xref: /freebsd/sys/arm/freescale/imx/imx_console.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 /*-
2  * Copyright (c) 2012, 2013 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Oleksandr Rybalko under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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 AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /* Simple UART console driver for Freescale i.MX515 */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/cons.h>
39 #include <sys/consio.h>
40 #include <sys/kernel.h>
41 
42 /* Allow it to be predefined, to be able to use another UART for console */
43 #ifndef	IMX_UART_BASE
44 #define	IMX_UART_BASE	0xe3fbc000 /* imx51 UART1 */
45 #endif
46 
47 #define	IMX_RXD			0x00
48 #define	IMX_TXD			0x40
49 
50 #define	IMX_UFCR		0x90
51 #define	IMX_USR1		0x94
52 #define	IMX_USR1_TRDY		(1 << 13)
53 
54 #define	IMX_USR2		0x98
55 #define	IMX_USR2_RDR		(1 << 0)
56 #define	IMX_USR2_TXFE		(1 << 14)
57 #define	IMX_USR2_TXDC		(1 << 3)
58 
59 #define	IMX_UTS			0xb4
60 #define	IMX_UTS_TXFULL		(1 << 4)
61 
62 /*
63  * The base address of the uart registers.
64  *
65  * This is global so that it can be changed on the fly from the outside.  For
66  * example, set imx_uart_base=physaddr and then call cninit() as the first two
67  * lines of initarm() and enjoy printf() availability through the tricky bits of
68  * startup.  After initarm() switches from physical to virtual addressing, just
69  * set imx_uart_base=virtaddr and printf keeps working.
70  */
71 uint32_t imx_uart_base = IMX_UART_BASE;
72 
73 /*
74  * uart related funcs
75  */
76 static uint32_t
77 ub_getreg(uint32_t off)
78 {
79 
80 	return *((volatile uint32_t *)(imx_uart_base + off));
81 }
82 
83 static void
84 ub_setreg(uint32_t off, uint32_t val)
85 {
86 
87 	*((volatile uint32_t *)(imx_uart_base + off)) = val;
88 }
89 
90 static int
91 ub_tstc(void)
92 {
93 
94 	return ((ub_getreg(IMX_USR2) & IMX_USR2_RDR) ? 1 : 0);
95 }
96 
97 static int
98 ub_getc(void)
99 {
100 
101 	while (!ub_tstc());
102 		__asm __volatile("nop");
103 
104 	return (ub_getreg(IMX_RXD) & 0xff);
105 }
106 
107 static void
108 ub_putc(unsigned char c)
109 {
110 
111 	if (c == '\n')
112 		ub_putc('\r');
113 
114 	while (ub_getreg(IMX_UTS) & IMX_UTS_TXFULL)
115 		__asm __volatile("nop");
116 
117 	ub_setreg(IMX_TXD, c);
118 }
119 
120 static cn_probe_t	uart_cnprobe;
121 static cn_init_t	uart_cninit;
122 static cn_term_t	uart_cnterm;
123 static cn_getc_t	uart_cngetc;
124 static cn_putc_t	uart_cnputc;
125 static cn_grab_t	uart_cngrab;
126 static cn_ungrab_t	uart_cnungrab;
127 
128 static void
129 uart_cngrab(struct consdev *cp)
130 {
131 
132 }
133 
134 static void
135 uart_cnungrab(struct consdev *cp)
136 {
137 
138 }
139 
140 static void
141 uart_cnprobe(struct consdev *cp)
142 {
143 
144         sprintf(cp->cn_name, "uart");
145         cp->cn_pri = CN_NORMAL;
146 }
147 
148 static void
149 uart_cninit(struct consdev *cp)
150 {
151 
152         /* Init fifo trigger levels to 32 bytes, refclock div to 2. */
153 	ub_setreg(IMX_UFCR, 0x00004210);
154 }
155 
156 static void
157 uart_cnputc(struct consdev *cp, int c)
158 {
159 
160 	ub_putc(c);
161 }
162 
163 static int
164 uart_cngetc(struct consdev * cp)
165 {
166 
167 	return ub_getc();
168 }
169 
170 static void
171 uart_cnterm(struct consdev * cp)
172 {
173 
174 }
175 
176 CONSOLE_DRIVER(uart);
177