1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2008
4  * Gary Jennejohn, DENX Software Engineering GmbH, garyj@denx.de.
5  */
6 
7 #include <common.h>
8 #include <console.h>
9 #include <serial.h>
10 #include <malloc.h>
11 
12 #if CONFIG_IS_ENABLED(CONSOLE_MUX)
iomux_printdevs(const int console)13 void iomux_printdevs(const int console)
14 {
15 	int i;
16 	struct stdio_dev *dev;
17 
18 	for_each_console_dev(i, console, dev)
19 		printf("%s ", dev->name);
20 	printf("\n");
21 }
22 
iomux_match_device(struct stdio_dev ** set,const int n,struct stdio_dev * sdev)23 int iomux_match_device(struct stdio_dev **set, const int n, struct stdio_dev *sdev)
24 {
25 	int i;
26 
27 	for (i = 0; i < n; i++)
28 		if (sdev == set[i])
29 			return i;
30 	return -ENOENT;
31 }
32 
33 /* This tries to preserve the old list if an error occurs. */
iomux_doenv(const int console,const char * arg)34 int iomux_doenv(const int console, const char *arg)
35 {
36 	char *console_args, *temp, **start;
37 	int i, j, io_flag, cs_idx, repeat;
38 	struct stdio_dev **cons_set, **old_set;
39 	struct stdio_dev *dev;
40 
41 	console_args = strdup(arg);
42 	if (console_args == NULL)
43 		return 1;
44 	/*
45 	 * Check whether a comma separated list of devices was
46 	 * entered and count how many devices were entered.
47 	 * The array start[] has pointers to the beginning of
48 	 * each device name (up to MAX_CONSARGS devices).
49 	 *
50 	 * Have to do this twice - once to count the number of
51 	 * commas and then again to populate start.
52 	 */
53 	i = 0;
54 	temp = console_args;
55 	for (;;) {
56 		/* There's always one entry more than the number of commas. */
57 		i++;
58 
59 		temp = strchr(temp, ',');
60 		if (temp == NULL)
61 			break;
62 
63 		temp++;
64 	}
65 	start = (char **)malloc(i * sizeof(char *));
66 	if (start == NULL) {
67 		free(console_args);
68 		return 1;
69 	}
70 	i = 0;
71 	start[0] = console_args;
72 	for (;;) {
73 		temp = strchr(start[i++], ',');
74 		if (temp == NULL)
75 			break;
76 		*temp = '\0';
77 		start[i] = temp + 1;
78 	}
79 	cons_set = (struct stdio_dev **)calloc(i, sizeof(struct stdio_dev *));
80 	if (cons_set == NULL) {
81 		free(start);
82 		free(console_args);
83 		return 1;
84 	}
85 
86 	io_flag = stdio_file_to_flags(console);
87 	if (io_flag < 0) {
88 		free(start);
89 		free(console_args);
90 		free(cons_set);
91 		return 1;
92 	}
93 
94 	cs_idx = 0;
95 	for (j = 0; j < i; j++) {
96 		/*
97 		 * Check whether the device exists and is valid.
98 		 * console_assign() also calls console_search_dev(),
99 		 * but I need the pointer to the device.
100 		 */
101 		dev = console_search_dev(io_flag, start[j]);
102 		if (dev == NULL)
103 			continue;
104 		/*
105 		 * Prevent multiple entries for a device.
106 		 */
107 		 repeat = iomux_match_device(cons_set, cs_idx, dev);
108 		 if (repeat >= 0)
109 			continue;
110 		/*
111 		 * Try assigning the specified device.
112 		 * This could screw up the console settings for apps.
113 		 */
114 		if (console_assign(console, start[j]) < 0)
115 			continue;
116 		cons_set[cs_idx++] = dev;
117 	}
118 	free(console_args);
119 	free(start);
120 	/* failed to set any console */
121 	if (cs_idx == 0) {
122 		free(cons_set);
123 		return 1;
124 	}
125 
126 	old_set = console_devices[console];
127 	repeat = cd_count[console];
128 
129 	console_devices[console] = cons_set;
130 	cd_count[console] = cs_idx;
131 
132 	/* Stop dropped consoles */
133 	for (i = 0; i < repeat; i++) {
134 		j = iomux_match_device(cons_set, cs_idx, old_set[i]);
135 		if (j == cs_idx)
136 			console_stop(console, old_set[i]);
137 	}
138 
139 	free(old_set);
140 	return 0;
141 }
142 
iomux_replace_device(const int console,const char * old,const char * new)143 int iomux_replace_device(const int console, const char *old, const char *new)
144 {
145 	struct stdio_dev *dev;
146 	char *arg = NULL;	/* Initial empty list */
147 	int size = 1;		/* For NUL terminator */
148 	int i, ret;
149 
150 	for_each_console_dev(i, console, dev) {
151 		const char *name = strcmp(dev->name, old) ? dev->name : new;
152 		char *tmp;
153 
154 		/* Append name with a ',' (comma) separator */
155 		tmp = realloc(arg, size + strlen(name) + 1);
156 		if (!tmp) {
157 			free(arg);
158 			return -ENOMEM;
159 		}
160 
161 		strcat(tmp, ",");
162 		strcat(tmp, name);
163 
164 		arg = tmp;
165 		size = strlen(tmp) + 1;
166 	}
167 
168 	ret = iomux_doenv(console, arg);
169 	if (ret)
170 		ret = -EINVAL;
171 
172 	free(arg);
173 	return ret;
174 }
175 #endif /* CONSOLE_MUX */
176