xref: /openbmc/qemu/include/hw/char/sifive_uart.h (revision ffe98631)
1 /*
2  * SiFive UART interface
3  *
4  * Copyright (c) 2016 Stefan O'Rear
5  * Copyright (c) 2017 SiFive, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #ifndef HW_SIFIVE_UART_H
21 #define HW_SIFIVE_UART_H
22 
23 #include "chardev/char-fe.h"
24 #include "hw/qdev-properties.h"
25 #include "hw/sysbus.h"
26 #include "qom/object.h"
27 
28 enum {
29     SIFIVE_UART_TXFIFO        = 0,
30     SIFIVE_UART_RXFIFO        = 4,
31     SIFIVE_UART_TXCTRL        = 8,
32     SIFIVE_UART_TXMARK        = 10,
33     SIFIVE_UART_RXCTRL        = 12,
34     SIFIVE_UART_RXMARK        = 14,
35     SIFIVE_UART_IE            = 16,
36     SIFIVE_UART_IP            = 20,
37     SIFIVE_UART_DIV           = 24,
38     SIFIVE_UART_MAX           = 32
39 };
40 
41 enum {
42     SIFIVE_UART_IE_TXWM       = 1, /* Transmit watermark interrupt enable */
43     SIFIVE_UART_IE_RXWM       = 2  /* Receive watermark interrupt enable */
44 };
45 
46 enum {
47     SIFIVE_UART_IP_TXWM       = 1, /* Transmit watermark interrupt pending */
48     SIFIVE_UART_IP_RXWM       = 2  /* Receive watermark interrupt pending */
49 };
50 
51 #define SIFIVE_UART_GET_TXCNT(txctrl)   ((txctrl >> 16) & 0x7)
52 #define SIFIVE_UART_GET_RXCNT(rxctrl)   ((rxctrl >> 16) & 0x7)
53 #define SIFIVE_UART_RX_FIFO_SIZE 8
54 
55 #define TYPE_SIFIVE_UART "riscv.sifive.uart"
56 OBJECT_DECLARE_SIMPLE_TYPE(SiFiveUARTState, SIFIVE_UART)
57 
58 struct SiFiveUARTState {
59     /*< private >*/
60     SysBusDevice parent_obj;
61 
62     /*< public >*/
63     qemu_irq irq;
64     MemoryRegion mmio;
65     CharBackend chr;
66     uint8_t rx_fifo[SIFIVE_UART_RX_FIFO_SIZE];
67     uint8_t rx_fifo_len;
68     uint32_t ie;
69     uint32_t ip;
70     uint32_t txctrl;
71     uint32_t rxctrl;
72     uint32_t div;
73 };
74 
75 SiFiveUARTState *sifive_uart_create(MemoryRegion *address_space, hwaddr base,
76     Chardev *chr, qemu_irq irq);
77 
78 #endif
79