drivers/iio/frequency/admv4420.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
 /*
  * ADMV4420
  *
  * Copyright 2021 Analog Devices Inc.
  */

 #include <linux/bitfield.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 #include <linux/units.h>

 #include <linux/unaligned.h>

 /* ADMV4420 Register Map */
 #define ADMV4420_SPI_CONFIG_1			0x00
 #define ADMV4420_SPI_CONFIG_2			0x01
 #define ADMV4420_CHIPTYPE			0x03
 #define ADMV4420_PRODUCT_ID_L			0x04
 #define ADMV4420_PRODUCT_ID_H			0x05
 #define ADMV4420_SCRATCHPAD			0x0A
 #define ADMV4420_SPI_REV			0x0B
 #define ADMV4420_ENABLES			0x103
 #define ADMV4420_SDO_LEVEL			0x108
 #define ADMV4420_INT_L				0x200
 #define ADMV4420_INT_H				0x201
 #define ADMV4420_FRAC_L				0x202
 #define ADMV4420_FRAC_M				0x203
 #define ADMV4420_FRAC_H				0x204
 #define ADMV4420_MOD_L				0x208
 #define ADMV4420_MOD_M				0x209
 #define ADMV4420_MOD_H				0x20A
 #define ADMV4420_R_DIV_L			0x20C
 #define ADMV4420_R_DIV_H			0x20D
 #define ADMV4420_REFERENCE			0x20E
 #define ADMV4420_VCO_DATA_READBACK1		0x211
 #define ADMV4420_VCO_DATA_READBACK2		0x212
 #define ADMV4420_PLL_MUX_SEL			0x213
 #define ADMV4420_LOCK_DETECT			0x214
 #define ADMV4420_BAND_SELECT			0x215
 #define ADMV4420_VCO_ALC_TIMEOUT		0x216
 #define ADMV4420_VCO_MANUAL			0x217
 #define ADMV4420_ALC				0x219
 #define ADMV4420_VCO_TIMEOUT1			0x21C
 #define ADMV4420_VCO_TIMEOUT2			0x21D
 #define ADMV4420_VCO_BAND_DIV			0x21E
 #define ADMV4420_VCO_READBACK_SEL		0x21F
 #define ADMV4420_AUTOCAL			0x226
 #define ADMV4420_CP_STATE			0x22C
 #define ADMV4420_CP_BLEED_EN			0x22D
 #define ADMV4420_CP_CURRENT			0x22E
 #define ADMV4420_CP_BLEED			0x22F

 #define ADMV4420_SPI_CONFIG_1_SDOACTIVE		(BIT(4) | BIT(3))
 #define ADMV4420_SPI_CONFIG_1_ENDIAN		(BIT(5) | BIT(2))
 #define ADMV4420_SPI_CONFIG_1_SOFTRESET		(BIT(7) | BIT(1))

 #define ADMV4420_REFERENCE_DIVIDE_BY_2_MASK	BIT(0)
 #define ADMV4420_REFERENCE_MODE_MASK		BIT(1)
 #define ADMV4420_REFERENCE_DOUBLER_MASK		BIT(2)

 #define ADMV4420_REF_DIVIDER_MAX_VAL		GENMASK(9, 0)
 #define ADMV4420_N_COUNTER_INT_MAX		GENMASK(15, 0)
 #define ADMV4420_N_COUNTER_FRAC_MAX		GENMASK(23, 0)
 #define ADMV4420_N_COUNTER_MOD_MAX		GENMASK(23, 0)

 #define ENABLE_PLL				BIT(6)
 #define ENABLE_LO				BIT(5)
 #define ENABLE_VCO				BIT(3)
 #define ENABLE_IFAMP				BIT(2)
 #define ENABLE_MIXER				BIT(1)
 #define ENABLE_LNA				BIT(0)

 #define ADMV4420_SCRATCH_PAD_VAL_1              0xAD
 #define ADMV4420_SCRATCH_PAD_VAL_2              0xEA

 #define ADMV4420_REF_FREQ_HZ                    50000000
 #define MAX_N_COUNTER                           655360UL
 #define MAX_R_DIVIDER                           1024
 #define ADMV4420_DEFAULT_LO_FREQ_HZ		16750000000ULL

 enum admv4420_mux_sel {
 	ADMV4420_LOW = 0,
 	ADMV4420_LOCK_DTCT = 1,
 	ADMV4420_R_COUNTER_PER_2 = 4,
 	ADMV4420_N_CONUTER_PER_2 = 5,
 	ADMV4420_HIGH = 8,
 };

 struct admv4420_reference_block {
 	bool doubler_en;
 	bool divide_by_2_en;
 	bool ref_single_ended;
 	u32 divider;
 };

 struct admv4420_n_counter {
 	u32 int_val;
 	u32 frac_val;
 	u32 mod_val;
 	u32 n_counter;
 };

 struct admv4420_state {
 	struct spi_device		*spi;
 	struct regmap			*regmap;
 	u64				vco_freq_hz;
 	u64				lo_freq_hz;
 	struct admv4420_reference_block ref_block;
 	struct admv4420_n_counter	n_counter;
 	enum admv4420_mux_sel		mux_sel;
 	struct mutex			lock;
 	u8				transf_buf[4] __aligned(IIO_DMA_MINALIGN);
 };

 static const struct regmap_config admv4420_regmap_config = {
 	.reg_bits = 16,
 	.val_bits = 8,
 	.read_flag_mask = BIT(7),
 };

 static int admv4420_reg_access(struct iio_dev *indio_dev,
 			       u32 reg, u32 writeval,
 			       u32 *readval)
 {
 	struct admv4420_state *st = iio_priv(indio_dev);

 	if (readval)
 		return regmap_read(st->regmap, reg, readval);
 	else
 		return regmap_write(st->regmap, reg, writeval);
 }

 static int admv4420_set_n_counter(struct admv4420_state *st, u32 int_val,
 				  u32 frac_val, u32 mod_val)
 {
 	int ret;

 	put_unaligned_le32(frac_val, st->transf_buf);
 	ret = regmap_bulk_write(st->regmap, ADMV4420_FRAC_L, st->transf_buf, 3);
 	if (ret)
 		return ret;

 	put_unaligned_le32(mod_val, st->transf_buf);
 	ret = regmap_bulk_write(st->regmap, ADMV4420_MOD_L, st->transf_buf, 3);
 	if (ret)
 		return ret;

 	put_unaligned_le32(int_val, st->transf_buf);
 	return regmap_bulk_write(st->regmap, ADMV4420_INT_L, st->transf_buf, 2);
 }

 static int admv4420_read_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int *val, int *val2, long info)
 {
 	struct admv4420_state *st = iio_priv(indio_dev);

 	switch (info) {
 	case IIO_CHAN_INFO_FREQUENCY:

 		*val = div_u64_rem(st->lo_freq_hz, MICRO, val2);

 		return IIO_VAL_INT_PLUS_MICRO;
 	default:
 		return -EINVAL;
 	}
 }

 static const struct iio_info admv4420_info = {
 	.read_raw = admv4420_read_raw,
 	.debugfs_reg_access = &admv4420_reg_access,
 };

 static const struct iio_chan_spec admv4420_channels[] = {
 	{
 		.type = IIO_ALTVOLTAGE,
 		.output = 0,
 		.indexed = 1,
 		.channel = 0,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_FREQUENCY),
 	},
 };

 static void admv4420_fw_parse(struct admv4420_state *st)
 {
 	struct device *dev = &st->spi->dev;
 	u32 tmp;
 	int ret;

 	ret = device_property_read_u32(dev, "adi,lo-freq-khz", &tmp);
 	if (!ret)
 		st->lo_freq_hz = (u64)tmp * KILO;

 	st->ref_block.ref_single_ended = device_property_read_bool(dev,
 								   "adi,ref-ext-single-ended-en");
 }

 static inline uint64_t admv4420_calc_pfd_vco(struct admv4420_state *st)
 {
 	return div_u64(st->vco_freq_hz * 10, st->n_counter.n_counter);
 }

 static inline uint32_t admv4420_calc_pfd_ref(struct admv4420_state *st)
 {
 	uint32_t tmp;
 	u8 doubler, divide_by_2;

 	doubler = st->ref_block.doubler_en ? 2 : 1;
 	divide_by_2 = st->ref_block.divide_by_2_en ? 2 : 1;
 	tmp = ADMV4420_REF_FREQ_HZ * doubler;

 	return (tmp / (st->ref_block.divider * divide_by_2));
 }

 static int admv4420_calc_parameters(struct admv4420_state *st)
 {
 	u64 pfd_ref, pfd_vco;
 	bool sol_found = false;

 	st->ref_block.doubler_en = false;
 	st->ref_block.divide_by_2_en = false;
 	st->vco_freq_hz = div_u64(st->lo_freq_hz, 2);

 	for (st->ref_block.divider = 1; st->ref_block.divider < MAX_R_DIVIDER;
 	    st->ref_block.divider++) {
 		pfd_ref = admv4420_calc_pfd_ref(st);
 		for (st->n_counter.n_counter = 1; st->n_counter.n_counter < MAX_N_COUNTER;
 		    st->n_counter.n_counter++) {
 			pfd_vco = admv4420_calc_pfd_vco(st);
 			if (pfd_ref == pfd_vco) {
 				sol_found = true;
 				break;
 			}
 		}

 		if (sol_found)
 			break;

 		st->n_counter.n_counter = 1;
 	}
 	if (!sol_found)
 		return -1;

 	st->n_counter.int_val = div_u64_rem(st->n_counter.n_counter, 10, &st->n_counter.frac_val);
 	st->n_counter.mod_val = 10;

 	return 0;
 }

 static int admv4420_setup(struct iio_dev *indio_dev)
 {
 	struct admv4420_state *st = iio_priv(indio_dev);
 	struct device *dev = indio_dev->dev.parent;
 	u32 val;
 	int ret;

 	ret = regmap_write(st->regmap, ADMV4420_SPI_CONFIG_1,
 			   ADMV4420_SPI_CONFIG_1_SOFTRESET);
 	if (ret)
 		return ret;

 	ret = regmap_write(st->regmap, ADMV4420_SPI_CONFIG_1,
 			   ADMV4420_SPI_CONFIG_1_SDOACTIVE |
 			   ADMV4420_SPI_CONFIG_1_ENDIAN);
 	if (ret)
 		return ret;

 	ret = regmap_write(st->regmap,
 			   ADMV4420_SCRATCHPAD,
 			   ADMV4420_SCRATCH_PAD_VAL_1);
 	if (ret)
 		return ret;

 	ret = regmap_read(st->regmap, ADMV4420_SCRATCHPAD, &val);
 	if (ret)
 		return ret;

 	if (val != ADMV4420_SCRATCH_PAD_VAL_1) {
 		dev_err(dev, "Failed ADMV4420 to read/write scratchpad %x ", val);
 		return -EIO;
 	}

 	ret = regmap_write(st->regmap,
 			   ADMV4420_SCRATCHPAD,
 			   ADMV4420_SCRATCH_PAD_VAL_2);
 	if (ret)
 		return ret;

 	ret = regmap_read(st->regmap, ADMV4420_SCRATCHPAD, &val);
 	if (ret)
 		return ret;

 	if (val != ADMV4420_SCRATCH_PAD_VAL_2) {
 		dev_err(dev, "Failed to read/write scratchpad %x ", val);
 		return -EIO;
 	}

 	st->mux_sel = ADMV4420_LOCK_DTCT;
 	st->lo_freq_hz = ADMV4420_DEFAULT_LO_FREQ_HZ;

 	admv4420_fw_parse(st);

 	ret = admv4420_calc_parameters(st);
 	if (ret) {
 		dev_err(dev, "Failed calc parameters for %lld ", st->vco_freq_hz);
 		return ret;
 	}

 	ret = regmap_write(st->regmap, ADMV4420_R_DIV_L,
 			   FIELD_GET(0xFF, st->ref_block.divider));
 	if (ret)
 		return ret;

 	ret = regmap_write(st->regmap, ADMV4420_R_DIV_H,
 			   FIELD_GET(0xFF00, st->ref_block.divider));
 	if (ret)
 		return ret;

 	ret = regmap_write(st->regmap, ADMV4420_REFERENCE,
 			   st->ref_block.divide_by_2_en |
 			   FIELD_PREP(ADMV4420_REFERENCE_MODE_MASK, st->ref_block.ref_single_ended) |
 			   FIELD_PREP(ADMV4420_REFERENCE_DOUBLER_MASK, st->ref_block.doubler_en));
 	if (ret)
 		return ret;

 	ret = admv4420_set_n_counter(st, st->n_counter.int_val,
 				     st->n_counter.frac_val,
 				     st->n_counter.mod_val);
 	if (ret)
 		return ret;

 	ret = regmap_write(st->regmap, ADMV4420_PLL_MUX_SEL, st->mux_sel);
 	if (ret)
 		return ret;

 	return regmap_write(st->regmap, ADMV4420_ENABLES,
 			    ENABLE_PLL | ENABLE_LO | ENABLE_VCO |
 			    ENABLE_IFAMP | ENABLE_MIXER | ENABLE_LNA);
 }

 static int admv4420_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;
 	struct admv4420_state *st;
 	struct regmap *regmap;
 	int ret;

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

 	regmap = devm_regmap_init_spi(spi, &admv4420_regmap_config);
 	if (IS_ERR(regmap))
 		return dev_err_probe(&spi->dev, PTR_ERR(regmap),
 				     "Failed to initializing spi regmap\n");

 	st = iio_priv(indio_dev);
 	st->spi = spi;
 	st->regmap = regmap;

 	indio_dev->name = "admv4420";
 	indio_dev->info = &admv4420_info;
 	indio_dev->channels = admv4420_channels;
 	indio_dev->num_channels = ARRAY_SIZE(admv4420_channels);

 	ret = admv4420_setup(indio_dev);
 	if (ret) {
 		dev_err(&spi->dev, "Setup ADMV4420 failed (%d)\n", ret);
 		return ret;
 	}

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

 static const struct of_device_id admv4420_of_match[] = {
 	{ .compatible = "adi,admv4420" },
 	{ }
 };

 MODULE_DEVICE_TABLE(of, admv4420_of_match);

 static struct spi_driver admv4420_driver = {
 	.driver = {
 		.name = "admv4420",
 		.of_match_table = admv4420_of_match,
 	},
 	.probe = admv4420_probe,
 };

 module_spi_driver(admv4420_driver);

 MODULE_AUTHOR("Cristian Pop <cristian.pop@analog.com>");
 MODULE_DESCRIPTION("Analog Devices ADMV44200 K Band Downconverter");
 MODULE_LICENSE("Dual BSD/GPL");
	// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
	/*
	* ADMV4420
	*
	* Copyright 2021 Analog Devices Inc.
	*/

	#include <linux/bitfield.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/module.h>
	#include <linux/regmap.h>
	#include <linux/spi/spi.h>
	#include <linux/units.h>

	#include <linux/unaligned.h>

	/* ADMV4420 Register Map */
	#define ADMV4420_SPI_CONFIG_1 0x00
	#define ADMV4420_SPI_CONFIG_2 0x01
	#define ADMV4420_CHIPTYPE 0x03
	#define ADMV4420_PRODUCT_ID_L 0x04
	#define ADMV4420_PRODUCT_ID_H 0x05
	#define ADMV4420_SCRATCHPAD 0x0A
	#define ADMV4420_SPI_REV 0x0B
	#define ADMV4420_ENABLES 0x103
	#define ADMV4420_SDO_LEVEL 0x108
	#define ADMV4420_INT_L 0x200
	#define ADMV4420_INT_H 0x201
	#define ADMV4420_FRAC_L 0x202
	#define ADMV4420_FRAC_M 0x203
	#define ADMV4420_FRAC_H 0x204
	#define ADMV4420_MOD_L 0x208
	#define ADMV4420_MOD_M 0x209
	#define ADMV4420_MOD_H 0x20A
	#define ADMV4420_R_DIV_L 0x20C
	#define ADMV4420_R_DIV_H 0x20D
	#define ADMV4420_REFERENCE 0x20E
	#define ADMV4420_VCO_DATA_READBACK1 0x211
	#define ADMV4420_VCO_DATA_READBACK2 0x212
	#define ADMV4420_PLL_MUX_SEL 0x213
	#define ADMV4420_LOCK_DETECT 0x214
	#define ADMV4420_BAND_SELECT 0x215
	#define ADMV4420_VCO_ALC_TIMEOUT 0x216
	#define ADMV4420_VCO_MANUAL 0x217
	#define ADMV4420_ALC 0x219
	#define ADMV4420_VCO_TIMEOUT1 0x21C
	#define ADMV4420_VCO_TIMEOUT2 0x21D
	#define ADMV4420_VCO_BAND_DIV 0x21E
	#define ADMV4420_VCO_READBACK_SEL 0x21F
	#define ADMV4420_AUTOCAL 0x226
	#define ADMV4420_CP_STATE 0x22C
	#define ADMV4420_CP_BLEED_EN 0x22D
	#define ADMV4420_CP_CURRENT 0x22E
	#define ADMV4420_CP_BLEED 0x22F

	#define ADMV4420_SPI_CONFIG_1_SDOACTIVE (BIT(4) \| BIT(3))
	#define ADMV4420_SPI_CONFIG_1_ENDIAN (BIT(5) \| BIT(2))
	#define ADMV4420_SPI_CONFIG_1_SOFTRESET (BIT(7) \| BIT(1))

	#define ADMV4420_REFERENCE_DIVIDE_BY_2_MASK BIT(0)
	#define ADMV4420_REFERENCE_MODE_MASK BIT(1)
	#define ADMV4420_REFERENCE_DOUBLER_MASK BIT(2)

	#define ADMV4420_REF_DIVIDER_MAX_VAL GENMASK(9, 0)
	#define ADMV4420_N_COUNTER_INT_MAX GENMASK(15, 0)
	#define ADMV4420_N_COUNTER_FRAC_MAX GENMASK(23, 0)
	#define ADMV4420_N_COUNTER_MOD_MAX GENMASK(23, 0)

	#define ENABLE_PLL BIT(6)
	#define ENABLE_LO BIT(5)
	#define ENABLE_VCO BIT(3)
	#define ENABLE_IFAMP BIT(2)
	#define ENABLE_MIXER BIT(1)
	#define ENABLE_LNA BIT(0)

	#define ADMV4420_SCRATCH_PAD_VAL_1 0xAD
	#define ADMV4420_SCRATCH_PAD_VAL_2 0xEA

	#define ADMV4420_REF_FREQ_HZ 50000000
	#define MAX_N_COUNTER 655360UL
	#define MAX_R_DIVIDER 1024
	#define ADMV4420_DEFAULT_LO_FREQ_HZ 16750000000ULL

	enum admv4420_mux_sel {
	ADMV4420_LOW = 0,
	ADMV4420_LOCK_DTCT = 1,
	ADMV4420_R_COUNTER_PER_2 = 4,
	ADMV4420_N_CONUTER_PER_2 = 5,
	ADMV4420_HIGH = 8,
	};

	struct admv4420_reference_block {
	bool doubler_en;
	bool divide_by_2_en;
	bool ref_single_ended;
	u32 divider;
	};

	struct admv4420_n_counter {
	u32 int_val;
	u32 frac_val;
	u32 mod_val;
	u32 n_counter;
	};

	struct admv4420_state {
	struct spi_device *spi;
	struct regmap *regmap;
	u64 vco_freq_hz;
	u64 lo_freq_hz;
	struct admv4420_reference_block ref_block;
	struct admv4420_n_counter n_counter;
	enum admv4420_mux_sel mux_sel;
	struct mutex lock;
	u8 transf_buf[4] __aligned(IIO_DMA_MINALIGN);
	};

	static const struct regmap_config admv4420_regmap_config = {
	.reg_bits = 16,
	.val_bits = 8,
	.read_flag_mask = BIT(7),
	};

	static int admv4420_reg_access(struct iio_dev *indio_dev,
	u32 reg, u32 writeval,
	u32 *readval)
	{
	struct admv4420_state *st = iio_priv(indio_dev);

	if (readval)
	return regmap_read(st->regmap, reg, readval);
	else
	return regmap_write(st->regmap, reg, writeval);
	}

	static int admv4420_set_n_counter(struct admv4420_state *st, u32 int_val,
	u32 frac_val, u32 mod_val)
	{
	int ret;

	put_unaligned_le32(frac_val, st->transf_buf);
	ret = regmap_bulk_write(st->regmap, ADMV4420_FRAC_L, st->transf_buf, 3);
	if (ret)
	return ret;

	put_unaligned_le32(mod_val, st->transf_buf);
	ret = regmap_bulk_write(st->regmap, ADMV4420_MOD_L, st->transf_buf, 3);
	if (ret)
	return ret;

	put_unaligned_le32(int_val, st->transf_buf);
	return regmap_bulk_write(st->regmap, ADMV4420_INT_L, st->transf_buf, 2);
	}

	static int admv4420_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long info)
	{
	struct admv4420_state *st = iio_priv(indio_dev);

	switch (info) {
	case IIO_CHAN_INFO_FREQUENCY:

	*val = div_u64_rem(st->lo_freq_hz, MICRO, val2);

	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	}

	static const struct iio_info admv4420_info = {
	.read_raw = admv4420_read_raw,
	.debugfs_reg_access = &admv4420_reg_access,
	};

	static const struct iio_chan_spec admv4420_channels[] = {
	{
	.type = IIO_ALTVOLTAGE,
	.output = 0,
	.indexed = 1,
	.channel = 0,
	.info_mask_separate = BIT(IIO_CHAN_INFO_FREQUENCY),
	},
	};

	static void admv4420_fw_parse(struct admv4420_state *st)
	{
	struct device *dev = &st->spi->dev;
	u32 tmp;
	int ret;

	ret = device_property_read_u32(dev, "adi,lo-freq-khz", &tmp);
	if (!ret)
	st->lo_freq_hz = (u64)tmp * KILO;

	st->ref_block.ref_single_ended = device_property_read_bool(dev,
	"adi,ref-ext-single-ended-en");
	}

	static inline uint64_t admv4420_calc_pfd_vco(struct admv4420_state *st)
	{
	return div_u64(st->vco_freq_hz * 10, st->n_counter.n_counter);
	}

	static inline uint32_t admv4420_calc_pfd_ref(struct admv4420_state *st)
	{
	uint32_t tmp;
	u8 doubler, divide_by_2;

	doubler = st->ref_block.doubler_en ? 2 : 1;
	divide_by_2 = st->ref_block.divide_by_2_en ? 2 : 1;
	tmp = ADMV4420_REF_FREQ_HZ * doubler;

	return (tmp / (st->ref_block.divider * divide_by_2));
	}

	static int admv4420_calc_parameters(struct admv4420_state *st)
	{
	u64 pfd_ref, pfd_vco;
	bool sol_found = false;

	st->ref_block.doubler_en = false;
	st->ref_block.divide_by_2_en = false;
	st->vco_freq_hz = div_u64(st->lo_freq_hz, 2);

	for (st->ref_block.divider = 1; st->ref_block.divider < MAX_R_DIVIDER;
	st->ref_block.divider++) {
	pfd_ref = admv4420_calc_pfd_ref(st);
	for (st->n_counter.n_counter = 1; st->n_counter.n_counter < MAX_N_COUNTER;
	st->n_counter.n_counter++) {
	pfd_vco = admv4420_calc_pfd_vco(st);
	if (pfd_ref == pfd_vco) {
	sol_found = true;
	break;
	}
	}

	if (sol_found)
	break;

	st->n_counter.n_counter = 1;
	}
	if (!sol_found)
	return -1;

	st->n_counter.int_val = div_u64_rem(st->n_counter.n_counter, 10, &st->n_counter.frac_val);
	st->n_counter.mod_val = 10;

	return 0;
	}

	static int admv4420_setup(struct iio_dev *indio_dev)
	{
	struct admv4420_state *st = iio_priv(indio_dev);
	struct device *dev = indio_dev->dev.parent;
	u32 val;
	int ret;

	ret = regmap_write(st->regmap, ADMV4420_SPI_CONFIG_1,
	ADMV4420_SPI_CONFIG_1_SOFTRESET);
	if (ret)
	return ret;

	ret = regmap_write(st->regmap, ADMV4420_SPI_CONFIG_1,
	ADMV4420_SPI_CONFIG_1_SDOACTIVE \|
	ADMV4420_SPI_CONFIG_1_ENDIAN);
	if (ret)
	return ret;

	ret = regmap_write(st->regmap,
	ADMV4420_SCRATCHPAD,
	ADMV4420_SCRATCH_PAD_VAL_1);
	if (ret)
	return ret;

	ret = regmap_read(st->regmap, ADMV4420_SCRATCHPAD, &val);
	if (ret)
	return ret;

	if (val != ADMV4420_SCRATCH_PAD_VAL_1) {
	dev_err(dev, "Failed ADMV4420 to read/write scratchpad %x ", val);
	return -EIO;
	}

	ret = regmap_write(st->regmap,
	ADMV4420_SCRATCHPAD,
	ADMV4420_SCRATCH_PAD_VAL_2);
	if (ret)
	return ret;

	ret = regmap_read(st->regmap, ADMV4420_SCRATCHPAD, &val);
	if (ret)
	return ret;

	if (val != ADMV4420_SCRATCH_PAD_VAL_2) {
	dev_err(dev, "Failed to read/write scratchpad %x ", val);
	return -EIO;
	}

	st->mux_sel = ADMV4420_LOCK_DTCT;
	st->lo_freq_hz = ADMV4420_DEFAULT_LO_FREQ_HZ;

	admv4420_fw_parse(st);

	ret = admv4420_calc_parameters(st);
	if (ret) {
	dev_err(dev, "Failed calc parameters for %lld ", st->vco_freq_hz);
	return ret;
	}

	ret = regmap_write(st->regmap, ADMV4420_R_DIV_L,
	FIELD_GET(0xFF, st->ref_block.divider));
	if (ret)
	return ret;

	ret = regmap_write(st->regmap, ADMV4420_R_DIV_H,
	FIELD_GET(0xFF00, st->ref_block.divider));
	if (ret)
	return ret;

	ret = regmap_write(st->regmap, ADMV4420_REFERENCE,
	st->ref_block.divide_by_2_en \|
	FIELD_PREP(ADMV4420_REFERENCE_MODE_MASK, st->ref_block.ref_single_ended) \|
	FIELD_PREP(ADMV4420_REFERENCE_DOUBLER_MASK, st->ref_block.doubler_en));
	if (ret)
	return ret;

	ret = admv4420_set_n_counter(st, st->n_counter.int_val,
	st->n_counter.frac_val,
	st->n_counter.mod_val);
	if (ret)
	return ret;

	ret = regmap_write(st->regmap, ADMV4420_PLL_MUX_SEL, st->mux_sel);
	if (ret)
	return ret;

	return regmap_write(st->regmap, ADMV4420_ENABLES,
	ENABLE_PLL \| ENABLE_LO \| ENABLE_VCO \|
	ENABLE_IFAMP \| ENABLE_MIXER \| ENABLE_LNA);
	}

	static int admv4420_probe(struct spi_device *spi)
	{
	struct iio_dev *indio_dev;
	struct admv4420_state *st;
	struct regmap *regmap;
	int ret;

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

	regmap = devm_regmap_init_spi(spi, &admv4420_regmap_config);
	if (IS_ERR(regmap))
	return dev_err_probe(&spi->dev, PTR_ERR(regmap),
	"Failed to initializing spi regmap\n");

	st = iio_priv(indio_dev);
	st->spi = spi;
	st->regmap = regmap;

	indio_dev->name = "admv4420";
	indio_dev->info = &admv4420_info;
	indio_dev->channels = admv4420_channels;
	indio_dev->num_channels = ARRAY_SIZE(admv4420_channels);

	ret = admv4420_setup(indio_dev);
	if (ret) {
	dev_err(&spi->dev, "Setup ADMV4420 failed (%d)\n", ret);
	return ret;
	}

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

	static const struct of_device_id admv4420_of_match[] = {
	{ .compatible = "adi,admv4420" },
	{ }
	};

	MODULE_DEVICE_TABLE(of, admv4420_of_match);

	static struct spi_driver admv4420_driver = {
	.driver = {
	.name = "admv4420",
	.of_match_table = admv4420_of_match,
	},
	.probe = admv4420_probe,
	};

	module_spi_driver(admv4420_driver);

	MODULE_AUTHOR("Cristian Pop <cristian.pop@analog.com>");
	MODULE_DESCRIPTION("Analog Devices ADMV44200 K Band Downconverter");
	MODULE_LICENSE("Dual BSD/GPL");