linux_dsm_epyc7002/drivers/hwtracing/stm/dummy_stm.c
Alexander Shishkin 2c41538191 stm class: dummy_stm: Add dummy driver for testing stm class
This is a simple module that pretends to be an stm device and discards
all the data that comes in. Useful for testing stm class and its users.

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

67 lines
1.7 KiB
C

/*
* A dummy STM device for stm/stm_source class testing.
* 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 class implements generic infrastructure for System Trace Module devices
* as defined in MIPI STPv2 specification.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/stm.h>
static ssize_t
dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
unsigned int channel, unsigned int packet, unsigned int flags,
unsigned int size, const unsigned char *payload)
{
#ifdef DEBUG
u64 pl = 0;
if (payload)
pl = *(u64 *)payload;
if (size < 8)
pl &= (1ull << (size * 8)) - 1;
trace_printk("[%u:%u] [pkt: %x/%x] (%llx)\n", master, channel,
packet, size, pl);
#endif
return size;
}
static struct stm_data dummy_stm = {
.name = "dummy_stm",
.sw_start = 0x0000,
.sw_end = 0xffff,
.sw_nchannels = 0xffff,
.packet = dummy_stm_packet,
};
static int dummy_stm_init(void)
{
return stm_register_device(NULL, &dummy_stm, THIS_MODULE);
}
static void dummy_stm_exit(void)
{
stm_unregister_device(&dummy_stm);
}
module_init(dummy_stm_init);
module_exit(dummy_stm_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("dummy_stm device");
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");