zephyr/include/counter.h

158 lines
4.2 KiB
C

/*
* Copyright (c) 2016 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief Public API for counter and timer drivers
*/
#ifndef __COUNTER_H__
#define __COUNTER_H__
/**
* @brief COUNTER Interface
* @defgroup counter_interface COUNTER Interface
* @ingroup io_interfaces
* @{
*/
#include <stdint.h>
#include <stddef.h>
#include <device.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef void (*counter_callback_t)(struct device *dev, void *user_data);
typedef int (*counter_api_start)(struct device *dev);
typedef int (*counter_api_stop)(struct device *dev);
typedef uint32_t (*counter_api_read)(void);
typedef int (*counter_api_set_alarm)(struct device *dev,
counter_callback_t callback,
uint32_t count, void *user_data);
typedef uint32_t (*counter_api_get_pending_int)(struct device *dev);
struct counter_driver_api {
counter_api_start start;
counter_api_stop stop;
counter_api_read read;
counter_api_set_alarm set_alarm;
counter_api_get_pending_int get_pending_int;
};
/**
* @brief Start counter device in free running mode.
*
* Start the counter device. If the device is a 'countup' counter, the
* counter initial value is set to zero. If it is a 'countdown' counter,
* the initial value is set to the maximum value supported by the device.
*
* @param dev Pointer to the device structure for the driver instance.
*
* @retval 0 If successful.
* @retval Negative errno code if failure.
*/
static inline int counter_start(struct device *dev)
{
const struct counter_driver_api *api = dev->driver_api;
return api->start(dev);
}
/**
* @brief Stop counter device.
* @param dev Pointer to the device structure for the driver instance.
*
* @retval 0 If successful.
* @retval -ENODEV if the device doesn't support stopping the
* counter.
*/
static inline int counter_stop(struct device *dev)
{
const struct counter_driver_api *api = dev->driver_api;
return api->stop(dev);
}
/**
* @brief Read current counter value.
* @param dev Pointer to the device structure for the driver instance.
*
* @return 32-bit value
*/
static inline uint32_t counter_read(struct device *dev)
{
const struct counter_driver_api *api = dev->driver_api;
return api->read();
}
/**
* @brief Set an alarm.
* @param dev Pointer to the device structure for the driver instance.
* @param callback Pointer to the callback function. if this is NULL,
* this function unsets the alarm.
* @param count Number of counter ticks.
* @param user_data Pointer to user data.
*
* @retval 0 If successful.
* @retval -ENOTSUP if the counter was not started yet.
* @retval -ENODEV if the device doesn't support interrupt (e.g. free
* running counters).
* @retval Negative errno code if failure.
*/
static inline int counter_set_alarm(struct device *dev,
counter_callback_t callback,
uint32_t count, void *user_data)
{
const struct counter_driver_api *api = dev->driver_api;
return api->set_alarm(dev, callback, count, user_data);
}
/**
* @brief Function to get pending interrupts
*
* The purpose of this function is to return the interrupt
* status register for the device.
* This is especially useful when waking up from
* low power states to check the wake up source.
*
* @param dev Pointer to the device structure for the driver instance.
*
* @retval 1 if the counter interrupt is pending.
* @retval 0 if no counter interrupt is pending.
*/
static inline int counter_get_pending_int(struct device *dev)
{
struct counter_driver_api *api;
api = (struct counter_driver_api *)dev->driver_api;
return api->get_pending_int(dev);
}
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* __COUNTER_H__ */