iio: adc: Add driver support for AD7292 (506d2e31) · Commits · 戴 / test

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

+10 −0

Original line number	Diff line number	Diff line
		@@ -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

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

0 → 100644

+350 −0

Original line number	Diff line number	Diff line
		// 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");

Admin message