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-rw-r--r--src/hw/char/stm32f2xx_usart.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/src/hw/char/stm32f2xx_usart.c b/src/hw/char/stm32f2xx_usart.c
new file mode 100644
index 0000000..c9d3a1b
--- /dev/null
+++ b/src/hw/char/stm32f2xx_usart.c
@@ -0,0 +1,232 @@
+/*
+ * 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);
+
+ /* FIXME use a qdev chardev prop instead of qemu_char_get_next_serial() */
+ 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;
+ /* Reason: instance_init() method uses qemu_char_get_next_serial() */
+ dc->cannot_instantiate_with_device_add_yet = true;
+}
+
+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)
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