@@ -1352,6 +1352,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad4170.yaml
+F: drivers/iio/adc/ad4170.c
ANALOG DEVICES INC AD4695 DRIVER
M: Michael Hennerich <michael.hennerich@analog.com>
@@ -70,6 +70,18 @@ config AD4130
To compile this driver as a module, choose M here: the module will be
called ad4130.
+
+config AD4170
+ tristate "Analog Device AD4170 ADC Driver"
+ depends on SPI
+ select REGMAP_SPI
+ help
+ Say yes here to build support for Analog Devices AD4170 SPI analog
+ to digital converters (ADC).
+
+ To compile this driver as a module, choose M here: the module will be
+ called ad4170.
+
config AD4695
tristate "Analog Device AD4695 ADC Driver"
depends on SPI
@@ -11,6 +11,7 @@ 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-$(CONFIG_AD4170) += ad4170.o
obj-$(CONFIG_AD4695) += ad4695.o
obj-$(CONFIG_AD4851) += ad4851.o
obj-$(CONFIG_AD7091R) += ad7091r-base.o
new file mode 100644
@@ -0,0 +1,1553 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2025 Analog Devices, Inc.
+ * Author: Ana-Maria Cusco <ana-maria.cusco@analog.com>
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+
+/*
+ * AD4170 registers
+ * Multibyte register addresses point to the most significant byte which is the
+ * address to use to get the most significant byte first (address accessed is
+ * decremented by one for each data byte)
+ *
+ * Each register address define follows the AD4170_<REG_NAME>_REG form.
+ * Each mask follows the AD4170_<REG_NAME>_<FIELD_NAME> form.
+ * E.g. AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK is for accessing DIG_AUX1_CTRL field
+ * of PIN_MUXING_REG.
+ * Each constant follows the AD4170_<REG_NAME>_<FIELD_NAME>_<FUNCTION> form.
+ * E.g. AD4170_PIN_MUXING_DIG_AUX1_DISABLED is the value written to
+ * DIG_AUX1_CTRL field of PIN_MUXING register to disable DIG_AUX1 pin.
+ * Some register names and register field names are shortened versions of
+ * their datasheet counterpart names to provide better code readability.
+ */
+#define AD4170_CONFIG_A_REG 0x00
+#define AD4170_DATA_24B_REG 0x1E
+#define AD4170_PIN_MUXING_REG 0x69
+#define AD4170_ADC_CTRL_REG 0x71
+#define AD4170_CHAN_EN_REG 0x79
+#define AD4170_CHAN_SETUP_REG(x) (0x81 + 4 * (x))
+#define AD4170_CHAN_MAP_REG(x) (0x83 + 4 * (x))
+#define AD4170_MISC_REG(x) (0xC1 + 14 * (x))
+#define AD4170_AFE_REG(x) (0xC3 + 14 * (x))
+#define AD4170_FILTER_REG(x) (0xC5 + 14 * (x))
+#define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x))
+#define AD4170_OFFSET_REG(x) (0xCA + 14 * (x))
+#define AD4170_GAIN_REG(x) (0xCD + 14 * (x))
+
+#define AD4170_REG_READ_MASK BIT(14)
+
+/* AD4170_CONFIG_A_REG - INTERFACE_CONFIG_A REGISTER */
+#define AD4170_SW_RESET_MSK (BIT(7) | BIT(0))
+
+/* AD4170_PIN_MUXING_REG */
+#define AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK GENMASK(5, 4)
+
+/* AD4170_ADC_CTRL_REG */
+#define AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK BIT(7)
+#define AD4170_ADC_CTRL_MODE_MSK GENMASK(3, 0)
+
+/* AD4170_CHAN_EN_REG */
+#define AD4170_CHAN_EN(ch) BIT(ch)
+
+/* AD4170_CHAN_SETUP_REG */
+#define AD4170_CHAN_SETUP_SETUP_MSK GENMASK(2, 0)
+
+/* AD4170_CHAN_MAP_REG */
+#define AD4170_CHAN_MAP_AINP_MSK GENMASK(12, 8)
+#define AD4170_CHAN_MAP_AINM_MSK GENMASK(4, 0)
+
+/* AD4170_AFE_REG */
+#define AD4170_AFE_REF_BUF_M_MSK GENMASK(11, 10)
+#define AD4170_AFE_REF_BUF_P_MSK GENMASK(9, 8)
+#define AD4170_AFE_REF_SELECT_MSK GENMASK(6, 5)
+#define AD4170_AFE_BIPOLAR_MSK BIT(4)
+#define AD4170_AFE_PGA_GAIN_MSK GENMASK(3, 0)
+
+/* AD4170 register constants */
+
+/* AD4170_CHAN_MAP_REG constants */
+#define AD4170_CHAN_MAP_AIN(x) (x)
+#define AD4170_CHAN_MAP_TEMP_SENSOR 17
+#define AD4170_CHAN_MAP_AVDD_AVSS_P 18
+#define AD4170_CHAN_MAP_AVDD_AVSS_N 18
+#define AD4170_CHAN_MAP_IOVDD_DGND_P 19
+#define AD4170_CHAN_MAP_IOVDD_DGND_N 19
+#define AD4170_CHAN_MAP_AVSS 23
+#define AD4170_CHAN_MAP_DGND 24
+#define AD4170_CHAN_MAP_REFIN1_P 25
+#define AD4170_CHAN_MAP_REFIN1_N 26
+#define AD4170_CHAN_MAP_REFIN2_P 27
+#define AD4170_CHAN_MAP_REFIN2_N 28
+#define AD4170_CHAN_MAP_REFOUT 29
+
+/* AD4170_PIN_MUXING_REG constants */
+#define AD4170_PIN_MUXING_DIG_AUX1_DISABLED 0x0
+#define AD4170_PIN_MUXING_DIG_AUX1_RDY 0x1
+
+/* AD4170_ADC_CTRL_REG constants */
+#define AD4170_ADC_CTRL_MODE_SINGLE 0x4
+#define AD4170_ADC_CTRL_MODE_IDLE 0x7
+
+/* Device properties and auxiliary constants */
+
+#define AD4170_NUM_ANALOG_PINS 9
+#define AD4170_MAX_CHANNELS 16
+#define AD4170_MAX_ANALOG_PINS 8
+#define AD4170_MAX_SETUPS 8
+#define AD4170_INVALID_SETUP 9
+#define AD4170_SPI_MAX_XFER_LEN 6
+
+#define AD4170_INT_REF_2_5V 2500000
+
+/* Internal and external clock properties */
+#define AD4170_INT_CLOCK_16MHZ (16 * HZ_PER_MHZ)
+
+#define AD4170_NUM_PGA_OPTIONS 10
+
+#define AD4170_GAIN_REG_DEFAULT 0x555555
+
+/* Analog pin functions */
+#define AD4170_PIN_UNASIGNED 0x00
+
+static const unsigned int ad4170_reg_size[] = {
+ [AD4170_CONFIG_A_REG] = 1,
+ [AD4170_DATA_24B_REG] = 3,
+ [AD4170_PIN_MUXING_REG] = 2,
+ [AD4170_ADC_CTRL_REG] = 2,
+ [AD4170_CHAN_EN_REG] = 2,
+ /*
+ * CHANNEL_SETUP and CHANNEL_MAP register are all 2 byte size each and
+ * their addresses are interleaved such that we have CHANNEL_SETUP0
+ * address followed by CHANNEL_MAP0 address, followed by CHANNEL_SETUP1,
+ * and so on until CHANNEL_MAP15.
+ * Thus, initialize the register size for them only once.
+ */
+ [AD4170_CHAN_SETUP_REG(0) ... AD4170_CHAN_MAP_REG(AD4170_MAX_CHANNELS - 1)] = 2,
+ /*
+ * MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN register addresses are
+ * also interleaved but MISC, AFE, FILTER, FILTER_FS, OFFSET are 16-bit
+ * while OFFSET, GAIN are 24-bit registers so we can't init them all to
+ * the same size.
+ */
+ [AD4170_MISC_REG(0) ... AD4170_FILTER_FS_REG(0)] = 2,
+ [AD4170_MISC_REG(1) ... AD4170_FILTER_FS_REG(1)] = 2,
+ [AD4170_MISC_REG(2) ... AD4170_FILTER_FS_REG(2)] = 2,
+ [AD4170_MISC_REG(3) ... AD4170_FILTER_FS_REG(3)] = 2,
+ [AD4170_MISC_REG(4) ... AD4170_FILTER_FS_REG(4)] = 2,
+ [AD4170_MISC_REG(5) ... AD4170_FILTER_FS_REG(5)] = 2,
+ [AD4170_MISC_REG(6) ... AD4170_FILTER_FS_REG(6)] = 2,
+ [AD4170_MISC_REG(7) ... AD4170_FILTER_FS_REG(7)] = 2,
+ [AD4170_OFFSET_REG(0) ... AD4170_GAIN_REG(0)] = 3,
+ [AD4170_OFFSET_REG(1) ... AD4170_GAIN_REG(1)] = 3,
+ [AD4170_OFFSET_REG(2) ... AD4170_GAIN_REG(2)] = 3,
+ [AD4170_OFFSET_REG(3) ... AD4170_GAIN_REG(3)] = 3,
+ [AD4170_OFFSET_REG(4) ... AD4170_GAIN_REG(4)] = 3,
+ [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3,
+ [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3,
+ [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3,
+};
+
+enum ad4170_ref_buf {
+ AD4170_REF_BUF_PRE, /* Pre-charge referrence buffer */
+ AD4170_REF_BUF_FULL, /* Full referrence buffering */
+ AD4170_REF_BUF_BYPASS /* Bypass referrence buffering */
+};
+
+enum ad4170_ref_select {
+ AD4170_REF_REFIN1,
+ AD4170_REF_REFIN2,
+ AD4170_REF_REFOUT,
+ AD4170_REF_AVDD
+};
+
+enum ad4170_regulator {
+ AD4170_AVDD_SUP,
+ AD4170_AVSS_SUP,
+ AD4170_IOVDD_SUP,
+ AD4170_REFIN1P_SUP,
+ AD4170_REFIN1N_SUP,
+ AD4170_REFIN2P_SUP,
+ AD4170_REFIN2N_SUP,
+ AD4170_MAX_SUP
+};
+
+enum ad4170_int_pin_sel {
+ AD4170_INT_PIN_SDO,
+ AD4170_INT_PIN_DIG_AUX1,
+};
+
+static const char * const ad4170_int_pin_names[] = {
+ [AD4170_INT_PIN_SDO] = "sdo",
+ [AD4170_INT_PIN_DIG_AUX1] = "dig_aux1",
+};
+
+struct ad4170_chip_info {
+ const char *name;
+};
+
+static const struct ad4170_chip_info ad4170_chip_info = {
+ .name = "ad4170",
+};
+
+static const struct ad4170_chip_info ad4190_chip_info = {
+ .name = "ad4190",
+};
+
+static const struct ad4170_chip_info ad4195_chip_info = {
+ .name = "ad4195",
+};
+
+/*
+ * There are 8 of each MISC, AFE, FILTER, FILTER_FS, OFFSET, and GAIN
+ * configuration registers. That is, there are 8 miscellaneous registers, MISC0
+ * to MISC7. Each MISC register is associated with a setup; MISCN is associated
+ * with setup number N. The other 5 above mentioned types of registers have
+ * analogous structure. A setup is a set of those registers. For example,
+ * setup 1 comprises of MISC1, AFE1, FILTER1, FILTER_FS1, OFFSET1, and GAIN1
+ * registers. Also, there are 16 CHANNEL_SETUP registers (CHANNEL_SETUP0 to
+ * CHANNEL_SETUP15). Each channel setup is associated with one of the 8 possible
+ * setups. Thus, AD4170 can support up to 16 channels but, since there are only
+ * 8 available setups, channels must share settings if more than 8 channels are
+ * configured.
+ *
+ * If this struct is modified, ad4170_setup_eq() will probably need to be
+ * updated too.
+ */
+struct ad4170_setup {
+ u16 misc;
+ u16 afe;
+ u16 filter;
+ u16 filter_fs;
+ u32 offset; /* For calibration purposes */
+ u32 gain; /* For calibration purposes */
+};
+
+struct ad4170_setup_info {
+ struct ad4170_setup setup;
+ unsigned int enabled_channels;
+ unsigned int channels;
+};
+
+struct ad4170_chan_info {
+ unsigned int input_range_uv;
+ unsigned int setup_num; /* Index to access state setup_infos array */
+ struct ad4170_setup setup; /* cached setup */
+ int offset_tbl[10];
+ u32 scale_tbl[10][2];
+ bool initialized;
+ bool enabled;
+};
+
+struct ad4170_state {
+ struct mutex lock; /* Protect read-modify-write and multi write sequences */
+ int vrefs_uv[AD4170_MAX_SUP];
+ u32 mclk_hz;
+ struct ad4170_setup_info setup_infos[AD4170_MAX_SETUPS];
+ struct iio_chan_spec chans[AD4170_MAX_CHANNELS];
+ struct ad4170_chan_info chan_infos[AD4170_MAX_CHANNELS];
+ struct spi_device *spi;
+ struct regmap *regmap;
+ int pins_fn[AD4170_NUM_ANALOG_PINS];
+ u32 int_pin_sel;
+ struct completion completion;
+ /*
+ * DMA (thus cache coherency maintenance) requires the transfer buffers
+ * to live in their own cache lines.
+ */
+ u8 tx_buf[AD4170_SPI_MAX_XFER_LEN] __aligned(IIO_DMA_MINALIGN);
+ u8 rx_buf[4];
+};
+
+static int ad4170_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ if (readval)
+ return regmap_read(st->regmap, reg, readval);
+ else
+ return regmap_write(st->regmap, reg, writeval);
+}
+
+static int ad4170_get_reg_size(struct ad4170_state *st, unsigned int reg,
+ unsigned int *size)
+{
+ if (reg >= ARRAY_SIZE(ad4170_reg_size))
+ return -EINVAL;
+
+ *size = ad4170_reg_size[reg];
+
+ return 0;
+}
+
+static int ad4170_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct ad4170_state *st = context;
+ unsigned int size;
+ int ret;
+
+ ret = ad4170_get_reg_size(st, reg, &size);
+ if (ret)
+ return ret;
+
+ put_unaligned_be16(reg, st->tx_buf);
+ switch (size) {
+ case 3:
+ put_unaligned_be24(val, &st->tx_buf[2]);
+ break;
+ case 2:
+ put_unaligned_be16(val, &st->tx_buf[2]);
+ break;
+ case 1:
+ st->tx_buf[2] = val;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return spi_write(st->spi, st->tx_buf, size + 2);
+}
+
+static int ad4170_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+ struct ad4170_state *st = context;
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = st->tx_buf,
+ .len = 2,
+ },
+ {
+ .rx_buf = st->rx_buf,
+ },
+ };
+ unsigned int size;
+ int ret;
+
+ ret = ad4170_get_reg_size(st, reg, &size);
+ if (ret)
+ return ret;
+
+ put_unaligned_be16(AD4170_REG_READ_MASK | reg, st->tx_buf);
+ t[1].len = size;
+
+ ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+ if (ret)
+ return ret;
+
+ switch (size) {
+ case 3:
+ *val = get_unaligned_be24(st->rx_buf);
+ return 0;
+ case 2:
+ *val = get_unaligned_be16(st->rx_buf);
+ return 0;
+ case 1:
+ *val = st->rx_buf[0];
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct regmap_config ad4170_regmap_config = {
+ .reg_read = ad4170_reg_read,
+ .reg_write = ad4170_reg_write,
+};
+
+static bool ad4170_setup_eq(struct ad4170_setup *a, struct ad4170_setup *b)
+{
+ /*
+ * The use of static_assert() here is to make sure that the comparison
+ * is adapted whenever struct ad4170_setup is changed.
+ */
+ static_assert(sizeof(*a) ==
+ sizeof(struct {
+ u16 misc;
+ u16 afe;
+ u16 filter;
+ u16 filter_fs;
+ u32 offset;
+ u32 gain;
+ }));
+
+ if (a->misc != b->misc ||
+ a->afe != b->afe ||
+ a->filter != b->filter ||
+ a->filter_fs != b->filter_fs ||
+ a->offset != b->offset ||
+ a->gain != b->gain)
+ return false;
+
+ return true;
+}
+
+static int ad4170_find_setup(struct ad4170_state *st,
+ struct ad4170_setup *target_setup,
+ unsigned int *setup_num, bool *overwrite)
+{
+ unsigned int i;
+
+ *setup_num = AD4170_INVALID_SETUP;
+ *overwrite = false;
+
+ for (i = 0; i < AD4170_MAX_SETUPS; i++) {
+ struct ad4170_setup_info *setup_info = &st->setup_infos[i];
+
+ /* Immediately accept a matching setup. */
+ if (ad4170_setup_eq(target_setup, &setup_info->setup)) {
+ *setup_num = i;
+ return 0;
+ }
+
+ /* Ignore all setups which are used by enabled channels. */
+ if (setup_info->enabled_channels)
+ continue;
+
+ /* Find the least used slot. */
+ if (*setup_num == AD4170_INVALID_SETUP ||
+ setup_info->channels < st->setup_infos[*setup_num].channels)
+ *setup_num = i;
+ }
+
+ if (*setup_num == AD4170_INVALID_SETUP)
+ return -EINVAL;
+
+ *overwrite = true;
+ return 0;
+}
+
+static void ad4170_unlink_channel(struct ad4170_state *st, unsigned int channel)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[channel];
+ struct ad4170_setup_info *setup_info = &st->setup_infos[chan_info->setup_num];
+
+ chan_info->setup_num = AD4170_INVALID_SETUP;
+ setup_info->channels--;
+}
+
+static int ad4170_unlink_setup(struct ad4170_state *st, unsigned int setup_num)
+{
+ unsigned int i;
+
+ for (i = 0; i < AD4170_MAX_CHANNELS; i++) {
+ struct ad4170_chan_info *chan_info = &st->chan_infos[i];
+
+ if (!chan_info->initialized || chan_info->setup_num != setup_num)
+ continue;
+
+ ad4170_unlink_channel(st, i);
+ }
+ return 0;
+}
+
+static int ad4170_link_channel_setup(struct ad4170_state *st,
+ unsigned int chan_addr,
+ unsigned int setup_num)
+{
+ struct ad4170_setup_info *setup_info = &st->setup_infos[setup_num];
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ int ret;
+
+ ret = regmap_update_bits(st->regmap, AD4170_CHAN_SETUP_REG(chan_addr),
+ AD4170_CHAN_SETUP_SETUP_MSK,
+ FIELD_PREP(AD4170_CHAN_SETUP_SETUP_MSK, setup_num));
+ if (ret)
+ return ret;
+
+ chan_info->setup_num = setup_num;
+ setup_info->channels++;
+ return 0;
+}
+
+/*
+ * Sets the ADC operating mode. Supported modes are
+ * - Single conversion mode
+ * - Idle mode
+ */
+static int ad4170_set_mode(struct ad4170_state *st, unsigned int mode)
+{
+ return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MODE_MSK,
+ FIELD_PREP(AD4170_ADC_CTRL_MODE_MSK, mode));
+}
+
+static int ad4170_write_setup(struct ad4170_state *st, unsigned int setup_num,
+ struct ad4170_setup *setup)
+{
+ int ret;
+
+ /*
+ * It is recommended to place the ADC in standby mode or idle mode to
+ * write to OFFSET and GAIN registers.
+ */
+ ret = ad4170_set_mode(st, AD4170_ADC_CTRL_MODE_IDLE);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_MISC_REG(setup_num), setup->misc);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_AFE_REG(setup_num), setup->afe);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_FILTER_REG(setup_num),
+ setup->filter);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_FILTER_FS_REG(setup_num),
+ setup->filter_fs);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_OFFSET_REG(setup_num),
+ setup->offset);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4170_GAIN_REG(setup_num), setup->gain);
+ if (ret)
+ return ret;
+
+ memcpy(&st->setup_infos[setup_num].setup, setup, sizeof(*setup));
+ return 0;
+}
+
+static int ad4170_write_channel_setup(struct ad4170_state *st,
+ unsigned int chan_addr, bool on_enable)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ bool overwrite;
+ int setup_num;
+ int ret;
+
+ /*
+ * Similar to AD4130 driver, the following cases need to be handled.
+ *
+ * 1. Enabled and linked channel with setup changes:
+ * - Find a setup. If not possible, return error.
+ * - Unlink channel from current setup.
+ * - If the setup found has only disabled channels linked to it,
+ * unlink all channels, and write the new setup to it.
+ * - Link channel to new setup.
+ *
+ * 2. Soon to be enabled and unlinked channel:
+ * - Find a setup. If not possible, return error.
+ * - If the setup found has only disabled channels linked to it,
+ * unlink all channels, and write the new setup to it.
+ * - Link channel to the setup.
+ *
+ * 3. Disabled and linked channel with setup changes:
+ * - Unlink channel from current setup.
+ *
+ * 4. Soon to be enabled and linked channel:
+ * 5. Disabled and unlinked channel with setup changes:
+ * - Do nothing.
+ */
+
+ /* Cases 3, 4, and 5 */
+ if (chan_info->setup_num != AD4170_INVALID_SETUP) {
+ /* Case 4 */
+ if (on_enable)
+ return 0;
+
+ /* Case 3 */
+ if (!chan_info->enabled) {
+ ad4170_unlink_channel(st, chan_addr);
+ return 0;
+ }
+ } else if (!on_enable && !chan_info->enabled) {
+ /* Case 5 */
+ return 0;
+ }
+
+ /* Cases 1 & 2 */
+ ret = ad4170_find_setup(st, &chan_info->setup, &setup_num, &overwrite);
+ if (ret)
+ return ret;
+
+ if (chan_info->setup_num != AD4170_INVALID_SETUP)
+ /* Case 1 */
+ ad4170_unlink_channel(st, chan_addr);
+
+ if (overwrite) {
+ ret = ad4170_unlink_setup(st, setup_num);
+ if (ret)
+ return ret;
+
+ ret = ad4170_write_setup(st, setup_num, &chan_info->setup);
+ if (ret)
+ return ret;
+ }
+
+ return ad4170_link_channel_setup(st, chan_addr, setup_num);
+}
+
+static int ad4170_set_channel_enable(struct ad4170_state *st,
+ unsigned int chan_addr, bool status)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan_addr];
+ struct ad4170_setup_info *setup_info;
+ int ret;
+
+ if (chan_info->enabled == status)
+ return 0;
+
+ if (status) {
+ ret = ad4170_write_channel_setup(st, chan_addr, true);
+ if (ret)
+ return ret;
+ }
+
+ setup_info = &st->setup_infos[chan_info->setup_num];
+
+ ret = regmap_update_bits(st->regmap, AD4170_CHAN_EN_REG,
+ AD4170_CHAN_EN(chan_addr),
+ status ? AD4170_CHAN_EN(chan_addr) : 0);
+ if (ret)
+ return ret;
+
+ setup_info->enabled_channels += status ? 1 : -1;
+ chan_info->enabled = status;
+ return 0;
+}
+
+static const struct iio_chan_spec ad4170_channel_template = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .differential = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),
+ .scan_type = {
+ .realbits = 24,
+ .storagebits = 32,
+ .endianness = IIO_BE,
+ },
+};
+
+/*
+ * Receives the number of a multiplexed AD4170 input (ain_n), and stores the
+ * voltage (in µV) of the specified input into ain_voltage. If the input number
+ * is a ordinary analog input (AIN0 to AIN8), stores zero into ain_voltage.
+ * If a voltage regulator required by a special input is unavailable, return
+ * error code. Return 0 on success.
+ */
+static int ad4170_get_ain_voltage_uv(struct ad4170_state *st, int ain_n,
+ int *ain_voltage)
+{
+ struct device *dev = &st->spi->dev;
+ int v_diff;
+
+ *ain_voltage = 0;
+ if (ain_n <= AD4170_CHAN_MAP_TEMP_SENSOR)
+ return 0;
+
+ switch (ain_n) {
+ case AD4170_CHAN_MAP_AVDD_AVSS_N:
+ v_diff = st->vrefs_uv[AD4170_AVDD_SUP] - st->vrefs_uv[AD4170_AVSS_SUP];
+ *ain_voltage = v_diff / 5;
+ return 0;
+ case AD4170_CHAN_MAP_IOVDD_DGND_N:
+ *ain_voltage = st->vrefs_uv[AD4170_IOVDD_SUP] / 5;
+ return 0;
+ case AD4170_CHAN_MAP_AVSS:
+ *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_DGND:
+ *ain_voltage = 0;
+ return 0;
+ case AD4170_CHAN_MAP_REFIN1_P:
+ if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN+ but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN1P_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN1_N:
+ if (st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN- but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN1N_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN2_P:
+ if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN2+ but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN2P_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFIN2_N:
+ if (st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "input set to REFIN2- but ref not provided\n");
+
+ *ain_voltage = st->vrefs_uv[AD4170_REFIN2N_SUP];
+ return 0;
+ case AD4170_CHAN_MAP_REFOUT:
+ /* REFOUT is 2.5V relative to AVSS so take that into account */
+ *ain_voltage = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_validate_channel_input(struct ad4170_state *st, int pin, bool com)
+{
+ /* Check common-mode input pin is mapped to a special input. */
+ if (com && (pin < AD4170_CHAN_MAP_AVDD_AVSS_P || pin > AD4170_CHAN_MAP_REFOUT))
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Invalid common-mode input pin number. %d\n",
+ pin);
+
+ /* Check differential input pin is mapped to a analog input pin. */
+ if (!com && pin > AD4170_MAX_ANALOG_PINS)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Invalid analog input pin number. %d\n",
+ pin);
+
+ return 0;
+}
+
+/*
+ * Verifies whether the channel input configuration is valid by checking the
+ * input numbers.
+ * Returns 0 on valid channel input configuration. -EINVAL otherwise.
+ */
+static int ad4170_validate_channel(struct ad4170_state *st,
+ struct iio_chan_spec const *chan)
+{
+ int ret;
+
+ ret = ad4170_validate_channel_input(st, chan->channel, false);
+ if (ret)
+ return ret;
+
+ return ad4170_validate_channel_input(st, chan->channel2,
+ !chan->differential);
+}
+
+/*
+ * Verifies whether the channel configuration is valid by checking the provided
+ * input type, polarity, and voltage references result in a sane input range.
+ * Returns negative error code on failure.
+ */
+static int ad4170_get_input_range(struct ad4170_state *st,
+ struct iio_chan_spec const *chan,
+ unsigned int ch_reg, unsigned int ref_sel)
+{
+ bool bipolar = chan->scan_type.sign == 's';
+ struct device *dev = &st->spi->dev;
+ int refp, refn, ain_voltage, ret;
+
+ switch (ref_sel) {
+ case AD4170_REF_REFIN1:
+ if (st->vrefs_uv[AD4170_REFIN1P_SUP] == -ENODEV ||
+ st->vrefs_uv[AD4170_REFIN1N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "REFIN± selected but not provided\n");
+
+ refp = st->vrefs_uv[AD4170_REFIN1P_SUP];
+ refn = st->vrefs_uv[AD4170_REFIN1N_SUP];
+ break;
+ case AD4170_REF_REFIN2:
+ if (st->vrefs_uv[AD4170_REFIN2P_SUP] == -ENODEV ||
+ st->vrefs_uv[AD4170_REFIN2N_SUP] == -ENODEV)
+ return dev_err_probe(dev, -ENODEV,
+ "REFIN2± selected but not provided\n");
+
+ refp = st->vrefs_uv[AD4170_REFIN2P_SUP];
+ refn = st->vrefs_uv[AD4170_REFIN2N_SUP];
+ break;
+ case AD4170_REF_AVDD:
+ refp = st->vrefs_uv[AD4170_AVDD_SUP];
+ refn = st->vrefs_uv[AD4170_AVSS_SUP];
+ break;
+ case AD4170_REF_REFOUT:
+ /* REFOUT is 2.5 V relative to AVSS */
+ refp = st->vrefs_uv[AD4170_AVSS_SUP] + AD4170_INT_REF_2_5V;
+ refn = st->vrefs_uv[AD4170_AVSS_SUP];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * Find out the analog input range from the channel type, polarity, and
+ * voltage reference selection.
+ * AD4170 channels are either differential or pseudo-differential.
+ * Diff input voltage range: −VREF/gain to +VREF/gain (datasheet page 6)
+ * Pseudo-diff input voltage range: 0 to VREF/gain (datasheet page 6)
+ */
+ if (chan->differential) {
+ if (!bipolar)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Channel %u differential unipolar\n",
+ ch_reg);
+
+ /*
+ * Differential bipolar channel.
+ * avss-supply is never above 0V.
+ * Assuming refin1n-supply not above 0V.
+ * Assuming refin2n-supply not above 0V.
+ */
+ return refp + abs(refn);
+ }
+ /*
+ * Some configurations can lead to invalid setups.
+ * For example, if AVSS = -2.5V, REF_SELECT set to REFOUT (REFOUT/AVSS),
+ * and pseudo-diff channel configuration set, then the input range
+ * should go from 0V to +VREF (single-ended - datasheet pg 10), but
+ * REFOUT/AVSS range would be -2.5V to 0V.
+ * Check the positive reference is higher than 0V for pseudo-diff
+ * channels.
+ */
+ if (refp <= 0)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "REF+ <= GND for pseudo-diff chan %u\n",
+ ch_reg);
+
+ if (bipolar)
+ return refp;
+
+ /*
+ * Pseudo-differential unipolar channel.
+ * Input expected to swing from IN- to +VREF.
+ */
+ ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ain_voltage);
+ if (ret)
+ return ret;
+
+ if (refp - ain_voltage <= 0)
+ return dev_err_probe(&st->spi->dev, -EINVAL,
+ "Negative input >= REF+ for pseudo-diff chan %u\n",
+ ch_reg);
+
+ return refp - ain_voltage;
+}
+
+static int __ad4170_read_sample(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ unsigned long settling_time_ms;
+ int ret;
+
+ reinit_completion(&st->completion);
+ ret = ad4170_set_mode(st, AD4170_ADC_CTRL_MODE_SINGLE);
+ if (ret)
+ return ret;
+
+ /*
+ * When a channel is manually selected by the user, the ADC needs an
+ * extra time to provide the first stable conversion. The ADC settling
+ * time depends on the filter type, filter frequency, and ADC clock
+ * frequency (see datasheet page 53). The maximum settling time among
+ * all filter configurations is 6291164 / fCLK. Use that formula to wait
+ * for sufficient time whatever the filter configuration may be.
+ */
+ settling_time_ms = DIV_ROUND_UP(6291164 * MILLI, st->mclk_hz);
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(settling_time_ms));
+ if (!ret)
+ dev_dbg(&st->spi->dev,
+ "No Data Ready signal. Reading after delay.\n");
+
+ ret = regmap_read(st->regmap, AD4170_DATA_24B_REG, val);
+ if (ret)
+ return ret;
+
+ if (chan->scan_type.sign == 's')
+ *val = sign_extend32(*val, chan->scan_type.realbits - 1);
+
+ return 0;
+}
+
+static int ad4170_read_sample(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ int ret, ret2;
+
+ guard(mutex)(&st->lock);
+ /*
+ * The ADC sequences through all enabled channels. That can lead to
+ * incorrect channel being sampled if a previous read would have left a
+ * different channel enabled. Thus, always enable and disable the
+ * channel on single-shot read.
+ */
+ ret = ad4170_set_channel_enable(st, chan->address, true);
+ if (ret)
+ return ret;
+
+ ret = __ad4170_read_sample(indio_dev, chan, val);
+ if (ret) {
+ dev_err(dev, "failed to read sample: %d\n", ret);
+
+ ret2 = ad4170_set_channel_enable(st, chan->address, false);
+ if (ret2)
+ dev_err(dev, "failed to disable channel: %d\n", ret2);
+
+ return ret;
+ }
+
+ ret = ad4170_set_channel_enable(st, chan->address, false);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+}
+
+static int ad4170_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ unsigned int pga;
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = ad4170_read_sample(indio_dev, chan, val);
+ iio_device_release_direct(indio_dev);
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
+ *val = chan_info->scale_tbl[pga][0];
+ *val2 = chan_info->scale_tbl[pga][1];
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OFFSET:
+ pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
+ *val = chan_info->offset_tbl[pga];
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_fill_scale_tbl(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct device *dev = &st->spi->dev;
+ int bipolar = chan->scan_type.sign == 's' ? 1 : 0;
+ int precision_bits = chan->scan_type.realbits;
+ int pga, ainm_voltage, ret;
+ unsigned long long offset;
+
+ ainm_voltage = 0;
+ ret = ad4170_get_ain_voltage_uv(st, chan->channel2, &ainm_voltage);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to fill scale table\n");
+
+ for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
+ u64 nv;
+ unsigned int lshift, rshift;
+
+ /*
+ * The PGA options are numbered from 0 to 9, with option 0 being
+ * a gain of 2^0 (no actual gain), and 7 meaning a gain of 2^7.
+ * Option 8, though, sets a gain of 0.5, so the input signal can
+ * be attenuated by 2 rather than amplified. Option 9, allows
+ * the signal to bypass the PGA circuitry (no gain).
+ *
+ * The scale factor to get ADC output codes to values in mV
+ * units is given by:
+ * _scale = (input_range / gain) / 2^precision
+ * AD4170 gain is a power of 2 so the above can be written as
+ * _scale = input_range / 2^(precision + gain)
+ * Keep the input range in µV to avoid truncating the less
+ * significan bits when right shifting it so to preserve scale
+ * precision.
+ */
+ nv = (u64)chan_info->input_range_uv * NANO;
+ lshift = !!(pga & BIT(3)); /* handle options 8 and 9 */
+ rshift = precision_bits - bipolar + (pga & GENMASK(2, 0)) - lshift;
+ chan_info->scale_tbl[pga][0] = 0;
+ chan_info->scale_tbl[pga][1] = div_u64(nv >> rshift, MILLI);
+
+ /*
+ * If the negative input is not at GND, the conversion result
+ * (which is relative to IN-) will be offset by the level at IN-.
+ * Use the scale factor the other way around to go from a known
+ * voltage to the corresponding ADC output code.
+ * With that, we are able to get to what would be the output
+ * code for the voltage at the negative input.
+ * If the negative input is not fixed, there is no offset.
+ */
+ offset = ((unsigned long long)abs(ainm_voltage)) * MICRO;
+ offset = DIV_ROUND_CLOSEST_ULL(offset, chan_info->scale_tbl[pga][1]);
+
+ /*
+ * After divided by the scale, offset will always fit into 31
+ * bits. For _raw + _offset to be relative to GND, the value
+ * provided as _offset is of opposite sign than the real offset.
+ */
+ if (ainm_voltage > 0)
+ chan_info->offset_tbl[pga] = -(int)(offset);
+ else
+ chan_info->offset_tbl[pga] = (int)(offset);
+ }
+ return 0;
+}
+
+static int ad4170_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (int *)chan_info->scale_tbl;
+ *length = ARRAY_SIZE(chan_info->scale_tbl) * 2;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_set_pga(struct ad4170_state *st,
+ struct iio_chan_spec const *chan, int val, int val2)
+{
+ struct ad4170_chan_info *chan_info = &st->chan_infos[chan->address];
+ struct ad4170_setup *setup = &chan_info->setup;
+ unsigned int old_pga = FIELD_GET(AD4170_AFE_PGA_GAIN_MSK, setup->afe);
+ unsigned int pga;
+ int ret;
+
+ for (pga = 0; pga < AD4170_NUM_PGA_OPTIONS; pga++) {
+ if (val == chan_info->scale_tbl[pga][0] &&
+ val2 == chan_info->scale_tbl[pga][1])
+ break;
+ }
+
+ if (pga == AD4170_NUM_PGA_OPTIONS)
+ return -EINVAL;
+
+ if (pga == old_pga)
+ return 0;
+
+ guard(mutex)(&st->lock);
+ setup->afe &= ~AD4170_AFE_PGA_GAIN_MSK;
+ setup->afe |= FIELD_PREP(AD4170_AFE_PGA_GAIN_MSK, pga);
+
+ ret = ad4170_write_channel_setup(st, chan->address, false);
+ if (ret) {
+ setup->afe &= ~AD4170_AFE_PGA_GAIN_MSK;
+ setup->afe |= FIELD_PREP(AD4170_AFE_PGA_GAIN_MSK, old_pga);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __ad4170_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ return ad4170_set_pga(st, chan, val, val2);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4170_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long info)
+{
+ int ret;
+
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ ret = __ad4170_write_raw(indio_dev, chan, val, val2, info);
+ iio_device_release_direct(indio_dev);
+ return ret;
+}
+
+static int ad4170_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ad4170_info = {
+ .read_raw = ad4170_read_raw,
+ .read_avail = ad4170_read_avail,
+ .write_raw = ad4170_write_raw,
+ .write_raw_get_fmt = ad4170_write_raw_get_fmt,
+ .debugfs_reg_access = ad4170_debugfs_reg_access,
+};
+
+static int ad4170_soft_reset(struct ad4170_state *st)
+{
+ int ret;
+
+ ret = regmap_write(st->regmap, AD4170_CONFIG_A_REG,
+ AD4170_SW_RESET_MSK);
+ if (ret)
+ return ret;
+
+ /* AD4170-4 requires 1 ms between reset and any register access. */
+ fsleep(MILLI);
+
+ return 0;
+}
+
+static int ad4170_parse_reference(struct ad4170_state *st,
+ struct fwnode_handle *child,
+ struct ad4170_setup *setup)
+{
+ struct device *dev = &st->spi->dev;
+ int ret;
+ u8 aux;
+
+ /* Optional positive reference buffering, if omitted we use the default */
+ aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
+ ret = fwnode_property_read_u8(child, "adi,buffered-positive", &aux);
+ if (!ret) {
+ if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid adi,buffered-positive: %u\n",
+ aux);
+ }
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_P_MSK, aux);
+
+ /* Optional negative reference buffering, if omitted we use the default */
+ aux = AD4170_REF_BUF_FULL; /* Default to full precharge buffer enabled. */
+ ret = fwnode_property_read_u8(child, "adi,buffered-negative", &aux);
+ if (!ret) {
+ if (aux < AD4170_REF_BUF_PRE || aux > AD4170_REF_BUF_BYPASS)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid adi,buffered-negative: %u\n",
+ aux);
+ }
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_BUF_M_MSK, aux);
+
+ /* Optional voltage reference selection, if omitted we use the default */
+ aux = AD4170_REF_REFOUT; /* Default reference selection. */
+ ret = fwnode_property_read_u8(child, "adi,reference-select", &aux);
+ if (!ret) {
+ if (aux > AD4170_REF_AVDD)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid reference selected %u\n",
+ aux);
+ }
+ setup->afe |= FIELD_PREP(AD4170_AFE_REF_SELECT_MSK, aux);
+
+ return 0;
+}
+
+static int ad4170_parse_adc_channel_type(struct device *dev,
+ struct fwnode_handle *child,
+ struct iio_chan_spec *chan)
+{
+ u32 pins[2];
+ int ret, ret2;
+
+ /* Parse pseudo-differential channel configuration */
+ ret = fwnode_property_read_u32(child, "single-channel", &pins[0]);
+ ret2 = fwnode_property_read_u32(child, "common-mode-channel", &pins[1]);
+ if (!ret && ret2)
+ return dev_err_probe(dev, ret,
+ "single-ended channels must define common-mode-channel\n");
+ if (!ret) {
+ chan->differential = false;
+ chan->channel = pins[0];
+ chan->channel2 = pins[1];
+ return 0;
+ }
+
+ /* Parse differential channel configuration */
+ ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
+ ARRAY_SIZE(pins));
+ if (!ret) {
+ chan->differential = true;
+ chan->channel = pins[0];
+ chan->channel2 = pins[1];
+ return 0;
+ }
+ return dev_err_probe(dev, ret,
+ "Channel must define one of diff-channels or single-channel.\n");
+}
+
+static int ad4170_parse_channel_node(struct iio_dev *indio_dev,
+ struct fwnode_handle *child,
+ unsigned int chan_num)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ struct ad4170_chan_info *chan_info;
+ struct ad4170_setup *setup;
+ struct iio_chan_spec *chan;
+ unsigned int ch_reg;
+ u8 ref_select;
+ bool bipolar;
+ int ret;
+
+ ret = fwnode_property_read_u32(child, "reg", &ch_reg);
+ if (ret)
+ return dev_err_probe(dev, -EINVAL,
+ "Failed to read channel reg\n");
+
+ if (ch_reg >= AD4170_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL,
+ "Channel idx greater than no of channels\n");
+
+ chan = &st->chans[chan_num];
+ *chan = ad4170_channel_template;
+
+ chan->address = ch_reg;
+ chan->scan_index = ch_reg;
+ chan_info = &st->chan_infos[chan->address];
+
+ chan_info->setup_num = AD4170_INVALID_SETUP;
+ chan_info->initialized = true;
+
+ setup = &chan_info->setup;
+ ret = ad4170_parse_reference(st, child, setup);
+ if (ret)
+ return ret;
+
+ ret = ad4170_parse_adc_channel_type(dev, child, chan);
+ if (ret < 0)
+ return ret;
+
+ bipolar = fwnode_property_read_bool(child, "bipolar");
+ setup->afe |= FIELD_PREP(AD4170_AFE_BIPOLAR_MSK, bipolar);
+ if (bipolar)
+ chan->scan_type.sign = 's';
+ else
+ chan->scan_type.sign = 'u';
+
+ ref_select = FIELD_GET(AD4170_AFE_REF_SELECT_MSK, setup->afe);
+ ret = ad4170_validate_channel(st, chan);
+ if (ret < 0)
+ return ret;
+
+ ret = ad4170_get_input_range(st, chan, ch_reg, ref_select);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Invalid input config\n");
+
+ chan_info->input_range_uv = ret;
+ return 0;
+}
+
+static int ad4170_parse_channels(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ unsigned int num_channels;
+ unsigned int chan_num = 0;
+ int ret;
+
+ num_channels = device_get_child_node_count(dev);
+
+ if (num_channels > AD4170_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL, "Too many channels\n");
+
+ device_for_each_child_node_scoped(dev, child) {
+ ret = ad4170_parse_channel_node(indio_dev, child, chan_num++);
+ if (ret)
+ return ret;
+ }
+
+ indio_dev->num_channels = num_channels;
+ indio_dev->channels = st->chans;
+ return 0;
+}
+
+static int ad4170_parse_firmware(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ int reg_data, ret;
+ unsigned int i;
+
+ st->mclk_hz = AD4170_INT_CLOCK_16MHZ;
+
+ for (i = 0; i < AD4170_NUM_ANALOG_PINS; i++)
+ st->pins_fn[i] = AD4170_PIN_UNASIGNED;
+
+ /* On power on, device defaults to using SDO pin for data ready signal */
+ st->int_pin_sel = AD4170_INT_PIN_SDO;
+ ret = device_property_match_property_string(dev, "interrupt-names",
+ ad4170_int_pin_names,
+ ARRAY_SIZE(ad4170_int_pin_names));
+ if (ret >= 0)
+ st->int_pin_sel = ret;
+
+ reg_data = FIELD_PREP(AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK,
+ st->int_pin_sel == AD4170_INT_PIN_DIG_AUX1 ?
+ AD4170_PIN_MUXING_DIG_AUX1_RDY :
+ AD4170_PIN_MUXING_DIG_AUX1_DISABLED);
+
+ ret = regmap_update_bits(st->regmap, AD4170_PIN_MUXING_REG,
+ AD4170_PIN_MUXING_DIG_AUX1_CTRL_MSK, reg_data);
+ if (ret)
+ return ret;
+
+ return ad4170_parse_channels(indio_dev);
+}
+
+static int ad4170_initial_config(struct iio_dev *indio_dev)
+{
+ struct ad4170_state *st = iio_priv(indio_dev);
+ struct device *dev = &st->spi->dev;
+ unsigned int i;
+ int ret;
+
+ ret = ad4170_set_mode(st, AD4170_ADC_CTRL_MODE_IDLE);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to set ADC mode to idle\n");
+
+ for (i = 0; i < indio_dev->num_channels; i++) {
+ struct ad4170_chan_info *chan_info;
+ struct iio_chan_spec const *chan;
+ struct ad4170_setup *setup;
+ unsigned int val;
+
+ chan = &indio_dev->channels[i];
+ chan_info = &st->chan_infos[chan->address];
+
+ setup = &chan_info->setup;
+ setup->gain = AD4170_GAIN_REG_DEFAULT;
+ ret = ad4170_write_channel_setup(st, chan->address, false);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to write channel setup\n");
+
+ val = FIELD_PREP(AD4170_CHAN_MAP_AINP_MSK, chan->channel) |
+ FIELD_PREP(AD4170_CHAN_MAP_AINM_MSK, chan->channel2);
+
+ ret = regmap_write(st->regmap, AD4170_CHAN_MAP_REG(i), val);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to write CHAN_MAP_REG\n");
+
+ ret = ad4170_fill_scale_tbl(indio_dev, chan);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to fill scale tbl\n");
+ }
+
+ /* Disable all channels to avoid reading from unexpected channel */
+ ret = regmap_write(st->regmap, AD4170_CHAN_EN_REG, 0);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to disable channels\n");
+
+ /*
+ * Configure channels to share the same data output register, i.e. data
+ * can be read from the same register address regardless of channel
+ * number.
+ */
+ return regmap_update_bits(st->regmap, AD4170_ADC_CTRL_REG,
+ AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK,
+ AD4170_ADC_CTRL_MULTI_DATA_REG_SEL_MSK);
+}
+
+static irqreturn_t ad4170_irq_handler(int irq, void *dev_id)
+{
+ struct iio_dev *indio_dev = dev_id;
+ struct ad4170_state *st = iio_priv(indio_dev);
+
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+};
+
+static int ad4170_regulator_setup(struct ad4170_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ int ret;
+
+ /* Required regulators */
+ ret = devm_regulator_get_enable_read_voltage(dev, "avdd");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get AVDD voltage.\n");
+
+ st->vrefs_uv[AD4170_AVDD_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "iovdd");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get IOVDD voltage.\n");
+
+ st->vrefs_uv[AD4170_IOVDD_SUP] = ret;
+
+ /* Optional regulators */
+ ret = devm_regulator_get_enable_read_voltage(dev, "avss");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get AVSS voltage.\n");
+
+ /* Assume AVSS at GND (0V) if not provided */
+ st->vrefs_uv[AD4170_AVSS_SUP] = ret == -ENODEV ? 0 : -ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin1p");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN+ voltage.\n");
+
+ st->vrefs_uv[AD4170_REFIN1P_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin1n");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN- voltage.\n");
+
+ /* Negative supplies are assumed to provide negative voltage */
+ st->vrefs_uv[AD4170_REFIN1N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin2p");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN2+ voltage.\n");
+
+ st->vrefs_uv[AD4170_REFIN2P_SUP] = ret;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "refin2n");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(dev, ret, "Failed to get REFIN2- voltage.\n");
+
+ /* Negative supplies are assumed to provide negative voltage */
+ st->vrefs_uv[AD4170_REFIN2N_SUP] = ret == -ENODEV ? -ENODEV : -ret;
+
+ return 0;
+}
+
+static int ad4170_probe(struct spi_device *spi)
+{
+ const struct ad4170_chip_info *chip;
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ad4170_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ ret = devm_mutex_init(dev, &st->lock);
+ if (ret)
+ return ret;
+
+ chip = spi_get_device_match_data(spi);
+ if (!chip)
+ return -EINVAL;
+
+ indio_dev->name = chip->name;
+ indio_dev->info = &ad4170_info;
+
+ st->spi = spi;
+
+ st->regmap = devm_regmap_init(dev, NULL, st, &ad4170_regmap_config);
+ if (IS_ERR(st->regmap))
+ return dev_err_probe(dev, PTR_ERR(st->regmap),
+ "Failed to initialize regmap\n");
+
+ ret = ad4170_regulator_setup(st);
+ if (ret)
+ return ret;
+
+ ret = ad4170_soft_reset(st);
+ if (ret)
+ return ret;
+
+ ret = ad4170_parse_firmware(indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to parse firmware\n");
+
+ ret = ad4170_initial_config(indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to setup device\n");
+
+ init_completion(&st->completion);
+
+ if (spi->irq) {
+ ret = devm_request_irq(&st->spi->dev, st->spi->irq,
+ &ad4170_irq_handler, IRQF_ONESHOT,
+ indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ad4170_id_table[] = {
+ { "ad4170", (kernel_ulong_t)&ad4170_chip_info },
+ { "ad4190", (kernel_ulong_t)&ad4190_chip_info },
+ { "ad4195", (kernel_ulong_t)&ad4195_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad4170_id_table);
+
+static const struct of_device_id ad4170_of_match[] = {
+ { .compatible = "adi,ad4170", .data = &ad4170_chip_info },
+ { .compatible = "adi,ad4190", .data = &ad4190_chip_info },
+ { .compatible = "adi,ad4195", .data = &ad4195_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad4170_of_match);
+
+static struct spi_driver ad4170_driver = {
+ .driver = {
+ .name = "ad4170",
+ .of_match_table = ad4170_of_match,
+ },
+ .probe = ad4170_probe,
+ .id_table = ad4170_id_table,
+};
+module_spi_driver(ad4170_driver);
+
+MODULE_AUTHOR("Ana-Maria Cusco <ana-maria.cusco@analog.com>");
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD4170 SPI driver");
+MODULE_LICENSE("GPL");