linux/drivers/iio/adc/mcp320x.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Oskar Andero <[email protected]>
 * Copyright (C) 2014 Rose Technology
 * 	   Allan Bendorff Jensen <[email protected]>
 *	   Soren Andersen <[email protected]>
 *
 * Driver for following ADC chips from Microchip Technology's:
 * 10 Bit converter
 * MCP3001
 * MCP3002
 * MCP3004
 * MCP3008
 * ------------
 * 12 bit converter
 * MCP3201
 * MCP3202
 * MCP3204
 * MCP3208
 * ------------
 * 13 bit converter
 * MCP3301
 * ------------
 * 22 bit converter
 * MCP3550
 * MCP3551
 * MCP3553
 *
 * Datasheet can be found here:
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf  mcp3002
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf  mcp3004/08
 * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf  mcp3201
 * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf  mcp3202
 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf  mcp3204/08
 * https://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf  mcp3301
 * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf  mcp3550/1/3
 */

#include <linux/err.h>
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/iio/iio.h>
#include <linux/regulator/consumer.h>

enum { … };

struct mcp320x_chip_info { … };

/**
 * struct mcp320x - Microchip SPI ADC instance
 * @spi: SPI slave (parent of the IIO device)
 * @msg: SPI message to select a channel and receive a value from the ADC
 * @transfer: SPI transfers used by @msg
 * @start_conv_msg: SPI message to start a conversion by briefly asserting CS
 * @start_conv_transfer: SPI transfer used by @start_conv_msg
 * @reg: regulator generating Vref
 * @lock: protects read sequences
 * @chip_info: ADC properties
 * @tx_buf: buffer for @transfer[0] (not used on single-channel converters)
 * @rx_buf: buffer for @transfer[1]
 */
struct mcp320x { … };

static int mcp320x_channel_to_tx_data(int device_index,
			const unsigned int channel, bool differential)
{ … }

static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
				  bool differential, int device_index, int *val)
{ … }

static int mcp320x_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *channel, int *val,
			    int *val2, long mask)
{ … }

#define MCP320X_VOLTAGE_CHANNEL(num) …

#define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2) …

static const struct iio_chan_spec mcp3201_channels[] = …;

static const struct iio_chan_spec mcp3202_channels[] = …;

static const struct iio_chan_spec mcp3204_channels[] = …;

static const struct iio_chan_spec mcp3208_channels[] = …;

static const struct iio_info mcp320x_info = …;

static const struct mcp320x_chip_info mcp320x_chip_infos[] = …;

static void mcp320x_regulator_disable(void *reg)
{ … }

static int mcp320x_probe(struct spi_device *spi)
{ … }

static const struct of_device_id mcp320x_dt_ids[] = …;
MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);

static const struct spi_device_id mcp320x_id[] = …;
MODULE_DEVICE_TABLE(spi, mcp320x_id);

static struct spi_driver mcp320x_driver = …;
module_spi_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;