8da3ff1809
Signed-off-by: Paul Brook <paul@codesourcery.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5849 c046a42c-6fe2-441c-8c8c-71466251a162
845 lines
25 KiB
C
845 lines
25 KiB
C
/*
|
|
* QEMU 16550A UART emulation
|
|
*
|
|
* Copyright (c) 2003-2004 Fabrice Bellard
|
|
* Copyright (c) 2008 Citrix Systems, Inc.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
#include "hw.h"
|
|
#include "qemu-char.h"
|
|
#include "isa.h"
|
|
#include "pc.h"
|
|
#include "qemu-timer.h"
|
|
|
|
//#define DEBUG_SERIAL
|
|
|
|
#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
|
|
|
|
#define UART_IER_MSI 0x08 /* Enable Modem status interrupt */
|
|
#define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */
|
|
#define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */
|
|
#define UART_IER_RDI 0x01 /* Enable receiver data interrupt */
|
|
|
|
#define UART_IIR_NO_INT 0x01 /* No interrupts pending */
|
|
#define UART_IIR_ID 0x06 /* Mask for the interrupt ID */
|
|
|
|
#define UART_IIR_MSI 0x00 /* Modem status interrupt */
|
|
#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
|
|
*/
|
|
#define UART_MCR_LOOP 0x10 /* Enable loopback test mode */
|
|
#define UART_MCR_OUT2 0x08 /* Out2 complement */
|
|
#define UART_MCR_OUT1 0x04 /* Out1 complement */
|
|
#define UART_MCR_RTS 0x02 /* RTS complement */
|
|
#define UART_MCR_DTR 0x01 /* DTR complement */
|
|
|
|
/*
|
|
* These are the definitions for the Modem Status Register
|
|
*/
|
|
#define UART_MSR_DCD 0x80 /* Data Carrier Detect */
|
|
#define UART_MSR_RI 0x40 /* Ring Indicator */
|
|
#define UART_MSR_DSR 0x20 /* Data Set Ready */
|
|
#define UART_MSR_CTS 0x10 /* Clear to Send */
|
|
#define UART_MSR_DDCD 0x08 /* Delta DCD */
|
|
#define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */
|
|
#define UART_MSR_DDSR 0x02 /* Delta DSR */
|
|
#define UART_MSR_DCTS 0x01 /* Delta CTS */
|
|
#define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */
|
|
|
|
#define UART_LSR_TEMT 0x40 /* Transmitter empty */
|
|
#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
|
|
#define UART_LSR_BI 0x10 /* Break interrupt indicator */
|
|
#define UART_LSR_FE 0x08 /* Frame error indicator */
|
|
#define UART_LSR_PE 0x04 /* Parity error indicator */
|
|
#define UART_LSR_OE 0x02 /* Overrun error indicator */
|
|
#define UART_LSR_DR 0x01 /* Receiver data ready */
|
|
#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;
|
|
uint8_t mcr;
|
|
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;
|
|
qemu_irq irq;
|
|
CharDriverState *chr;
|
|
int last_break_enable;
|
|
int it_shift;
|
|
int baudbase;
|
|
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;
|
|
}
|
|
|
|
static 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_update_irq(SerialState *s)
|
|
{
|
|
uint8_t tmp_iir = UART_IIR_NO_INT;
|
|
|
|
if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
|
|
tmp_iir = UART_IIR_RLSI;
|
|
} else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) {
|
|
/* Note that(s->ier & UART_IER_RDI) can mask this interrupt,
|
|
* this is not in the specification but is observed on existing
|
|
* hardware. */
|
|
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;
|
|
}
|
|
|
|
s->iir = tmp_iir | (s->iir & 0xF0);
|
|
|
|
if (tmp_iir != UART_IIR_NO_INT) {
|
|
qemu_irq_raise(s->irq);
|
|
} else {
|
|
qemu_irq_lower(s->irq);
|
|
}
|
|
}
|
|
|
|
static void serial_update_parameters(SerialState *s)
|
|
{
|
|
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';
|
|
else
|
|
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;
|
|
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",
|
|
speed, parity, data_bits, stop_bits);
|
|
#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 & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS;
|
|
s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR;
|
|
s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD;
|
|
s->msr = (flags & CHR_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);
|
|
} else if (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;
|
|
|
|
addr &= 7;
|
|
#ifdef DEBUG_SERIAL
|
|
printf("serial: write addr=0x%02x val=0x%02x\n", addr, val);
|
|
#endif
|
|
switch(addr) {
|
|
default:
|
|
case 0:
|
|
if (s->lcr & UART_LCR_DLAB) {
|
|
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);
|
|
} else {
|
|
s->thr_ipending = 0;
|
|
s->lsr &= ~UART_LSR_THRE;
|
|
serial_update_irq(s);
|
|
}
|
|
serial_xmit(s);
|
|
}
|
|
break;
|
|
case 1:
|
|
if (s->lcr & UART_LCR_DLAB) {
|
|
s->divider = (s->divider & 0x00ff) | (val << 8);
|
|
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);
|
|
}
|
|
}
|
|
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:
|
|
{
|
|
int break_enable;
|
|
s->lcr = val;
|
|
serial_update_parameters(s);
|
|
break_enable = (val >> 6) & 1;
|
|
if (break_enable != s->last_break_enable) {
|
|
s->last_break_enable = break_enable;
|
|
qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
|
|
&break_enable);
|
|
}
|
|
}
|
|
break;
|
|
case 4:
|
|
{
|
|
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 &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR);
|
|
|
|
if (val & UART_MCR_RTS)
|
|
flags |= CHR_TIOCM_RTS;
|
|
if (val & UART_MCR_DTR)
|
|
flags |= CHR_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;
|
|
case 6:
|
|
break;
|
|
case 7:
|
|
s->scr = val;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static uint32_t serial_ioport_read(void *opaque, uint32_t addr)
|
|
{
|
|
SerialState *s = opaque;
|
|
uint32_t ret;
|
|
|
|
addr &= 7;
|
|
switch(addr) {
|
|
default:
|
|
case 0:
|
|
if (s->lcr & UART_LCR_DLAB) {
|
|
ret = s->divider & 0xff;
|
|
} else {
|
|
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 */
|
|
qemu_chr_accept_input(s->chr);
|
|
}
|
|
}
|
|
break;
|
|
case 1:
|
|
if (s->lcr & UART_LCR_DLAB) {
|
|
ret = (s->divider >> 8) & 0xff;
|
|
} else {
|
|
ret = s->ier;
|
|
}
|
|
break;
|
|
case 2:
|
|
ret = s->iir;
|
|
s->thr_ipending = 0;
|
|
serial_update_irq(s);
|
|
break;
|
|
case 3:
|
|
ret = s->lcr;
|
|
break;
|
|
case 4:
|
|
ret = s->mcr;
|
|
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) {
|
|
/* in loopback, the modem output pins are connected to the
|
|
inputs */
|
|
ret = (s->mcr & 0x0c) << 4;
|
|
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:
|
|
ret = s->scr;
|
|
break;
|
|
}
|
|
#ifdef DEBUG_SERIAL
|
|
printf("serial: read addr=0x%02x val=0x%02x\n", addr, ret);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
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_break(SerialState *s)
|
|
{
|
|
s->rbr = 0;
|
|
s->lsr |= UART_LSR_BI | UART_LSR_DR;
|
|
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;
|
|
return serial_can_receive(s);
|
|
}
|
|
|
|
static void serial_receive1(void *opaque, const uint8_t *buf, int size)
|
|
{
|
|
SerialState *s = opaque;
|
|
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);
|
|
}
|
|
|
|
static void serial_save(QEMUFile *f, void *opaque)
|
|
{
|
|
SerialState *s = opaque;
|
|
|
|
qemu_put_be16s(f,&s->divider);
|
|
qemu_put_8s(f,&s->rbr);
|
|
qemu_put_8s(f,&s->ier);
|
|
qemu_put_8s(f,&s->iir);
|
|
qemu_put_8s(f,&s->lcr);
|
|
qemu_put_8s(f,&s->mcr);
|
|
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 > 3)
|
|
return -EINVAL;
|
|
|
|
if (version_id >= 2)
|
|
qemu_get_be16s(f, &s->divider);
|
|
else
|
|
s->divider = qemu_get_byte(f);
|
|
qemu_get_8s(f,&s->rbr);
|
|
qemu_get_8s(f,&s->ier);
|
|
qemu_get_8s(f,&s->iir);
|
|
qemu_get_8s(f,&s->lcr);
|
|
qemu_get_8s(f,&s->mcr);
|
|
qemu_get_8s(f,&s->lsr);
|
|
qemu_get_8s(f,&s->msr);
|
|
qemu_get_8s(f,&s->scr);
|
|
|
|
if (version_id >= 3)
|
|
qemu_get_8s(f,&fcr);
|
|
|
|
/* Initialize fcr via setter to perform essential side-effects */
|
|
serial_ioport_write(s, 0x02, fcr);
|
|
return 0;
|
|
}
|
|
|
|
static void serial_reset(void *opaque)
|
|
{
|
|
SerialState *s = opaque;
|
|
|
|
s->rbr = 0;
|
|
s->ier = 0;
|
|
s->iir = UART_IIR_NO_INT;
|
|
s->lcr = 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)
|
|
{
|
|
SerialState *s;
|
|
|
|
s = qemu_mallocz(sizeof(SerialState));
|
|
if (!s)
|
|
return NULL;
|
|
|
|
serial_init_core(s, irq, baudbase, chr);
|
|
|
|
register_savevm("serial", base, 3, 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);
|
|
qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
|
|
serial_event, s);
|
|
return s;
|
|
}
|
|
|
|
/* Memory mapped interface */
|
|
uint32_t serial_mm_readb (void *opaque, target_phys_addr_t addr)
|
|
{
|
|
SerialState *s = opaque;
|
|
|
|
return serial_ioport_read(s, addr >> s->it_shift) & 0xFF;
|
|
}
|
|
|
|
void serial_mm_writeb (void *opaque,
|
|
target_phys_addr_t addr, uint32_t value)
|
|
{
|
|
SerialState *s = opaque;
|
|
|
|
serial_ioport_write(s, addr >> s->it_shift, value & 0xFF);
|
|
}
|
|
|
|
uint32_t serial_mm_readw (void *opaque, target_phys_addr_t addr)
|
|
{
|
|
SerialState *s = opaque;
|
|
uint32_t val;
|
|
|
|
val = serial_ioport_read(s, addr >> s->it_shift) & 0xFFFF;
|
|
#ifdef TARGET_WORDS_BIGENDIAN
|
|
val = bswap16(val);
|
|
#endif
|
|
return val;
|
|
}
|
|
|
|
void serial_mm_writew (void *opaque,
|
|
target_phys_addr_t addr, uint32_t value)
|
|
{
|
|
SerialState *s = opaque;
|
|
#ifdef TARGET_WORDS_BIGENDIAN
|
|
value = bswap16(value);
|
|
#endif
|
|
serial_ioport_write(s, addr >> s->it_shift, value & 0xFFFF);
|
|
}
|
|
|
|
uint32_t serial_mm_readl (void *opaque, target_phys_addr_t addr)
|
|
{
|
|
SerialState *s = opaque;
|
|
uint32_t val;
|
|
|
|
val = serial_ioport_read(s, addr >> s->it_shift);
|
|
#ifdef TARGET_WORDS_BIGENDIAN
|
|
val = bswap32(val);
|
|
#endif
|
|
return val;
|
|
}
|
|
|
|
void serial_mm_writel (void *opaque,
|
|
target_phys_addr_t addr, uint32_t value)
|
|
{
|
|
SerialState *s = opaque;
|
|
#ifdef TARGET_WORDS_BIGENDIAN
|
|
value = bswap32(value);
|
|
#endif
|
|
serial_ioport_write(s, addr >> s->it_shift, value);
|
|
}
|
|
|
|
static CPUReadMemoryFunc *serial_mm_read[] = {
|
|
&serial_mm_readb,
|
|
&serial_mm_readw,
|
|
&serial_mm_readl,
|
|
};
|
|
|
|
static CPUWriteMemoryFunc *serial_mm_write[] = {
|
|
&serial_mm_writeb,
|
|
&serial_mm_writew,
|
|
&serial_mm_writel,
|
|
};
|
|
|
|
SerialState *serial_mm_init (target_phys_addr_t base, int it_shift,
|
|
qemu_irq irq, int baudbase,
|
|
CharDriverState *chr, int ioregister)
|
|
{
|
|
SerialState *s;
|
|
int s_io_memory;
|
|
|
|
s = qemu_mallocz(sizeof(SerialState));
|
|
if (!s)
|
|
return NULL;
|
|
|
|
s->it_shift = it_shift;
|
|
|
|
serial_init_core(s, irq, baudbase, chr);
|
|
register_savevm("serial", base, 3, serial_save, serial_load, s);
|
|
|
|
if (ioregister) {
|
|
s_io_memory = cpu_register_io_memory(0, serial_mm_read,
|
|
serial_mm_write, s);
|
|
cpu_register_physical_memory(base, 8 << it_shift, s_io_memory);
|
|
}
|
|
qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
|
|
serial_event, s);
|
|
serial_update_msl(s);
|
|
return s;
|
|
}
|