xref: /openbmc/qemu/include/hw/char/serial.h (revision 96651db4)
1 /*
2  * QEMU 16550A UART emulation
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  * Copyright (c) 2008 Citrix Systems, Inc.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #ifndef HW_SERIAL_H
27 #define HW_SERIAL_H
28 
29 #include "chardev/char-fe.h"
30 #include "exec/memory.h"
31 #include "qemu/fifo8.h"
32 #include "chardev/char.h"
33 #include "hw/sysbus.h"
34 
35 #define UART_FIFO_LENGTH    16      /* 16550A Fifo Length */
36 
37 typedef struct SerialState {
38     DeviceState parent;
39 
40     uint16_t divider;
41     uint8_t rbr; /* receive register */
42     uint8_t thr; /* transmit holding register */
43     uint8_t tsr; /* transmit shift register */
44     uint8_t ier;
45     uint8_t iir; /* read only */
46     uint8_t lcr;
47     uint8_t mcr;
48     uint8_t lsr; /* read only */
49     uint8_t msr; /* read only */
50     uint8_t scr;
51     uint8_t fcr;
52     uint8_t fcr_vmstate; /* we can't write directly this value
53                             it has side effects */
54     /* NOTE: this hidden state is necessary for tx irq generation as
55        it can be reset while reading iir */
56     int thr_ipending;
57     qemu_irq irq;
58     CharBackend chr;
59     int last_break_enable;
60     int it_shift;
61     uint32_t baudbase;
62     uint32_t tsr_retry;
63     guint watch_tag;
64     uint32_t wakeup;
65 
66     /* Time when the last byte was successfully sent out of the tsr */
67     uint64_t last_xmit_ts;
68     Fifo8 recv_fifo;
69     Fifo8 xmit_fifo;
70     /* Interrupt trigger level for recv_fifo */
71     uint8_t recv_fifo_itl;
72 
73     QEMUTimer *fifo_timeout_timer;
74     int timeout_ipending;           /* timeout interrupt pending state */
75 
76     uint64_t char_transmit_time;    /* time to transmit a char in ticks */
77     int poll_msl;
78 
79     QEMUTimer *modem_status_poll;
80     MemoryRegion io;
81 } SerialState;
82 
83 extern const VMStateDescription vmstate_serial;
84 extern const MemoryRegionOps serial_io_ops;
85 
86 void serial_realize_core(SerialState *s, Error **errp);
87 void serial_exit_core(SerialState *s);
88 void serial_set_frequency(SerialState *s, uint32_t frequency);
89 
90 #define TYPE_SERIAL "serial"
91 #define SERIAL(s) OBJECT_CHECK(SerialState, (s), TYPE_SERIAL)
92 
93 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
94                          Chardev *chr, MemoryRegion *system_io);
95 SerialState *serial_mm_init(MemoryRegion *address_space,
96                             hwaddr base, int it_shift,
97                             qemu_irq irq, int baudbase,
98                             Chardev *chr, enum device_endian end);
99 
100 /* serial-isa.c */
101 
102 #define MAX_ISA_SERIAL_PORTS 4
103 
104 #define TYPE_ISA_SERIAL "isa-serial"
105 void serial_hds_isa_init(ISABus *bus, int from, int to);
106 
107 #endif
108