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/*
* Copyright (C) 2015 Samsung Electronics
* Przemyslaw Marczak <p.marczak@samsung.com>
*
* 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
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