1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2017, Linaro Limited
4 */
5
6 #include <compiler.h>
7 #include <console.h>
8 #include <drivers/serial.h>
9 #include <kernel/dt.h>
10 #include <kernel/boot.h>
11 #include <kernel/panic.h>
12 #include <libfdt.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <string_ext.h>
16
17 static struct serial_chip *serial_console __nex_bss;
18
console_putc(int ch)19 void __weak console_putc(int ch)
20 {
21 if (!serial_console)
22 return;
23
24 if (ch == '\n')
25 serial_console->ops->putc(serial_console, '\r');
26 serial_console->ops->putc(serial_console, ch);
27 }
28
console_flush(void)29 void __weak console_flush(void)
30 {
31 if (!serial_console || !serial_console->ops->flush)
32 return;
33
34 serial_console->ops->flush(serial_console);
35 }
36
register_serial_console(struct serial_chip * chip)37 void register_serial_console(struct serial_chip *chip)
38 {
39 serial_console = chip;
40 }
41
42 #ifdef CFG_DT
find_chosen_node(void * fdt)43 static int find_chosen_node(void *fdt)
44 {
45 int offset = 0;
46
47 if (!fdt)
48 return -1;
49
50 offset = fdt_path_offset(fdt, "/secure-chosen");
51
52 if (offset < 0)
53 offset = fdt_path_offset(fdt, "/chosen");
54
55 return offset;
56 }
57
get_console_node_from_dt(void * fdt,int * offs_out,char ** path_out,char ** params_out)58 TEE_Result get_console_node_from_dt(void *fdt, int *offs_out,
59 char **path_out, char **params_out)
60 {
61 const struct fdt_property *prop;
62 const char *uart;
63 const char *parms = NULL;
64 int offs;
65 char *stdout_data;
66 char *p;
67 TEE_Result rc = TEE_ERROR_GENERIC;
68
69 /* Probe console from secure DT and fallback to non-secure DT */
70 offs = find_chosen_node(fdt);
71 if (offs < 0) {
72 DMSG("No console directive from DTB");
73 return TEE_ERROR_ITEM_NOT_FOUND;
74 }
75
76 prop = fdt_get_property(fdt, offs, "stdout-path", NULL);
77 if (!prop) {
78 /*
79 * A secure-chosen or chosen node is present but defined
80 * no stdout-path property: no console expected
81 */
82 IMSG("Switching off console");
83 register_serial_console(NULL);
84 return TEE_ERROR_ITEM_NOT_FOUND;
85 }
86
87 stdout_data = nex_strdup(prop->data);
88 if (!stdout_data)
89 panic();
90 p = strchr(stdout_data, ':');
91 if (p) {
92 *p = '\0';
93 parms = p + 1;
94 }
95
96 /* stdout-path may refer to an alias */
97 uart = fdt_get_alias(fdt, stdout_data);
98 if (!uart) {
99 /* Not an alias, assume we have a node path */
100 uart = stdout_data;
101 }
102 offs = fdt_path_offset(fdt, uart);
103 if (offs >= 0) {
104 if (offs_out)
105 *offs_out = offs;
106 if (params_out)
107 *params_out = parms ? nex_strdup(parms) : NULL;
108 if (path_out)
109 *path_out = uart ? nex_strdup(uart) : NULL;
110
111 rc = TEE_SUCCESS;
112 }
113
114 nex_free(stdout_data);
115
116 return rc;
117 }
118
configure_console_from_dt(void)119 void configure_console_from_dt(void)
120 {
121 const struct dt_driver *dt_drv;
122 const struct serial_driver *sdrv;
123 struct serial_chip *dev;
124 char *uart = NULL;
125 char *parms = NULL;
126 void *fdt;
127 int offs;
128
129 fdt = get_dt();
130 if (get_console_node_from_dt(fdt, &offs, &uart, &parms))
131 return;
132
133 dt_drv = dt_find_compatible_driver(fdt, offs);
134 if (!dt_drv || dt_drv->type != DT_DRIVER_UART)
135 goto out;
136
137 sdrv = (const struct serial_driver *)dt_drv->driver;
138 if (!sdrv)
139 goto out;
140
141 dev = sdrv->dev_alloc();
142 if (!dev)
143 goto out;
144
145 /*
146 * If the console is the same as the early console, dev_init() might
147 * clear pending data. Flush to avoid that.
148 */
149 console_flush();
150 if (sdrv->dev_init(dev, fdt, offs, parms) < 0) {
151 sdrv->dev_free(dev);
152 goto out;
153 }
154
155 IMSG("Switching console to device: %s", uart);
156 register_serial_console(dev);
157 out:
158 nex_free(uart);
159 nex_free(parms);
160 }
161
162 #endif /* CFG_DT */
163