xref: /qemu/include/hw/char/serial.h (revision 33956e476802a6ae9b9a8e047f6a78e09e9ae180)
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  #include "qom/object.h"
35  
36  #define UART_FIFO_LENGTH    16      /* 16550A Fifo Length */
37  
38  struct SerialState {
39      DeviceState parent;
40  
41      uint16_t divider;
42      uint8_t rbr; /* receive register */
43      uint8_t thr; /* transmit holding register */
44      uint8_t tsr; /* transmit shift register */
45      uint8_t ier;
46      uint8_t iir; /* read only */
47      uint8_t lcr;
48      uint8_t mcr;
49      uint8_t lsr; /* read only */
50      uint8_t msr; /* read only */
51      uint8_t scr;
52      uint8_t fcr;
53      uint8_t fcr_vmstate; /* we can't write directly this value
54                              it has side effects */
55      /* NOTE: this hidden state is necessary for tx irq generation as
56         it can be reset while reading iir */
57      int thr_ipending;
58      qemu_irq irq;
59      CharBackend chr;
60      int last_break_enable;
61      uint32_t baudbase;
62      uint32_t tsr_retry;
63      guint watch_tag;
64      bool 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  };
82  typedef struct SerialState SerialState;
83  
84  struct SerialMM {
85      SysBusDevice parent;
86  
87      SerialState serial;
88  
89      uint8_t regshift;
90      uint8_t endianness;
91  };
92  
93  extern const VMStateDescription vmstate_serial;
94  extern const MemoryRegionOps serial_io_ops;
95  
96  void serial_set_frequency(SerialState *s, uint32_t frequency);
97  
98  #define TYPE_SERIAL "serial"
99  OBJECT_DECLARE_SIMPLE_TYPE(SerialState, SERIAL)
100  
101  #define TYPE_SERIAL_MM "serial-mm"
102  OBJECT_DECLARE_SIMPLE_TYPE(SerialMM, SERIAL_MM)
103  
104  SerialMM *serial_mm_init(MemoryRegion *address_space,
105                           hwaddr base, int regshift,
106                           qemu_irq irq, int baudbase,
107                           Chardev *chr, enum device_endian end);
108  
109  /* serial-isa.c */
110  
111  #define MAX_ISA_SERIAL_PORTS 4
112  
113  #define TYPE_ISA_SERIAL "isa-serial"
114  void serial_hds_isa_init(ISABus *bus, int from, int to);
115  void isa_serial_set_iobase(ISADevice *serial, hwaddr iobase);
116  void isa_serial_set_enabled(ISADevice *serial, bool enabled);
117  
118  #endif
119