Messages in this thread Patch in this message |  | | From | Alexis Czezar Torreno <> | | Date | Wed, 1 Apr 2026 18:20:04 +0800 | | Subject | [PATCH v4 2/2] iio: dac: ad5706r: Add support for AD5706R DAC |
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Add support for the Analog Devices AD5706R, a 4-channel 16-bit current output digital-to-analog converter with SPI interface.
Features: - 4 independent DAC channels - Hardware and software LDAC trigger - Configurable output range - PWM-based LDAC control - Dither and toggle modes - Dynamically configurable SPI speed
Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
--- Changes since v1: - Removed PWM, GPIO, clock generator, debugfs, regmap, IIO_BUFFER - Removed all custom ext_info sysfs attributes - Simplified to basic raw read/write and read-only scale - SPI read/write can handle multibyte registers --- --- MAINTAINERS | 1 + drivers/iio/dac/Kconfig | 10 ++ drivers/iio/dac/Makefile | 1 + drivers/iio/dac/ad5706r.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 256 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS index 17a3d2d45fccb9cd3c93fd35666fb85d17d53cde..3d7bd98b4d1b55836e40687a9a3ac9f4935a8acb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1502,6 +1502,7 @@ L: linux-iio@vger.kernel.org S: Supported W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/dac/adi,ad5706r.yaml +F: drivers/iio/dac/ad5706r.c ANALOG DEVICES INC AD7091R DRIVER M: Marcelo Schmitt <marcelo.schmitt@analog.com> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig index db9f5c711b3df90641f017652fbbef594cc1627d..8ccbdf6dfbca8640a47bf05b4afc6b4bf90a7e26 100644 --- a/drivers/iio/dac/Kconfig +++ b/drivers/iio/dac/Kconfig @@ -178,6 +178,16 @@ config AD5624R_SPI Say yes here to build support for Analog Devices AD5624R, AD5644R and AD5664R converters (DAC). This driver uses the common SPI interface. +config AD5706R + tristate "Analog Devices AD5706R DAC driver" + depends on SPI + help + Say yes here to build support for Analog Devices AD5706R 4-channel, + 16-bit current output DAC. + + To compile this driver as a module, choose M here: the + module will be called ad5706r. + config AD9739A tristate "Analog Devices AD9739A RF DAC spi driver" depends on SPI diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile index 2a80bbf4e80ad557da79ed916027cedff286984b..0034317984985035f7987a744899924bfd4612e3 100644 --- a/drivers/iio/dac/Makefile +++ b/drivers/iio/dac/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_AD5449) += ad5449.o obj-$(CONFIG_AD5592R_BASE) += ad5592r-base.o obj-$(CONFIG_AD5592R) += ad5592r.o obj-$(CONFIG_AD5593R) += ad5593r.o +obj-$(CONFIG_AD5706R) += ad5706r.o obj-$(CONFIG_AD5755) += ad5755.o obj-$(CONFIG_AD5758) += ad5758.o obj-$(CONFIG_AD5761) += ad5761.o diff --git a/drivers/iio/dac/ad5706r.c b/drivers/iio/dac/ad5706r.c new file mode 100644 index 0000000000000000000000000000000000000000..c8c7b7b966dcfef90ecbcbe91170bf84ca609179 --- /dev/null +++ b/drivers/iio/dac/ad5706r.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AD5706R 16-bit Current Output Digital to Analog Converter + * + * Copyright 2026 Analog Devices Inc. + */ + +#include <linux/array_size.h> +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/iio/iio.h> +#include <linux/minmax.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/spi/spi.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/unaligned.h> + +/* SPI frame layout */ +#define AD5706R_RD_MASK BIT(15) +#define AD5706R_ADDR_MASK GENMASK(11, 0) + +/* Registers */ +#define AD5706R_REG_DAC_INPUT_A_CH(x) (0x60 + ((x) * 2)) +#define AD5706R_REG_DAC_DATA_READBACK_CH(x) (0x68 + ((x) * 2)) + +#define AD5706R_DAC_RESOLUTION 16 +#define AD5706R_DAC_MAX_CODE BIT(16) +#define AD5706R_MULTIBYTE_REG_START 0x14 +#define AD5706R_MULTIBYTE_REG_END 0x71 +#define AD5706R_MAX_REG 0x77 +#define AD5706R_SINGLE_BYTE_LEN 1 +#define AD5706R_DOUBLE_BYTE_LEN 2 + +struct ad5706r_state { + struct spi_device *spi; + struct regmap *regmap; + + u8 tx_buf[4] __aligned(ARCH_DMA_MINALIGN); + u8 rx_buf[4]; +}; + +static int ad5706r_reg_len(unsigned int reg) +{ + if (reg >= AD5706R_MULTIBYTE_REG_START && reg <= AD5706R_MULTIBYTE_REG_END) + return AD5706R_DOUBLE_BYTE_LEN; + + return AD5706R_SINGLE_BYTE_LEN; +} + +static int ad5706r_regmap_write(void *context, const void *data, size_t count) +{ + struct ad5706r_state *st = context; + unsigned int num_bytes; + u16 reg; + + reg = get_unaligned_be16(data); + num_bytes = ad5706r_reg_len(reg); + + struct spi_transfer xfer = { + .tx_buf = st->tx_buf, + .len = num_bytes + 2, + }; + + memcpy(st->tx_buf, data, count); + + /* For single byte, copy the data to the correct position */ + if (num_bytes == AD5706R_SINGLE_BYTE_LEN) + st->tx_buf[2] = st->tx_buf[3]; + + return spi_sync_transfer(st->spi, &xfer, 1); +} + +static int ad5706r_regmap_read(void *context, const void *reg_buf, + size_t reg_size, void *val_buf, size_t val_size) +{ + struct ad5706r_state *st = context; + unsigned int num_bytes; + u16 reg, cmd; + int ret; + + reg = get_unaligned_be16(reg_buf); + num_bytes = ad5706r_reg_len(reg); + + /* Full duplex, device responds immediately after command */ + struct spi_transfer xfer = { + .tx_buf = st->tx_buf, + .rx_buf = st->rx_buf, + .len = 2 + num_bytes, + }; + + cmd = AD5706R_RD_MASK | (reg & AD5706R_ADDR_MASK); + put_unaligned_be16(cmd, st->tx_buf); + memset(st->tx_buf + 2, 0, num_bytes); + + ret = spi_sync_transfer(st->spi, &xfer, 1); + if (ret) + return ret; + + /* Ignore the first two bytes (echo during command) */ + if (num_bytes == AD5706R_SINGLE_BYTE_LEN) + put_unaligned_be16(st->rx_buf[2], val_buf); + else + memcpy(val_buf, st->rx_buf + 2, num_bytes); + + return 0; +} + +static int ad5706r_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct ad5706r_state *st = iio_priv(indio_dev); + unsigned int reg, reg_val; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + reg = AD5706R_REG_DAC_DATA_READBACK_CH(chan->channel); + ret = regmap_read(st->regmap, reg, ®_val); + if (ret) + return ret; + + *val = reg_val; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 50; + *val2 = AD5706R_DAC_RESOLUTION; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static int ad5706r_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct ad5706r_state *st = iio_priv(indio_dev); + unsigned int reg; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (!in_range(val, 0, AD5706R_DAC_MAX_CODE)) + return -EINVAL; + + reg = AD5706R_REG_DAC_INPUT_A_CH(chan->channel); + return regmap_write(st->regmap, reg, val); + default: + return -EINVAL; + } +} + +static const struct regmap_bus ad5706r_regmap_bus = { + .write = ad5706r_regmap_write, + .read = ad5706r_regmap_read, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, +}; + +static const struct regmap_config ad5706r_regmap_config = { + .reg_bits = 16, + .val_bits = 16, + .max_register = AD5706R_MAX_REG, +}; + +static const struct iio_info ad5706r_info = { + .read_raw = ad5706r_read_raw, + .write_raw = ad5706r_write_raw, +}; + +#define AD5706R_CHAN(_channel) { \ + .type = IIO_CURRENT, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .output = 1, \ + .indexed = 1, \ + .channel = _channel, \ +} + +static const struct iio_chan_spec ad5706r_channels[] = { + AD5706R_CHAN(0), + AD5706R_CHAN(1), + AD5706R_CHAN(2), + AD5706R_CHAN(3), +}; + +static int ad5706r_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct ad5706r_state *st; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + st->regmap = devm_regmap_init(&spi->dev, &ad5706r_regmap_bus, + st, &ad5706r_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(&spi->dev, PTR_ERR(st->regmap), + "Failed to init regmap"); + + indio_dev->name = "ad5706r"; + indio_dev->info = &ad5706r_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ad5706r_channels; + indio_dev->num_channels = ARRAY_SIZE(ad5706r_channels); + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct of_device_id ad5706r_of_match[] = { + { .compatible = "adi,ad5706r" }, + { } +}; +MODULE_DEVICE_TABLE(of, ad5706r_of_match); + +static const struct spi_device_id ad5706r_id[] = { + { "ad5706r" }, + { } +}; +MODULE_DEVICE_TABLE(spi, ad5706r_id); + +static struct spi_driver ad5706r_driver = { + .driver = { + .name = "ad5706r", + .of_match_table = ad5706r_of_match, + }, + .probe = ad5706r_probe, + .id_table = ad5706r_id, +}; +module_spi_driver(ad5706r_driver); + +MODULE_AUTHOR("Alexis Czezar Torreno <alexisczezar.torreno@analog.com>"); +MODULE_DESCRIPTION("AD5706R 16-bit Current Output DAC driver"); +MODULE_LICENSE("GPL"); -- 2.34.1
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