xref: /openbmc/qemu/include/hw/char/ibex_uart.h (revision a81df1b6)
1 /*
2  * QEMU lowRISC Ibex UART device
3  *
4  * Copyright (c) 2020 Western Digital
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #ifndef HW_IBEX_UART_H
26 #define HW_IBEX_UART_H
27 
28 #include "hw/sysbus.h"
29 #include "hw/registerfields.h"
30 #include "chardev/char-fe.h"
31 #include "qemu/timer.h"
32 
33 REG32(INTR_STATE, 0x00)
34     FIELD(INTR_STATE, TX_WATERMARK, 0, 1)
35     FIELD(INTR_STATE, RX_WATERMARK, 1, 1)
36     FIELD(INTR_STATE, TX_EMPTY, 2, 1)
37     FIELD(INTR_STATE, RX_OVERFLOW, 3, 1)
38 REG32(INTR_ENABLE, 0x04)
39 REG32(INTR_TEST, 0x08)
40 REG32(CTRL, 0x0C)
41     FIELD(CTRL, TX_ENABLE, 0, 1)
42     FIELD(CTRL, RX_ENABLE, 1, 1)
43     FIELD(CTRL, NF, 2, 1)
44     FIELD(CTRL, SLPBK, 4, 1)
45     FIELD(CTRL, LLPBK, 5, 1)
46     FIELD(CTRL, PARITY_EN, 6, 1)
47     FIELD(CTRL, PARITY_ODD, 7, 1)
48     FIELD(CTRL, RXBLVL, 8, 2)
49     FIELD(CTRL, NCO, 16, 16)
50 REG32(STATUS, 0x10)
51     FIELD(STATUS, TXFULL, 0, 1)
52     FIELD(STATUS, RXFULL, 1, 1)
53     FIELD(STATUS, TXEMPTY, 2, 1)
54     FIELD(STATUS, RXIDLE, 4, 1)
55     FIELD(STATUS, RXEMPTY, 5, 1)
56 REG32(RDATA, 0x14)
57 REG32(WDATA, 0x18)
58 REG32(FIFO_CTRL, 0x1c)
59     FIELD(FIFO_CTRL, RXRST, 0, 1)
60     FIELD(FIFO_CTRL, TXRST, 1, 1)
61     FIELD(FIFO_CTRL, RXILVL, 2, 3)
62     FIELD(FIFO_CTRL, TXILVL, 5, 2)
63 REG32(FIFO_STATUS, 0x20)
64 REG32(OVRD, 0x24)
65 REG32(VAL, 0x28)
66 REG32(TIMEOUT_CTRL, 0x2c)
67 
68 #define IBEX_UART_TX_FIFO_SIZE 16
69 #define IBEX_UART_CLOCK 50000000 /* 50MHz clock */
70 
71 #define TYPE_IBEX_UART "ibex-uart"
72 #define IBEX_UART(obj) \
73     OBJECT_CHECK(IbexUartState, (obj), TYPE_IBEX_UART)
74 
75 typedef struct {
76     /* <private> */
77     SysBusDevice parent_obj;
78 
79     /* <public> */
80     MemoryRegion mmio;
81 
82     uint8_t tx_fifo[IBEX_UART_TX_FIFO_SIZE];
83     uint32_t tx_level;
84 
85     QEMUTimer *fifo_trigger_handle;
86     uint64_t char_tx_time;
87 
88     uint32_t uart_intr_state;
89     uint32_t uart_intr_enable;
90     uint32_t uart_ctrl;
91     uint32_t uart_status;
92     uint32_t uart_rdata;
93     uint32_t uart_fifo_ctrl;
94     uint32_t uart_fifo_status;
95     uint32_t uart_ovrd;
96     uint32_t uart_val;
97     uint32_t uart_timeout_ctrl;
98 
99     Clock *f_clk;
100 
101     CharBackend chr;
102     qemu_irq tx_watermark;
103     qemu_irq rx_watermark;
104     qemu_irq tx_empty;
105     qemu_irq rx_overflow;
106 } IbexUartState;
107 #endif /* HW_IBEX_UART_H */
108