mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	To allow for more flexible testing of the stm class, make it possible to specify the ranges of masters and channels that the dummy_stm devices cover. This is done via module parameters. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
		
			
				
	
	
		
			125 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			125 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// 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>");
 |