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
15static int stm_console_link(struct stm_source_data *data);
16static void stm_console_unlink(struct stm_source_data *data);
17
18static 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
30static void
31stm_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(data: &sc->data, chan: 0, buf, count: len);
36}
37
38static 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(p: sc->console.name, q: "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
50static 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
57static int stm_console_init(void)
58{
59 return stm_source_register_device(NULL, data: &stm_console.data);
60}
61
62static void stm_console_exit(void)
63{
64 stm_source_unregister_device(data: &stm_console.data);
65}
66
67module_init(stm_console_init);
68module_exit(stm_console_exit);
69
70MODULE_LICENSE("GPL v2");
71MODULE_DESCRIPTION("stm_console driver");
72MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
73

source code of linux/drivers/hwtracing/stm/console.c