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