The AD7292 is a 10-bit monitor and control system with ADC, DACs, temperature sensor, and GPIOs. Configure AD7292 devices in direct access mode, enabling single-ended ADC readings. Datasheet: Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx> --- Changelog V2 -> V3: - fix up a typo in channel macros MAINTAINERS | 1 + drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 362 insertions(+) create mode 100644 drivers/iio/adc/ad7292.c diff --git a/MAINTAINERS b/MAINTAINERS index 5d00e871c4c6..5941cfc0d6f7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -818,6 +818,7 @@ M: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx> L: linux-iio@xxxxxxxxxxxxxxx W: http://ez.analog.com/community/linux-device-drivers S: Supported +F: drivers/iio/adc/ad7292.c F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml ANALOG DEVICES INC AD7606 DRIVER diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 632b331429c6..02587c990cb5 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -59,6 +59,16 @@ config AD7291 To compile this driver as a module, choose M here: the module will be called ad7291. +config AD7292 + tristate "Analog Devices AD7292 ADC driver" + depends on SPI + help + Say yes here to build support for Analog Devices AD7292 + 8 Channel ADC with temperature sensor. + + To compile this driver as a module, choose M here: the + module will be called ad7292. + config AD7298 tristate "Analog Devices AD7298 ADC driver" depends on SPI diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 4779ab3ff8fb..1818f2f66566 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o obj-$(CONFIG_AD7173) += ad7173.o obj-$(CONFIG_AD7266) += ad7266.o obj-$(CONFIG_AD7291) += ad7291.o +obj-$(CONFIG_AD7292) += ad7292.o obj-$(CONFIG_AD7298) += ad7298.o obj-$(CONFIG_AD738X) += ad738x.o obj-$(CONFIG_AD7768) += ad7768-1.o diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c new file mode 100644 index 000000000000..e2badf6ac10d --- /dev/null +++ b/drivers/iio/adc/ad7292.c @@ -0,0 +1,350 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Analog Devices AD7292 SPI ADC driver + * + * Copyright 2019 Analog Devices Inc. + */ + +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> + +#define ADI_VENDOR_ID 0x0018 + +/* AD7292 registers definition */ +#define AD7292_REG_VENDOR_ID 0x00 +#define AD7292_REG_CONF_BANK 0x05 +#define AD7292_REG_CONV_COMM 0x0E +#define AD7292_REG_ADC_CH(x) (0x10 + (x)) + +/* AD7292 configuration bank subregisters definition */ +#define AD7292_BANK_REG_VIN_RNG0 0x10 +#define AD7292_BANK_REG_VIN_RNG1 0x11 +#define AD7292_BANK_REG_SAMP_MODE 0x12 + +#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F)) + +/* AD7292_REG_ADC_CONVERSION */ +#define AD7292_ADC_DATA_MASK GENMASK(15, 6) +#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x) + +/* AD7292_CHANNEL_SAMPLING_MODE */ +#define AD7292_CH_SAMP_MODE(reg, ch) ((reg >> 8) & BIT(ch)) + +/* AD7292_CHANNEL_VIN_RANGE */ +#define AD7292_CH_VIN_RANGE(reg, ch) (reg & BIT(ch)) + +#define AD7292_VOLTAGE_CHAN(_chan) \ +{ \ + .type = IIO_VOLTAGE, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .indexed = 1, \ + .channel = _chan, \ +} + +static const struct iio_chan_spec ad7292_channels[] = { + AD7292_VOLTAGE_CHAN(0), + AD7292_VOLTAGE_CHAN(1), + AD7292_VOLTAGE_CHAN(2), + AD7292_VOLTAGE_CHAN(3), + AD7292_VOLTAGE_CHAN(4), + AD7292_VOLTAGE_CHAN(5), + AD7292_VOLTAGE_CHAN(6), + AD7292_VOLTAGE_CHAN(7) +}; + +static const struct iio_chan_spec ad7292_channels_diff[] = { + { + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .indexed = 1, + .differential = 1, + .channel = 0, + .channel2 = 1, + }, + AD7292_VOLTAGE_CHAN(2), + AD7292_VOLTAGE_CHAN(3), + AD7292_VOLTAGE_CHAN(4), + AD7292_VOLTAGE_CHAN(5), + AD7292_VOLTAGE_CHAN(6), + AD7292_VOLTAGE_CHAN(7) +}; + +struct ad7292_state { + struct spi_device *spi; + struct regulator *reg; + unsigned short vref_mv; + + __be16 d16 ____cacheline_aligned; + u8 d8[2]; +}; + +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr) +{ + int ret; + + st->d8[0] = AD7292_RD_FLAG_MSK(addr); + + ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2); + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16); +} + +static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr, + unsigned int sub_addr, unsigned int len) +{ + unsigned int shift = 16 - (8 * len); + int ret; + + st->d8[0] = AD7292_RD_FLAG_MSK(addr); + st->d8[1] = sub_addr; + + ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len); + if (ret < 0) + return ret; + + return (be16_to_cpu(st->d16) >> shift); +} + +static int ad7292_single_conversion(struct ad7292_state *st, + unsigned int chan_addr) +{ + int ret; + + struct spi_transfer t[] = { + { + .tx_buf = &st->d8, + .len = 4, + .delay_usecs = 6, + }, { + .rx_buf = &st->d16, + .len = 2, + }, + }; + + st->d8[0] = chan_addr; + st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM); + + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); + + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16); +} + +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel) +{ + int samp_mode, range0, range1, factor = 1; + + /* + * Every AD7292 ADC channel may have its input range adjusted according + * to the settings at the ADC sampling mode and VIN range subregisters. + * For a given channel, the minimum input range is equal to Vref, and it + * may be increased by a multiplier factor of 2 or 4 according to the + * following rule: + * If channel is being sampled with respect to AGND: + * factor = 4 if VIN range0 and VIN range1 equal 0 + * factor = 2 if only one of VIN ranges equal 1 + * factor = 1 if both VIN range0 and VIN range1 equal 1 + * If channel is being sampled with respect to AVDD: + * factor = 4 if VIN range0 and VIN range1 equal 0 + * Behavior is undefined if any of VIN range doesn't equal 0 + */ + + samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_SAMP_MODE, 2); + + if (samp_mode < 0) + return samp_mode; + + range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_VIN_RNG0, 2); + + if (range0 < 0) + return range0; + + range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_VIN_RNG1, 2); + + if (range1 < 0) + return range1; + + if (AD7292_CH_SAMP_MODE(samp_mode, channel)) { + /* Sampling with respect to AGND */ + if (!AD7292_CH_VIN_RANGE(range0, channel)) + factor *= 2; + + if (!AD7292_CH_VIN_RANGE(range1, channel)) + factor *= 2; + + } else { + /* Sampling with respect to AVDD */ + if (AD7292_CH_VIN_RANGE(range0, channel) || + AD7292_CH_VIN_RANGE(range1, channel)) + return -EPERM; + + factor = 4; + } + + return factor; +} + +static int ad7292_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long info) +{ + struct ad7292_state *st = iio_priv(indio_dev); + unsigned int ch_addr; + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + ch_addr = AD7292_REG_ADC_CH(chan->channel); + ret = ad7292_single_conversion(st, ch_addr); + if (ret < 0) + return ret; + + *val = AD7292_ADC_DATA(ret); + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* + * To convert a raw value to standard units, the IIO defines + * this formula: Scaled value = (raw + offset) * scale. + * For the scale to be a correct multiplier for (raw + offset), + * it must be calculated as the input range divided by the + * number of possible distinct input values. Given the ADC data + * is 10 bit long, it may assume 2^10 distinct values. + * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2 + * return type indicates to the IIO API to divide *val by 2 to + * the power of *val2 when returning from read_raw. + */ + + ret = ad7292_vin_range_multiplier(st, chan->channel); + if (ret < 0) + return ret; + + *val = st->vref_mv * ret; + *val2 = 10; + return IIO_VAL_FRACTIONAL_LOG2; + default: + break; + } + return -EINVAL; +} + +static const struct iio_info ad7292_info = { + .read_raw = ad7292_read_raw, +}; + +static void ad7292_regulator_disable(void *data) +{ + struct ad7292_state *st = data; + + regulator_disable(st->reg); +} + +static int ad7292_probe(struct spi_device *spi) +{ + struct ad7292_state *st; + struct iio_dev *indio_dev; + struct device_node *child; + bool diff_channels = 0; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID); + if (ret != ADI_VENDOR_ID) { + dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret); + return -EINVAL; + } + + spi_set_drvdata(spi, indio_dev); + + st->reg = devm_regulator_get_optional(&spi->dev, "vref"); + if (!IS_ERR(st->reg)) { + ret = regulator_enable(st->reg); + if (ret) { + dev_err(&spi->dev, + "Failed to enable external vref supply\n"); + return ret; + } + + ret = devm_add_action_or_reset(&spi->dev, + ad7292_regulator_disable, st); + if (ret) { + regulator_disable(st->reg); + return ret; + } + + ret = regulator_get_voltage(st->reg); + if (ret < 0) + return ret; + + st->vref_mv = ret / 1000; + } else { + /* Use the internal voltage reference. */ + st->vref_mv = 1250; + } + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &ad7292_info; + + for_each_available_child_of_node(spi->dev.of_node, child) { + diff_channels = of_property_read_bool(child, "diff-channels"); + if (diff_channels) + break; + } + + if (diff_channels) { + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff); + indio_dev->channels = ad7292_channels_diff; + } else { + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels); + indio_dev->channels = ad7292_channels; + } + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct spi_device_id ad7292_id_table[] = { + { "ad7292", 0 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7292_id_table); + +static const struct of_device_id ad7292_of_match[] = { + { .compatible = "adi,ad7292" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ad7292_of_match); + +static struct spi_driver ad7292_driver = { + .driver = { + .name = "ad7292", + .of_match_table = ad7292_of_match, + }, + .probe = ad7292_probe, + .id_table = ad7292_id_table, +}; +module_spi_driver(ad7292_driver); + +MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>"); +MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver"); +MODULE_LICENSE("GPL v2"); -- 2.23.0
