drivers/iio/frequency/admfm2000.c

// SPDX-License-Identifier: GPL-2.0
/*
 * ADMFM2000 Dual Microwave Down Converter
 *
 * Copyright 2024 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>

#define ADMFM2000_MIXER_MODE		0
#define ADMFM2000_DIRECT_IF_MODE	1
#define ADMFM2000_DSA_GPIOS		5
#define ADMFM2000_MODE_GPIOS		2
#define ADMFM2000_MAX_GAIN		0
#define ADMFM2000_MIN_GAIN		-31000
#define ADMFM2000_DEFAULT_GAIN		-0x20

struct admfm2000_state {
	struct mutex			lock; /* protect sensor state */
	struct gpio_desc		*sw1_ch[2];
	struct gpio_desc		*sw2_ch[2];
	struct gpio_desc		*dsa1_gpios[5];
	struct gpio_desc		*dsa2_gpios[5];
	u32				gain[2];
};

static int admfm2000_mode(struct iio_dev *indio_dev, u32 chan, u32 mode)
{
	struct admfm2000_state *st = iio_priv(indio_dev);
	int i;

	switch (mode) {
	case ADMFM2000_MIXER_MODE:
		for (i = 0; i < ADMFM2000_MODE_GPIOS; i++) {
			gpiod_set_value_cansleep(st->sw1_ch[i], (chan == 0) ? 1 : 0);
			gpiod_set_value_cansleep(st->sw2_ch[i], (chan == 0) ? 0 : 1);
		}
		return 0;
	case ADMFM2000_DIRECT_IF_MODE:
		for (i = 0; i < ADMFM2000_MODE_GPIOS; i++) {
			gpiod_set_value_cansleep(st->sw1_ch[i], (chan == 0) ? 0 : 1);
			gpiod_set_value_cansleep(st->sw2_ch[i], (chan == 0) ? 1 : 0);
		}
		return 0;
	default:
		return -EINVAL;
	}
}

static int admfm2000_attenuation(struct iio_dev *indio_dev, u32 chan, u32 value)
{
	struct admfm2000_state *st = iio_priv(indio_dev);
	int i;

	switch (chan) {
	case 0:
		for (i = 0; i < ADMFM2000_DSA_GPIOS; i++)
			gpiod_set_value_cansleep(st->dsa1_gpios[i], value & (1 << i));
		return 0;
	case 1:
		for (i = 0; i < ADMFM2000_DSA_GPIOS; i++)
			gpiod_set_value_cansleep(st->dsa2_gpios[i], value & (1 << i));
		return 0;
	default:
		return -EINVAL;
	}
}

static int admfm2000_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan, int *val,
			      int *val2, long mask)
{
	struct admfm2000_state *st = iio_priv(indio_dev);
	int gain;

	switch (mask) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		mutex_lock(&st->lock);
		gain = ~(st->gain[chan->channel]) * -1000;
		*val = gain / 1000;
		*val2 = (gain % 1000) * 1000;
		mutex_unlock(&st->lock);

		return IIO_VAL_INT_PLUS_MICRO_DB;
	default:
		return -EINVAL;
	}
}

static int admfm2000_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan, int val,
			       int val2, long mask)
{
	struct admfm2000_state *st = iio_priv(indio_dev);
	int gain, ret;

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

	if (gain > ADMFM2000_MAX_GAIN || gain < ADMFM2000_MIN_GAIN)
		return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_HARDWAREGAIN:
		mutex_lock(&st->lock);
		st->gain[chan->channel] = ~((abs(gain) / 1000) & 0x1F);

		ret = admfm2000_attenuation(indio_dev, chan->channel,
					    st->gain[chan->channel]);
		mutex_unlock(&st->lock);
		return ret;
	default:
		return -EINVAL;
	}
}

static int admfm2000_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 admfm2000_info = {
	.read_raw = &admfm2000_read_raw,
	.write_raw = &admfm2000_write_raw,
	.write_raw_get_fmt = &admfm2000_write_raw_get_fmt,
};

#define ADMFM2000_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 admfm2000_channels[] = {
	ADMFM2000_CHAN(0),
	ADMFM2000_CHAN(1),
};

static int admfm2000_channel_config(struct admfm2000_state *st,
				    struct iio_dev *indio_dev)
{
	struct platform_device *pdev = to_platform_device(indio_dev->dev.parent);
	struct device *dev = &pdev->dev;
	struct gpio_desc **dsa;
	struct gpio_desc **sw;
	int ret, i;
	bool mode;
	u32 reg;

	device_for_each_child_node_scoped(dev, child) {
		ret = fwnode_property_read_u32(child, "reg", &reg);
		if (ret)
			return dev_err_probe(dev, ret,
					     "Failed to get reg property\n");

		if (reg >= indio_dev->num_channels)
			return dev_err_probe(dev, -EINVAL, "reg bigger than: %d\n",
					     indio_dev->num_channels);

		if (fwnode_property_present(child, "adi,mixer-mode"))
			mode = ADMFM2000_MIXER_MODE;
		else
			mode = ADMFM2000_DIRECT_IF_MODE;

		switch (reg) {
		case 0:
			sw = st->sw1_ch;
			dsa = st->dsa1_gpios;
			break;
		case 1:
			sw = st->sw2_ch;
			dsa = st->dsa2_gpios;
			break;
		default:
			return -EINVAL;
		}

		for (i = 0; i < ADMFM2000_MODE_GPIOS; i++) {
			sw[i] = devm_fwnode_gpiod_get_index(dev, child, "switch",
							    i, GPIOD_OUT_LOW, NULL);
			if (IS_ERR(sw[i]))
				return dev_err_probe(dev, PTR_ERR(sw[i]),
						     "Failed to get gpios\n");
		}

		for (i = 0; i < ADMFM2000_DSA_GPIOS; i++) {
			dsa[i] = devm_fwnode_gpiod_get_index(dev, child,
							     "attenuation", i,
							     GPIOD_OUT_LOW, NULL);
			if (IS_ERR(dsa[i]))
				return dev_err_probe(dev, PTR_ERR(dsa[i]),
						     "Failed to get gpios\n");
		}

		ret = admfm2000_mode(indio_dev, reg, mode);
		if (ret)
			return ret;
	}

	return 0;
}

static int admfm2000_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct admfm2000_state *st;
	struct iio_dev *indio_dev;
	int ret;

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

	st = iio_priv(indio_dev);

	indio_dev->name = "admfm2000";
	indio_dev->num_channels = ARRAY_SIZE(admfm2000_channels);
	indio_dev->channels = admfm2000_channels;
	indio_dev->info = &admfm2000_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	st->gain[0] = ADMFM2000_DEFAULT_GAIN;
	st->gain[1] = ADMFM2000_DEFAULT_GAIN;

	mutex_init(&st->lock);

	ret = admfm2000_channel_config(st, indio_dev);
	if (ret)
		return ret;

	return devm_iio_device_register(dev, indio_dev);
}

static const struct of_device_id admfm2000_of_match[] = {
	{ .compatible = "adi,admfm2000" },
	{ }
};
MODULE_DEVICE_TABLE(of, admfm2000_of_match);

static struct platform_driver admfm2000_driver = {
	.driver = {
		.name = "admfm2000",
		.of_match_table = admfm2000_of_match,
	},
	.probe = admfm2000_probe,
};
module_platform_driver(admfm2000_driver);

MODULE_AUTHOR("Kim Seer Paller <kimseer.paller@analog.com>");
MODULE_DESCRIPTION("ADMFM2000 Dual Microwave Down Converter");
MODULE_LICENSE("GPL");