iio: accel: kxcjk1013 3-axis accelerometer driver

This patch adds IIO driver for KXCJK 1013 triaxis accelerometer sensor.
The specifications for this driver is downloaded from:
http://www.kionix.com/sites/default/files/KXCJK-1013%20Specifications%20Rev%202.pdf

Signed-off-by: Srinivas Pandruvada <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/accel/Kconfig

···
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma8452.
 
+config KXCJK1013
+	tristate "Kionix 3-Axis Accelerometer Driver"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here if you want to build a driver for the Kionix KXCJK-1013
+	  triaxial acceleration sensor.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called kxcjk-1013.
+
 endmenu

drivers/iio/accel/Makefile

···
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_BMA180) += bma180.o
 obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
+obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
 obj-$(CONFIG_KXSD9)	+= kxsd9.o
 obj-$(CONFIG_MMA8452)	+= mma8452.o
 

drivers/iio/accel/kxcjk-1013.c

···
+/*
+ * KXCJK-1013 3-axis accelerometer driver
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/accel/kxcjk_1013.h>
+
+#define KXCJK1013_DRV_NAME "kxcjk1013"
+#define KXCJK1013_IRQ_NAME "kxcjk1013_event"
+
+#define KXCJK1013_REG_XOUT_L		0x06
+/*
+ * From low byte X axis register, all the other addresses of Y and Z can be
+ * obtained by just applying axis offset. The following axis defines are just
+ * provide clarity, but not used.
+ */
+#define KXCJK1013_REG_XOUT_H		0x07
+#define KXCJK1013_REG_YOUT_L		0x08
+#define KXCJK1013_REG_YOUT_H		0x09
+#define KXCJK1013_REG_ZOUT_L		0x0A
+#define KXCJK1013_REG_ZOUT_H		0x0B
+
+#define KXCJK1013_REG_DCST_RESP		0x0C
+#define KXCJK1013_REG_WHO_AM_I		0x0F
+#define KXCJK1013_REG_INT_SRC1		0x16
+#define KXCJK1013_REG_INT_SRC2		0x17
+#define KXCJK1013_REG_STATUS_REG	0x18
+#define KXCJK1013_REG_INT_REL		0x1A
+#define KXCJK1013_REG_CTRL1		0x1B
+#define KXCJK1013_REG_CTRL2		0x1D
+#define KXCJK1013_REG_INT_CTRL1		0x1E
+#define KXCJK1013_REG_INT_CTRL2		0x1F
+#define KXCJK1013_REG_DATA_CTRL		0x21
+#define KXCJK1013_REG_WAKE_TIMER	0x29
+#define KXCJK1013_REG_SELF_TEST		0x3A
+#define KXCJK1013_REG_WAKE_THRES	0x6A
+
+#define KXCJK1013_REG_CTRL1_BIT_PC1	BIT(7)
+#define KXCJK1013_REG_CTRL1_BIT_RES	BIT(6)
+#define KXCJK1013_REG_CTRL1_BIT_DRDY	BIT(5)
+#define KXCJK1013_REG_CTRL1_BIT_GSEL1	BIT(4)
+#define KXCJK1013_REG_CTRL1_BIT_GSEL0	BIT(3)
+#define KXCJK1013_REG_CTRL1_BIT_WUFE	BIT(1)
+#define KXCJK1013_REG_INT_REG1_BIT_IEA	BIT(4)
+#define KXCJK1013_REG_INT_REG1_BIT_IEN	BIT(5)
+
+#define KXCJK1013_DATA_MASK_12_BIT	0x0FFF
+#define KXCJK1013_MAX_STARTUP_TIME_US	100000
+
+struct kxcjk1013_data {
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	bool trig_mode;
+	struct mutex mutex;
+	s16 buffer[8];
+	int power_state;
+	u8 odr_bits;
+	bool active_high_intr;
+};
+
+enum kxcjk1013_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+enum kxcjk1013_mode {
+	STANDBY,
+	OPERATION,
+};
+
+static const struct {
+	int val;
+	int val2;
+	int odr_bits;
+} samp_freq_table[] = { {0, 781000, 0x08}, {1, 563000, 0x09},
+			{3, 125000, 0x0A}, {6, 25000, 0x0B}, {12, 5000, 0},
+			{25, 0, 0x01}, {50, 0, 0x02}, {100, 0, 0x03},
+			{200, 0, 0x04}, {400, 0, 0x05}, {800, 0, 0x06},
+			{1600, 0, 0x07} };
+
+/* Refer to section 4 of the specification */
+static const struct {
+	int odr_bits;
+	int usec;
+} odr_start_up_times[] = { {0x08, 100000}, {0x09, 100000}, {0x0A, 100000},
+			   {0x0B, 100000}, { 0, 80000}, {0x01, 41000},
+			   {0x02, 21000}, {0x03, 11000}, {0x04, 6400},
+			   {0x05, 3900}, {0x06, 2700}, {0x07, 2100} };
+
+static int kxcjk1013_set_mode(struct kxcjk1013_data *data,
+			      enum kxcjk1013_mode mode)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_CTRL1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+		return ret;
+	}
+
+	if (mode == STANDBY)
+		ret &= ~KXCJK1013_REG_CTRL1_BIT_PC1;
+	else
+		ret |= KXCJK1013_REG_CTRL1_BIT_PC1;
+
+	ret = i2c_smbus_write_byte_data(data->client,
+					KXCJK1013_REG_CTRL1, ret);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int kxcjk1013_chip_ack_intr(struct kxcjk1013_data *data)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_INT_REL);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing reg_int_rel\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int kxcjk1013_chip_init(struct kxcjk1013_data *data)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_WHO_AM_I);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading who_am_i\n");
+		return ret;
+	}
+
+	dev_dbg(&data->client->dev, "KXCJK1013 Chip Id %x\n", ret);
+
+	ret = kxcjk1013_set_mode(data, STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_CTRL1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+		return ret;
+	}
+
+	/* Setting range to 4G */
+	ret |= KXCJK1013_REG_CTRL1_BIT_GSEL0;
+	ret &= ~KXCJK1013_REG_CTRL1_BIT_GSEL1;
+
+	/* Set 12 bit mode */
+	ret |= KXCJK1013_REG_CTRL1_BIT_RES;
+
+	ret = i2c_smbus_write_byte_data(data->client, KXCJK1013_REG_CTRL1,
+					ret);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_ctrl\n");
+		return ret;
+	}
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_DATA_CTRL);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_data_ctrl\n");
+		return ret;
+	}
+
+	data->odr_bits = ret;
+
+	/* Set up INT polarity */
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_INT_CTRL1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_int_ctrl1\n");
+		return ret;
+	}
+
+	if (data->active_high_intr)
+		ret |= KXCJK1013_REG_INT_REG1_BIT_IEA;
+	else
+		ret &= ~KXCJK1013_REG_INT_REG1_BIT_IEA;
+
+	ret = i2c_smbus_write_byte_data(data->client, KXCJK1013_REG_INT_CTRL1,
+					ret);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing reg_int_ctrl1\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int kxcjk1013_chip_setup_interrupt(struct kxcjk1013_data *data,
+					  bool status)
+{
+	int ret;
+
+	/* This is requirement by spec to change state to STANDBY */
+	ret = kxcjk1013_set_mode(data, STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_INT_CTRL1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_int_ctrl1\n");
+		return ret;
+	}
+
+	if (status)
+		ret |= KXCJK1013_REG_INT_REG1_BIT_IEN;
+	else
+		ret &= ~KXCJK1013_REG_INT_REG1_BIT_IEN;
+
+	ret = i2c_smbus_write_byte_data(data->client, KXCJK1013_REG_INT_CTRL1,
+					ret);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing reg_int_ctrl1\n");
+		return ret;
+	}
+
+	ret = i2c_smbus_read_byte_data(data->client, KXCJK1013_REG_CTRL1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+		return ret;
+	}
+
+	if (status)
+		ret |= KXCJK1013_REG_CTRL1_BIT_DRDY;
+	else
+		ret &= ~KXCJK1013_REG_CTRL1_BIT_DRDY;
+
+	ret = i2c_smbus_write_byte_data(data->client,
+					KXCJK1013_REG_CTRL1, ret);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int kxcjk1013_convert_freq_to_bit(int val, int val2)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(samp_freq_table); ++i) {
+		if (samp_freq_table[i].val == val &&
+			samp_freq_table[i].val2 == val2) {
+			return samp_freq_table[i].odr_bits;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int kxcjk1013_set_odr(struct kxcjk1013_data *data, int val, int val2)
+{
+	int ret;
+	int odr_bits;
+
+	odr_bits = kxcjk1013_convert_freq_to_bit(val, val2);
+	if (odr_bits < 0)
+		return odr_bits;
+
+	/* To change ODR, the chip must be set to STANDBY as per spec */
+	ret = kxcjk1013_set_mode(data, STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, KXCJK1013_REG_DATA_CTRL,
+					odr_bits);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error writing data_ctrl\n");
+		return ret;
+	}
+
+	data->odr_bits = odr_bits;
+
+	/* Check, if the ODR is changed after data enable */
+	if (data->power_state) {
+		/* Set the state back to operation */
+		ret = kxcjk1013_set_mode(data, OPERATION);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int kxcjk1013_get_odr(struct kxcjk1013_data *data, int *val, int *val2)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(samp_freq_table); ++i) {
+		if (samp_freq_table[i].odr_bits == data->odr_bits) {
+			*val = samp_freq_table[i].val;
+			*val2 = samp_freq_table[i].val2;
+			return IIO_VAL_INT_PLUS_MICRO;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int kxcjk1013_get_acc_reg(struct kxcjk1013_data *data, int axis)
+{
+	u8 reg = KXCJK1013_REG_XOUT_L + axis * 2;
+	int ret;
+
+	ret = i2c_smbus_read_word_data(data->client, reg);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"failed to read accel_%c registers\n", 'x' + axis);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int kxcjk1013_get_startup_times(struct kxcjk1013_data *data)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(odr_start_up_times); ++i) {
+		if (odr_start_up_times[i].odr_bits == data->odr_bits)
+			return odr_start_up_times[i].usec;
+	}
+
+	return KXCJK1013_MAX_STARTUP_TIME_US;
+}
+
+static int kxcjk1013_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan, int *val,
+			      int *val2, long mask)
+{
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->mutex);
+		if (iio_buffer_enabled(indio_dev))
+			ret = -EBUSY;
+		else {
+			int sleep_val;
+
+			ret = kxcjk1013_set_mode(data, OPERATION);
+			if (ret < 0)
+				return ret;
+			++data->power_state;
+			sleep_val = kxcjk1013_get_startup_times(data);
+			if (sleep_val < 20000)
+				usleep_range(sleep_val, 20000);
+			else
+				msleep_interruptible(sleep_val/1000);
+			ret = kxcjk1013_get_acc_reg(data, chan->scan_index);
+			if (--data->power_state == 0)
+				kxcjk1013_set_mode(data, STANDBY);
+		}
+		mutex_unlock(&data->mutex);
+
+		if (ret < 0)
+			return ret;
+
+		*val = sign_extend32(ret >> 4, 11);
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = 19163; /* range +-4g (4/2047*9.806650) */
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&data->mutex);
+		ret = kxcjk1013_get_odr(data, val, val2);
+		mutex_unlock(&data->mutex);
+		return ret;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int kxcjk1013_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan, int val,
+			       int val2, long mask)
+{
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&data->mutex);
+		ret = kxcjk1013_set_odr(data, val, val2);
+		mutex_unlock(&data->mutex);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int kxcjk1013_validate_trigger(struct iio_dev *indio_dev,
+				      struct iio_trigger *trig)
+{
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+
+	if (data->trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
+	"0.781000 1.563000 3.125000 6.250000 12.500000 25 50 100 200 400 800 1600");
+
+static struct attribute *kxcjk1013_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group kxcjk1013_attrs_group = {
+	.attrs = kxcjk1013_attributes,
+};
+
+#define KXCJK1013_CHANNEL(_axis) {					\
+	.type = IIO_ACCEL,						\
+	.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_SAMP_FREQ),		\
+	.scan_index = AXIS_##_axis,					\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 12,						\
+		.storagebits = 16,					\
+		.shift = 4,						\
+		.endianness = IIO_LE,					\
+	},								\
+}
+
+static const struct iio_chan_spec kxcjk1013_channels[] = {
+	KXCJK1013_CHANNEL(X),
+	KXCJK1013_CHANNEL(Y),
+	KXCJK1013_CHANNEL(Z),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct iio_info kxcjk1013_info = {
+	.attrs			= &kxcjk1013_attrs_group,
+	.read_raw		= kxcjk1013_read_raw,
+	.write_raw		= kxcjk1013_write_raw,
+	.validate_trigger	= kxcjk1013_validate_trigger,
+	.driver_module		= THIS_MODULE,
+};
+
+static irqreturn_t kxcjk1013_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+	int bit, ret, i = 0;
+
+	mutex_lock(&data->mutex);
+
+	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
+			 indio_dev->masklength) {
+		ret = kxcjk1013_get_acc_reg(data, bit);
+		if (ret < 0) {
+			kxcjk1013_chip_ack_intr(data);
+			mutex_unlock(&data->mutex);
+			goto err;
+		}
+		data->buffer[i++] = ret;
+	}
+
+	kxcjk1013_chip_ack_intr(data);
+
+	mutex_unlock(&data->mutex);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int kxcjk1013_data_rdy_trigger_set_state(struct iio_trigger *trig,
+						bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+	if (state) {
+		kxcjk1013_chip_setup_interrupt(data, true);
+		kxcjk1013_set_mode(data, OPERATION);
+		++data->power_state;
+	} else {
+		if (--data->power_state)
+			return 0;
+		kxcjk1013_chip_setup_interrupt(data, false);
+		kxcjk1013_set_mode(data, STANDBY);
+	}
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops kxcjk1013_trigger_ops = {
+	.set_trigger_state = kxcjk1013_data_rdy_trigger_set_state,
+	.owner = THIS_MODULE,
+};
+
+static int kxcjk1013_acpi_gpio_probe(struct i2c_client *client,
+				     struct kxcjk1013_data *data)
+{
+	const struct acpi_device_id *id;
+	struct device *dev;
+	struct gpio_desc *gpio;
+	int ret;
+
+	if (!client)
+		return -EINVAL;
+
+	dev = &client->dev;
+	if (!ACPI_HANDLE(dev))
+		return -ENODEV;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -ENODEV;
+
+	/* data ready gpio interrupt pin */
+	gpio = devm_gpiod_get_index(dev, "kxcjk1013_int", 0);
+	if (IS_ERR(gpio)) {
+		dev_err(dev, "acpi gpio get index failed\n");
+		return PTR_ERR(gpio);
+	}
+
+	ret = gpiod_direction_input(gpio);
+	if (ret)
+		return ret;
+
+	ret = gpiod_to_irq(gpio);
+
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
+
+	return ret;
+}
+
+static int kxcjk1013_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	struct kxcjk1013_data *data;
+	struct iio_dev *indio_dev;
+	struct iio_trigger *trig = NULL;
+	struct kxcjk_1013_platform_data *pdata;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	pdata = dev_get_platdata(&client->dev);
+	if (pdata)
+		data->active_high_intr = pdata->active_high_intr;
+	else
+		data->active_high_intr = true; /* default polarity */
+
+	ret = kxcjk1013_chip_init(data);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&data->mutex);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->channels = kxcjk1013_channels;
+	indio_dev->num_channels = ARRAY_SIZE(kxcjk1013_channels);
+	indio_dev->name = KXCJK1013_DRV_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &kxcjk1013_info;
+
+	if (client->irq < 0)
+		client->irq = kxcjk1013_acpi_gpio_probe(client, data);
+
+	if (client->irq >= 0) {
+		trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
+					 indio_dev->id);
+		if (!trig)
+			return -ENOMEM;
+
+		data->trig_mode = true;
+
+		ret = devm_request_irq(&client->dev, client->irq,
+					iio_trigger_generic_data_rdy_poll,
+					IRQF_TRIGGER_RISING,
+					KXCJK1013_IRQ_NAME,
+					trig);
+		if (ret) {
+			dev_err(&client->dev, "unable to request IRQ\n");
+			goto err_trigger_free;
+		}
+
+		trig->dev.parent = &client->dev;
+		trig->ops = &kxcjk1013_trigger_ops;
+		iio_trigger_set_drvdata(trig, indio_dev);
+		data->trig = trig;
+		indio_dev->trig = trig;
+
+		ret = iio_trigger_register(trig);
+		if (ret)
+			goto err_trigger_free;
+
+		ret = iio_triggered_buffer_setup(indio_dev,
+						&iio_pollfunc_store_time,
+						kxcjk1013_trigger_handler,
+						NULL);
+		if (ret < 0) {
+			dev_err(&client->dev,
+					"iio triggered buffer setup failed\n");
+			goto err_trigger_unregister;
+		}
+	}
+
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		goto err_buffer_cleanup;
+	}
+
+	return 0;
+
+err_buffer_cleanup:
+	if (data->trig_mode)
+		iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	if (data->trig_mode)
+		iio_trigger_unregister(trig);
+err_trigger_free:
+	if (data->trig_mode)
+		iio_trigger_free(trig);
+
+	return ret;
+}
+
+static int kxcjk1013_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+
+	if (data->trig_mode) {
+		iio_triggered_buffer_cleanup(indio_dev);
+		iio_trigger_unregister(data->trig);
+		iio_trigger_free(data->trig);
+	}
+
+	mutex_lock(&data->mutex);
+	kxcjk1013_set_mode(data, STANDBY);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int kxcjk1013_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+	kxcjk1013_set_mode(data, STANDBY);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static int kxcjk1013_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct kxcjk1013_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+
+	if (data->power_state)
+		kxcjk1013_set_mode(data, OPERATION);
+
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(kxcjk1013_pm_ops, kxcjk1013_suspend, kxcjk1013_resume);
+#define KXCJK1013_PM_OPS (&kxcjk1013_pm_ops)
+#else
+#define KXCJK1013_PM_OPS NULL
+#endif
+
+static const struct acpi_device_id kx_acpi_match[] = {
+	{"KXCJ1013", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, kx_acpi_match);
+
+static const struct i2c_device_id kxcjk1013_id[] = {
+	{"kxcjk1013", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, kxcjk1013_id);
+
+static struct i2c_driver kxcjk1013_driver = {
+	.driver = {
+		.name	= KXCJK1013_DRV_NAME,
+		.acpi_match_table = ACPI_PTR(kx_acpi_match),
+		.pm	= KXCJK1013_PM_OPS,
+	},
+	.probe		= kxcjk1013_probe,
+	.remove		= kxcjk1013_remove,
+	.id_table	= kxcjk1013_id,
+};
+module_i2c_driver(kxcjk1013_driver);
+
+MODULE_AUTHOR("Srinivas Pandruvada <[e-mail]>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("KXCJK1013 accelerometer driver");

include/linux/iio/accel/kxcjk_1013.h

···
+/*
+ * KXCJK-1013 3-axis accelerometer Interface
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef __IIO_KXCJK_1013_H__
+#define __IIO_KXCJK_1013_H__
+
+struct kxcjk_1013_platform_data {
+	bool active_high_intr;
+};
+
+#endif