/*
* STM32F2XX USART
*
* Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
*
* 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 "qemu/osdep.h"
#include "hw/char/stm32f2xx_usart.h"
#include "qemu/log.h"
#ifndef STM_USART_ERR_DEBUG
#define STM_USART_ERR_DEBUG 0
#endif
#define DB_PRINT_L(lvl, fmt, args...) do { \
if (STM_USART_ERR_DEBUG >= lvl) { \
qemu_log("%s: " fmt, __func__, ## args); \
} \
} while (0);
#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
static int stm32f2xx_usart_can_receive(void *opaque)
{
STM32F2XXUsartState *s = opaque;
if (!(s->usart_sr & USART_SR_RXNE)) {
return 1;
}
return 0;
}
static void stm32f2xx_usart_receive(void *opaque, const uint8_t *buf, int size)
{
STM32F2XXUsartState *s = opaque;
s->usart_dr = *buf;
if (!(s->usart_cr1 & USART_CR1_UE && s->usart_cr1 & USART_CR1_RE)) {
/* USART not enabled - drop the chars */
DB_PRINT("Dropping the chars\n");
return;
}
s->usart_sr |= USART_SR_RXNE;
if (s->usart_cr1 & USART_CR1_RXNEIE) {
qemu_set_irq(s->irq, 1);
}
DB_PRINT("Receiving: %c\n", s->usart_dr);
}
static void stm32f2xx_usart_reset(DeviceState *dev)
{
STM32F2XXUsartState *s = STM32F2XX_USART(dev);
s->usart_sr = USART_SR_RESET;
s->usart_dr = 0x00000000;
s->usart_brr = 0x00000000;
s->usart_cr1 = 0x00000000;
s->usart_cr2 = 0x00000000;
s->usart_cr3 = 0x00000000;
s->usart_gtpr = 0x00000000;
qemu_set_irq(s->irq, 0);
}
static uint64_t stm32f2xx_usart_read(void *opaque, hwaddr addr,
unsigned int size)
{
STM32F2XXUsartState *s = opaque;
uint64_t retvalue;
DB_PRINT("Read 0x%"HWADDR_PRIx"\n", addr);
switch (addr) {
case USART_SR:
retvalue = s->usart_sr;
s->usart_sr &= ~USART_SR_TC;
qemu_chr_fe_accept_input(&s->chr);
return retvalue;
case USART_DR:
DB_PRINT("Value: 0x%" PRIx32 ", %c\n", s->usart_dr, (char) s->usart_dr);
s->usart_sr |= USART_SR_TXE;
s->usart_sr &= ~USART_SR_RXNE;
qemu_chr_fe_accept_input(&s->chr);
qemu_set_irq(s->irq, 0);
return s->usart_dr & 0x3FF;
case USART_BRR:
return s->usart_brr;
case USART_CR1:
return s->usart_cr1;
case USART_CR2:
return s->usart_cr2;
case USART_CR3:
return s->usart_cr3;
case USART_GTPR:
return s->usart_gtpr;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
return 0;
}
return 0;
}
static void stm32f2xx_usart_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
STM32F2XXUsartState *s = opaque;
uint32_t value = val64;
unsigned char ch;
DB_PRINT("Write 0x%" PRIx32 ", 0x%"HWADDR_PRIx"\n", value, addr);
switch (addr) {
case USART_SR:
if (value <= 0x3FF) {
s->usart_sr = value;
} else {
s->usart_sr &= value;
}
if (!(s->usart_sr & USART_SR_RXNE)) {
qemu_set_irq(s->irq, 0);
}
return;
case USART_DR:
if (value < 0xF000) {
ch = value;
/* 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);
s->usart_sr |= USART_SR_TC;
s->usart_sr &= ~USART_SR_TXE;
}
return;
case USART_BRR:
s->usart_brr = value;
return;
case USART_CR1:
s->usart_cr1 = value;
if (s->usart_cr1 & USART_CR1_RXNEIE &&
s->usart_sr & USART_SR_RXNE) {
qemu_set_irq(s->irq, 1);
}
return;
case USART_CR2:
s->usart_cr2 = value;
return;
case USART_CR3:
s->usart_cr3 = value;
return;
case USART_GTPR:
s->usart_gtpr = value;
return;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
}
}
static const MemoryRegionOps stm32f2xx_usart_ops = {
.read = stm32f2xx_usart_read,
.write = stm32f2xx_usart_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static Property stm32f2xx_usart_properties[] = {
DEFINE_PROP_CHR("chardev", STM32F2XXUsartState, chr),
DEFINE_PROP_END_OF_LIST(),
};
static void stm32f2xx_usart_init(Object *obj)
{
STM32F2XXUsartState *s = STM32F2XX_USART(obj);
sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
memory_region_init_io(&s->mmio, obj, &stm32f2xx_usart_ops, s,
TYPE_STM32F2XX_USART, 0x2000);
sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
}
static void stm32f2xx_usart_realize(DeviceState *dev, Error **errp)
{
STM32F2XXUsartState *s = STM32F2XX_USART(dev);
qemu_chr_fe_set_handlers(&s->chr, stm32f2xx_usart_can_receive,
stm32f2xx_usart_receive, NULL, NULL,
s, NULL, true);
}
static void stm32f2xx_usart_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->reset = stm32f2xx_usart_reset;
dc->props = stm32f2xx_usart_properties;
dc->realize = stm32f2xx_usart_realize;
}
static const TypeInfo stm32f2xx_usart_info = {
.name = TYPE_STM32F2XX_USART,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(STM32F2XXUsartState),
.instance_init = stm32f2xx_usart_init,
.class_init = stm32f2xx_usart_class_init,
};
static void stm32f2xx_usart_register_types(void)
{
type_register_static(&stm32f2xx_usart_info);
}
type_init(stm32f2xx_usart_register_types)
