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xemu/hw/serial.c
Michael Tokarev b37a2e4576 Revert "serial: fix retry logic" 
This reverts commit 67c5322d70:

    I'm not sure if the retry logic has ever worked when not using FIFO mode.  I
    found this while writing a test case although code inspection confirms it is
    definitely broken.

    The TSR retry logic will never actually happen because it is guarded by an
    'if (s->tsr_rety > 0)' but this is the only place that can ever make the
    variable greater than zero.  That effectively makes the retry logic an 'if (0)

    I believe this is a typo and the intention was >= 0.  Once this is fixed thoug
    I see double transmits with my test case.  This is because in the non FIFO
    case, serial_xmit may get invoked while LSR.THRE is still high because the
    character was processed but the retransmit timer was still active.

    We can handle this by simply checking for LSR.THRE and returning early.  It's
    possible that the FIFO paths also need some attention.

    Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Even if the previous logic was never worked, new logic breaks stuff -
namely,

 qemu -enable-kvm -nographic -kernel /boot/vmlinuz-$(uname -r) -append console=ttyS0 -serial pty

the above command will cause the virtual machine to stuck at startup
using 100% CPU till one connects to the pty and sends any char to it.

Note this is rather typical invocation for various headless virtual
machines by libvirt.

So revert this change for now, till a better solution will be found.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-01-24 09:45:03 -06:00

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/*
* 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 "serial.h"
#include "char/char.h"
#include "qemu/timer.h"
#include "exec/address-spaces.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 XMIT_FIFO 0
#define RECV_FIFO 1
#define MAX_XMIT_RETRY 4
#ifdef DEBUG_SERIAL
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, "serial: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do {} while (0)
#endif
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;
/* Receive overruns do not overwrite FIFO contents. */
if (fifo == XMIT_FIFO || f->count < UART_FIFO_LENGTH) {
f->data[f->head++] = chr;
if (f->head == UART_FIFO_LENGTH)
f->head = 0;
}
if (f->count < UART_FIFO_LENGTH)
f->count++;
else if (fifo == RECV_FIFO)
s->lsr |= UART_LSR_OE;
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) &&
(!(s->fcr & UART_FCR_FE) ||
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;
/* Start bit. */
frame_size = 1;
if (s->lcr & 0x08) {
/* Parity bit. */
frame_size++;
if (s->lcr & 0x10)
parity = 'E';
else
parity = 'O';
} else {
parity = 'N';
}
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 = (get_ticks_per_sec() / speed) * frame_size;
qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
DPRINTF("speed=%d parity=%c data=%d stop=%d\n",
speed, parity, data_bits, stop_bits);
}
static void serial_update_msl(SerialState *s)
{
uint8_t omsr;
int flags;
qemu_del_timer(s->modem_status_poll);
if (qemu_chr_fe_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_ns(vm_clock) + get_ticks_per_sec() / 100);
}
static void serial_xmit(void *opaque)
{
SerialState *s = opaque;
uint64_t new_xmit_ts = qemu_get_clock_ns(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;
s->lsr &= ~UART_LSR_TEMT;
}
}
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_fe_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_ns(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, hwaddr addr, uint64_t val,
unsigned size)
{
SerialState *s = opaque;
addr &= 7;
DPRINTF("write addr=0x%02x val=0x%02x\n", addr, val);
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_fe_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_fe_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_fe_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_ns(vm_clock) + s->char_transmit_time);
}
}
break;
case 5:
break;
case 6:
break;
case 7:
s->scr = val;
break;
}
}
static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size)
{
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_ns (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;
if ((ret & UART_IIR_ID) == UART_IIR_THRI) {
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 and overrun interrupts */
if (s->lsr & (UART_LSR_BI|UART_LSR_OE)) {
s->lsr &= ~(UART_LSR_BI|UART_LSR_OE);
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;
}
DPRINTF("read addr=0x%02x val=0x%02x\n", addr, ret);
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;
/* When the LSR_DR is set a null byte is pushed into the fifo */
fifo_put(s, RECV_FIFO, '\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->wakeup) {
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
}
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_ns (vm_clock) + s->char_transmit_time * 4);
} else {
if (s->lsr & UART_LSR_DR)
s->lsr |= UART_LSR_OE;
s->rbr = buf[0];
s->lsr |= UART_LSR_DR;
}
serial_update_irq(s);
}
static void serial_event(void *opaque, int event)
{
SerialState *s = opaque;
DPRINTF("event %x\n", event);
if (event == CHR_EVENT_BREAK)
serial_receive_break(s);
}
static void serial_pre_save(void *opaque)
{
SerialState *s = opaque;
s->fcr_vmstate = s->fcr;
}
static int serial_post_load(void *opaque, int version_id)
{
SerialState *s = opaque;
if (version_id < 3) {
s->fcr_vmstate = 0;
}
/* Initialize fcr via setter to perform essential side-effects */
serial_ioport_write(s, 0x02, s->fcr_vmstate, 1);
serial_update_parameters(s);
return 0;
}
const VMStateDescription vmstate_serial = {
.name = "serial",
.version_id = 3,
.minimum_version_id = 2,
.pre_save = serial_pre_save,
.post_load = serial_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT16_V(divider, SerialState, 2),
VMSTATE_UINT8(rbr, SerialState),
VMSTATE_UINT8(ier, SerialState),
VMSTATE_UINT8(iir, SerialState),
VMSTATE_UINT8(lcr, SerialState),
VMSTATE_UINT8(mcr, SerialState),
VMSTATE_UINT8(lsr, SerialState),
VMSTATE_UINT8(msr, SerialState),
VMSTATE_UINT8(scr, SerialState),
VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
VMSTATE_END_OF_LIST()
}
};
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, 1 start bit, 8 data bits, 1 stop bit, no parity. */
s->divider = 0x0C;
s->mcr = UART_MCR_OUT2;
s->scr = 0;
s->tsr_retry = 0;
s->char_transmit_time = (get_ticks_per_sec() / 9600) * 10;
s->poll_msl = 0;
fifo_clear(s,RECV_FIFO);
fifo_clear(s,XMIT_FIFO);
s->last_xmit_ts = qemu_get_clock_ns(vm_clock);
s->thr_ipending = 0;
s->last_break_enable = 0;
qemu_irq_lower(s->irq);
}
void serial_init_core(SerialState *s)
{
if (!s->chr) {
fprintf(stderr, "Can't create serial device, empty char device\n");
exit(1);
}
s->modem_status_poll = qemu_new_timer_ns(vm_clock, (QEMUTimerCB *) serial_update_msl, s);
s->fifo_timeout_timer = qemu_new_timer_ns(vm_clock, (QEMUTimerCB *) fifo_timeout_int, s);
s->transmit_timer = qemu_new_timer_ns(vm_clock, (QEMUTimerCB *) serial_xmit, s);
qemu_register_reset(serial_reset, s);
qemu_chr_add_handlers(s->chr, serial_can_receive1, serial_receive1,
serial_event, s);
}
void serial_exit_core(SerialState *s)
{
qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
qemu_unregister_reset(serial_reset, s);
}
/* Change the main reference oscillator frequency. */
void serial_set_frequency(SerialState *s, uint32_t frequency)
{
s->baudbase = frequency;
serial_update_parameters(s);
}
const MemoryRegionOps serial_io_ops = {
.read = serial_ioport_read,
.write = serial_ioport_write,
.impl = {
.min_access_size = 1,
.max_access_size = 1,
},
.endianness = DEVICE_LITTLE_ENDIAN,
};
SerialState *serial_init(int base, qemu_irq irq, int baudbase,
CharDriverState *chr, MemoryRegion *system_io)
{
SerialState *s;
s = g_malloc0(sizeof(SerialState));
s->irq = irq;
s->baudbase = baudbase;
s->chr = chr;
serial_init_core(s);
vmstate_register(NULL, base, &vmstate_serial, s);
memory_region_init_io(&s->io, &serial_io_ops, s, "serial", 8);
memory_region_add_subregion(system_io, base, &s->io);
return s;
}
/* Memory mapped interface */
static uint64_t serial_mm_read(void *opaque, hwaddr addr,
unsigned size)
{
SerialState *s = opaque;
return serial_ioport_read(s, addr >> s->it_shift, 1);
}
static void serial_mm_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
SerialState *s = opaque;
value &= ~0u >> (32 - (size * 8));
serial_ioport_write(s, addr >> s->it_shift, value, 1);
}
static const MemoryRegionOps serial_mm_ops[3] = {
[DEVICE_NATIVE_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_NATIVE_ENDIAN,
},
[DEVICE_LITTLE_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_LITTLE_ENDIAN,
},
[DEVICE_BIG_ENDIAN] = {
.read = serial_mm_read,
.write = serial_mm_write,
.endianness = DEVICE_BIG_ENDIAN,
},
};
SerialState *serial_mm_init(MemoryRegion *address_space,
hwaddr base, int it_shift,
qemu_irq irq, int baudbase,
CharDriverState *chr, enum device_endian end)
{
SerialState *s;
s = g_malloc0(sizeof(SerialState));
s->it_shift = it_shift;
s->irq = irq;
s->baudbase = baudbase;
s->chr = chr;
serial_init_core(s);
vmstate_register(NULL, base, &vmstate_serial, s);
memory_region_init_io(&s->io, &serial_mm_ops[end], s,
"serial", 8 << it_shift);
memory_region_add_subregion(address_space, base, &s->io);
serial_update_msl(s);
return s;
}
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