adc.h

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/*
 * Copyright (c) 2018 Nordic Semiconductor ASA
 * Copyright (c) 2015 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_DRIVERS_ADC_H_
#define ZEPHYR_INCLUDE_DRIVERS_ADC_H_
 
#include <device.h>
#include <dt-bindings/adc/adc.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
enum adc_gain {
        ADC_GAIN_1_6, 
        ADC_GAIN_1_5, 
        ADC_GAIN_1_4, 
        ADC_GAIN_1_3, 
        ADC_GAIN_1_2, 
        ADC_GAIN_2_3, 
        ADC_GAIN_1,   
        ADC_GAIN_2,   
        ADC_GAIN_3,   
        ADC_GAIN_4,   
        ADC_GAIN_6,   
        ADC_GAIN_8,   
        ADC_GAIN_12,  
        ADC_GAIN_16,  
        ADC_GAIN_24,  
        ADC_GAIN_32,  
        ADC_GAIN_64,  
        ADC_GAIN_128, 
};
 
int adc_gain_invert(enum adc_gain gain,
                    int32_t *value);
 
enum adc_reference {
        ADC_REF_VDD_1,     
        ADC_REF_VDD_1_2,   
        ADC_REF_VDD_1_3,   
        ADC_REF_VDD_1_4,   
        ADC_REF_INTERNAL,  
        ADC_REF_EXTERNAL0, 
        ADC_REF_EXTERNAL1, 
};
 
struct adc_channel_cfg {
        enum adc_gain gain;
 
        enum adc_reference reference;
 
        uint16_t acquisition_time;
 
        uint8_t channel_id   : 5;
 
        uint8_t differential : 1;
 
#ifdef CONFIG_ADC_CONFIGURABLE_INPUTS
        uint8_t input_positive;
 
        uint8_t input_negative;
#endif /* CONFIG_ADC_CONFIGURABLE_INPUTS */
};
 
static inline int adc_raw_to_millivolts(int32_t ref_mv,
                                        enum adc_gain gain,
                                        uint8_t resolution,
                                        int32_t *valp)
{
        int32_t adc_mv = *valp * ref_mv;
        int ret = adc_gain_invert(gain, &adc_mv);
 
        if (ret == 0) {
                *valp = (adc_mv >> resolution);
        }
 
        return ret;
}
 
/* Forward declaration of the adc_sequence structure. */
struct adc_sequence;
 
enum adc_action {
        ADC_ACTION_CONTINUE = 0,
 
        ADC_ACTION_REPEAT,
 
        ADC_ACTION_FINISH,
};
 
typedef enum adc_action (*adc_sequence_callback)(const struct device *dev,
                                                 const struct adc_sequence *sequence,
                                                 uint16_t sampling_index);
 
struct adc_sequence_options {
        uint32_t interval_us;
 
        adc_sequence_callback callback;
 
        void *user_data;
 
        uint16_t extra_samplings;
};
 
struct adc_sequence {
        const struct adc_sequence_options *options;
 
        uint32_t channels;
 
        void *buffer;
 
        size_t buffer_size;
 
        uint8_t resolution;
 
        uint8_t oversampling;
 
        bool calibrate;
};
 
 
typedef int (*adc_api_channel_setup)(const struct device *dev,
                                     const struct adc_channel_cfg *channel_cfg);
 
typedef int (*adc_api_read)(const struct device *dev,
                            const struct adc_sequence *sequence);
 
typedef int (*adc_api_read_async)(const struct device *dev,
                                  const struct adc_sequence *sequence,
                                  struct k_poll_signal *async);
 
__subsystem struct adc_driver_api {
        adc_api_channel_setup channel_setup;
        adc_api_read          read;
#ifdef CONFIG_ADC_ASYNC
        adc_api_read_async    read_async;
#endif
        uint16_t ref_internal;  /* mV */
};
 
__syscall int adc_channel_setup(const struct device *dev,
                                const struct adc_channel_cfg *channel_cfg);
 
static inline int z_impl_adc_channel_setup(const struct device *dev,
                                           const struct adc_channel_cfg *channel_cfg)
{
        const struct adc_driver_api *api =
                                (const struct adc_driver_api *)dev->api;
 
        return api->channel_setup(dev, channel_cfg);
}
 
__syscall int adc_read(const struct device *dev,
                       const struct adc_sequence *sequence);
 
static inline int z_impl_adc_read(const struct device *dev,
                                  const struct adc_sequence *sequence)
{
        const struct adc_driver_api *api =
                                (const struct adc_driver_api *)dev->api;
 
        return api->read(dev, sequence);
}
 
__syscall int adc_read_async(const struct device *dev,
                             const struct adc_sequence *sequence,
                             struct k_poll_signal *async);
 
 
#ifdef CONFIG_ADC_ASYNC
static inline int z_impl_adc_read_async(const struct device *dev,
                                        const struct adc_sequence *sequence,
                                        struct k_poll_signal *async)
{
        const struct adc_driver_api *api =
                                (const struct adc_driver_api *)dev->api;
 
        return api->read_async(dev, sequence, async);
}
#endif /* CONFIG_ADC_ASYNC */
 
static inline uint16_t adc_ref_internal(const struct device *dev)
{
        const struct adc_driver_api *api =
                                (const struct adc_driver_api *)dev->api;
 
        return api->ref_internal;
}
 
#ifdef __cplusplus
}
#endif
 
#include <syscalls/adc.h>
 
#endif  /* ZEPHYR_INCLUDE_DRIVERS_ADC_H_ */