[PATCH v5 6/7] iio: adc: Add support for AD4000

Marcelo Schmitt
2024-06-25T21:56:04Z

Add support for AD4000 series of low noise, low power, high speed,
successive approximation register (SAR) ADCs.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad4000.c | 711 +++++++++++++++++++++++++++++++++++++++
4 files changed, 725 insertions(+)
create mode 100644 drivers/iio/adc/ad4000.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9aa6531f7cf2..f4ffedada8ea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1205,6 +1205,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad4000.yaml
+F: drivers/iio/adc/ad4000.c

ANALOG DEVICES INC AD4130 DRIVER
M: Cosmin Tanislav <cosmin.tanislav@analog.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index b8184706c7d1..5bbe843916a3 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -21,6 +21,18 @@ config AD_SIGMA_DELTA
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER

+config AD4000
+ tristate "Analog Devices AD4000 ADC Driver"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for Analog Devices AD4000 high speed
+ SPI analog to digital converters (ADC).
+
+ To compile this driver as a module, choose M here: the module will be
+ called ad4000.
+
config AD4130
tristate "Analog Device AD4130 ADC Driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 51298c52b223..f4361df40cca 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -6,6 +6,7 @@
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
+obj-$(CONFIG_AD4000) += ad4000.o
obj-$(CONFIG_AD4130) += ad4130.o
obj-$(CONFIG_AD7091R) += ad7091r-base.o
obj-$(CONFIG_AD7091R5) += ad7091r5.o
diff --git a/drivers/iio/adc/ad4000.c b/drivers/iio/adc/ad4000.c
new file mode 100644
index 000000000000..0b6293db68dc
--- /dev/null
+++ b/drivers/iio/adc/ad4000.c
@@ -0,0 +1,711 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD4000 SPI ADC driver
+ *
+ * Copyright 2024 Analog Devices Inc.
+ */
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/byteorder/generic.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+#include <linux/iio/iio.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define AD4000_READ_COMMAND 0x54
+#define AD4000_WRITE_COMMAND 0x14
+
+#define AD4000_CONFIG_REG_DEFAULT 0xE1
+
+/* AD4000 Configuration Register programmable bits */
+#define AD4000_CFG_STATUS BIT(4) /* Status bits output */
+#define AD4000_CFG_SPAN_COMP BIT(3) /* Input span compression */
+#define AD4000_CFG_HIGHZ BIT(2) /* High impedance mode */
+#define AD4000_CFG_TURBO BIT(1) /* Turbo mode */
+
+#define AD4000_SCALE_OPTIONS 2
+
+#define AD4000_TQUIET1_NS 190
+#define AD4000_TQUIET2_NS 60
+#define AD4000_TCONV_NS 320
+
+#define __AD4000_DIFF_CHANNEL(_sign, _real_bits, _storage_bits, _reg_access) \
+{ \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .differential = 1, \
+ .channel = 0, \
+ .channel2 = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_separate_available = _reg_access ? BIT(IIO_CHAN_INFO_SCALE) : 0,\
+ .scan_type = { \
+ .sign = _sign, \
+ .realbits = _real_bits, \
+ .storagebits = _storage_bits, \
+ .shift = _storage_bits - _real_bits, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+#define AD4000_DIFF_CHANNEL(_sign, _real_bits, _reg_access) \
+ __AD4000_DIFF_CHANNEL((_sign), (_real_bits), \
+ ((_real_bits) > 16 ? 32 : 16), (_reg_access))
+
+#define __AD4000_PSEUDO_DIFF_CHANNEL(_sign, _real_bits, _storage_bits, _reg_access)\
+{ \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = 0, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+ .info_mask_separate_available = _reg_access ? BIT(IIO_CHAN_INFO_SCALE) : 0,\
+ .scan_type = { \
+ .sign = _sign, \
+ .realbits = _real_bits, \
+ .storagebits = _storage_bits, \
+ .shift = _storage_bits - _real_bits, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+#define AD4000_PSEUDO_DIFF_CHANNEL(_sign, _real_bits, _reg_access) \
+ __AD4000_PSEUDO_DIFF_CHANNEL((_sign), (_real_bits), \
+ ((_real_bits) > 16 ? 32 : 16), (_reg_access))
+
+enum ad4000_sdi {
+ /* datasheet calls this "4-wire mode" (controller CS goes to ADC SDI!) */
+ AD4000_SDI_MOSI,
+ /* datasheet calls this "3-wire mode" (not related to SPI_3WIRE!) */
+ AD4000_SDI_VIO,
+ AD4000_SDI_CS,
+};
+
+/* maps adi,sdi-pin property value to enum */
+static const char * const ad4000_sdi_pin[] = {
+ [AD4000_SDI_MOSI] = "",
+ [AD4000_SDI_VIO] = "high",
+ [AD4000_SDI_CS] = "cs",
+};
+
+struct ad4000_chip_info {
+ const char *dev_name;
+ struct iio_chan_spec chan_spec;
+ struct iio_chan_spec reg_access_chan_spec;
+ bool has_hardware_gain;
+};
+
+static const struct ad4000_chip_info ad4000_chip_info = {
+ .dev_name = "ad4000",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 1),
+};
+
+static const struct ad4000_chip_info ad4001_chip_info = {
+ .dev_name = "ad4001",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 16, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 16, 1),
+};
+
+static const struct ad4000_chip_info ad4002_chip_info = {
+ .dev_name = "ad4002",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4003_chip_info = {
+ .dev_name = "ad4003",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 18, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4004_chip_info = {
+ .dev_name = "ad4004",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 1),
+};
+
+static const struct ad4000_chip_info ad4005_chip_info = {
+ .dev_name = "ad4005",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 16, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 16, 1),
+};
+
+static const struct ad4000_chip_info ad4006_chip_info = {
+ .dev_name = "ad4006",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4007_chip_info = {
+ .dev_name = "ad4007",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 18, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4008_chip_info = {
+ .dev_name = "ad4008",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 16, 1),
+};
+
+static const struct ad4000_chip_info ad4010_chip_info = {
+ .dev_name = "ad4010",
+ .chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 0),
+ .reg_access_chan_spec = AD4000_PSEUDO_DIFF_CHANNEL('u', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4011_chip_info = {
+ .dev_name = "ad4011",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 18, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 18, 1),
+};
+
+static const struct ad4000_chip_info ad4020_chip_info = {
+ .dev_name = "ad4020",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 20, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 20, 1),
+};
+
+static const struct ad4000_chip_info ad4021_chip_info = {
+ .dev_name = "ad4021",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 20, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 20, 1),
+};
+
+static const struct ad4000_chip_info ad4022_chip_info = {
+ .dev_name = "ad4022",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 20, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 20, 1),
+};
+
+static const struct ad4000_chip_info adaq4001_chip_info = {
+ .dev_name = "adaq4001",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 16, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 16, 1),
+ .has_hardware_gain = true,
+};
+
+static const struct ad4000_chip_info adaq4003_chip_info = {
+ .dev_name = "adaq4003",
+ .chan_spec = AD4000_DIFF_CHANNEL('s', 18, 0),
+ .reg_access_chan_spec = AD4000_DIFF_CHANNEL('s', 18, 1),
+ .has_hardware_gain = true,
+};
+
+struct ad4000_state {
+ struct spi_device *spi;
+ struct gpio_desc *cnv_gpio;
+ struct spi_transfer xfers[2];
+ struct spi_message msg;
+ struct mutex lock; /* Protect read modify write cycle */
+ int vref_mv;
+ enum ad4000_sdi sdi_pin;
+ bool span_comp;
+ bool turbo_mode;
+ u16 gain_milli;
+ int scale_tbl[AD4000_SCALE_OPTIONS][2];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the transfer buffers
+ * to live in their own cache lines.
+ */
+ struct {
+ union {
+ __be16 sample_buf16;
+ __be32 sample_buf32;
+ } data;
+ s64 timestamp __aligned(8);
+ } scan __aligned(IIO_DMA_MINALIGN);
+ u8 tx_buf[2];
+ u8 rx_buf[2];
+};
+
+static void ad4000_fill_scale_tbl(struct ad4000_state *st,
+ struct iio_chan_spec const *chan)
+{
+ int val, tmp0, tmp1;
+ int scale_bits;
+ u64 tmp2;
+
+ /*
+ * ADCs that output two's complement code have one less bit to express
+ * voltage magnitude.
+ */
+ if (chan->scan_type.sign == 's')
+ scale_bits = chan->scan_type.realbits - 1;
+ else
+ scale_bits = chan->scan_type.realbits;
+
+ /*
+ * The gain is stored as a fraction of 1000 and, as we need to
+ * divide vref_mv by the gain, we invert the gain/1000 fraction.
+ * Also multiply by an extra MILLI to preserve precision.
+ * Thus, we have MILLI * MILLI equals MICRO as fraction numerator.
+ */
+ val = mult_frac(st->vref_mv, MICRO, st->gain_milli);
+ /* Would multiply by NANO here but we multiplied by extra MILLI */
+ tmp2 = shift_right((u64)val * MICRO, scale_bits);
+ tmp0 = div_s64_rem(tmp2, NANO, &tmp1);
+ /* Store scale for when span compression is disabled */
+ st->scale_tbl[0][0] = tmp0; /* Integer part */
+ st->scale_tbl[0][1] = abs(tmp1); /* Fractional part */
+ /* Store scale for when span compression is enabled */
+ st->scale_tbl[1][0] = tmp0;
+ /* The integer part is always zero so don't bother to divide it. */
+ if (chan->differential)
+ st->scale_tbl[1][1] = DIV_ROUND_CLOSEST(abs(tmp1) * 4, 5);
+ else
+ st->scale_tbl[1][1] = DIV_ROUND_CLOSEST(abs(tmp1) * 9, 10);
+}
+
+static int ad4000_write_reg(struct ad4000_state *st, uint8_t val)
+{
+ st->tx_buf[0] = AD4000_WRITE_COMMAND;
+ st->tx_buf[1] = val;
+ return spi_write(st->spi, st->tx_buf, ARRAY_SIZE(st->tx_buf));
+}
+
+static int ad4000_read_reg(struct ad4000_state *st, unsigned int *val)
+{
+ struct spi_transfer t = {
+ .tx_buf = st->tx_buf,
+ .rx_buf = st->rx_buf,
+ .len = 2,
+ };
+ int ret;
+
+ st->tx_buf[0] = AD4000_READ_COMMAND;
+ ret = spi_sync_transfer(st->spi, &t, 1);
+ if (ret < 0)
+ return ret;
+
+ *val = st->tx_buf[1];
+ return ret;
+}
+
+/*
+ * This executes a data sample transfer for when the device connections are
+ * in "3-wire" mode, selected when the adi,sdi-pin device tree property is
+ * absent or set to "high". In this connection mode, the ADC SDI pin is
+ * connected to MOSI or to VIO and ADC CNV pin is connected either to a SPI
+ * controller CS or to a GPIO.
+ * AD4000 series of devices initiate conversions on the rising edge of CNV pin.
+ *
+ * If the CNV pin is connected to an SPI controller CS line (which is by default
+ * active low), the ADC readings would have a latency (delay) of one read.
+ * Moreover, since we also do ADC sampling for filling the buffer on triggered
+ * buffer mode, the timestamps of buffer readings would be disarranged.
+ * To prevent the read latency and reduce the time discrepancy between the
+ * sample read request and the time of actual sampling by the ADC, do a
+ * preparatory transfer to pulse the CS/CNV line.
+ */
+static int ad4000_prepare_3wire_mode_message(struct ad4000_state *st,
+ const struct iio_chan_spec *chan)
+{
+ unsigned int cnv_pulse_time = st->turbo_mode ? AD4000_TQUIET1_NS
+ : AD4000_TCONV_NS;
+ struct spi_transfer *xfers = st->xfers;
+
+ xfers[0].cs_change = 1;
+ xfers[0].cs_change_delay.value = cnv_pulse_time;
+ xfers[0].cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
+
+ xfers[1].rx_buf = &st->scan.data;
+ xfers[1].len = BITS_TO_BYTES(chan->scan_type.storagebits);
+ xfers[1].delay.value = AD4000_TQUIET2_NS;
+ xfers[1].delay.unit = SPI_DELAY_UNIT_NSECS;
+
+ spi_message_init_with_transfers(&st->msg, st->xfers, 2);
+
+ return devm_spi_optimize_message(st->spi, &st->msg);
+}
+
+/*
+ * This executes a data sample transfer for when the device connections are
+ * in "4-wire" mode, selected when the adi,sdi-pin device tree property is
+ * set to "cs". In this connection mode, the controller CS pin is connected to
+ * ADC SDI pin and a GPIO is connected to ADC CNV pin.
+ * The GPIO connected to ADC CNV pin is set outside of the SPI transfer.
+ */
+static int ad4000_prepare_4wire_mode_message(struct ad4000_state *st,
+ const struct iio_chan_spec *chan)
+{
+ unsigned int cnv_to_sdi_time = st->turbo_mode ? AD4000_TQUIET1_NS
+ : AD4000_TCONV_NS;
+ struct spi_transfer *xfers = st->xfers;
+
+ /*
+ * Dummy transfer to cause enough delay between CNV going high and SDI
+ * going low.
+ */
+ xfers[0].cs_off = 1;
+ xfers[0].delay.value = cnv_to_sdi_time;
+ xfers[0].delay.unit = SPI_DELAY_UNIT_NSECS;
+
+ xfers[1].rx_buf = &st->scan.data;
+ xfers[1].len = BITS_TO_BYTES(chan->scan_type.storagebits);
+
+ spi_message_init_with_transfers(&st->msg, st->xfers, 2);
+
+ return devm_spi_optimize_message(st->spi, &st->msg);
+}
+
+static int ad4000_convert_and_acquire(struct ad4000_state *st)
+{
+ int ret;
+
+ /*
+ * In 4-wire mode, the CNV line is held high for the entire conversion
+ * and acquisition process. In other modes, the CNV GPIO is optional
+ * and, if provided, replaces controller CS. If CNV GPIO is not defined
+ * gpiod_set_value_cansleep() has no effect.
+ */
+ gpiod_set_value_cansleep(st->cnv_gpio, 1);
+ ret = spi_sync(st->spi, &st->msg);
+ gpiod_set_value_cansleep(st->cnv_gpio, 0);
+
+ return ret;
+}
+
+static int ad4000_single_conversion(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val)
+{
+ struct ad4000_state *st = iio_priv(indio_dev);
+ u32 sample;
+ int ret;
+
+ ret = ad4000_convert_and_acquire(st);
+ if (ret < 0)
+ return ret;
+
+ if (chan->scan_type.storagebits > 16)
+ sample = be32_to_cpu(st->scan.data.sample_buf32);
+ else
+ sample = be16_to_cpu(st->scan.data.sample_buf16);
+
+ sample >>= chan->scan_type.shift;
+
+ if (chan->scan_type.sign == 's')
+ *val = sign_extend32(sample, chan->scan_type.realbits - 1);
+
+ return IIO_VAL_INT;
+}
+
+static int ad4000_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long info)
+{
+ struct ad4000_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ iio_device_claim_direct_scoped(return -EBUSY, indio_dev)
+ return ad4000_single_conversion(indio_dev, chan, val);
+ unreachable();
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->scale_tbl[st->span_comp][0];
+ *val2 = st->scale_tbl[st->span_comp][1];
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = 0;
+ if (st->span_comp)
+ *val = mult_frac(st->vref_mv, 1, 10);
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4000_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ struct ad4000_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (int *)st->scale_tbl;
+ *length = AD4000_SCALE_OPTIONS * 2;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4000_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, long mask)
+{
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+}
+
+static int ad4000_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val, int val2,
+ long mask)
+{
+ struct ad4000_state *st = iio_priv(indio_dev);
+ unsigned int reg_val;
+ bool span_comp_en;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&st->lock);
+ ret = ad4000_read_reg(st, &reg_val);
+ if (ret < 0)
+ goto err_unlock;
+
+ span_comp_en = val2 == st->scale_tbl[1][1];
+ reg_val &= ~AD4000_CFG_SPAN_COMP;
+ reg_val |= FIELD_PREP(AD4000_CFG_SPAN_COMP, span_comp_en);
+
+ ret = ad4000_write_reg(st, reg_val);
+ if (ret < 0)
+ goto err_unlock;
+
+ st->span_comp = span_comp_en;
+err_unlock:
+ iio_device_release_direct_mode(indio_dev);
+ mutex_unlock(&st->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t ad4000_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ad4000_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ad4000_convert_and_acquire(st);
+ if (ret < 0)
+ goto err_out;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->scan, pf->timestamp);
+
+err_out:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static const struct iio_info ad4000_reg_access_info = {
+ .read_raw = &ad4000_read_raw,
+ .read_avail = &ad4000_read_avail,
+ .write_raw = &ad4000_write_raw,
+ .write_raw_get_fmt = &ad4000_write_raw_get_fmt,
+};
+
+static const struct iio_info ad4000_info = {
+ .read_raw = &ad4000_read_raw,
+};
+
+static int ad4000_config(struct ad4000_state *st)
+{
+ unsigned int reg_val = AD4000_CONFIG_REG_DEFAULT;
+
+ if (device_property_present(&st->spi->dev, "adi,high-z-input"))
+ reg_val |= FIELD_PREP(AD4000_CFG_HIGHZ, 1);
+
+ return ad4000_write_reg(st, reg_val);
+}
+
+static int ad4000_probe(struct spi_device *spi)
+{
+ const struct ad4000_chip_info *chip;
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ad4000_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ chip = spi_get_device_match_data(spi);
+ if (!chip)
+ return -EINVAL;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ ret = devm_regulator_get_enable(dev, "vdd");
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable VDD supply\n");
+
+ ret = devm_regulator_get_enable(dev, "vio");
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable VIO supply\n");
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "ref");
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "Failed to get ref regulator reference\n");
+ st->vref_mv = ret / 1000;
+
+ st->cnv_gpio = devm_gpiod_get_optional(dev, "cnv", GPIOD_OUT_HIGH);
+ if (IS_ERR(st->cnv_gpio))
+ return dev_err_probe(dev, PTR_ERR(st->cnv_gpio),
+ "Failed to get CNV GPIO");
+
+ ret = device_property_match_property_string(dev, "adi,sdi-pin",
+ ad4000_sdi_pin,
+ ARRAY_SIZE(ad4000_sdi_pin));
+ if (ret < 0 && ret != -EINVAL)
+ return dev_err_probe(dev, ret,
+ "getting adi,sdi-pin property failed\n");
+
+ /* Default to usual SPI connections if pin properties are not present */
+ st->sdi_pin = ret == -EINVAL ? AD4000_SDI_MOSI : ret;
+ switch (st->sdi_pin) {
+ case AD4000_SDI_MOSI:
+ indio_dev->info = &ad4000_reg_access_info;
+ indio_dev->channels = &chip->reg_access_chan_spec;
+
+ /*
+ * In "3-wire mode", the ADC SDI line must be kept high when
+ * data is not being clocked out of the controller.
+ * Request the SPI controller to make MOSI idle high.
+ */
+ spi->mode |= SPI_MOSI_IDLE_HIGH;
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return ret;
+
+ ret = ad4000_prepare_3wire_mode_message(st, indio_dev->channels);
+ if (ret)
+ return ret;
+
+ ret = ad4000_config(st);
+ if (ret < 0)
+ dev_warn(dev, "Failed to config device\n");
+
+ break;
+ case AD4000_SDI_VIO:
+ indio_dev->info = &ad4000_info;
+ indio_dev->channels = &chip->chan_spec;
+ ret = ad4000_prepare_3wire_mode_message(st, indio_dev->channels);
+ if (ret)
+ return ret;
+
+ break;
+ case AD4000_SDI_CS:
+ indio_dev->info = &ad4000_info;
+ indio_dev->channels = &chip->chan_spec;
+ ret = ad4000_prepare_4wire_mode_message(st, indio_dev->channels);
+ if (ret)
+ return ret;
+
+ break;
+ default:
+ return dev_err_probe(dev, -EINVAL, "Unrecognized connection mode\n");
+ }
+
+ indio_dev->name = chip->dev_name;
+ indio_dev->num_channels = 1;
+
+ devm_mutex_init(dev, &st->lock);
+
+ st->gain_milli = 1000;
+ if (chip->has_hardware_gain) {
+ if (device_property_present(dev, "adi,gain-milli")) {
+ ret = device_property_read_u16(dev, "adi,gain-milli",
+ &st->gain_milli);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read gain property\n");
+ }
+ }
+
+ ad4000_fill_scale_tbl(st, indio_dev->channels);
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ &iio_pollfunc_store_time,
+ &ad4000_trigger_handler, NULL);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ad4000_id[] = {
+ { "ad4000", (kernel_ulong_t)&ad4000_chip_info },
+ { "ad4001", (kernel_ulong_t)&ad4001_chip_info },
+ { "ad4002", (kernel_ulong_t)&ad4002_chip_info },
+ { "ad4003", (kernel_ulong_t)&ad4003_chip_info },
+ { "ad4004", (kernel_ulong_t)&ad4004_chip_info },
+ { "ad4005", (kernel_ulong_t)&ad4005_chip_info },
+ { "ad4006", (kernel_ulong_t)&ad4006_chip_info },
+ { "ad4007", (kernel_ulong_t)&ad4007_chip_info },
+ { "ad4008", (kernel_ulong_t)&ad4008_chip_info },
+ { "ad4010", (kernel_ulong_t)&ad4010_chip_info },
+ { "ad4011", (kernel_ulong_t)&ad4011_chip_info },
+ { "ad4020", (kernel_ulong_t)&ad4020_chip_info },
+ { "ad4021", (kernel_ulong_t)&ad4021_chip_info },
+ { "ad4022", (kernel_ulong_t)&ad4022_chip_info },
+ { "adaq4001", (kernel_ulong_t)&adaq4001_chip_info },
+ { "adaq4003", (kernel_ulong_t)&adaq4003_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad4000_id);
+
+static const struct of_device_id ad4000_of_match[] = {
+ { .compatible = "adi,ad4000", .data = &ad4000_chip_info },
+ { .compatible = "adi,ad4001", .data = &ad4001_chip_info },
+ { .compatible = "adi,ad4002", .data = &ad4002_chip_info },
+ { .compatible = "adi,ad4003", .data = &ad4003_chip_info },
+ { .compatible = "adi,ad4004", .data = &ad4004_chip_info },
+ { .compatible = "adi,ad4005", .data = &ad4005_chip_info },
+ { .compatible = "adi,ad4006", .data = &ad4006_chip_info },
+ { .compatible = "adi,ad4007", .data = &ad4007_chip_info },
+ { .compatible = "adi,ad4008", .data = &ad4008_chip_info },
+ { .compatible = "adi,ad4010", .data = &ad4010_chip_info },
+ { .compatible = "adi,ad4011", .data = &ad4011_chip_info },
+ { .compatible = "adi,ad4020", .data = &ad4020_chip_info },
+ { .compatible = "adi,ad4021", .data = &ad4021_chip_info },
+ { .compatible = "adi,ad4022", .data = &ad4022_chip_info },
+ { .compatible = "adi,adaq4001", .data = &adaq4001_chip_info },
+ { .compatible = "adi,adaq4003", .data = &adaq4003_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad4000_of_match);
+
+static struct spi_driver ad4000_driver = {
+ .driver = {
+ .name = "ad4000",
+ .of_match_table = ad4000_of_match,
+ },
+ .probe = ad4000_probe,
+ .id_table = ad4000_id,
+};
+module_spi_driver(ad4000_driver);
+
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD4000 ADC driver");
+MODULE_LICENSE("GPL");
--
2.43.0