zephyr/include/adc.h

168 lines
4.3 KiB
C

/* adc.h - ADC public API */
/*
* Copyright (c) 2015 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 ADC public API header file.
*/
#ifndef __INCLUDE_ADC_H__
#define __INCLUDE_ADC_H__
#include <stdint.h>
#include <device.h>
/**
* Callback type.
* ADC_CB_DONE means sampling went fine and is over
* ADC_CB_ERROR means an error occurred
*/
enum adc_callback_type {
ADC_CB_DONE = 0,
ADC_CB_ERROR = 1
};
/** This type defines an pointer to an ADC callback routine */
typedef void (*adc_callback_t)(struct device *dev,
enum adc_callback_type cb_type);
/**
* @brief Sequence entry
*
* This structure defines a sequence entry used by the ADC driver
* to define a sample from a specific channel.
*/
struct adc_seq_entry {
/** Clock ticks delay before sampling the ADC */
int32_t sampling_delay;
/** Channel ID that should be sampled from the ADC */
uint8_t channel_id;
/** Buffer pointer where to write the sample */
uint8_t *buffer;
/** Length of the sampling buffer */
uint32_t buffer_length;
};
/**
* @brief Sequence table
*
* This structure represents a list of sequence entries that are
* used by the ADC driver to execute a sequence of samplings.
*/
struct adc_seq_table {
/* Pointer to a sequence entry array */
struct adc_seq_entry *entries;
/* Number of entries in the sequence entry array */
uint8_t num_entries;
};
/**
* @brief ADC driver API
*
* This structure holds all API function pointers.
*/
struct adc_driver_api {
/** Pointer to the enable routine */
void (*enable)(struct device *dev);
/** Pointer to the disable routine */
void (*disable)(struct device *dev);
/** Pointer to the set_cb routine */
void (*set_callback)(struct device *dev, adc_callback_t cb);
/** Pointer to the read routine */
int (*read)(struct device *dev, struct adc_seq_table *seq_table);
};
/**
* @brief Enable ADC hardware
*
* This routine enables the ADC hardware block for data sampling for the
* specified device.
*
* @param dev Pointer to the device structure for the driver instance
*
* @return N/A
*/
static inline void adc_enable(struct device *dev)
{
struct adc_driver_api *api;
api = (struct adc_driver_api *)dev->driver_api;
api->enable(dev);
}
/**
* @brief Disable ADC hardware
*
* This routine disables the ADC hardware block for data sampling for the
* specified device.
*
* @param dev Pointer to the device structure for the driver instance
*
* @return N/A
*/
static inline void adc_disable(struct device *dev)
{
struct adc_driver_api *api;
api = (struct adc_driver_api *)dev->driver_api;
api->disable(dev);
}
/**
* @brief Set callback routine
*
* This routine sets the callback routine that will be called by the driver
* every time that sample data is available for consumption or an error is
* signaled.
*
* @param dev Pointer to the device structure for the driver instance
* @param cb Pointer to the function that will be set as callback.
*
* @return N/A
*/
static inline void adc_set_callback(struct device *dev, adc_callback_t cb)
{
struct adc_driver_api *api;
api = (struct adc_driver_api *)dev->driver_api;
api->set_callback(dev, cb);
}
/**
* @brief Set a read request.
*
* This routine sends a read/sampling request to the ADC hardware block.
* The read request is described by a sequence table. The read data is not
* available for consumption until it is indicated by a callback.
*
* @param dev Pointer to the device structure for the driver instance
* @param seq_tbl Pointer to the structure that represents the sequence table
*
* @return Returns DEV_OK on success, or else otherwise.
*/
static inline int adc_read(struct device *dev, struct adc_seq_table *seq_table)
{
struct adc_driver_api *api;
api = (struct adc_driver_api *)dev->driver_api;
return api->read(dev, seq_table);
}
#endif /* __INCLUDE_ADC_H__ */