1 files changed, 616 insertions, 0 deletions

diff --git a/drivers/iio/frequency/adf4371.c b/drivers/iio/frequency/adf4371.c
new file mode 100644
index 000000000..b27088464
--- /dev/null
+++ b/drivers/iio/frequency/adf4371.c
@@ -0,0 +1,616 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices ADF4371 SPI Wideband Synthesizer driver
+ *
+ * Copyright 2019 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gcd.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+
+/* Registers address macro */
+#define ADF4371_REG(x)			(x)
+
+/* ADF4371_REG0 */
+#define ADF4371_ADDR_ASC_MSK		BIT(2)
+#define ADF4371_ADDR_ASC(x)		FIELD_PREP(ADF4371_ADDR_ASC_MSK, x)
+#define ADF4371_ADDR_ASC_R_MSK		BIT(5)
+#define ADF4371_ADDR_ASC_R(x)		FIELD_PREP(ADF4371_ADDR_ASC_R_MSK, x)
+#define ADF4371_RESET_CMD		0x81
+
+/* ADF4371_REG17 */
+#define ADF4371_FRAC2WORD_L_MSK		GENMASK(7, 1)
+#define ADF4371_FRAC2WORD_L(x)		FIELD_PREP(ADF4371_FRAC2WORD_L_MSK, x)
+#define ADF4371_FRAC1WORD_MSK		BIT(0)
+#define ADF4371_FRAC1WORD(x)		FIELD_PREP(ADF4371_FRAC1WORD_MSK, x)
+
+/* ADF4371_REG18 */
+#define ADF4371_FRAC2WORD_H_MSK		GENMASK(6, 0)
+#define ADF4371_FRAC2WORD_H(x)		FIELD_PREP(ADF4371_FRAC2WORD_H_MSK, x)
+
+/* ADF4371_REG1A */
+#define ADF4371_MOD2WORD_MSK		GENMASK(5, 0)
+#define ADF4371_MOD2WORD(x)		FIELD_PREP(ADF4371_MOD2WORD_MSK, x)
+
+/* ADF4371_REG24 */
+#define ADF4371_RF_DIV_SEL_MSK		GENMASK(6, 4)
+#define ADF4371_RF_DIV_SEL(x)		FIELD_PREP(ADF4371_RF_DIV_SEL_MSK, x)
+
+/* ADF4371_REG25 */
+#define ADF4371_MUTE_LD_MSK		BIT(7)
+#define ADF4371_MUTE_LD(x)		FIELD_PREP(ADF4371_MUTE_LD_MSK, x)
+
+/* ADF4371_REG32 */
+#define ADF4371_TIMEOUT_MSK		GENMASK(1, 0)
+#define ADF4371_TIMEOUT(x)		FIELD_PREP(ADF4371_TIMEOUT_MSK, x)
+
+/* ADF4371_REG34 */
+#define ADF4371_VCO_ALC_TOUT_MSK	GENMASK(4, 0)
+#define ADF4371_VCO_ALC_TOUT(x)		FIELD_PREP(ADF4371_VCO_ALC_TOUT_MSK, x)
+
+/* Specifications */
+#define ADF4371_MIN_VCO_FREQ		4000000000ULL /* 4000 MHz */
+#define ADF4371_MAX_VCO_FREQ		8000000000ULL /* 8000 MHz */
+#define ADF4371_MAX_OUT_RF8_FREQ	ADF4371_MAX_VCO_FREQ /* Hz */
+#define ADF4371_MIN_OUT_RF8_FREQ	(ADF4371_MIN_VCO_FREQ / 64) /* Hz */
+#define ADF4371_MAX_OUT_RF16_FREQ	(ADF4371_MAX_VCO_FREQ * 2) /* Hz */
+#define ADF4371_MIN_OUT_RF16_FREQ	(ADF4371_MIN_VCO_FREQ * 2) /* Hz */
+#define ADF4371_MAX_OUT_RF32_FREQ	(ADF4371_MAX_VCO_FREQ * 4) /* Hz */
+#define ADF4371_MIN_OUT_RF32_FREQ	(ADF4371_MIN_VCO_FREQ * 4) /* Hz */
+
+#define ADF4371_MAX_FREQ_PFD		250000000UL /* Hz */
+#define ADF4371_MAX_FREQ_REFIN		600000000UL /* Hz */
+
+/* MOD1 is a 24-bit primary modulus with fixed value of 2^25 */
+#define ADF4371_MODULUS1		33554432ULL
+/* MOD2 is the programmable, 14-bit auxiliary fractional modulus */
+#define ADF4371_MAX_MODULUS2		BIT(14)
+
+#define ADF4371_CHECK_RANGE(freq, range) \
+	((freq > ADF4371_MAX_ ## range) || (freq < ADF4371_MIN_ ## range))
+
+enum {
+	ADF4371_FREQ,
+	ADF4371_POWER_DOWN,
+	ADF4371_CHANNEL_NAME
+};
+
+enum {
+	ADF4371_CH_RF8,
+	ADF4371_CH_RFAUX8,
+	ADF4371_CH_RF16,
+	ADF4371_CH_RF32
+};
+
+enum adf4371_variant {
+	ADF4371,
+	ADF4372
+};
+
+struct adf4371_pwrdown {
+	unsigned int reg;
+	unsigned int bit;
+};
+
+static const char * const adf4371_ch_names[] = {
+	"RF8x", "RFAUX8x", "RF16x", "RF32x"
+};
+
+static const struct adf4371_pwrdown adf4371_pwrdown_ch[4] = {
+	[ADF4371_CH_RF8] = { ADF4371_REG(0x25), 2 },
+	[ADF4371_CH_RFAUX8] = { ADF4371_REG(0x72), 3 },
+	[ADF4371_CH_RF16] = { ADF4371_REG(0x25), 3 },
+	[ADF4371_CH_RF32] = { ADF4371_REG(0x25), 4 },
+};
+
+static const struct reg_sequence adf4371_reg_defaults[] = {
+	{ ADF4371_REG(0x0),  0x18 },
+	{ ADF4371_REG(0x12), 0x40 },
+	{ ADF4371_REG(0x1E), 0x48 },
+	{ ADF4371_REG(0x20), 0x14 },
+	{ ADF4371_REG(0x22), 0x00 },
+	{ ADF4371_REG(0x23), 0x00 },
+	{ ADF4371_REG(0x24), 0x80 },
+	{ ADF4371_REG(0x25), 0x07 },
+	{ ADF4371_REG(0x27), 0xC5 },
+	{ ADF4371_REG(0x28), 0x83 },
+	{ ADF4371_REG(0x2C), 0x44 },
+	{ ADF4371_REG(0x2D), 0x11 },
+	{ ADF4371_REG(0x2E), 0x12 },
+	{ ADF4371_REG(0x2F), 0x94 },
+	{ ADF4371_REG(0x32), 0x04 },
+	{ ADF4371_REG(0x35), 0xFA },
+	{ ADF4371_REG(0x36), 0x30 },
+	{ ADF4371_REG(0x39), 0x07 },
+	{ ADF4371_REG(0x3A), 0x55 },
+	{ ADF4371_REG(0x3E), 0x0C },
+	{ ADF4371_REG(0x3F), 0x80 },
+	{ ADF4371_REG(0x40), 0x50 },
+	{ ADF4371_REG(0x41), 0x28 },
+	{ ADF4371_REG(0x47), 0xC0 },
+	{ ADF4371_REG(0x52), 0xF4 },
+	{ ADF4371_REG(0x70), 0x03 },
+	{ ADF4371_REG(0x71), 0x60 },
+	{ ADF4371_REG(0x72), 0x32 },
+};
+
+static const struct regmap_config adf4371_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 8,
+	.read_flag_mask = BIT(7),
+};
+
+struct adf4371_chip_info {
+	unsigned int num_channels;
+	const struct iio_chan_spec *channels;
+};
+
+struct adf4371_state {
+	struct spi_device *spi;
+	struct regmap *regmap;
+	struct clk *clkin;
+	/*
+	 * Lock for accessing device registers. Some operations require
+	 * multiple consecutive R/W operations, during which the device
+	 * shouldn't be interrupted. The buffers are also shared across
+	 * all operations so need to be protected on stand alone reads and
+	 * writes.
+	 */
+	struct mutex lock;
+	const struct adf4371_chip_info *chip_info;
+	unsigned long clkin_freq;
+	unsigned long fpfd;
+	unsigned int integer;
+	unsigned int fract1;
+	unsigned int fract2;
+	unsigned int mod2;
+	unsigned int rf_div_sel;
+	unsigned int ref_div_factor;
+	u8 buf[10] __aligned(IIO_DMA_MINALIGN);
+};
+
+static unsigned long long adf4371_pll_fract_n_get_rate(struct adf4371_state *st,
+						       u32 channel)
+{
+	unsigned long long val, tmp;
+	unsigned int ref_div_sel;
+
+	val = (((u64)st->integer * ADF4371_MODULUS1) + st->fract1) * st->fpfd;
+	tmp = (u64)st->fract2 * st->fpfd;
+	do_div(tmp, st->mod2);
+	val += tmp + ADF4371_MODULUS1 / 2;
+
+	if (channel == ADF4371_CH_RF8 || channel == ADF4371_CH_RFAUX8)
+		ref_div_sel = st->rf_div_sel;
+	else
+		ref_div_sel = 0;
+
+	do_div(val, ADF4371_MODULUS1 * (1 << ref_div_sel));
+
+	if (channel == ADF4371_CH_RF16)
+		val <<= 1;
+	else if (channel == ADF4371_CH_RF32)
+		val <<= 2;
+
+	return val;
+}
+
+static void adf4371_pll_fract_n_compute(unsigned long long vco,
+				       unsigned long long pfd,
+				       unsigned int *integer,
+				       unsigned int *fract1,
+				       unsigned int *fract2,
+				       unsigned int *mod2)
+{
+	unsigned long long tmp;
+	u32 gcd_div;
+
+	tmp = do_div(vco, pfd);
+	tmp = tmp * ADF4371_MODULUS1;
+	*fract2 = do_div(tmp, pfd);
+
+	*integer = vco;
+	*fract1 = tmp;
+
+	*mod2 = pfd;
+
+	while (*mod2 > ADF4371_MAX_MODULUS2) {
+		*mod2 >>= 1;
+		*fract2 >>= 1;
+	}
+
+	gcd_div = gcd(*fract2, *mod2);
+	*mod2 /= gcd_div;
+	*fract2 /= gcd_div;
+}
+
+static int adf4371_set_freq(struct adf4371_state *st, unsigned long long freq,
+			    unsigned int channel)
+{
+	u32 cp_bleed;
+	u8 int_mode = 0;
+	int ret;
+
+	switch (channel) {
+	case ADF4371_CH_RF8:
+	case ADF4371_CH_RFAUX8:
+		if (ADF4371_CHECK_RANGE(freq, OUT_RF8_FREQ))
+			return -EINVAL;
+
+		st->rf_div_sel = 0;
+
+		while (freq < ADF4371_MIN_VCO_FREQ) {
+			freq <<= 1;
+			st->rf_div_sel++;
+		}
+		break;
+	case ADF4371_CH_RF16:
+		/* ADF4371 RF16 8000...16000 MHz */
+		if (ADF4371_CHECK_RANGE(freq, OUT_RF16_FREQ))
+			return -EINVAL;
+
+		freq >>= 1;
+		break;
+	case ADF4371_CH_RF32:
+		/* ADF4371 RF32 16000...32000 MHz */
+		if (ADF4371_CHECK_RANGE(freq, OUT_RF32_FREQ))
+			return -EINVAL;
+
+		freq >>= 2;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	adf4371_pll_fract_n_compute(freq, st->fpfd, &st->integer, &st->fract1,
+				    &st->fract2, &st->mod2);
+	st->buf[0] = st->integer >> 8;
+	st->buf[1] = 0x40; /* REG12 default */
+	st->buf[2] = 0x00;
+	st->buf[3] = st->fract1 & 0xFF;
+	st->buf[4] = st->fract1 >> 8;
+	st->buf[5] = st->fract1 >> 16;
+	st->buf[6] = ADF4371_FRAC2WORD_L(st->fract2 & 0x7F) |
+		     ADF4371_FRAC1WORD(st->fract1 >> 24);
+	st->buf[7] = ADF4371_FRAC2WORD_H(st->fract2 >> 7);
+	st->buf[8] = st->mod2 & 0xFF;
+	st->buf[9] = ADF4371_MOD2WORD(st->mod2 >> 8);
+
+	ret = regmap_bulk_write(st->regmap, ADF4371_REG(0x11), st->buf, 10);
+	if (ret < 0)
+		return ret;
+	/*
+	 * The R counter allows the input reference frequency to be
+	 * divided down to produce the reference clock to the PFD
+	 */
+	ret = regmap_write(st->regmap, ADF4371_REG(0x1F), st->ref_div_factor);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(st->regmap, ADF4371_REG(0x24),
+				 ADF4371_RF_DIV_SEL_MSK,
+				 ADF4371_RF_DIV_SEL(st->rf_div_sel));
+	if (ret < 0)
+		return ret;
+
+	cp_bleed = DIV_ROUND_UP(400 * 1750, st->integer * 375);
+	cp_bleed = clamp(cp_bleed, 1U, 255U);
+	ret = regmap_write(st->regmap, ADF4371_REG(0x26), cp_bleed);
+	if (ret < 0)
+		return ret;
+	/*
+	 * Set to 1 when in INT mode (when FRAC1 = FRAC2 = 0),
+	 * and set to 0 when in FRAC mode.
+	 */
+	if (st->fract1 == 0 && st->fract2 == 0)
+		int_mode = 0x01;
+
+	ret = regmap_write(st->regmap, ADF4371_REG(0x2B), int_mode);
+	if (ret < 0)
+		return ret;
+
+	return regmap_write(st->regmap, ADF4371_REG(0x10), st->integer & 0xFF);
+}
+
+static ssize_t adf4371_read(struct iio_dev *indio_dev,
+			    uintptr_t private,
+			    const struct iio_chan_spec *chan,
+			    char *buf)
+{
+	struct adf4371_state *st = iio_priv(indio_dev);
+	unsigned long long val = 0;
+	unsigned int readval, reg, bit;
+	int ret;
+
+	switch ((u32)private) {
+	case ADF4371_FREQ:
+		val = adf4371_pll_fract_n_get_rate(st, chan->channel);
+		ret = regmap_read(st->regmap, ADF4371_REG(0x7C), &readval);
+		if (ret < 0)
+			break;
+
+		if (readval == 0x00) {
+			dev_dbg(&st->spi->dev, "PLL un-locked\n");
+			ret = -EBUSY;
+		}
+		break;
+	case ADF4371_POWER_DOWN:
+		reg = adf4371_pwrdown_ch[chan->channel].reg;
+		bit = adf4371_pwrdown_ch[chan->channel].bit;
+
+		ret = regmap_read(st->regmap, reg, &readval);
+		if (ret < 0)
+			break;
+
+		val = !(readval & BIT(bit));
+		break;
+	case ADF4371_CHANNEL_NAME:
+		return sprintf(buf, "%s\n", adf4371_ch_names[chan->channel]);
+	default:
+		ret = -EINVAL;
+		val = 0;
+		break;
+	}
+
+	return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
+}
+
+static ssize_t adf4371_write(struct iio_dev *indio_dev,
+			     uintptr_t private,
+			     const struct iio_chan_spec *chan,
+			     const char *buf, size_t len)
+{
+	struct adf4371_state *st = iio_priv(indio_dev);
+	unsigned long long freq;
+	bool power_down;
+	unsigned int bit, readval, reg;
+	int ret;
+
+	mutex_lock(&st->lock);
+	switch ((u32)private) {
+	case ADF4371_FREQ:
+		ret = kstrtoull(buf, 10, &freq);
+		if (ret)
+			break;
+
+		ret = adf4371_set_freq(st, freq, chan->channel);
+		break;
+	case ADF4371_POWER_DOWN:
+		ret = kstrtobool(buf, &power_down);
+		if (ret)
+			break;
+
+		reg = adf4371_pwrdown_ch[chan->channel].reg;
+		bit = adf4371_pwrdown_ch[chan->channel].bit;
+		ret = regmap_read(st->regmap, reg, &readval);
+		if (ret < 0)
+			break;
+
+		readval &= ~BIT(bit);
+		readval |= (!power_down << bit);
+
+		ret = regmap_write(st->regmap, reg, readval);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret ? ret : len;
+}
+
+#define _ADF4371_EXT_INFO(_name, _ident) { \
+		.name = _name, \
+		.read = adf4371_read, \
+		.write = adf4371_write, \
+		.private = _ident, \
+		.shared = IIO_SEPARATE, \
+}
+
+static const struct iio_chan_spec_ext_info adf4371_ext_info[] = {
+	/*
+	 * Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
+	 * values > 2^32 in order to support the entire frequency range
+	 * in Hz. Using scale is a bit ugly.
+	 */
+	_ADF4371_EXT_INFO("frequency", ADF4371_FREQ),
+	_ADF4371_EXT_INFO("powerdown", ADF4371_POWER_DOWN),
+	_ADF4371_EXT_INFO("name", ADF4371_CHANNEL_NAME),
+	{ },
+};
+
+#define ADF4371_CHANNEL(index) { \
+		.type = IIO_ALTVOLTAGE, \
+		.output = 1, \
+		.channel = index, \
+		.ext_info = adf4371_ext_info, \
+		.indexed = 1, \
+	}
+
+static const struct iio_chan_spec adf4371_chan[] = {
+	ADF4371_CHANNEL(ADF4371_CH_RF8),
+	ADF4371_CHANNEL(ADF4371_CH_RFAUX8),
+	ADF4371_CHANNEL(ADF4371_CH_RF16),
+	ADF4371_CHANNEL(ADF4371_CH_RF32),
+};
+
+static const struct adf4371_chip_info adf4371_chip_info[] = {
+	[ADF4371] = {
+		.channels = adf4371_chan,
+		.num_channels = 4,
+	},
+	[ADF4372] = {
+		.channels = adf4371_chan,
+		.num_channels = 3,
+	}
+};
+
+static int adf4371_reg_access(struct iio_dev *indio_dev,
+			      unsigned int reg,
+			      unsigned int writeval,
+			      unsigned int *readval)
+{
+	struct adf4371_state *st = iio_priv(indio_dev);
+
+	if (readval)
+		return regmap_read(st->regmap, reg, readval);
+	else
+		return regmap_write(st->regmap, reg, writeval);
+}
+
+static const struct iio_info adf4371_info = {
+	.debugfs_reg_access = &adf4371_reg_access,
+};
+
+static int adf4371_setup(struct adf4371_state *st)
+{
+	unsigned int synth_timeout = 2, timeout = 1, vco_alc_timeout = 1;
+	unsigned int vco_band_div, tmp;
+	int ret;
+
+	/* Perform a software reset */
+	ret = regmap_write(st->regmap, ADF4371_REG(0x0), ADF4371_RESET_CMD);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_multi_reg_write(st->regmap, adf4371_reg_defaults,
+				     ARRAY_SIZE(adf4371_reg_defaults));
+	if (ret < 0)
+		return ret;
+
+	/* Mute to Lock Detect */
+	if (device_property_read_bool(&st->spi->dev, "adi,mute-till-lock-en")) {
+		ret = regmap_update_bits(st->regmap, ADF4371_REG(0x25),
+					 ADF4371_MUTE_LD_MSK,
+					 ADF4371_MUTE_LD(1));
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set address in ascending order, so the bulk_write() will work */
+	ret = regmap_update_bits(st->regmap, ADF4371_REG(0x0),
+				 ADF4371_ADDR_ASC_MSK | ADF4371_ADDR_ASC_R_MSK,
+				 ADF4371_ADDR_ASC(1) | ADF4371_ADDR_ASC_R(1));
+	if (ret < 0)
+		return ret;
+	/*
+	 * Calculate and maximize PFD frequency
+	 * fPFD = REFIN × ((1 + D)/(R × (1 + T)))
+	 * Where D is the REFIN doubler bit, T is the reference divide by 2,
+	 * R is the reference division factor
+	 * TODO: it is assumed D and T equal 0.
+	 */
+	do {
+		st->ref_div_factor++;
+		st->fpfd = st->clkin_freq / st->ref_div_factor;
+	} while (st->fpfd > ADF4371_MAX_FREQ_PFD);
+
+	/* Calculate Timeouts */
+	vco_band_div = DIV_ROUND_UP(st->fpfd, 2400000U);
+
+	tmp = DIV_ROUND_CLOSEST(st->fpfd, 1000000U);
+	do {
+		timeout++;
+		if (timeout > 1023) {
+			timeout = 2;
+			synth_timeout++;
+		}
+	} while (synth_timeout * 1024 + timeout <= 20 * tmp);
+
+	do {
+		vco_alc_timeout++;
+	} while (vco_alc_timeout * 1024 - timeout <= 50 * tmp);
+
+	st->buf[0] = vco_band_div;
+	st->buf[1] = timeout & 0xFF;
+	st->buf[2] = ADF4371_TIMEOUT(timeout >> 8) | 0x04;
+	st->buf[3] = synth_timeout;
+	st->buf[4] = ADF4371_VCO_ALC_TOUT(vco_alc_timeout);
+
+	return regmap_bulk_write(st->regmap, ADF4371_REG(0x30), st->buf, 5);
+}
+
+static int adf4371_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct iio_dev *indio_dev;
+	struct adf4371_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, &adf4371_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+	st->spi = spi;
+	st->regmap = regmap;
+	mutex_init(&st->lock);
+
+	st->chip_info = &adf4371_chip_info[id->driver_data];
+	indio_dev->name = id->name;
+	indio_dev->info = &adf4371_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+
+	st->clkin = devm_clk_get_enabled(&spi->dev, "clkin");
+	if (IS_ERR(st->clkin))
+		return PTR_ERR(st->clkin);
+
+	st->clkin_freq = clk_get_rate(st->clkin);
+
+	ret = adf4371_setup(st);
+	if (ret < 0) {
+		dev_err(&spi->dev, "ADF4371 setup failed\n");
+		return ret;
+	}
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id adf4371_id_table[] = {
+	{ "adf4371", ADF4371 },
+	{ "adf4372", ADF4372 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, adf4371_id_table);
+
+static const struct of_device_id adf4371_of_match[] = {
+	{ .compatible = "adi,adf4371" },
+	{ .compatible = "adi,adf4372" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, adf4371_of_match);
+
+static struct spi_driver adf4371_driver = {
+	.driver = {
+		.name = "adf4371",
+		.of_match_table = adf4371_of_match,
+	},
+	.probe = adf4371_probe,
+	.id_table = adf4371_id_table,
+};
+module_spi_driver(adf4371_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADF4371 SPI PLL");
+MODULE_LICENSE("GPL");