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
ub_getreg(uint32_t off)74 ub_getreg(uint32_t off)
75 {
76
77 return *((volatile uint32_t *)(imx_uart_base + off));
78 }
79
80 static void
ub_setreg(uint32_t off,uint32_t val)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
ub_tstc(void)88 ub_tstc(void)
89 {
90
91 return ((ub_getreg(IMX_USR2) & IMX_USR2_RDR) ? 1 : 0);
92 }
93
94 static int
ub_getc(void)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
ub_putc(unsigned char c)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
uart_cngrab(struct consdev * cp)126 uart_cngrab(struct consdev *cp)
127 {
128
129 }
130
131 static void
uart_cnungrab(struct consdev * cp)132 uart_cnungrab(struct consdev *cp)
133 {
134
135 }
136
137 static void
uart_cnprobe(struct consdev * cp)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
uart_cninit(struct consdev * cp)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
uart_cnputc(struct consdev * cp,int c)154 uart_cnputc(struct consdev *cp, int c)
155 {
156
157 ub_putc(c);
158 }
159
160 static int
uart_cngetc(struct consdev * cp)161 uart_cngetc(struct consdev * cp)
162 {
163
164 return ub_getc();
165 }
166
167 static void
uart_cnterm(struct consdev * cp)168 uart_cnterm(struct consdev * cp)
169 {
170
171 }
172
173 CONSOLE_DRIVER(uart);
174