subsys/net/lib/lwm2m/ipso_timer.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2019 Foundries.io
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 /*
  * Source material for IPSO Timer object (3340):
  * http://www.openmobilealliance.org/tech/profiles/lwm2m/3340.xml
  */

 #define LOG_MODULE_NAME net_ipso_timer
 #define LOG_LEVEL CONFIG_LWM2M_LOG_LEVEL

 #include <logging/log.h>
 LOG_MODULE_REGISTER(LOG_MODULE_NAME);

 #include <stdint.h>
 #include <init.h>

 #include "lwm2m_object.h"
 #include "lwm2m_engine.h"

 /* Server resource IDs */
 #define TIMER_DELAY_DURATION_ID		5521
 #define TIMER_REMAINING_TIME_ID		5538
 #define TIMER_MINIMUM_OFF_TIME_ID	5525
 #define TIMER_TRIGGER_ID		5523
 #define TIMER_ON_OFF_ID			5850
 #define TIMER_DIGITAL_INPUT_COUNTER_ID	5501
 #define TIMER_CUMULATIVE_TIME_ID	5544
 #define TIMER_DIGITAL_STATE_ID		5543
 #define TIMER_COUNTER_ID		5534
 #define TIMER_MODE_ID			5526
 #define TIMER_APPLICATION_TYPE_ID	5750

 #define TIMER_MAX_ID		11

 #define MAX_INSTANCE_COUNT	CONFIG_LWM2M_IPSO_TIMER_INSTANCE_COUNT

 /*
  * Calculate resource instances as follows:
  * start with TIMER_MAX_ID
  * subtract EXEC resources (1)
  */
 #define RESOURCE_INSTANCE_COUNT	(TIMER_MAX_ID - 1)

 enum ipso_timer_mode {
 	TIMER_MODE_OFF = 0,
 	TIMER_MODE_ONE_SHOT,
 	TIMER_MODE_INTERVAL,		/* TODO */
 	TIMER_MODE_DELAY_ON_PICKUP,	/* TODO */
 	TIMER_MODE_DELAY_ON_DROPOUT,	/* TODO */
 };

 /* resource state */
 struct ipso_timer_data {
 	float64_value_t delay_duration;
 	float64_value_t remaining_time;
 	float64_value_t min_off_time;
 	float64_value_t cumulative_time;

 	u64_t trigger_offset;
 	u32_t trigger_counter;
 	u32_t cumulative_time_ms;

 	struct k_delayed_work timer_work;

 	u16_t obj_inst_id;
 	u8_t timer_mode;
 	bool enabled;
 	bool active;
 };

 static struct ipso_timer_data timer_data[MAX_INSTANCE_COUNT];

 static struct lwm2m_engine_obj timer;
 static struct lwm2m_engine_obj_field fields[] = {
 	OBJ_FIELD_DATA(TIMER_DELAY_DURATION_ID, RW, FLOAT64),
 	OBJ_FIELD_DATA(TIMER_REMAINING_TIME_ID, R_OPT, FLOAT64),
 	OBJ_FIELD_DATA(TIMER_MINIMUM_OFF_TIME_ID, RW_OPT, FLOAT64),
 	OBJ_FIELD_EXECUTE_OPT(TIMER_TRIGGER_ID),
 	OBJ_FIELD_DATA(TIMER_ON_OFF_ID, RW_OPT, BOOL),
 	OBJ_FIELD_DATA(TIMER_DIGITAL_INPUT_COUNTER_ID, RW_OPT, U32), /* TODO */
 	OBJ_FIELD_DATA(TIMER_CUMULATIVE_TIME_ID, RW_OPT, FLOAT64),
 	OBJ_FIELD_DATA(TIMER_DIGITAL_STATE_ID, R_OPT, BOOL),
 	OBJ_FIELD_DATA(TIMER_COUNTER_ID, R_OPT, U32),
 	OBJ_FIELD_DATA(TIMER_MODE_ID, RW_OPT, U8),
 	OBJ_FIELD_DATA(TIMER_APPLICATION_TYPE_ID, RW_OPT, STRING),
 };

 static struct lwm2m_engine_obj_inst inst[MAX_INSTANCE_COUNT];
 static struct lwm2m_engine_res res[MAX_INSTANCE_COUNT][TIMER_MAX_ID];
 static struct lwm2m_engine_res_inst
 		res_inst[MAX_INSTANCE_COUNT][RESOURCE_INSTANCE_COUNT];

 static int ms2float(u32_t ms, float64_value_t *f)
 {
 	f->val1 = ms / MSEC_PER_SEC;
 	f->val2 = (ms % MSEC_PER_SEC) * (LWM2M_FLOAT64_DEC_MAX / MSEC_PER_SEC);

 	return 0;
 }

 static int float2ms(float64_value_t *f, u32_t *ms)
 {
 	*ms = f->val1 * MSEC_PER_SEC;
 	*ms += f->val2 / (LWM2M_FLOAT64_DEC_MAX / MSEC_PER_SEC);

 	return 0;
 }

 static int get_timer_index(u16_t obj_inst_id)
 {
 	int i, ret = -ENOENT;

 	for (i = 0; i < MAX_INSTANCE_COUNT; i++) {
 		if (!inst[i].obj || inst[i].obj_inst_id != obj_inst_id) {
 			continue;
 		}

 		ret = i;
 		break;
 	}

 	return ret;
 }

 static int start_timer(struct ipso_timer_data *timer)
 {
 	u32_t temp = 0U;
 	char path[MAX_RESOURCE_LEN];

 	/* make sure timer is enabled and not already active */
 	if (timer->timer_mode == TIMER_MODE_OFF || timer->active ||
 	    !timer->enabled) {
 		return -EINVAL;
 	}

 	/* check min off time from last trigger_offset */
 	float2ms(&timer->min_off_time, &temp);
 	if (k_uptime_get() < timer->trigger_offset + temp) {
 		return -EINVAL;
 	}

 	/* TODO: check delay_duration > 0 ? other modes can it be 0? */

 	timer->trigger_offset = k_uptime_get();
 	timer->trigger_counter += 1U;

 	snprintk(path, MAX_RESOURCE_LEN, "%d/%u/%d", IPSO_OBJECT_TIMER_ID,
 		 timer->obj_inst_id, TIMER_DIGITAL_STATE_ID);
 	lwm2m_engine_set_bool(path, true);

 	float2ms(&timer->delay_duration, &temp);
 	k_delayed_work_submit(&timer->timer_work, temp);

 	return 0;
 }

 static int stop_timer(struct ipso_timer_data *timer, bool cancel)
 {
 	char path[MAX_RESOURCE_LEN];

 	/* make sure timer is active */
 	if (!timer->active) {
 		return -EINVAL;
 	}

 	timer->cumulative_time_ms += k_uptime_get() - timer->trigger_offset;
 	snprintk(path, MAX_RESOURCE_LEN, "%d/%u/%d", IPSO_OBJECT_TIMER_ID,
 		 timer->obj_inst_id, TIMER_DIGITAL_STATE_ID);
 	lwm2m_engine_set_bool(path, false);

 	if (cancel) {
 		k_delayed_work_cancel(&timer->timer_work);
 	}

 	return 0;
 }

 static void *remaining_time_read_cb(u16_t obj_inst_id,
 				    u16_t res_id, u16_t res_inst_id,
 				    size_t *data_len)
 {
 	u32_t temp = 0U;
 	int i;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return NULL;
 	}

 	if (timer_data[i].active) {
 		float2ms(&timer_data[i].delay_duration, &temp);
 		temp -= (k_uptime_get() - timer_data[i].trigger_offset);
 		ms2float(temp, &timer_data[i].remaining_time);
 	} else {
 		timer_data[i].remaining_time.val1 = 0;
 		timer_data[i].remaining_time.val2 = 0;
 	}

 	*data_len = sizeof(timer_data[i].remaining_time);
 	return &timer_data[i].remaining_time;
 }

 static void *cumulative_time_read_cb(u16_t obj_inst_id,
 				     u16_t res_id, u16_t res_inst_id,
 				     size_t *data_len)
 {
 	int i;
 	u32_t temp;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return NULL;
 	}

 	temp = timer_data[i].cumulative_time_ms;
 	if (timer_data[i].active) {
 		temp += k_uptime_get() - timer_data[i].trigger_offset;
 	}

 	ms2float(temp, &timer_data[i].cumulative_time);

 	*data_len = sizeof(timer_data[i].cumulative_time);
 	return &timer_data[i].cumulative_time;
 }

 static int cumulative_time_post_write_cb(u16_t obj_inst_id,
 					 u16_t res_id, u16_t res_inst_id,
 					 u8_t *data, u16_t data_len,
 					 bool last_block, size_t total_size)
 {
 	int i;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return i;
 	}

 	timer_data[i].cumulative_time_ms = 0U;
 	return 0;
 }

 static int enabled_post_write_cb(u16_t obj_inst_id,
 				 u16_t res_id, u16_t res_inst_id,
 				 u8_t *data, u16_t data_len,
 				 bool last_block, size_t total_size)
 {
 	int i;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return i;
 	}

 	/* check if timer is active and move to disabled state */
 	if (!timer_data[i].enabled && timer_data[i].active) {
 		return stop_timer(&timer_data[i], true);
 	}

 	return 0;
 }

 static int trigger_counter_post_write_cb(u16_t obj_inst_id,
 					 u16_t res_id, u16_t res_inst_id,
 					 u8_t *data, u16_t data_len,
 					 bool last_block, size_t total_size)
 {
 	int i;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return i;
 	}

 	timer_data[i].trigger_counter = 0U;
 	return 0;
 }

 static void timer_work_cb(struct k_work *work)
 {
 	struct ipso_timer_data *timer = CONTAINER_OF(work,
 						     struct ipso_timer_data,
 						     timer_work);
 	stop_timer(timer, false);
 }

 static int timer_trigger_cb(u16_t obj_inst_id)
 {
 	int i;

 	i = get_timer_index(obj_inst_id);
 	if (i < 0) {
 		return i;
 	}

 	return start_timer(&timer_data[i]);
 }

 static struct lwm2m_engine_obj_inst *timer_create(u16_t obj_inst_id)
 {
 	int index, avail = -1, i = 0, j = 0;

 	/* Check that there is no other instance with this ID */
 	for (index = 0; index < MAX_INSTANCE_COUNT; index++) {
 		if (inst[index].obj && inst[index].obj_inst_id == obj_inst_id) {
 			LOG_ERR("Can not create instance - "
 				"already existing: %u", obj_inst_id);
 			return NULL;
 		}

 		/* Save first available slot index */
 		if (avail < 0 && !inst[index].obj) {
 			avail = index;
 		}
 	}

 	if (avail < 0) {
 		LOG_ERR("Can not create instance - no more room: %u",
 			obj_inst_id);
 		return NULL;
 	}

 	/* Set default values */
 	(void)memset(&timer_data[avail], 0, sizeof(timer_data[avail]));
 	k_delayed_work_init(&timer_data[avail].timer_work, timer_work_cb);
 	timer_data[avail].delay_duration.val1 = 5; /* 5 seconds */
 	timer_data[avail].enabled = true;
 	timer_data[avail].timer_mode = TIMER_MODE_ONE_SHOT;
 	timer_data[avail].obj_inst_id = obj_inst_id;

 	(void)memset(res[avail], 0,
 		     sizeof(res[avail][0]) * ARRAY_SIZE(res[avail]));
 	init_res_instance(res_inst[avail], ARRAY_SIZE(res_inst[avail]));

 	/* initialize instance resource data */
 	INIT_OBJ_RES_DATA(TIMER_DELAY_DURATION_ID, res[avail], i,
 			  res_inst[avail], j, &timer_data[avail].delay_duration,
 			  sizeof(timer_data[avail].delay_duration));
 	INIT_OBJ_RES(TIMER_REMAINING_TIME_ID, res[avail], i,
 		     res_inst[avail], j, 1, true,
 		     &timer_data[avail].remaining_time,
 		     sizeof(timer_data[avail].remaining_time),
 		     remaining_time_read_cb, NULL, NULL, NULL);
 	INIT_OBJ_RES_DATA(TIMER_MINIMUM_OFF_TIME_ID, res[avail], i,
 			  res_inst[avail], j, &timer_data[avail].min_off_time,
 			  sizeof(timer_data[avail].min_off_time));
 	INIT_OBJ_RES_EXECUTE(TIMER_TRIGGER_ID, res[avail], i,
 			     timer_trigger_cb);
 	INIT_OBJ_RES(TIMER_ON_OFF_ID, res[avail], i,
 		     res_inst[avail], j, 1, true,
 		     &timer_data[avail].enabled,
 		     sizeof(timer_data[avail].enabled),
 		     NULL, NULL, enabled_post_write_cb, NULL);
 	INIT_OBJ_RES(TIMER_CUMULATIVE_TIME_ID, res[avail], i,
 		     res_inst[avail], j, 1, true,
 		     &timer_data[avail].cumulative_time,
 		     sizeof(timer_data[avail].cumulative_time),
 		     cumulative_time_read_cb, NULL,
 		     cumulative_time_post_write_cb, NULL);
 	INIT_OBJ_RES_DATA(TIMER_DIGITAL_STATE_ID, res[avail], i,
 			  res_inst[avail], j, &timer_data[avail].active,
 			  sizeof(timer_data[avail].active));
 	INIT_OBJ_RES(TIMER_COUNTER_ID, res[avail], i,
 		     res_inst[avail], j, 1, true,
 		     &timer_data[avail].trigger_counter,
 		     sizeof(timer_data[avail].trigger_counter),
 		     NULL, NULL, trigger_counter_post_write_cb, NULL);
 	INIT_OBJ_RES_DATA(TIMER_MODE_ID, res[avail], i, res_inst[avail], j,
 			  &timer_data[avail].timer_mode,
 			  sizeof(timer_data[avail].timer_mode));
 	INIT_OBJ_RES_OPTDATA(TIMER_APPLICATION_TYPE_ID, res[avail], i,
 			     res_inst[avail], j);

 	inst[avail].resources = res[avail];
 	inst[avail].resource_count = i;

 	LOG_DBG("Create IPSO Timer instance: %d", obj_inst_id);

 	return &inst[avail];
 }

 static int ipso_timer_init(struct device *dev)
 {
 	timer.obj_id = IPSO_OBJECT_TIMER_ID;
 	timer.fields = fields;
 	timer.field_count = ARRAY_SIZE(fields);
 	timer.max_instance_count = MAX_INSTANCE_COUNT;
 	timer.create_cb = timer_create;
 	lwm2m_register_obj(&timer);

 	return 0;
 }

 SYS_INIT(ipso_timer_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
	/*
	* Copyright (c) 2019 Foundries.io
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	/*
	* Source material for IPSO Timer object (3340):
	* http://www.openmobilealliance.org/tech/profiles/lwm2m/3340.xml
	*/

	#define LOG_MODULE_NAME net_ipso_timer
	#define LOG_LEVEL CONFIG_LWM2M_LOG_LEVEL

	#include <logging/log.h>
	LOG_MODULE_REGISTER(LOG_MODULE_NAME);

	#include <stdint.h>
	#include <init.h>

	#include "lwm2m_object.h"
	#include "lwm2m_engine.h"

	/* Server resource IDs */
	#define TIMER_DELAY_DURATION_ID 5521
	#define TIMER_REMAINING_TIME_ID 5538
	#define TIMER_MINIMUM_OFF_TIME_ID 5525
	#define TIMER_TRIGGER_ID 5523
	#define TIMER_ON_OFF_ID 5850
	#define TIMER_DIGITAL_INPUT_COUNTER_ID 5501
	#define TIMER_CUMULATIVE_TIME_ID 5544
	#define TIMER_DIGITAL_STATE_ID 5543
	#define TIMER_COUNTER_ID 5534
	#define TIMER_MODE_ID 5526
	#define TIMER_APPLICATION_TYPE_ID 5750

	#define TIMER_MAX_ID 11

	#define MAX_INSTANCE_COUNT CONFIG_LWM2M_IPSO_TIMER_INSTANCE_COUNT

	/*
	* Calculate resource instances as follows:
	* start with TIMER_MAX_ID
	* subtract EXEC resources (1)
	*/
	#define RESOURCE_INSTANCE_COUNT (TIMER_MAX_ID - 1)

	enum ipso_timer_mode {
	TIMER_MODE_OFF = 0,
	TIMER_MODE_ONE_SHOT,
	TIMER_MODE_INTERVAL, /* TODO */
	TIMER_MODE_DELAY_ON_PICKUP, /* TODO */
	TIMER_MODE_DELAY_ON_DROPOUT, /* TODO */
	};

	/* resource state */
	struct ipso_timer_data {
	float64_value_t delay_duration;
	float64_value_t remaining_time;
	float64_value_t min_off_time;
	float64_value_t cumulative_time;

	u64_t trigger_offset;
	u32_t trigger_counter;
	u32_t cumulative_time_ms;

	struct k_delayed_work timer_work;

	u16_t obj_inst_id;
	u8_t timer_mode;
	bool enabled;
	bool active;
	};

	static struct ipso_timer_data timer_data[MAX_INSTANCE_COUNT];

	static struct lwm2m_engine_obj timer;
	static struct lwm2m_engine_obj_field fields[] = {
	OBJ_FIELD_DATA(TIMER_DELAY_DURATION_ID, RW, FLOAT64),
	OBJ_FIELD_DATA(TIMER_REMAINING_TIME_ID, R_OPT, FLOAT64),
	OBJ_FIELD_DATA(TIMER_MINIMUM_OFF_TIME_ID, RW_OPT, FLOAT64),
	OBJ_FIELD_EXECUTE_OPT(TIMER_TRIGGER_ID),
	OBJ_FIELD_DATA(TIMER_ON_OFF_ID, RW_OPT, BOOL),
	OBJ_FIELD_DATA(TIMER_DIGITAL_INPUT_COUNTER_ID, RW_OPT, U32), /* TODO */
	OBJ_FIELD_DATA(TIMER_CUMULATIVE_TIME_ID, RW_OPT, FLOAT64),
	OBJ_FIELD_DATA(TIMER_DIGITAL_STATE_ID, R_OPT, BOOL),
	OBJ_FIELD_DATA(TIMER_COUNTER_ID, R_OPT, U32),
	OBJ_FIELD_DATA(TIMER_MODE_ID, RW_OPT, U8),
	OBJ_FIELD_DATA(TIMER_APPLICATION_TYPE_ID, RW_OPT, STRING),
	};

	static struct lwm2m_engine_obj_inst inst[MAX_INSTANCE_COUNT];
	static struct lwm2m_engine_res res[MAX_INSTANCE_COUNT][TIMER_MAX_ID];
	static struct lwm2m_engine_res_inst
	res_inst[MAX_INSTANCE_COUNT][RESOURCE_INSTANCE_COUNT];

	static int ms2float(u32_t ms, float64_value_t *f)
	{
	f->val1 = ms / MSEC_PER_SEC;
	f->val2 = (ms % MSEC_PER_SEC) * (LWM2M_FLOAT64_DEC_MAX / MSEC_PER_SEC);

	return 0;
	}

	static int float2ms(float64_value_t f, u32_t ms)
	{
	ms = f->val1 MSEC_PER_SEC;
	*ms += f->val2 / (LWM2M_FLOAT64_DEC_MAX / MSEC_PER_SEC);

	return 0;
	}

	static int get_timer_index(u16_t obj_inst_id)
	{
	int i, ret = -ENOENT;

	for (i = 0; i < MAX_INSTANCE_COUNT; i++) {
	if (!inst[i].obj \|\| inst[i].obj_inst_id != obj_inst_id) {
	continue;
	}

	ret = i;
	break;
	}

	return ret;
	}

	static int start_timer(struct ipso_timer_data *timer)
	{
	u32_t temp = 0U;
	char path[MAX_RESOURCE_LEN];

	/* make sure timer is enabled and not already active */
	if (timer->timer_mode == TIMER_MODE_OFF \|\| timer->active \|\|
	!timer->enabled) {
	return -EINVAL;
	}

	/* check min off time from last trigger_offset */
	float2ms(&timer->min_off_time, &temp);
	if (k_uptime_get() < timer->trigger_offset + temp) {
	return -EINVAL;
	}

	/* TODO: check delay_duration > 0 ? other modes can it be 0? */

	timer->trigger_offset = k_uptime_get();
	timer->trigger_counter += 1U;

	snprintk(path, MAX_RESOURCE_LEN, "%d/%u/%d", IPSO_OBJECT_TIMER_ID,
	timer->obj_inst_id, TIMER_DIGITAL_STATE_ID);
	lwm2m_engine_set_bool(path, true);

	float2ms(&timer->delay_duration, &temp);
	k_delayed_work_submit(&timer->timer_work, temp);

	return 0;
	}

	static int stop_timer(struct ipso_timer_data *timer, bool cancel)
	{
	char path[MAX_RESOURCE_LEN];

	/* make sure timer is active */
	if (!timer->active) {
	return -EINVAL;
	}

	timer->cumulative_time_ms += k_uptime_get() - timer->trigger_offset;
	snprintk(path, MAX_RESOURCE_LEN, "%d/%u/%d", IPSO_OBJECT_TIMER_ID,
	timer->obj_inst_id, TIMER_DIGITAL_STATE_ID);
	lwm2m_engine_set_bool(path, false);

	if (cancel) {
	k_delayed_work_cancel(&timer->timer_work);
	}

	return 0;
	}

	static void *remaining_time_read_cb(u16_t obj_inst_id,
	u16_t res_id, u16_t res_inst_id,
	size_t *data_len)
	{
	u32_t temp = 0U;
	int i;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return NULL;
	}

	if (timer_data[i].active) {
	float2ms(&timer_data[i].delay_duration, &temp);
	temp -= (k_uptime_get() - timer_data[i].trigger_offset);
	ms2float(temp, &timer_data[i].remaining_time);
	} else {
	timer_data[i].remaining_time.val1 = 0;
	timer_data[i].remaining_time.val2 = 0;
	}

	*data_len = sizeof(timer_data[i].remaining_time);
	return &timer_data[i].remaining_time;
	}

	static void *cumulative_time_read_cb(u16_t obj_inst_id,
	u16_t res_id, u16_t res_inst_id,
	size_t *data_len)
	{
	int i;
	u32_t temp;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return NULL;
	}

	temp = timer_data[i].cumulative_time_ms;
	if (timer_data[i].active) {
	temp += k_uptime_get() - timer_data[i].trigger_offset;
	}

	ms2float(temp, &timer_data[i].cumulative_time);

	*data_len = sizeof(timer_data[i].cumulative_time);
	return &timer_data[i].cumulative_time;
	}

	static int cumulative_time_post_write_cb(u16_t obj_inst_id,
	u16_t res_id, u16_t res_inst_id,
	u8_t *data, u16_t data_len,
	bool last_block, size_t total_size)
	{
	int i;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return i;
	}

	timer_data[i].cumulative_time_ms = 0U;
	return 0;
	}

	static int enabled_post_write_cb(u16_t obj_inst_id,
	u16_t res_id, u16_t res_inst_id,
	u8_t *data, u16_t data_len,
	bool last_block, size_t total_size)
	{
	int i;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return i;
	}

	/* check if timer is active and move to disabled state */
	if (!timer_data[i].enabled && timer_data[i].active) {
	return stop_timer(&timer_data[i], true);
	}

	return 0;
	}

	static int trigger_counter_post_write_cb(u16_t obj_inst_id,
	u16_t res_id, u16_t res_inst_id,
	u8_t *data, u16_t data_len,
	bool last_block, size_t total_size)
	{
	int i;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return i;
	}

	timer_data[i].trigger_counter = 0U;
	return 0;
	}

	static void timer_work_cb(struct k_work *work)
	{
	struct ipso_timer_data *timer = CONTAINER_OF(work,
	struct ipso_timer_data,
	timer_work);
	stop_timer(timer, false);
	}

	static int timer_trigger_cb(u16_t obj_inst_id)
	{
	int i;

	i = get_timer_index(obj_inst_id);
	if (i < 0) {
	return i;
	}

	return start_timer(&timer_data[i]);
	}

	static struct lwm2m_engine_obj_inst *timer_create(u16_t obj_inst_id)
	{
	int index, avail = -1, i = 0, j = 0;

	/* Check that there is no other instance with this ID */
	for (index = 0; index < MAX_INSTANCE_COUNT; index++) {
	if (inst[index].obj && inst[index].obj_inst_id == obj_inst_id) {
	LOG_ERR("Can not create instance - "
	"already existing: %u", obj_inst_id);
	return NULL;
	}

	/* Save first available slot index */
	if (avail < 0 && !inst[index].obj) {
	avail = index;
	}
	}

	if (avail < 0) {
	LOG_ERR("Can not create instance - no more room: %u",
	obj_inst_id);
	return NULL;
	}

	/* Set default values */
	(void)memset(&timer_data[avail], 0, sizeof(timer_data[avail]));
	k_delayed_work_init(&timer_data[avail].timer_work, timer_work_cb);
	timer_data[avail].delay_duration.val1 = 5; /* 5 seconds */
	timer_data[avail].enabled = true;
	timer_data[avail].timer_mode = TIMER_MODE_ONE_SHOT;
	timer_data[avail].obj_inst_id = obj_inst_id;

	(void)memset(res[avail], 0,
	sizeof(res[avail][0]) * ARRAY_SIZE(res[avail]));
	init_res_instance(res_inst[avail], ARRAY_SIZE(res_inst[avail]));

	/* initialize instance resource data */
	INIT_OBJ_RES_DATA(TIMER_DELAY_DURATION_ID, res[avail], i,
	res_inst[avail], j, &timer_data[avail].delay_duration,
	sizeof(timer_data[avail].delay_duration));
	INIT_OBJ_RES(TIMER_REMAINING_TIME_ID, res[avail], i,
	res_inst[avail], j, 1, true,
	&timer_data[avail].remaining_time,
	sizeof(timer_data[avail].remaining_time),
	remaining_time_read_cb, NULL, NULL, NULL);
	INIT_OBJ_RES_DATA(TIMER_MINIMUM_OFF_TIME_ID, res[avail], i,
	res_inst[avail], j, &timer_data[avail].min_off_time,
	sizeof(timer_data[avail].min_off_time));
	INIT_OBJ_RES_EXECUTE(TIMER_TRIGGER_ID, res[avail], i,
	timer_trigger_cb);
	INIT_OBJ_RES(TIMER_ON_OFF_ID, res[avail], i,
	res_inst[avail], j, 1, true,
	&timer_data[avail].enabled,
	sizeof(timer_data[avail].enabled),
	NULL, NULL, enabled_post_write_cb, NULL);
	INIT_OBJ_RES(TIMER_CUMULATIVE_TIME_ID, res[avail], i,
	res_inst[avail], j, 1, true,
	&timer_data[avail].cumulative_time,
	sizeof(timer_data[avail].cumulative_time),
	cumulative_time_read_cb, NULL,
	cumulative_time_post_write_cb, NULL);
	INIT_OBJ_RES_DATA(TIMER_DIGITAL_STATE_ID, res[avail], i,
	res_inst[avail], j, &timer_data[avail].active,
	sizeof(timer_data[avail].active));
	INIT_OBJ_RES(TIMER_COUNTER_ID, res[avail], i,
	res_inst[avail], j, 1, true,
	&timer_data[avail].trigger_counter,
	sizeof(timer_data[avail].trigger_counter),
	NULL, NULL, trigger_counter_post_write_cb, NULL);
	INIT_OBJ_RES_DATA(TIMER_MODE_ID, res[avail], i, res_inst[avail], j,
	&timer_data[avail].timer_mode,
	sizeof(timer_data[avail].timer_mode));
	INIT_OBJ_RES_OPTDATA(TIMER_APPLICATION_TYPE_ID, res[avail], i,
	res_inst[avail], j);

	inst[avail].resources = res[avail];
	inst[avail].resource_count = i;

	LOG_DBG("Create IPSO Timer instance: %d", obj_inst_id);

	return &inst[avail];
	}

	static int ipso_timer_init(struct device *dev)
	{
	timer.obj_id = IPSO_OBJECT_TIMER_ID;
	timer.fields = fields;
	timer.field_count = ARRAY_SIZE(fields);
	timer.max_instance_count = MAX_INSTANCE_COUNT;
	timer.create_cb = timer_create;
	lwm2m_register_obj(&timer);

	return 0;
	}

	SYS_INIT(ipso_timer_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);