@@ -5,4 +5,14 @@
menu "Filters"
+config ADMV8818
+ tristate "Analog Devices ADMV8818 High-Pass and Low-Pass Filter"
+ depends on SPI && COMMON_CLK && 64BIT
+ help
+ Say yes here to build support for Analog Devices ADMV8818
+ 2 GHz to 18 GHz, Digitally Tunable, High-Pass and Low-Pass Filter.
+
+ To compile this driver as a module, choose M here: the
+ modiule will be called admv8818.
+
endmenu
@@ -4,3 +4,4 @@
#
# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_ADMV8818) += admv8818.o
new file mode 100644
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ADMV8818 driver
+ *
+ * Copyright 2021 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/sysfs.h>
+#include <linux/units.h>
+
+/* ADMV8818 Register Map */
+#define ADMV8818_REG_SPI_CONFIG_A 0x0
+#define ADMV8818_REG_SPI_CONFIG_B 0x1
+#define ADMV8818_REG_CHIPTYPE 0x3
+#define ADMV8818_REG_PRODUCT_ID_L 0x4
+#define ADMV8818_REG_PRODUCT_ID_H 0x5
+#define ADMV8818_REG_FAST_LATCH_POINTER 0x10
+#define ADMV8818_REG_FAST_LATCH_STOP 0x11
+#define ADMV8818_REG_FAST_LATCH_START 0x12
+#define ADMV8818_REG_FAST_LATCH_DIRECTION 0x13
+#define ADMV8818_REG_FAST_LATCH_STATE 0x14
+#define ADMV8818_REG_WR0_SW 0x20
+#define ADMV8818_REG_WR0_FILTER 0x21
+#define ADMV8818_REG_WR1_SW 0x22
+#define ADMV8818_REG_WR1_FILTER 0x23
+#define ADMV8818_REG_WR2_SW 0x24
+#define ADMV8818_REG_WR2_FILTER 0x25
+#define ADMV8818_REG_WR3_SW 0x26
+#define ADMV8818_REG_WR3_FILTER 0x27
+#define ADMV8818_REG_WR4_SW 0x28
+#define ADMV8818_REG_WR4_FILTER 0x29
+#define ADMV8818_REG_LUT0_SW 0x100
+#define ADMV8818_REG_LUT0_FILTER 0x101
+#define ADMV8818_REG_LUT127_SW 0x1FE
+#define ADMV8818_REG_LUT127_FILTER 0x1FF
+
+/* ADMV8818_REG_SPI_CONFIG_A Map */
+#define ADMV8818_SOFTRESET_N_MSK BIT(7)
+#define ADMV8818_LSB_FIRST_N_MSK BIT(6)
+#define ADMV8818_ENDIAN_N_MSK BIT(5)
+#define ADMV8818_SDOACTIVE_N_MSK BIT(4)
+#define ADMV8818_SDOACTIVE_MSK BIT(3)
+#define ADMV8818_ENDIAN_MSK BIT(2)
+#define ADMV8818_LSBFIRST_MSK BIT(1)
+#define ADMV8818_SOFTRESET_MSK BIT(0)
+
+/* ADMV8818_REG_SPI_CONFIG_B Map */
+#define ADMV8818_SINGLE_INSTRUCTION_MSK BIT(7)
+#define ADMV8818_CSB_STALL_MSK BIT(6)
+#define ADMV8818_MASTER_SLAVE_RB_MSK BIT(5)
+#define ADMV8818_MASTER_SLAVE_TRANSFER_MSK BIT(0)
+
+/* ADMV8818_REG_WR0_SW Map */
+#define ADMV8818_SW_IN_SET_WR0_MSK BIT(7)
+#define ADMV8818_SW_OUT_SET_WR0_MSK BIT(6)
+#define ADMV8818_SW_IN_WR0_MSK GENMASK(5, 3)
+#define ADMV8818_SW_OUT_WR0_MSK GENMASK(2, 0)
+
+/* ADMV8818_REG_WR0_FILTER Map */
+#define ADMV8818_HPF_WR0_MSK GENMASK(7, 4)
+#define ADMV8818_LPF_WR0_MSK GENMASK(3, 0)
+
+enum {
+ ADMV8818_BW_FREQ,
+ ADMV8818_CENTER_FREQ
+};
+
+enum {
+ ADMV8818_AUTO_MODE,
+ ADMV8818_MANUAL_MODE,
+};
+
+struct admv8818_state {
+ struct spi_device *spi;
+ struct regmap *regmap;
+ struct clk *clkin;
+ struct notifier_block nb;
+ /* Protect against concurrent accesses to the device and data content*/
+ struct mutex lock;
+ unsigned int filter_mode;
+ unsigned int freq_scale;
+ u64 cf_hz;
+};
+
+static const unsigned long long freq_range_hpf[4][2] = {
+ {1750000000ULL, 3550000000ULL},
+ {3400000000ULL, 7250000000ULL},
+ {6600000000, 12000000000},
+ {12500000000, 19900000000}
+};
+
+static const unsigned long long freq_range_lpf[4][2] = {
+ {2050000000ULL, 3850000000ULL},
+ {3350000000ULL, 7250000000ULL},
+ {7000000000, 13000000000},
+ {12550000000, 18500000000}
+};
+
+static const struct regmap_config admv8818_regmap_config = {
+ .reg_bits = 16,
+ .val_bits = 8,
+ .read_flag_mask = 0x80,
+ .max_register = 0x1FF,
+};
+
+static const char * const admv8818_modes[] = {
+ [0] = "auto",
+ [1] = "manual"
+};
+
+static int __admv8818_hpf_select(struct admv8818_state *st, u64 freq)
+{
+ unsigned int hpf_step = 0, hpf_band = 0, i, j;
+ u64 freq_step;
+ int ret;
+
+ if (freq < freq_range_hpf[0][0])
+ goto hpf_write;
+
+ if (freq > freq_range_hpf[3][1]) {
+ hpf_step = 15;
+ hpf_band = 4;
+
+ goto hpf_write;
+ }
+
+ for (i = 0; i < 4; i++) {
+ freq_step = div_u64((freq_range_hpf[i][1] -
+ freq_range_hpf[i][0]), 15);
+
+ if (freq > freq_range_hpf[i][0] &&
+ (freq < freq_range_hpf[i][1] + freq_step)) {
+ hpf_band = i + 1;
+
+ for (j = 1; j <= 16; j++) {
+ if (freq < (freq_range_hpf[i][0] + (freq_step * j))) {
+ hpf_step = j - 1;
+ break;
+ }
+ }
+ break;
+ }
+ }
+
+ /* Close HPF frequency gap between 12 and 12.5 GHz */
+ if (freq >= 12000 * HZ_PER_MHZ && freq <= 12500 * HZ_PER_MHZ) {
+ hpf_band = 3;
+ hpf_step = 15;
+ }
+
+hpf_write:
+ ret = regmap_update_bits(st->regmap, ADMV8818_REG_WR0_SW,
+ ADMV8818_SW_IN_SET_WR0_MSK |
+ ADMV8818_SW_IN_WR0_MSK,
+ FIELD_PREP(ADMV8818_SW_IN_SET_WR0_MSK, 1) |
+ FIELD_PREP(ADMV8818_SW_IN_WR0_MSK, hpf_band));
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(st->regmap, ADMV8818_REG_WR0_FILTER,
+ ADMV8818_HPF_WR0_MSK,
+ FIELD_PREP(ADMV8818_HPF_WR0_MSK, hpf_step));
+}
+
+static int admv8818_hpf_select(struct admv8818_state *st, u64 freq)
+{
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __admv8818_hpf_select(st, freq);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int __admv8818_lpf_select(struct admv8818_state *st, u64 freq)
+{
+ unsigned int lpf_step = 0, lpf_band = 0, i, j;
+ u64 freq_step;
+ int ret;
+
+ if (freq > freq_range_lpf[3][1])
+ goto lpf_write;
+
+ if (freq < freq_range_lpf[0][0]) {
+ lpf_band = 1;
+
+ goto lpf_write;
+ }
+
+ for (i = 0; i < 4; i++) {
+ if (freq > freq_range_lpf[i][0] && freq < freq_range_lpf[i][1]) {
+ lpf_band = i + 1;
+ freq_step = div_u64((freq_range_lpf[i][1] - freq_range_lpf[i][0]), 15);
+
+ for (j = 0; j <= 15; j++) {
+ if (freq < (freq_range_lpf[i][0] + (freq_step * j))) {
+ lpf_step = j;
+ break;
+ }
+ }
+ break;
+ }
+ }
+
+lpf_write:
+ ret = regmap_update_bits(st->regmap, ADMV8818_REG_WR0_SW,
+ ADMV8818_SW_OUT_SET_WR0_MSK |
+ ADMV8818_SW_OUT_WR0_MSK,
+ FIELD_PREP(ADMV8818_SW_OUT_SET_WR0_MSK, 1) |
+ FIELD_PREP(ADMV8818_SW_OUT_WR0_MSK, lpf_band));
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(st->regmap, ADMV8818_REG_WR0_FILTER,
+ ADMV8818_LPF_WR0_MSK,
+ FIELD_PREP(ADMV8818_LPF_WR0_MSK, lpf_step));
+}
+
+static int admv8818_lpf_select(struct admv8818_state *st, u64 freq)
+{
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __admv8818_lpf_select(st, freq);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int admv8818_rfin_band_select(struct admv8818_state *st)
+{
+ int ret;
+
+ st->cf_hz = clk_get_rate(st->clkin);
+
+ mutex_lock(&st->lock);
+
+ ret = __admv8818_hpf_select(st, st->cf_hz);
+ if (ret)
+ goto exit;
+
+ ret = __admv8818_lpf_select(st, st->cf_hz);
+exit:
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
+static int __admv8818_read_hpf_freq(struct admv8818_state *st, u64 *hpf_freq)
+{
+ unsigned int data, hpf_band, hpf_state;
+ int ret;
+
+ ret = regmap_read(st->regmap, ADMV8818_REG_WR0_SW, &data);
+ if (ret)
+ return ret;
+
+ hpf_band = FIELD_GET(ADMV8818_SW_IN_WR0_MSK, data);
+ if (!hpf_band) {
+ *hpf_freq = 0;
+ return ret;
+ }
+
+ ret = regmap_read(st->regmap, ADMV8818_REG_WR0_FILTER, &data);
+ if (ret)
+ return ret;
+
+ hpf_state = FIELD_GET(ADMV8818_HPF_WR0_MSK, data);
+
+ *hpf_freq = div_u64(freq_range_hpf[hpf_band - 1][1] - freq_range_hpf[hpf_band - 1][0], 15);
+ *hpf_freq = freq_range_hpf[hpf_band - 1][0] + (*hpf_freq * hpf_state);
+
+ return ret;
+}
+
+static int admv8818_read_hpf_freq(struct admv8818_state *st, u64 *hpf_freq)
+{
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __admv8818_read_hpf_freq(st, hpf_freq);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int __admv8818_read_lpf_freq(struct admv8818_state *st, u64 *lpf_freq)
+{
+ unsigned int data, lpf_band, lpf_state;
+ int ret;
+
+ ret = regmap_read(st->regmap, ADMV8818_REG_WR0_SW, &data);
+ if (ret)
+ return ret;
+
+ lpf_band = FIELD_GET(ADMV8818_SW_OUT_WR0_MSK, data);
+ if (!lpf_band) {
+ *lpf_freq = 0;
+ return ret;
+ }
+
+ ret = regmap_read(st->regmap, ADMV8818_REG_WR0_FILTER, &data);
+ if (ret)
+ return ret;
+
+ lpf_state = FIELD_GET(ADMV8818_LPF_WR0_MSK, data);
+
+ *lpf_freq = div_u64(freq_range_lpf[lpf_band - 1][1] - freq_range_lpf[lpf_band - 1][0], 15);
+ *lpf_freq = freq_range_lpf[lpf_band - 1][0] + (*lpf_freq * lpf_state);
+
+ return ret;
+}
+
+static int admv8818_read_lpf_freq(struct admv8818_state *st, u64 *lpf_freq)
+{
+ int ret;
+
+ mutex_lock(&st->lock);
+ ret = __admv8818_read_lpf_freq(st, lpf_freq);
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int admv8818_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long info)
+{
+ struct admv8818_state *st = iio_priv(indio_dev);
+
+ u64 freq = (u64)val * st->freq_scale;
+
+ switch (info) {
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ return admv8818_lpf_select(st, freq);
+ case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+ return admv8818_hpf_select(st, freq);
+ case IIO_CHAN_INFO_SCALE:
+ st->freq_scale = val;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int admv8818_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long info)
+{
+ struct admv8818_state *st = iio_priv(indio_dev);
+ int ret;
+ u64 freq;
+
+ switch (info) {
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ ret = admv8818_read_lpf_freq(st, &freq);
+ if (ret)
+ return ret;
+
+ *val = div_u64(freq, st->freq_scale);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+ ret = admv8818_read_hpf_freq(st, &freq);
+ if (ret)
+ return ret;
+
+ *val = div_u64(freq, st->freq_scale);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->freq_scale;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int admv8818_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg,
+ unsigned int write_val,
+ unsigned int *read_val)
+{
+ struct admv8818_state *st = iio_priv(indio_dev);
+
+ if (read_val)
+ return regmap_read(st->regmap, reg, read_val);
+ else
+ return regmap_write(st->regmap, reg, write_val);
+}
+
+static int admv8818_get_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct admv8818_state *st = iio_priv(indio_dev);
+
+ return st->filter_mode;
+}
+
+static int admv8818_set_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int mode)
+{
+ struct admv8818_state *st = iio_priv(indio_dev);
+ int ret = 0;
+
+ switch (mode) {
+ case ADMV8818_AUTO_MODE:
+ if (st->filter_mode && st->clkin) {
+ ret = clk_prepare_enable(st->clkin);
+ if (ret)
+ return ret;
+
+ ret = clk_notifier_register(st->clkin, &st->nb);
+ if (ret)
+ return ret;
+ } else {
+ return ret;
+ }
+
+ break;
+ case ADMV8818_MANUAL_MODE:
+ if (st->filter_mode == 0 && st->clkin) {
+ clk_disable_unprepare(st->clkin);
+
+ ret = clk_notifier_unregister(st->clkin, &st->nb);
+ if (ret)
+ return ret;
+ } else {
+ return ret;
+ }
+
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ st->filter_mode = mode;
+
+ return ret;
+}
+
+static const struct iio_info admv8818_info = {
+ .write_raw = admv8818_write_raw,
+ .read_raw = admv8818_read_raw,
+ .debugfs_reg_access = &admv8818_reg_access,
+};
+
+static const struct iio_enum admv8818_mode_enum = {
+ .items = admv8818_modes,
+ .num_items = ARRAY_SIZE(admv8818_modes),
+ .get = admv8818_get_mode,
+ .set = admv8818_set_mode,
+};
+
+static const struct iio_chan_spec_ext_info admv8818_ext_info[] = {
+ IIO_ENUM("filter_mode", IIO_SHARED_BY_ALL, &admv8818_mode_enum),
+ IIO_ENUM_AVAILABLE("filter_mode", IIO_SHARED_BY_ALL, &admv8818_mode_enum),
+ { },
+};
+
+#define ADMV8818_CHAN(_channel) { \
+ .type = IIO_ALTVOLTAGE, \
+ .output = 1, \
+ .indexed = 1, \
+ .channel = _channel, \
+ .info_mask_separate = \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
+ BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY) | \
+ BIT(IIO_CHAN_INFO_SCALE) \
+}
+
+#define ADMV8818_CHAN_BW_CF(_channel, _admv8818_ext_info) { \
+ .type = IIO_ALTVOLTAGE, \
+ .output = 1, \
+ .indexed = 1, \
+ .channel = _channel, \
+ .ext_info = _admv8818_ext_info, \
+}
+
+static const struct iio_chan_spec admv8818_channels[] = {
+ ADMV8818_CHAN(0),
+ ADMV8818_CHAN_BW_CF(0, admv8818_ext_info),
+};
+
+static int admv8818_freq_change(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct admv8818_state *st = container_of(nb, struct admv8818_state, nb);
+
+ if (action == POST_RATE_CHANGE)
+ return notifier_from_errno(admv8818_rfin_band_select(st));
+
+ return NOTIFY_OK;
+}
+
+static void admv8818_clk_notifier_unreg(void *data)
+{
+ struct admv8818_state *st = data;
+
+ if (st->filter_mode == 0)
+ clk_notifier_unregister(st->clkin, &st->nb);
+}
+
+static void admv8818_clk_disable(void *data)
+{
+ struct admv8818_state *st = data;
+
+ if (st->filter_mode == 0)
+ clk_disable_unprepare(st->clkin);
+}
+
+static int admv8818_init(struct admv8818_state *st)
+{
+ int ret;
+ struct spi_device *spi = st->spi;
+ unsigned int chip_id;
+
+ ret = regmap_update_bits(st->regmap, ADMV8818_REG_SPI_CONFIG_A,
+ ADMV8818_SOFTRESET_N_MSK |
+ ADMV8818_SOFTRESET_MSK,
+ FIELD_PREP(ADMV8818_SOFTRESET_N_MSK, 1) |
+ FIELD_PREP(ADMV8818_SOFTRESET_MSK, 1));
+ if (ret) {
+ dev_err(&spi->dev, "ADMV8818 Soft Reset failed.\n");
+ return ret;
+ }
+
+ ret = regmap_update_bits(st->regmap, ADMV8818_REG_SPI_CONFIG_A,
+ ADMV8818_SDOACTIVE_N_MSK |
+ ADMV8818_SDOACTIVE_MSK,
+ FIELD_PREP(ADMV8818_SDOACTIVE_N_MSK, 1) |
+ FIELD_PREP(ADMV8818_SDOACTIVE_MSK, 1));
+ if (ret) {
+ dev_err(&spi->dev, "ADMV8818 SDO Enable failed.\n");
+ return ret;
+ }
+
+ ret = regmap_read(st->regmap, ADMV8818_REG_CHIPTYPE, &chip_id);
+ if (ret) {
+ dev_err(&spi->dev, "ADMV8818 Chip ID read failed.\n");
+ return ret;
+ }
+
+ if (chip_id != 0x1) {
+ dev_err(&spi->dev, "ADMV8818 Invalid Chip ID.\n");
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(st->regmap, ADMV8818_REG_SPI_CONFIG_B,
+ ADMV8818_SINGLE_INSTRUCTION_MSK,
+ FIELD_PREP(ADMV8818_SINGLE_INSTRUCTION_MSK, 1));
+ if (ret) {
+ dev_err(&spi->dev, "ADMV8818 Single Instruction failed.\n");
+ return ret;
+ }
+
+ st->freq_scale = HZ_PER_MHZ;
+
+ if (st->clkin)
+ return admv8818_rfin_band_select(st);
+ else
+ return 0;
+}
+
+static int admv8818_clk_setup(struct admv8818_state *st)
+{
+ struct spi_device *spi = st->spi;
+ int ret;
+
+ st->clkin = devm_clk_get_optional(&spi->dev, "rf_in");
+ if (IS_ERR(st->clkin))
+ return dev_err_probe(&spi->dev, PTR_ERR(st->clkin),
+ "failed to get the input clock\n");
+ else if (!st->clkin)
+ return 0;
+
+ ret = clk_prepare_enable(st->clkin);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, admv8818_clk_disable, st);
+ if (ret)
+ return ret;
+
+ st->nb.notifier_call = admv8818_freq_change;
+ ret = clk_notifier_register(st->clkin, &st->nb);
+ if (ret < 0)
+ return ret;
+
+ return devm_add_action_or_reset(&spi->dev, admv8818_clk_notifier_unreg, st);
+}
+
+static int admv8818_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct regmap *regmap;
+ struct admv8818_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ regmap = devm_regmap_init_spi(spi, &admv8818_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ st = iio_priv(indio_dev);
+ st->regmap = regmap;
+
+ indio_dev->info = &admv8818_info;
+ indio_dev->name = "admv8818";
+ indio_dev->channels = admv8818_channels;
+ indio_dev->num_channels = ARRAY_SIZE(admv8818_channels);
+
+ st->spi = spi;
+
+ ret = admv8818_clk_setup(st);
+ if (ret)
+ return ret;
+
+ mutex_init(&st->lock);
+
+ ret = admv8818_init(st);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id admv8818_id[] = {
+ { "admv8818", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, admv8818_id);
+
+static const struct of_device_id admv8818_of_match[] = {
+ { .compatible = "adi,admv8818" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, admv8818_of_match);
+
+static struct spi_driver admv8818_driver = {
+ .driver = {
+ .name = "admv8818",
+ .of_match_table = admv8818_of_match,
+ },
+ .probe = admv8818_probe,
+ .id_table = admv8818_id,
+};
+module_spi_driver(admv8818_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
+MODULE_DESCRIPTION("Analog Devices ADMV8818");
+MODULE_LICENSE("GPL v2");
The ADMV8818-EP is a fully monolithic microwave integrated circuit (MMIC) that features a digitally selectable frequency of operation. The device features four independently controlled high- pass filters (HPFs) and four independently controlled low-pass filters (LPFs) that span the 2 GHz to 18 GHz frequency range. Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/admv8818-ep.pdf Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com> --- changes in v2: - use enum for filter modes - remove bandwidth/center frequency related implementations drivers/iio/filter/Kconfig | 10 + drivers/iio/filter/Makefile | 1 + drivers/iio/filter/admv8818.c | 666 ++++++++++++++++++++++++++++++++++ 3 files changed, 677 insertions(+) create mode 100644 drivers/iio/filter/admv8818.c