[PATCH v3 6/6] iio: adc: ad4851: add ad485x driver

From: Antoniu Miclaus
Date: Mon Oct 14 2024 - 05:50:57 EST

Add support for the AD485X a fully buffered, 8-channel simultaneous
sampling, 16/20-bit, 1 MSPS data acquisition system (DAS) with
differential, wide common-mode range inputs.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
---
- rename ad485x occurences with ad4851
- list all supported parts in Kconfig
- drop product id macro definitions and use values inline.
- drop scale/offset from device state and encode them directly.
- use switch..case for realbits if..else statement.
- replace {} -> { }
- drop scale table from chip info and use it inline.
- use alphanumeric order for spi_id table and of_match table.
- improve commit description.
- use bitmap instead of bool matrix.
- use pow-of-2 alignment for scale_avail
- use MICRO/MEGA where missing.
- include bitfield.h
- increse lower limit of clamp() to 1.
- add error message for devm_pwm_get().
- implement oversampling ratio and adjust the packet_format based on it.
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad4851.c | 1113 ++++++++++++++++++++++++++++++++++++++
3 files changed, 1127 insertions(+)
create mode 100644 drivers/iio/adc/ad4851.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index f60fe85a30d5..93e53794ce89 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -36,6 +36,19 @@ config AD4130
To compile this driver as a module, choose M here: the module will be
called ad4130.

+config AD4851
+ tristate "Analog Device AD4851 DAS Driver"
+ depends on SPI
+ select REGMAP_SPI
+ select IIO_BACKEND
+ help
+ Say yes here to build support for Analog Devices AD4851, AD4852,
+ AD4853, AD4854, AD4855, AD4856, AD4857, AD4858, AD4858I high speed
+ data acquisition system (DAS).
+
+ To compile this driver as a module, choose M here: the module will be
+ called ad4851.
+
config AD7091R
tristate

diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d370e066544e..1a873bf1a917 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-$(CONFIG_AD4130) += ad4130.o
+obj-$(CONFIG_AD4851) += ad4851.o
obj-$(CONFIG_AD7091R) += ad7091r-base.o
obj-$(CONFIG_AD7091R5) += ad7091r5.o
obj-$(CONFIG_AD7091R8) += ad7091r8.o
diff --git a/drivers/iio/adc/ad4851.c b/drivers/iio/adc/ad4851.c
new file mode 100644
index 000000000000..99c9367de383
--- /dev/null
+++ b/drivers/iio/adc/ad4851.c
@@ -0,0 +1,1113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD4851 DAS driver
+ *
+ * Copyright 2024 Analog Devices Inc.
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/minmax.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include <linux/iio/backend.h>
+#include <linux/iio/iio.h>
+
+#include <asm/unaligned.h>
+
+#define AD4851_REG_INTERFACE_CONFIG_A 0x00
+#define AD4851_REG_INTERFACE_CONFIG_B 0x01
+#define AD4851_REG_PRODUCT_ID_L 0x04
+#define AD4851_REG_PRODUCT_ID_H 0x05
+#define AD4851_REG_DEVICE_CTRL 0x25
+#define AD4851_REG_PACKET 0x26
+#define AD4851_REG_OVERSAMPLE 0x27
+
+#define AD4851_REG_CH_CONFIG_BASE 0x2A
+#define AD4851_REG_CHX_SOFTSPAN(ch) ((0x12 * (ch)) + AD4851_REG_CH_CONFIG_BASE)
+#define AD4851_REG_CHX_OFFSET(ch) (AD4851_REG_CHX_SOFTSPAN(ch) + 0x01)
+#define AD4851_REG_CHX_OFFSET_LSB(ch) AD4851_REG_CHX_OFFSET(ch)
+#define AD4851_REG_CHX_OFFSET_MID(ch) (AD4851_REG_CHX_OFFSET_LSB(ch) + 0x01)
+#define AD4851_REG_CHX_OFFSET_MSB(ch) (AD4851_REG_CHX_OFFSET_MID(ch) + 0x01)
+#define AD4851_REG_CHX_GAIN(ch) (AD4851_REG_CHX_OFFSET(ch) + 0x03)
+#define AD4851_REG_CHX_GAIN_LSB(ch) AD4851_REG_CHX_GAIN(ch)
+#define AD4851_REG_CHX_GAIN_MSB(ch) (AD4851_REG_CHX_GAIN(ch) + 0x01)
+#define AD4851_REG_CHX_PHASE(ch) (AD4851_REG_CHX_GAIN(ch) + 0x02)
+#define AD4851_REG_CHX_PHASE_LSB(ch) AD4851_REG_CHX_PHASE(ch)
+#define AD4851_REG_CHX_PHASE_MSB(ch) (AD4851_REG_CHX_PHASE_LSB(ch) + 0x01)
+
+#define AD4851_REG_TESTPAT_0(c) (0x38 + (c) * 0x12)
+#define AD4851_REG_TESTPAT_1(c) (0x39 + (c) * 0x12)
+#define AD4851_REG_TESTPAT_2(c) (0x3A + (c) * 0x12)
+#define AD4851_REG_TESTPAT_3(c) (0x3B + (c) * 0x12)
+
+#define AD4851_SW_RESET (BIT(7) | BIT(0))
+#define AD4851_SDO_ENABLE BIT(4)
+#define AD4851_SINGLE_INSTRUCTION BIT(7)
+#define AD4851_ECHO_CLOCK_MODE BIT(0)
+
+#define AD4851_PACKET_FORMAT_0 0
+#define AD4851_PACKET_FORMAT_1 1
+#define AD4851_PACKET_FORMAT_MASK GENMASK(1, 0)
+
+#define AD4851_OS_EN_MSK BIT(7)
+#define AD4851_OS_RATIO_MSK GENMASK(3, 0)
+
+#define AD4851_TEST_PAT BIT(2)
+
+#define AD4858_PACKET_SIZE_20 0
+#define AD4858_PACKET_SIZE_24 1
+#define AD4858_PACKET_SIZE_32 2
+
+#define AD4857_PACKET_SIZE_16 0
+#define AD4857_PACKET_SIZE_24 1
+
+#define AD4851_TESTPAT_0_DEFAULT 0x2A
+#define AD4851_TESTPAT_1_DEFAULT 0x3C
+#define AD4851_TESTPAT_2_DEFAULT 0xCE
+#define AD4851_TESTPAT_3_DEFAULT(c) (0x0A + (0x10 * (c)))
+
+#define AD4851_SOFTSPAN_0V_2V5 0
+#define AD4851_SOFTSPAN_N2V5_2V5 1
+#define AD4851_SOFTSPAN_0V_5V 2
+#define AD4851_SOFTSPAN_N5V_5V 3
+#define AD4851_SOFTSPAN_0V_6V25 4
+#define AD4851_SOFTSPAN_N6V25_6V25 5
+#define AD4851_SOFTSPAN_0V_10V 6
+#define AD4851_SOFTSPAN_N10V_10V 7
+#define AD4851_SOFTSPAN_0V_12V5 8
+#define AD4851_SOFTSPAN_N12V5_12V5 9
+#define AD4851_SOFTSPAN_0V_20V 10
+#define AD4851_SOFTSPAN_N20V_20V 11
+#define AD4851_SOFTSPAN_0V_25V 12
+#define AD4851_SOFTSPAN_N25V_25V 13
+#define AD4851_SOFTSPAN_0V_40V 14
+#define AD4851_SOFTSPAN_N40V_40V 15
+
+#define AD4851_MAX_LANES 8
+#define AD4851_MAX_IODELAY 32
+
+#define AD4851_T_CNVH_NS 40
+
+struct ad4851_chip_info {
+ const char *name;
+ unsigned int product_id;
+ const unsigned int (*scale_table)[2];
+ int num_scales;
+ const int *offset_table;
+ int num_offset;
+ const struct iio_chan_spec *channels;
+ unsigned int num_channels;
+ unsigned long throughput;
+ unsigned int resolution;
+};
+
+struct ad4851_state {
+ struct spi_device *spi;
+ struct pwm_device *cnv;
+ struct iio_backend *back;
+ /*
+ * Synchronize access to members the of driver state, and ensure
+ * atomicity of consecutive regmap operations.
+ */
+ struct mutex lock;
+ struct regmap *regmap;
+ const struct ad4851_chip_info *info;
+ struct gpio_desc *pd_gpio;
+ unsigned long sampling_freq;
+ unsigned int (*scales)[2];
+ int *offsets;
+};
+
+static int ad4851_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg,
+ unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ad4851_state *st = iio_priv(indio_dev);
+
+ if (readval)
+ return regmap_read(st->regmap, reg, readval);
+
+ return regmap_write(st->regmap, reg, writeval);
+}
+
+static int ad4851_set_sampling_freq(struct ad4851_state *st, unsigned int freq)
+{
+ struct pwm_state cnv_state = {
+ .duty_cycle = AD4851_T_CNVH_NS,
+ .enabled = true,
+ };
+ int ret;
+
+ freq = clamp(freq, 1, st->info->throughput);
+
+ cnv_state.period = DIV_ROUND_CLOSEST_ULL(GIGA, freq);
+
+ ret = pwm_apply_might_sleep(st->cnv, &cnv_state);
+ if (ret)
+ return ret;
+
+ st->sampling_freq = freq;
+
+ return 0;
+}
+
+static const int ad4851_oversampling_ratios[] = {
+ 1,
+ 2,
+ 4,
+ 8,
+ 16,
+ 32,
+ 64,
+ 128,
+ 256,
+ 512,
+ 1024,
+ 2048,
+ 4096,
+ 8192,
+ 16384,
+ 32768,
+ 65536,
+};
+
+static int ad4851_osr_to_regval(int ratio)
+{
+ int i;
+
+ for (i = 1; i < ARRAY_SIZE(ad4851_oversampling_ratios); i++)
+ if (ratio == ad4851_oversampling_ratios[i])
+ return i - 1;
+
+ return -EINVAL;
+}
+
+static int ad4851_set_oversampling_ratio(struct ad4851_state *st,
+ const struct iio_chan_spec *chan,
+ unsigned int osr)
+{
+ unsigned int val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ if (osr == 1) {
+ ret = regmap_update_bits(st->regmap, AD4851_REG_OVERSAMPLE,
+ AD4851_OS_EN_MSK, 0);
+ if (ret)
+ return ret;
+ } else {
+ ret = regmap_update_bits(st->regmap, AD4851_REG_OVERSAMPLE,
+ AD4851_OS_EN_MSK, AD4851_OS_EN_MSK);
+ if (ret)
+ return ret;
+
+ val = ad4851_osr_to_regval(osr);
+ if (val < 0)
+ return -EINVAL;
+
+ ret = regmap_update_bits(st->regmap, AD4851_REG_OVERSAMPLE,
+ AD4851_OS_RATIO_MSK, val);
+ if (ret)
+ return ret;
+ }
+
+ switch (chan->scan_type.realbits) {
+ case 20:
+ switch (osr) {
+ case 1:
+ val = 20;
+ break;
+ default:
+ val = 24;
+ break;
+ }
+ break;
+ case 16:
+ val = 16;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = iio_backend_data_size_set(st->back, val);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(st->regmap, AD4851_REG_PACKET,
+ AD4851_PACKET_FORMAT_MASK, (osr == 1) ? 0 : 1);
+}
+
+static int ad4851_get_oversampling_ratio(struct ad4851_state *st, unsigned int *val)
+{
+ unsigned int osr;
+ int ret;
+
+ ret = regmap_read(st->regmap, AD4851_REG_OVERSAMPLE, &osr);
+ if (ret)
+ return ret;
+
+ if (!FIELD_GET(AD4851_OS_EN_MSK, osr))
+ *val = 1;
+ else
+ *val = ad4851_oversampling_ratios[FIELD_GET(AD4851_OS_RATIO_MSK, osr)];
+
+ return IIO_VAL_INT;
+}
+
+static int ad4851_setup(struct ad4851_state *st)
+{
+ unsigned int product_id;
+ int ret;
+
+ ret = ad4851_set_sampling_freq(st, HZ_PER_MHZ);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_INTERFACE_CONFIG_A,
+ AD4851_SW_RESET);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_INTERFACE_CONFIG_B,
+ AD4851_SINGLE_INSTRUCTION);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_INTERFACE_CONFIG_A,
+ AD4851_SDO_ENABLE);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->regmap, AD4851_REG_PRODUCT_ID_L, &product_id);
+ if (ret)
+ return ret;
+
+ if (product_id != st->info->product_id)
+ dev_info(&st->spi->dev, "Unknown product ID: 0x%02X\n",
+ product_id);
+
+ ret = regmap_write(st->regmap, AD4851_REG_DEVICE_CTRL,
+ AD4851_ECHO_CLOCK_MODE);
+ if (ret)
+ return ret;
+
+ return regmap_write(st->regmap, AD4851_REG_PACKET, 0);
+}
+
+static int ad4851_find_opt(bool *field, u32 size, u32 *ret_start)
+{
+ unsigned int i, cnt = 0, max_cnt = 0, max_start = 0;
+ int start;
+
+ for (i = 0, start = -1; i < size; i++) {
+ if (field[i] == 0) {
+ if (start == -1)
+ start = i;
+ cnt++;
+ } else {
+ if (cnt > max_cnt) {
+ max_cnt = cnt;
+ max_start = start;
+ }
+ start = -1;
+ cnt = 0;
+ }
+ }
+
+ if (cnt > max_cnt) {
+ max_cnt = cnt;
+ max_start = start;
+ }
+
+ if (!max_cnt)
+ return -ENOENT;
+
+ *ret_start = max_start;
+
+ return max_cnt;
+}
+
+static int ad4851_calibrate(struct ad4851_state *st)
+{
+ unsigned int opt_delay, lane_num, delay, i, s, c;
+ enum iio_backend_interface_type interface_type;
+ DECLARE_BITMAP(pn_status, AD4851_MAX_LANES * AD4851_MAX_IODELAY);
+ bool status;
+ int ret;
+
+ ret = iio_backend_interface_type_get(st->back, &interface_type);
+ if (ret)
+ return ret;
+
+ switch (interface_type) {
+ case IIO_BACKEND_INTERFACE_CMOS:
+ lane_num = st->info->num_channels;
+ break;
+ case IIO_BACKEND_INTERFACE_LVDS:
+ lane_num = 1;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (st->info->resolution == 16) {
+ ret = iio_backend_data_size_set(st->back, 24);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_PACKET,
+ AD4851_TEST_PAT | AD4857_PACKET_SIZE_24);
+ if (ret)
+ return ret;
+ } else {
+ ret = iio_backend_data_size_set(st->back, 32);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_PACKET,
+ AD4851_TEST_PAT | AD4858_PACKET_SIZE_32);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < st->info->num_channels; i++) {
+ ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_0(i),
+ AD4851_TESTPAT_0_DEFAULT);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_1(i),
+ AD4851_TESTPAT_1_DEFAULT);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_2(i),
+ AD4851_TESTPAT_2_DEFAULT);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_3(i),
+ AD4851_TESTPAT_3_DEFAULT(i));
+ if (ret)
+ return ret;
+
+ ret = iio_backend_chan_enable(st->back, i);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < lane_num; i++) {
+ for (delay = 0; delay < AD4851_MAX_IODELAY; delay++) {
+ ret = iio_backend_iodelay_set(st->back, i, delay);
+ if (ret)
+ return ret;
+ ret = iio_backend_chan_status(st->back, i, &status);
+ if (ret)
+ return ret;
+
+ if (status)
+ set_bit(i * AD4851_MAX_IODELAY + delay, pn_status);
+ else
+ clear_bit(i * AD4851_MAX_IODELAY + delay, pn_status);
+ }
+ }
+
+ for (i = 0; i < lane_num; i++) {
+ status = test_bit(i * AD4851_MAX_IODELAY, pn_status);
+ c = ad4851_find_opt(&status, AD4851_MAX_IODELAY, &s);
+ if (c < 0)
+ return c;
+
+ opt_delay = s + c / 2;
+ ret = iio_backend_iodelay_set(st->back, i, opt_delay);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < st->info->num_channels; i++) {
+ ret = iio_backend_chan_disable(st->back, i);
+ if (ret)
+ return ret;
+ }
+
+ ret = iio_backend_data_size_set(st->back, 20);
+ if (ret)
+ return ret;
+
+ return regmap_write(st->regmap, AD4851_REG_PACKET, 0);
+}
+
+static int ad4851_get_calibscale(struct ad4851_state *st, int ch, int *val, int *val2)
+{
+ unsigned int reg_val;
+ int gain;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_GAIN_MSB(ch),
+ &reg_val);
+ if (ret)
+ return ret;
+
+ gain = (reg_val & 0xFF) << 8;
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_GAIN_LSB(ch),
+ &reg_val);
+ if (ret)
+ return ret;
+
+ gain |= reg_val & 0xFF;
+
+ *val = gain;
+ *val2 = 32768;
+
+ return IIO_VAL_FRACTIONAL;
+}
+
+static int ad4851_set_calibscale(struct ad4851_state *st, int ch, int val,
+ int val2)
+{
+ unsigned long long gain;
+ u8 buf[0];
+ int ret;
+
+ if (val < 0 || val2 < 0)
+ return -EINVAL;
+
+ gain = val * MICRO + val2;
+ gain = DIV_U64_ROUND_CLOSEST(gain * 32768, MICRO);
+
+ put_unaligned_be16(gain, buf);
+
+ guard(mutex)(&st->lock);
+
+ ret = regmap_write(st->regmap, AD4851_REG_CHX_GAIN_MSB(ch),
+ buf[0]);
+ if (ret)
+ return ret;
+
+ return regmap_write(st->regmap, AD4851_REG_CHX_GAIN_LSB(ch),
+ buf[1]);
+}
+
+static int ad4851_get_calibbias(struct ad4851_state *st, int ch, int *val)
+{
+ unsigned int lsb, mid, msb;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_MSB(ch),
+ &msb);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_MID(ch),
+ &mid);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_LSB(ch),
+ &lsb);
+ if (ret)
+ return ret;
+
+ if (st->info->resolution == 16) {
+ *val = msb << 8;
+ *val |= mid;
+ *val = sign_extend32(*val, 15);
+ } else {
+ *val = msb << 12;
+ *val |= mid << 4;
+ *val |= lsb >> 4;
+ *val = sign_extend32(*val, 19);
+ }
+
+ return IIO_VAL_INT;
+}
+
+static int ad4851_set_calibbias(struct ad4851_state *st, int ch, int val)
+{
+ u8 buf[3] = { 0 };
+ int ret;
+
+ if (val < 0)
+ return -EINVAL;
+
+ if (st->info->resolution == 16)
+ put_unaligned_be16(val, buf);
+ else
+ put_unaligned_be24(val << 4, buf);
+
+ guard(mutex)(&st->lock);
+
+ ret = regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_LSB(ch), buf[2]);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_MID(ch), buf[1]);
+ if (ret)
+ return ret;
+
+ return regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_MSB(ch), buf[0]);
+}
+
+static const unsigned int ad4851_scale_table[][2] = {
+ { 2500, 0x0 },
+ { 5000, 0x1 },
+ { 5000, 0x2 },
+ { 10000, 0x3 },
+ { 6250, 0x04 },
+ { 12500, 0x5 },
+ { 10000, 0x6 },
+ { 20000, 0x7 },
+ { 12500, 0x8 },
+ { 25000, 0x9 },
+ { 20000, 0xA },
+ { 40000, 0xB },
+ { 25000, 0xC },
+ { 50000, 0xD },
+ { 40000, 0xE },
+ { 80000, 0xF },
+};
+
+static const int ad4857_offset_table[] = {
+ 0, -32768,
+};
+
+static const int ad4858_offset_table[] = {
+ 0, -524288,
+};
+
+static const unsigned int ad4851_scale_avail[] = {
+ 2500, 5000,
+ 10000, 6250,
+ 12500, 20000,
+ 25000, 40000,
+ 50000, 80000,
+};
+
+static void __ad4851_get_scale(struct ad4851_state *st, int scale_tbl,
+ unsigned int *val, unsigned int *val2)
+{
+ const struct ad4851_chip_info *info = st->info;
+ const struct iio_chan_spec *chan = &info->channels[0];
+ unsigned int tmp;
+
+ tmp = ((unsigned long long)scale_tbl * MICRO) >> chan->scan_type.realbits;
+ *val = tmp / MICRO;
+ *val2 = tmp % MICRO;
+}
+
+static int ad4851_set_scale(struct ad4851_state *st,
+ const struct iio_chan_spec *chan, int val, int val2)
+{
+ unsigned int scale_val[2];
+ unsigned int i;
+ bool single_ended = false;
+
+ for (i = 0; i < ARRAY_SIZE(ad4851_scale_table); i++) {
+ __ad4851_get_scale(st, ad4851_scale_table[i][0],
+ &scale_val[0], &scale_val[1]);
+ if (scale_val[0] != val || scale_val[1] != val2)
+ continue;
+
+ /*
+ * Adjust the softspan value (differential or single ended)
+ * based on the scale value selected and current offset of
+ * the channel.
+ *
+ * If the offset is 0 then continue iterations until finding
+ * the next matching scale value which always corresponds to
+ * the single ended mode.
+ */
+ if (!st->offsets[chan->channel] && !single_ended) {
+ single_ended = true;
+ continue;
+ }
+
+ return regmap_write(st->regmap,
+ AD4851_REG_CHX_SOFTSPAN(chan->channel),
+ ad4851_scale_table[i][1]);
+ }
+
+ return -EINVAL;
+}
+
+static int ad4851_get_scale(struct ad4851_state *st,
+ const struct iio_chan_spec *chan, int *val,
+ int *val2)
+{
+ unsigned int i, softspan_val;
+ int ret;
+
+ ret = regmap_read(st->regmap, AD4851_REG_CHX_SOFTSPAN(chan->channel),
+ &softspan_val);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(ad4851_scale_table); i++) {
+ if (softspan_val == ad4851_scale_table[i][1])
+ break;
+ }
+
+ if (i == ARRAY_SIZE(ad4851_scale_table))
+ return -EIO;
+
+ __ad4851_get_scale(st, ad4851_scale_table[i][0], val, val2);
+
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int ad4851_set_offset(struct ad4851_state *st,
+ const struct iio_chan_spec *chan, int val)
+{
+ guard(mutex)(&st->lock);
+
+ if (val != st->offsets[chan->channel])
+ return 0;
+
+ st->offsets[chan->channel] = val;
+ /* Restore to the default range if offset changes */
+ if (st->offsets[chan->channel])
+ return regmap_write(st->regmap,
+ AD4851_REG_CHX_SOFTSPAN(chan->channel),
+ AD4851_SOFTSPAN_N40V_40V);
+ return regmap_write(st->regmap,
+ AD4851_REG_CHX_SOFTSPAN(chan->channel),
+ AD4851_SOFTSPAN_0V_40V);
+}
+
+static int ad4851_scale_offset_fill(struct ad4851_state *st)
+{
+ unsigned int i, val1, val2;
+
+ st->offsets = devm_kcalloc(&st->spi->dev, st->info->num_channels,
+ sizeof(*st->offsets), GFP_KERNEL);
+ if (!st->offsets)
+ return -ENOMEM;
+
+ st->scales = devm_kmalloc_array(&st->spi->dev, ARRAY_SIZE(ad4851_scale_avail),
+ sizeof(*st->scales), GFP_KERNEL);
+ if (!st->scales)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(ad4851_scale_avail); i++) {
+ __ad4851_get_scale(st, ad4851_scale_avail[i], &val1, &val2);
+ st->scales[i][0] = val1;
+ st->scales[i][1] = val2;
+ }
+
+ return 0;
+}
+
+static int ad4851_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long info)
+{
+ struct ad4851_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = st->sampling_freq;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return ad4851_get_calibscale(st, chan->channel, val, val2);
+ case IIO_CHAN_INFO_SCALE:
+ return ad4851_get_scale(st, chan, val, val2);
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return ad4851_get_calibbias(st, chan->channel, val);
+ case IIO_CHAN_INFO_OFFSET:
+ scoped_guard(mutex, &st->lock)
+ *val = st->offsets[chan->channel];
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ return ad4851_get_oversampling_ratio(st, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4851_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long info)
+{
+ struct ad4851_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return ad4851_set_sampling_freq(st, val);
+ case IIO_CHAN_INFO_SCALE:
+ return ad4851_set_scale(st, chan, val, val2);
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return ad4851_set_calibscale(st, chan->channel, val, val2);
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return ad4851_set_calibbias(st, chan->channel, val);
+ case IIO_CHAN_INFO_OFFSET:
+ return ad4851_set_offset(st, chan, val);
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ return ad4851_set_oversampling_ratio(st, chan, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad4851_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct ad4851_state *st = iio_priv(indio_dev);
+ unsigned int c;
+ int ret;
+
+ for (c = 0; c < st->info->num_channels; c++) {
+ if (test_bit(c, scan_mask))
+ ret = iio_backend_chan_enable(st->back, c);
+ else
+ ret = iio_backend_chan_disable(st->back, c);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ad4851_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct ad4851_state *st = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (const int *)st->scales;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ /* Values are stored in a 2D matrix */
+ *length = ARRAY_SIZE(ad4851_scale_avail) * 2;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_OFFSET:
+ *vals = st->info->offset_table;
+ *type = IIO_VAL_INT;
+ *length = st->info->num_offset;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *vals = ad4851_oversampling_ratios;
+ *length = ARRAY_SIZE(ad4851_oversampling_ratios);
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+#define AD4851_IIO_CHANNEL(index, real, storage) \
+{ \
+ .type = IIO_VOLTAGE, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
+ BIT(IIO_CHAN_INFO_CALIBBIAS) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+ .info_mask_shared_by_type_available = \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET) | \
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+ .indexed = 1, \
+ .channel = index, \
+ .scan_index = index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = real, \
+ .storagebits = storage, \
+ }, \
+}
+
+static const struct iio_chan_spec ad4858_channels[] = {
+ AD4851_IIO_CHANNEL(0, 20, 32),
+ AD4851_IIO_CHANNEL(1, 20, 32),
+ AD4851_IIO_CHANNEL(2, 20, 32),
+ AD4851_IIO_CHANNEL(3, 20, 32),
+ AD4851_IIO_CHANNEL(4, 20, 32),
+ AD4851_IIO_CHANNEL(5, 20, 32),
+ AD4851_IIO_CHANNEL(6, 20, 32),
+ AD4851_IIO_CHANNEL(7, 20, 32),
+};
+
+static const struct iio_chan_spec ad4857_channels[] = {
+ AD4851_IIO_CHANNEL(0, 16, 16),
+ AD4851_IIO_CHANNEL(1, 16, 16),
+ AD4851_IIO_CHANNEL(2, 16, 16),
+ AD4851_IIO_CHANNEL(3, 16, 16),
+ AD4851_IIO_CHANNEL(4, 16, 16),
+ AD4851_IIO_CHANNEL(5, 16, 16),
+ AD4851_IIO_CHANNEL(6, 16, 16),
+ AD4851_IIO_CHANNEL(7, 16, 16),
+};
+
+static const struct ad4851_chip_info ad4851_info = {
+ .name = "ad4851",
+ .product_id = 0x67,
+ .offset_table = ad4857_offset_table,
+ .num_offset = ARRAY_SIZE(ad4857_offset_table),
+ .channels = ad4857_channels,
+ .num_channels = ARRAY_SIZE(ad4857_channels),
+ .throughput = 250 * KILO,
+ .resolution = 16,
+};
+
+static const struct ad4851_chip_info ad4852_info = {
+ .name = "ad4852",
+ .product_id = 0x66,
+ .offset_table = ad4858_offset_table,
+ .num_offset = ARRAY_SIZE(ad4858_offset_table),
+ .channels = ad4858_channels,
+ .num_channels = ARRAY_SIZE(ad4858_channels),
+ .throughput = 250 * KILO,
+ .resolution = 20,
+};
+
+static const struct ad4851_chip_info ad4853_info = {
+ .name = "ad4853",
+ .product_id = 0x65,
+ .offset_table = ad4857_offset_table,
+ .num_offset = ARRAY_SIZE(ad4857_offset_table),
+ .channels = ad4857_channels,
+ .num_channels = ARRAY_SIZE(ad4857_channels),
+ .throughput = 1 * MEGA,
+ .resolution = 16,
+};
+
+static const struct ad4851_chip_info ad4854_info = {
+ .name = "ad4854",
+ .product_id = 0x64,
+ .offset_table = ad4858_offset_table,
+ .num_offset = ARRAY_SIZE(ad4858_offset_table),
+ .channels = ad4858_channels,
+ .num_channels = ARRAY_SIZE(ad4858_channels),
+ .throughput = 1 * MEGA,
+ .resolution = 20,
+};
+
+static const struct ad4851_chip_info ad4855_info = {
+ .name = "ad4855",
+ .product_id = 0x63,
+ .offset_table = ad4857_offset_table,
+ .num_offset = ARRAY_SIZE(ad4857_offset_table),
+ .channels = ad4857_channels,
+ .num_channels = ARRAY_SIZE(ad4857_channels),
+ .throughput = 250 * KILO,
+ .resolution = 16,
+};
+
+static const struct ad4851_chip_info ad4856_info = {
+ .name = "ad4856",
+ .product_id = 0x62,
+ .offset_table = ad4858_offset_table,
+ .num_offset = ARRAY_SIZE(ad4858_offset_table),
+ .channels = ad4858_channels,
+ .num_channels = ARRAY_SIZE(ad4858_channels),
+ .throughput = 250 * KILO,
+ .resolution = 20,
+};
+
+static const struct ad4851_chip_info ad4857_info = {
+ .name = "ad4857",
+ .product_id = 0x61,
+ .offset_table = ad4857_offset_table,
+ .num_offset = ARRAY_SIZE(ad4857_offset_table),
+ .channels = ad4857_channels,
+ .num_channels = ARRAY_SIZE(ad4857_channels),
+ .throughput = 1 * MEGA,
+ .resolution = 16,
+};
+
+static const struct ad4851_chip_info ad4858_info = {
+ .name = "ad4858",
+ .product_id = 0x60,
+ .offset_table = ad4858_offset_table,
+ .num_offset = ARRAY_SIZE(ad4858_offset_table),
+ .channels = ad4858_channels,
+ .num_channels = ARRAY_SIZE(ad4858_channels),
+ .throughput = 1 * MEGA,
+ .resolution = 20,
+};
+
+static const struct ad4851_chip_info ad4858i_info = {
+ .name = "ad4858i",
+ .product_id = 0x6F,
+ .offset_table = ad4858_offset_table,
+ .num_offset = ARRAY_SIZE(ad4858_offset_table),
+ .channels = ad4858_channels,
+ .num_channels = ARRAY_SIZE(ad4858_channels),
+ .throughput = 1 * MEGA,
+ .resolution = 20,
+};
+
+static const struct iio_info ad4851_iio_info = {
+ .debugfs_reg_access = ad4851_reg_access,
+ .read_raw = ad4851_read_raw,
+ .write_raw = ad4851_write_raw,
+ .update_scan_mode = ad4851_update_scan_mode,
+ .read_avail = ad4851_read_avail,
+};
+
+static const struct regmap_config regmap_config = {
+ .reg_bits = 16,
+ .val_bits = 8,
+ .read_flag_mask = BIT(7),
+};
+
+static const char * const ad4851_power_supplies[] = {
+ "vcc", "vdd", "vee", "vio",
+};
+
+static int ad4851_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct ad4851_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ ret = devm_mutex_init(&spi->dev, &st->lock);
+ if (ret)
+ return ret;
+
+ ret = devm_regulator_bulk_get_enable(&spi->dev,
+ ARRAY_SIZE(ad4851_power_supplies),
+ ad4851_power_supplies);
+ if (ret)
+ return dev_err_probe(&spi->dev, ret,
+ "failed to get and enable supplies\n");
+
+ ret = devm_regulator_get_enable_optional(&spi->dev, "vddh");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(&spi->dev, ret, "failed to get vddh voltage\n");
+
+ ret = devm_regulator_get_enable_optional(&spi->dev, "vddl");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(&spi->dev, ret, "failed to get vddl voltage\n");
+
+ ret = devm_regulator_get_enable_optional(&spi->dev, "vrefbuf");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(&spi->dev, ret, "failed to get vrefbuf voltage\n");
+
+ ret = devm_regulator_get_enable_optional(&spi->dev, "vddl");
+ if (ret < 0 && ret != -ENODEV)
+ return dev_err_probe(&spi->dev, ret, "failed to get vrefio voltage\n");
+
+ st->pd_gpio = devm_gpiod_get_optional(&spi->dev, "pd", GPIOD_OUT_LOW);
+ if (IS_ERR(st->pd_gpio))
+ return dev_err_probe(&spi->dev, PTR_ERR(st->pd_gpio),
+ "Error on requesting pd GPIO\n");
+
+ st->cnv = devm_pwm_get(&spi->dev, NULL);
+ if (IS_ERR(st->cnv))
+ return dev_err_probe(&spi->dev, PTR_ERR(st->cnv),
+ "Error on requesting pwm\n");
+
+ st->info = spi_get_device_match_data(spi);
+ if (!st->info)
+ return -ENODEV;
+
+ st->regmap = devm_regmap_init_spi(spi, &regmap_config);
+ if (IS_ERR(st->regmap))
+ return PTR_ERR(st->regmap);
+
+ ret = ad4851_scale_offset_fill(st);
+ if (ret)
+ return ret;
+
+ ret = ad4851_setup(st);
+ if (ret)
+ return ret;
+
+ indio_dev->name = st->info->name;
+ indio_dev->channels = st->info->channels;
+ indio_dev->num_channels = st->info->num_channels;
+ indio_dev->info = &ad4851_iio_info;
+
+ st->back = devm_iio_backend_get(&spi->dev, NULL);
+ if (IS_ERR(st->back))
+ return PTR_ERR(st->back);
+
+ ret = devm_iio_backend_request_buffer(&spi->dev, st->back, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_backend_enable(&spi->dev, st->back);
+ if (ret)
+ return ret;
+
+ ret = ad4851_calibrate(st);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ad4851_of_match[] = {
+ { .compatible = "adi,ad4858", .data = &ad4851_info, },
+ { .compatible = "adi,ad4857", .data = &ad4852_info, },
+ { .compatible = "adi,ad4856", .data = &ad4853_info, },
+ { .compatible = "adi,ad4855", .data = &ad4854_info, },
+ { .compatible = "adi,ad4854", .data = &ad4855_info, },
+ { .compatible = "adi,ad4853", .data = &ad4856_info, },
+ { .compatible = "adi,ad4852", .data = &ad4857_info, },
+ { .compatible = "adi,ad4851", .data = &ad4858_info, },
+ { .compatible = "adi,ad4858i", .data = &ad4858i_info, },
+ {}
+};
+
+static const struct spi_device_id ad4851_spi_id[] = {
+ { "ad4851", (kernel_ulong_t)&ad4851_info },
+ { "ad4852", (kernel_ulong_t)&ad4852_info },
+ { "ad4853", (kernel_ulong_t)&ad4853_info },
+ { "ad4854", (kernel_ulong_t)&ad4854_info },
+ { "ad4855", (kernel_ulong_t)&ad4855_info },
+ { "ad4856", (kernel_ulong_t)&ad4856_info },
+ { "ad4857", (kernel_ulong_t)&ad4857_info },
+ { "ad4858", (kernel_ulong_t)&ad4858_info },
+ { "ad4858i", (kernel_ulong_t)&ad4858i_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad4851_spi_id);
+
+static struct spi_driver ad4851_driver = {
+ .probe = ad4851_probe,
+ .driver = {
+ .name = "ad4851",
+ .of_match_table = ad4851_of_match,
+ },
+ .id_table = ad4851_spi_id,
+};
+module_spi_driver(ad4851_driver);
+
+MODULE_AUTHOR("Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>");
+MODULE_AUTHOR("Dragos Bogdan <dragos.bogdan@xxxxxxxxxx>");
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD4851 DAS driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_BACKEND);
--
2.46.2