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 __FBSDID("$FreeBSD$");
33
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/cons.h>
38 #include <sys/consio.h>
39 #include <sys/kernel.h>
40
41 /* Allow it to be predefined, to be able to use another UART for console */
42 #ifndef IMX_UART_BASE
43 #define IMX_UART_BASE 0xe3fbc000 /* imx51 UART1 */
44 #endif
45
46 #define IMX_RXD 0x00
47 #define IMX_TXD 0x40
48
49 #define IMX_UFCR 0x90
50 #define IMX_USR1 0x94
51 #define IMX_USR1_TRDY (1 << 13)
52
53 #define IMX_USR2 0x98
54 #define IMX_USR2_RDR (1 << 0)
55 #define IMX_USR2_TXFE (1 << 14)
56 #define IMX_USR2_TXDC (1 << 3)
57
58 #define IMX_UTS 0xb4
59 #define IMX_UTS_TXFULL (1 << 4)
60
61 /*
62 * The base address of the uart registers.
63 *
64 * This is global so that it can be changed on the fly from the outside. For
65 * example, set imx_uart_base=physaddr and then call cninit() as the first two
66 * lines of initarm() and enjoy printf() availability through the tricky bits of
67 * startup. After initarm() switches from physical to virtual addressing, just
68 * set imx_uart_base=virtaddr and printf keeps working.
69 */
70 uint32_t imx_uart_base = IMX_UART_BASE;
71
72 /*
73 * uart related funcs
74 */
75 static uint32_t
76 ub_getreg(uint32_t off)
77 {
78
79 return *((volatile uint32_t *)(imx_uart_base + off));
80 }
81
82 static void
83 ub_setreg(uint32_t off, uint32_t val)
84 {
85
86 *((volatile uint32_t *)(imx_uart_base + off)) = val;
87 }
88
89 static int
90 ub_tstc(void)
91 {
92
93 return ((ub_getreg(IMX_USR2) & IMX_USR2_RDR) ? 1 : 0);
94 }
95
96 static int
97 ub_getc(void)
98 {
99
100 while (!ub_tstc());
101 __asm __volatile("nop");
102
103 return (ub_getreg(IMX_RXD) & 0xff);
104 }
105
106 static void
107 ub_putc(unsigned char c)
108 {
109
110 if (c == '\n')
111 ub_putc('\r');
112
113 while (ub_getreg(IMX_UTS) & IMX_UTS_TXFULL)
114 __asm __volatile("nop");
115
116 ub_setreg(IMX_TXD, c);
117 }
118
119 static cn_probe_t uart_cnprobe;
120 static cn_init_t uart_cninit;
121 static cn_term_t uart_cnterm;
122 static cn_getc_t uart_cngetc;
123 static cn_putc_t uart_cnputc;
124 static cn_grab_t uart_cngrab;
125 static cn_ungrab_t uart_cnungrab;
126
127 static void
128 uart_cngrab(struct consdev *cp)
129 {
130
131 }
132
133 static void
134 uart_cnungrab(struct consdev *cp)
135 {
136
137 }
138
139 static void
140 uart_cnprobe(struct consdev *cp)
141 {
142
143 sprintf(cp->cn_name, "uart");
144 cp->cn_pri = CN_NORMAL;
145 }
146
147 static void
148 uart_cninit(struct consdev *cp)
149 {
150
151 /* Init fifo trigger levels to 32 bytes, refclock div to 2. */
152 ub_setreg(IMX_UFCR, 0x00004210);
153 }
154
155 static void
156 uart_cnputc(struct consdev *cp, int c)
157 {
158
159 ub_putc(c);
160 }
161
162 static int
163 uart_cngetc(struct consdev * cp)
164 {
165
166 return ub_getc();
167 }
168
169 static void
170 uart_cnterm(struct consdev * cp)
171 {
172
173 }
174
175 CONSOLE_DRIVER(uart);
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