iio: amplifiers: hmc425a: Add support for HMC425A attenuator (a76838df) · Commits · 戴 / test

drivers/iio/amplifiers/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -22,4 +22,14 @@ config AD8366
		To compile this driver as a module, choose M here: the
		module will be called ad8366.

		config HMC425
		tristate "Analog Devices HMC425A and similar GPIO Gain Amplifiers"
		depends on GPIOLIB
		help
		Say yes here to build support for Analog Devices HMC425A and similar
		gain amplifiers or step attenuators.

		To compile this driver as a module, choose M here: the
		module will be called hmc425a.

		endmenu

drivers/iio/amplifiers/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -5,3 +5,4 @@

		# When adding new entries keep the list in alphabetical order
		obj-$(CONFIG_AD8366) += ad8366.o
		obj-$(CONFIG_HMC425) += hmc425a.o

drivers/iio/amplifiers/hmc425a.c

0 → 100644

+248 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* HMC425A and similar Gain Amplifiers
		*
		* Copyright 2020 Analog Devices Inc.
		*/

		#include <linux/device.h>
		#include <linux/err.h>
		#include <linux/gpio/consumer.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/of_device.h>
		#include <linux/of_platform.h>
		#include <linux/platform_device.h>
		#include <linux/slab.h>
		#include <linux/regulator/consumer.h>
		#include <linux/sysfs.h>

		enum hmc425a_type {
		ID_HMC425A,
		};

		struct hmc425a_chip_info {
		const char *name;
		const struct iio_chan_spec *channels;
		unsigned int num_channels;
		unsigned int num_gpios;
		int gain_min;
		int gain_max;
		int default_gain;
		};

		struct hmc425a_state {
		struct regulator *reg;
		struct mutex lock; /* protect sensor state */
		struct hmc425a_chip_info *chip_info;
		struct gpio_descs *gpios;
		enum hmc425a_type type;
		u32 gain;
		};

		static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
		{
		struct hmc425a_state *st = iio_priv(indio_dev);
		DECLARE_BITMAP(values, BITS_PER_TYPE(value));

		values[0] = value;

		gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios->desc,
		NULL, values);
		return 0;
		}

		static int hmc425a_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const chan, int val,
		int *val2, long m)
		{
		struct hmc425a_state *st = iio_priv(indio_dev);
		int code, gain = 0;
		int ret;

		mutex_lock(&st->lock);
		switch (m) {
		case IIO_CHAN_INFO_HARDWAREGAIN:
		code = st->gain;

		switch (st->type) {
		case ID_HMC425A:
		gain = ~code * -500;
		break;
		}

		*val = gain / 1000;
		val2 = (gain % 1000) 1000;

		ret = IIO_VAL_INT_PLUS_MICRO_DB;
		break;
		default:
		ret = -EINVAL;
		}
		mutex_unlock(&st->lock);

		return ret;
		};

		static int hmc425a_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int val,
		int val2, long mask)
		{
		struct hmc425a_state *st = iio_priv(indio_dev);
		struct hmc425a_chip_info *inf = st->chip_info;
		int code = 0, gain;
		int ret;

		if (val < 0)
		gain = (val * 1000) - (val2 / 1000);
		else
		gain = (val * 1000) + (val2 / 1000);

		if (gain > inf->gain_max \|\| gain < inf->gain_min)
		return -EINVAL;

		switch (st->type) {
		case ID_HMC425A:
		code = ~((abs(gain) / 500) & 0x3F);
		break;
		}

		mutex_lock(&st->lock);
		switch (mask) {
		case IIO_CHAN_INFO_HARDWAREGAIN:
		st->gain = code;

		ret = hmc425a_write(indio_dev, st->gain);
		break;
		default:
		ret = -EINVAL;
		}
		mutex_unlock(&st->lock);

		return ret;
		}

		static int hmc425a_write_raw_get_fmt(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		long mask)
		{
		switch (mask) {
		case IIO_CHAN_INFO_HARDWAREGAIN:
		return IIO_VAL_INT_PLUS_MICRO_DB;
		default:
		return -EINVAL;
		}
		}

		static const struct iio_info hmc425a_info = {
		.read_raw = &hmc425a_read_raw,
		.write_raw = &hmc425a_write_raw,
		.write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
		};

		#define HMC425A_CHAN(_channel) \
		{ \
		.type = IIO_VOLTAGE, \
		.output = 1, \
		.indexed = 1, \
		.channel = _channel, \
		.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
		}

		static const struct iio_chan_spec hmc425a_channels[] = {
		HMC425A_CHAN(0),
		};

		/* Match table for of_platform binding */
		static const struct of_device_id hmc425a_of_match[] = {
		{ .compatible = "adi,hmc425a", .data = (void *)ID_HMC425A },
		{},
		};
		MODULE_DEVICE_TABLE(of, hmc425a_of_match);

		static void hmc425a_reg_disable(void *data)
		{
		struct hmc425a_state *st = data;

		regulator_disable(st->reg);
		}

		static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
		[ID_HMC425A] = {
		.name = "hmc425a",
		.channels = hmc425a_channels,
		.num_channels = ARRAY_SIZE(hmc425a_channels),
		.num_gpios = 6,
		.gain_min = -31500,
		.gain_max = 0,
		.default_gain = -0x40, /* set default gain -31.5db*/
		},
		};

		static int hmc425a_probe(struct platform_device *pdev)
		{
		struct iio_dev *indio_dev;
		struct hmc425a_state *st;
		int ret;

		indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
		if (!indio_dev)
		return -ENOMEM;

		st = iio_priv(indio_dev);
		st->type = (enum hmc425a_type)of_device_get_match_data(&pdev->dev);

		st->chip_info = &hmc425a_chip_info_tbl[st->type];
		indio_dev->num_channels = st->chip_info->num_channels;
		indio_dev->channels = st->chip_info->channels;
		indio_dev->name = st->chip_info->name;
		st->gain = st->chip_info->default_gain;

		st->gpios = devm_gpiod_get_array(&pdev->dev, "ctrl", GPIOD_OUT_LOW);
		if (IS_ERR(st->gpios)) {
		ret = PTR_ERR(st->gpios);
		if (ret != -EPROBE_DEFER)
		dev_err(&pdev->dev, "failed to get gpios\n");
		return ret;
		}

		if (st->gpios->ndescs != st->chip_info->num_gpios) {
		dev_err(&pdev->dev, "%d GPIOs needed to operate\n",
		st->chip_info->num_gpios);
		return -ENODEV;
		}

		st->reg = devm_regulator_get(&pdev->dev, "vcc-supply");
		if (IS_ERR(st->reg))
		return PTR_ERR(st->reg);

		ret = regulator_enable(st->reg);
		if (ret)
		return ret;
		ret = devm_add_action_or_reset(&pdev->dev, hmc425a_reg_disable, st);
		if (ret)
		return ret;

		mutex_init(&st->lock);

		indio_dev->dev.parent = &pdev->dev;
		indio_dev->info = &hmc425a_info;
		indio_dev->modes = INDIO_DIRECT_MODE;

		return devm_iio_device_register(&pdev->dev, indio_dev);
		}

		static struct platform_driver hmc425a_driver = {
		.driver = {
		.name = KBUILD_MODNAME,
		.of_match_table = hmc425a_of_match,
		},
		.probe = hmc425a_probe,
		};
		module_platform_driver(hmc425a_driver);

		MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
		MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
		MODULE_LICENSE("GPL v2");

Admin message