iio: frequency: admfm2000: New driver

Dual microwave down converter module with input RF and LO frequency
ranges from 0.5 to 32 GHz and an output IF frequency range from 0.1 to
8 GHz. It consists of a LNA, mixer, IF filter, DSA, and IF amplifier
for each down conversion path.

Signed-off-by: Kim Seer Paller <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

MAINTAINERS

···
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
+F:	drivers/iio/frequency/admfm2000.c
 
 ANALOG DEVICES INC ADMV1013 DRIVER
 M:	Antoniu Miclaus <[e-mail]>

drivers/iio/frequency/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called adf4377.
 
+config ADMFM2000
+	tristate "Analog Devices ADMFM2000 Dual Microwave Down Converter"
+	depends on GPIOLIB
+	help
+	  Say yes here to build support for Analog Devices ADMFM2000 Dual
+	  Microwave Down Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called admfm2000.
+
 config ADMV1013
 	tristate "Analog Devices ADMV1013 Microwave Upconverter"
 	depends on SPI && COMMON_CLK

drivers/iio/frequency/Makefile

···
 obj-$(CONFIG_ADF4350) += adf4350.o
 obj-$(CONFIG_ADF4371) += adf4371.o
 obj-$(CONFIG_ADF4377) += adf4377.o
+obj-$(CONFIG_ADMFM2000) += admfm2000.o
 obj-$(CONFIG_ADMV1013) += admv1013.o
 obj-$(CONFIG_ADMV1014) += admv1014.o
 obj-$(CONFIG_ADMV4420) += admv4420.o

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/mod_devicetable.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 fwnode_handle *child;
+	struct gpio_desc **dsa;
+	struct gpio_desc **sw;
+	int ret, i;
+	bool mode;
+	u32 reg;
+
+	device_for_each_child_node(dev, child) {
+		ret = fwnode_property_read_u32(child, "reg", &reg);
+		if (ret) {
+			fwnode_handle_put(child);
+			return dev_err_probe(dev, ret,
+					     "Failed to get reg property\n");
+		}
+
+		if (reg >= indio_dev->num_channels) {
+			fwnode_handle_put(child);
+			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:
+			fwnode_handle_put(child);
+			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])) {
+				fwnode_handle_put(child);
+				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])) {
+				fwnode_handle_put(child);
+				return dev_err_probe(dev, PTR_ERR(dsa[i]),
+						     "Failed to get gpios\n");
+			}
+		}
+
+		ret = admfm2000_mode(indio_dev, reg, mode);
+		if (ret) {
+			fwnode_handle_put(child);
+			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 <[e-mail]>");
+MODULE_DESCRIPTION("ADMFM2000 Dual Microwave Down Converter");
+MODULE_LICENSE("GPL");