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