Re: [PATCH 2/2] iio: accel: Add driver support for ADXL355

From: Alexandru Ardelean
Date: Tue Jul 20 2021 - 03:05:25 EST

On Mon, Jul 19, 2021 at 8:06 PM Puranjay Mohan <puranjay12@xxxxxxxxx> wrote:
>
> .
>
> On Mon, Jul 19, 2021 at 5:35 PM Alexandru Ardelean
> <ardeleanalex@xxxxxxxxx> wrote:
> >
> > (
> >
> > On Sun, Jul 18, 2021 at 9:01 PM Puranjay Mohan <puranjay12@xxxxxxxxx> 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.
> > >
> >
> > Hey,
> >
> > This looks pretty good.
> > A few comments inline.
> >
> > > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/adxl354_adxl355.pdf
> > > Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> > > ---
> > > MAINTAINERS | 7 +
> > > drivers/iio/accel/Kconfig | 29 ++
> > > drivers/iio/accel/Makefile | 3 +
> > > drivers/iio/accel/adxl355.h | 83 +++++
> > > drivers/iio/accel/adxl355_core.c | 544 +++++++++++++++++++++++++++++++
> > > drivers/iio/accel/adxl355_i2c.c | 63 ++++
> > > drivers/iio/accel/adxl355_spi.c | 66 ++++
> > > 7 files changed, 795 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@xxxxxxxxx>
> > > +L: linux-iio@xxxxxxxxxxxxxxx
> > > +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@xxxxxxxxxx>
> > > 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..e52c294d8
> > > --- /dev/null
> > > +++ b/drivers/iio/accel/adxl355.h
> > > @@ -0,0 +1,83 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +/*
> > > + * ADXL355 3-Axis Digital Accelerometer
> > > + *
> > > + * Copyright (c) 2021 Puranjay Mohan <puranjay12@xxxxxxxxx>
> > > + */
> > > +
> > > +#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_range adxl355_read_reg_range[];
> > > +
> > > +extern const struct regmap_access_table adxl355_readable_regs_tbl;
> > > +
> > > +extern const struct regmap_range adxl355_write_reg_range[];
> > > +
> > > +extern const struct regmap_access_table adxl355_writeable_regs_tbl;
> > > +
> > > +int adxl355_core_probe(struct device *dev, struct regmap *regmap,
> > > + const char *name);
> >
> > I would put most all these definitions in the core file, since they
> > are mostly used there.
> > I'd leave only what's shared between files here.
> > i.e. adxl355_core_probe() and adxl355_{read,write}able_regs_tbl here
> > Of course, that's my preference. The way it is done here is a fine as well.
> >
> I just wanted to keep the defines in the header file to keep the core
> file clean. I will move them if it is a requirement.
> >
> > > +#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..5fdd3c73e
> > > --- /dev/null
> > > +++ b/drivers/iio/accel/adxl355_core.c
> > > @@ -0,0 +1,544 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * ADXL355 3-Axis Digital Accelerometer IIO core driver
> > > + *
> > > + * Copyright (c) 2021 Puranjay Mohan <puranjay12@xxxxxxxxx>
> > > + *
> > > + * 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"
> > > +
> > > +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)
> > > +};
> > > +EXPORT_SYMBOL_GPL(adxl355_read_reg_range);
> >
> > It does not look like this regmap definition is used outside of the
> > core file, so maybe just keep it private/static for this file?
>
> Yes, I should have kept these private, will change them in the next version.
> >
> > > +
> > > +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);
> > > +
> > > +const struct regmap_range adxl355_write_reg_range[] = {
> > > + regmap_reg_range(ADXL355_OFFSET_X_H, ADXL355_RESET)
> > > +};
> > > +EXPORT_SYMBOL_GPL(adxl355_write_reg_range);
> > > +
> >
> > This doesn't look like it's used between files, so maybe keep it private?
>
> Will change in v1
>
> >
> > > +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 int adxl355_hpf_3db_table[7][2] = {0};
> >
> > Maybe make this const as well?
>
> This struct can't be made const as it is filled up at runtime.
> This devices' supported 3d frequencies are dependant on the chosen
> sampling frequency, so this table gets updated every time the sampling
> frequency is changed.
> It is first filled up by a call to adxl355_fill_3db_frequency_table()
> in adxl355_setup(). Whenever the sampling frequency is updated, the
> adxl355_fill_3db_frequency_table() is called to refill the table.

This doesn't work well in setups where there would be more than 1
ADXL355 device instance.
If one device updates the table, it affects any other ADXL355 device[s].
Naturally, what this means, is that this table should be moved on the
adxl355_data struct, to be able to support this.

Generally, what I've noticed [with C coding patterns and it's more
true in kernel drivers] is that non-const globals are rarely a good
idea.
The cases where non-const globals seem to be useful are with global
lists to track certain resources [e.g. list of devices instantiated by
a driver].
But a lot of these global lists tend to be implemented in kernel
frameworks, so it's even more rare that non-const globals are found in
drivers.

>
> >
> > > +
> > > +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;
> > > +};
> > > +
> > > +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);
> > > +
> > > + adxl355_hpf_3db_table[i][0] = div;
> > > + 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)
> > > + break;
> > > + *val = be16_to_cpu(out);
> > > + ret = IIO_VAL_INT;
> > > + break;
> > > +
> > > + case IIO_ACCEL:
> > > + ret = adxl355_read_axis(data, chan->address);
> > > + if (ret < 0)
> > > + break;
> > > + *val = sign_extend32(ret >> (chan->scan_type.shift),
> > > + chan->scan_type.realbits - 1);
> > > + ret = IIO_VAL_INT;
> > > + break;
> > > +
> > > + default:
> > > + ret = -EINVAL;
> > > + break;
> > > + }
> > > +
> > > + return ret;
> > > + 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 = adxl355_hpf_3db_table[data->hpf_3db][0];
> > > + *val2 = 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, ret;
> > > +
> > > + 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(adxl355_hpf_3db_table,
> > > + ARRAY_SIZE(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);
> > > + ret = adxl355_set_calibbias(data, chan->scan_index, calibbias);
> > > +
> > > + return ret;
> >
> > return adxl355_set_calibbias(); directly
>
> will change in v1.
> >
> >
> > > + 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)
> > > +{
> > > + 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 *)adxl355_hpf_3db_table;
> > > + *type = IIO_VAL_INT_PLUS_MICRO;
> > > + /* Values are stored in a 2D matrix */
> > > + *length = ARRAY_SIZE(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->dev.parent = dev;
> >
> > This parent assignment can be removed.
> > It's done in devm_iio_device_alloc()
>
> will change in v1.
> >
> > > + 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@xxxxxxxxx>");
> > > +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..1c9764129
> > > --- /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@xxxxxxxxx>
> > > + */
> > > +
> > > +#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" },
> > > + { },
> >
> > Comma can be removed.
> > It's a null-terminator.
> will change in v1.
> >
> > > +};
> > > +
> > > +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@xxxxxxxxx>");
> > > +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..ae02cbfad
> > > --- /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@xxxxxxxxx>
> > > + */
> > > +
> > > +#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" },
> > > + { },
> >
> > Comma can be removed.
> >
> > > +};
> > > +
> > > +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@xxxxxxxxx>");
> > > +MODULE_DESCRIPTION("ADXL355 3-Axis Digital Accelerometer SPI driver");
> > > +MODULE_LICENSE("GPL v2");
> > > --
> > > 2.30.1
> > >
>
>
>
> --
> Thanks and Regards
>
> Yours Truly,
>
> Puranjay Mohan