Commit 506d2e31 authored by Marcelo Schmitt's avatar Marcelo Schmitt Committed by Jonathan Cameron
Browse files

iio: adc: Add driver support for AD7292 

The AD7292 is a 10-bit monitor and control system with ADC, DACs,
temperature sensor, and GPIOs.

Configure AD7292 devices in direct access mode, enabling single-ended
ADC readings.

Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf



Signed-off-by: default avatarMarcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent d898f9ac

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -906,6 +906,7 @@ M: Marcelo Schmitt <marcelo.schmitt1@gmail.com> 
L:	linux-iio@vger.kernel.org

W:	http://ez.analog.com/community/linux-device-drivers

S:	Supported

F:	drivers/iio/adc/ad7292.c

F:	Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml









ANALOG DEVICES INC AD7606 DRIVER
































drivers/iio/adc/Kconfig



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@@ -55,6 +55,16 @@ config AD7291







	  To compile this driver as a module, choose M here: the









	  module will be called ad7291.



















config AD7292









	tristate "Analog Devices AD7292 ADC driver"









	depends on SPI









	help









	  Say yes here to build support for Analog Devices AD7292









	  8 Channel ADC with temperature sensor.



















	  To compile this driver as a module, choose M here: the









	  module will be called ad7292.



















config AD7298









	tristate "Analog Devices AD7298 ADC driver"









	depends on SPI
































drivers/iio/adc/Makefile



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@@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o







obj-$(CONFIG_AD7124) += ad7124.o









obj-$(CONFIG_AD7266) += ad7266.o









obj-$(CONFIG_AD7291) += ad7291.o









obj-$(CONFIG_AD7292) += ad7292.o









obj-$(CONFIG_AD7298) += ad7298.o









obj-$(CONFIG_AD7923) += ad7923.o









obj-$(CONFIG_AD7476) += ad7476.o
































drivers/iio/adc/ad7292.c
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// SPDX-License-Identifier: GPL-2.0









/*









 * Analog Devices AD7292 SPI ADC driver









 *









 * Copyright 2019 Analog Devices Inc.









 */



















#include <linux/bitfield.h>









#include <linux/device.h>









#include <linux/module.h>









#include <linux/regulator/consumer.h>









#include <linux/spi/spi.h>



















#include <linux/iio/iio.h>



















#define ADI_VENDOR_ID 0x0018



















/* AD7292 registers definition */









#define AD7292_REG_VENDOR_ID		0x00









#define AD7292_REG_CONF_BANK		0x05









#define AD7292_REG_CONV_COMM		0x0E









#define AD7292_REG_ADC_CH(x)		(0x10 + (x))



















/* AD7292 configuration bank subregisters definition */









#define AD7292_BANK_REG_VIN_RNG0	0x10









#define AD7292_BANK_REG_VIN_RNG1	0x11









#define AD7292_BANK_REG_SAMP_MODE	0x12



















#define AD7292_RD_FLAG_MSK(x)		(BIT(7) | ((x) & 0x3F))



















/* AD7292_REG_ADC_CONVERSION */









#define AD7292_ADC_DATA_MASK		GENMASK(15, 6)









#define AD7292_ADC_DATA(x)		FIELD_GET(AD7292_ADC_DATA_MASK, x)



















/* AD7292_CHANNEL_SAMPLING_MODE */









#define AD7292_CH_SAMP_MODE(reg, ch)	(((reg) >> 8) & BIT(ch))



















/* AD7292_CHANNEL_VIN_RANGE */









#define AD7292_CH_VIN_RANGE(reg, ch)	((reg) & BIT(ch))



















#define AD7292_VOLTAGE_CHAN(_chan)					\









{									\









	.type = IIO_VOLTAGE,						\









	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\









			      BIT(IIO_CHAN_INFO_SCALE),			\









	.indexed = 1,							\









	.channel = _chan,						\









}



















static const struct iio_chan_spec ad7292_channels[] = {









	AD7292_VOLTAGE_CHAN(0),









	AD7292_VOLTAGE_CHAN(1),









	AD7292_VOLTAGE_CHAN(2),









	AD7292_VOLTAGE_CHAN(3),









	AD7292_VOLTAGE_CHAN(4),









	AD7292_VOLTAGE_CHAN(5),









	AD7292_VOLTAGE_CHAN(6),









	AD7292_VOLTAGE_CHAN(7)









};



















static const struct iio_chan_spec ad7292_channels_diff[] = {









	{









		.type = IIO_VOLTAGE,









		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),









		.indexed = 1,









		.differential = 1,









		.channel = 0,









		.channel2 = 1,









	},









	AD7292_VOLTAGE_CHAN(2),









	AD7292_VOLTAGE_CHAN(3),









	AD7292_VOLTAGE_CHAN(4),









	AD7292_VOLTAGE_CHAN(5),









	AD7292_VOLTAGE_CHAN(6),









	AD7292_VOLTAGE_CHAN(7)









};



















struct ad7292_state {









	struct spi_device *spi;









	struct regulator *reg;









	unsigned short vref_mv;



















	__be16 d16 ____cacheline_aligned;









	u8 d8[2];









};



















static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)









{









	int ret;



















	st->d8[0] = AD7292_RD_FLAG_MSK(addr);



















	ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);









	if (ret < 0)









		return ret;



















	return be16_to_cpu(st->d16);









}



















static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,









				  unsigned int sub_addr, unsigned int len)









{









	unsigned int shift = 16 - (8 * len);









	int ret;



















	st->d8[0] = AD7292_RD_FLAG_MSK(addr);









	st->d8[1] = sub_addr;



















	ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);









	if (ret < 0)









		return ret;



















	return (be16_to_cpu(st->d16) >> shift);









}



















static int ad7292_single_conversion(struct ad7292_state *st,









				    unsigned int chan_addr)









{









	int ret;



















	struct spi_transfer t[] = {









		{









			.tx_buf = &st->d8,









			.len = 4,









			.delay_usecs = 6,









		}, {









			.rx_buf = &st->d16,









			.len = 2,









		},









	};



















	st->d8[0] = chan_addr;









	st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);



















	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));



















	if (ret < 0)









		return ret;



















	return be16_to_cpu(st->d16);









}



















static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)









{









	int samp_mode, range0, range1, factor = 1;



















	/*









	 * Every AD7292 ADC channel may have its input range adjusted according









	 * to the settings at the ADC sampling mode and VIN range subregisters.









	 * For a given channel, the minimum input range is equal to Vref, and it









	 * may be increased by a multiplier factor of 2 or 4 according to the









	 * following rule:









	 * If channel is being sampled with respect to AGND:









	 *	factor = 4 if VIN range0 and VIN range1 equal 0









	 *	factor = 2 if only one of VIN ranges equal 1









	 *	factor = 1 if both VIN range0 and VIN range1 equal 1









	 * If channel is being sampled with respect to AVDD:









	 *	factor = 4 if VIN range0 and VIN range1 equal 0









	 *	Behavior is undefined if any of VIN range doesn't equal 0









	 */



















	samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,









					   AD7292_BANK_REG_SAMP_MODE, 2);



















	if (samp_mode < 0)









		return samp_mode;



















	range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,









					AD7292_BANK_REG_VIN_RNG0, 2);



















	if (range0 < 0)









		return range0;



















	range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,









					AD7292_BANK_REG_VIN_RNG1, 2);



















	if (range1 < 0)









		return range1;



















	if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {









		/* Sampling with respect to AGND */









		if (!AD7292_CH_VIN_RANGE(range0, channel))









			factor *= 2;



















		if (!AD7292_CH_VIN_RANGE(range1, channel))









			factor *= 2;



















	} else {









		/* Sampling with respect to AVDD */









		if (AD7292_CH_VIN_RANGE(range0, channel) ||









		    AD7292_CH_VIN_RANGE(range1, channel))









			return -EPERM;



















		factor = 4;









	}



















	return factor;









}



















static int ad7292_read_raw(struct iio_dev *indio_dev,









			   const struct iio_chan_spec *chan,









			   int *val, int *val2, long info)









{









	struct ad7292_state *st = iio_priv(indio_dev);









	unsigned int ch_addr;









	int ret;



















	switch (info) {









	case IIO_CHAN_INFO_RAW:









		ch_addr = AD7292_REG_ADC_CH(chan->channel);









		ret = ad7292_single_conversion(st, ch_addr);









		if (ret < 0)









			return ret;



















		*val = AD7292_ADC_DATA(ret);



















		return IIO_VAL_INT;









	case IIO_CHAN_INFO_SCALE:









		/*









		 * To convert a raw value to standard units, the IIO defines









		 * this formula: Scaled value = (raw + offset) * scale.









		 * For the scale to be a correct multiplier for (raw + offset),









		 * it must be calculated as the input range divided by the









		 * number of possible distinct input values. Given the ADC data









		 * is 10 bit long, it may assume 2^10 distinct values.









		 * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2









		 * return type indicates to the IIO API to divide *val by 2 to









		 * the power of *val2 when returning from read_raw.









		 */



















		ret = ad7292_vin_range_multiplier(st, chan->channel);









		if (ret < 0)









			return ret;



















		*val = st->vref_mv * ret;









		*val2 = 10;









		return IIO_VAL_FRACTIONAL_LOG2;









	default:









		break;









	}









	return -EINVAL;









}



















static const struct iio_info ad7292_info = {









	.read_raw = ad7292_read_raw,









};



















static void ad7292_regulator_disable(void *data)









{









	struct ad7292_state *st = data;



















	regulator_disable(st->reg);









}



















static int ad7292_probe(struct spi_device *spi)









{









	struct ad7292_state *st;









	struct iio_dev *indio_dev;









	struct device_node *child;









	bool diff_channels = 0;









	int ret;



















	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));









	if (!indio_dev)









		return -ENOMEM;



















	st = iio_priv(indio_dev);









	st->spi = spi;



















	ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);









	if (ret != ADI_VENDOR_ID) {









		dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);









		return -EINVAL;









	}



















	spi_set_drvdata(spi, indio_dev);



















	st->reg = devm_regulator_get_optional(&spi->dev, "vref");









	if (!IS_ERR(st->reg)) {









		ret = regulator_enable(st->reg);









		if (ret) {









			dev_err(&spi->dev,









				"Failed to enable external vref supply\n");









			return ret;









		}



















		ret = devm_add_action_or_reset(&spi->dev,









					       ad7292_regulator_disable, st);









		if (ret) {









			regulator_disable(st->reg);









			return ret;









		}



















		ret = regulator_get_voltage(st->reg);









		if (ret < 0)









			return ret;



















		st->vref_mv = ret / 1000;









	} else {









		/* Use the internal voltage reference. */









		st->vref_mv = 1250;









	}



















	indio_dev->dev.parent = &spi->dev;









	indio_dev->name = spi_get_device_id(spi)->name;









	indio_dev->modes = INDIO_DIRECT_MODE;









	indio_dev->info = &ad7292_info;



















	for_each_available_child_of_node(spi->dev.of_node, child) {









		diff_channels = of_property_read_bool(child, "diff-channels");









		if (diff_channels)









			break;









	}



















	if (diff_channels) {









		indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);









		indio_dev->channels = ad7292_channels_diff;









	} else {









		indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);









		indio_dev->channels = ad7292_channels;









	}



















	return devm_iio_device_register(&spi->dev, indio_dev);









}



















static const struct spi_device_id ad7292_id_table[] = {









	{ "ad7292", 0 },









	{}









};









MODULE_DEVICE_TABLE(spi, ad7292_id_table);



















static const struct of_device_id ad7292_of_match[] = {









	{ .compatible = "adi,ad7292" },









	{ },









};









MODULE_DEVICE_TABLE(of, ad7292_of_match);



















static struct spi_driver ad7292_driver = {









	.driver = {









		.name = "ad7292",









		.of_match_table = ad7292_of_match,









	},









	.probe = ad7292_probe,









	.id_table = ad7292_id_table,









};









module_spi_driver(ad7292_driver);



















MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt1@gmail.com>");









MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");









MODULE_LICENSE("GPL v2");