linux/drivers/hwtracing/stm/p_basic.c
Alexander Shishkin a02509f301 stm class: Factor out default framing protocol
The STP framing pattern that the stm class implicitly applies to the
data payload is, in fact, a protocol. This patch moves the relevant code
out of the stm core into its own driver module.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11 12:12:54 +02:00

49 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Basic framing protocol for STM devices.
* Copyright (c) 2018, Intel Corporation.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/stm.h>
#include "stm.h"
static ssize_t basic_write(struct stm_data *data, struct stm_output *output,
unsigned int chan, const char *buf, size_t count)
{
unsigned int c = output->channel + chan;
unsigned int m = output->master;
const unsigned char nil = 0;
ssize_t sz;
sz = stm_data_write(data, m, c, true, buf, count);
if (sz > 0)
data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
return sz;
}
static const struct stm_protocol_driver basic_pdrv = {
.owner = THIS_MODULE,
.name = "p_basic",
.write = basic_write,
};
static int basic_stm_init(void)
{
return stm_register_protocol(&basic_pdrv);
}
static void basic_stm_exit(void)
{
stm_unregister_protocol(&basic_pdrv);
}
module_init(basic_stm_init);
module_exit(basic_stm_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Basic STM framing protocol driver");
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");