xref: /openbmc/u-boot/common/iomux.c (revision 2a046ff5)
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)
13 void iomux_printdevs(const int console)
14 {
15 	int i;
16 	struct stdio_dev *dev;
17 
18 	for (i = 0; i < cd_count[console]; i++) {
19 		dev = console_devices[console][i];
20 		printf("%s ", dev->name);
21 	}
22 	printf("\n");
23 }
24 
25 /* This tries to preserve the old list if an error occurs. */
26 int iomux_doenv(const int console, const char *arg)
27 {
28 	char *console_args, *temp, **start;
29 	int i, j, k, io_flag, cs_idx, repeat;
30 	struct stdio_dev *dev;
31 	struct stdio_dev **cons_set;
32 
33 	console_args = strdup(arg);
34 	if (console_args == NULL)
35 		return 1;
36 	/*
37 	 * Check whether a comma separated list of devices was
38 	 * entered and count how many devices were entered.
39 	 * The array start[] has pointers to the beginning of
40 	 * each device name (up to MAX_CONSARGS devices).
41 	 *
42 	 * Have to do this twice - once to count the number of
43 	 * commas and then again to populate start.
44 	 */
45 	i = 0;
46 	temp = console_args;
47 	for (;;) {
48 		temp = strchr(temp, ',');
49 		if (temp != NULL) {
50 			i++;
51 			temp++;
52 			continue;
53 		}
54 		/* There's always one entry more than the number of commas. */
55 		i++;
56 		break;
57 	}
58 	start = (char **)malloc(i * sizeof(char *));
59 	if (start == NULL) {
60 		free(console_args);
61 		return 1;
62 	}
63 	i = 0;
64 	start[0] = console_args;
65 	for (;;) {
66 		temp = strchr(start[i++], ',');
67 		if (temp == NULL)
68 			break;
69 		*temp = '\0';
70 		start[i] = temp + 1;
71 	}
72 	cons_set = (struct stdio_dev **)calloc(i, sizeof(struct stdio_dev *));
73 	if (cons_set == NULL) {
74 		free(start);
75 		free(console_args);
76 		return 1;
77 	}
78 
79 	switch (console) {
80 	case stdin:
81 		io_flag = DEV_FLAGS_INPUT;
82 		break;
83 	case stdout:
84 	case stderr:
85 		io_flag = DEV_FLAGS_OUTPUT;
86 		break;
87 	default:
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 search_device(),
99 		 * but I need the pointer to the device.
100 		 */
101 		dev = search_device(io_flag, start[j]);
102 		if (dev == NULL)
103 			continue;
104 		/*
105 		 * Prevent multiple entries for a device.
106 		 */
107 		 repeat = 0;
108 		 for (k = 0; k < cs_idx; k++) {
109 			if (dev == cons_set[k]) {
110 				repeat++;
111 				break;
112 			}
113 		 }
114 		 if (repeat)
115 			continue;
116 		/*
117 		 * Try assigning the specified device.
118 		 * This could screw up the console settings for apps.
119 		 */
120 		if (console_assign(console, start[j]) < 0)
121 			continue;
122 		cons_set[cs_idx++] = dev;
123 	}
124 	free(console_args);
125 	free(start);
126 	/* failed to set any console */
127 	if (cs_idx == 0) {
128 		free(cons_set);
129 		return 1;
130 	} else {
131 		/* Works even if console_devices[console] is NULL. */
132 		console_devices[console] =
133 			(struct stdio_dev **)realloc(console_devices[console],
134 			cs_idx * sizeof(struct stdio_dev *));
135 		if (console_devices[console] == NULL) {
136 			free(cons_set);
137 			return 1;
138 		}
139 		memcpy(console_devices[console], cons_set, cs_idx *
140 			sizeof(struct stdio_dev *));
141 
142 		cd_count[console] = cs_idx;
143 	}
144 	free(cons_set);
145 	return 0;
146 }
147 #endif /* CONSOLE_MUX */
148