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authorYang Zhang <yang.z.zhang@intel.com>2015-08-28 09:58:54 +0800
committerYang Zhang <yang.z.zhang@intel.com>2015-09-01 12:44:00 +0800
commite44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch)
tree66b09f592c55df2878107a468a91d21506104d3f /qemu/hw/char/serial.c
parent9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff)
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/hw/char/serial.c')
-rw-r--r--qemu/hw/char/serial.c972
1 files changed, 972 insertions, 0 deletions
diff --git a/qemu/hw/char/serial.c b/qemu/hw/char/serial.c
new file mode 100644
index 000000000..513d73c27
--- /dev/null
+++ b/qemu/hw/char/serial.c
@@ -0,0 +1,972 @@
+/*
+ * 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/char/serial.h"
+#include "sysemu/char.h"
+#include "qemu/timer.h"
+#include "exec/address-spaces.h"
+#include "qemu/error-report.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 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 inline void recv_fifo_put(SerialState *s, uint8_t chr)
+{
+ /* Receive overruns do not overwrite FIFO contents. */
+ if (!fifo8_is_full(&s->recv_fifo)) {
+ fifo8_push(&s->recv_fifo, chr);
+ } else {
+ s->lsr |= UART_LSR_OE;
+ }
+}
+
+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.num >= 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;
+
+ timer_del(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)
+ timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + get_ticks_per_sec() / 100);
+}
+
+static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque)
+{
+ SerialState *s = opaque;
+
+ do {
+ assert(!(s->lsr & UART_LSR_TEMT));
+ if (s->tsr_retry <= 0) {
+ assert(!(s->lsr & UART_LSR_THRE));
+
+ if (s->fcr & UART_FCR_FE) {
+ assert(!fifo8_is_empty(&s->xmit_fifo));
+ s->tsr = fifo8_pop(&s->xmit_fifo);
+ if (!s->xmit_fifo.num) {
+ s->lsr |= UART_LSR_THRE;
+ }
+ } else {
+ s->tsr = s->thr;
+ s->lsr |= UART_LSR_THRE;
+ }
+ if ((s->lsr & UART_LSR_THRE) && !s->thr_ipending) {
+ s->thr_ipending = 1;
+ serial_update_irq(s);
+ }
+ }
+
+ 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 &&
+ qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP,
+ serial_xmit, s) > 0) {
+ s->tsr_retry++;
+ return FALSE;
+ }
+ s->tsr_retry = 0;
+ } else {
+ s->tsr_retry = 0;
+ }
+
+ /* Transmit another byte if it is already available. It is only
+ possible when FIFO is enabled and not empty. */
+ } while (!(s->lsr & UART_LSR_THRE));
+
+ s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ s->lsr |= UART_LSR_TEMT;
+
+ return FALSE;
+}
+
+
+/* Setter for FCR.
+ is_load flag means, that value is set while loading VM state
+ and interrupt should not be invoked */
+static void serial_write_fcr(SerialState *s, uint8_t val)
+{
+ /* Set fcr - val only has the bits that are supposed to "stick" */
+ s->fcr = val;
+
+ 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;
+ }
+}
+
+static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
+ unsigned size)
+{
+ SerialState *s = opaque;
+
+ addr &= 7;
+ DPRINTF("write addr=0x%" HWADDR_PRIx " val=0x%" PRIx64 "\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) {
+ /* xmit overruns overwrite data, so make space if needed */
+ if (fifo8_is_full(&s->xmit_fifo)) {
+ fifo8_pop(&s->xmit_fifo);
+ }
+ fifo8_push(&s->xmit_fifo, s->thr);
+ }
+ s->thr_ipending = 0;
+ s->lsr &= ~UART_LSR_THRE;
+ s->lsr &= ~UART_LSR_TEMT;
+ serial_update_irq(s);
+ if (s->tsr_retry <= 0) {
+ serial_xmit(NULL, G_IO_OUT, s);
+ }
+ }
+ break;
+ case 1:
+ if (s->lcr & UART_LCR_DLAB) {
+ s->divider = (s->divider & 0x00ff) | (val << 8);
+ serial_update_parameters(s);
+ } else {
+ uint8_t changed = (s->ier ^ val) & 0x0f;
+ 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 ((changed & UART_IER_MSI) && s->poll_msl >= 0) {
+ if (s->ier & UART_IER_MSI) {
+ s->poll_msl = 1;
+ serial_update_msl(s);
+ } else {
+ timer_del(s->modem_status_poll);
+ s->poll_msl = 0;
+ }
+ }
+
+ /* Turning on the THRE interrupt on IER can trigger the interrupt
+ * if LSR.THRE=1, even if it had been masked before by reading IIR.
+ * This is not in the datasheet, but Windows relies on it. It is
+ * unclear if THRE has to be resampled every time THRI becomes
+ * 1, or only on the rising edge. Bochs does the latter, and Windows
+ * always toggles IER to all zeroes and back to all ones, so do the
+ * same.
+ *
+ * If IER.THRI is zero, thr_ipending is not used. Set it to zero
+ * so that the thr_ipending subsection is not migrated.
+ */
+ if (changed & UART_IER_THRI) {
+ if ((s->ier & UART_IER_THRI) && (s->lsr & UART_LSR_THRE)) {
+ s->thr_ipending = 1;
+ } else {
+ s->thr_ipending = 0;
+ }
+ }
+
+ if (changed) {
+ serial_update_irq(s);
+ }
+ }
+ break;
+ case 2:
+ /* 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) {
+ s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ timer_del(s->fifo_timeout_timer);
+ s->timeout_ipending = 0;
+ fifo8_reset(&s->recv_fifo);
+ }
+
+ if (val & UART_FCR_XFR) {
+ s->lsr |= UART_LSR_THRE;
+ s->thr_ipending = 1;
+ fifo8_reset(&s->xmit_fifo);
+ }
+
+ serial_write_fcr(s, 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 */
+ timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 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 = fifo8_is_empty(&s->recv_fifo) ?
+ 0 : fifo8_pop(&s->recv_fifo);
+ if (s->recv_fifo.num == 0) {
+ s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ } else {
+ timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 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%" HWADDR_PRIx " 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.num < 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.num <= s->recv_fifo_itl) ?
+ s->recv_fifo_itl - s->recv_fifo.num : 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 */
+ recv_fifo_put(s, '\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.num) {
+ 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++) {
+ recv_fifo_put(s, buf[i]);
+ }
+ s->lsr |= UART_LSR_DR;
+ /* call the timeout receive callback in 4 char transmit time */
+ timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 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_pre_load(void *opaque)
+{
+ SerialState *s = opaque;
+ s->thr_ipending = -1;
+ s->poll_msl = -1;
+ return 0;
+}
+
+static int serial_post_load(void *opaque, int version_id)
+{
+ SerialState *s = opaque;
+
+ if (version_id < 3) {
+ s->fcr_vmstate = 0;
+ }
+ if (s->thr_ipending == -1) {
+ s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
+ }
+ s->last_break_enable = (s->lcr >> 6) & 1;
+ /* Initialize fcr via setter to perform essential side-effects */
+ serial_write_fcr(s, s->fcr_vmstate);
+ serial_update_parameters(s);
+ return 0;
+}
+
+static bool serial_thr_ipending_needed(void *opaque)
+{
+ SerialState *s = opaque;
+
+ if (s->ier & UART_IER_THRI) {
+ bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
+ return s->thr_ipending != expected_value;
+ } else {
+ /* LSR.THRE will be sampled again when the interrupt is
+ * enabled. thr_ipending is not used in this case, do
+ * not migrate it.
+ */
+ return false;
+ }
+}
+
+static const VMStateDescription vmstate_serial_thr_ipending = {
+ .name = "serial/thr_ipending",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_thr_ipending_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT32(thr_ipending, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_tsr_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return s->tsr_retry != 0;
+}
+
+static const VMStateDescription vmstate_serial_tsr = {
+ .name = "serial/tsr",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_tsr_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT32(tsr_retry, SerialState),
+ VMSTATE_UINT8(thr, SerialState),
+ VMSTATE_UINT8(tsr, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_recv_fifo_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return !fifo8_is_empty(&s->recv_fifo);
+
+}
+
+static const VMStateDescription vmstate_serial_recv_fifo = {
+ .name = "serial/recv_fifo",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_recv_fifo_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_xmit_fifo_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return !fifo8_is_empty(&s->xmit_fifo);
+}
+
+static const VMStateDescription vmstate_serial_xmit_fifo = {
+ .name = "serial/xmit_fifo",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_xmit_fifo_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_fifo_timeout_timer_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return timer_pending(s->fifo_timeout_timer);
+}
+
+static const VMStateDescription vmstate_serial_fifo_timeout_timer = {
+ .name = "serial/fifo_timeout_timer",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_fifo_timeout_timer_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_TIMER_PTR(fifo_timeout_timer, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_timeout_ipending_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return s->timeout_ipending != 0;
+}
+
+static const VMStateDescription vmstate_serial_timeout_ipending = {
+ .name = "serial/timeout_ipending",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = serial_timeout_ipending_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT32(timeout_ipending, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool serial_poll_needed(void *opaque)
+{
+ SerialState *s = (SerialState *)opaque;
+ return s->poll_msl >= 0;
+}
+
+static const VMStateDescription vmstate_serial_poll = {
+ .name = "serial/poll",
+ .version_id = 1,
+ .needed = serial_poll_needed,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT32(poll_msl, SerialState),
+ VMSTATE_TIMER_PTR(modem_status_poll, SerialState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+const VMStateDescription vmstate_serial = {
+ .name = "serial",
+ .version_id = 3,
+ .minimum_version_id = 2,
+ .pre_save = serial_pre_save,
+ .pre_load = serial_pre_load,
+ .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()
+ },
+ .subsections = (const VMStateDescription*[]) {
+ &vmstate_serial_thr_ipending,
+ &vmstate_serial_tsr,
+ &vmstate_serial_recv_fifo,
+ &vmstate_serial_xmit_fifo,
+ &vmstate_serial_fifo_timeout_timer,
+ &vmstate_serial_timeout_ipending,
+ &vmstate_serial_poll,
+ NULL
+ }
+};
+
+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;
+
+ s->timeout_ipending = 0;
+ timer_del(s->fifo_timeout_timer);
+ timer_del(s->modem_status_poll);
+
+ fifo8_reset(&s->recv_fifo);
+ fifo8_reset(&s->xmit_fifo);
+
+ s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+ s->thr_ipending = 0;
+ s->last_break_enable = 0;
+ qemu_irq_lower(s->irq);
+
+ serial_update_msl(s);
+ s->msr &= ~UART_MSR_ANY_DELTA;
+}
+
+void serial_realize_core(SerialState *s, Error **errp)
+{
+ if (!s->chr) {
+ error_setg(errp, "Can't create serial device, empty char device");
+ return;
+ }
+
+ s->modem_status_poll = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) serial_update_msl, s);
+
+ s->fifo_timeout_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) fifo_timeout_int, s);
+ qemu_register_reset(serial_reset, s);
+
+ qemu_chr_add_handlers(s->chr, serial_can_receive1, serial_receive1,
+ serial_event, s);
+ fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH);
+ fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH);
+ serial_reset(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;
+ Error *err = NULL;
+
+ s = g_malloc0(sizeof(SerialState));
+
+ s->irq = irq;
+ s->baudbase = baudbase;
+ s->chr = chr;
+ serial_realize_core(s, &err);
+ if (err != NULL) {
+ error_report_err(err);
+ exit(1);
+ }
+
+ vmstate_register(NULL, base, &vmstate_serial, s);
+
+ memory_region_init_io(&s->io, NULL, &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;
+ Error *err = NULL;
+
+ s = g_malloc0(sizeof(SerialState));
+
+ s->it_shift = it_shift;
+ s->irq = irq;
+ s->baudbase = baudbase;
+ s->chr = chr;
+
+ serial_realize_core(s, &err);
+ if (err != NULL) {
+ error_report_err(err);
+ exit(1);
+ }
+ vmstate_register(NULL, base, &vmstate_serial, s);
+
+ memory_region_init_io(&s->io, NULL, &serial_mm_ops[end], s,
+ "serial", 8 << it_shift);
+ memory_region_add_subregion(address_space, base, &s->io);
+ return s;
+}