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[Qemu-devel] [PATCH] upgrading emulated UART to 16550A
|
From: |
Stefano Stabellini |
|
Subject: |
[Qemu-devel] [PATCH] upgrading emulated UART to 16550A |
|
Date: |
Thu, 07 Aug 2008 18:35:52 +0100 |
|
User-agent: |
Thunderbird 2.0.0.14 (X11/20080505) |
This is an improved version of the UART 16550A emulation patch.
The changes compared to previous version are:
- no token bucket anymore;
- fixed a small bug handling IRQs; this was the problem that prevented
kgdb to work over the serial (thanks to Jason Wessel for the help
spotting and reproducing this bug).
Signed-off-by: Stefano Stabellini <address@hidden>
---
diff --git a/hw/serial.c b/hw/serial.c
index ffd6ac9..5aab00e 100644
--- a/hw/serial.c
+++ b/hw/serial.c
@@ -1,7 +1,7 @@
/*
- * QEMU 16450 UART emulation
+ * QEMU 16550A UART emulation
*
- * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
deal
@@ -21,6 +21,10 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
+
+#include <termios.h>
+#include <sys/ioctl.h>
+
#include "hw.h"
#include "qemu-char.h"
#include "isa.h"
@@ -43,6 +47,10 @@
#define UART_IIR_THRI 0x02 /* Transmitter holding register empty */
#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
+#define UART_IIR_CTI 0x0C /* Character Timeout Indication */
+
+#define UART_IIR_FENF 0x80 /* Fifo enabled, but not functionning */
+#define UART_IIR_FE 0xC0 /* Fifo enabled */
/*
* These are the definitions for the Modem Control Register
@@ -73,17 +81,39 @@
#define UART_LSR_PE 0x04 /* Parity error indicator */
#define UART_LSR_OE 0x02 /* Overrun error indicator */
#define UART_LSR_DR 0x01 /* Receiver data ready */
-
-/*
- * Delay TX IRQ after sending as much characters as the given interval would
- * contain on real hardware. This avoids overloading the guest if it processes
- * its output buffer in a loop inside the TX IRQ handler.
- */
-#define THROTTLE_TX_INTERVAL 10 /* ms */
+#define UART_LSR_INT_ANY 0x1E /* Any of the lsr-interrupt-triggering status
bits */
+
+/* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs
the byte-count for each ITL is higher. */
+
+#define UART_FCR_ITL_1 0x00 /* 1 byte ITL */
+#define UART_FCR_ITL_2 0x40 /* 4 bytes ITL */
+#define UART_FCR_ITL_3 0x80 /* 8 bytes ITL */
+#define UART_FCR_ITL_4 0xC0 /* 14 bytes ITL */
+
+#define UART_FCR_DMS 0x08 /* DMA Mode Select */
+#define UART_FCR_XFR 0x04 /* XMIT Fifo Reset */
+#define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */
+#define UART_FCR_FE 0x01 /* FIFO Enable */
+
+#define UART_FIFO_LENGTH 16 /* 16550A Fifo Length */
+
+#define XMIT_FIFO 0
+#define RECV_FIFO 1
+#define MAX_XMIT_RETRY 4
+
+struct SerialFIFO {
+ uint8_t data[UART_FIFO_LENGTH];
+ uint8_t count;
+ uint8_t itl; /* Interrupt Trigger Level */
+ uint8_t tail;
+ uint8_t head;
+} typedef SerialFIFO;
struct SerialState {
uint16_t divider;
uint8_t rbr; /* receive register */
+ uint8_t thr; /* transmit holding register */
+ uint8_t tsr; /* transmit shift register */
uint8_t ier;
uint8_t iir; /* read only */
uint8_t lcr;
@@ -91,6 +121,7 @@ struct SerialState {
uint8_t lsr; /* read only */
uint8_t msr; /* read only */
uint8_t scr;
+ uint8_t fcr;
/* NOTE: this hidden state is necessary for tx irq generation as
it can be reset while reading iir */
int thr_ipending;
@@ -100,55 +131,105 @@ struct SerialState {
target_phys_addr_t base;
int it_shift;
int baudbase;
- QEMUTimer *tx_timer;
- int tx_burst;
+ int tsr_retry;
+
+ uint64_t last_xmit_ts; /* Time when the last byte was
successfully sent out of the tsr */
+ SerialFIFO recv_fifo;
+ SerialFIFO xmit_fifo;
+
+ struct QEMUTimer *fifo_timeout_timer;
+ int timeout_ipending; /* timeout interrupt pending state
*/
+ struct QEMUTimer *transmit_timer;
+
+
+ uint64_t char_transmit_time; /* time to transmit a char in
ticks*/
+ int poll_msl;
+
+ struct QEMUTimer *modem_status_poll;
};
+static void serial_receive1(void *opaque, const uint8_t *buf, int size);
+
+static void fifo_clear(SerialState *s, int fifo) {
+ SerialFIFO *f = ( fifo ) ? &s->recv_fifo : &s->xmit_fifo;
+ memset(f->data, 0, UART_FIFO_LENGTH);
+ f->count = 0;
+ f->head = 0;
+ f->tail = 0;
+}
+
+static int fifo_put(SerialState *s, int fifo, uint8_t chr) {
+ SerialFIFO *f = ( fifo ) ? &s->recv_fifo : &s->xmit_fifo;
+
+ f->data[f->head++] = chr;
+
+ if (f->head == UART_FIFO_LENGTH)
+ f->head = 0;
+ f->count++;
+
+ return 1;
+}
+
+uint8_t fifo_get(SerialState *s, int fifo) {
+ SerialFIFO *f = ( fifo ) ? &s->recv_fifo : &s->xmit_fifo;
+ uint8_t c;
+
+ if( f->count == 0 )
+ return 0;
+
+ c = f->data[f->tail++];
+ if (f->tail == UART_FIFO_LENGTH)
+ f->tail = 0;
+ f->count--;
+
+ return c;
+}
+
static void serial_receive_byte(SerialState *s, int ch);
static void serial_update_irq(SerialState *s)
{
- if ((s->lsr & UART_LSR_DR) && (s->ier & UART_IER_RDI)) {
- s->iir = UART_IIR_RDI;
- } else if (s->thr_ipending && (s->ier & UART_IER_THRI)) {
- s->iir = UART_IIR_THRI;
- } else {
- s->iir = UART_IIR_NO_INT;
- }
- if (s->iir != UART_IIR_NO_INT) {
- qemu_irq_raise(s->irq);
- } else {
+ uint8_t tmp_iir = UART_IIR_NO_INT;
+
+ if (!s->ier) {
qemu_irq_lower(s->irq);
+ return;
}
-}
-
-static void serial_tx_done(void *opaque)
-{
- SerialState *s = opaque;
- if (s->tx_burst < 0) {
- uint16_t divider;
+ if ( ( s->ier & UART_IER_RLSI ) && (s->lsr & UART_LSR_INT_ANY ) ) {
+ tmp_iir = UART_IIR_RLSI;
+ } else if ( s->timeout_ipending ) {
+ tmp_iir = UART_IIR_CTI;
+ } else if ( ( s->ier & UART_IER_RDI ) && (s->lsr & UART_LSR_DR ) ) {
+ if ( !(s->fcr & UART_FCR_FE) ) {
+ tmp_iir = UART_IIR_RDI;
+ } else if ( s->recv_fifo.count >= s->recv_fifo.itl ) {
+ tmp_iir = UART_IIR_RDI;
+ }
+ } else if ( (s->ier & UART_IER_THRI) && s->thr_ipending ) {
+ tmp_iir = UART_IIR_THRI;
+ } else if ( (s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA) ) {
+ tmp_iir = UART_IIR_MSI;
+ }
- if (s->divider)
- divider = s->divider;
- else
- divider = 1;
+ s->iir = tmp_iir | ( s->iir & 0xF0 );
- /* We assume 10 bits/char, OK for this purpose. */
- s->tx_burst = THROTTLE_TX_INTERVAL * 1000 /
- (1000000 * 10 / (s->baudbase / divider));
+ if ( tmp_iir != UART_IIR_NO_INT ) {
+ qemu_irq_raise(s->irq);
+ } else {
+ qemu_irq_lower(s->irq);
}
- s->thr_ipending = 1;
- s->lsr |= UART_LSR_THRE;
- s->lsr |= UART_LSR_TEMT;
- serial_update_irq(s);
}
static void serial_update_parameters(SerialState *s)
{
- int speed, parity, data_bits, stop_bits;
+ int speed, parity, data_bits, stop_bits, frame_size;
QEMUSerialSetParams ssp;
+ if (s->divider == 0)
+ return;
+
+ frame_size = 1;
if (s->lcr & 0x08) {
if (s->lcr & 0x10)
parity = 'E';
@@ -156,19 +237,21 @@ static void serial_update_parameters(SerialState *s)
parity = 'O';
} else {
parity = 'N';
+ frame_size = 0;
}
if (s->lcr & 0x04)
stop_bits = 2;
else
stop_bits = 1;
+
data_bits = (s->lcr & 0x03) + 5;
- if (s->divider == 0)
- return;
+ frame_size += data_bits + stop_bits;
speed = s->baudbase / s->divider;
ssp.speed = speed;
ssp.parity = parity;
ssp.data_bits = data_bits;
ssp.stop_bits = stop_bits;
+ s->char_transmit_time = ( ticks_per_sec / speed ) * frame_size;
qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
#if 0
printf("speed=%d parity=%c data=%d stop=%d\n",
@@ -176,6 +259,88 @@ static void serial_update_parameters(SerialState *s)
#endif
}
+static void serial_update_msl( SerialState *s )
+{
+ uint8_t omsr;
+ int flags;
+
+ qemu_del_timer(s->modem_status_poll);
+
+ if ( qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags) == -ENOTSUP
) {
+ s->poll_msl = -1;
+ return;
+ }
+
+ omsr = s->msr;
+
+ s->msr = ( flags & TIOCM_CTS ) ? s->msr | UART_MSR_CTS : s->msr &
~UART_MSR_CTS;
+ s->msr = ( flags & TIOCM_DSR ) ? s->msr | UART_MSR_DSR : s->msr &
~UART_MSR_DSR;
+ s->msr = ( flags & TIOCM_CAR ) ? s->msr | UART_MSR_DCD : s->msr &
~UART_MSR_DCD;
+ s->msr = ( flags & TIOCM_RI ) ? s->msr | UART_MSR_RI : s->msr &
~UART_MSR_RI;
+
+ if ( s->msr != omsr ) {
+ /* Set delta bits */
+ s->msr = s->msr | ( ( s->msr >> 4 ) ^ ( omsr >> 4 ) );
+ /* UART_MSR_TERI only if change was from 1 -> 0 */
+ if ( ( s->msr & UART_MSR_TERI ) && !( omsr & UART_MSR_RI ) )
+ s->msr &= ~UART_MSR_TERI;
+ serial_update_irq(s);
+ }
+
+ /* The real 16550A apparently has a 250ns response latency to line status
changes.
+ We'll be lazy and poll only every 10ms, and only poll it at all if MSI
interrupts are turned on */
+
+ if ( s->poll_msl )
+ qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) +
ticks_per_sec / 100);
+}
+
+static void serial_xmit(void *opaque) {
+ SerialState *s = opaque;
+ uint64_t new_xmit_ts = qemu_get_clock(vm_clock);
+
+ if ( s->tsr_retry <= 0 ) {
+ if (s->fcr & UART_FCR_FE) {
+ s->tsr = fifo_get(s,XMIT_FIFO);
+ if ( !s->xmit_fifo.count )
+ s->lsr |= UART_LSR_THRE;
+ } else {
+ s->tsr = s->thr;
+ s->lsr |= UART_LSR_THRE;
+ }
+ }
+
+ if ( (s->mcr & UART_MCR_LOOP
+ /* in loopback mode, say that we just received a char */
+ ? (serial_receive1(s, &s->tsr, 1), 1)
+ : qemu_chr_write(s->chr, &s->tsr, 1))
+ != 1 ) {
+ if ( ( s->tsr_retry > 0 ) && ( s->tsr_retry <= MAX_XMIT_RETRY ) ) {
+ s->tsr_retry++;
+ qemu_mod_timer(s->transmit_timer, new_xmit_ts +
s->char_transmit_time );
+ return;
+ } else if ( s->poll_msl < 0 ) {
+ /* If we exceed MAX_XMIT_RETRY and the backend is not a real
serial port, then
+ drop any further failed writes instantly, until we get one that
goes through.
+ This is to prevent guests that log to unconnected pipes or pty's
from stalling. */
+ s->tsr_retry = -1;
+ }
+ }
+ else {
+ s->tsr_retry = 0;
+ }
+
+ s->last_xmit_ts = qemu_get_clock(vm_clock);
+ if ( !(s->lsr & UART_LSR_THRE) )
+ qemu_mod_timer(s->transmit_timer, s->last_xmit_ts +
s->char_transmit_time );
+
+ if ( s->lsr & UART_LSR_THRE ) {
+ s->lsr |= UART_LSR_TEMT;
+ s->thr_ipending = 1;
+ serial_update_irq(s);
+ }
+}
+
+
static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
SerialState *s = opaque;
@@ -192,25 +357,19 @@ static void serial_ioport_write(void *opaque, uint32_t
addr, uint32_t val)
s->divider = (s->divider & 0xff00) | val;
serial_update_parameters(s);
} else {
+ s->thr = (uint8_t) val;
+ if(s->fcr & UART_FCR_FE) {
+ fifo_put(s, XMIT_FIFO, s->thr);
s->thr_ipending = 0;
+ s->lsr &= ~UART_LSR_TEMT;
s->lsr &= ~UART_LSR_THRE;
serial_update_irq(s);
- ch = val;
- if (!(s->mcr & UART_MCR_LOOP)) {
- /* when not in loopback mode, send the char */
- qemu_chr_write(s->chr, &ch, 1);
} else {
- /* in loopback mode, say that we just received a char */
- serial_receive_byte(s, ch);
- }
- if (s->tx_burst > 0) {
- s->tx_burst--;
- serial_tx_done(s);
- } else if (s->tx_burst == 0) {
- s->tx_burst--;
- qemu_mod_timer(s->tx_timer, qemu_get_clock(vm_clock) +
- ticks_per_sec * THROTTLE_TX_INTERVAL / 1000);
+ s->thr_ipending = 0;
+ s->lsr &= ~UART_LSR_THRE;
+ serial_update_irq(s);
}
+ serial_xmit(s);
}
break;
case 1:
@@ -219,13 +378,68 @@ static void serial_ioport_write(void *opaque, uint32_t
addr, uint32_t val)
serial_update_parameters(s);
} else {
s->ier = val & 0x0f;
+ /* If the backend device is a real serial port, turn polling of
the modem
+ status lines on physical port on or off depending on
UART_IER_MSI state */
+ if ( s->poll_msl >= 0 ) {
+ if ( s->ier & UART_IER_MSI ) {
+ s->poll_msl = 1;
+ serial_update_msl(s);
+ } else {
+ qemu_del_timer(s->modem_status_poll);
+ s->poll_msl = 0;
+ }
+ }
if (s->lsr & UART_LSR_THRE) {
s->thr_ipending = 1;
+ serial_update_irq(s);
}
- serial_update_irq(s);
}
break;
case 2:
+ val = val & 0xFF;
+
+ if ( s->fcr == val)
+ break;
+
+ /* Did the enable/disable flag change? If so, make sure FIFOs get
flushed */
+ if ( (val ^ s->fcr) & UART_FCR_FE )
+ val |= UART_FCR_XFR | UART_FCR_RFR;
+
+ /* FIFO clear */
+
+ if ( val & UART_FCR_RFR ) {
+ qemu_del_timer(s->fifo_timeout_timer);
+ s->timeout_ipending=0;
+ fifo_clear(s,RECV_FIFO);
+ }
+
+ if ( val & UART_FCR_XFR ) {
+ fifo_clear(s,XMIT_FIFO);
+ }
+
+ if ( val & UART_FCR_FE ) {
+ s->iir |= UART_IIR_FE;
+ /* Set RECV_FIFO trigger Level */
+ switch ( val & 0xC0 ) {
+ case UART_FCR_ITL_1:
+ s->recv_fifo.itl = 1;
+ break;
+ case UART_FCR_ITL_2:
+ s->recv_fifo.itl = 4;
+ break;
+ case UART_FCR_ITL_3:
+ s->recv_fifo.itl = 8;
+ break;
+ case UART_FCR_ITL_4:
+ s->recv_fifo.itl = 14;
+ break;
+ }
+ } else
+ s->iir &= ~UART_IIR_FE;
+
+ /* Set fcr - or at least the bits in it that are supposed to "stick" */
+ s->fcr = val & 0xC9;
+ serial_update_irq(s);
break;
case 3:
{
@@ -241,7 +455,30 @@ static void serial_ioport_write(void *opaque, uint32_t
addr, uint32_t val)
}
break;
case 4:
- s->mcr = val & 0x1f;
+ {
+ int flags;
+ int old_mcr = s->mcr;
+ s->mcr = val & 0x1f;
+ if ( val & UART_MCR_LOOP )
+ break;
+
+ if ( s->poll_msl >= 0 && old_mcr != s->mcr ) {
+
+ qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags);
+
+ flags &= ~( TIOCM_RTS | TIOCM_DTR );
+
+ if ( val & UART_MCR_RTS )
+ flags |= TIOCM_RTS;
+ if ( val & UART_MCR_DTR )
+ flags |= TIOCM_DTR;
+
+ qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_SET_TIOCM, &flags);
+ /* Update the modem status after a one-character-send
wait-time, since there may be a response
+ from the device/computer at the other end of the serial
line */
+ qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock)
+ s->char_transmit_time );
+ }
+ }
break;
case 5:
break;
@@ -265,8 +502,17 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t
addr)
if (s->lcr & UART_LCR_DLAB) {
ret = s->divider & 0xff;
} else {
- ret = s->rbr;
- s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ if(s->fcr & UART_FCR_FE) {
+ ret = fifo_get(s,RECV_FIFO);
+ if ( s->recv_fifo.count == 0 )
+ s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ else
+ qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock
(vm_clock) + s->char_transmit_time * 4 );
+ s->timeout_ipending = 0;
+ } else {
+ ret = s->rbr;
+ s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ }
serial_update_irq(s);
if (!(s->mcr & UART_MCR_LOOP)) {
/* in loopback mode, don't receive any data */
@@ -283,8 +529,6 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t
addr)
break;
case 2:
ret = s->iir;
- /* reset THR pending bit */
- if ((ret & 0x7) == UART_IIR_THRI)
s->thr_ipending = 0;
serial_update_irq(s);
break;
@@ -296,6 +540,11 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t
addr)
break;
case 5:
ret = s->lsr;
+ /* Clear break interrupt */
+ if ( s->lsr & UART_LSR_BI ) {
+ s->lsr &= ~UART_LSR_BI;
+ serial_update_irq(s);
+ }
break;
case 6:
if (s->mcr & UART_MCR_LOOP) {
@@ -305,7 +554,14 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t
addr)
ret |= (s->mcr & 0x02) << 3;
ret |= (s->mcr & 0x01) << 5;
} else {
+ if ( s->poll_msl >= 0 )
+ serial_update_msl(s);
ret = s->msr;
+ /* Clear delta bits & msr int after read, if they were set */
+ if ( s->msr & UART_MSR_ANY_DELTA ) {
+ s->msr &= 0xF0;
+ serial_update_irq(s);
+ }
}
break;
case 7:
@@ -320,14 +576,17 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t
addr)
static int serial_can_receive(SerialState *s)
{
+ if(s->fcr & UART_FCR_FE) {
+ if(s->recv_fifo.count < UART_FIFO_LENGTH)
+ /* Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1 if
above. If UART_FIFO_LENGTH - fifo.count is
+ advertised the effect will be to almost always fill the fifo
completely before the guest has a chance to respond,
+ effectively overriding the ITL that the guest has set. */
+ return ( s->recv_fifo.count <= s->recv_fifo.itl ) ?
s->recv_fifo.itl - s->recv_fifo.count : 1;
+ else
+ return 0;
+ } else {
return !(s->lsr & UART_LSR_DR);
-}
-
-static void serial_receive_byte(SerialState *s, int ch)
-{
- s->rbr = ch;
- s->lsr |= UART_LSR_DR;
- serial_update_irq(s);
+ }
}
static void serial_receive_break(SerialState *s)
@@ -337,6 +596,15 @@ static void serial_receive_break(SerialState *s)
serial_update_irq(s);
}
+/* There's data in recv_fifo and s->rbr has not been read for 4 char transmit
times */
+static void fifo_timeout_int (void *opaque) {
+ SerialState *s = opaque;
+ if ( s->recv_fifo.count ) {
+ s->timeout_ipending = 1;
+ serial_update_irq(s);
+ }
+}
+
static int serial_can_receive1(void *opaque)
{
SerialState *s = opaque;
@@ -346,12 +614,27 @@ static int serial_can_receive1(void *opaque)
static void serial_receive1(void *opaque, const uint8_t *buf, int size)
{
SerialState *s = opaque;
- serial_receive_byte(s, buf[0]);
+ if(s->fcr & UART_FCR_FE) {
+ int i;
+ for (i = 0; i < size; i++) {
+ fifo_put(s, RECV_FIFO, buf[i]);
+ }
+ s->lsr |= UART_LSR_DR;
+ /* call the timeout receive callback in 4 char transmit time */
+ qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) +
s->char_transmit_time * 4);
+ } else {
+ s->rbr = buf[0];
+ s->lsr |= UART_LSR_DR;
+ }
+ serial_update_irq(s);
}
static void serial_event(void *opaque, int event)
{
SerialState *s = opaque;
+#ifdef DEBUG_SERIAL
+ printf("serial: event %x\n", event);
+#endif
if (event == CHR_EVENT_BREAK)
serial_receive_break(s);
}
@@ -369,11 +652,13 @@ static void serial_save(QEMUFile *f, void *opaque)
qemu_put_8s(f,&s->lsr);
qemu_put_8s(f,&s->msr);
qemu_put_8s(f,&s->scr);
+ qemu_put_8s(f,&s->fcr);
}
static int serial_load(QEMUFile *f, void *opaque, int version_id)
{
SerialState *s = opaque;
+ uint8_t fcr = 0;
if(version_id > 2)
return -EINVAL;
@@ -391,6 +676,11 @@ static int serial_load(QEMUFile *f, void *opaque, int
version_id)
qemu_get_8s(f,&s->msr);
qemu_get_8s(f,&s->scr);
+ if (version_id >= 2)
+ qemu_get_8s(f,&fcr);
+
+ /* Initialize fcr via setter to perform essential side-effects */
+ serial_ioport_write(s, 0x02, fcr);
return 0;
}
@@ -398,21 +688,47 @@ static void serial_reset(void *opaque)
{
SerialState *s = opaque;
- s->divider = 0;
s->rbr = 0;
s->ier = 0;
s->iir = UART_IIR_NO_INT;
s->lcr = 0;
- s->mcr = 0;
s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
+ /* Default to 9600 baud, no parity, one stop bit */
+ s->divider = 0x0C;
+ s->mcr = UART_MCR_OUT2;
s->scr = 0;
+ s->tsr_retry = 0;
+ s->char_transmit_time = ( ticks_per_sec / 9600 ) * 9;
+ s->poll_msl = 0;
+
+ fifo_clear(s,RECV_FIFO);
+ fifo_clear(s,XMIT_FIFO);
+
+ s->last_xmit_ts = qemu_get_clock(vm_clock);
s->thr_ipending = 0;
s->last_break_enable = 0;
qemu_irq_lower(s->irq);
}
+static void serial_init_core(SerialState *s, qemu_irq irq, int baudbase,
+ CharDriverState *chr)
+{
+ s->irq = irq;
+ s->baudbase = baudbase;
+ s->chr = chr;
+
+ s->modem_status_poll = qemu_new_timer(vm_clock, ( QEMUTimerCB *)
serial_update_msl, s);
+
+ s->fifo_timeout_timer = qemu_new_timer(vm_clock, ( QEMUTimerCB *)
fifo_timeout_int, s);
+ s->transmit_timer = qemu_new_timer(vm_clock, ( QEMUTimerCB *) serial_xmit,
s);
+
+ qemu_register_reset(serial_reset, s);
+ serial_reset(s);
+
+}
+
/* If fd is zero, it means that the serial device uses the console */
SerialState *serial_init(int base, qemu_irq irq, int baudbase,
CharDriverState *chr)
@@ -422,21 +738,13 @@ SerialState *serial_init(int base, qemu_irq irq, int
baudbase,
s = qemu_mallocz(sizeof(SerialState));
if (!s)
return NULL;
- s->irq = irq;
- s->baudbase = baudbase;
-
- s->tx_timer = qemu_new_timer(vm_clock, serial_tx_done, s);
- if (!s->tx_timer)
- return NULL;
- qemu_register_reset(serial_reset, s);
- serial_reset(s);
+ serial_init_core(s, irq, baudbase, chr);
register_savevm("serial", base, 2, serial_save, serial_load, s);
register_ioport_write(base, 8, 1, serial_ioport_write, s);
register_ioport_read(base, 8, 1, serial_ioport_read, s);
- s->chr = chr;
qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
serial_event, s);
return s;
@@ -524,18 +832,11 @@ SerialState *serial_mm_init (target_phys_addr_t base, int
it_shift,
s = qemu_mallocz(sizeof(SerialState));
if (!s)
return NULL;
- s->irq = irq;
+
s->base = base;
s->it_shift = it_shift;
- s->baudbase= baudbase;
-
- s->tx_timer = qemu_new_timer(vm_clock, serial_tx_done, s);
- if (!s->tx_timer)
- return NULL;
-
- qemu_register_reset(serial_reset, s);
- serial_reset(s);
+ serial_init_core(s, irq, baudbase, chr);
register_savevm("serial", base, 2, serial_save, serial_load, s);
if (ioregister) {
@@ -543,8 +844,8 @@ SerialState *serial_mm_init (target_phys_addr_t base, int
it_shift,
serial_mm_write, s);
cpu_register_physical_memory(base, 8 << it_shift, s_io_memory);
}
- s->chr = chr;
qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
serial_event, s);
+ serial_update_msl(s);
return s;
}
diff --git a/qemu-char.h b/qemu-char.h
index 29de03d..41936bc 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -28,6 +28,9 @@ typedef struct {
#define CHR_IOCTL_PP_EPP_WRITE_ADDR 10
#define CHR_IOCTL_PP_EPP_WRITE 11
+#define CHR_IOCTL_SERIAL_SET_TIOCM 12
+#define CHR_IOCTL_SERIAL_GET_TIOCM 13
+
typedef void IOEventHandler(void *opaque, int event);
struct CharDriverState {
diff --git a/vl.c b/vl.c
index 03cd386..e9177b1 100644
--- a/vl.c
+++ b/vl.c
@@ -2721,6 +2721,17 @@ static int tty_serial_ioctl(CharDriverState *chr, int
cmd, void *arg)
tcsendbreak(s->fd_in, 1);
}
break;
+ case CHR_IOCTL_SERIAL_GET_TIOCM:
+ {
+ ioctl(s->fd_in, TIOCMGET, arg);
+ }
+ break;
+ case CHR_IOCTL_SERIAL_SET_TIOCM:
+ {
+ ioctl(s->fd_in, TIOCMSET, arg);
+ }
+ break;
+
default:
return -ENOTSUP;
}
[Qemu-devel] [PATCH] upgrading emulated UART to 16550A, Stefano Stabellini, 2008/08/08
[Qemu-devel] [PATCH] upgrading emulated UART to 16550A, Stefano Stabellini, 2008/08/08