1 /** 2 * @file 3 * 4 * @brief Backend API for emulated ADC 5 */ 6 7 /* 8 * Copyright 2021 Google LLC 9 * 10 * SPDX-License-Identifier: Apache-2.0 11 */ 12 #ifndef ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_ 13 #define ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_ 14 15 #include <zephyr/types.h> 16 #include <zephyr/drivers/adc.h> 17 18 #ifdef __cplusplus 19 extern "C" { 20 #endif 21 22 /** 23 * @brief Emulated ADC backend API 24 * @defgroup adc_emul Emulated ADC 25 * @ingroup adc_interface 26 * @{ 27 * 28 * Behaviour of emulated ADC is application-defined. As-such, each 29 * application may 30 * 31 * - define a Device Tree overlay file to indicate the number of ADC 32 * controllers as well as the number of channels for each controller 33 * - set default reference voltages in Device Tree or using 34 * @ref adc_emul_ref_voltage_set 35 * - asynchronously call @ref adc_emul_const_value_set in order to set 36 * constant mV value on emulated ADC input 37 * - asynchronously call @ref adc_emul_value_func_set in order to assign 38 * function which will be used to obtain voltage on emulated ADC input 39 * 40 * An example of an appropriate Device Tree overlay file is in 41 * tests/drivers/adc/adc_api/boards/native_posix.overlay 42 * 43 * An example of using emulated ADC backend API is in the file 44 * tests/drivers/adc/adc_emul/src/main.c 45 */ 46 47 /** 48 * @brief Type definition of the function which is used to obtain ADC 49 * mV input values 50 * 51 * @param dev Pointer to the device structure for the driver instance 52 * @param chan ADC channel to sample 53 * @param data User data which was passed on @ref adc_emul_value_func_set 54 * @param result The result value which will be set as input for ADC @p chan 55 * 56 * @return 0 on success 57 * @return other as error code which ends ADC context 58 */ 59 typedef int (*adc_emul_value_func)(const struct device *dev, unsigned int chan, 60 void *data, uint32_t *result); 61 62 /** 63 * @brief Set constant mV value input for emulated ADC @p chan 64 * 65 * @param dev The emulated ADC device 66 * @param chan The channel of ADC which input is assigned 67 * @param value New voltage in mV to assign to @p chan input 68 * 69 * @return 0 on success 70 * @return -EINVAL if an invalid argument is provided 71 */ 72 int adc_emul_const_value_set(const struct device *dev, unsigned int chan, 73 uint32_t value); 74 75 /** 76 * @brief Set function used to obtain voltage for input of emulated 77 * ADC @p chan 78 * 79 * @param dev The emulated ADC device 80 * @param chan The channel of ADC to which @p func is assigned 81 * @param func New function to assign to @p chan 82 * @param data Pointer to data passed to @p func on call 83 * 84 * @return 0 on success 85 * @return -EINVAL if an invalid argument is provided 86 */ 87 int adc_emul_value_func_set(const struct device *dev, unsigned int chan, 88 adc_emul_value_func func, void *data); 89 90 /** 91 * @brief Set reference voltage 92 * 93 * @param dev The emulated ADC device 94 * @param ref Reference config which is changed 95 * @param value New reference voltage in mV 96 * 97 * @return 0 on success 98 * @return -EINVAL if an invalid argument is provided 99 */ 100 int adc_emul_ref_voltage_set(const struct device *dev, enum adc_reference ref, 101 uint16_t value); 102 /** 103 * @} 104 */ 105 106 #ifdef __cplusplus 107 } 108 #endif 109 110 #endif /* ZEPHYR_INCLUDE_DRIVERS_ADC_ADC_EMUL_H_ */ 111
