1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Generic serial console support
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
8 * and was written by Matt Porter <mporter@kernel.crashing.org>.
9 *
10 * 2001,2006 (c) MontaVista Software, Inc.
11 */
12 #include <stdarg.h>
13 #include <stddef.h>
14 #include "types.h"
15 #include "string.h"
16 #include "stdio.h"
17 #include "io.h"
18 #include "ops.h"
19
20 static int serial_open(void)
21 {
22 struct serial_console_data *scdp = console_ops.data;
23 return scdp->open();
24 }
25
26 static void serial_write(const char *buf, int len)
27 {
28 struct serial_console_data *scdp = console_ops.data;
29
30 while (*buf != '\0')
31 scdp->putc(*buf++);
32 }
33
34 static void serial_edit_cmdline(char *buf, int len, unsigned int timeout)
35 {
36 int timer = 0, count;
37 char ch, *cp;
38 struct serial_console_data *scdp = console_ops.data;
39
40 cp = buf;
41 count = strlen(buf);
42 cp = &buf[count];
43 count++;
44
45 do {
46 if (scdp->tstc()) {
47 while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
48 /* Test for backspace/delete */
49 if ((ch == '\b') || (ch == '\177')) {
50 if (cp != buf) {
51 cp--;
52 count--;
53 printf("\b \b");
54 }
55 /* Test for ^x/^u (and wipe the line) */
56 } else if ((ch == '\030') || (ch == '\025')) {
57 while (cp != buf) {
58 cp--;
59 count--;
60 printf("\b \b");
61 }
62 } else if (count < len) {
63 *cp++ = ch;
64 count++;
65 scdp->putc(ch);
66 }
67 }
68 break; /* Exit 'timer' loop */
69 }
70 udelay(1000); /* 1 msec */
71 } while (timer++ < timeout);
72 *cp = 0;
73 }
74
75 static void serial_close(void)
76 {
77 struct serial_console_data *scdp = console_ops.data;
78
79 if (scdp->close)
80 scdp->close();
81 }
82
83 static void *serial_get_stdout_devp(void)
84 {
85 void *devp;
86 char devtype[MAX_PROP_LEN];
87 char path[MAX_PATH_LEN];
88
89 devp = finddevice("/chosen");
90 if (devp == NULL)
91 goto err_out;
92
93 if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 ||
94 getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) {
95 devp = finddevice(path);
96 if (devp == NULL)
97 goto err_out;
98
99 if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
100 && !strcmp(devtype, "serial"))
101 return devp;
102 }
103 err_out:
104 return NULL;
105 }
106
107 static struct serial_console_data serial_cd;
108
109 /* Node's "compatible" property determines which serial driver to use */
110 int serial_console_init(void)
111 {
112 void *devp;
113 int rc = -1;
114
115 devp = serial_get_stdout_devp();
116 if (devp == NULL)
117 goto err_out;
118
119 if (dt_is_compatible(devp, "ns16550") ||
120 dt_is_compatible(devp, "pnpPNP,501"))
121 rc = ns16550_console_init(devp, &serial_cd);
122 #ifdef CONFIG_CPM
123 else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") ||
124 dt_is_compatible(devp, "fsl,cpm1-smc-uart") ||
125 dt_is_compatible(devp, "fsl,cpm2-scc-uart") ||
126 dt_is_compatible(devp, "fsl,cpm2-smc-uart"))
127 rc = cpm_console_init(devp, &serial_cd);
128 #endif
129 #ifdef CONFIG_PPC_MPC52xx
130 else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart"))
131 rc = mpc5200_psc_console_init(devp, &serial_cd);
132 #endif
133 #ifdef CONFIG_PPC_POWERNV
134 else if (dt_is_compatible(devp, "ibm,opal-console-raw"))
135 rc = opal_console_init(devp, &serial_cd);
136 #endif
137
138 /* Add other serial console driver calls here */
139
140 if (!rc) {
141 console_ops.open = serial_open;
142 console_ops.write = serial_write;
143 console_ops.close = serial_close;
144 console_ops.data = &serial_cd;
145
146 if (serial_cd.getc)
147 console_ops.edit_cmdline = serial_edit_cmdline;
148
149 return 0;
150 }
151 err_out:
152 return -1;
153 }
154
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