+static void ibex_uart_write(void *opaque, hwaddr addr,
+ uint64_t val64, unsigned int size)
+{
+ IbexUartState *s = opaque;
+ uint32_t value = val64;
+
+ switch (addr) {
+ case IBEX_UART_INTR_STATE:
+ /* Write 1 clear */
+ s->uart_intr_state &= ~value;
+ ibex_uart_update_irqs(s);
+ break;
+ case IBEX_UART_INTR_ENABLE:
+ s->uart_intr_enable = value;
+ ibex_uart_update_irqs(s);
+ break;
+ case IBEX_UART_INTR_TEST:
+ s->uart_intr_state |= value;
+ ibex_uart_update_irqs(s);
+ break;
+
+ case IBEX_UART_CTRL:
+ s->uart_ctrl = value;
+
+ if (value & UART_CTRL_NF) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_NF is not supported\n", __func__);
+ }
+ if (value & UART_CTRL_SLPBK) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_SLPBK is not supported\n", __func__);
+ }
+ if (value & UART_CTRL_LLPBK) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_LLPBK is not supported\n", __func__);
+ }
+ if (value & UART_CTRL_PARITY_EN) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_PARITY_EN is not supported\n",
+ __func__);
+ }
+ if (value & UART_CTRL_PARITY_ODD) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_PARITY_ODD is not supported\n",
+ __func__);
+ }
+ if (value & UART_CTRL_RXBLVL) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: UART_CTRL_RXBLVL is not supported\n", __func__);
+ }
+ if (value & UART_CTRL_NCO) {
+ uint64_t baud = ((value & UART_CTRL_NCO) >> 16);
+ baud *= 1000;
+ baud /= 2 ^ 20;
+
+ s->char_tx_time = (NANOSECONDS_PER_SECOND / baud) * 10;
+ }
+ break;
+ case IBEX_UART_STATUS:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: status is read only\n", __func__);
+ break;
+
+ case IBEX_UART_RDATA:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: rdata is read only\n", __func__);
+ break;
+ case IBEX_UART_WDATA:
+ uart_write_tx_fifo(s, (uint8_t *) &value, 1);
+ break;
+
+ case IBEX_UART_FIFO_CTRL:
+ s->uart_fifo_ctrl = value;
+
+ if (value & FIFO_CTRL_RXRST) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: RX fifos are not supported\n", __func__);
+ }
+ if (value & FIFO_CTRL_TXRST) {
+ s->tx_level = 0;
+ }
+ break;
+ case IBEX_UART_FIFO_STATUS:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: fifo_status is read only\n", __func__);
+ break;
+
+ case IBEX_UART_OVRD:
+ s->uart_ovrd = value;
+ qemu_log_mask(LOG_UNIMP,
+ "%s: ovrd is not supported\n", __func__);
+ break;
+ case IBEX_UART_VAL:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: val is read only\n", __func__);
+ break;
+ case IBEX_UART_TIMEOUT_CTRL:
+ s->uart_timeout_ctrl = value;
+ qemu_log_mask(LOG_UNIMP,
+ "%s: timeout_ctrl is not supported\n", __func__);
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
+ }
+}
+
+static void fifo_trigger_update(void *opaque)
+{
+ IbexUartState *s = opaque;
+
+ if (s->uart_ctrl & UART_CTRL_TX_ENABLE) {
+ ibex_uart_xmit(NULL, G_IO_OUT, s);
+ }
+}
+
+static const MemoryRegionOps ibex_uart_ops = {
+ .read = ibex_uart_read,
+ .write = ibex_uart_write,
diff --git a/include/hw/char/ibex_uart.h b/include/hw/char/ibex_uart.h
new file mode 100644
index 0000000000..2bec772615
--- /dev/null
+++ b/include/hw/char/ibex_uart.h
@@ -0,0 +1,110 @@
+/*
+ * QEMU lowRISC Ibex UART device
+ *
+ * Copyright (c) 2020 Western Digital
+ *
+ * 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.
+ */
+
+#ifndef HW_IBEX_UART_H
+#define HW_IBEX_UART_H
+
+#include "hw/sysbus.h"
+#include "chardev/char-fe.h"
+#include "qemu/timer.h"
+
+#define IBEX_UART_INTR_STATE 0x00
+ #define INTR_STATE_TX_WATERMARK (1 << 0)
+ #define INTR_STATE_RX_WATERMARK (1 << 1)
+ #define INTR_STATE_TX_EMPTY (1 << 2)
+ #define INTR_STATE_RX_OVERFLOW (1 << 3)
+#define IBEX_UART_INTR_ENABLE 0x04
+#define IBEX_UART_INTR_TEST 0x08
+
+#define IBEX_UART_CTRL 0x0c
+ #define UART_CTRL_TX_ENABLE (1 << 0)
+ #define UART_CTRL_RX_ENABLE (1 << 1)
+ #define UART_CTRL_NF (1 << 2)
+ #define UART_CTRL_SLPBK (1 << 4)
+ #define UART_CTRL_LLPBK (1 << 5)
+ #define UART_CTRL_PARITY_EN (1 << 6)
+ #define UART_CTRL_PARITY_ODD (1 << 7)
+ #define UART_CTRL_RXBLVL (3 << 8)
+ #define UART_CTRL_NCO (0xFFFF << 16)
+
+#define IBEX_UART_STATUS 0x10
+ #define UART_STATUS_TXFULL (1 << 0)
+ #define UART_STATUS_RXFULL (1 << 1)
+ #define UART_STATUS_TXEMPTY (1 << 2)
+ #define UART_STATUS_RXIDLE (1 << 4)
+ #define UART_STATUS_RXEMPTY (1 << 5)
+
+#define IBEX_UART_RDATA 0x14
+#define IBEX_UART_WDATA 0x18
+
+#define IBEX_UART_FIFO_CTRL 0x1c
+ #define FIFO_CTRL_RXRST (1 << 0)
+ #define FIFO_CTRL_TXRST (1 << 1)
+ #define FIFO_CTRL_RXILVL (7 << 2)
+ #define FIFO_CTRL_RXILVL_SHIFT (2)
+ #define FIFO_CTRL_TXILVL (3 << 5)
+ #define FIFO_CTRL_TXILVL_SHIFT (5)
+
+#define IBEX_UART_FIFO_STATUS 0x20
+#define IBEX_UART_OVRD 0x24
+#define IBEX_UART_VAL 0x28
+#define IBEX_UART_TIMEOUT_CTRL 0x2c
+
+#define IBEX_UART_TX_FIFO_SIZE 16
+
+#define TYPE_IBEX_UART "ibex-uart"
+#define IBEX_UART(obj) \
+ OBJECT_CHECK(IbexUartState, (obj), TYPE_IBEX_UART)
+
+typedef struct {
+ /* <private> */
+ SysBusDevice parent_obj;
+
+ /* <public> */
+ MemoryRegion mmio;
+
+ uint8_t tx_fifo[IBEX_UART_TX_FIFO_SIZE];
+ uint32_t tx_level;
+
+ QEMUTimer *fifo_trigger_handle;
+ uint64_t char_tx_time;
+
+ uint32_t uart_intr_state;
+ uint32_t uart_intr_enable;
+ uint32_t uart_ctrl;
+ uint32_t uart_status;
+ uint32_t uart_rdata;
+ uint32_t uart_fifo_ctrl;
+ uint32_t uart_fifo_status;
+ uint32_t uart_ovrd;
+ uint32_t uart_val;
+ uint32_t uart_timeout_ctrl;
+
+ CharBackend chr;
+ qemu_irq tx_watermark;
+ qemu_irq rx_watermark;
+ qemu_irq tx_empty;
+ qemu_irq rx_overflow;
+} IbexUartState;
+#endif /* HW_IBEX_UART_H */