[PATCH v8 1/3] iio: adc: add max11410 adc driver

From: Ibrahim Tilki
Date: Mon Oct 03 2022 - 06:59:49 EST

Adding support for max11410 24-bit, 1.9ksps delta-sigma adc which
has 3 differential reference and 10 differential channel inputs.
Inputs and references can be buffered internally. Inputs can also
be amplified with internal PGA.

Device has four digital filter modes: FIR50/60, FIR50, FIR60 and SINC4.
FIR 50Hz and 60Hz rejections can be enabled/disabled separately.
Digital filter selection affects sampling frequency range so driver
has to consider the configured filter when configuring sampling frequency.

Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/max11410.c | 1050 ++++++++++++++++++++++++++++++++++++
3 files changed, 1064 insertions(+)
create mode 100644 drivers/iio/adc/max11410.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 791612ca60..544986fd45 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -667,6 +667,19 @@ config MAX11205
To compile this driver as a module, choose M here: the module will be
called max11205.

+config MAX11410
+ tristate "Analog Devices MAX11410 ADC driver"
+ depends on SPI
+ select REGMAP_SPI
+ select IIO_BUFFER
+ select IIO_TRIGGER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for Analog Devices MAX11410 ADCs.
+
+ To compile this driver as a module, choose M here: the module will be
+ called max11410.
+
config MAX1241
tristate "Maxim max1241 ADC driver"
depends on SPI_MASTER
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 46caba7a01..4d80341342 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX11100) += max11100.o
obj-$(CONFIG_MAX1118) += max1118.o
obj-$(CONFIG_MAX11205) += max11205.o
+obj-$(CONFIG_MAX11410) += max11410.o
obj-$(CONFIG_MAX1241) += max1241.o
obj-$(CONFIG_MAX1363) += max1363.o
obj-$(CONFIG_MAX9611) += max9611.o
diff --git a/drivers/iio/adc/max11410.c b/drivers/iio/adc/max11410.c
new file mode 100644
index 0000000000..aa25e78655
--- /dev/null
+++ b/drivers/iio/adc/max11410.c
@@ -0,0 +1,1050 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MAX11410 SPI ADC driver
+ *
+ * Copyright 2022 Analog Devices Inc.
+ */
+#include <asm-generic/unaligned.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MAX11410_REG_CONV_START 0x01
+#define MAX11410_CONV_TYPE_SINGLE 0x00
+#define MAX11410_CONV_TYPE_CONTINUOUS 0x01
+#define MAX11410_REG_CAL_START 0x03
+#define MAX11410_CAL_START_SELF 0x00
+#define MAX11410_CAL_START_PGA 0x01
+#define MAX11410_REG_GPIO_CTRL(ch) ((ch) ? 0x05 : 0x04)
+#define MAX11410_GPIO_INTRB 0xC1
+#define MAX11410_REG_FILTER 0x08
+#define MAX11410_FILTER_RATE_MASK GENMASK(3, 0)
+#define MAX11410_FILTER_RATE_MAX 0x0F
+#define MAX11410_FILTER_LINEF_MASK GENMASK(5, 4)
+#define MAX11410_FILTER_50HZ BIT(5)
+#define MAX11410_FILTER_60HZ BIT(4)
+#define MAX11410_REG_CTRL 0x09
+#define MAX11410_CTRL_REFSEL_MASK GENMASK(2, 0)
+#define MAX11410_CTRL_VREFN_BUF_BIT BIT(3)
+#define MAX11410_CTRL_VREFP_BUF_BIT BIT(4)
+#define MAX11410_CTRL_FORMAT_BIT BIT(5)
+#define MAX11410_CTRL_UNIPOLAR_BIT BIT(6)
+#define MAX11410_REG_MUX_CTRL0 0x0B
+#define MAX11410_REG_PGA 0x0E
+#define MAX11410_PGA_GAIN_MASK GENMASK(2, 0)
+#define MAX11410_PGA_SIG_PATH_MASK GENMASK(5, 4)
+#define MAX11410_PGA_SIG_PATH_BUFFERED 0x00
+#define MAX11410_PGA_SIG_PATH_BYPASS 0x01
+#define MAX11410_PGA_SIG_PATH_PGA 0x02
+#define MAX11410_REG_DATA0 0x30
+#define MAX11410_REG_STATUS 0x38
+#define MAX11410_STATUS_CONV_READY_BIT BIT(0)
+#define MAX11410_STATUS_CAL_READY_BIT BIT(2)
+
+#define MAX11410_REFSEL_AVDD_AGND 0x03
+#define MAX11410_REFSEL_MAX 0x06
+#define MAX11410_SIG_PATH_MAX 0x02
+#define MAX11410_CHANNEL_INDEX_MAX 0x0A
+#define MAX11410_AINP_AVDD 0x0A
+#define MAX11410_AINN_GND 0x0A
+
+#define MAX11410_CONVERSION_TIMEOUT_MS 2000
+#define MAX11410_CALIB_TIMEOUT_MS 2000
+
+#define MAX11410_SCALE_AVAIL_SIZE 8
+
+enum max11410_filter {
+ MAX11410_FILTER_FIR5060,
+ MAX11410_FILTER_FIR50,
+ MAX11410_FILTER_FIR60,
+ MAX11410_FILTER_SINC4,
+};
+
+static const u8 max11410_sampling_len[] = {
+ [MAX11410_FILTER_FIR5060] = 5,
+ [MAX11410_FILTER_FIR50] = 6,
+ [MAX11410_FILTER_FIR60] = 6,
+ [MAX11410_FILTER_SINC4] = 10,
+};
+
+static const int max11410_sampling_rates[4][10][2] = {
+ [MAX11410_FILTER_FIR5060] = {
+ { 1, 100000 },
+ { 2, 100000 },
+ { 4, 200000 },
+ { 8, 400000 },
+ { 16, 800000 }
+ },
+ [MAX11410_FILTER_FIR50] = {
+ { 1, 300000 },
+ { 2, 700000 },
+ { 5, 300000 },
+ { 10, 700000 },
+ { 21, 300000 },
+ { 40 }
+ },
+ [MAX11410_FILTER_FIR60] = {
+ { 1, 300000 },
+ { 2, 700000 },
+ { 5, 300000 },
+ { 10, 700000 },
+ { 21, 300000 },
+ { 40 }
+ },
+ [MAX11410_FILTER_SINC4] = {
+ { 4 },
+ { 10 },
+ { 20 },
+ { 40 },
+ { 60 },
+ { 120 },
+ { 240 },
+ { 480 },
+ { 960 },
+ { 1920 }
+ }
+};
+
+struct max11410_channel_config {
+ u32 settling_time_us;
+ u32 *scale_avail;
+ u8 refsel;
+ u8 sig_path;
+ u8 gain;
+ bool bipolar;
+ bool buffered_vrefp;
+ bool buffered_vrefn;
+};
+
+struct max11410_state {
+ struct spi_device *spi_dev;
+ struct iio_trigger *trig;
+ struct completion completion;
+ struct mutex lock; /* Prevent changing channel config during sampling */
+ struct regmap *regmap;
+ struct regulator *avdd;
+ struct regulator *vrefp[3];
+ struct regulator *vrefn[3];
+ struct max11410_channel_config *channels;
+ int irq;
+ struct {
+ u32 data __aligned(IIO_DMA_MINALIGN);
+ s64 ts __aligned(8);
+ } scan;
+};
+
+static const struct iio_chan_spec chanspec_template = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .scan_type = {
+ .sign = 's',
+ .realbits = 24,
+ .storagebits = 32,
+ .endianness = IIO_LE,
+ },
+};
+
+static unsigned int max11410_reg_size(unsigned int reg)
+{
+ /* Registers from 0x00 to 0x10 are 1 byte, the rest are 3 bytes long. */
+ return reg <= 0x10 ? 1 : 3;
+}
+
+static int max11410_write_reg(struct max11410_state *st, unsigned int reg,
+ unsigned int val)
+{
+ /* This driver only needs to write 8-bit registers */
+ if (max11410_reg_size(reg) != 1)
+ return -EINVAL;
+
+ return regmap_write(st->regmap, reg, val);
+}
+
+static int max11410_read_reg(struct max11410_state *st, unsigned int reg,
+ int *val)
+{
+ int ret;
+
+ if (max11410_reg_size(reg) == 3) {
+ ret = regmap_bulk_read(st->regmap, reg, &st->scan.data, 3);
+ if (ret)
+ return ret;
+
+ *val = get_unaligned_be24(&st->scan.data);
+ return 0;
+ }
+
+ return regmap_read(st->regmap, reg, val);
+}
+
+static struct regulator *max11410_get_vrefp(struct max11410_state *st,
+ u8 refsel)
+{
+ refsel = refsel % 4;
+ if (refsel == 3)
+ return st->avdd;
+
+ return st->vrefp[refsel];
+}
+
+static struct regulator *max11410_get_vrefn(struct max11410_state *st,
+ u8 refsel)
+{
+ if (refsel > 2)
+ return NULL;
+
+ return st->vrefn[refsel];
+}
+
+static const struct regmap_config regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x39,
+};
+
+static ssize_t max11410_notch_en_show(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct max11410_state *state = iio_priv(indio_dev);
+ struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
+ unsigned int val;
+ int ret;
+
+ ret = max11410_read_reg(state, MAX11410_REG_FILTER, &val);
+ if (ret)
+ return ret;
+
+ switch (iio_attr->address) {
+ case 0:
+ val = !FIELD_GET(MAX11410_FILTER_50HZ, val);
+ break;
+ case 1:
+ val = !FIELD_GET(MAX11410_FILTER_60HZ, val);
+ break;
+ case 2:
+ val = FIELD_GET(MAX11410_FILTER_LINEF_MASK, val) == 3;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t max11410_notch_en_store(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct max11410_state *state = iio_priv(indio_dev);
+ unsigned int filter_bits;
+ bool enable;
+ int ret;
+
+ ret = kstrtobool(buf, &enable);
+ if (ret)
+ return ret;
+
+ switch (iio_attr->address) {
+ case 0:
+ filter_bits = MAX11410_FILTER_50HZ;
+ break;
+ case 1:
+ filter_bits = MAX11410_FILTER_60HZ;
+ break;
+ case 2:
+ default:
+ filter_bits = MAX11410_FILTER_50HZ | MAX11410_FILTER_60HZ;
+ enable = !enable;
+ break;
+ }
+
+ if (enable)
+ ret = regmap_clear_bits(state->regmap, MAX11410_REG_FILTER,
+ filter_bits);
+ else
+ ret = regmap_set_bits(state->regmap, MAX11410_REG_FILTER,
+ filter_bits);
+
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static ssize_t in_voltage_filter2_notch_center_show(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct max11410_state *state = iio_priv(indio_dev);
+ int ret, reg, rate, filter;
+
+ ret = regmap_read(state->regmap, MAX11410_REG_FILTER, &reg);
+ if (ret)
+ return ret;
+
+ rate = FIELD_GET(MAX11410_FILTER_RATE_MASK, reg);
+ rate = clamp_val(rate, 0,
+ max11410_sampling_len[MAX11410_FILTER_SINC4] - 1);
+ filter = max11410_sampling_rates[MAX11410_FILTER_SINC4][rate][0];
+
+ return sysfs_emit(buf, "%d\n", filter);
+}
+
+static IIO_CONST_ATTR(in_voltage_filter0_notch_center, "50");
+static IIO_CONST_ATTR(in_voltage_filter1_notch_center, "60");
+static IIO_DEVICE_ATTR_RO(in_voltage_filter2_notch_center, 2);
+
+static IIO_DEVICE_ATTR(in_voltage_filter0_notch_en, 0644,
+ max11410_notch_en_show, max11410_notch_en_store, 0);
+static IIO_DEVICE_ATTR(in_voltage_filter1_notch_en, 0644,
+ max11410_notch_en_show, max11410_notch_en_store, 1);
+static IIO_DEVICE_ATTR(in_voltage_filter2_notch_en, 0644,
+ max11410_notch_en_show, max11410_notch_en_store, 2);
+
+static struct attribute *max11410_attributes[] = {
+ &iio_const_attr_in_voltage_filter0_notch_center.dev_attr.attr,
+ &iio_const_attr_in_voltage_filter1_notch_center.dev_attr.attr,
+ &iio_dev_attr_in_voltage_filter2_notch_center.dev_attr.attr,
+ &iio_dev_attr_in_voltage_filter0_notch_en.dev_attr.attr,
+ &iio_dev_attr_in_voltage_filter1_notch_en.dev_attr.attr,
+ &iio_dev_attr_in_voltage_filter2_notch_en.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group max11410_attribute_group = {
+ .attrs = max11410_attributes,
+};
+
+static int max11410_set_input_mux(struct max11410_state *st, u8 ainp, u8 ainn)
+{
+ if (ainp > MAX11410_CHANNEL_INDEX_MAX ||
+ ainn > MAX11410_CHANNEL_INDEX_MAX)
+ return -EINVAL;
+
+ return max11410_write_reg(st, MAX11410_REG_MUX_CTRL0,
+ (ainp << 4) | ainn);
+}
+
+static int max11410_configure_channel(struct max11410_state *st,
+ struct iio_chan_spec const *chan)
+{
+ struct max11410_channel_config cfg = st->channels[chan->address];
+ unsigned int regval;
+ int ret;
+
+ if (chan->differential)
+ ret = max11410_set_input_mux(st, chan->channel, chan->channel2);
+ else
+ ret = max11410_set_input_mux(st, chan->channel,
+ MAX11410_AINN_GND);
+
+ if (ret)
+ return ret;
+
+ regval = FIELD_PREP(MAX11410_CTRL_VREFP_BUF_BIT, cfg.buffered_vrefp) |
+ FIELD_PREP(MAX11410_CTRL_VREFN_BUF_BIT, cfg.buffered_vrefn) |
+ FIELD_PREP(MAX11410_CTRL_REFSEL_MASK, cfg.refsel) |
+ FIELD_PREP(MAX11410_CTRL_UNIPOLAR_BIT, !cfg.bipolar);
+ ret = regmap_update_bits(st->regmap, MAX11410_REG_CTRL,
+ MAX11410_CTRL_REFSEL_MASK |
+ MAX11410_CTRL_VREFN_BUF_BIT |
+ MAX11410_CTRL_VREFN_BUF_BIT |
+ MAX11410_CTRL_UNIPOLAR_BIT, regval);
+ if (ret)
+ return ret;
+
+ regval = FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK, cfg.sig_path) |
+ FIELD_PREP(MAX11410_PGA_GAIN_MASK, cfg.gain);
+ ret = regmap_write(st->regmap, MAX11410_REG_PGA, regval);
+ if (ret)
+ return ret;
+
+ if (cfg.settling_time_us)
+ fsleep(cfg.settling_time_us);
+
+ return 0;
+}
+
+static int max11410_sample(struct max11410_state *st, int *sample_raw,
+ struct iio_chan_spec const *chan)
+{
+ int val, ret;
+
+ ret = max11410_configure_channel(st, chan);
+ if (ret)
+ return ret;
+
+ if (st->irq > 0)
+ reinit_completion(&st->completion);
+
+ /* Start Conversion */
+ ret = max11410_write_reg(st, MAX11410_REG_CONV_START,
+ MAX11410_CONV_TYPE_SINGLE);
+ if (ret)
+ return ret;
+
+ if (st->irq > 0) {
+ /* Wait for an interrupt. */
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(MAX11410_CONVERSION_TIMEOUT_MS));
+ if (!ret)
+ return -ETIMEDOUT;
+ } else {
+ /* Wait for status register Conversion Ready flag */
+ ret = read_poll_timeout(max11410_read_reg, ret,
+ ret || (val & MAX11410_STATUS_CONV_READY_BIT),
+ 5000, MAX11410_CONVERSION_TIMEOUT_MS * 1000,
+ true, st, MAX11410_REG_STATUS, &val);
+ if (ret)
+ return ret;
+ }
+
+ /* Read ADC Data */
+ return max11410_read_reg(st, MAX11410_REG_DATA0, sample_raw);
+}
+
+static int max11410_get_scale(struct max11410_state *state,
+ struct max11410_channel_config cfg)
+{
+ struct regulator *vrefp, *vrefn;
+ int scale;
+
+ vrefp = max11410_get_vrefp(state, cfg.refsel);
+
+ scale = regulator_get_voltage(vrefp) / 1000;
+ vrefn = max11410_get_vrefn(state, cfg.refsel);
+ if (vrefn)
+ scale -= regulator_get_voltage(vrefn) / 1000;
+
+ if (cfg.bipolar)
+ scale *= 2;
+
+ return scale >> cfg.gain;
+}
+
+static int max11410_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long info)
+{
+ struct max11410_state *state = iio_priv(indio_dev);
+ struct max11410_channel_config cfg = state->channels[chan->address];
+ int ret, reg_val, filter, rate;
+
+ switch (info) {
+ case IIO_CHAN_INFO_SCALE:
+ *val = max11410_get_scale(state, cfg);
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_OFFSET:
+ if (cfg.bipolar)
+ *val = -BIT(chan->scan_type.realbits - 1);
+ else
+ *val = 0;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ mutex_lock(&state->lock);
+
+ ret = max11410_sample(state, &reg_val, chan);
+
+ mutex_unlock(&state->lock);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ if (ret)
+ return ret;
+
+ *val = reg_val;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = regmap_read(state->regmap, MAX11410_REG_FILTER, &reg_val);
+ if (ret)
+ return ret;
+
+ filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+ rate = reg_val & MAX11410_FILTER_RATE_MASK;
+ if (rate >= max11410_sampling_len[filter])
+ rate = max11410_sampling_len[filter] - 1;
+
+ *val = max11410_sampling_rates[filter][rate][0];
+ *val2 = max11410_sampling_rates[filter][rate][1];
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ return -EINVAL;
+}
+
+static int max11410_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct max11410_state *st = iio_priv(indio_dev);
+ int i, ret, reg_val, filter, gain;
+ u32 *scale_avail;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ scale_avail = st->channels[chan->address].scale_avail;
+ if (!scale_avail)
+ return -EOPNOTSUPP;
+
+ /* Accept values in range 0.000001 <= scale < 1.000000 */
+ if (val != 0 || val2 == 0)
+ return -EINVAL;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ /* Convert from INT_PLUS_MICRO to FRACTIONAL_LOG2 */
+ val2 = val2 * DIV_ROUND_CLOSEST(BIT(24), 1000000);
+ val2 = DIV_ROUND_CLOSEST(scale_avail[0], val2);
+ gain = order_base_2(val2);
+
+ st->channels[chan->address].gain = clamp_val(gain, 0, 7);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ return 0;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ mutex_lock(&st->lock);
+
+ ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
+ if (ret)
+ goto out;
+
+ filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+
+ for (i = 0; i < max11410_sampling_len[filter]; ++i) {
+ if (val == max11410_sampling_rates[filter][i][0] &&
+ val2 == max11410_sampling_rates[filter][i][1])
+ break;
+ }
+ if (i == max11410_sampling_len[filter]) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+ MAX11410_FILTER_RATE_MASK, i);
+
+out:
+ mutex_unlock(&st->lock);
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int max11410_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ struct max11410_state *st = iio_priv(indio_dev);
+ struct max11410_channel_config cfg;
+ int ret, reg_val, filter;
+
+ switch (info) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
+ if (ret)
+ return ret;
+
+ filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
+
+ *vals = (const int *)max11410_sampling_rates[filter];
+ *length = max11410_sampling_len[filter] * 2;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SCALE:
+ cfg = st->channels[chan->address];
+
+ if (!cfg.scale_avail)
+ return -EINVAL;
+
+ *vals = cfg.scale_avail;
+ *length = MAX11410_SCALE_AVAIL_SIZE * 2;
+ *type = IIO_VAL_FRACTIONAL_LOG2;
+
+ return IIO_AVAIL_LIST;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_info max11410_info = {
+ .read_raw = max11410_read_raw,
+ .write_raw = max11410_write_raw,
+ .read_avail = max11410_read_avail,
+ .attrs = &max11410_attribute_group,
+};
+
+static irqreturn_t max11410_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct max11410_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = max11410_read_reg(st, MAX11410_REG_DATA0, &st->scan.data);
+ if (ret) {
+ dev_err(&indio_dev->dev, "cannot read data\n");
+ goto out;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
+ iio_get_time_ns(indio_dev));
+
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int max11410_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct max11410_state *st = iio_priv(indio_dev);
+ int scan_ch, ret;
+
+ scan_ch = ffs(*indio_dev->active_scan_mask) - 1;
+
+ ret = max11410_configure_channel(st, &indio_dev->channels[scan_ch]);
+ if (ret)
+ return ret;
+
+ /* Start continuous conversion. */
+ return max11410_write_reg(st, MAX11410_REG_CONV_START,
+ MAX11410_CONV_TYPE_CONTINUOUS);
+}
+
+static int max11410_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct max11410_state *st = iio_priv(indio_dev);
+
+ /* Stop continuous conversion. */
+ return max11410_write_reg(st, MAX11410_REG_CONV_START,
+ MAX11410_CONV_TYPE_SINGLE);
+}
+
+static const struct iio_buffer_setup_ops max11410_buffer_ops = {
+ .postenable = &max11410_buffer_postenable,
+ .predisable = &max11410_buffer_predisable,
+ .validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
+static const struct iio_trigger_ops max11410_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static irqreturn_t max11410_interrupt(int irq, void *dev_id)
+{
+ struct iio_dev *indio_dev = dev_id;
+ struct max11410_state *st = iio_priv(indio_dev);
+
+ if (iio_buffer_enabled(indio_dev))
+ iio_trigger_poll_chained(st->trig);
+ else
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+};
+
+static int max11410_parse_channels(struct max11410_state *st,
+ struct iio_dev *indio_dev)
+{
+ struct iio_chan_spec chanspec = chanspec_template;
+ struct device *dev = &st->spi_dev->dev;
+ struct max11410_channel_config *cfg;
+ struct iio_chan_spec *channels;
+ struct fwnode_handle *child;
+ u32 reference, sig_path;
+ const char *node_name;
+ u32 inputs[2], scale;
+ unsigned int num_ch;
+ int chan_idx = 0;
+ int ret, i;
+
+ num_ch = device_get_child_node_count(dev);
+ if (num_ch == 0)
+ return dev_err_probe(&indio_dev->dev, -ENODEV,
+ "FW has no channels defined\n");
+
+ /* Reserve space for soft timestamp channel */
+ num_ch++;
+ channels = devm_kcalloc(dev, num_ch, sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ st->channels = devm_kcalloc(dev, num_ch, sizeof(*st->channels),
+ GFP_KERNEL);
+ if (!st->channels)
+ return -ENOMEM;
+
+ device_for_each_child_node(dev, child) {
+ node_name = fwnode_get_name(child);
+ if (fwnode_property_present(child, "diff-channels")) {
+ ret = fwnode_property_read_u32_array(child,
+ "diff-channels",
+ inputs,
+ ARRAY_SIZE(inputs));
+
+ chanspec.differential = 1;
+ } else {
+ ret = fwnode_property_read_u32(child, "reg", &inputs[0]);
+
+ inputs[1] = 0;
+ chanspec.differential = 0;
+ }
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ if (inputs[0] > MAX11410_CHANNEL_INDEX_MAX ||
+ inputs[1] > MAX11410_CHANNEL_INDEX_MAX) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Invalid channel index for %s, should be less than %d\n",
+ node_name,
+ MAX11410_CHANNEL_INDEX_MAX + 1);
+ }
+
+ cfg = &st->channels[chan_idx];
+
+ reference = MAX11410_REFSEL_AVDD_AGND;
+ fwnode_property_read_u32(child, "adi,reference", &reference);
+ if (reference > MAX11410_REFSEL_MAX) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Invalid adi,reference value for %s, should be less than %d.\n",
+ node_name, MAX11410_REFSEL_MAX + 1);
+ }
+
+ if (!max11410_get_vrefp(st, reference) ||
+ (!max11410_get_vrefn(st, reference) && reference <= 2)) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Invalid VREF configuration for %s, either specify corresponding VREF regulators or change adi,reference property.\n",
+ node_name);
+ }
+
+ sig_path = MAX11410_PGA_SIG_PATH_BUFFERED;
+ fwnode_property_read_u32(child, "adi,input-mode", &sig_path);
+ if (sig_path > MAX11410_SIG_PATH_MAX) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Invalid adi,input-mode value for %s, should be less than %d.\n",
+ node_name, MAX11410_SIG_PATH_MAX + 1);
+ }
+
+ fwnode_property_read_u32(child, "settling-time-us",
+ &cfg->settling_time_us);
+ cfg->bipolar = fwnode_property_read_bool(child, "bipolar");
+ cfg->buffered_vrefp = fwnode_property_read_bool(child, "adi,buffered-vrefp");
+ cfg->buffered_vrefn = fwnode_property_read_bool(child, "adi,buffered-vrefn");
+ cfg->refsel = reference;
+ cfg->sig_path = sig_path;
+ cfg->gain = 0;
+
+ /* Enable scale_available property if input mode is PGA */
+ if (sig_path == MAX11410_PGA_SIG_PATH_PGA) {
+ __set_bit(IIO_CHAN_INFO_SCALE,
+ &chanspec.info_mask_separate_available);
+ cfg->scale_avail = devm_kcalloc(dev, MAX11410_SCALE_AVAIL_SIZE * 2,
+ sizeof(*cfg->scale_avail),
+ GFP_KERNEL);
+ if (!cfg->scale_avail) {
+ fwnode_handle_put(child);
+ return -ENOMEM;
+ }
+
+ scale = max11410_get_scale(st, *cfg);
+ for (i = 0; i < MAX11410_SCALE_AVAIL_SIZE; i++) {
+ cfg->scale_avail[2 * i] = scale >> i;
+ cfg->scale_avail[2 * i + 1] = chanspec.scan_type.realbits;
+ }
+ } else {
+ __clear_bit(IIO_CHAN_INFO_SCALE,
+ &chanspec.info_mask_separate_available);
+ }
+
+ chanspec.address = chan_idx;
+ chanspec.scan_index = chan_idx;
+ chanspec.channel = inputs[0];
+ chanspec.channel2 = inputs[1];
+
+ channels[chan_idx] = chanspec;
+ chan_idx++;
+ }
+
+ channels[chan_idx] = (struct iio_chan_spec)IIO_CHAN_SOFT_TIMESTAMP(chan_idx);
+
+ indio_dev->num_channels = chan_idx + 1;
+ indio_dev->channels = channels;
+
+ return 0;
+}
+
+static void max11410_disable_reg(void *reg)
+{
+ regulator_disable(reg);
+}
+
+static int max11410_init_vref(struct device *dev,
+ struct regulator **vref,
+ const char *id)
+{
+ struct regulator *reg;
+ int ret;
+
+ reg = devm_regulator_get_optional(dev, id);
+ if (PTR_ERR(reg) == -ENODEV) {
+ *vref = NULL;
+ return 0;
+ } else if (IS_ERR(reg)) {
+ return PTR_ERR(reg);
+ }
+ ret = regulator_enable(reg);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to enable regulator %s\n", id);
+
+ *vref = reg;
+ return devm_add_action_or_reset(dev, max11410_disable_reg, reg);
+}
+
+static int max11410_calibrate(struct max11410_state *st, u32 cal_type)
+{
+ int ret, val;
+
+ ret = max11410_write_reg(st, MAX11410_REG_CAL_START, cal_type);
+ if (ret)
+ return ret;
+
+ /* Wait for status register Calibration Ready flag */
+ return read_poll_timeout(max11410_read_reg, ret,
+ ret || (val & MAX11410_STATUS_CAL_READY_BIT),
+ 50000, MAX11410_CALIB_TIMEOUT_MS * 1000, true,
+ st, MAX11410_REG_STATUS, &val);
+}
+
+static int max11410_self_calibrate(struct max11410_state *st)
+{
+ int ret, i;
+
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+ MAX11410_FILTER_RATE_MASK,
+ FIELD_PREP(MAX11410_FILTER_RATE_MASK,
+ MAX11410_FILTER_RATE_MAX));
+ if (ret)
+ return ret;
+
+ ret = max11410_calibrate(st, MAX11410_CAL_START_SELF);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+ MAX11410_PGA_SIG_PATH_MASK,
+ FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
+ MAX11410_PGA_SIG_PATH_PGA));
+ if (ret)
+ return ret;
+
+ /* PGA calibrations */
+ for (i = 1; i < 8; ++i) {
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+ MAX11410_PGA_GAIN_MASK, i);
+ if (ret)
+ return ret;
+
+ ret = max11410_calibrate(st, MAX11410_CAL_START_PGA);
+ if (ret)
+ return ret;
+ }
+
+ /* Cleanup */
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+ MAX11410_PGA_GAIN_MASK, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
+ MAX11410_FILTER_RATE_MASK, 0);
+ if (ret)
+ return ret;
+
+ return regmap_write_bits(st->regmap, MAX11410_REG_PGA,
+ MAX11410_PGA_SIG_PATH_MASK,
+ FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
+ MAX11410_PGA_SIG_PATH_BUFFERED));
+}
+
+static int max11410_probe(struct spi_device *spi)
+{
+ const char *vrefp_regs[] = { "vref0p", "vref1p", "vref2p" };
+ const char *vrefn_regs[] = { "vref0n", "vref1n", "vref2n" };
+ struct device *dev = &spi->dev;
+ struct max11410_state *st;
+ struct iio_dev *indio_dev;
+ int ret, irqs[2];
+ int i;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi_dev = spi;
+ init_completion(&st->completion);
+ mutex_init(&st->lock);
+
+ indio_dev->name = "max11410";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &max11410_info;
+
+ st->regmap = devm_regmap_init_spi(spi, &regmap_config);
+ if (IS_ERR(st->regmap))
+ return dev_err_probe(dev, PTR_ERR(st->regmap),
+ "regmap initialization failed\n");
+
+ ret = max11410_init_vref(dev, &st->avdd, "avdd");
+ if (ret)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(vrefp_regs); i++) {
+ ret = max11410_init_vref(dev, &st->vrefp[i], vrefp_regs[i]);
+ if (ret)
+ return ret;
+
+ ret = max11410_init_vref(dev, &st->vrefn[i], vrefn_regs[i]);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Regulators must be configured before parsing channels for
+ * validating "adi,reference" property of each channel.
+ */
+ ret = max11410_parse_channels(st, indio_dev);
+ if (ret)
+ return ret;
+
+ irqs[0] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio0");
+ irqs[1] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio1");
+
+ if (irqs[0] > 0) {
+ st->irq = irqs[0];
+ ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(0),
+ MAX11410_GPIO_INTRB);
+ } else if (irqs[1] > 0) {
+ st->irq = irqs[1];
+ ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(1),
+ MAX11410_GPIO_INTRB);
+ } else if (spi->irq > 0) {
+ return dev_err_probe(dev, -ENODEV,
+ "no interrupt name specified");
+ }
+
+ if (ret)
+ return ret;
+
+ ret = regmap_set_bits(st->regmap, MAX11410_REG_CTRL,
+ MAX11410_CTRL_FORMAT_BIT);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+ &max11410_trigger_handler,
+ &max11410_buffer_ops);
+ if (ret)
+ return ret;
+
+ if (st->irq > 0) {
+ st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!st->trig)
+ return -ENOMEM;
+
+ st->trig->ops = &max11410_trigger_ops;
+ ret = devm_iio_trigger_register(dev, st->trig);
+ if (ret)
+ return ret;
+
+ ret = devm_request_threaded_irq(dev, st->irq, NULL,
+ &max11410_interrupt,
+ IRQF_ONESHOT, "max11410",
+ indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ ret = max11410_self_calibrate(st);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "cannot perform device self calibration\n");
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id max11410_spi_of_id[] = {
+ { .compatible = "adi,max11410" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max11410_spi_of_id);
+
+static const struct spi_device_id max11410_id[] = {
+ { "max11410" },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, max11410_id);
+
+static struct spi_driver max11410_driver = {
+ .driver = {
+ .name = "max11410",
+ .of_match_table = max11410_spi_of_id,
+ },
+ .probe = max11410_probe,
+ .id_table = max11410_id,
+};
+module_spi_driver(max11410_driver);
+
+MODULE_AUTHOR("David Jung <David.Jung@xxxxxxxxxx>");
+MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices MAX11410 ADC");
+MODULE_LICENSE("GPL");
--
2.25.1