From: David Lechner <dlechner@xxxxxxxxxxxx> This adds a new driver for the AD7380 family ADCs. The driver currently implements basic support for the AD7380, AD7381, 2-channel differential ADCs. Support for additional single-ended, pseudo-differential and 4-channel chips that use the same register map as well as additional features of the chip will be added in future patches. Co-developed-by: Stefan Popa <stefan.popa@xxxxxxxxxx> Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx> Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> [Julien Stephan: add datasheet links of supported parts] [Julien Stephan: fix rx/tx buffer for regmap access] [Julien Stephan: fix scale issue] [Julien Stephan: use the new iio_device_claim_direct_scoped instead of iio_device_claim_direct_mode] Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx> --- MAINTAINERS | 1 + drivers/iio/adc/Kconfig | 16 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ad7380.c | 438 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 456 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 4f162600e982..315b3060946f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -435,6 +435,7 @@ S: Supported W: https://wiki.analog.com/resources/tools-software/linux-drivers/iio-adc/ad738x W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml +F: drivers/iio/adc/ad7380.c AD7877 TOUCHSCREEN DRIVER M: Michael Hennerich <michael.hennerich@xxxxxxxxxx> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 8db68b80b391..631386b037ae 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -155,6 +155,22 @@ config AD7298 To compile this driver as a module, choose M here: the module will be called ad7298. +config AD7380 + tristate "Analog Devices AD7380 ADC driver" + depends on SPI_MASTER + select IIO_BUFFER + select IIO_TRIGGER + select IIO_TRIGGERED_BUFFER + help + AD7380 is a family of simultaneous sampling ADCs that share the same + SPI register map and have similar pinouts. + + Say yes here to build support for Analog Devices AD7380 ADC and + similar chips. + + To compile this driver as a module, choose M here: the module will be + called ad7380. + config AD7476 tristate "Analog Devices AD7476 1-channel ADCs driver and other similar devices from AD and TI" depends on SPI diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index edb32ce2af02..bd3cbbb178fa 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_AD7291) += ad7291.o obj-$(CONFIG_AD7292) += ad7292.o obj-$(CONFIG_AD7298) += ad7298.o obj-$(CONFIG_AD7923) += ad7923.o +obj-$(CONFIG_AD7380) += ad7380.o obj-$(CONFIG_AD7476) += ad7476.o obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c new file mode 100644 index 000000000000..dac7e11755ff --- /dev/null +++ b/drivers/iio/adc/ad7380.c @@ -0,0 +1,438 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Analog Devices AD738x Simultaneous Sampling SAR ADCs + * + * Copyright 2017 Analog Devices Inc. + * Copyright 2024 BayLibre, SAS + * + * Datasheets of supported parts: + * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf + */ + +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/cleanup.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +/* 2.5V internal reference voltage */ +#define AD7380_INTERNAL_REF_MV 2500 + +/* reading and writing registers is more reliable at lower than max speed */ +#define AD7380_REG_WR_SPEED_HZ 10000000 + +#define AD7380_REG_WR BIT(15) +#define AD7380_REG_REGADDR GENMASK(14, 12) +#define AD7380_REG_DATA GENMASK(11, 0) + +#define AD7380_REG_ADDR_NOP 0x0 +#define AD7380_REG_ADDR_CONFIG1 0x1 +#define AD7380_REG_ADDR_CONFIG2 0x2 +#define AD7380_REG_ADDR_ALERT 0x3 +#define AD7380_REG_ADDR_ALERT_LOW_TH 0x4 +#define AD7380_REG_ADDR_ALERT_HIGH_TH 0x5 + +#define AD7380_CONFIG1_OS_MODE BIT(9) +#define AD7380_CONFIG1_OSR GENMASK(8, 6) +#define AD7380_CONFIG1_CRC_W BIT(5) +#define AD7380_CONFIG1_CRC_R BIT(4) +#define AD7380_CONFIG1_ALERTEN BIT(3) +#define AD7380_CONFIG1_RES BIT(2) +#define AD7380_CONFIG1_REFSEL BIT(1) +#define AD7380_CONFIG1_PMODE BIT(0) + +#define AD7380_CONFIG2_SDO2 GENMASK(9, 8) +#define AD7380_CONFIG2_SDO BIT(8) +#define AD7380_CONFIG2_RESET GENMASK(7, 0) + +#define AD7380_CONFIG2_RESET_SOFT 0x3C +#define AD7380_CONFIG2_RESET_HARD 0xFF + +#define AD7380_ALERT_LOW_TH GENMASK(11, 0) +#define AD7380_ALERT_HIGH_TH GENMASK(11, 0) + +struct ad7380_chip_info { + const char *name; + const struct iio_chan_spec *channels; + unsigned int num_channels; +}; + +#define AD7380_CHANNEL(index, bits) { \ + .type = IIO_VOLTAGE, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .indexed = 1, \ + .differential = 1, \ + .channel = 2 * (index), \ + .channel2 = 2 * (index) + 1, \ + .scan_index = (index), \ + .scan_type = { \ + .sign = 's', \ + .realbits = (bits), \ + .storagebits = 16, \ + .endianness = IIO_CPU, \ + }, \ +} + +#define DEFINE_AD7380_2_CHANNEL(name, bits) \ +static const struct iio_chan_spec name[] = { \ + AD7380_CHANNEL(0, bits), \ + AD7380_CHANNEL(1, bits), \ + IIO_CHAN_SOFT_TIMESTAMP(2), \ +} + +DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16); +DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14); + +/* Since this is simultaneous sampling, we don't allow individual channels. */ +static const unsigned long ad7380_2_channel_scan_masks[] = { + GENMASK(1, 0), + 0 +}; + +static const struct ad7380_chip_info ad7380_chip_info = { + .name = "ad7380", + .channels = ad7380_channels, + .num_channels = ARRAY_SIZE(ad7380_channels), +}; + +static const struct ad7380_chip_info ad7381_chip_info = { + .name = "ad7381", + .channels = ad7381_channels, + .num_channels = ARRAY_SIZE(ad7381_channels), +}; + +struct ad7380_state { + const struct ad7380_chip_info *chip_info; + struct spi_device *spi; + struct regmap *regmap; + unsigned int vref_mv; + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + * Make the buffer large enough for 2 16-bit samples and one 64-bit + * aligned 64 bit timestamp. + */ + struct { + u16 raw[2]; + + s64 ts __aligned(8); + } scan_data __aligned(IIO_DMA_MINALIGN); + u16 tx; + u16 rx; +}; + +static int ad7380_regmap_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + struct ad7380_state *st = context; + struct spi_transfer xfer = { + .speed_hz = AD7380_REG_WR_SPEED_HZ, + .bits_per_word = 16, + .len = 2, + .tx_buf = &st->tx, + }; + + st->tx = FIELD_PREP(AD7380_REG_WR, 1) | + FIELD_PREP(AD7380_REG_REGADDR, reg) | + FIELD_PREP(AD7380_REG_DATA, val); + + return spi_sync_transfer(st->spi, &xfer, 1); +} + +static int ad7380_regmap_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + struct ad7380_state *st = context; + struct spi_transfer xfers[] = { + { + .speed_hz = AD7380_REG_WR_SPEED_HZ, + .bits_per_word = 16, + .len = 2, + .tx_buf = &st->tx, + .cs_change = 1, + .cs_change_delay = { + .value = 10, /* t[CSH] */ + .unit = SPI_DELAY_UNIT_NSECS, + }, + }, { + .speed_hz = AD7380_REG_WR_SPEED_HZ, + .bits_per_word = 16, + .len = 2, + .rx_buf = &st->rx, + }, + }; + int ret; + + st->tx = FIELD_PREP(AD7380_REG_WR, 0) | + FIELD_PREP(AD7380_REG_REGADDR, reg) | + FIELD_PREP(AD7380_REG_DATA, 0); + + ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); + if (ret < 0) + return ret; + + *val = FIELD_GET(AD7380_REG_DATA, st->rx); + + return 0; +} + +static const struct regmap_config ad7380_regmap_config = { + .reg_bits = 3, + .val_bits = 12, + .reg_read = ad7380_regmap_reg_read, + .reg_write = ad7380_regmap_reg_write, + .max_register = AD7380_REG_ADDR_ALERT_HIGH_TH, + .can_sleep = true, +}; + +static int ad7380_debugfs_reg_access(struct iio_dev *indio_dev, u32 reg, + u32 writeval, u32 *readval) +{ + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + struct ad7380_state *st = iio_priv(indio_dev); + + if (readval) + return regmap_read(st->regmap, reg, readval); + else + return regmap_write(st->regmap, reg, writeval); + } + unreachable(); +} + +static irqreturn_t ad7380_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad7380_state *st = iio_priv(indio_dev); + struct spi_transfer xfer = { + .bits_per_word = st->chip_info->channels[0].scan_type.realbits, + .len = 4, + .rx_buf = st->scan_data.raw, + }; + int ret; + + ret = spi_sync_transfer(st->spi, &xfer, 1); + if (ret) + goto out; + + iio_push_to_buffers_with_timestamp(indio_dev, &st->scan_data, + pf->timestamp); + +out: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int ad7380_read_direct(struct ad7380_state *st, + struct iio_chan_spec const *chan, int *val) +{ + struct spi_transfer xfers[] = { + /* toggle CS (no data xfer) to trigger a conversion */ + { + .speed_hz = AD7380_REG_WR_SPEED_HZ, + .bits_per_word = chan->scan_type.realbits, + .delay = { + .value = 190, /* t[CONVERT] */ + .unit = SPI_DELAY_UNIT_NSECS, + }, + .cs_change = 1, + .cs_change_delay = { + .value = 10, /* t[CSH] */ + .unit = SPI_DELAY_UNIT_NSECS, + }, + }, + /* then read both channels */ + { + .speed_hz = AD7380_REG_WR_SPEED_HZ, + .bits_per_word = chan->scan_type.realbits, + .rx_buf = st->scan_data.raw, + .len = 4, + }, + }; + int ret; + + ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); + if (ret < 0) + return ret; + + *val = sign_extend32(st->scan_data.raw[chan->scan_index], + chan->scan_type.realbits - 1); + + return IIO_VAL_INT; +} + +static int ad7380_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long info) +{ + struct ad7380_state *st = iio_priv(indio_dev); + + switch (info) { + case IIO_CHAN_INFO_RAW: + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + return ad7380_read_direct(st, chan, val); + } + unreachable(); + case IIO_CHAN_INFO_SCALE: + /* + * According to the datasheet, the LSB size for fully differential ADC is + * (2 × VREF) / 2^N, where N is the ADC resolution (i.e realbits) + */ + *val = st->vref_mv; + *val2 = chan->scan_type.realbits - 1; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static const struct iio_info ad7380_info = { + .read_raw = &ad7380_read_raw, + .debugfs_reg_access = &ad7380_debugfs_reg_access, +}; + +static int ad7380_init(struct ad7380_state *st, struct regulator *vref) +{ + int ret; + + /* perform hard reset */ + ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2, + AD7380_CONFIG2_RESET, + FIELD_PREP(AD7380_CONFIG2_RESET, + AD7380_CONFIG2_RESET_HARD)); + if (ret < 0) + return ret; + + /* select internal or external reference voltage */ + ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG1, + AD7380_CONFIG1_REFSEL, + FIELD_PREP(AD7380_CONFIG1_REFSEL, + vref ? 1 : 0)); + if (ret < 0) + return ret; + + /* SPI 1-wire mode */ + return regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2, + AD7380_CONFIG2_SDO, + FIELD_PREP(AD7380_CONFIG2_SDO, 1)); +} + +static void ad7380_regulator_disable(void *p) +{ + regulator_disable(p); +} + +static int ad7380_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct ad7380_state *st; + struct regulator *vref; + 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; + st->chip_info = spi_get_device_match_data(spi); + if (!st->chip_info) + return dev_err_probe(&spi->dev, -EINVAL, "missing match data\n"); + + vref = devm_regulator_get_optional(&spi->dev, "refio"); + if (IS_ERR(vref)) { + if (PTR_ERR(vref) != -ENODEV) + return dev_err_probe(&spi->dev, PTR_ERR(vref), + "Failed to get refio regulator\n"); + + vref = NULL; + } + + /* + * If there is no REFIO supply, then it means that we are using + * the internal 2.5V reference, otherwise REFIO is reference voltage. + */ + if (vref) { + ret = regulator_enable(vref); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&spi->dev, + ad7380_regulator_disable, vref); + if (ret) + return ret; + + ret = regulator_get_voltage(vref); + if (ret < 0) + return ret; + + st->vref_mv = ret / 1000; + } else { + st->vref_mv = AD7380_INTERNAL_REF_MV; + } + + st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config); + if (IS_ERR(st->regmap)) + return dev_err_probe(&spi->dev, PTR_ERR(st->regmap), + "failed to allocate register map\n"); + + indio_dev->channels = st->chip_info->channels; + indio_dev->num_channels = st->chip_info->num_channels; + indio_dev->name = st->chip_info->name; + indio_dev->info = &ad7380_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->available_scan_masks = ad7380_2_channel_scan_masks; + + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, + iio_pollfunc_store_time, + ad7380_trigger_handler, NULL); + if (ret) + return ret; + + ret = ad7380_init(st, vref); + if (ret) + return ret; + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct of_device_id ad7380_of_match_table[] = { + { .compatible = "adi,ad7380", .data = &ad7380_chip_info }, + { .compatible = "adi,ad7381", .data = &ad7381_chip_info }, + { } +}; + +static const struct spi_device_id ad7380_id_table[] = { + { "ad7380", (kernel_ulong_t)&ad7380_chip_info }, + { "ad7381", (kernel_ulong_t)&ad7381_chip_info }, + { } +}; +MODULE_DEVICE_TABLE(spi, ad7380_id_table); + +static struct spi_driver ad7380_driver = { + .driver = { + .name = "ad7380", + .of_match_table = ad7380_of_match_table, + }, + .probe = ad7380_probe, + .id_table = ad7380_id_table, +}; +module_spi_driver(ad7380_driver); + +MODULE_AUTHOR("Stefan Popa <stefan.popa@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Analog Devices AD738x ADC driver"); +MODULE_LICENSE("GPL"); -- 2.44.0
