR bit is DSR */
63 int type; /* SAB82532 version */ 63 int type; /* SAB82532 version */
64
65 /* Setting configuration bits while the transmitter is active
66 * can cause garbage characters to get emitted by the chip.
67 * Therefore, we cache such writes here and do the real register
68 * write the next time the transmitter becomes idle.
69 */
70 unsigned int cached_ebrg;
71 unsigned char cached_mode;
72 unsigned char cached_pvr;
73 unsigned char cached_dafo;
64}; 74};
65 75
66/* 76/*
@@ -236,6 +246,7 @@ receive_chars(struct uart_sunsab_port *up,
236} 246}
237 247
238static void sunsab_stop_tx(struct uart_port *, unsigned int); 248static void sunsab_stop_tx(struct uart_port *, unsigned int);
249static void sunsab_tx_idle(struct uart_sunsab_port *);
239 250
240static void transmit_chars(struct uart_sunsab_port *up, 251static void transmit_chars(struct uart_sunsab_port *up,
241 union sab82532_irq_status *stat) 252 union sab82532_irq_status *stat)
@@ -258,6 +269,7 @@ static void transmit_chars(struct uart_sunsab_port *up,
258 return; 269 return;
259 270
260 set_bit(SAB82532_XPR, &up->irqflags); 271 set_bit(SAB82532_XPR, &up->irqflags);
272 sunsab_tx_idle(up);
261 273
262 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { 274 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
263 up->interrupt_mask1 |= SAB82532_IMR1_XPR; 275 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
@@ -397,21 +409,21 @@ static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
397 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port; 409 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
398 410
399 if (mctrl & TIOCM_RTS) { 411 if (mctrl & TIOCM_RTS) {
400 writeb(readb(&up->regs->rw.mode) & ~SAB82532_MODE_FRTS, 412 up->cached_mode &= ~SAB82532_MODE_FRTS;
401 &up->regs->rw.mode); 413 up->cached_mode |= SAB82532_MODE_RTS;
402 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_RTS,
403 &up->regs->rw.mode);
404 } else { 414 } else {
405 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_FRTS, 415 up->cached_mode |= (SAB82532_MODE_FRTS |
406 &up->regs->rw.mode); 416 SAB82532_MODE_RTS);
407 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_RTS,
408 &up->regs->rw.mode);
409 } 417 }
410 if (mctrl & TIOCM_DTR) { 418 if (mctrl & TIOCM_DTR) {
411 writeb(readb(&up->regs->rw.pvr) & ~(up->pvr_dtr_bit), &up->regs->rw.pvr); 419 up->cached_pvr &= ~(up->pvr_dtr_bit);
412 } else { 420 } else {
413 writeb(readb(&up->regs->rw.pvr) | up->pvr_dtr_bit, &up->regs->rw.pvr); 421 up->cached_pvr |= up->pvr_dtr_bit;
414 } 422 }
423
424 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
425 if (test_bit(SAB82532_XPR, &up->irqflags))
426 sunsab_tx_idle(up);
415} 427}
416 428
417/* port->lock is not held. */ 429/* port->lock is not held. */
@@ -450,6 +462,25 @@ static void sunsab_stop_tx(struct uart_port *port, unsigned int tty_stop)
450} 462}
451 463
452/* port->lock held by caller. */ 464/* port->lock held by caller. */
465static void sunsab_tx_idle(struct uart_sunsab_port *up)
466{
467 if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
468 u8 tmp;
469
470 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
471 writeb(up->cached_mode, &up->regs->rw.mode);
472 writeb(up->cached_pvr, &up->regs->rw.pvr);
473 writeb(up->cached_dafo, &up->regs->w.dafo);
474
475 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
476 tmp = readb(&up->regs->rw.ccr2);
477 tmp &= ~0xc0;
478 tmp |= (up->cached_ebrg >> 2) & 0xc0;
479 writeb(tmp, &up->regs->rw.ccr2);
480 }
481}
482
483/* port->lock held by caller. */
453static void sunsab_start_tx(struct uart_port *port, unsigned int tty_start) 484static void sunsab_start_tx(struct uart_port *port, unsigned int tty_start)
454{ 485{
455 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port; 486 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
@@ -517,12 +548,16 @@ static void sunsab_break_ctl(struct uart_port *port, int break_state)
517 548
518 spin_lock_irqsave(&up->port.lock, flags); 549 spin_lock_irqsave(&up->port.lock, flags);
519 550
520 val = readb(&up->regs->rw.dafo); 551 val = up->cached_dafo;
521 if (break_state) 552 if (break_state)
522 val |= SAB82532_DAFO_XBRK; 553 val |= SAB82532_DAFO_XBRK;
523 else 554 else
524 val &= ~SAB82532_DAFO_XBRK; 555 val &= ~SAB82532_DAFO_XBRK;
525 writeb(val, &up->regs->rw.dafo); 556 up->cached_dafo = val;
557
558 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
559 if (test_bit(SAB82532_XPR, &up->irqflags))
560 sunsab_tx_idle(up);
526 561
527 spin_unlock_irqrestore(&up->port.lock, flags); 562 spin_unlock_irqrestore(&up->port.lock, flags);
528} 563}
@@ -566,8 +601,9 @@ static int sunsab_startup(struct uart_port *port)
566 SAB82532_CCR2_TOE, &up->regs->w.ccr2); 601 SAB82532_CCR2_TOE, &up->regs->w.ccr2);
567 writeb(0, &up->regs->w.ccr3); 602 writeb(0, &up->regs->w.ccr3);
568 writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4); 603 writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
569 writeb(SAB82532_MODE_RTS | SAB82532_MODE_FCTS | 604 up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
570 SAB82532_MODE_RAC, &up->regs->w.mode); 605 SAB82532_MODE_RAC);
606 writeb(up->cached_mode, &up->regs->w.mode);
571 writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc); 607 writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
572 608
573 tmp = readb(&up->regs->rw.ccr0); 609 tmp = readb(&up->regs->rw.ccr0);
@@ -598,7 +634,6 @@ static void sunsab_shutdown(struct uart_port *port)
598{ 634{
599 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port; 635 struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
600 unsigned long flags; 636 unsigned long flags;
601 unsigned char tmp;
602 637
603 spin_lock_irqsave(&up->port.lock, flags); 638 spin_lock_irqsave(&up->port.lock, flags);
604 639
@@ -609,14 +644,13 @@ static void sunsab_shutdown(struct uart_port *port)
609 writeb(up->interrupt_mask1, &up->regs->w.imr1); 644 writeb(up->interrupt_mask1, &up->regs->w.imr1);
610 645
611 /* Disable break condition */ 646 /* Disable break condition */
612 tmp = readb(&up->regs->rw.dafo); 647 up->cached_dafo = readb(&up->regs->rw.dafo);
613 tmp &= ~SAB82532_DAFO_XBRK; 648 up->cached_dafo &= ~SAB82532_DAFO_XBRK;
614 writeb(tmp, &up->regs->rw.dafo); 649 writeb(up->cached_dafo, &up->regs->rw.dafo);
615 650
616 /* Disable Receiver */ 651 /* Disable Receiver */
617 tmp = readb(&up->regs->rw.mode); 652 up->cached_mode &= ~SAB82532_MODE_RAC;
618 tmp &= ~SAB82532_MODE_RAC; 653 writeb(up->cached_mode, &up->regs->rw.mode);
619 writeb(tmp, &up->regs->rw.mode);
620 654
621 /* 655 /*
622 * XXX FIXME 656 * XXX FIXME
@@ -685,7 +719,6 @@ static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cfla
685 unsigned int iflag, unsigned int baud, 719 unsigned int iflag, unsigned int baud,
686 unsigned int quot) 720 unsigned int quot)
687{ 721{
688 unsigned int ebrg;
689 unsigned char dafo; 722 unsigned char dafo;
690 int bits, n, m; 723 int bits, n, m;
691 724
@@ -714,10 +747,11 @@ static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cfla
714 } else { 747 } else {
715 dafo |= SAB82532_DAFO_PAR_EVEN; 748 dafo |= SAB82532_DAFO_PAR_EVEN;
716 } 749 }
750 up->cached_dafo = dafo;
717 751
718 calc_ebrg(baud, &n, &m); 752 calc_ebrg(baud, &n, &m);
719 753
720 ebrg = n | (m << 6); 754 up->cached_ebrg = n | (m << 6);
721 755
722 up->tec_timeout = (10 * 1000000) / baud; 756 up->tec_timeout = (10 * 1000000) / baud;
723 up->cec_timeout = up->tec_timeout >> 2; 757 up->cec_timeout = up->tec_timeout >> 2;
@@ -770,16 +804,13 @@ static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cfla
770 uart_update_timeout(&up->port, cflag, 804 uart_update_timeout(&up->port, cflag,
771 (up->port.uartclk / (16 * quot))); 805 (up->port.uartclk / (16 * quot)));
772 806
773 /* Now bang the new settings into the chip. */ 807 /* Now schedule a register update when the chip's
774 sunsab_cec_wait(up); 808 * transmitter is idle.
775 sunsab_tec_wait(up); 809 */
776 writeb(dafo, &up->regs->w.dafo); 810 up->cached_mode |= SAB82532_MODE_RAC;
777 writeb(ebrg & 0xff, &up->regs->w.bgr); 811 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
778 writeb((readb(&up->regs->rw.ccr2) & ~0xc0) | ((ebrg >> 2) & 0xc0), 812 if (test_bit(SAB82532_XPR, &up->irqflags))
779 &up->regs->rw.ccr2); 813 sunsab_tx_idle(up);
780
781 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_RAC, &up->regs->rw.mode);
782
783} 814}
784 815
785/* port->lock is not held. */ 816/* port->lock is not held. */
@@ -1084,11 +1115,13 @@ static void __init sunsab_init_hw(void)
1084 up->pvr_dsr_bit = (1 << 3); 1115 up->pvr_dsr_bit = (1 << 3);
1085 up->pvr_dtr_bit = (1 << 2); 1116 up->pvr_dtr_bit = (1 << 2);
1086 } 1117 }
1087 writeb((1 << 1) | (1 << 2) | (1 << 4), &up->regs->w.pvr); 1118 up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1088 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_FRTS, 1119 writeb(up->cached_pvr, &up->regs->w.pvr);
1089 &up->regs->rw.mode); 1120 up->cached_mode = readb(&up->regs->rw.mode);
1090 writeb(readb(&up->regs->rw.mode) | SAB82532_MODE_RTS, 1121 up->cached_mode |= SAB82532_MODE_FRTS;
1091 &up->regs->rw.mode); 1122 writeb(up->cached_mode, &up->regs->rw.mode);
1123 up->cached_mode |= SAB82532_MODE_RTS;
1124 writeb(up->cached_mode, &up->regs->rw.mode);
1092 1125
1093 up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT; 1126 up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1094 up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT; 1127 up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;