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qemu-e2k/hw/cadence_uart.c
Peter Crosthwaite 9893c80d81 cadance_uart: Accept input after rx FIFO pop 
The device returns false from the can receive function when the FIFO is
full. This means the device should check for buffered input whenever a byte is
popped from the FIFO.

Reported-by: Jason Wu <huanyu@xilinx.com>
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1360632571-25638-1-git-send-email-peter.crosthwaite@xilinx.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-13 11:57:58 -06:00

518 lines
13 KiB
C
Raw Blame History

/*
* Device model for Cadence UART
*
* Copyright (c) 2010 Xilinx Inc.
* Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
* Copyright (c) 2012 PetaLogix Pty Ltd.
* Written by Haibing Ma
* M.Habib
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "sysbus.h"
#include "char/char.h"
#include "qemu/timer.h"
#ifdef CADENCE_UART_ERR_DEBUG
#define DB_PRINT(...) do { \
fprintf(stderr, ": %s: ", __func__); \
fprintf(stderr, ## __VA_ARGS__); \
} while (0);
#else
#define DB_PRINT(...)
#endif
#define UART_SR_INTR_RTRIG 0x00000001
#define UART_SR_INTR_REMPTY 0x00000002
#define UART_SR_INTR_RFUL 0x00000004
#define UART_SR_INTR_TEMPTY 0x00000008
#define UART_SR_INTR_TFUL 0x00000010
/* bits fields in CSR that correlate to CISR. If any of these bits are set in
* SR, then the same bit in CISR is set high too */
#define UART_SR_TO_CISR_MASK 0x0000001F
#define UART_INTR_ROVR 0x00000020
#define UART_INTR_FRAME 0x00000040
#define UART_INTR_PARE 0x00000080
#define UART_INTR_TIMEOUT 0x00000100
#define UART_INTR_DMSI 0x00000200
#define UART_SR_RACTIVE 0x00000400
#define UART_SR_TACTIVE 0x00000800
#define UART_SR_FDELT 0x00001000
#define UART_CR_RXRST 0x00000001
#define UART_CR_TXRST 0x00000002
#define UART_CR_RX_EN 0x00000004
#define UART_CR_RX_DIS 0x00000008
#define UART_CR_TX_EN 0x00000010
#define UART_CR_TX_DIS 0x00000020
#define UART_CR_RST_TO 0x00000040
#define UART_CR_STARTBRK 0x00000080
#define UART_CR_STOPBRK 0x00000100
#define UART_MR_CLKS 0x00000001
#define UART_MR_CHRL 0x00000006
#define UART_MR_CHRL_SH 1
#define UART_MR_PAR 0x00000038
#define UART_MR_PAR_SH 3
#define UART_MR_NBSTOP 0x000000C0
#define UART_MR_NBSTOP_SH 6
#define UART_MR_CHMODE 0x00000300
#define UART_MR_CHMODE_SH 8
#define UART_MR_UCLKEN 0x00000400
#define UART_MR_IRMODE 0x00000800
#define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH)
#define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH)
#define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH)
#define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH)
#define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH)
#define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH)
#define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH)
#define ECHO_MODE (0x1 << UART_MR_CHMODE_SH)
#define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH)
#define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH)
#define RX_FIFO_SIZE 16
#define TX_FIFO_SIZE 16
#define UART_INPUT_CLK 50000000
#define R_CR (0x00/4)
#define R_MR (0x04/4)
#define R_IER (0x08/4)
#define R_IDR (0x0C/4)
#define R_IMR (0x10/4)
#define R_CISR (0x14/4)
#define R_BRGR (0x18/4)
#define R_RTOR (0x1C/4)
#define R_RTRIG (0x20/4)
#define R_MCR (0x24/4)
#define R_MSR (0x28/4)
#define R_SR (0x2C/4)
#define R_TX_RX (0x30/4)
#define R_BDIV (0x34/4)
#define R_FDEL (0x38/4)
#define R_PMIN (0x3C/4)
#define R_PWID (0x40/4)
#define R_TTRIG (0x44/4)
#define R_MAX (R_TTRIG + 1)
typedef struct {
SysBusDevice busdev;
MemoryRegion iomem;
uint32_t r[R_MAX];
uint8_t r_fifo[RX_FIFO_SIZE];
uint32_t rx_wpos;
uint32_t rx_count;
uint64_t char_tx_time;
CharDriverState *chr;
qemu_irq irq;
struct QEMUTimer *fifo_trigger_handle;
struct QEMUTimer *tx_time_handle;
} UartState;
static void uart_update_status(UartState *s)
{
s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK;
qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR]));
}
static void fifo_trigger_update(void *opaque)
{
UartState *s = (UartState *)opaque;
s->r[R_CISR] |= UART_INTR_TIMEOUT;
uart_update_status(s);
}
static void uart_tx_redo(UartState *s)
{
uint64_t new_tx_time = qemu_get_clock_ns(vm_clock);
qemu_mod_timer(s->tx_time_handle, new_tx_time + s->char_tx_time);
s->r[R_SR] |= UART_SR_INTR_TEMPTY;
uart_update_status(s);
}
static void uart_tx_write(void *opaque)
{
UartState *s = (UartState *)opaque;
uart_tx_redo(s);
}
static void uart_rx_reset(UartState *s)
{
s->rx_wpos = 0;
s->rx_count = 0;
s->r[R_SR] |= UART_SR_INTR_REMPTY;
s->r[R_SR] &= ~UART_SR_INTR_RFUL;
}
static void uart_tx_reset(UartState *s)
{
s->r[R_SR] |= UART_SR_INTR_TEMPTY;
s->r[R_SR] &= ~UART_SR_INTR_TFUL;
}
static void uart_send_breaks(UartState *s)
{
int break_enabled = 1;
qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
&break_enabled);
}
static void uart_parameters_setup(UartState *s)
{
QEMUSerialSetParams ssp;
unsigned int baud_rate, packet_size;
baud_rate = (s->r[R_MR] & UART_MR_CLKS) ?
UART_INPUT_CLK / 8 : UART_INPUT_CLK;
ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1));
packet_size = 1;
switch (s->r[R_MR] & UART_MR_PAR) {
case UART_PARITY_EVEN:
ssp.parity = 'E';
packet_size++;
break;
case UART_PARITY_ODD:
ssp.parity = 'O';
packet_size++;
break;
default:
ssp.parity = 'N';
break;
}
switch (s->r[R_MR] & UART_MR_CHRL) {
case UART_DATA_BITS_6:
ssp.data_bits = 6;
break;
case UART_DATA_BITS_7:
ssp.data_bits = 7;
break;
default:
ssp.data_bits = 8;
break;
}
switch (s->r[R_MR] & UART_MR_NBSTOP) {
case UART_STOP_BITS_1:
ssp.stop_bits = 1;
break;
default:
ssp.stop_bits = 2;
break;
}
packet_size += ssp.data_bits + ssp.stop_bits;
s->char_tx_time = (get_ticks_per_sec() / ssp.speed) * packet_size;
qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
}
static int uart_can_receive(void *opaque)
{
UartState *s = (UartState *)opaque;
return RX_FIFO_SIZE - s->rx_count;
}
static void uart_ctrl_update(UartState *s)
{
if (s->r[R_CR] & UART_CR_TXRST) {
uart_tx_reset(s);
}
if (s->r[R_CR] & UART_CR_RXRST) {
uart_rx_reset(s);
}
s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST);
if ((s->r[R_CR] & UART_CR_TX_EN) && !(s->r[R_CR] & UART_CR_TX_DIS)) {
uart_tx_redo(s);
}
if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) {
uart_send_breaks(s);
}
}
static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
{
UartState *s = (UartState *)opaque;
uint64_t new_rx_time = qemu_get_clock_ns(vm_clock);
int i;
if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
return;
}
s->r[R_SR] &= ~UART_SR_INTR_REMPTY;
if (s->rx_count == RX_FIFO_SIZE) {
s->r[R_CISR] |= UART_INTR_ROVR;
} else {
for (i = 0; i < size; i++) {
s->r_fifo[s->rx_wpos] = buf[i];
s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE;
s->rx_count++;
if (s->rx_count == RX_FIFO_SIZE) {
s->r[R_SR] |= UART_SR_INTR_RFUL;
break;
}
if (s->rx_count >= s->r[R_RTRIG]) {
s->r[R_SR] |= UART_SR_INTR_RTRIG;
}
}
qemu_mod_timer(s->fifo_trigger_handle, new_rx_time +
(s->char_tx_time * 4));
}
uart_update_status(s);
}
static void uart_write_tx_fifo(UartState *s, const uint8_t *buf, int size)
{
if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) {
return;
}
while (size) {
size -= qemu_chr_fe_write(s->chr, buf, size);
}
}
static void uart_receive(void *opaque, const uint8_t *buf, int size)
{
UartState *s = (UartState *)opaque;
uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
uart_write_rx_fifo(opaque, buf, size);
}
if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
uart_write_tx_fifo(s, buf, size);
}
}
static void uart_event(void *opaque, int event)
{
UartState *s = (UartState *)opaque;
uint8_t buf = '\0';
if (event == CHR_EVENT_BREAK) {
uart_write_rx_fifo(opaque, &buf, 1);
}
uart_update_status(s);
}
static void uart_read_rx_fifo(UartState *s, uint32_t *c)
{
if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
return;
}
s->r[R_SR] &= ~UART_SR_INTR_RFUL;
if (s->rx_count) {
uint32_t rx_rpos =
(RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE;
*c = s->r_fifo[rx_rpos];
s->rx_count--;
if (!s->rx_count) {
s->r[R_SR] |= UART_SR_INTR_REMPTY;
}
qemu_chr_accept_input(s->chr);
} else {
*c = 0;
s->r[R_SR] |= UART_SR_INTR_REMPTY;
}
if (s->rx_count < s->r[R_RTRIG]) {
s->r[R_SR] &= ~UART_SR_INTR_RTRIG;
}
uart_update_status(s);
}
static void uart_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
UartState *s = (UartState *)opaque;
DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value);
offset >>= 2;
switch (offset) {
case R_IER: /* ier (wts imr) */
s->r[R_IMR] |= value;
break;
case R_IDR: /* idr (wtc imr) */
s->r[R_IMR] &= ~value;
break;
case R_IMR: /* imr (read only) */
break;
case R_CISR: /* cisr (wtc) */
s->r[R_CISR] &= ~value;
break;
case R_TX_RX: /* UARTDR */
switch (s->r[R_MR] & UART_MR_CHMODE) {
case NORMAL_MODE:
uart_write_tx_fifo(s, (uint8_t *) &value, 1);
break;
case LOCAL_LOOPBACK:
uart_write_rx_fifo(opaque, (uint8_t *) &value, 1);
break;
}
break;
default:
s->r[offset] = value;
}
switch (offset) {
case R_CR:
uart_ctrl_update(s);
break;
case R_MR:
uart_parameters_setup(s);
break;
}
}
static uint64_t uart_read(void *opaque, hwaddr offset,
unsigned size)
{
UartState *s = (UartState *)opaque;
uint32_t c = 0;
offset >>= 2;
if (offset >= R_MAX) {
c = 0;
} else if (offset == R_TX_RX) {
uart_read_rx_fifo(s, &c);
} else {
c = s->r[offset];
}
DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c);
return c;
}
static const MemoryRegionOps uart_ops = {
.read = uart_read,
.write = uart_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void cadence_uart_reset(UartState *s)
{
s->r[R_CR] = 0x00000128;
s->r[R_IMR] = 0;
s->r[R_CISR] = 0;
s->r[R_RTRIG] = 0x00000020;
s->r[R_BRGR] = 0x0000000F;
s->r[R_TTRIG] = 0x00000020;
uart_rx_reset(s);
uart_tx_reset(s);
s->rx_count = 0;
s->rx_wpos = 0;
}
static int cadence_uart_init(SysBusDevice *dev)
{
UartState *s = FROM_SYSBUS(UartState, dev);
memory_region_init_io(&s->iomem, &uart_ops, s, "uart", 0x1000);
sysbus_init_mmio(dev, &s->iomem);
sysbus_init_irq(dev, &s->irq);
s->fifo_trigger_handle = qemu_new_timer_ns(vm_clock,
(QEMUTimerCB *)fifo_trigger_update, s);
s->tx_time_handle = qemu_new_timer_ns(vm_clock,
(QEMUTimerCB *)uart_tx_write, s);
s->char_tx_time = (get_ticks_per_sec() / 9600) * 10;
s->chr = qemu_char_get_next_serial();
cadence_uart_reset(s);
if (s->chr) {
qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive,
uart_event, s);
}
return 0;
}
static int cadence_uart_post_load(void *opaque, int version_id)
{
UartState *s = opaque;
uart_parameters_setup(s);
uart_update_status(s);
return 0;
}
static const VMStateDescription vmstate_cadence_uart = {
.name = "cadence_uart",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.post_load = cadence_uart_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(r, UartState, R_MAX),
VMSTATE_UINT8_ARRAY(r_fifo, UartState, RX_FIFO_SIZE),
VMSTATE_UINT32(rx_count, UartState),
VMSTATE_UINT32(rx_wpos, UartState),
VMSTATE_TIMER(fifo_trigger_handle, UartState),
VMSTATE_TIMER(tx_time_handle, UartState),
VMSTATE_END_OF_LIST()
}
};
static void cadence_uart_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
sdc->init = cadence_uart_init;
dc->vmsd = &vmstate_cadence_uart;
}
static const TypeInfo cadence_uart_info = {
.name = "cadence_uart",
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(UartState),
.class_init = cadence_uart_class_init,
};
static void cadence_uart_register_types(void)
{
type_register_static(&cadence_uart_info);
}
type_init(cadence_uart_register_types)
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