iio: gyro: add core driver for fxas21002c

Add core support for the NXP fxas21002c Tri-axis gyroscope,
using the iio subsystem. It supports PM operations, axis reading,
temperature, scale factor of the axis, high pass and low pass
filtering, and sampling frequency selection.

It will have extras modules to support the communication over i2c and
spi.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/gyro/Kconfig

@@ -73,6 +73,17 @@ config BMG160_SPI
 	tristate
 	select REGMAP_SPI
 
+config FXAS21002C
+       tristate "NXP FXAS21002C Gyro Sensor"
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
+       help
+         Say yes here to build support for NXP FXAS21002C Tri-axis Gyro
+         Sensor driver connected via I2C or SPI.
+
+         This driver can also be built as a module.  If so, the module
+         will be called fxas21002c_i2c or fxas21002c_spi.
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER

drivers/iio/gyro/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_ADXRS450) += adxrs450.o
 obj-$(CONFIG_BMG160) += bmg160_core.o
 obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o
 obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
+obj-$(CONFIG_FXAS21002C) += fxas21002c_core.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 

drivers/iio/gyro/fxas21002c.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Driver for NXP FXAS21002C Gyroscope - Header
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#ifndef FXAS21002C_H_
+#define FXAS21002C_H_
+
+#include <linux/regmap.h>
+
+#define FXAS21002C_REG_STATUS		0x00
+#define FXAS21002C_REG_OUT_X_MSB	0x01
+#define FXAS21002C_REG_OUT_X_LSB	0x02
+#define FXAS21002C_REG_OUT_Y_MSB	0x03
+#define FXAS21002C_REG_OUT_Y_LSB	0x04
+#define FXAS21002C_REG_OUT_Z_MSB	0x05
+#define FXAS21002C_REG_OUT_Z_LSB	0x06
+#define FXAS21002C_REG_DR_STATUS	0x07
+#define FXAS21002C_REG_F_STATUS		0x08
+#define FXAS21002C_REG_F_SETUP		0x09
+#define FXAS21002C_REG_F_EVENT		0x0A
+#define FXAS21002C_REG_INT_SRC_FLAG	0x0B
+#define FXAS21002C_REG_WHO_AM_I		0x0C
+#define FXAS21002C_REG_CTRL0		0x0D
+#define FXAS21002C_REG_RT_CFG		0x0E
+#define FXAS21002C_REG_RT_SRC		0x0F
+#define FXAS21002C_REG_RT_THS		0x10
+#define FXAS21002C_REG_RT_COUNT		0x11
+#define FXAS21002C_REG_TEMP		0x12
+#define FXAS21002C_REG_CTRL1		0x13
+#define FXAS21002C_REG_CTRL2		0x14
+#define FXAS21002C_REG_CTRL3		0x15
+
+enum fxas21002c_fields {
+	F_DR_STATUS,
+	F_OUT_X_MSB,
+	F_OUT_X_LSB,
+	F_OUT_Y_MSB,
+	F_OUT_Y_LSB,
+	F_OUT_Z_MSB,
+	F_OUT_Z_LSB,
+	/* DR_STATUS */
+	F_ZYX_OW, F_Z_OW, F_Y_OW, F_X_OW, F_ZYX_DR, F_Z_DR, F_Y_DR, F_X_DR,
+	/* F_STATUS */
+	F_OVF, F_WMKF, F_CNT,
+	/* F_SETUP */
+	F_MODE, F_WMRK,
+	/* F_EVENT */
+	F_EVENT, FE_TIME,
+	/* INT_SOURCE_FLAG */
+	F_BOOTEND, F_SRC_FIFO, F_SRC_RT, F_SRC_DRDY,
+	/* WHO_AM_I */
+	F_WHO_AM_I,
+	/* CTRL_REG0 */
+	F_BW, F_SPIW, F_SEL, F_HPF_EN, F_FS,
+	/* RT_CFG */
+	F_ELE, F_ZTEFE, F_YTEFE, F_XTEFE,
+	/* RT_SRC */
+	F_EA, F_ZRT, F_ZRT_POL, F_YRT, F_YRT_POL, F_XRT, F_XRT_POL,
+	/* RT_THS */
+	F_DBCNTM, F_THS,
+	/* RT_COUNT */
+	F_RT_COUNT,
+	/* TEMP */
+	F_TEMP,
+	/* CTRL_REG1 */
+	F_RST, F_ST, F_DR, F_ACTIVE, F_READY,
+	/* CTRL_REG2 */
+	F_INT_CFG_FIFO, F_INT_EN_FIFO, F_INT_CFG_RT, F_INT_EN_RT,
+	F_INT_CFG_DRDY, F_INT_EN_DRDY, F_IPOL, F_PP_OD,
+	/* CTRL_REG3 */
+	F_WRAPTOONE, F_EXTCTRLEN, F_FS_DOUBLE,
+	/* MAX FIELDS */
+	F_MAX_FIELDS,
+};
+
+static const struct reg_field fxas21002c_reg_fields[] = {
+	[F_DR_STATUS]		= REG_FIELD(FXAS21002C_REG_STATUS, 0, 7),
+	[F_OUT_X_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_X_MSB, 0, 7),
+	[F_OUT_X_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_X_LSB, 0, 7),
+	[F_OUT_Y_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_Y_MSB, 0, 7),
+	[F_OUT_Y_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_Y_LSB, 0, 7),
+	[F_OUT_Z_MSB]		= REG_FIELD(FXAS21002C_REG_OUT_Z_MSB, 0, 7),
+	[F_OUT_Z_LSB]		= REG_FIELD(FXAS21002C_REG_OUT_Z_LSB, 0, 7),
+	[F_ZYX_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 7, 7),
+	[F_Z_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 6, 6),
+	[F_Y_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 5, 5),
+	[F_X_OW]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 4, 4),
+	[F_ZYX_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 3, 3),
+	[F_Z_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 2, 2),
+	[F_Y_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 1, 1),
+	[F_X_DR]		= REG_FIELD(FXAS21002C_REG_DR_STATUS, 0, 0),
+	[F_OVF]			= REG_FIELD(FXAS21002C_REG_F_STATUS, 7, 7),
+	[F_WMKF]		= REG_FIELD(FXAS21002C_REG_F_STATUS, 6, 6),
+	[F_CNT]			= REG_FIELD(FXAS21002C_REG_F_STATUS, 0, 5),
+	[F_MODE]		= REG_FIELD(FXAS21002C_REG_F_SETUP, 6, 7),
+	[F_WMRK]		= REG_FIELD(FXAS21002C_REG_F_SETUP, 0, 5),
+	[F_EVENT]		= REG_FIELD(FXAS21002C_REG_F_EVENT, 5, 5),
+	[FE_TIME]		= REG_FIELD(FXAS21002C_REG_F_EVENT, 0, 4),
+	[F_BOOTEND]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 3, 3),
+	[F_SRC_FIFO]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 2, 2),
+	[F_SRC_RT]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 1, 1),
+	[F_SRC_DRDY]		= REG_FIELD(FXAS21002C_REG_INT_SRC_FLAG, 0, 0),
+	[F_WHO_AM_I]		= REG_FIELD(FXAS21002C_REG_WHO_AM_I, 0, 7),
+	[F_BW]			= REG_FIELD(FXAS21002C_REG_CTRL0, 6, 7),
+	[F_SPIW]		= REG_FIELD(FXAS21002C_REG_CTRL0, 5, 5),
+	[F_SEL]			= REG_FIELD(FXAS21002C_REG_CTRL0, 3, 4),
+	[F_HPF_EN]		= REG_FIELD(FXAS21002C_REG_CTRL0, 2, 2),
+	[F_FS]			= REG_FIELD(FXAS21002C_REG_CTRL0, 0, 1),
+	[F_ELE]			= REG_FIELD(FXAS21002C_REG_RT_CFG, 3, 3),
+	[F_ZTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 2, 2),
+	[F_YTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 1, 1),
+	[F_XTEFE]		= REG_FIELD(FXAS21002C_REG_RT_CFG, 0, 0),
+	[F_EA]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 6, 6),
+	[F_ZRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 5, 5),
+	[F_ZRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 4, 4),
+	[F_YRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 3, 3),
+	[F_YRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 2, 2),
+	[F_XRT]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 1, 1),
+	[F_XRT_POL]		= REG_FIELD(FXAS21002C_REG_RT_SRC, 0, 0),
+	[F_DBCNTM]		= REG_FIELD(FXAS21002C_REG_RT_THS, 7, 7),
+	[F_THS]			= REG_FIELD(FXAS21002C_REG_RT_SRC, 0, 6),
+	[F_RT_COUNT]		= REG_FIELD(FXAS21002C_REG_RT_COUNT, 0, 7),
+	[F_TEMP]		= REG_FIELD(FXAS21002C_REG_TEMP, 0, 7),
+	[F_RST]			= REG_FIELD(FXAS21002C_REG_CTRL1, 6, 6),
+	[F_ST]			= REG_FIELD(FXAS21002C_REG_CTRL1, 5, 5),
+	[F_DR]			= REG_FIELD(FXAS21002C_REG_CTRL1, 2, 4),
+	[F_ACTIVE]		= REG_FIELD(FXAS21002C_REG_CTRL1, 1, 1),
+	[F_READY]		= REG_FIELD(FXAS21002C_REG_CTRL1, 0, 0),
+	[F_INT_CFG_FIFO]	= REG_FIELD(FXAS21002C_REG_CTRL2, 7, 7),
+	[F_INT_EN_FIFO]		= REG_FIELD(FXAS21002C_REG_CTRL2, 6, 6),
+	[F_INT_CFG_RT]		= REG_FIELD(FXAS21002C_REG_CTRL2, 5, 5),
+	[F_INT_EN_RT]		= REG_FIELD(FXAS21002C_REG_CTRL2, 4, 4),
+	[F_INT_CFG_DRDY]	= REG_FIELD(FXAS21002C_REG_CTRL2, 3, 3),
+	[F_INT_EN_DRDY]		= REG_FIELD(FXAS21002C_REG_CTRL2, 2, 2),
+	[F_IPOL]		= REG_FIELD(FXAS21002C_REG_CTRL2, 1, 1),
+	[F_PP_OD]		= REG_FIELD(FXAS21002C_REG_CTRL2, 0, 0),
+	[F_WRAPTOONE]		= REG_FIELD(FXAS21002C_REG_CTRL3, 3, 3),
+	[F_EXTCTRLEN]		= REG_FIELD(FXAS21002C_REG_CTRL3, 2, 2),
+	[F_FS_DOUBLE]		= REG_FIELD(FXAS21002C_REG_CTRL3, 0, 0),
+};
+
+extern const struct dev_pm_ops fxas21002c_pm_ops;
+
+int fxas21002c_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			  const char *name);
+void fxas21002c_core_remove(struct device *dev);
+#endif

drivers/iio/gyro/fxas21002c_core.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for NXP FXAS21002C Gyroscope - Core
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include "fxas21002c.h"
+
+#define FXAS21002C_CHIP_ID_1	0xD6
+#define FXAS21002C_CHIP_ID_2	0xD7
+
+enum fxas21002c_mode_state {
+	FXAS21002C_MODE_STANDBY,
+	FXAS21002C_MODE_READY,
+	FXAS21002C_MODE_ACTIVE,
+};
+
+#define FXAS21002C_STANDBY_ACTIVE_TIME_MS	62
+#define FXAS21002C_READY_ACTIVE_TIME_MS		7
+
+#define FXAS21002C_ODR_LIST_MAX		10
+
+#define FXAS21002C_SCALE_FRACTIONAL	32
+#define FXAS21002C_RANGE_LIMIT_DOUBLE	2000
+
+#define FXAS21002C_AXIS_TO_REG(axis) (FXAS21002C_REG_OUT_X_MSB + ((axis) * 2))
+
+static const int fxas21002c_odr_values[] = {
+	800, 400, 200, 100, 50, 25, 12, 12
+};
+
+/*
+ * These values are taken from the low-pass filter cutoff frequency calculated
+ * ODR * 0.lpf_values. So, for ODR = 800Hz with a lpf value = 0.32
+ * => LPF cutoff frequency = 800 * 0.32 = 256 Hz
+ */
+static const int fxas21002c_lpf_values[] = {
+	32, 16, 8
+};
+
+/*
+ * These values are taken from the high-pass filter cutoff frequency calculated
+ * ODR * 0.0hpf_values. So, for ODR = 800Hz with a hpf value = 0.018750
+ * => HPF cutoff frequency = 800 * 0.018750 = 15 Hz
+ */
+static const int fxas21002c_hpf_values[] = {
+	18750, 9625, 4875, 2475
+};
+
+static const int fxas21002c_range_values[] = {
+	4000, 2000, 1000, 500, 250
+};
+
+struct fxas21002c_data {
+	u8 chip_id;
+	enum fxas21002c_mode_state mode;
+	enum fxas21002c_mode_state prev_mode;
+
+	struct mutex lock;		/* serialize data access */
+	struct regmap *regmap;
+	struct regmap_field *regmap_fields[F_MAX_FIELDS];
+	struct iio_trigger *dready_trig;
+	s64 timestamp;
+	int irq;
+
+	struct regulator *vdd;
+	struct regulator *vddio;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	s16 buffer[8] ____cacheline_aligned;
+};
+
+enum fxas21002c_channel_index {
+	CHANNEL_SCAN_INDEX_X,
+	CHANNEL_SCAN_INDEX_Y,
+	CHANNEL_SCAN_INDEX_Z,
+	CHANNEL_SCAN_MAX,
+};
+
+static int fxas21002c_odr_hz_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int odr_value_max = ARRAY_SIZE(fxas21002c_odr_values) - 1;
+
+	value = min_t(u8, value, odr_value_max);
+
+	return fxas21002c_odr_values[value];
+}
+
+static int fxas21002c_odr_value_from_hz(struct fxas21002c_data *data,
+					unsigned int hz)
+{
+	int odr_table_size = ARRAY_SIZE(fxas21002c_odr_values);
+	int i;
+
+	for (i = 0; i < odr_table_size; i++)
+		if (fxas21002c_odr_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_lpf_bw_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int lpf_value_max = ARRAY_SIZE(fxas21002c_lpf_values) - 1;
+
+	value = min_t(u8, value, lpf_value_max);
+
+	return fxas21002c_lpf_values[value];
+}
+
+static int fxas21002c_lpf_value_from_bw(struct fxas21002c_data *data,
+					unsigned int hz)
+{
+	int lpf_table_size = ARRAY_SIZE(fxas21002c_lpf_values);
+	int i;
+
+	for (i = 0; i < lpf_table_size; i++)
+		if (fxas21002c_lpf_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_hpf_sel_from_value(struct fxas21002c_data *data, u8 value)
+{
+	int hpf_value_max = ARRAY_SIZE(fxas21002c_hpf_values) - 1;
+
+	value = min_t(u8, value, hpf_value_max);
+
+	return fxas21002c_hpf_values[value];
+}
+
+static int fxas21002c_hpf_value_from_sel(struct fxas21002c_data *data,
+					 unsigned int hz)
+{
+	int hpf_table_size = ARRAY_SIZE(fxas21002c_hpf_values);
+	int i;
+
+	for (i = 0; i < hpf_table_size; i++)
+		if (fxas21002c_hpf_values[i] == hz)
+			return i;
+
+	return -EINVAL;
+}
+
+static int fxas21002c_range_fs_from_value(struct fxas21002c_data *data,
+					  u8 value)
+{
+	int range_value_max = ARRAY_SIZE(fxas21002c_range_values) - 1;
+	unsigned int fs_double;
+	int ret;
+
+	/* We need to check if FS_DOUBLE is enabled to offset the value */
+	ret = regmap_field_read(data->regmap_fields[F_FS_DOUBLE], &fs_double);
+	if (ret < 0)
+		return ret;
+
+	if (!fs_double)
+		value += 1;
+
+	value = min_t(u8, value, range_value_max);
+
+	return fxas21002c_range_values[value];
+}
+
+static int fxas21002c_range_value_from_fs(struct fxas21002c_data *data,
+					  unsigned int range)
+{
+	int range_table_size = ARRAY_SIZE(fxas21002c_range_values);
+	bool found = false;
+	int fs_double = 0;
+	int ret;
+	int i;
+
+	for (i = 0; i < range_table_size; i++)
+		if (fxas21002c_range_values[i] == range) {
+			found = true;
+			break;
+		}
+
+	if (!found)
+		return -EINVAL;
+
+	if (range > FXAS21002C_RANGE_LIMIT_DOUBLE)
+		fs_double = 1;
+
+	ret = regmap_field_write(data->regmap_fields[F_FS_DOUBLE], fs_double);
+	if (ret < 0)
+		return ret;
+
+	return i;
+}
+
+static int fxas21002c_mode_get(struct fxas21002c_data *data)
+{
+	unsigned int active;
+	unsigned int ready;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_ACTIVE], &active);
+	if (ret < 0)
+		return ret;
+	if (active)
+		return FXAS21002C_MODE_ACTIVE;
+
+	ret = regmap_field_read(data->regmap_fields[F_READY], &ready);
+	if (ret < 0)
+		return ret;
+	if (ready)
+		return FXAS21002C_MODE_READY;
+
+	return FXAS21002C_MODE_STANDBY;
+}
+
+static int fxas21002c_mode_set(struct fxas21002c_data *data,
+			       enum fxas21002c_mode_state mode)
+{
+	int ret;
+
+	if (mode == data->mode)
+		return 0;
+
+	if (mode == FXAS21002C_MODE_READY)
+		ret = regmap_field_write(data->regmap_fields[F_READY], 1);
+	else
+		ret = regmap_field_write(data->regmap_fields[F_READY], 0);
+	if (ret < 0)
+		return ret;
+
+	if (mode == FXAS21002C_MODE_ACTIVE)
+		ret = regmap_field_write(data->regmap_fields[F_ACTIVE], 1);
+	else
+		ret = regmap_field_write(data->regmap_fields[F_ACTIVE], 0);
+	if (ret < 0)
+		return ret;
+
+	/* if going to active wait the setup times */
+	if (mode == FXAS21002C_MODE_ACTIVE &&
+	    data->mode == FXAS21002C_MODE_STANDBY)
+		msleep_interruptible(FXAS21002C_STANDBY_ACTIVE_TIME_MS);
+
+	if (data->mode == FXAS21002C_MODE_READY)
+		msleep_interruptible(FXAS21002C_READY_ACTIVE_TIME_MS);
+
+	data->prev_mode = data->mode;
+	data->mode = mode;
+
+	return ret;
+}
+
+static int fxas21002c_write(struct fxas21002c_data *data,
+			    enum fxas21002c_fields field, int bits)
+{
+	int actual_mode;
+	int ret;
+
+	mutex_lock(&data->lock);
+
+	actual_mode = fxas21002c_mode_get(data);
+	if (actual_mode < 0) {
+		ret = actual_mode;
+		goto out_unlock;
+	}
+
+	ret = fxas21002c_mode_set(data, FXAS21002C_MODE_READY);
+	if (ret < 0)
+		goto out_unlock;
+
+	ret = regmap_field_write(data->regmap_fields[field], bits);
+	if (ret < 0)
+		goto out_unlock;
+
+	ret = fxas21002c_mode_set(data, data->prev_mode);
+
+out_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int  fxas21002c_pm_get(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		pm_runtime_put_noidle(dev);
+
+	return ret;
+}
+
+static int  fxas21002c_pm_put(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+
+	pm_runtime_mark_last_busy(dev);
+
+	return pm_runtime_put_autosuspend(dev);
+}
+
+static int fxas21002c_temp_get(struct fxas21002c_data *data, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int temp;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = fxas21002c_pm_get(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = regmap_field_read(data->regmap_fields[F_TEMP], &temp);
+	if (ret < 0) {
+		dev_err(dev, "failed to read temp: %d\n", ret);
+		goto data_unlock;
+	}
+
+	*val = sign_extend32(temp, 7);
+
+	ret = fxas21002c_pm_put(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_axis_get(struct fxas21002c_data *data,
+			       int index, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	__be16 axis_be;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = fxas21002c_pm_get(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = regmap_bulk_read(data->regmap, FXAS21002C_AXIS_TO_REG(index),
+			       &axis_be, sizeof(axis_be));
+	if (ret < 0) {
+		dev_err(dev, "failed to read axis: %d: %d\n", index, ret);
+		goto data_unlock;
+	}
+
+	*val = sign_extend32(be16_to_cpu(axis_be), 15);
+
+	ret = fxas21002c_pm_put(data);
+	if (ret < 0)
+		goto data_unlock;
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_odr_get(struct fxas21002c_data *data, int *odr)
+{
+	unsigned int odr_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_DR], &odr_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*odr = fxas21002c_odr_hz_from_value(data, odr_bits);
+
+	ret = IIO_VAL_INT;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_odr_set(struct fxas21002c_data *data, int odr)
+{
+	int odr_bits;
+
+	odr_bits = fxas21002c_odr_value_from_hz(data, odr);
+	if (odr_bits < 0)
+		return odr_bits;
+
+	return fxas21002c_write(data, F_DR, odr_bits);
+}
+
+static int fxas21002c_lpf_get(struct fxas21002c_data *data, int *val2)
+{
+	unsigned int bw_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_BW], &bw_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*val2 = fxas21002c_lpf_bw_from_value(data, bw_bits) * 10000;
+
+	ret = IIO_VAL_INT_PLUS_MICRO;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_lpf_set(struct fxas21002c_data *data, int bw)
+{
+	int bw_bits;
+	int odr;
+	int ret;
+
+	bw_bits = fxas21002c_lpf_value_from_bw(data, bw);
+	if (bw_bits < 0)
+		return bw_bits;
+
+	/*
+	 * From table 33 of the device spec, for ODR = 25Hz and 12.5 value 0.08
+	 * is not allowed and for ODR = 12.5 value 0.16 is also not allowed
+	 */
+	ret = fxas21002c_odr_get(data, &odr);
+	if (ret < 0)
+		return -EINVAL;
+
+	if ((odr == 25 && bw_bits > 0x01) || (odr == 12 && bw_bits > 0))
+		return -EINVAL;
+
+	return fxas21002c_write(data, F_BW, bw_bits);
+}
+
+static int fxas21002c_hpf_get(struct fxas21002c_data *data, int *val2)
+{
+	unsigned int sel_bits;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_SEL], &sel_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	*val2 = fxas21002c_hpf_sel_from_value(data, sel_bits);
+
+	ret = IIO_VAL_INT_PLUS_MICRO;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_hpf_set(struct fxas21002c_data *data, int sel)
+{
+	int sel_bits;
+
+	sel_bits = fxas21002c_hpf_value_from_sel(data, sel);
+	if (sel_bits < 0)
+		return sel_bits;
+
+	return fxas21002c_write(data, F_SEL, sel_bits);
+}
+
+static int fxas21002c_scale_get(struct fxas21002c_data *data, int *val)
+{
+	int fs_bits;
+	int scale;
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_field_read(data->regmap_fields[F_FS], &fs_bits);
+	if (ret < 0)
+		goto data_unlock;
+
+	scale = fxas21002c_range_fs_from_value(data, fs_bits);
+	if (scale < 0) {
+		ret = scale;
+		goto data_unlock;
+	}
+
+	*val = scale;
+
+data_unlock:
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static int fxas21002c_scale_set(struct fxas21002c_data *data, int range)
+{
+	int fs_bits;
+
+	fs_bits = fxas21002c_range_value_from_fs(data, range);
+	if (fs_bits < 0)
+		return fs_bits;
+
+	return fxas21002c_write(data, F_FS, fs_bits);
+}
+
+static int fxas21002c_read_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan, int *val,
+			       int *val2, long mask)
+{
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return fxas21002c_temp_get(data, val);
+		case IIO_ANGL_VEL:
+			return fxas21002c_axis_get(data, chan->scan_index, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*val2 = FXAS21002C_SCALE_FRACTIONAL;
+			ret = fxas21002c_scale_get(data, val);
+			if (ret < 0)
+				return ret;
+
+			return IIO_VAL_FRACTIONAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		*val = 0;
+		return fxas21002c_lpf_get(data, val2);
+	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+		*val = 0;
+		return fxas21002c_hpf_get(data, val2);
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val2 = 0;
+		return fxas21002c_odr_get(data, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int fxas21002c_write_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan, int val,
+				int val2, long mask)
+{
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int range;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val2)
+			return -EINVAL;
+
+		return fxas21002c_odr_set(data, val);
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		if (val)
+			return -EINVAL;
+
+		val2 = val2 / 10000;
+		return fxas21002c_lpf_set(data, val2);
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			range = (((val * 1000 + val2 / 1000) *
+				  FXAS21002C_SCALE_FRACTIONAL) / 1000);
+			return fxas21002c_scale_set(data, range);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
+		return fxas21002c_hpf_set(data, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800");
+
+static IIO_CONST_ATTR(in_anglvel_filter_low_pass_3db_frequency_available,
+		      "0.32 0.16 0.08");
+
+static IIO_CONST_ATTR(in_anglvel_filter_high_pass_3db_frequency_available,
+		      "0.018750 0.009625 0.004875 0.002475");
+
+static IIO_CONST_ATTR(in_anglvel_scale_available,
+		      "125.0 62.5 31.25 15.625 7.8125");
+
+static struct attribute *fxas21002c_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_filter_low_pass_3db_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_filter_high_pass_3db_frequency_available.dev_attr.attr,
+	&iio_const_attr_in_anglvel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group fxas21002c_attrs_group = {
+	.attrs = fxas21002c_attributes,
+};
+
+#define FXAS21002C_CHANNEL(_axis) {					\
+	.type = IIO_ANGL_VEL,						\
+	.modified = 1,							\
+	.channel2 = IIO_MOD_##_axis,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
+		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |	\
+		BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY) |	\
+		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
+	.scan_index = CHANNEL_SCAN_INDEX_##_axis,			\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 16,						\
+		.storagebits = 16,					\
+		.endianness = IIO_BE,					\
+	},								\
+}
+
+static const struct iio_chan_spec fxas21002c_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = -1,
+	},
+	FXAS21002C_CHANNEL(X),
+	FXAS21002C_CHANNEL(Y),
+	FXAS21002C_CHANNEL(Z),
+};
+
+static const struct iio_info fxas21002c_info = {
+	.attrs			= &fxas21002c_attrs_group,
+	.read_raw		= &fxas21002c_read_raw,
+	.write_raw		= &fxas21002c_write_raw,
+};
+
+static irqreturn_t fxas21002c_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = regmap_bulk_read(data->regmap, FXAS21002C_REG_OUT_X_MSB,
+			       data->buffer, CHANNEL_SCAN_MAX * sizeof(s16));
+	if (ret < 0)
+		goto out_unlock;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   data->timestamp);
+
+out_unlock:
+	mutex_unlock(&data->lock);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int fxas21002c_chip_init(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int chip_id;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_WHO_AM_I], &chip_id);
+	if (ret < 0)
+		return ret;
+
+	if (chip_id != FXAS21002C_CHIP_ID_1 &&
+	    chip_id != FXAS21002C_CHIP_ID_2) {
+		dev_err(dev, "chip id 0x%02x is not supported\n", chip_id);
+		return -EINVAL;
+	}
+
+	data->chip_id = chip_id;
+
+	ret = fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	/* Set ODR to 200HZ as default */
+	ret = fxas21002c_odr_set(data, 200);
+	if (ret < 0)
+		dev_err(dev, "failed to set ODR: %d\n", ret);
+
+	return ret;
+}
+
+static int fxas21002c_data_rdy_trigger_set_state(struct iio_trigger *trig,
+						 bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+
+	return regmap_field_write(data->regmap_fields[F_INT_EN_DRDY], state);
+}
+
+static const struct iio_trigger_ops fxas21002c_trigger_ops = {
+	.set_trigger_state = &fxas21002c_data_rdy_trigger_set_state,
+};
+
+static irqreturn_t fxas21002c_data_rdy_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+
+	data->timestamp = iio_get_time_ns(indio_dev);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t fxas21002c_data_rdy_thread(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct fxas21002c_data *data = iio_priv(indio_dev);
+	unsigned int data_ready;
+	int ret;
+
+	ret = regmap_field_read(data->regmap_fields[F_SRC_DRDY], &data_ready);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	if (!data_ready)
+		return IRQ_NONE;
+
+	iio_trigger_poll_chained(data->dready_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int fxas21002c_trigger_probe(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct device_node *np = indio_dev->dev.of_node;
+	unsigned long irq_trig;
+	bool irq_open_drain;
+	int irq1;
+	int ret;
+
+	if (!data->irq)
+		return 0;
+
+	irq1 = of_irq_get_byname(np, "INT1");
+
+	if (irq1 == data->irq) {
+		dev_info(dev, "using interrupt line INT1\n");
+		ret = regmap_field_write(data->regmap_fields[F_INT_CFG_DRDY],
+					 1);
+		if (ret < 0)
+			return ret;
+	}
+
+	dev_info(dev, "using interrupt line INT2\n");
+
+	irq_open_drain = of_property_read_bool(np, "drive-open-drain");
+
+	data->dready_trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+						   indio_dev->name,
+						   indio_dev->id);
+	if (!data->dready_trig)
+		return -ENOMEM;
+
+	irq_trig = irqd_get_trigger_type(irq_get_irq_data(data->irq));
+
+	if (irq_trig == IRQF_TRIGGER_RISING) {
+		ret = regmap_field_write(data->regmap_fields[F_IPOL], 1);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (irq_open_drain)
+		irq_trig |= IRQF_SHARED;
+
+	ret = devm_request_threaded_irq(dev, data->irq,
+					fxas21002c_data_rdy_handler,
+					fxas21002c_data_rdy_thread,
+					irq_trig, "fxas21002c_data_ready",
+					indio_dev);
+	if (ret < 0)
+		return ret;
+
+	data->dready_trig->dev.parent = dev;
+	data->dready_trig->ops = &fxas21002c_trigger_ops;
+	iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+
+	return devm_iio_trigger_register(dev, data->dready_trig);
+}
+
+static int fxas21002c_power_enable(struct fxas21002c_data *data)
+{
+	int ret;
+
+	ret = regulator_enable(data->vdd);
+	if (ret < 0)
+		return ret;
+
+	ret = regulator_enable(data->vddio);
+	if (ret < 0) {
+		regulator_disable(data->vdd);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void fxas21002c_power_disable(struct fxas21002c_data *data)
+{
+	regulator_disable(data->vdd);
+	regulator_disable(data->vddio);
+}
+
+static void fxas21002c_power_disable_action(void *_data)
+{
+	struct fxas21002c_data *data = _data;
+
+	fxas21002c_power_disable(data);
+}
+
+static int fxas21002c_regulators_get(struct fxas21002c_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+
+	data->vdd = devm_regulator_get(dev->parent, "vdd");
+	if (IS_ERR(data->vdd))
+		return PTR_ERR(data->vdd);
+
+	data->vddio = devm_regulator_get(dev->parent, "vddio");
+
+	return PTR_ERR_OR_ZERO(data->vddio);
+}
+
+int fxas21002c_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			  const char *name)
+{
+	struct fxas21002c_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap_field *f;
+	int i;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+	data->irq = irq;
+	data->regmap = regmap;
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		f = devm_regmap_field_alloc(dev, data->regmap,
+					    fxas21002c_reg_fields[i]);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+
+		data->regmap_fields[i] = f;
+	}
+
+	mutex_init(&data->lock);
+
+	ret = fxas21002c_regulators_get(data);
+	if (ret < 0)
+		return ret;
+
+	ret = fxas21002c_power_enable(data);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, fxas21002c_power_disable_action,
+				       data);
+	if (ret < 0)
+		return ret;
+
+	ret = fxas21002c_chip_init(data);
+	if (ret < 0)
+		return ret;
+
+	indio_dev->dev.parent = dev;
+	indio_dev->channels = fxas21002c_channels;
+	indio_dev->num_channels = ARRAY_SIZE(fxas21002c_channels);
+	indio_dev->name = name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &fxas21002c_info;
+
+	ret = fxas21002c_trigger_probe(data);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      fxas21002c_trigger_handler, NULL);
+	if (ret < 0)
+		return ret;
+
+	ret = pm_runtime_set_active(dev);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, 2000);
+	pm_runtime_use_autosuspend(dev);
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto pm_disable;
+
+	return 0;
+
+pm_disable:
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fxas21002c_core_probe);
+
+void fxas21002c_core_remove(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+
+	iio_device_unregister(indio_dev);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+}
+EXPORT_SYMBOL_GPL(fxas21002c_core_remove);
+
+static int __maybe_unused fxas21002c_suspend(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	fxas21002c_mode_set(data, FXAS21002C_MODE_STANDBY);
+	fxas21002c_power_disable(data);
+
+	return 0;
+}
+
+static int __maybe_unused fxas21002c_resume(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+	int ret;
+
+	ret = fxas21002c_power_enable(data);
+	if (ret < 0)
+		return ret;
+
+	return fxas21002c_mode_set(data, data->prev_mode);
+}
+
+static int __maybe_unused fxas21002c_runtime_suspend(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return fxas21002c_mode_set(data, FXAS21002C_MODE_READY);
+}
+
+static int __maybe_unused fxas21002c_runtime_resume(struct device *dev)
+{
+	struct fxas21002c_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return fxas21002c_mode_set(data, FXAS21002C_MODE_ACTIVE);
+}
+
+const struct dev_pm_ops fxas21002c_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(fxas21002c_suspend, fxas21002c_resume)
+	SET_RUNTIME_PM_OPS(fxas21002c_runtime_suspend,
+			   fxas21002c_runtime_resume, NULL)
+};
+EXPORT_SYMBOL_GPL(fxas21002c_pm_ops);
+
+MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("FXAS21002C Gyro driver");