linux/drivers/iio/adc/ad7944.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Analog Devices AD7944/85/86 PulSAR ADC family driver.
 *
 * Copyright 2024 Analog Devices, Inc.
 * Copyright 2024 BayLibre, SAS
 */

#include <linux/align.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/string_helpers.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#define AD7944_INTERNAL_REF_MV …

struct ad7944_timing_spec { … };

enum ad7944_spi_mode { … };

/* maps adi,spi-mode property value to enum */
static const char * const ad7944_spi_modes[] = …;

struct ad7944_adc { … };

/* quite time before CNV rising edge */
#define T_QUIET_NS …

static const struct ad7944_timing_spec ad7944_timing_spec = …;

static const struct ad7944_timing_spec ad7986_timing_spec = …;

struct ad7944_chip_info { … };

/*
 * AD7944_DEFINE_CHIP_INFO - Define a chip info structure for a specific chip
 * @_name: The name of the chip
 * @_ts: The timing specification for the chip
 * @_bits: The number of bits in the conversion result
 * @_diff: Whether the chip is true differential or not
 */
#define AD7944_DEFINE_CHIP_INFO(_name, _ts, _bits, _diff) …

/* pseudo-differential with ground sense */
AD7944_DEFINE_CHIP_INFO(…);
AD7944_DEFINE_CHIP_INFO(…);
/* fully differential */
AD7944_DEFINE_CHIP_INFO(…);

static int ad7944_3wire_cs_mode_init_msg(struct device *dev, struct ad7944_adc *adc,
					 const struct iio_chan_spec *chan)
{ … }

static int ad7944_4wire_mode_init_msg(struct device *dev, struct ad7944_adc *adc,
				      const struct iio_chan_spec *chan)
{ … }

static int ad7944_chain_mode_init_msg(struct device *dev, struct ad7944_adc *adc,
				      const struct iio_chan_spec *chan,
				      u32 n_chain_dev)
{ … }

/**
 * ad7944_convert_and_acquire - Perform a single conversion and acquisition
 * @adc: The ADC device structure
 * Return: 0 on success, a negative error code on failure
 *
 * Perform a conversion and acquisition of a single sample using the
 * pre-optimized adc->msg.
 *
 * Upon successful return adc->sample.raw will contain the conversion result
 * (or adc->chain_mode_buf if the device is using chain mode).
 */
static int ad7944_convert_and_acquire(struct ad7944_adc *adc)
{ … }

static int ad7944_single_conversion(struct ad7944_adc *adc,
				    const struct iio_chan_spec *chan,
				    int *val)
{ … }

static int ad7944_read_raw(struct iio_dev *indio_dev,
			   const struct iio_chan_spec *chan,
			   int *val, int *val2, long info)
{ … }

static const struct iio_info ad7944_iio_info = …;

static irqreturn_t ad7944_trigger_handler(int irq, void *p)
{ … }

/**
 * ad7944_chain_mode_alloc - allocate and initialize channel specs and buffers
 *                           for daisy-chained devices
 * @dev: The device for devm_ functions
 * @chan_template: The channel template for the devices (array of 2 channels
 *                 voltage and timestamp)
 * @n_chain_dev: The number of devices in the chain
 * @chain_chan: Pointer to receive the allocated channel specs
 * @chain_mode_buf: Pointer to receive the allocated rx buffer
 * @chain_scan_masks: Pointer to receive the allocated scan masks
 * Return: 0 on success, a negative error code on failure
 */
static int ad7944_chain_mode_alloc(struct device *dev,
				   const struct iio_chan_spec *chan_template,
				   u32 n_chain_dev,
				   struct iio_chan_spec **chain_chan,
				   void **chain_mode_buf,
				   unsigned long **chain_scan_masks)
{ … }

static const char * const ad7944_power_supplies[] = …;

static int ad7944_probe(struct spi_device *spi)
{ … }

static const struct of_device_id ad7944_of_match[] = …;
MODULE_DEVICE_TABLE(of, ad7944_of_match);

static const struct spi_device_id ad7944_spi_id[] = …;
MODULE_DEVICE_TABLE(spi, ad7944_spi_id);

static struct spi_driver ad7944_driver = …;
module_spi_driver(…) …;

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