[PATCH v2 2/6] iio: adc: ad4030: add driver for ad4030-24

Esteban Blanc
2024-12-19T16:11:22Z

This adds a new driver for the Analog Devices INC. AD4030-24 ADC.

The driver implements basic support for the AD4030-24 1 channel
differential ADC with hardware gain and offset control.

Signed-off-by: Esteban Blanc <eblanc@baylibre.com>
---
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 14 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad4030.c | 926 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 942 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index f17ead8c1e7b9abd2ae406494a24e117fb76435a..943c48fc0a75f475049758cf3791ba6d19748a63 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1282,6 +1282,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
+F: drivers/iio/adc/ad4030.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 849c90203071a77ec7d94cec06d4378ece44440b..9677343a3269db6405dfdd4e938423806c891b47 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -33,6 +33,20 @@ config AD4000
To compile this driver as a module, choose M here: the module will be
called ad4000.

+config AD4030
+ tristate "Analog Devices AD4030 ADC Driver"
+ depends on SPI
+ depends on GPIOLIB
+ select REGMAP
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for Analog Devices AD4030 and AD4630 high speed
+ SPI analog to digital converters (ADC).
+
+ To compile this driver as a module, choose M here: the module will be
+ called ad4030.
+
config AD4130
tristate "Analog Device AD4130 ADC Driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index ee19afba62b7fe0a68309c16f3581d98c5b8f653..326536bb672da3d6229b66af13874d122b2f7b94 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -7,6 +7,7 @@
obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
obj-$(CONFIG_AD4000) += ad4000.o
+obj-$(CONFIG_AD4030) += ad4030.o
obj-$(CONFIG_AD4130) += ad4130.o
obj-$(CONFIG_AD4695) += ad4695.o
obj-$(CONFIG_AD7091R) += ad7091r-base.o
diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c
new file mode 100644
index 0000000000000000000000000000000000000000..feb98a0fdbeb3e48cd356d817a5dda6d23f5ed3f
--- /dev/null
+++ b/drivers/iio/adc/ad4030.c
@@ -0,0 +1,926 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD4030 and AD4630 ADC family driver.
+ *
+ * Copyright 2024 Analog Devices, Inc.
+ * Copyright 2024 BayLibre, SAS
+ *
+ * based on code from:
+ * Analog Devices, Inc.
+ * Sergiu Cuciurean <sergiu.cuciurean@analog.com>
+ * Nuno Sa <nuno.sa@analog.com>
+ * Marcelo Schmitt <marcelo.schmitt@analog.com>
+ * Liviu Adace <liviu.adace@analog.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/units.h>
+
+#define AD4030_REG_INTERFACE_CONFIG_A 0x00
+#define AD4030_REG_INTERFACE_CONFIG_A_SW_RESET (BIT(0) | BIT(7))
+#define AD4030_REG_INTERFACE_CONFIG_B 0x01
+#define AD4030_REG_DEVICE_CONFIG 0x02
+#define AD4030_REG_CHIP_TYPE 0x03
+#define AD4030_REG_PRODUCT_ID_L 0x04
+#define AD4030_REG_PRODUCT_ID_H 0x05
+#define AD4030_REG_CHIP_GRADE 0x06
+#define AD4030_REG_CHIP_GRADE_AD4030_24_GRADE 0x10
+#define AD4030_REG_CHIP_GRADE_MASK_CHIP_GRADE GENMASK(7, 3)
+#define AD4030_REG_SCRATCH_PAD 0x0A
+#define AD4030_REG_SPI_REVISION 0x0B
+#define AD4030_REG_VENDOR_L 0x0C
+#define AD4030_REG_VENDOR_H 0x0D
+#define AD4030_REG_STREAM_MODE 0x0E
+#define AD4030_REG_INTERFACE_CONFIG_C 0x10
+#define AD4030_REG_INTERFACE_STATUS_A 0x11
+#define AD4030_REG_EXIT_CFG_MODE 0x14
+#define AD4030_REG_EXIT_CFG_MODE_EXIT_MSK BIT(0)
+#define AD4030_REG_AVG 0x15
+#define AD4030_REG_AVG_MASK_AVG_SYNC BIT(7)
+#define AD4030_REG_AVG_MASK_AVG_VAL GENMASK(4, 0)
+#define AD4030_REG_OFFSET_X0_0 0x16
+#define AD4030_REG_OFFSET_X0_1 0x17
+#define AD4030_REG_OFFSET_X0_2 0x18
+#define AD4030_REG_OFFSET_X1_0 0x19
+#define AD4030_REG_OFFSET_X1_1 0x1A
+#define AD4030_REG_OFFSET_X1_2 0x1B
+#define AD4030_REG_OFFSET_BYTES_NB 3
+#define AD4030_REG_OFFSET_CHAN(ch) (AD4030_REG_OFFSET_X0_2 + \
+ (AD4030_REG_OFFSET_BYTES_NB * \
+ (ch)))
+#define AD4030_REG_GAIN_X0_LSB 0x1C
+#define AD4030_REG_GAIN_X0_MSB 0x1D
+#define AD4030_REG_GAIN_X1_LSB 0x1E
+#define AD4030_REG_GAIN_X1_MSB 0x1F
+#define AD4030_REG_GAIN_MAX_GAIN 1999970
+#define AD4030_REG_GAIN_BYTES_NB 2
+#define AD4030_REG_GAIN_CHAN(ch) (AD4030_REG_GAIN_X0_MSB + \
+ (AD4030_REG_GAIN_BYTES_NB * \
+ (ch)))
+#define AD4030_REG_MODES 0x20
+#define AD4030_REG_MODES_MASK_OUT_DATA_MODE GENMASK(2, 0)
+#define AD4030_REG_MODES_MASK_LANE_MODE GENMASK(7, 6)
+#define AD4030_REG_OSCILATOR 0x21
+#define AD4030_REG_IO 0x22
+#define AD4030_REG_IO_MASK_IO2X BIT(1)
+#define AD4030_REG_PAT0 0x23
+#define AD4030_REG_PAT1 0x24
+#define AD4030_REG_PAT2 0x25
+#define AD4030_REG_PAT3 0x26
+#define AD4030_REG_DIG_DIAG 0x34
+#define AD4030_REG_DIG_ERR 0x35
+
+/* Sequence starting with "1 0 1" to enable reg access */
+#define AD4030_REG_ACCESS 0xA0
+
+#define AD4030_MAX_IIO_SAMPLE_SIZE_BUFFERED BITS_TO_BYTES(64)
+#define AD4030_MAX_HARDWARE_CHANNEL_NB 2
+#define AD4030_MAX_IIO_CHANNEL_NB 5
+#define AD4030_SINGLE_COMMON_BYTE_CHANNELS_MASK 0b10
+/*
+ * This accounts for 1 sample per channel plus one s64 for the timestamp,
+ * aligned on a s64 boundary
+ */
+#define AD4030_MAXIMUM_RX_BUFFER_SIZE \
+ (ALIGN(AD4030_MAX_IIO_SAMPLE_SIZE_BUFFERED * \
+ AD4030_MAX_HARDWARE_CHANNEL_NB, \
+ sizeof(s64)) + sizeof(s64))
+
+#define AD4030_VREF_MIN_UV (4096 * MILLI)
+#define AD4030_VREF_MAX_UV (5000 * MILLI)
+#define AD4030_VIO_THRESHOLD_UV (1400 * MILLI)
+
+#define AD4030_SPI_MAX_XFER_LEN 8
+#define AD4030_SPI_MAX_REG_XFER_SPEED (80 * MEGA)
+#define AD4030_TCNVH_NS 10
+#define AD4030_TCNVL_NS 20
+#define AD4030_TCYC_NS 500
+#define AD4030_TCYC_ADJUSTED_NS (AD4030_TCYC_NS - AD4030_TCNVL_NS)
+#define AD4030_TRESET_PW_NS 50
+
+enum ad4030_out_mode {
+ AD4030_OUT_DATA_MD_DIFF,
+ AD4030_OUT_DATA_MD_16_DIFF_8_COM,
+ AD4030_OUT_DATA_MD_24_DIFF_8_COM,
+ AD4030_OUT_DATA_MD_30_AVERAGED_DIFF,
+ AD4030_OUT_DATA_MD_32_PATTERN
+};
+
+struct ad4030_chip_info {
+ const char *name;
+ const unsigned long *available_masks;
+ const struct iio_chan_spec channels[AD4030_MAX_IIO_CHANNEL_NB];
+ u8 grade;
+ u8 precision_bits;
+ /* Number of hardware channels */
+ int num_voltage_inputs;
+ unsigned int tcyc_ns;
+};
+
+struct ad4030_state {
+ struct spi_device *spi;
+ struct regmap *regmap;
+ const struct ad4030_chip_info *chip;
+ struct gpio_desc *cnv_gpio;
+ int vref_uv;
+ int vio_uv;
+ int offset_avail[3];
+ enum ad4030_out_mode mode;
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the transfer buffers
+ * to live in their own cache lines.
+ */
+ u8 tx_data[AD4030_SPI_MAX_XFER_LEN] __aligned(IIO_DMA_MINALIGN);
+ union {
+ u8 raw[AD4030_MAXIMUM_RX_BUFFER_SIZE];
+ struct {
+ s32 diff;
+ u8 common;
+ };
+ } rx_data;
+};
+
+/*
+ * For a chip with 2 hardware channel this will be used to create 2 common-mode
+ * channels:
+ * - voltage4
+ * - voltage5
+ * As the common-mode channels are after the differential ones, we compute the
+ * channel number like this:
+ * - _idx is the scan_index (the order in the output buffer)
+ * - _ch is the hardware channel number this common-mode channel is related
+ * - _idx - _ch gives us the number of channel in the chip
+ * - _idx - _ch * 2 is the starting number of the common-mode channels, since
+ * for each differential channel there is a common-mode channel
+ * - _idx - _ch * 2 + _ch gives the channel number for this specific common-mode
+ * channel
+ */
+#define AD4030_CHAN_CMO(_idx, _ch) { \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .address = (_ch), \
+ .channel = ((_idx) - (_ch)) * 2 + (_ch), \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .storagebits = 8, \
+ .realbits = 8, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+/*
+ * For a chip with 2 hardware channel this will be used to create 2 differential
+ * channels:
+ * - voltage0-voltage1
+ * - voltage2-voltage3
+ */
+#define AD4030_CHAN_DIFF(_idx, _storage, _real, _shift) { \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_CALIBSCALE) | \
+ BIT(IIO_CHAN_INFO_CALIBBIAS) | \
+ BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS) | \
+ BIT(IIO_CHAN_INFO_CALIBSCALE), \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .address = (_idx), \
+ .channel = (_idx) * 2, \
+ .channel2 = (_idx) * 2 + 1, \
+ .scan_index = (_idx), \
+ .differential = true, \
+ .scan_type = { \
+ .sign = 's', \
+ .storagebits = _storage, \
+ .realbits = _real, \
+ .shift = _shift, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+static int ad4030_spi_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ int ret;
+ struct ad4030_state *st = context;
+ struct spi_transfer xfer = {
+ .tx_buf = st->tx_data,
+ .rx_buf = st->rx_data.raw,
+ .len = reg_size + val_size,
+ .speed_hz = AD4030_SPI_MAX_REG_XFER_SPEED,
+ };
+
+ if (xfer.len > ARRAY_SIZE(st->tx_data) ||
+ xfer.len > ARRAY_SIZE(st->rx_data.raw))
+ return -EINVAL;
+
+ memset(st->tx_data, 0, ARRAY_SIZE(st->tx_data));
+ memcpy(st->tx_data, reg, reg_size);
+
+ ret = spi_sync_transfer(st->spi, &xfer, 1);
+ if (ret)
+ return ret;
+
+ memcpy(val, &st->rx_data.raw[reg_size], val_size);
+
+ return ret;
+}
+
+static int ad4030_spi_write(void *context, const void *data, size_t count)
+{
+ struct ad4030_state *st = context;
+
+ struct spi_transfer xfer = {
+ .tx_buf = st->tx_data,
+ .len = count,
+ .speed_hz = AD4030_SPI_MAX_REG_XFER_SPEED,
+ };
+
+ if (count > ARRAY_SIZE(st->tx_data))
+ return -EINVAL;
+
+ memcpy(st->tx_data, data, count);
+
+ return spi_sync_transfer(st->spi, &xfer, 1);
+}
+
+static const struct regmap_bus ad4030_regmap_bus = {
+ .read = ad4030_spi_read,
+ .write = ad4030_spi_write,
+ .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static const struct regmap_range ad4030_regmap_rd_range[] = {
+ regmap_reg_range(AD4030_REG_INTERFACE_CONFIG_A, AD4030_REG_CHIP_GRADE),
+ regmap_reg_range(AD4030_REG_SCRATCH_PAD, AD4030_REG_STREAM_MODE),
+ regmap_reg_range(AD4030_REG_INTERFACE_CONFIG_C,
+ AD4030_REG_INTERFACE_STATUS_A),
+ regmap_reg_range(AD4030_REG_EXIT_CFG_MODE, AD4030_REG_PAT3),
+ regmap_reg_range(AD4030_REG_DIG_DIAG, AD4030_REG_DIG_ERR),
+};
+
+static const struct regmap_range ad4030_regmap_wr_range[] = {
+ regmap_reg_range(AD4030_REG_CHIP_TYPE, AD4030_REG_CHIP_GRADE),
+ regmap_reg_range(AD4030_REG_SPI_REVISION, AD4030_REG_VENDOR_H),
+};
+
+static const struct regmap_access_table ad4030_regmap_rd_table = {
+ .yes_ranges = ad4030_regmap_rd_range,
+ .n_yes_ranges = ARRAY_SIZE(ad4030_regmap_rd_range),
+};
+
+static const struct regmap_access_table ad4030_regmap_wr_table = {
+ .no_ranges = ad4030_regmap_wr_range,
+ .n_no_ranges = ARRAY_SIZE(ad4030_regmap_wr_range),
+};
+
+static const struct regmap_config ad4030_regmap_config = {
+ .reg_bits = 16,
+ .val_bits = 8,
+ .read_flag_mask = 0x80,
+ .rd_table = &ad4030_regmap_rd_table,
+ .wr_table = &ad4030_regmap_wr_table,
+ .max_register = AD4030_REG_DIG_ERR,
+};
+
+static int ad4030_enter_config_mode(struct ad4030_state *st)
+{
+ st->tx_data[0] = AD4030_REG_ACCESS;
+
+ struct spi_transfer xfer = {
+ .tx_buf = st->tx_data,
+ .len = 1,
+ .speed_hz = AD4030_SPI_MAX_REG_XFER_SPEED,
+ };
+
+ return spi_sync_transfer(st->spi, &xfer, 1);
+}
+
+static int ad4030_exit_config_mode(struct ad4030_state *st)
+{
+ return regmap_write(st->regmap, AD4030_REG_EXIT_CFG_MODE,
+ AD4030_REG_EXIT_CFG_MODE_EXIT_MSK);
+}
+
+static int ad4030_get_chan_scale(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+
+ if (chan->differential) {
+ *val = (st->vref_uv * 2) / MILLI;
+ *val2 = st->chip->precision_bits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+
+ *val = st->vref_uv / 256;
+ return IIO_VAL_INT;
+}
+
+static int ad4030_get_chan_calibscale(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ u16 gain;
+ int ret;
+
+ ret = regmap_bulk_read(st->regmap, AD4030_REG_GAIN_CHAN(chan->address),
+ st->rx_data.raw, AD4030_REG_GAIN_BYTES_NB);
+ if (ret)
+ return ret;
+
+ gain = get_unaligned_be16(st->rx_data.raw);
+
+ /* From datasheet: multiplied output = input × gain word/0x8000 */
+ *val = gain / 0x8000;
+ *val2 = mul_u64_u32_div(gain % 0x8000, NANO, 0x8000);
+
+ return IIO_VAL_INT_PLUS_NANO;
+}
+
+/* Returns the offset where 1 LSB = (VREF/2^precision_bits - 1)/gain */
+static int ad4030_get_chan_calibbias(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = regmap_bulk_read(st->regmap,
+ AD4030_REG_OFFSET_CHAN(chan->address),
+ st->rx_data.raw, AD4030_REG_OFFSET_BYTES_NB);
+ if (ret)
+ return ret;
+
+ switch (st->chip->precision_bits) {
+ case 16:
+ *val = sign_extend32(get_unaligned_be16(st->rx_data.raw), 15);
+ return IIO_VAL_INT;
+
+ case 24:
+ *val = sign_extend32(get_unaligned_be24(st->rx_data.raw), 23);
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4030_set_chan_calibscale(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int gain_int,
+ int gain_frac)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ u64 gain;
+
+ if (gain_int < 0 || gain_frac < 0)
+ return -EINVAL;
+
+ gain = mul_u32_u32(gain_int, MICRO) + gain_frac;
+
+ if (gain > AD4030_REG_GAIN_MAX_GAIN)
+ return -EINVAL;
+
+ put_unaligned_be16(DIV_ROUND_CLOSEST_ULL(gain * 0x8000, MICRO),
+ st->tx_data);
+
+ return regmap_bulk_write(st->regmap,
+ AD4030_REG_GAIN_CHAN(chan->address),
+ st->tx_data, AD4030_REG_GAIN_BYTES_NB);
+}
+
+static int ad4030_set_chan_calibbias(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int offset)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+
+ if (offset < st->offset_avail[0] || offset > st->offset_avail[2])
+ return -EINVAL;
+
+ st->tx_data[2] = 0;
+
+ switch (st->chip->precision_bits) {
+ case 16:
+ put_unaligned_be16(offset, st->tx_data);
+ break;
+
+ case 24:
+ put_unaligned_be24(offset, st->tx_data);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return regmap_bulk_write(st->regmap,
+ AD4030_REG_OFFSET_CHAN(chan->address),
+ st->tx_data, AD4030_REG_OFFSET_BYTES_NB);
+}
+
+static bool ad4030_is_common_byte_asked(struct ad4030_state *st,
+ unsigned int mask)
+{
+ return mask & AD4030_SINGLE_COMMON_BYTE_CHANNELS_MASK;
+}
+
+static int ad4030_set_mode(struct iio_dev *indio_dev, unsigned long mask)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+
+ if (ad4030_is_common_byte_asked(st, mask))
+ st->mode = AD4030_OUT_DATA_MD_24_DIFF_8_COM;
+ else
+ st->mode = AD4030_OUT_DATA_MD_DIFF;
+
+ return regmap_update_bits(st->regmap, AD4030_REG_MODES,
+ AD4030_REG_MODES_MASK_OUT_DATA_MODE,
+ st->mode);
+}
+
+static int ad4030_conversion(struct iio_dev *indio_dev)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ const struct iio_scan_type scan_type = indio_dev->channels->scan_type;
+ unsigned char diff_realbytes = BITS_TO_BYTES(scan_type.realbits);
+ unsigned int bytes_to_read;
+ int ret;
+
+ /* Number of bytes for one differential channel */
+ bytes_to_read = diff_realbytes;
+ /* Add one byte if we are using a differential + common byte mode */
+ bytes_to_read += (st->mode == AD4030_OUT_DATA_MD_24_DIFF_8_COM ||
+ st->mode == AD4030_OUT_DATA_MD_16_DIFF_8_COM) ? 1 : 0;
+ /* Mulitiply by the number of hardware channels */
+ bytes_to_read *= st->chip->num_voltage_inputs;
+
+ gpiod_set_value_cansleep(st->cnv_gpio, 1);
+ ndelay(AD4030_TCNVH_NS);
+ gpiod_set_value_cansleep(st->cnv_gpio, 0);
+ ndelay(st->chip->tcyc_ns);
+
+ ret = spi_read(st->spi, st->rx_data.raw, bytes_to_read);
+ if (ret)
+ return ret;
+
+ if (st->mode != AD4030_OUT_DATA_MD_24_DIFF_8_COM)
+ return 0;
+
+ st->rx_data.common = st->rx_data.raw[diff_realbytes];
+
+ return 0;
+}
+
+static int ad4030_single_conversion(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ad4030_set_mode(indio_dev, BIT(chan->scan_index));
+ if (ret)
+ return ret;
+
+ ret = ad4030_exit_config_mode(st);
+ if (ret)
+ goto out_error;
+
+ ret = ad4030_conversion(indio_dev);
+ if (ret)
+ goto out_error;
+
+ if (chan->differential)
+ *val = st->rx_data.diff;
+ else
+ *val = st->rx_data.common;
+
+ ad4030_enter_config_mode(st);
+
+ return IIO_VAL_INT;
+
+out_error:
+ ad4030_enter_config_mode(st);
+
+ return ret;
+}
+
+static irqreturn_t ad4030_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ad4030_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ad4030_conversion(indio_dev);
+ if (ret)
+ goto out;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, st->rx_data.raw,
+ pf->timestamp);
+
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static const int ad4030_gain_avail[3][2] = {
+ { 0, 0 },
+ { 0, 30518 },
+ { 1, 999969482 },
+};
+
+static int ad4030_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ const int **vals, int *type,
+ int *length, long mask)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *vals = st->offset_avail;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *vals = (void *)ad4030_gain_avail;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_RANGE;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4030_read_raw_dispatch(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ return ad4030_single_conversion(indio_dev, chan, val);
+
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return ad4030_get_chan_calibscale(indio_dev, chan, val, val2);
+
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return ad4030_get_chan_calibbias(indio_dev, chan, val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4030_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long info)
+{
+ int ret;
+
+ if (info == IIO_CHAN_INFO_SCALE)
+ return ad4030_get_chan_scale(indio_dev, chan, val, val2);
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ad4030_read_raw_dispatch(indio_dev, chan, val, val2, info);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+}
+
+static int ad4030_write_raw_dispatch(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return ad4030_set_chan_calibscale(indio_dev, chan, val, val2);
+
+ case IIO_CHAN_INFO_CALIBBIAS:
+ if (val2 != 0)
+ return -EINVAL;
+ return ad4030_set_chan_calibbias(indio_dev, chan, val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4030_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ int ret;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ad4030_write_raw_dispatch(indio_dev, chan, val, val2, info);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+}
+
+static int ad4030_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+ unsigned int writeval, unsigned int *readval)
+{
+ const struct ad4030_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ if (readval)
+ ret = regmap_read(st->regmap, reg, readval);
+ else
+ ret = regmap_write(st->regmap, reg, writeval);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+}
+
+static int ad4030_read_label(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ char *label)
+{
+ if (chan->differential)
+ return sprintf(label, "differential%lu\n", chan->address);
+ return sprintf(label, "common-mode%lu\n", chan->address);
+}
+
+static const struct iio_info ad4030_iio_info = {
+ .read_avail = ad4030_read_avail,
+ .read_raw = ad4030_read_raw,
+ .write_raw = ad4030_write_raw,
+ .debugfs_reg_access = ad4030_reg_access,
+ .read_label = ad4030_read_label,
+};
+
+static int ad4030_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ad4030_set_mode(indio_dev, *indio_dev->active_scan_mask);
+ if (ret)
+ return ret;
+
+ ret = ad4030_exit_config_mode(st);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int ad4030_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ struct ad4030_state *st = iio_priv(indio_dev);
+
+ return ad4030_enter_config_mode(st);
+}
+
+static const struct iio_buffer_setup_ops ad4030_buffer_setup_ops = {
+ .preenable = ad4030_buffer_preenable,
+ .postdisable = ad4030_buffer_postdisable,
+};
+
+static int ad4030_regulators_get(struct ad4030_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ static const char * const ids[] = { "vdd-5v", "vdd-1v8" };
+ int ret;
+
+ ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(ids), ids);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable regulators\n");
+
+ st->vio_uv = devm_regulator_get_enable_read_voltage(dev, "vio");
+ if (st->vio_uv < 0)
+ return dev_err_probe(dev, st->vio_uv,
+ "Failed to enable and read vio voltage\n");
+
+ st->vref_uv = devm_regulator_get_enable_read_voltage(dev, "ref");
+ if (st->vref_uv < 0) {
+ if (st->vref_uv != -ENODEV)
+ return dev_err_probe(dev, st->vref_uv,
+ "Failed to read ref voltage\n");
+
+ /* if not using optional REF, the internal REFIN must be used */
+ st->vref_uv = devm_regulator_get_enable_read_voltage(dev,
+ "refin");
+ if (st->vref_uv < 0)
+ return dev_err_probe(dev, st->vref_uv,
+ "Failed to read refin voltage\n");
+ }
+
+ return 0;
+}
+
+static int ad4030_reset(struct ad4030_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ struct gpio_desc *reset;
+ int ret;
+
+ reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(reset))
+ return dev_err_probe(dev, PTR_ERR(reset),
+ "Failed to get reset GPIO\n");
+
+ if (reset) {
+ ndelay(50);
+ gpiod_set_value_cansleep(reset, 0);
+ } else {
+ ret = ad4030_enter_config_mode(st);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4030_REG_INTERFACE_CONFIG_A,
+ AD4030_REG_INTERFACE_CONFIG_A_SW_RESET);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * From datasheet: "After a [...] reset, no SPI commands or conversions
+ * can be started for 750us"
+ */
+ fsleep(750);
+
+ /* After reset, conversion mode is enabled. Switch to reg access */
+ return ad4030_enter_config_mode(st);
+}
+
+static int ad4030_detect_chip_info(const struct ad4030_state *st)
+{
+ unsigned int grade;
+ int ret;
+
+ ret = regmap_read(st->regmap, AD4030_REG_CHIP_GRADE, &grade);
+ if (ret)
+ return ret;
+
+ grade = FIELD_GET(AD4030_REG_CHIP_GRADE_MASK_CHIP_GRADE, grade);
+ if (grade != st->chip->grade)
+ dev_warn(&st->spi->dev, "Unknown grade(0x%x) for %s\n", grade,
+ st->chip->name);
+
+ return 0;
+}
+
+static int ad4030_config(struct ad4030_state *st)
+{
+ st->offset_avail[0] = (int)BIT(st->chip->precision_bits - 1) * -1;
+ st->offset_avail[1] = 1;
+ st->offset_avail[2] = BIT(st->chip->precision_bits - 1) - 1;
+
+ if (st->vio_uv < AD4030_VIO_THRESHOLD_UV)
+ return regmap_write(st->regmap, AD4030_REG_IO,
+ AD4030_REG_IO_MASK_IO2X);
+
+ return 0;
+}
+
+static int ad4030_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ad4030_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ st->regmap = devm_regmap_init(dev, &ad4030_regmap_bus, st,
+ &ad4030_regmap_config);
+ if (IS_ERR(st->regmap))
+ dev_err_probe(dev, PTR_ERR(st->regmap),
+ "Failed to initialize regmap\n");
+
+ st->chip = spi_get_device_match_data(spi);
+ if (!st->chip)
+ return -EINVAL;
+
+ ret = ad4030_regulators_get(st);
+ if (ret)
+ return ret;
+
+ /*
+ * From datasheet: "Perform a reset no sooner than 3ms after the power
+ * supplies are valid and stable"
+ */
+ fsleep(3000);
+
+ ret = ad4030_reset(st);
+ if (ret)
+ return ret;
+
+ ret = ad4030_detect_chip_info(st);
+ if (ret)
+ return ret;
+
+ ret = ad4030_config(st);
+ if (ret)
+ return ret;
+
+ st->cnv_gpio = devm_gpiod_get(dev, "cnv", GPIOD_OUT_LOW);
+ if (IS_ERR(st->cnv_gpio))
+ return dev_err_probe(dev, PTR_ERR(st->cnv_gpio),
+ "Failed to get cnv gpio\n");
+
+ /*
+ * One hardware channel is split in two software channels when using
+ * common byte mode. Add one more channel for the timestamp.
+ */
+ indio_dev->num_channels = 2 * st->chip->num_voltage_inputs + 1;
+ indio_dev->name = st->chip->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &ad4030_iio_info;
+ indio_dev->channels = st->chip->channels;
+ indio_dev->available_scan_masks = st->chip->available_masks;
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ ad4030_trigger_handler,
+ &ad4030_buffer_setup_ops);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to setup triggered buffer\n");
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const unsigned long ad4030_channel_masks[] = {
+ /* Differential only */
+ BIT(0),
+ /* Differential and common-mode voltage */
+ GENMASK(1, 0),
+ 0,
+};
+
+static const struct ad4030_chip_info ad4030_24_chip_info = {
+ .name = "ad4030-24",
+ .available_masks = ad4030_channel_masks,
+ .channels = {
+ AD4030_CHAN_DIFF(0, 32, 24, 8),
+ AD4030_CHAN_CMO(1, 0),
+ IIO_CHAN_SOFT_TIMESTAMP(2),
+ },
+ .grade = AD4030_REG_CHIP_GRADE_AD4030_24_GRADE,
+ .precision_bits = 24,
+ .num_voltage_inputs = 1,
+ .tcyc_ns = AD4030_TCYC_ADJUSTED_NS,
+};
+
+static const struct spi_device_id ad4030_id_table[] = {
+ { "ad4030-24", (kernel_ulong_t)&ad4030_24_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad4030_id_table);
+
+static const struct of_device_id ad4030_of_match[] = {
+ { .compatible = "adi,ad4030-24", .data = &ad4030_24_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad4030_of_match);
+
+static struct spi_driver ad4030_driver = {
+ .driver = {
+ .name = "ad4030",
+ .of_match_table = ad4030_of_match,
+ },
+ .probe = ad4030_probe,
+ .id_table = ad4030_id_table,
+};
+module_spi_driver(ad4030_driver);
+
+MODULE_AUTHOR("Esteban Blanc <eblanc@baylibre.com>");
+MODULE_DESCRIPTION("Analog Devices AD4630 ADC family driver");
+MODULE_LICENSE("GPL");

--
2.47.0