/* * Copyright (C) 2015 Samsung Electronics * Przemyslaw Marczak * * SPDX-License-Identifier: GPL-2.0+ */ #ifndef _ADC_H_ #define _ADC_H_ /* ADC_CHANNEL() - ADC channel bit mask, to select only required channels */ #define ADC_CHANNEL(x) (1 << x) /* The last possible selected channel with 32-bit mask */ #define ADC_MAX_CHANNEL 31 /** * adc_data_format: define the ADC output data format, can be useful when * the device's input Voltage range is bipolar. * - ADC_DATA_FORMAT_BIN - binary offset * - ADC_DATA_FORMAT_2S - two's complement * * Note: Device's driver should fill the 'data_format' field of its uclass's * platform data using one of the above data format types. */ enum adc_data_format { ADC_DATA_FORMAT_BIN, ADC_DATA_FORMAT_2S, }; /** * struct adc_channel - structure to hold channel conversion data. * Useful to keep the result of a multi-channel conversion output. * * @id - channel id * @data - channel conversion data */ struct adc_channel { int id; unsigned int data; }; /** * struct adc_uclass_platdata - basic ADC info * * Note: The positive/negative reference Voltage is only a name and it doesn't * provide an information about the value polarity. It is possible, for both * values to be a negative or positive. For this purpose the uclass's platform * data provides a bool fields: 'vdd/vss_supply_is_negative'. This is useful, * since the regulator API returns only a positive Voltage values. * * To get the reference Voltage values with polarity, use functions: * - adc_vdd_value() * - adc_vss_value() * Those are useful for some cases of ADC's references, e.g.: * * Vdd: +3.3V; Vss: -3.3V -> 6.6 Vdiff * * Vdd: +3.3V; Vss: +0.3V -> 3.0 Vdiff * * Vdd: +3.3V; Vss: 0.0V -> 3.3 Vdiff * The last one is usually standard and doesn't require the fdt polarity info. * * For more informations read binding info: * - doc/device-tree-bindings/adc/adc.txt * * @data_mask - conversion output data mask * @data_timeout_us - single channel conversion timeout * @multidata_timeout_us - multi channel conversion timeout * @channel_mask - bit mask of available channels [0:31] * @vdd_supply - positive reference Voltage supply (regulator) * @vss_supply - negative reference Voltage supply (regulator) * @vdd_polarity_negative - positive reference Voltage has negative polarity * @vss_polarity_negative - negative reference Voltage has negative polarity * @vdd_microvolts - positive reference Voltage value * @vss_microvolts - negative reference Voltage value */ struct adc_uclass_platdata { int data_format; unsigned int data_mask; unsigned int data_timeout_us; unsigned int multidata_timeout_us; unsigned int channel_mask; struct udevice *vdd_supply; struct udevice *vss_supply; bool vdd_polarity_negative; bool vss_polarity_negative; int vdd_microvolts; int vss_microvolts; }; /** * struct adc_ops - ADC device operations for single/multi-channel operation. */ struct adc_ops { /** * start_channel() - start conversion with its default parameters * for the given channel number. * * @dev: ADC device to init * @channel: analog channel number * @return: 0 if OK, -ve on error */ int (*start_channel)(struct udevice *dev, int channel); /** * start_channels() - start conversion with its default parameters * for the channel numbers selected by the bit mask. * * This is optional, useful when the hardware supports multichannel * conversion by the single software trigger. * * @dev: ADC device to init * @channel_mask: bit mask of selected analog channels * @return: 0 if OK, -ve on error */ int (*start_channels)(struct udevice *dev, unsigned int channel_mask); /** * channel_data() - get conversion output data for the given channel. * * Note: The implementation of this function should only check, that * the conversion data is available at the call time. If the hardware * requires some delay to get the data, then this function should * return with -EBUSY value. The ADC API will call it in a loop, * until the data is available or the timeout expires. The maximum * timeout for this operation is defined by the field 'data_timeout_us' * in ADC uclasses platform data structure. * * @dev: ADC device to trigger * @channel: selected analog channel number * @data: returned pointer to selected channel's output data * @return: 0 if OK, -EBUSY if busy, and other negative on error */ int (*channel_data)(struct udevice *dev, int channel, unsigned int *data); /** * channels_data() - get conversion data for the selected channels. * * This is optional, useful when multichannel conversion is supported * by the hardware, by the single software trigger. * * For the proper implementation, please look at the 'Note' for the * above method. The only difference is in used timeout value, which * is defined by field 'multidata_timeout_us'. * * @dev: ADC device to trigger * @channel_mask: bit mask of selected analog channels * @channels: returned pointer to array of output data for channels * selected by the given mask * @return: 0 if OK, -ve on error */ int (*channels_data)(struct udevice *dev, unsigned int channel_mask, struct adc_channel *channels); /** * stop() - stop conversion of the given ADC device * * @dev: ADC device to stop * @return: 0 if OK, -ve on error */ int (*stop)(struct udevice *dev); }; /** * adc_start_channel() - start conversion for given device/channel and exit. * * @dev: ADC device * @channel: analog channel number * @return: 0 if OK, -ve on error */ int adc_start_channel(struct udevice *dev, int channel); /** * adc_start_channels() - start conversion for given device/channels and exit. * * Note: * To use this function, device must implement method: start_channels(). * * @dev: ADC device to start * @channel_mask: channel selection - a bit mask * @channel_mask: bit mask of analog channels * @return: 0 if OK, -ve on error */ int adc_start_channels(struct udevice *dev, unsigned int channel_mask); /** * adc_channel_data() - get conversion data for the given device channel number. * * @dev: ADC device to read * @channel: analog channel number * @data: pointer to returned channel's data * @return: 0 if OK, -ve on error */ int adc_channel_data(struct udevice *dev, int channel, unsigned int *data); /** * adc_channels_data() - get conversion data for the channels selected by mask * * Note: * To use this function, device must implement methods: * - start_channels() * - channels_data() * * @dev: ADC device to read * @channel_mask: channel selection - a bit mask * @channels: pointer to structure array of returned data for each channel * @return: 0 if OK, -ve on error */ int adc_channels_data(struct udevice *dev, unsigned int channel_mask, struct adc_channel *channels); /** * adc_data_mask() - get data mask (ADC resolution bitmask) for given ADC device * * This can be used if adc uclass platform data is filled. * * @dev: ADC device to check * @data_mask: pointer to the returned data bitmask * @return: 0 if OK, -ve on error */ int adc_data_mask(struct udevice *dev, unsigned int *data_mask); /** * adc_channel_single_shot() - get output data of conversion for the ADC * device's channel. This function searches for the device with the given name, * starts the given channel conversion and returns the output data. * * Note: To use this function, device must implement metods: * - start_channel() * - channel_data() * * @name: device's name to search * @channel: device's input channel to init * @data: pointer to conversion output data * @return: 0 if OK, -ve on error */ int adc_channel_single_shot(const char *name, int channel, unsigned int *data); /** * adc_channels_single_shot() - get ADC conversion output data for the selected * device's channels. This function searches for the device by the given name, * starts the selected channels conversion and returns the output data as array * of type 'struct adc_channel'. * * Note: This function can be used if device implements one of ADC's single * or multi-channel operation API. If multi-channel operation is not supported, * then each selected channel is triggered by the sequence start/data in a loop. * * @name: device's name to search * @channel_mask: channel selection - a bit mask * @channels: pointer to conversion output data for the selected channels * @return: 0 if OK, -ve on error */ int adc_channels_single_shot(const char *name, unsigned int channel_mask, struct adc_channel *channels); /** * adc_vdd_value() - get the ADC device's positive reference Voltage value * * Note: Depending on bool value 'vdd_supply_is_negative' of platform data, * the returned uV value can be negative, and it's not an error. * * @dev: ADC device to check * @uV: Voltage value with polarization sign (uV) * @return: 0 on success or -ve on error */ int adc_vdd_value(struct udevice *dev, int *uV); /** * adc_vss_value() - get the ADC device's negative reference Voltage value * * Note: Depending on bool value 'vdd_supply_is_negative' of platform data, * the returned uV value can be negative, and it's not an error. * * @dev: ADC device to check * @uV: Voltage value with polarization sign (uV) * @return: 0 on success or -ve on error */ int adc_vss_value(struct udevice *dev, int *uV); /** * adc_stop() - stop operation for given ADC device. * * @dev: ADC device to stop * @return: 0 if OK, -ve on error */ int adc_stop(struct udevice *dev); #endif