xref: /freebsd/sys/dev/uart/uart.h (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2003 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #ifndef _DEV_UART_H_
32 #define _DEV_UART_H_
33 
34 /*
35  * Bus access structure. This structure holds the minimum information needed
36  * to access the UART. The rclk field, although not important to actually
37  * access the UART, is important for baudrate programming, delay loops and
38  * other timing related computations.
39  */
40 struct uart_bas {
41 	bus_space_tag_t bst;
42 	bus_space_handle_t bsh;
43 	u_int	chan;
44 	u_int	rclk;
45 	u_int	regshft;
46 	u_int	regiowidth;
47 	u_int	busy_detect;
48 };
49 
50 #define	uart_regofs(bas, reg)		((reg) << (bas)->regshft)
51 #define	uart_regiowidth(bas)		((bas)->regiowidth)
52 
53 static inline uint32_t
54 uart_getreg(struct uart_bas *bas, int reg)
55 {
56 	uint32_t ret;
57 
58 	switch (uart_regiowidth(bas)) {
59 	case 4:
60 		ret = bus_space_read_4(bas->bst, bas->bsh, uart_regofs(bas, reg));
61 		break;
62 	case 2:
63 		ret = bus_space_read_2(bas->bst, bas->bsh, uart_regofs(bas, reg));
64 		break;
65 	default:
66 		ret = bus_space_read_1(bas->bst, bas->bsh, uart_regofs(bas, reg));
67 		break;
68 	}
69 
70 	return (ret);
71 }
72 
73 static inline void
74 uart_setreg(struct uart_bas *bas, int reg, int value)
75 {
76 
77 	switch (uart_regiowidth(bas)) {
78 	case 4:
79 		bus_space_write_4(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
80 		break;
81 	case 2:
82 		bus_space_write_2(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
83 		break;
84 	default:
85 		bus_space_write_1(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
86 		break;
87 	}
88 }
89 
90 /*
91  * XXX we don't know the length of the bus space address range in use by
92  * the UART. Since barriers don't use the length field currently, we put
93  * a zero there for now.
94  */
95 #define uart_barrier(bas)		\
96 	bus_space_barrier((bas)->bst, (bas)->bsh, 0, 0,		\
97 	    BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE)
98 
99 /*
100  * UART device classes.
101  */
102 struct uart_class;
103 
104 extern struct uart_class uart_ns8250_class __attribute__((weak));
105 extern struct uart_class uart_quicc_class __attribute__((weak));
106 extern struct uart_class uart_z8530_class __attribute__((weak));
107 
108 /*
109  * Device flags.
110  */
111 #define	UART_FLAGS_CONSOLE(f)		((f) & 0x10)
112 #define	UART_FLAGS_DBGPORT(f)		((f) & 0x80)
113 #define	UART_FLAGS_FCR_RX_LOW(f)	((f) & 0x100)
114 #define	UART_FLAGS_FCR_RX_MEDL(f)	((f) & 0x200)
115 #define	UART_FLAGS_FCR_RX_MEDH(f)	((f) & 0x400)
116 #define	UART_FLAGS_FCR_RX_HIGH(f)	((f) & 0x800)
117 
118 /*
119  * Data parity values (magical numbers related to ns8250).
120  */
121 #define	UART_PARITY_NONE		0
122 #define	UART_PARITY_ODD			1
123 #define	UART_PARITY_EVEN		3
124 #define	UART_PARITY_MARK		5
125 #define	UART_PARITY_SPACE		7
126 
127 #endif /* _DEV_UART_H_ */
128