d83647dea6
ADC emulator is designed to be used in tests on native_posix board. It supports 1-16 bit resolution range and all GAINs from enum adc_gain. Reference voltages and number of emulated channels are set through dts. Using special API from drivers/adc/adc_emul.h it is possible to set constant voltage value returned by given ADC channel or set custom function which allows to simulate complex output. Also reference voltages can be changed in runtime using the API. The CL also includes: - Add adc definitions of ADC emulator in tests/drivers/adc/adc_api/src/test_adc.c for supporting test suites. - Add test for ADC emulator API in tests/drivers/adc/adc_emul/ Signed-off-by: Tomasz Michalec <tm@semihalf.com>
111 lines
3.1 KiB
C
111 lines
3.1 KiB
C
/**
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* @file
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*
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* @brief Backend API for emulated ADC
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*/
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/*
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* Copyright 2021 Google LLC
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_
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#define ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_
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#include <zephyr/types.h>
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#include <drivers/adc.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @brief Emulated ADC backend API
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* @defgroup adc_emul Emulated ADC
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* @ingroup adc_interface
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* @{
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*
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* Behaviour of emulated ADC is application-defined. As-such, each
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* application may
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*
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* - define a Device Tree overlay file to indicate the number of ADC
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* controllers as well as the number of channels for each controller
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* - set default reference voltages in Device Tree or using
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* @ref adc_emul_ref_voltage_set
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* - asynchronously call @ref adc_emul_const_value_set in order to set
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* constant mV value on emulated ADC input
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* - asynchronously call @ref adc_emul_value_func_set in order to assign
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* function which will be used to obtain voltage on emulated ADC input
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*
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* An example of an appropriate Device Tree overlay file is in
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* tests/drivers/adc/adc_api/boards/native_posix.overlay
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*
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* An example of using emulated ADC backend API is in the file
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* tests/drivers/adc/adc_emul/src/main.c
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*/
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/**
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* @brief Type definition of the function which is used to obtain ADC
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* mV input values
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*
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* @param dev Pointer to the device structure for the driver instance
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* @param chan ADC channel to sample
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* @param data User data which was passed on @ref adc_emul_value_func_set
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* @param result The result value which will be set as input for ADC @p chan
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*
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* @return 0 on success
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* @return other as error code which ends ADC context
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*/
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typedef int (*adc_emul_value_func)(const struct device *dev, unsigned int chan,
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void *data, uint32_t *result);
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/**
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* @brief Set constant mV value input for emulated ADC @p chan
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*
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* @param dev The emulated ADC device
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* @param chan The channel of ADC which input is assigned
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* @param value New voltage in mV to assign to @p chan input
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*
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* @return 0 on success
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* @return -EINVAL if an invalid argument is provided
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*/
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int adc_emul_const_value_set(const struct device *dev, unsigned int chan,
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uint32_t value);
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/**
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* @brief Set function used to obtain voltage for input of emulated
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* ADC @p chan
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*
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* @param dev The emulated ADC device
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* @param chan The channel of ADC to which @p func is assigned
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* @param func New function to assign to @p chan
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* @param data Pointer to data passed to @p func on call
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*
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* @return 0 on success
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* @return -EINVAL if an invalid argument is provided
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*/
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int adc_emul_value_func_set(const struct device *dev, unsigned int chan,
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adc_emul_value_func func, void *data);
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/**
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* @brief Set reference voltage
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*
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* @param dev The emulated ADC device
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* @param ref Reference config which is changed
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* @param value New reference voltage in mV
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*
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* @return 0 on success
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* @return -EINVAL if an invalid argument is provided
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*/
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int adc_emul_ref_voltage_set(const struct device *dev, enum adc_reference ref,
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uint16_t value);
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/**
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* @}
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*/
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#ifdef __cplusplus
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}
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#endif
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#endif /* ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_ */
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