From f52690c50893ef1504990199c8a2dfbb869f38c6 Mon Sep 17 00:00:00 2001 From: Janani Sunil Date: Mon, 19 Jan 2026 12:24:24 +0100 Subject: [PATCH] iio: dac: Add MAX22007 DAC driver support Add support for the MAX22007 4 channel DAC that drives a voltage or current output on each channel. Signed-off-by: Janani Sunil Signed-off-by: Jonathan Cameron --- MAINTAINERS | 1 + drivers/iio/dac/Kconfig | 13 + drivers/iio/dac/Makefile | 1 + drivers/iio/dac/max22007.c | 491 +++++++++++++++++++++++++++++++++++++ 4 files changed, 506 insertions(+) create mode 100644 drivers/iio/dac/max22007.c diff --git a/MAINTAINERS b/MAINTAINERS index 19a9140af9b7..70163f939602 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1616,6 +1616,7 @@ L: linux-iio@vger.kernel.org S: Supported W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/dac/adi,max22007.yaml +F: drivers/iio/dac/max22007.c ANALOG DEVICES INC ADA4250 DRIVER M: Antoniu Miclaus diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig index e47d73300b07..db9f5c711b3d 100644 --- a/drivers/iio/dac/Kconfig +++ b/drivers/iio/dac/Kconfig @@ -482,6 +482,19 @@ config MAX517 This driver can also be built as a module. If so, the module will be called max517. +config MAX22007 + tristate "Analog Devices MAX22007 DAC Driver" + depends on SPI + select REGMAP_SPI + select CRC8 + help + Say Y here if you want to build a driver for Analog Devices MAX22007. + + MAX22007 is a quad-channel, 12-bit, voltage-output digital to + analog converter (DAC) with SPI interface. + + If compiled as a module, it will be called max22007. + config MAX5522 tristate "Maxim MAX5522 DAC driver" depends on SPI_MASTER diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile index 9443e3c71c79..2a80bbf4e80a 100644 --- a/drivers/iio/dac/Makefile +++ b/drivers/iio/dac/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_LTC2664) += ltc2664.o obj-$(CONFIG_LTC2688) += ltc2688.o obj-$(CONFIG_M62332) += m62332.o obj-$(CONFIG_MAX517) += max517.o +obj-$(CONFIG_MAX22007) += max22007.o obj-$(CONFIG_MAX5522) += max5522.o obj-$(CONFIG_MAX5821) += max5821.o obj-$(CONFIG_MCP4725) += mcp4725.o diff --git a/drivers/iio/dac/max22007.c b/drivers/iio/dac/max22007.c new file mode 100644 index 000000000000..182ac7155a89 --- /dev/null +++ b/drivers/iio/dac/max22007.c @@ -0,0 +1,491 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * max22007.c - MAX22007 DAC driver + * + * Driver for Analog Devices MAX22007 Digital to Analog Converter. + * + * Copyright (c) 2026 Analog Devices Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +struct device; + +#define MAX22007_NUM_CHANNELS 4 +#define MAX22007_REV_ID_REG 0x00 +#define MAX22007_STAT_INTR_REG 0x01 +#define MAX22007_INTERRUPT_EN_REG 0x02 +#define MAX22007_CONFIG_REG 0x03 +#define MAX22007_CONTROL_REG 0x04 +#define MAX22007_CHANNEL_MODE_REG 0x05 +#define MAX22007_SOFT_RESET_REG 0x06 +#define MAX22007_DAC_CHANNEL_REG(ch) (0x07 + (ch)) +#define MAX22007_GPIO_CTRL_REG 0x0B +#define MAX22007_GPIO_DATA_REG 0x0C +#define MAX22007_GPI_EDGE_INT_CTRL_REG 0x0D +#define MAX22007_GPI_INT_STATUS_REG 0x0E + +/* Channel mask definitions */ +#define MAX22007_CH_MODE_CH_MASK(ch) BIT(12 + (ch)) +#define MAX22007_CH_PWRON_CH_MASK(ch) BIT(8 + (ch)) +#define MAX22007_DAC_LATCH_MODE_MASK(ch) BIT(12 + (ch)) +#define MAX22007_LDAC_UPDATE_MASK(ch) BIT(12 + (ch)) +#define MAX22007_SW_RST_MASK BIT(8) +#define MAX22007_SW_CLR_MASK BIT(12) +#define MAX22007_SOFT_RESET_BITS_MASK (MAX22007_SW_RST_MASK | \ + MAX22007_SW_CLR_MASK) +#define MAX22007_DAC_DATA_MASK GENMASK(15, 4) +#define MAX22007_DAC_MAX_RAW GENMASK(11, 0) +#define MAX22007_CRC8_POLYNOMIAL 0x8C +#define MAX22007_CRC_EN_MASK BIT(0) +#define MAX22007_RW_MASK BIT(0) +#define MAX22007_CRC_OVERHEAD 1 +#define MAX22007_NUM_SUPPLIES 3 +#define MAX22007_REF_MV 2500 + +/* Field value preparation macros with masking */ +#define MAX22007_CH_PWR_VAL(ch, val) (((val) & 0x1) << (8 + (ch))) +#define MAX22007_CH_MODE_VAL(ch, val) (((val) & 0x1) << (12 + (ch))) +#define MAX22007_DAC_LATCH_MODE_VAL(ch, val) (((val) & 0x1) << (12 + (ch))) + +static u8 max22007_crc8_table[CRC8_TABLE_SIZE]; + +static const char * const max22007_supply_names[MAX22007_NUM_SUPPLIES] = { + "vdd", + "hvdd", + "hvss", +}; + +struct max22007_state { + struct spi_device *spi; + struct regmap *regmap; + struct iio_chan_spec *iio_chans; + u8 tx_buf[4] __aligned(IIO_DMA_MINALIGN); + u8 rx_buf[4]; +}; + +static int max22007_spi_read(void *context, const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + struct max22007_state *st = context; + u8 calculated_crc, received_crc; + u8 rx_buf[4]; + u8 reg_byte; + int ret; + + if (reg_size != 1) + return -EINVAL; + + if (val_size == 0 || val_size > 3) + return -EINVAL; + + memcpy(®_byte, reg, 1); + + ret = spi_write_then_read(st->spi, ®_byte, 1, rx_buf, + val_size + MAX22007_CRC_OVERHEAD); + if (ret) { + dev_err(&st->spi->dev, "SPI transfer failed: %d\n", ret); + return ret; + } + + calculated_crc = crc8(max22007_crc8_table, ®_byte, 1, 0x00); + calculated_crc = crc8(max22007_crc8_table, rx_buf, 2, calculated_crc); + received_crc = rx_buf[val_size]; + + if (calculated_crc != received_crc) { + dev_err(&st->spi->dev, "CRC mismatch on read register %02x\n", reg_byte); + return -EIO; + } + + memcpy(val, rx_buf, val_size); + + return 0; +} + +static int max22007_spi_write(void *context, const void *data, size_t count) +{ + struct max22007_state *st = context; + struct spi_transfer xfer = { + .tx_buf = st->tx_buf, + .rx_buf = st->rx_buf, + }; + + if (count + MAX22007_CRC_OVERHEAD > sizeof(st->tx_buf)) + return -EINVAL; + + memset(st->tx_buf, 0, sizeof(st->tx_buf)); + + xfer.len = count + MAX22007_CRC_OVERHEAD; + + memcpy(st->tx_buf, data, count); + st->tx_buf[count] = crc8(max22007_crc8_table, st->tx_buf, + sizeof(st->tx_buf) - 1, 0x00); + + return spi_sync_transfer(st->spi, &xfer, 1); +} + +static bool max22007_reg_readable(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX22007_REV_ID_REG: + case MAX22007_STAT_INTR_REG: + case MAX22007_CONFIG_REG: + case MAX22007_CONTROL_REG: + case MAX22007_CHANNEL_MODE_REG: + case MAX22007_SOFT_RESET_REG: + case MAX22007_GPIO_CTRL_REG: + case MAX22007_GPIO_DATA_REG: + case MAX22007_GPI_EDGE_INT_CTRL_REG: + case MAX22007_GPI_INT_STATUS_REG: + return true; + case MAX22007_DAC_CHANNEL_REG(0) ... MAX22007_DAC_CHANNEL_REG(MAX22007_NUM_CHANNELS - 1): + return true; + default: + return false; + } +} + +static bool max22007_reg_writable(struct device *dev, unsigned int reg) +{ + switch (reg) { + case MAX22007_CONFIG_REG: + case MAX22007_CONTROL_REG: + case MAX22007_CHANNEL_MODE_REG: + case MAX22007_SOFT_RESET_REG: + case MAX22007_GPIO_CTRL_REG: + case MAX22007_GPIO_DATA_REG: + case MAX22007_GPI_EDGE_INT_CTRL_REG: + return true; + case MAX22007_DAC_CHANNEL_REG(0) ... MAX22007_DAC_CHANNEL_REG(MAX22007_NUM_CHANNELS - 1): + return true; + default: + return false; + } +} + +static const struct regmap_bus max22007_regmap_bus = { + .read = max22007_spi_read, + .write = max22007_spi_write, + .read_flag_mask = MAX22007_RW_MASK, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, +}; + +static const struct regmap_config max22007_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .reg_shift = -1, + .readable_reg = max22007_reg_readable, + .writeable_reg = max22007_reg_writable, + .max_register = 0x0E, +}; + +static int max22007_write_channel_data(struct max22007_state *st, + unsigned int channel, int data) +{ + unsigned int reg_val; + + if (data < 0 || data > MAX22007_DAC_MAX_RAW) + return -EINVAL; + + reg_val = FIELD_PREP(MAX22007_DAC_DATA_MASK, data); + + return regmap_write(st->regmap, MAX22007_DAC_CHANNEL_REG(channel), reg_val); +} + +static int max22007_read_channel_data(struct max22007_state *st, + unsigned int channel, int *data) +{ + unsigned int reg_val; + int ret; + + ret = regmap_read(st->regmap, MAX22007_DAC_CHANNEL_REG(channel), ®_val); + if (ret) + return ret; + + *data = FIELD_GET(MAX22007_DAC_DATA_MASK, reg_val); + + return 0; +} + +static int max22007_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct max22007_state *st = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = max22007_read_channel_data(st, chan->channel, val); + if (ret) + return ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + if (chan->type == IIO_VOLTAGE) + *val = 5 * MAX22007_REF_MV; /* 5 * Vref in mV */ + else + *val = 25; /* Vref / (2 * Rsense) = MAX22007_REF_MV / 100 */ + *val2 = 12; /* 12-bit DAC resolution */ + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static int max22007_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct max22007_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return max22007_write_channel_data(st, chan->channel, val); + default: + return -EINVAL; + } +} + +static const struct iio_info max22007_info = { + .read_raw = max22007_read_raw, + .write_raw = max22007_write_raw, +}; + +static ssize_t max22007_read_dac_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct max22007_state *st = iio_priv(indio_dev); + unsigned int reg_val; + bool powerdown; + int ret; + + ret = regmap_read(st->regmap, MAX22007_CHANNEL_MODE_REG, ®_val); + if (ret) + return ret; + + powerdown = !(reg_val & MAX22007_CH_PWRON_CH_MASK(chan->channel)); + + return sysfs_emit(buf, "%d\n", powerdown); +} + +static ssize_t max22007_write_dac_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct max22007_state *st = iio_priv(indio_dev); + bool powerdown; + int ret; + + ret = kstrtobool(buf, &powerdown); + if (ret) + return ret; + + ret = regmap_update_bits(st->regmap, MAX22007_CHANNEL_MODE_REG, + MAX22007_CH_PWRON_CH_MASK(chan->channel), + MAX22007_CH_PWR_VAL(chan->channel, powerdown ? 0 : 1)); + if (ret) + return ret; + + return len; +} + +static const struct iio_chan_spec_ext_info max22007_ext_info[] = { + { + .name = "powerdown", + .read = max22007_read_dac_powerdown, + .write = max22007_write_dac_powerdown, + .shared = IIO_SEPARATE, + }, + { } +}; + +static int max22007_parse_channel_cfg(struct max22007_state *st, u8 *num_channels) +{ + struct device *dev = &st->spi->dev; + int ret, num_chan; + int i = 0; + u32 reg; + + num_chan = device_get_child_node_count(dev); + if (!num_chan) + return dev_err_probe(dev, -ENODEV, "no channels configured\n"); + + st->iio_chans = devm_kcalloc(dev, num_chan, sizeof(*st->iio_chans), GFP_KERNEL); + if (!st->iio_chans) + return -ENOMEM; + + device_for_each_child_node_scoped(dev, child) { + u32 ch_func; + enum iio_chan_type chan_type; + + ret = fwnode_property_read_u32(child, "reg", ®); + if (ret) + return dev_err_probe(dev, ret, + "failed to read reg property of %pfwP\n", child); + + if (reg >= MAX22007_NUM_CHANNELS) + return dev_err_probe(dev, -EINVAL, + "reg out of range in %pfwP\n", child); + + ret = fwnode_property_read_u32(child, "adi,ch-func", &ch_func); + if (ret) + return dev_err_probe(dev, ret, + "missing adi,ch-func property for %pfwP\n", child); + + switch (ch_func) { + case CH_FUNC_VOLTAGE_OUTPUT: + chan_type = IIO_VOLTAGE; + break; + case CH_FUNC_CURRENT_OUTPUT: + chan_type = IIO_CURRENT; + break; + default: + return dev_err_probe(dev, -EINVAL, + "invalid adi,ch-func %u for %pfwP\n", + ch_func, child); + } + + st->iio_chans[i++] = (struct iio_chan_spec) { + .output = 1, + .indexed = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .ext_info = max22007_ext_info, + .channel = reg, + .type = chan_type, + }; + + ret = regmap_update_bits(st->regmap, MAX22007_CHANNEL_MODE_REG, + MAX22007_CH_MODE_CH_MASK(reg), + MAX22007_CH_MODE_VAL(reg, ch_func - 1)); + if (ret) + return ret; + + /* Set DAC to transparent mode (immediate update) */ + ret = regmap_update_bits(st->regmap, MAX22007_CONFIG_REG, + MAX22007_DAC_LATCH_MODE_MASK(reg), + MAX22007_DAC_LATCH_MODE_VAL(reg, 1)); + if (ret) + return ret; + } + + *num_channels = num_chan; + + return 0; +} + +static int max22007_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct gpio_desc *reset_gpio; + struct max22007_state *st; + struct iio_dev *indio_dev; + u8 num_channels; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + crc8_populate_lsb(max22007_crc8_table, MAX22007_CRC8_POLYNOMIAL); + + st->regmap = devm_regmap_init(dev, &max22007_regmap_bus, st, + &max22007_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(dev, PTR_ERR(st->regmap), + "Failed to initialize regmap\n"); + + ret = devm_regulator_bulk_get_enable(dev, MAX22007_NUM_SUPPLIES, + max22007_supply_names); + if (ret) + return dev_err_probe(dev, ret, "Failed to get and enable regulators\n"); + + reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(reset_gpio)) + return dev_err_probe(dev, PTR_ERR(reset_gpio), + "Failed to get reset GPIO\n"); + + if (reset_gpio) { + gpiod_set_value_cansleep(reset_gpio, 1); + usleep_range(1000, 5000); + gpiod_set_value_cansleep(reset_gpio, 0); + usleep_range(1000, 5000); + } else { + ret = regmap_write(st->regmap, MAX22007_SOFT_RESET_REG, + MAX22007_SOFT_RESET_BITS_MASK); + if (ret) + return ret; + } + + ret = regmap_set_bits(st->regmap, MAX22007_CONFIG_REG, + MAX22007_CRC_EN_MASK); + if (ret) + return ret; + + ret = max22007_parse_channel_cfg(st, &num_channels); + if (ret) + return ret; + + indio_dev->info = &max22007_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->iio_chans; + indio_dev->num_channels = num_channels; + indio_dev->name = "max22007"; + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id max22007_id[] = { + { "max22007" }, + { } +}; +MODULE_DEVICE_TABLE(spi, max22007_id); + +static const struct of_device_id max22007_of_match[] = { + { .compatible = "adi,max22007" }, + { } +}; +MODULE_DEVICE_TABLE(of, max22007_of_match); + +static struct spi_driver max22007_driver = { + .driver = { + .name = "max22007", + .of_match_table = max22007_of_match, + }, + .probe = max22007_probe, + .id_table = max22007_id, +}; +module_spi_driver(max22007_driver); + +MODULE_AUTHOR("Janani Sunil "); +MODULE_DESCRIPTION("Analog Devices MAX22007 DAC"); +MODULE_LICENSE("GPL"); -- 2.47.3