linux/drivers/hwtracing/stm/console.c
Alexander Shishkin e3e5a3d3da stm class: stm_console: Add kernel-console-over-stm driver
This is a simple stm_source class device driver (kernelspace stm trace
source) that registers a console and sends kernel messages over STM
devices.

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 20:28:58 +01:00

81 lines
2.1 KiB
C

/*
* Simple kernel console driver for STM devices
* Copyright (c) 2014, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* STM console will send kernel messages over STM devices to a trace host.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/slab.h>
#include <linux/stm.h>
static int stm_console_link(struct stm_source_data *data);
static void stm_console_unlink(struct stm_source_data *data);
static struct stm_console {
struct stm_source_data data;
struct console console;
} stm_console = {
.data = {
.name = "console",
.nr_chans = 1,
.link = stm_console_link,
.unlink = stm_console_unlink,
},
};
static void
stm_console_write(struct console *con, const char *buf, unsigned len)
{
struct stm_console *sc = container_of(con, struct stm_console, console);
stm_source_write(&sc->data, 0, buf, len);
}
static int stm_console_link(struct stm_source_data *data)
{
struct stm_console *sc = container_of(data, struct stm_console, data);
strcpy(sc->console.name, "stm_console");
sc->console.write = stm_console_write;
sc->console.flags = CON_ENABLED | CON_PRINTBUFFER;
register_console(&sc->console);
return 0;
}
static void stm_console_unlink(struct stm_source_data *data)
{
struct stm_console *sc = container_of(data, struct stm_console, data);
unregister_console(&sc->console);
}
static int stm_console_init(void)
{
return stm_source_register_device(NULL, &stm_console.data);
}
static void stm_console_exit(void)
{
stm_source_unregister_device(&stm_console.data);
}
module_init(stm_console_init);
module_exit(stm_console_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("stm_console driver");
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");