GNU Linux-libre 4.19.314-gnu1
[releases.git] / drivers / hwtracing / stm / console.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Simple kernel console driver for STM devices
4  * Copyright (c) 2014, Intel Corporation.
5  *
6  * STM console will send kernel messages over STM devices to a trace host.
7  */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/console.h>
12 #include <linux/slab.h>
13 #include <linux/stm.h>
14
15 static int stm_console_link(struct stm_source_data *data);
16 static void stm_console_unlink(struct stm_source_data *data);
17
18 static struct stm_console {
19         struct stm_source_data  data;
20         struct console          console;
21 } stm_console = {
22         .data   = {
23                 .name           = "console",
24                 .nr_chans       = 1,
25                 .link           = stm_console_link,
26                 .unlink         = stm_console_unlink,
27         },
28 };
29
30 static void
31 stm_console_write(struct console *con, const char *buf, unsigned len)
32 {
33         struct stm_console *sc = container_of(con, struct stm_console, console);
34
35         stm_source_write(&sc->data, 0, buf, len);
36 }
37
38 static int stm_console_link(struct stm_source_data *data)
39 {
40         struct stm_console *sc = container_of(data, struct stm_console, data);
41
42         strcpy(sc->console.name, "stm_console");
43         sc->console.write = stm_console_write;
44         sc->console.flags = CON_ENABLED | CON_PRINTBUFFER;
45         register_console(&sc->console);
46
47         return 0;
48 }
49
50 static void stm_console_unlink(struct stm_source_data *data)
51 {
52         struct stm_console *sc = container_of(data, struct stm_console, data);
53
54         unregister_console(&sc->console);
55 }
56
57 static int stm_console_init(void)
58 {
59         return stm_source_register_device(NULL, &stm_console.data);
60 }
61
62 static void stm_console_exit(void)
63 {
64         stm_source_unregister_device(&stm_console.data);
65 }
66
67 module_init(stm_console_init);
68 module_exit(stm_console_exit);
69
70 MODULE_LICENSE("GPL v2");
71 MODULE_DESCRIPTION("stm_console driver");
72 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");