bizhang_-obav/src/platforms/qurt/px4_layer/shmem_qurt.c

/****************************************************************************
 *
 * Copyright (c) 2015 Vijay Venkatraman. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#include <px4_defines.h>
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <atomic_ops.h>

#include "systemlib/param/param.h"

#include <shmem.h>
#include <drivers/drv_hrt.h>

#define SHMEM_DEBUG

int mem_fd;
unsigned char *map_base, *virt_addr;
struct shmem_info* shmem_info_p;
static void* map_memory(off_t target);
int get_shmem_lock(void);
void release_shmem_lock(void);
void init_shared_memory(void);
void copy_params_to_shmem(struct param_info_s *);
void update_to_shmem(param_t param, union param_value_u value);
int update_from_shmem(param_t param, union param_value_u *value);
uint64_t update_from_shmem_prev_time=0, update_from_shmem_current_time=0;
static unsigned char krait_changed_index[MAX_SHMEM_PARAMS/8+1];

struct param_wbuf_s {
	param_t			param;
	union param_value_u	val;
	bool			unsaved;
};
extern struct param_wbuf_s * param_find_changed(param_t param);

static void* map_memory(off_t target)
{

    return (void*)(target+LOCK_SIZE);

}

int get_shmem_lock(void)
{
	unsigned char *lock = (unsigned char*)(MAP_ADDRESS+LOCK_OFFSET);
	unsigned int i=0;

	while(!atomic_compare_and_set(lock, 1, 0))
	{
		PX4_INFO("Could not get lock. spinning\n");
		i++;
		usleep(1000);
		if(i>100) break;
	}

	if(i>100) return -1;

	return 0; //got the lock

}

void release_shmem_lock(void)
{
	unsigned char *lock = (unsigned char*)(MAP_ADDRESS+LOCK_OFFSET);

	*lock=1;
	return;
}

void init_shared_memory(void)
{
	//PX4_INFO("Value at lock address is %d\n", *(unsigned int*)0xfbfc000);

	virt_addr = map_memory(MAP_ADDRESS);
	shmem_info_p = (struct shmem_info*)virt_addr;

	//PX4_INFO("adsp memory mapped\n");
}

void copy_params_to_shmem(struct param_info_s *param_info_base)
{
	param_t	param;
	unsigned int i;

	if(get_shmem_lock()!=0) {
		PX4_INFO("Could not get shmem lock\n");
		return;
	}			
	//else PX4_INFO("Got lock\n");

	for (param = 0; param<param_count(); param++) {
		//{PX4_INFO("writing to offset %d\n", (unsigned char*)(shmem_info_p->adsp_params[param].name)-(unsigned char*)shmem_info_p);}
		struct param_wbuf_s *s = param_find_changed(param);
		if(s==NULL) shmem_info_p->params_val[param] = param_info_base[param].val; 
		else shmem_info_p->params_val[param] = s->val; 

#ifdef SHMEM_DEBUG
		if(param_type(param)==PARAM_TYPE_INT32){
		PX4_INFO("%d: written %d for param %s to shared mem", param, shmem_info_p->params_val[param].i, param_name(param));}
		else if(param_type(param)==PARAM_TYPE_FLOAT){
		PX4_INFO("%d: written %f for param %s to shared mem", param, shmem_info_p->params_val[param].f, param_name(param));}
#endif
	}
	
	for(i=0;i<MAX_SHMEM_PARAMS/8+1;i++)
	{
		shmem_info_p->adsp_changed_index[i]=0;
		krait_changed_index[i]=0;
	}

	release_shmem_lock();
	//PX4_INFO("Released lock\n");

}


/*update value and param's change bit in shared memory*/
void update_to_shmem(param_t param, union param_value_u value)
{
	unsigned int byte_changed, bit_changed;

	if(!handle_in_range(param))
		return;

	if(get_shmem_lock()!=0) {
		PX4_ERR("Could not get shmem lock\n");
		return;
	}			

	shmem_info_p->params_val[param] = value;

	byte_changed = param/8;
	bit_changed = 1 << param%8;
	shmem_info_p->adsp_changed_index[byte_changed]|=bit_changed;

	//PX4_INFO("set %d bit on adsp index[%d] to %d\n", bit_changed, byte_changed, shmem_info_p->adsp_changed_index[byte_changed]);

#ifdef SHMEM_DEBUG
	if(param_type(param)==PARAM_TYPE_INT32)
	{PX4_INFO("Set value %d for param %s to shmem, set adsp index %d:%d\n", value.i, param_name(param), byte_changed, bit_changed);}
	else if(param_type(param)==PARAM_TYPE_FLOAT)
	{PX4_INFO("Set value %f for param %s to shmem, set adsp index %d:%d\n", value.f, param_name(param), byte_changed, bit_changed);}
#endif

	release_shmem_lock();
	
} 

static void update_index_from_shmem(void)
{
	unsigned int i;

	if(get_shmem_lock()!=0) {
		PX4_ERR("Could not get shmem lock\n");
		return;
	}			

	//PX4_INFO("Updating index from shmem\n");

	for(i=0;i<MAX_SHMEM_PARAMS/8+1;i++)
		krait_changed_index[i]=shmem_info_p->krait_changed_index[i];

	release_shmem_lock();
}


static void update_value_from_shmem(param_t param, union param_value_u *value)
{
	unsigned int byte_changed, bit_changed;

	if(get_shmem_lock()!=0) {
		PX4_ERR("Could not get shmem lock\n");
		return;
	}			

	*value = shmem_info_p->params_val[param];

	/*also clear the index since we are holding the lock*/
	byte_changed = param/8;
	bit_changed = 1 << param%8;
	shmem_info_p->krait_changed_index[byte_changed] &= ~bit_changed; 

	release_shmem_lock();

#ifdef SHMEM_DEBUG
	if(param_type(param)==PARAM_TYPE_INT32)
	{PX4_INFO("Got value %d for param %s from shmem, cleared krait index %d:%d\n", value->i, param_name(param), byte_changed, bit_changed);}
	else if(param_type(param)==PARAM_TYPE_FLOAT)
	{PX4_INFO("Got value %f for param %s from shmem, cleared krait index %d:%d\n", value->f, param_name(param), byte_changed, bit_changed);}
#endif
}

int update_from_shmem(param_t param, union param_value_u *value)
{
	unsigned int byte_changed, bit_changed;
	unsigned int retval = 0;

	if(!handle_in_range(param) || value==NULL)
		return retval;

        update_from_shmem_current_time = hrt_absolute_time();
        if((update_from_shmem_current_time - update_from_shmem_prev_time) > 1000000) //update every 1 second
	{
		update_from_shmem_prev_time = update_from_shmem_current_time;
		update_index_from_shmem();
	}

	byte_changed = param/8;
	bit_changed = 1 << param%8;

	if(krait_changed_index[byte_changed] & bit_changed)
	{
		update_value_from_shmem(param, value);
		krait_changed_index[byte_changed] &= ~bit_changed; 
		retval = 1;
	}
	//else {PX4_INFO("no change to param %s\n", param_name(param));}

	//PX4_INFO("%s %d bit on krait changed index[%d]\n", (retval)?"cleared":"unchanged", bit_changed, byte_changed);

	return retval;
}