diff options
Diffstat (limited to 'hw/char/stm32f2xx_usart.c')
| -rw-r--r-- | hw/char/stm32f2xx_usart.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/hw/char/stm32f2xx_usart.c b/hw/char/stm32f2xx_usart.c new file mode 100644 index 0000000000..260b053044 --- /dev/null +++ b/hw/char/stm32f2xx_usart.c @@ -0,0 +1,229 @@ +/* + * 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 "hw/char/stm32f2xx_usart.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; + if (s->chr) { + qemu_chr_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; + if (s->chr) { + qemu_chr_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; + if (s->chr) { + 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 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); + + s->chr = qemu_char_get_next_serial(); + + if (s->chr) { + qemu_chr_add_handlers(s->chr, stm32f2xx_usart_can_receive, + stm32f2xx_usart_receive, NULL, s); + } +} + +static void stm32f2xx_usart_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->reset = stm32f2xx_usart_reset; +} + +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) |