xref: /freebsd/sys/arm/freescale/imx/imx_console.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * Copyright (c) 2012, 2013 The FreeBSD Foundation
3  *
4  * This software was developed by Oleksandr Rybalko under sponsorship
5  * from the FreeBSD Foundation.
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  * 1.	Redistributions of source code must retain the above copyright
11  *	notice, this list of conditions and the following disclaimer.
12  * 2.	Redistributions in binary form must reproduce the above copyright
13  *	notice, this list of conditions and the following disclaimer in the
14  *	documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /* Simple UART console driver for Freescale i.MX515 */
30 
31 #include <sys/cdefs.h>
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/cons.h>
36 #include <sys/consio.h>
37 #include <sys/kernel.h>
38 
39 /* Allow it to be predefined, to be able to use another UART for console */
40 #ifndef	IMX_UART_BASE
41 #define	IMX_UART_BASE	0xe3fbc000 /* imx51 UART1 */
42 #endif
43 
44 #define	IMX_RXD			0x00
45 #define	IMX_TXD			0x40
46 
47 #define	IMX_UFCR		0x90
48 #define	IMX_USR1		0x94
49 #define	IMX_USR1_TRDY		(1 << 13)
50 
51 #define	IMX_USR2		0x98
52 #define	IMX_USR2_RDR		(1 << 0)
53 #define	IMX_USR2_TXFE		(1 << 14)
54 #define	IMX_USR2_TXDC		(1 << 3)
55 
56 #define	IMX_UTS			0xb4
57 #define	IMX_UTS_TXFULL		(1 << 4)
58 
59 /*
60  * The base address of the uart registers.
61  *
62  * This is global so that it can be changed on the fly from the outside.  For
63  * example, set imx_uart_base=physaddr and then call cninit() as the first two
64  * lines of initarm() and enjoy printf() availability through the tricky bits of
65  * startup.  After initarm() switches from physical to virtual addressing, just
66  * set imx_uart_base=virtaddr and printf keeps working.
67  */
68 uint32_t imx_uart_base = IMX_UART_BASE;
69 
70 /*
71  * uart related funcs
72  */
73 static uint32_t
74 ub_getreg(uint32_t off)
75 {
76 
77 	return *((volatile uint32_t *)(imx_uart_base + off));
78 }
79 
80 static void
81 ub_setreg(uint32_t off, uint32_t val)
82 {
83 
84 	*((volatile uint32_t *)(imx_uart_base + off)) = val;
85 }
86 
87 static int
88 ub_tstc(void)
89 {
90 
91 	return ((ub_getreg(IMX_USR2) & IMX_USR2_RDR) ? 1 : 0);
92 }
93 
94 static int
95 ub_getc(void)
96 {
97 
98 	while (!ub_tstc());
99 		__asm __volatile("nop");
100 
101 	return (ub_getreg(IMX_RXD) & 0xff);
102 }
103 
104 static void
105 ub_putc(unsigned char c)
106 {
107 
108 	if (c == '\n')
109 		ub_putc('\r');
110 
111 	while (ub_getreg(IMX_UTS) & IMX_UTS_TXFULL)
112 		__asm __volatile("nop");
113 
114 	ub_setreg(IMX_TXD, c);
115 }
116 
117 static cn_probe_t	uart_cnprobe;
118 static cn_init_t	uart_cninit;
119 static cn_term_t	uart_cnterm;
120 static cn_getc_t	uart_cngetc;
121 static cn_putc_t	uart_cnputc;
122 static cn_grab_t	uart_cngrab;
123 static cn_ungrab_t	uart_cnungrab;
124 
125 static void
126 uart_cngrab(struct consdev *cp)
127 {
128 
129 }
130 
131 static void
132 uart_cnungrab(struct consdev *cp)
133 {
134 
135 }
136 
137 static void
138 uart_cnprobe(struct consdev *cp)
139 {
140 
141         sprintf(cp->cn_name, "uart");
142         cp->cn_pri = CN_NORMAL;
143 }
144 
145 static void
146 uart_cninit(struct consdev *cp)
147 {
148 
149         /* Init fifo trigger levels to 32 bytes, refclock div to 2. */
150 	ub_setreg(IMX_UFCR, 0x00004210);
151 }
152 
153 static void
154 uart_cnputc(struct consdev *cp, int c)
155 {
156 
157 	ub_putc(c);
158 }
159 
160 static int
161 uart_cngetc(struct consdev * cp)
162 {
163 
164 	return ub_getc();
165 }
166 
167 static void
168 uart_cnterm(struct consdev * cp)
169 {
170 
171 }
172 
173 CONSOLE_DRIVER(uart);
174