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qemu/hw/char/exynos4210_uart.c

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/*
* Exynos4210 UART Emulation
*
* Copyright (C) 2011 Samsung Electronics Co Ltd.
* Maksim Kozlov, <m.kozlov@samsung.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* 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 "qemu/osdep.h"
#include "hw/sysbus.h"
#include "qemu/error-report.h"
#include "sysemu/sysemu.h"
#include "chardev/char-fe.h"
#include "chardev/char-serial.h"
#include "hw/arm/exynos4210.h"
#undef DEBUG_UART
#undef DEBUG_UART_EXTEND
#undef DEBUG_IRQ
#undef DEBUG_Rx_DATA
#undef DEBUG_Tx_DATA
#define DEBUG_UART 0
#define DEBUG_UART_EXTEND 0
#define DEBUG_IRQ 0
#define DEBUG_Rx_DATA 0
#define DEBUG_Tx_DATA 0
#if DEBUG_UART
#define PRINT_DEBUG(fmt, args...) \
do { \
fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
} while (0)
#if DEBUG_UART_EXTEND
#define PRINT_DEBUG_EXTEND(fmt, args...) \
do { \
fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
} while (0)
#else
#define PRINT_DEBUG_EXTEND(fmt, args...) \
do {} while (0)
#endif /* EXTEND */
#else
#define PRINT_DEBUG(fmt, args...) \
do {} while (0)
#define PRINT_DEBUG_EXTEND(fmt, args...) \
do {} while (0)
#endif
#define PRINT_ERROR(fmt, args...) \
do { \
fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
} while (0)
/*
* Offsets for UART registers relative to SFR base address
* for UARTn
*
*/
#define ULCON 0x0000 /* Line Control */
#define UCON 0x0004 /* Control */
#define UFCON 0x0008 /* FIFO Control */
#define UMCON 0x000C /* Modem Control */
#define UTRSTAT 0x0010 /* Tx/Rx Status */
#define UERSTAT 0x0014 /* UART Error Status */
#define UFSTAT 0x0018 /* FIFO Status */
#define UMSTAT 0x001C /* Modem Status */
#define UTXH 0x0020 /* Transmit Buffer */
#define URXH 0x0024 /* Receive Buffer */
#define UBRDIV 0x0028 /* Baud Rate Divisor */
#define UFRACVAL 0x002C /* Divisor Fractional Value */
#define UINTP 0x0030 /* Interrupt Pending */
#define UINTSP 0x0034 /* Interrupt Source Pending */
#define UINTM 0x0038 /* Interrupt Mask */
/*
* for indexing register in the uint32_t array
*
* 'reg' - register offset (see offsets definitions above)
*
*/
#define I_(reg) (reg / sizeof(uint32_t))
typedef struct Exynos4210UartReg {
const char *name; /* the only reason is the debug output */
hwaddr offset;
uint32_t reset_value;
} Exynos4210UartReg;
static const Exynos4210UartReg exynos4210_uart_regs[] = {
{"ULCON", ULCON, 0x00000000},
{"UCON", UCON, 0x00003000},
{"UFCON", UFCON, 0x00000000},
{"UMCON", UMCON, 0x00000000},
{"UTRSTAT", UTRSTAT, 0x00000006}, /* RO */
{"UERSTAT", UERSTAT, 0x00000000}, /* RO */
{"UFSTAT", UFSTAT, 0x00000000}, /* RO */
{"UMSTAT", UMSTAT, 0x00000000}, /* RO */
{"UTXH", UTXH, 0x5c5c5c5c}, /* WO, undefined reset value*/
{"URXH", URXH, 0x00000000}, /* RO */
{"UBRDIV", UBRDIV, 0x00000000},
{"UFRACVAL", UFRACVAL, 0x00000000},
{"UINTP", UINTP, 0x00000000},
{"UINTSP", UINTSP, 0x00000000},
{"UINTM", UINTM, 0x00000000},
};
#define EXYNOS4210_UART_REGS_MEM_SIZE 0x3C
/* UART FIFO Control */
#define UFCON_FIFO_ENABLE 0x1
#define UFCON_Rx_FIFO_RESET 0x2
#define UFCON_Tx_FIFO_RESET 0x4
#define UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT 8
#define UFCON_Tx_FIFO_TRIGGER_LEVEL (7 << UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT)
#define UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT 4
#define UFCON_Rx_FIFO_TRIGGER_LEVEL (7 << UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT)
/* Uart FIFO Status */
#define UFSTAT_Rx_FIFO_COUNT 0xff
#define UFSTAT_Rx_FIFO_FULL 0x100
#define UFSTAT_Rx_FIFO_ERROR 0x200
#define UFSTAT_Tx_FIFO_COUNT_SHIFT 16
#define UFSTAT_Tx_FIFO_COUNT (0xff << UFSTAT_Tx_FIFO_COUNT_SHIFT)
#define UFSTAT_Tx_FIFO_FULL_SHIFT 24
#define UFSTAT_Tx_FIFO_FULL (1 << UFSTAT_Tx_FIFO_FULL_SHIFT)
/* UART Interrupt Source Pending */
#define UINTSP_RXD 0x1 /* Receive interrupt */
#define UINTSP_ERROR 0x2 /* Error interrupt */
#define UINTSP_TXD 0x4 /* Transmit interrupt */
#define UINTSP_MODEM 0x8 /* Modem interrupt */
/* UART Line Control */
#define ULCON_IR_MODE_SHIFT 6
#define ULCON_PARITY_SHIFT 3
#define ULCON_STOP_BIT_SHIFT 1
/* UART Tx/Rx Status */
#define UTRSTAT_TRANSMITTER_EMPTY 0x4
#define UTRSTAT_Tx_BUFFER_EMPTY 0x2
#define UTRSTAT_Rx_BUFFER_DATA_READY 0x1
/* UART Error Status */
#define UERSTAT_OVERRUN 0x1
#define UERSTAT_PARITY 0x2
#define UERSTAT_FRAME 0x4
#define UERSTAT_BREAK 0x8
typedef struct {
uint8_t *data;
uint32_t sp, rp; /* store and retrieve pointers */
uint32_t size;
} Exynos4210UartFIFO;
#define TYPE_EXYNOS4210_UART "exynos4210.uart"
#define EXYNOS4210_UART(obj) \
OBJECT_CHECK(Exynos4210UartState, (obj), TYPE_EXYNOS4210_UART)
typedef struct Exynos4210UartState {
SysBusDevice parent_obj;
MemoryRegion iomem;
uint32_t reg[EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)];
Exynos4210UartFIFO rx;
Exynos4210UartFIFO tx;
CharBackend chr;
qemu_irq irq;
uint32_t channel;
} Exynos4210UartState;
#if DEBUG_UART
/* Used only for debugging inside PRINT_DEBUG_... macros */
static const char *exynos4210_uart_regname(hwaddr offset)
{
int i;
for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) {
if (offset == exynos4210_uart_regs[i].offset) {
return exynos4210_uart_regs[i].name;
}
}
return NULL;
}
#endif
static void fifo_store(Exynos4210UartFIFO *q, uint8_t ch)
{
q->data[q->sp] = ch;
q->sp = (q->sp + 1) % q->size;
}
static uint8_t fifo_retrieve(Exynos4210UartFIFO *q)
{
uint8_t ret = q->data[q->rp];
q->rp = (q->rp + 1) % q->size;
return ret;
}
static int fifo_elements_number(const Exynos4210UartFIFO *q)
{
if (q->sp < q->rp) {
return q->size - q->rp + q->sp;
}
return q->sp - q->rp;
}
static int fifo_empty_elements_number(const Exynos4210UartFIFO *q)
{
return q->size - fifo_elements_number(q);
}
static void fifo_reset(Exynos4210UartFIFO *q)
{
g_free(q->data);
q->data = NULL;
q->data = (uint8_t *)g_malloc0(q->size);
q->sp = 0;
q->rp = 0;
}
static uint32_t exynos4210_uart_Tx_FIFO_trigger_level(const Exynos4210UartState *s)
{
uint32_t level = 0;
uint32_t reg;
reg = (s->reg[I_(UFCON)] & UFCON_Tx_FIFO_TRIGGER_LEVEL) >>
UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT;
switch (s->channel) {
case 0:
level = reg * 32;
break;
case 1:
case 4:
level = reg * 8;
break;
case 2:
case 3:
level = reg * 2;
break;
default:
level = 0;
PRINT_ERROR("Wrong UART channel number: %d\n", s->channel);
}
return level;
}
static void exynos4210_uart_update_irq(Exynos4210UartState *s)
{
/*
* The Tx interrupt is always requested if the number of data in the
* transmit FIFO is smaller than the trigger level.
*/
if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
uint32_t count = (s->reg[I_(UFSTAT)] & UFSTAT_Tx_FIFO_COUNT) >>
UFSTAT_Tx_FIFO_COUNT_SHIFT;
if (count <= exynos4210_uart_Tx_FIFO_trigger_level(s)) {
s->reg[I_(UINTSP)] |= UINTSP_TXD;
}
}
s->reg[I_(UINTP)] = s->reg[I_(UINTSP)] & ~s->reg[I_(UINTM)];
if (s->reg[I_(UINTP)]) {
qemu_irq_raise(s->irq);
#if DEBUG_IRQ
fprintf(stderr, "UART%d: IRQ has been raised: %08x\n",
s->channel, s->reg[I_(UINTP)]);
#endif
} else {
qemu_irq_lower(s->irq);
}
}
static void exynos4210_uart_update_parameters(Exynos4210UartState *s)
{
int speed, parity, data_bits, stop_bits;
QEMUSerialSetParams ssp;
uint64_t uclk_rate;
if (s->reg[I_(UBRDIV)] == 0) {
return;
}
if (s->reg[I_(ULCON)] & 0x20) {
if (s->reg[I_(ULCON)] & 0x28) {
parity = 'E';
} else {
parity = 'O';
}
} else {
parity = 'N';
}
if (s->reg[I_(ULCON)] & 0x4) {
stop_bits = 2;
} else {
stop_bits = 1;
}
data_bits = (s->reg[I_(ULCON)] & 0x3) + 5;
uclk_rate = 24000000;
speed = uclk_rate / ((16 * (s->reg[I_(UBRDIV)]) & 0xffff) +
(s->reg[I_(UFRACVAL)] & 0x7) + 16);
ssp.speed = speed;
ssp.parity = parity;
ssp.data_bits = data_bits;
ssp.stop_bits = stop_bits;
qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
PRINT_DEBUG("UART%d: speed: %d, parity: %c, data: %d, stop: %d\n",
s->channel, speed, parity, data_bits, stop_bits);
}
static void exynos4210_uart_write(void *opaque, hwaddr offset,
uint64_t val, unsigned size)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
uint8_t ch;
PRINT_DEBUG_EXTEND("UART%d: <0x%04x> %s <- 0x%08llx\n", s->channel,
offset, exynos4210_uart_regname(offset), (long long unsigned int)val);
switch (offset) {
case ULCON:
case UBRDIV:
case UFRACVAL:
s->reg[I_(offset)] = val;
exynos4210_uart_update_parameters(s);
break;
case UFCON:
s->reg[I_(UFCON)] = val;
if (val & UFCON_Rx_FIFO_RESET) {
fifo_reset(&s->rx);
s->reg[I_(UFCON)] &= ~UFCON_Rx_FIFO_RESET;
PRINT_DEBUG("UART%d: Rx FIFO Reset\n", s->channel);
}
if (val & UFCON_Tx_FIFO_RESET) {
fifo_reset(&s->tx);
s->reg[I_(UFCON)] &= ~UFCON_Tx_FIFO_RESET;
PRINT_DEBUG("UART%d: Tx FIFO Reset\n", s->channel);
}
break;
case UTXH:
if (qemu_chr_fe_backend_connected(&s->chr)) {
s->reg[I_(UTRSTAT)] &= ~(UTRSTAT_TRANSMITTER_EMPTY |
UTRSTAT_Tx_BUFFER_EMPTY);
ch = (uint8_t)val;
/* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks */
qemu_chr_fe_write_all(&s->chr, &ch, 1);
#if DEBUG_Tx_DATA
fprintf(stderr, "%c", ch);
#endif
s->reg[I_(UTRSTAT)] |= UTRSTAT_TRANSMITTER_EMPTY |
UTRSTAT_Tx_BUFFER_EMPTY;
s->reg[I_(UINTSP)] |= UINTSP_TXD;
exynos4210_uart_update_irq(s);
}
break;
case UINTP:
s->reg[I_(UINTP)] &= ~val;
s->reg[I_(UINTSP)] &= ~val;
PRINT_DEBUG("UART%d: UINTP [%04x] have been cleared: %08x\n",
s->channel, offset, s->reg[I_(UINTP)]);
exynos4210_uart_update_irq(s);
break;
case UTRSTAT:
case UERSTAT:
case UFSTAT:
case UMSTAT:
case URXH:
PRINT_DEBUG("UART%d: Trying to write into RO register: %s [%04x]\n",
s->channel, exynos4210_uart_regname(offset), offset);
break;
case UINTSP:
s->reg[I_(UINTSP)] &= ~val;
break;
case UINTM:
s->reg[I_(UINTM)] = val;
exynos4210_uart_update_irq(s);
break;
case UCON:
case UMCON:
default:
s->reg[I_(offset)] = val;
break;
}
}
static uint64_t exynos4210_uart_read(void *opaque, hwaddr offset,
unsigned size)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
uint32_t res;
switch (offset) {
case UERSTAT: /* Read Only */
res = s->reg[I_(UERSTAT)];
s->reg[I_(UERSTAT)] = 0;
return res;
case UFSTAT: /* Read Only */
s->reg[I_(UFSTAT)] = fifo_elements_number(&s->rx) & 0xff;
if (fifo_empty_elements_number(&s->rx) == 0) {
s->reg[I_(UFSTAT)] |= UFSTAT_Rx_FIFO_FULL;
s->reg[I_(UFSTAT)] &= ~0xff;
}
return s->reg[I_(UFSTAT)];
case URXH:
if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
if (fifo_elements_number(&s->rx)) {
res = fifo_retrieve(&s->rx);
#if DEBUG_Rx_DATA
fprintf(stderr, "%c", res);
#endif
if (!fifo_elements_number(&s->rx)) {
s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY;
} else {
s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
}
} else {
s->reg[I_(UINTSP)] |= UINTSP_ERROR;
exynos4210_uart_update_irq(s);
res = 0;
}
} else {
s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY;
res = s->reg[I_(URXH)];
}
return res;
case UTXH:
PRINT_DEBUG("UART%d: Trying to read from WO register: %s [%04x]\n",
s->channel, exynos4210_uart_regname(offset), offset);
break;
default:
return s->reg[I_(offset)];
}
return 0;
}
static const MemoryRegionOps exynos4210_uart_ops = {
.read = exynos4210_uart_read,
.write = exynos4210_uart_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.max_access_size = 4,
.unaligned = false
},
};
static int exynos4210_uart_can_receive(void *opaque)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
return fifo_empty_elements_number(&s->rx);
}
static void exynos4210_uart_receive(void *opaque, const uint8_t *buf, int size)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
int i;
if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
if (fifo_empty_elements_number(&s->rx) < size) {
for (i = 0; i < fifo_empty_elements_number(&s->rx); i++) {
fifo_store(&s->rx, buf[i]);
}
s->reg[I_(UINTSP)] |= UINTSP_ERROR;
s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
} else {
for (i = 0; i < size; i++) {
fifo_store(&s->rx, buf[i]);
}
s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
}
/* XXX: Around here we maybe should check Rx trigger level */
s->reg[I_(UINTSP)] |= UINTSP_RXD;
} else {
s->reg[I_(URXH)] = buf[0];
s->reg[I_(UINTSP)] |= UINTSP_RXD;
s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
}
exynos4210_uart_update_irq(s);
}
static void exynos4210_uart_event(void *opaque, int event)
{
Exynos4210UartState *s = (Exynos4210UartState *)opaque;
if (event == CHR_EVENT_BREAK) {
/* When the RxDn is held in logic 0, then a null byte is pushed into the
* fifo */
fifo_store(&s->rx, '\0');
s->reg[I_(UERSTAT)] |= UERSTAT_BREAK;
exynos4210_uart_update_irq(s);
}
}
static void exynos4210_uart_reset(DeviceState *dev)
{
Exynos4210UartState *s = EXYNOS4210_UART(dev);
int i;
for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) {
s->reg[I_(exynos4210_uart_regs[i].offset)] =
exynos4210_uart_regs[i].reset_value;
}
fifo_reset(&s->rx);
fifo_reset(&s->tx);
PRINT_DEBUG("UART%d: Rx FIFO size: %d\n", s->channel, s->rx.size);
}
static const VMStateDescription vmstate_exynos4210_uart_fifo = {
.name = "exynos4210.uart.fifo",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(sp, Exynos4210UartFIFO),
VMSTATE_UINT32(rp, Exynos4210UartFIFO),
VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, size),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_exynos4210_uart = {
.name = "exynos4210.uart",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_STRUCT(rx, Exynos4210UartState, 1,
vmstate_exynos4210_uart_fifo, Exynos4210UartFIFO),
VMSTATE_UINT32_ARRAY(reg, Exynos4210UartState,
EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)),
VMSTATE_END_OF_LIST()
}
};
DeviceState *exynos4210_uart_create(hwaddr addr,
int fifo_size,
int channel,
Chardev *chr,
qemu_irq irq)
{
DeviceState *dev;
SysBusDevice *bus;
dev = qdev_create(NULL, TYPE_EXYNOS4210_UART);
qdev_prop_set_chr(dev, "chardev", chr);
qdev_prop_set_uint32(dev, "channel", channel);
qdev_prop_set_uint32(dev, "rx-size", fifo_size);
qdev_prop_set_uint32(dev, "tx-size", fifo_size);
bus = SYS_BUS_DEVICE(dev);
qdev_init_nofail(dev);
if (addr != (hwaddr)-1) {
sysbus_mmio_map(bus, 0, addr);
}
sysbus_connect_irq(bus, 0, irq);
return dev;
}
static void exynos4210_uart_init(Object *obj)
{
SysBusDevice *dev = SYS_BUS_DEVICE(obj);
Exynos4210UartState *s = EXYNOS4210_UART(dev);
/* memory mapping */
memory_region_init_io(&s->iomem, obj, &exynos4210_uart_ops, s,
"exynos4210.uart", EXYNOS4210_UART_REGS_MEM_SIZE);
sysbus_init_mmio(dev, &s->iomem);
sysbus_init_irq(dev, &s->irq);
}
static void exynos4210_uart_realize(DeviceState *dev, Error **errp)
{
Exynos4210UartState *s = EXYNOS4210_UART(dev);
qemu_chr_fe_set_handlers(&s->chr, exynos4210_uart_can_receive,
exynos4210_uart_receive, exynos4210_uart_event,
NULL, s, NULL, true);
}
static Property exynos4210_uart_properties[] = {
DEFINE_PROP_CHR("chardev", Exynos4210UartState, chr),
DEFINE_PROP_UINT32("channel", Exynos4210UartState, channel, 0),
DEFINE_PROP_UINT32("rx-size", Exynos4210UartState, rx.size, 16),
DEFINE_PROP_UINT32("tx-size", Exynos4210UartState, tx.size, 16),
DEFINE_PROP_END_OF_LIST(),
};
static void exynos4210_uart_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = exynos4210_uart_realize;
dc->reset = exynos4210_uart_reset;
dc->props = exynos4210_uart_properties;
dc->vmsd = &vmstate_exynos4210_uart;
}
static const TypeInfo exynos4210_uart_info = {
.name = TYPE_EXYNOS4210_UART,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(Exynos4210UartState),
.instance_init = exynos4210_uart_init,
.class_init = exynos4210_uart_class_init,
};
static void exynos4210_uart_register(void)
{
type_register_static(&exynos4210_uart_info);
}
type_init(exynos4210_uart_register)
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