xref: /openbmc/qemu/include/hw/char/serial.h (revision d6032e06)
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 #ifndef HW_SERIAL_H
26 #define HW_SERIAL_H 1
27 
28 #include "hw/hw.h"
29 #include "sysemu/sysemu.h"
30 #include "exec/memory.h"
31 #include "qemu/fifo8.h"
32 
33 #define UART_FIFO_LENGTH    16      /* 16550A Fifo Length */
34 
35 struct SerialState {
36     uint16_t divider;
37     uint8_t rbr; /* receive register */
38     uint8_t thr; /* transmit holding register */
39     uint8_t tsr; /* transmit shift register */
40     uint8_t ier;
41     uint8_t iir; /* read only */
42     uint8_t lcr;
43     uint8_t mcr;
44     uint8_t lsr; /* read only */
45     uint8_t msr; /* read only */
46     uint8_t scr;
47     uint8_t fcr;
48     uint8_t fcr_vmstate; /* we can't write directly this value
49                             it has side effects */
50     /* NOTE: this hidden state is necessary for tx irq generation as
51        it can be reset while reading iir */
52     int thr_ipending;
53     qemu_irq irq;
54     CharDriverState *chr;
55     int last_break_enable;
56     int it_shift;
57     int baudbase;
58     int tsr_retry;
59     uint32_t wakeup;
60 
61     /* Time when the last byte was successfully sent out of the tsr */
62     uint64_t last_xmit_ts;
63     Fifo8 recv_fifo;
64     Fifo8 xmit_fifo;
65     /* Interrupt trigger level for recv_fifo */
66     uint8_t recv_fifo_itl;
67 
68     QEMUTimer *fifo_timeout_timer;
69     int timeout_ipending;           /* timeout interrupt pending state */
70 
71     uint64_t char_transmit_time;    /* time to transmit a char in ticks */
72     int poll_msl;
73 
74     QEMUTimer *modem_status_poll;
75     MemoryRegion io;
76 };
77 
78 extern const VMStateDescription vmstate_serial;
79 extern const MemoryRegionOps serial_io_ops;
80 
81 void serial_realize_core(SerialState *s, Error **errp);
82 void serial_exit_core(SerialState *s);
83 void serial_set_frequency(SerialState *s, uint32_t frequency);
84 
85 /* legacy pre qom */
86 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
87                          CharDriverState *chr, MemoryRegion *system_io);
88 SerialState *serial_mm_init(MemoryRegion *address_space,
89                             hwaddr base, int it_shift,
90                             qemu_irq irq, int baudbase,
91                             CharDriverState *chr, enum device_endian end);
92 
93 /* serial-isa.c */
94 #define TYPE_ISA_SERIAL "isa-serial"
95 bool serial_isa_init(ISABus *bus, int index, CharDriverState *chr);
96 
97 #endif
98