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