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From:   Alexandru Ardelean <ardeleanalex@gmail.com>
Date:   Thu, 22 Jul 2021 10:10:33 +0300
Message-ID: <CA+U=DsqgNUh5Yek=uUstLLoP3eDYC8uCfjcQ09oW33nhu7SQCQ@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] iio: accel: Add driver support for ADXL355
To:     Puranjay Mohan <puranjay12@gmail.com>
Cc:     "Hennerich, Michael" <Michael.Hennerich@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        linux-iio <linux-iio@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        "Bogdan, Dragos" <Dragos.Bogdan@analog.com>,
        "Berghe, Darius" <Darius.Berghe@analog.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Jul 22, 2021 at 9:23 AM Puranjay Mohan <puranjay12@gmail.com> wrote:
>
> ADXL355 is 3-axis MEMS Accelerometer. It offers low noise density,
> low 0g offset drift, low power with selectable measurement ranges.
> It also features programmable high-pass and low-pass filters.
>

At a later point, someone else could integrate the ADXL354 support
into this driver.
The current code looks like it could do that without much hassle.
But that also requires testing on an ADXL354 chip.

Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>


> Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/adxl354_adxl355.pdf
> Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
> ---
>  MAINTAINERS                      |   7 +
>  drivers/iio/accel/Kconfig        |  29 ++
>  drivers/iio/accel/Makefile       |   3 +
>  drivers/iio/accel/adxl355.h      |  79 +++++
>  drivers/iio/accel/adxl355_core.c | 536 +++++++++++++++++++++++++++++++
>  drivers/iio/accel/adxl355_i2c.c  |  63 ++++
>  drivers/iio/accel/adxl355_spi.c  |  66 ++++
>  7 files changed, 783 insertions(+)
>  create mode 100644 drivers/iio/accel/adxl355.h
>  create mode 100644 drivers/iio/accel/adxl355_core.c
>  create mode 100644 drivers/iio/accel/adxl355_i2c.c
>  create mode 100644 drivers/iio/accel/adxl355_spi.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index bd7aff0c1..461f2a192 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -586,6 +586,13 @@ W: http://ez.analog.com/community/linux-device-drivers
>  F:     Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
>  F:     drivers/input/misc/adxl34x.c
>
> +ADXL355 THREE-AXIS DIGITAL ACCELEROMETER DRIVER
> +M:     Puranjay Mohan <puranjay12@gmail.com>
> +L:     linux-iio@vger.kernel.org
> +S:     Supported
> +F:     drivers/iio/accel/adxl34x.c
> +F:     Documentation/devicetree/bindings/iio/accel/adi,adxl355.yaml
> +
>  ADXL372 THREE-AXIS DIGITAL ACCELEROMETER DRIVER
>  M:     Michael Hennerich <michael.hennerich@analog.com>
>  S:     Supported
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index cceda3cec..9a65353a4 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -61,6 +61,35 @@ config ADXL345_SPI
>           will be called adxl345_spi and you will also get adxl345_core
>           for the core module.
>
> +config ADXL355
> +       tristate
> +
> +config ADXL355_I2C
> +       tristate "Analog Devices ADXL355 3-Axis Digital Accelerometer I2C Driver"
> +       depends on I2C
> +       select ADXL355
> +       select REGMAP_I2C
> +       help
> +         Say Y here if you want to build support for the Analog Devices
> +         ADXL355 3-axis digital accelerometer.
> +
> +         To compile this driver as a module, choose M here: the module
> +         will be called adxl355_i2c and you will also get adxl355_core
> +         for the core module.
> +
> +config ADXL355_SPI
> +       tristate "Analog Devices ADXL355 3-Axis Digital Accelerometer SPI Driver"
> +       depends on SPI
> +       select ADXL355
> +       select REGMAP_SPI
> +       help
> +         Say Y here if you want to build support for the Analog Devices
> +         ADXL355 3-axis digital accelerometer.
> +
> +         To compile this driver as a module, choose M here: the module
> +         will be called adxl355_spi and you will also get adxl355_core
> +         for the core module.
> +
>  config ADXL372
>         tristate
>         select IIO_BUFFER
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 32cd1342a..0e4721d2d 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -9,6 +9,9 @@ obj-$(CONFIG_ADIS16209) += adis16209.o
>  obj-$(CONFIG_ADXL345) += adxl345_core.o
>  obj-$(CONFIG_ADXL345_I2C) += adxl345_i2c.o
>  obj-$(CONFIG_ADXL345_SPI) += adxl345_spi.o
> +obj-$(CONFIG_ADXL355) += adxl355_core.o
> +obj-$(CONFIG_ADXL355_I2C) += adxl355_i2c.o
> +obj-$(CONFIG_ADXL355_SPI) += adxl355_spi.o
>  obj-$(CONFIG_ADXL372) += adxl372.o
>  obj-$(CONFIG_ADXL372_I2C) += adxl372_i2c.o
>  obj-$(CONFIG_ADXL372_SPI) += adxl372_spi.o
> diff --git a/drivers/iio/accel/adxl355.h b/drivers/iio/accel/adxl355.h
> new file mode 100644
> index 000000000..e0b1e697f
> --- /dev/null
> +++ b/drivers/iio/accel/adxl355.h
> @@ -0,0 +1,79 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * ADXL355 3-Axis Digital Accelerometer
> + *
> + * Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
> + */
> +
> +#ifndef _ADXL355_H_
> +#define _ADXL355_H_
> +
> +#include <linux/regmap.h>
> +
> +/* ADXL355 Register Definitions */
> +#define ADXL355_DEVID_AD       0x00
> +#define ADXL355_DEVID_MST      0x01
> +#define ADXL355_PARTID         0x02
> +#define ADXL355_REVID          0x03
> +#define ADXL355_STATUS         0x04
> +#define ADXL355_FIFO_ENTRIES   0x05
> +#define ADXL355_TEMP2          0x06
> +#define ADXL355_XDATA3         0x08
> +#define ADXL355_YDATA3         0x0B
> +#define ADXL355_ZDATA3         0x0E
> +#define ADXL355_FIFO_DATA      0x11
> +#define ADXL355_OFFSET_X_H     0x1E
> +#define ADXL355_OFFSET_Y_H     0x20
> +#define ADXL355_OFFSET_Z_H     0x22
> +#define ADXL355_ACT_EN         0x24
> +#define ADXL355_ACT_THRESH_H   0x25
> +#define ADXL355_ACT_THRESH_L   0x26
> +#define ADXL355_ACT_COUNT      0x27
> +#define ADXL355_FILTER         0x28
> +#define ADXL355_FIFO_SAMPLES   0x29
> +#define ADXL355_INT_MAP                0x2A
> +#define ADXL355_SYNC           0x2B
> +#define ADXL355_RANGE          0x2C
> +#define ADXL355_POWER_CTL      0x2D
> +#define ADXL355_SELF_TEST      0x2E
> +#define ADXL355_RESET          0x2F
> +
> +#define ADXL355_DEVID_AD_VAL   0xAD
> +#define ADXL355_DEVID_MST_VAL  0x1D
> +#define ADXL355_PARTID_VAL     0xED
> +#define ADXL355_REVID_VAL      0x01
> +#define ADXL355_RESET_CODE     0x52
> +
> +#define ADXL355_POWER_CTL_MODE_MSK     GENMASK(1, 0)
> +
> +#define ADXL355_FILTER_ODR_MSK                 GENMASK(3, 0)
> +#define ADXL355_FILTER_ODR_MODE(x)             ((x) & 0xF)
> +#define ADXL355_FILTER_HPF_MSK                 GENMASK(6, 4)
> +#define ADXL355_FILTER_HPF_MODE(x)             (((x) & 0x7) << 4)
> +
> +/*
> + * The datasheet defines an intercept of 1885 LSB at 25 degC
> + * and a slope of -9.05 LSB/C. The following formula can be used to find the
> + * temperature:
> + * Temp = ((RAW - 1885)/(-9.05)) + 25 but this doesn't follow the format of
> + * the IIO which is Temp = (RAW + OFFSET) * SCALE. Hence using some rearranging
> + * we get the scale as -110.49723 and offset as -2111.25
> + */
> +#define TEMP_SCALE_VAL -110
> +#define TEMP_SCALE_VAL2 497238
> +#define TEMP_OFFSET_VAL -2111
> +#define TEMP_OFFSET_VAL2 250000
> +
> +/*
> + * At +/- 2g with 20-bit resolution, scale is given in datasheet as
> + * 3.9ug/LSB = 0.0000039 * 9.80665 = 0.00003824593 m/s^2
> + */
> +#define ADXL355_NSCALE 38245
> +
> +extern const struct regmap_access_table adxl355_readable_regs_tbl;
> +
> +extern const struct regmap_access_table adxl355_writeable_regs_tbl;
> +
> +int adxl355_core_probe(struct device *dev, struct regmap *regmap,
> +                      const char *name);
> +#endif /* _ADXL355_H_ */
> diff --git a/drivers/iio/accel/adxl355_core.c b/drivers/iio/accel/adxl355_core.c
> new file mode 100644
> index 000000000..fa0370d41
> --- /dev/null
> +++ b/drivers/iio/accel/adxl355_core.c
> @@ -0,0 +1,536 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ADXL355 3-Axis Digital Accelerometer IIO core driver
> + *
> + * Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
> + *
> + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/adxl354_adxl355.pdf
> + */
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/limits.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include "adxl355.h"
> +
> +static const struct regmap_range adxl355_read_reg_range[] = {
> +       regmap_reg_range(ADXL355_DEVID_AD, ADXL355_FIFO_DATA),
> +       regmap_reg_range(ADXL355_OFFSET_X_H, ADXL355_SELF_TEST)
> +};
> +
> +const struct regmap_access_table adxl355_readable_regs_tbl = {
> +       .yes_ranges = adxl355_read_reg_range,
> +       .n_yes_ranges = ARRAY_SIZE(adxl355_read_reg_range),
> +};
> +EXPORT_SYMBOL_GPL(adxl355_readable_regs_tbl);
> +
> +static const struct regmap_range adxl355_write_reg_range[] = {
> +       regmap_reg_range(ADXL355_OFFSET_X_H, ADXL355_RESET)
> +};
> +
> +const struct regmap_access_table adxl355_writeable_regs_tbl = {
> +       .yes_ranges = adxl355_write_reg_range,
> +       .n_yes_ranges = ARRAY_SIZE(adxl355_write_reg_range),
> +};
> +EXPORT_SYMBOL_GPL(adxl355_writeable_regs_tbl);
> +
> +enum adxl355_op_mode {
> +       ADXL355_MEASUREMENT,
> +       ADXL355_STANDBY,
> +       ADXL355_TEMP_OFF
> +};
> +
> +enum adxl355_odr {
> +       ADXL355_ODR_4000HZ,
> +       ADXL355_ODR_2000HZ,
> +       ADXL355_ODR_1000HZ,
> +       ADXL355_ODR_500HZ,
> +       ADXL355_ODR_250HZ,
> +       ADXL355_ODR_125HZ,
> +       ADXL355_ODR_62_5HZ,
> +       ADXL355_ODR_31_25HZ,
> +       ADXL355_ODR_15_625HZ,
> +       ADXL355_ODR_7_813HZ,
> +       ADXL355_ODR_3_906HZ
> +};
> +
> +enum adxl355_hpf_3db {
> +       ADXL355_HPF_OFF,
> +       ADXL355_HPF_24_7,
> +       ADXL355_HPF_6_2084,
> +       ADXL355_HPF_1_5545,
> +       ADXL355_HPF_0_3862,
> +       ADXL355_HPF_0_0954,
> +       ADXL355_HPF_0_0238
> +};
> +
> +static const int adxl355_odr_table[][2] = {
> +       [0] = {4000, 0},
> +       [1] = {2000, 0},
> +       [2] = {1000, 0},
> +       [3] = {500, 0},
> +       [4] = {250, 0},
> +       [5] = {125, 0},
> +       [6] = {62, 500000},
> +       [7] = {31, 250000},
> +       [8] = {15, 625000},
> +       [9] = {7, 813000},
> +       [10] = {3, 906000}
> +};
> +
> +static const int adxl355_hpf_3db_multipliers[] = {
> +       0,
> +       247000,
> +       62084,
> +       15545,
> +       3862,
> +       954,
> +       238
> +};
> +
> +struct adxl355_data {
> +       struct regmap *regmap;
> +       struct device *dev;
> +       struct mutex lock; /* lock to protect op_mode */
> +       enum adxl355_op_mode op_mode;
> +       enum adxl355_odr odr;
> +       enum adxl355_hpf_3db hpf_3db;
> +       int x_calibbias;
> +       int y_calibbias;
> +       int z_calibbias;
> +       int adxl355_hpf_3db_table[7][2];
> +};
> +
> +static int adxl355_set_op_mode(struct adxl355_data *data,
> +                              enum adxl355_op_mode op_mode)
> +{
> +       int ret;
> +
> +       if (data->op_mode == op_mode)
> +               return 0;
> +
> +       ret = regmap_update_bits(data->regmap, ADXL355_POWER_CTL,
> +                                ADXL355_POWER_CTL_MODE_MSK, op_mode);
> +       if (ret < 0)
> +               return ret;
> +
> +       data->op_mode = op_mode;
> +
> +       return ret;
> +}
> +
> +static void adxl355_fill_3db_frequency_table(struct adxl355_data *data)
> +{
> +       int i;
> +       u64 rem;
> +       u64 div;
> +       u32 multiplier;
> +       u64 odr = mul_u64_u32_shr(adxl355_odr_table[data->odr][0], 1000000, 0) +
> +                                       adxl355_odr_table[data->odr][1];
> +
> +       for (i = 0; i < ARRAY_SIZE(adxl355_hpf_3db_multipliers); i++) {
> +               multiplier = adxl355_hpf_3db_multipliers[i];
> +               div = div64_u64_rem(mul_u64_u32_shr(odr, multiplier, 0),
> +                                   100000000000000UL, &rem);
> +
> +               data->adxl355_hpf_3db_table[i][0] = div;
> +               data->adxl355_hpf_3db_table[i][1] = div_u64(rem, 100000000);
> +       }
> +}
> +
> +static int adxl355_setup(struct adxl355_data *data)
> +{
> +       unsigned int regval;
> +       int ret;
> +
> +       ret = regmap_read(data->regmap, ADXL355_DEVID_AD, &regval);
> +       if (ret < 0)
> +               return ret;
> +
> +       if (regval != ADXL355_DEVID_AD_VAL) {
> +               dev_err(data->dev, "Invalid ADI ID 0x%02x\n", regval);
> +               return -ENODEV;
> +       }
> +
> +       ret = regmap_read(data->regmap, ADXL355_DEVID_MST, &regval);
> +       if (ret < 0)
> +               return ret;
> +
> +       if (regval != ADXL355_DEVID_MST_VAL) {
> +               dev_err(data->dev, "Invalid MEMS ID 0x%02x\n", regval);
> +               return -ENODEV;
> +       }
> +
> +       ret = regmap_read(data->regmap, ADXL355_PARTID, &regval);
> +       if (ret < 0)
> +               return ret;
> +
> +       if (regval != ADXL355_PARTID_VAL) {
> +               dev_err(data->dev, "Invalid DEV ID 0x%02x\n", regval);
> +               return -ENODEV;
> +       }
> +
> +       /*
> +        * Perform a software reset to make sure the device is in a consistent
> +        * state after start up.
> +        */
> +       ret = regmap_write(data->regmap, ADXL355_RESET, ADXL355_RESET_CODE);
> +       if (ret < 0)
> +               return ret;
> +
> +       adxl355_fill_3db_frequency_table(data);
> +
> +       return adxl355_set_op_mode(data, ADXL355_MEASUREMENT);
> +}
> +
> +static int adxl355_get_temp_data(struct adxl355_data *data,
> +                                u8 addr, __be16 *out)
> +{
> +       return regmap_bulk_read(data->regmap, addr, out, sizeof(*out));
> +}
> +
> +static int adxl355_read_axis(struct adxl355_data *data, u8 addr)
> +{
> +       __be32 regval;
> +       int ret;
> +
> +       ret = regmap_bulk_read(data->regmap, addr, &regval, 3);
> +       if (ret < 0)
> +               return ret;
> +
> +       return be32_to_cpu(regval) >> 8;
> +}
> +
> +static int adxl355_find_match(const int (*freq_tbl)[2], const int n,
> +                             const int val, const int val2)
> +{
> +       int i;
> +
> +       for (i = 0; i < n; i++) {
> +               if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2)
> +                       return i;
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +static int adxl355_set_odr(struct adxl355_data *data,
> +                          enum adxl355_odr odr)
> +{
> +       int ret = 0;
> +
> +       mutex_lock(&data->lock);
> +
> +       if (data->odr == odr)
> +               goto out_unlock;
> +
> +       ret = adxl355_set_op_mode(data, ADXL355_STANDBY);
> +       if (ret < 0)
> +               goto out_unlock;
> +
> +       ret = regmap_update_bits(data->regmap, ADXL355_FILTER,
> +                                ADXL355_FILTER_ODR_MSK,
> +                                ADXL355_FILTER_ODR_MODE(odr));
> +       if (!ret) {
> +               data->odr = odr;
> +               adxl355_fill_3db_frequency_table(data);
> +       }
> +
> +out_unlock:
> +       ret = adxl355_set_op_mode(data, ADXL355_MEASUREMENT);
> +       mutex_unlock(&data->lock);
> +       return ret;
> +}
> +
> +static int adxl355_set_hpf_3db(struct adxl355_data *data,
> +                              enum adxl355_hpf_3db hpf)
> +{
> +       int ret = 0;
> +
> +       mutex_lock(&data->lock);
> +
> +       if (data->hpf_3db == hpf)
> +               goto out_unlock;
> +
> +       ret = adxl355_set_op_mode(data, ADXL355_STANDBY);
> +       if (ret < 0)
> +               goto out_unlock;
> +
> +       ret = regmap_update_bits(data->regmap, ADXL355_FILTER,
> +                                ADXL355_FILTER_HPF_MSK,
> +                                ADXL355_FILTER_HPF_MODE(hpf));
> +       if (!ret)
> +               data->hpf_3db = hpf;
> +
> +out_unlock:
> +       ret = adxl355_set_op_mode(data, ADXL355_MEASUREMENT);
> +       mutex_unlock(&data->lock);
> +       return ret;
> +}
> +
> +static int adxl355_set_calibbias(struct adxl355_data *data,
> +                                int scan_index, int calibbias)
> +{
> +       int ret = 0;
> +       __be16 reg = cpu_to_be16(calibbias);
> +
> +       mutex_lock(&data->lock);
> +
> +       ret = adxl355_set_op_mode(data, ADXL355_STANDBY);
> +       if (ret < 0)
> +               goto out_unlock;
> +
> +       switch (scan_index) {
> +       case 0:
> +               ret = regmap_bulk_write(data->regmap, ADXL355_OFFSET_X_H,
> +                                       &reg, 2);
> +               if (ret < 0)
> +                       goto out_unlock;
> +               data->x_calibbias = calibbias;
> +               break;
> +       case 1:
> +               ret = regmap_bulk_write(data->regmap, ADXL355_OFFSET_Y_H,
> +                                       &reg, 2);
> +               if (ret < 0)
> +                       goto out_unlock;
> +               data->y_calibbias = calibbias;
> +               break;
> +       case 2:
> +               ret = regmap_bulk_write(data->regmap, ADXL355_OFFSET_Z_H,
> +                                       &reg, 2);
> +               if (ret < 0)
> +                       goto out_unlock;
> +               data->z_calibbias = calibbias;
> +               break;
> +       default:
> +               ret = -EINVAL;
> +               break;
> +       }
> +
> +out_unlock:
> +       ret = adxl355_set_op_mode(data, ADXL355_MEASUREMENT);
> +       mutex_unlock(&data->lock);
> +       return ret;
> +}
> +
> +static int adxl355_read_raw(struct iio_dev *indio_dev,
> +                           struct iio_chan_spec const *chan,
> +                           int *val, int *val2, long mask)
> +{
> +       struct adxl355_data *data = iio_priv(indio_dev);
> +       int ret;
> +       __be16 out;
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_RAW:
> +               switch (chan->type) {
> +               case IIO_TEMP:
> +                       ret = adxl355_get_temp_data(data, chan->address, &out);
> +                       if (ret < 0)
> +                               return ret;
> +                       *val = be16_to_cpu(out);
> +
> +                       return IIO_VAL_INT;
> +               case IIO_ACCEL:
> +                       ret = adxl355_read_axis(data, chan->address);
> +                       if (ret < 0)
> +                               return ret;
> +                       *val = sign_extend32(ret >> (chan->scan_type.shift),
> +                                            chan->scan_type.realbits - 1);
> +                       return IIO_VAL_INT;
> +               default:
> +                       return -EINVAL;
> +               }
> +
> +       case IIO_CHAN_INFO_SCALE:
> +               switch (chan->type) {
> +               case IIO_TEMP:
> +                       *val = TEMP_SCALE_VAL;
> +                       *val2 = TEMP_SCALE_VAL2;
> +                       return IIO_VAL_INT_PLUS_MICRO;
> +               case IIO_ACCEL:
> +                       *val = 0;
> +                       *val2 = ADXL355_NSCALE;
> +                       return IIO_VAL_INT_PLUS_NANO;
> +               default:
> +                       return -EINVAL;
> +               }
> +       case IIO_CHAN_INFO_OFFSET:
> +               *val = TEMP_OFFSET_VAL;
> +               *val2 = TEMP_OFFSET_VAL2;
> +               return IIO_VAL_INT_PLUS_MICRO;
> +       case IIO_CHAN_INFO_CALIBBIAS:
> +               if (chan->scan_index == 0)
> +                       *val = data->x_calibbias;
> +               else if (chan->scan_index == 1)
> +                       *val = data->y_calibbias;
> +               else
> +                       *val = data->z_calibbias;
> +               *val = sign_extend32(*val, 15);
> +               return IIO_VAL_INT;
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               *val = adxl355_odr_table[data->odr][0];
> +               *val2 = adxl355_odr_table[data->odr][1];
> +               return IIO_VAL_INT_PLUS_MICRO;
> +       case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
> +               *val = data->adxl355_hpf_3db_table[data->hpf_3db][0];
> +               *val2 = data->adxl355_hpf_3db_table[data->hpf_3db][1];
> +               return IIO_VAL_INT_PLUS_MICRO;
> +       }
> +       return -EINVAL;
> +}
> +
> +static int adxl355_write_raw(struct iio_dev *indio_dev,
> +                            struct iio_chan_spec const *chan,
> +                            int val, int val2, long mask)
> +{
> +       struct adxl355_data *data = iio_priv(indio_dev);
> +       int odr_idx, hpf_idx, calibbias;
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               odr_idx = adxl355_find_match(adxl355_odr_table,
> +                                            ARRAY_SIZE(adxl355_odr_table),
> +                                            val, val2);
> +               if (odr_idx < 0)
> +                       return odr_idx;
> +
> +               return adxl355_set_odr(data, odr_idx);
> +       case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
> +               hpf_idx = adxl355_find_match(data->adxl355_hpf_3db_table,
> +                                       ARRAY_SIZE(data->adxl355_hpf_3db_table),
> +                                            val, val2);
> +               if (hpf_idx < 0)
> +                       return hpf_idx;
> +
> +               return adxl355_set_hpf_3db(data, hpf_idx);
> +       case IIO_CHAN_INFO_CALIBBIAS:
> +               calibbias = clamp_t(int, val, S16_MIN, S16_MAX);
> +
> +               return adxl355_set_calibbias(data, chan->scan_index, calibbias);
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static int adxl355_read_avail(struct iio_dev *indio_dev,
> +                             struct iio_chan_spec const *chan,
> +                             const int **vals, int *type, int *length,
> +                             long mask)
> +{
> +       struct adxl355_data *data = iio_priv(indio_dev);
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               *vals = (const int *)adxl355_odr_table;
> +               *type = IIO_VAL_INT_PLUS_MICRO;
> +               /* Values are stored in a 2D matrix */
> +               *length = ARRAY_SIZE(adxl355_odr_table) * 2;
> +
> +               return IIO_AVAIL_LIST;
> +       case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
> +               *vals = (const int *)(data->adxl355_hpf_3db_table);
> +               *type = IIO_VAL_INT_PLUS_MICRO;
> +               /* Values are stored in a 2D matrix */
> +               *length = ARRAY_SIZE(data->adxl355_hpf_3db_table) * 2;
> +
> +               return IIO_AVAIL_LIST;
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static const unsigned long adxl355_avail_scan_masks[] = {
> +       GENMASK(3, 0),
> +       0
> +};
> +
> +static const struct iio_info adxl355_info = {
> +       .read_raw       = adxl355_read_raw,
> +       .write_raw      = adxl355_write_raw,
> +       .read_avail     = &adxl355_read_avail
> +};
> +
> +#define ADXL355_ACCEL_CHANNEL(index, reg, axis) {                      \
> +       .type = IIO_ACCEL,                                              \
> +       .address = reg,                                                 \
> +       .modified = 1,                                                  \
> +       .channel2 = IIO_MOD_##axis,                                     \
> +       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
> +                             BIT(IIO_CHAN_INFO_CALIBBIAS),             \
> +       .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
> +                                   BIT(IIO_CHAN_INFO_SAMP_FREQ) |      \
> +               BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),      \
> +       .info_mask_shared_by_type_available =                           \
> +               BIT(IIO_CHAN_INFO_SAMP_FREQ) |                          \
> +               BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),      \
> +       .scan_index = index,                                            \
> +       .scan_type = {                                                  \
> +               .sign = 's',                                            \
> +               .realbits = 20,                                         \
> +               .storagebits = 32,                                      \
> +               .shift = 4,                                             \
> +               .endianness = IIO_BE,                                   \
> +       }                                                               \
> +}
> +
> +static const struct iio_chan_spec adxl355_channels[] = {
> +       ADXL355_ACCEL_CHANNEL(0, ADXL355_XDATA3, X),
> +       ADXL355_ACCEL_CHANNEL(1, ADXL355_YDATA3, Y),
> +       ADXL355_ACCEL_CHANNEL(2, ADXL355_ZDATA3, Z),
> +       {
> +               .type = IIO_TEMP,
> +               .address = ADXL355_TEMP2,
> +               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +                                     BIT(IIO_CHAN_INFO_SCALE) |
> +                                     BIT(IIO_CHAN_INFO_OFFSET),
> +               .scan_index = 3,
> +               .scan_type = {
> +                       .sign = 's',
> +                       .realbits = 12,
> +                       .storagebits = 16,
> +                       .endianness = IIO_BE,
> +               },
> +       }
> +};
> +
> +int adxl355_core_probe(struct device *dev, struct regmap *regmap,
> +                      const char *name)
> +{
> +       struct adxl355_data *data;
> +       struct iio_dev *indio_dev;
> +       int ret;
> +
> +       indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +       if (!indio_dev)
> +               return -ENOMEM;
> +
> +       data = iio_priv(indio_dev);
> +       data->regmap = regmap;
> +       data->dev = dev;
> +       data->op_mode = ADXL355_STANDBY;
> +       mutex_init(&data->lock);
> +
> +       indio_dev->name = name;
> +       indio_dev->info = &adxl355_info;
> +       indio_dev->modes = INDIO_DIRECT_MODE;
> +       indio_dev->channels = adxl355_channels;
> +       indio_dev->num_channels = ARRAY_SIZE(adxl355_channels);
> +       indio_dev->available_scan_masks = adxl355_avail_scan_masks;
> +
> +       ret = adxl355_setup(data);
> +       if (ret < 0) {
> +               dev_err(dev, "ADXL355 setup failed\n");
> +               return ret;
> +       }
> +
> +       return devm_iio_device_register(dev, indio_dev);
> +}
> +EXPORT_SYMBOL_GPL(adxl355_core_probe);
> +
> +MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
> +MODULE_DESCRIPTION("ADXL355 3-Axis Digital Accelerometer core driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/accel/adxl355_i2c.c b/drivers/iio/accel/adxl355_i2c.c
> new file mode 100644
> index 000000000..6b84d8df2
> --- /dev/null
> +++ b/drivers/iio/accel/adxl355_i2c.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ADXL355 3-Axis Digital Accelerometer I2C driver
> + *
> + * Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include "adxl355.h"
> +
> +static const struct regmap_config adxl355_i2c_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +       .max_register = 0x2F,
> +       .rd_table = &adxl355_readable_regs_tbl,
> +       .wr_table = &adxl355_writeable_regs_tbl
> +};
> +
> +static int adxl355_i2c_probe(struct i2c_client *client)
> +{
> +       struct regmap *regmap;
> +
> +       regmap = devm_regmap_init_i2c(client, &adxl355_i2c_regmap_config);
> +       if (IS_ERR(regmap)) {
> +               dev_err(&client->dev, "Error initializing i2c regmap: %ld\n",
> +                       PTR_ERR(regmap));
> +               return PTR_ERR(regmap);
> +       }
> +
> +       return adxl355_core_probe(&client->dev, regmap, client->name);
> +}
> +
> +static const struct i2c_device_id adxl355_i2c_id[] = {
> +       { "adxl355", 0 },
> +       { }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, adxl355_i2c_id);
> +
> +static const struct of_device_id adxl355_of_match[] = {
> +       { .compatible = "adi,adxl355" },
> +       { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, adxl355_of_match);
> +
> +static struct i2c_driver adxl355_i2c_driver = {
> +       .driver = {
> +               .name   = "adxl355_i2c",
> +               .of_match_table = adxl355_of_match,
> +       },
> +       .probe_new      = adxl355_i2c_probe,
> +       .id_table       = adxl355_i2c_id,
> +};
> +
> +module_i2c_driver(adxl355_i2c_driver);
> +
> +MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
> +MODULE_DESCRIPTION("ADXL355 3-Axis Digital Accelerometer I2C driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/accel/adxl355_spi.c b/drivers/iio/accel/adxl355_spi.c
> new file mode 100644
> index 000000000..108d1b308
> --- /dev/null
> +++ b/drivers/iio/accel/adxl355_spi.c
> @@ -0,0 +1,66 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ADXL355 3-Axis Digital Accelerometer SPI driver
> + *
> + * Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.h>
> +
> +#include "adxl355.h"
> +
> +static const struct regmap_config adxl355_spi_regmap_config = {
> +       .reg_bits = 7,
> +       .pad_bits = 1,
> +       .val_bits = 8,
> +       .read_flag_mask = BIT(0),
> +       .max_register = 0x2F,
> +       .rd_table = &adxl355_readable_regs_tbl,
> +       .wr_table = &adxl355_writeable_regs_tbl
> +};
> +
> +static int adxl355_spi_probe(struct spi_device *spi)
> +{
> +       const struct spi_device_id *id = spi_get_device_id(spi);
> +       struct regmap *regmap;
> +
> +       regmap = devm_regmap_init_spi(spi, &adxl355_spi_regmap_config);
> +       if (IS_ERR(regmap)) {
> +               dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
> +                       PTR_ERR(regmap));
> +               return PTR_ERR(regmap);
> +       }
> +
> +       return adxl355_core_probe(&spi->dev, regmap, id->name);
> +}
> +
> +static const struct spi_device_id adxl355_spi_id[] = {
> +       { "adxl355", 0 },
> +       { }
> +};
> +
> +MODULE_DEVICE_TABLE(spi, adxl355_spi_id);
> +
> +static const struct of_device_id adxl355_of_match[] = {
> +       { .compatible = "adi,adxl355" },
> +       { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, adxl355_of_match);
> +
> +static struct spi_driver adxl355_spi_driver = {
> +       .driver = {
> +               .name   = "adxl355_spi",
> +               .of_match_table = adxl355_of_match,
> +       },
> +       .probe          = adxl355_spi_probe,
> +       .id_table       = adxl355_spi_id,
> +};
> +
> +module_spi_driver(adxl355_spi_driver);
> +
> +MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
> +MODULE_DESCRIPTION("ADXL355 3-Axis Digital Accelerometer SPI driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.30.1
>