hw/char: Add Shakti UART emulation

This is the initial implementation of Shakti UART.

Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210401181457.73039-4-vijai@behindbytes.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/include/hw/char/shakti_uart.h b/include/hw/char/shakti_uart.h
new file mode 100644
index 0000000..526c408
--- /dev/null
+++ b/include/hw/char/shakti_uart.h
@@ -0,0 +1,74 @@
+/*
+ * SHAKTI UART
+ *
+ * Copyright (c) 2021 Vijai Kumar K <vijai@behindbytes.com>
+ *
+ * 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_SHAKTI_UART_H
+#define HW_SHAKTI_UART_H
+
+#include "hw/sysbus.h"
+#include "chardev/char-fe.h"
+
+#define SHAKTI_UART_BAUD        0x00
+#define SHAKTI_UART_TX          0x04
+#define SHAKTI_UART_RX          0x08
+#define SHAKTI_UART_STATUS      0x0C
+#define SHAKTI_UART_DELAY       0x10
+#define SHAKTI_UART_CONTROL     0x14
+#define SHAKTI_UART_INT_EN      0x18
+#define SHAKTI_UART_IQ_CYCLES   0x1C
+#define SHAKTI_UART_RX_THRES    0x20
+
+#define SHAKTI_UART_STATUS_TX_EMPTY     (1 << 0)
+#define SHAKTI_UART_STATUS_TX_FULL      (1 << 1)
+#define SHAKTI_UART_STATUS_RX_NOT_EMPTY (1 << 2)
+#define SHAKTI_UART_STATUS_RX_FULL      (1 << 3)
+/* 9600 8N1 is the default setting */
+/* Reg value = (50000000 Hz)/(16 * 9600)*/
+#define SHAKTI_UART_BAUD_DEFAULT    0x0145
+#define SHAKTI_UART_CONTROL_DEFAULT 0x0100
+
+#define TYPE_SHAKTI_UART "shakti-uart"
+#define SHAKTI_UART(obj) \
+    OBJECT_CHECK(ShaktiUartState, (obj), TYPE_SHAKTI_UART)
+
+typedef struct {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    /* <public> */
+    MemoryRegion mmio;
+
+    uint32_t uart_baud;
+    uint32_t uart_tx;
+    uint32_t uart_rx;
+    uint32_t uart_status;
+    uint32_t uart_delay;
+    uint32_t uart_control;
+    uint32_t uart_interrupt;
+    uint32_t uart_iq_cycles;
+    uint32_t uart_rx_threshold;
+
+    CharBackend chr;
+} ShaktiUartState;
+
+#endif /* HW_SHAKTI_UART_H */