xref: /freebsd/sys/dev/uart/uart.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef _DEV_UART_H_
30 #define _DEV_UART_H_
31 
32 /*
33  * Bus access structure. This structure holds the minimum information needed
34  * to access the UART. The rclk field, although not important to actually
35  * access the UART, is important for baudrate programming, delay loops and
36  * other timing related computations.
37  */
38 struct uart_bas {
39 	bus_space_tag_t bst;
40 	bus_space_handle_t bsh;
41 	u_int	chan;
42 	u_int	rclk;
43 	u_int	regshft;
44 	u_int	regiowidth;
45 	u_int	busy_detect;
46 };
47 
48 #define	uart_regofs(bas, reg)		((reg) << (bas)->regshft)
49 #define	uart_regiowidth(bas)		((bas)->regiowidth)
50 
51 static inline uint32_t
52 uart_getreg(struct uart_bas *bas, int reg)
53 {
54 	uint32_t ret;
55 
56 	switch (uart_regiowidth(bas)) {
57 	case 4:
58 		ret = bus_space_read_4(bas->bst, bas->bsh, uart_regofs(bas, reg));
59 		break;
60 	case 2:
61 		ret = bus_space_read_2(bas->bst, bas->bsh, uart_regofs(bas, reg));
62 		break;
63 	default:
64 		ret = bus_space_read_1(bas->bst, bas->bsh, uart_regofs(bas, reg));
65 		break;
66 	}
67 
68 	return (ret);
69 }
70 
71 static inline void
72 uart_setreg(struct uart_bas *bas, int reg, int value)
73 {
74 
75 	switch (uart_regiowidth(bas)) {
76 	case 4:
77 		bus_space_write_4(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
78 		break;
79 	case 2:
80 		bus_space_write_2(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
81 		break;
82 	default:
83 		bus_space_write_1(bas->bst, bas->bsh, uart_regofs(bas, reg), value);
84 		break;
85 	}
86 }
87 
88 /*
89  * XXX we don't know the length of the bus space address range in use by
90  * the UART. Since barriers don't use the length field currently, we put
91  * a zero there for now.
92  */
93 #define uart_barrier(bas)		\
94 	bus_space_barrier((bas)->bst, (bas)->bsh, 0, 0,		\
95 	    BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE)
96 
97 /*
98  * UART device classes.
99  */
100 struct uart_class;
101 
102 extern struct uart_class uart_ns8250_class __attribute__((weak));
103 extern struct uart_class uart_quicc_class __attribute__((weak));
104 extern struct uart_class uart_z8530_class __attribute__((weak));
105 
106 /*
107  * Device flags.
108  */
109 #define	UART_FLAGS_CONSOLE(f)		((f) & 0x10)
110 #define	UART_FLAGS_DBGPORT(f)		((f) & 0x80)
111 #define	UART_FLAGS_FCR_RX_LOW(f)	((f) & 0x100)
112 #define	UART_FLAGS_FCR_RX_MEDL(f)	((f) & 0x200)
113 #define	UART_FLAGS_FCR_RX_MEDH(f)	((f) & 0x400)
114 #define	UART_FLAGS_FCR_RX_HIGH(f)	((f) & 0x800)
115 
116 /*
117  * Data parity values (magical numbers related to ns8250).
118  */
119 #define	UART_PARITY_NONE		0
120 #define	UART_PARITY_ODD			1
121 #define	UART_PARITY_EVEN		3
122 #define	UART_PARITY_MARK		5
123 #define	UART_PARITY_SPACE		7
124 
125 #endif /* _DEV_UART_H_ */
126