Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * A dummy STM device for stm/stm_source class testing.
 * Copyright (c) 2014, Intel Corporation.
 *
 * 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>
#include <uapi/linux/stm.h>
 
static ssize_t notrace
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;
}
 
#define DUMMY_STM_MAX 32
 
static struct stm_data dummy_stm[DUMMY_STM_MAX];
 
static int nr_dummies = 4;
 
module_param(nr_dummies, int, 0400);
 
static unsigned int fail_mode;
 
module_param(fail_mode, int, 0600);
 
static unsigned int master_min;
 
module_param(master_min, int, 0400);
 
static unsigned int master_max = STP_MASTER_MAX;
 
module_param(master_max, int, 0400);
 
static unsigned int nr_channels = STP_CHANNEL_MAX;
 
module_param(nr_channels, int, 0400);
 
static int dummy_stm_link(struct stm_data *data, unsigned int master,
<------><------><------>  unsigned int channel)
{
<------>if (fail_mode && (channel & fail_mode))
<------><------>return -EINVAL;
 
<------>return 0;
}
 
static int dummy_stm_init(void)
{
<------>int i, ret = -ENOMEM;
 
<------>if (nr_dummies < 0 || nr_dummies > DUMMY_STM_MAX)
<------><------>return -EINVAL;
 
<------>if (master_min > master_max ||
<------>    master_max > STP_MASTER_MAX ||
<------>    nr_channels > STP_CHANNEL_MAX)
<------><------>return -EINVAL;
 
<------>for (i = 0; i < nr_dummies; i++) {
<------><------>dummy_stm[i].name = kasprintf(GFP_KERNEL, "dummy_stm.%d", i);
<------><------>if (!dummy_stm[i].name)
<------><------><------>goto fail_unregister;
 
<------><------>dummy_stm[i].sw_start		= master_min;
<------><------>dummy_stm[i].sw_end		= master_max;
<------><------>dummy_stm[i].sw_nchannels	= nr_channels;
<------><------>dummy_stm[i].packet		= dummy_stm_packet;
<------><------>dummy_stm[i].link		= dummy_stm_link;
 
<------><------>ret = stm_register_device(NULL, &dummy_stm[i], THIS_MODULE);
<------><------>if (ret)
<------><------><------>goto fail_free;
<------>}
 
<------>return 0;
 
fail_unregister:
<------>for (i--; i >= 0; i--) {
<------><------>stm_unregister_device(&dummy_stm[i]);
fail_free:
<------><------>kfree(dummy_stm[i].name);
<------>}
 
<------>return ret;
 
}
 
static void dummy_stm_exit(void)
{
<------>int i;
 
<------>for (i = 0; i < nr_dummies; i++) {
<------><------>stm_unregister_device(&dummy_stm[i]);
<------><------>kfree(dummy_stm[i].name);
<------>}
}
 
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>");