[PATCH] iio: accel: kxcjk1013 3-axis accelerometer driver

[PATCH] iio: accel: kxcjk1013 3-axis accelerometer driver

[Srinivas Pandruvada]

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 <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/accel/Kconfig      |  12 +
 drivers/iio/accel/Makefile     |   2 +
 drivers/iio/accel/kxcjk-1013.c | 720 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 734 insertions(+)
 create mode 100644 drivers/iio/accel/kxcjk-1013.c

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 1e120fa..12addf2 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -77,4 +77,16 @@ config MMA8452
 	  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
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index dc0e379..4d153be 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -14,3 +14,5 @@ st_accel-$(CONFIG_IIO_BUFFER) += st_accel_buffer.o
 
 obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
 obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
+
+obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
new file mode 100644
index 0000000..299d441
--- /dev/null
+++ b/drivers/iio/accel/kxcjk-1013.c
@@ -0,0 +1,720 @@
+/*
+ * 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/of.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>
+
+#define KXCJK1013_DRV_NAME "kxcjk1013"
+#define KXCJK1013_IRQ_NAME "kxcjk1013_event"
+
+#define KXCJK1013_REG_XOUT_L		0x06
+#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	100000
+
+struct kxcjk1013_data {
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	bool	trig_mode;
+	struct mutex mutex;
+	s16 buffer[3];
+	atomic_t power_state;
+	int gpio_irq;
+	u8 odr_bits;
+};
+
+enum kxcjk1013_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+enum kxcjk1013_mode {
+	STANDBY,
+	OPERATION,
+};
+
+struct {
+	int val;
+	int val2;
+	int odr_bits;
+} samp_freq_table[] = { {0, 781, 0x08}, {1, 563, 0x09}, {3, 125, 0x0A},
+			{6, 25, 0x0B}, {12, 5, 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 */
+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_setup_polarity(struct kxcjk1013_data *data,
+					  bool active_high)
+{
+	int 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 (active_high)
+		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 ret;
+}
+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 = 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;
+	}
+
+	ret = kxcjk1013_set_mode(data, STANDBY);
+
+	/* 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;
+
+	/* Active high interrupt */
+	ret = kxcjk1013_chip_setup_polarity(data, true);
+
+	return ret;
+}
+
+static int kxcjk1013_chip_setup_interrupt(struct kxcjk1013_data *data,
+					  bool status)
+{
+	int ret;
+
+	kxcjk1013_set_mode(data, STANDBY);
+
+	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; 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 / 1000);
+	if (odr_bits < 0)
+		return odr_bits;
+
+	kxcjk1013_set_mode(data, STANDBY);
+
+	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;
+
+	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 * 1000;
+			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;
+}
+
+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;
+
+			kxcjk1013_set_mode(data, OPERATION);
+			atomic_inc(&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 (atomic_dec_and_test(&data->power_state))
+				kxcjk1013_set_mode(data, STANDBY);
+		}
+		mutex_unlock(&data->mutex);
+
+		if (ret < 0)
+			return ret;
+
+		*val = (s16)ret >> chan->scan_type.shift;
+		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 IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
+		"0.781 1.563 3.125 6.25 12.5 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,						\
+	},								\
+}
+
+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,
+	.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);
+	int64_t time_ns = iio_get_time_ns();
+	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, time_ns);
+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);
+
+	if (state) {
+		kxcjk1013_chip_setup_interrupt(data, true);
+		kxcjk1013_set_mode(data, OPERATION);
+		atomic_inc(&data->power_state);
+	} else {
+		if (!atomic_dec_and_test(&data->power_state))
+			return 0;
+		kxcjk1013_chip_setup_interrupt(data, false);
+		kxcjk1013_set_mode(data, STANDBY);
+	}
+
+	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);
+
+	if (ret < 0)
+		return ret;
+
+	data->gpio_irq = ret;
+
+	/* Update client irq if its invalid */
+	if (client->irq < 0)
+		client->irq = data->gpio_irq;
+
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio),
+							data->gpio_irq);
+
+	return 0;
+}
+
+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;
+	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;
+
+	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;
+
+	kxcjk1013_acpi_gpio_probe(client, data);
+
+	if (client->irq < 0) {
+		kxcjk1013_chip_setup_interrupt(data, false);
+		goto skip_setup_trigger;
+	}
+
+	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, NULL,
+			kxcjk1013_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		goto err_trigger_unregister;
+	}
+
+skip_setup_trigger:
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		if (data->trig_mode)
+			goto err_buffer_cleanup;
+		else
+			return ret;
+	}
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	iio_trigger_unregister(trig);
+err_trigger_free:
+	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 SIMPLE_DEV_PM_OPS(kxcjk1013_pm_ops, kxcjk1013_suspend, NULL);
+#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 <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("KXCJK1013 accelerometer driver");
-- 
1.7.11.7

Re: [PATCH] iio: accel: kxcjk1013 3-axis accelerometer driver

[Peter Meerwald]

> 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

looks like a Freescale part (from the register layout)

comments inline

> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 1e120fa..12addf2 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -77,4 +77,16 @@ config MMA8452
>  	  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
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index dc0e379..4d153be 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -14,3 +14,5 @@ st_accel-$(CONFIG_IIO_BUFFER) += st_accel_buffer.o
>  
>  obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
>  obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
> +
> +obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
> diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
> new file mode 100644
> index 0000000..299d441
> --- /dev/null
> +++ b/drivers/iio/accel/kxcjk-1013.c
> @@ -0,0 +1,720 @@
> +/*
> + * 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/of.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>
> +
> +#define KXCJK1013_DRV_NAME "kxcjk1013"
> +#define KXCJK1013_IRQ_NAME "kxcjk1013_event"
> +
> +#define KXCJK1013_REG_XOUT_L		0x06
> +#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

all these (_L, _H) are not really used

> +#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	100000

time unit?

> +
> +struct kxcjk1013_data {
> +	struct i2c_client *client;
> +	struct iio_trigger *trig;
> +	bool	trig_mode;
> +	struct mutex mutex;
> +	s16 buffer[3];
> +	atomic_t power_state;
> +	int gpio_irq;
> +	u8 odr_bits;
> +};
> +
> +enum kxcjk1013_axis {
> +	AXIS_X,
> +	AXIS_Y,
> +	AXIS_Z,
> +};
> +
> +enum kxcjk1013_mode {
> +	STANDBY,
> +	OPERATION,
> +};
> +
> +struct {
> +	int val;
> +	int val2;
> +	int odr_bits;
> +} samp_freq_table[] = { {0, 781, 0x08}, {1, 563, 0x09}, {3, 125, 0x0A},
> +			{6, 25, 0x0B}, {12, 5, 0}, {25, 0, 0x01},
> +			{50, 0, 0x02}, {100, 0, 0x03}, {200, 0, 0x04},
> +			{400, 0, 0x05}, {800, 0, 0x06}, {1600, 0, 0x07} };

static const

> +
> +/* Refer to section 4 of the specification */
> +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 const

> +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_setup_polarity(struct kxcjk1013_data *data,
> +					  bool active_high)
> +{
> +	int 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 (active_high)
> +		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 ret;
> +}

newline

> +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 = 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;
> +	}

reg_ctrl1 not used

> +
> +	ret = kxcjk1013_set_mode(data, STANDBY);

return value not checked

> +
> +	/* 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;
> +	}
> +
extra newline
> +
> +	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;
> +
> +	/* Active high interrupt */
> +	ret = kxcjk1013_chip_setup_polarity(data, true);

return kxcjk1013_chip_setup_polarity(...)
> +
> +	return ret;
> +}
> +
> +static int kxcjk1013_chip_setup_interrupt(struct kxcjk1013_data *data,
> +					  bool status)
> +{
> +	int ret;
> +
> +	kxcjk1013_set_mode(data, STANDBY);
> +
> +	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; 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 / 1000);
> +	if (odr_bits < 0)
> +		return odr_bits;
> +
> +	kxcjk1013_set_mode(data, STANDBY);
> +
> +	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;
> +
> +	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 * 1000;
> +			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;
> +}
> +
> +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;
> +
> +			kxcjk1013_set_mode(data, OPERATION);
return value?
> +			atomic_inc(&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);

val / 1000

> +			ret = kxcjk1013_get_acc_reg(data, chan->scan_index);
> +			if (atomic_dec_and_test(&data->power_state))
> +				kxcjk1013_set_mode(data, STANDBY);
> +		}
> +		mutex_unlock(&data->mutex);
> +
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = (s16)ret >> chan->scan_type.shift;

maybe sign_extend32?

> +		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 IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
> +		"0.781 1.563 3.125 6.25 12.5 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 seems to be 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,
> +	.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);
> +	int64_t time_ns = iio_get_time_ns();
> +	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, time_ns);
> +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);
> +
> +	if (state) {
> +		kxcjk1013_chip_setup_interrupt(data, true);
> +		kxcjk1013_set_mode(data, OPERATION);
> +		atomic_inc(&data->power_state);
> +	} else {
> +		if (!atomic_dec_and_test(&data->power_state))
> +			return 0;
> +		kxcjk1013_chip_setup_interrupt(data, false);
> +		kxcjk1013_set_mode(data, STANDBY);
> +	}
> +
> +	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;
remove newline
> +
> +	if (!ACPI_HANDLE(dev))
> +		return -ENODEV;
> +
> +	id = acpi_match_device(dev->driver->acpi_match_table, dev);
remove newline
> +
> +	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);

remove newline
> +
> +	if (ret)
> +		return ret;
> +
> +	ret = gpiod_to_irq(gpio);
> +
remove newline
> +	if (ret < 0)
> +		return ret;
> +
> +	data->gpio_irq = ret;
> +
> +	/* Update client irq if its invalid */

it's 

> +	if (client->irq < 0)
> +		client->irq = data->gpio_irq;

client->irq > 0 is valid, so should be 
if (client->irq <= 0) ...

(not sure)

> +
> +	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio),
> +							data->gpio_irq);
> +
> +	return 0;
> +}
> +
> +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;
> +	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;
> +
> +	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;
> +
> +	kxcjk1013_acpi_gpio_probe(client, data);
> +
> +	if (client->irq < 0) {

<= 0?

> +		kxcjk1013_chip_setup_interrupt(data, false);
> +		goto skip_setup_trigger;
> +	}
> +
> +	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, NULL,
> +			kxcjk1013_trigger_handler, NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +		goto err_trigger_unregister;
> +	}
> +
> +skip_setup_trigger:
> +	ret = devm_iio_device_register(&client->dev, indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "unable to register iio device\n");
> +		if (data->trig_mode)
> +			goto err_buffer_cleanup;
> +		else
> +			return ret;
> +	}
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +err_trigger_unregister:
> +	iio_trigger_unregister(trig);
> +err_trigger_free:
> +	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 SIMPLE_DEV_PM_OPS(kxcjk1013_pm_ops, kxcjk1013_suspend, NULL);
> +#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 <srinivas.pandruvada@linux.intel.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("KXCJK1013 accelerometer driver");
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

Re: [PATCH] iio: accel: kxcjk1013 3-axis accelerometer driver

[Srinivas Pandruvada]

Thanks. Submitted new version. Only one question in-line.

On 06/04/2014 12:10 AM, Peter Meerwald wrote:
>
>> 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
>
> looks like a Freescale part (from the register layout)

If you know the part number, we can add in the config description for 
compatibility.

>
> comments inline
>
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 1e120fa..12addf2 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -77,4 +77,16 @@ config MMA8452
>>   	  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
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index dc0e379..4d153be 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -14,3 +14,5 @@ st_accel-$(CONFIG_IIO_BUFFER) += st_accel_buffer.o
>>
>>   obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
>>   obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
>> +
>> +obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
>> diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
>> new file mode 100644
>> index 0000000..299d441
>> --- /dev/null
>> +++ b/drivers/iio/accel/kxcjk-1013.c
>> @@ -0,0 +1,720 @@
>> +/*
>> + * 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/of.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>
>> +
>> +#define KXCJK1013_DRV_NAME "kxcjk1013"
>> +#define KXCJK1013_IRQ_NAME "kxcjk1013_event"
>> +
>> +#define KXCJK1013_REG_XOUT_L		0x06
>> +#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
>
> all these (_L, _H) are not really used
>
>> +#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	100000
>
> time unit?
>
>> +
>> +struct kxcjk1013_data {
>> +	struct i2c_client *client;
>> +	struct iio_trigger *trig;
>> +	bool	trig_mode;
>> +	struct mutex mutex;
>> +	s16 buffer[3];
>> +	atomic_t power_state;
>> +	int gpio_irq;
>> +	u8 odr_bits;
>> +};
>> +
>> +enum kxcjk1013_axis {
>> +	AXIS_X,
>> +	AXIS_Y,
>> +	AXIS_Z,
>> +};
>> +
>> +enum kxcjk1013_mode {
>> +	STANDBY,
>> +	OPERATION,
>> +};
>> +
>> +struct {
>> +	int val;
>> +	int val2;
>> +	int odr_bits;
>> +} samp_freq_table[] = { {0, 781, 0x08}, {1, 563, 0x09}, {3, 125, 0x0A},
>> +			{6, 25, 0x0B}, {12, 5, 0}, {25, 0, 0x01},
>> +			{50, 0, 0x02}, {100, 0, 0x03}, {200, 0, 0x04},
>> +			{400, 0, 0x05}, {800, 0, 0x06}, {1600, 0, 0x07} };
>
> static const
>
>> +
>> +/* Refer to section 4 of the specification */
>> +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 const
>
>> +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_setup_polarity(struct kxcjk1013_data *data,
>> +					  bool active_high)
>> +{
>> +	int 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 (active_high)
>> +		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 ret;
>> +}
>
> newline
>
>> +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 = 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;
>> +	}
>
> reg_ctrl1 not used
>
>> +
>> +	ret = kxcjk1013_set_mode(data, STANDBY);
>
> return value not checked
>
>> +
>> +	/* 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;
>> +	}
>> +
> extra newline
>> +
>> +	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;
>> +
>> +	/* Active high interrupt */
>> +	ret = kxcjk1013_chip_setup_polarity(data, true);
>
> return kxcjk1013_chip_setup_polarity(...)
>> +
>> +	return ret;
>> +}
>> +
>> +static int kxcjk1013_chip_setup_interrupt(struct kxcjk1013_data *data,
>> +					  bool status)
>> +{
>> +	int ret;
>> +
>> +	kxcjk1013_set_mode(data, STANDBY);
>> +
>> +	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; 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 / 1000);
>> +	if (odr_bits < 0)
>> +		return odr_bits;
>> +
>> +	kxcjk1013_set_mode(data, STANDBY);
>> +
>> +	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;
>> +
>> +	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 * 1000;
>> +			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;
>> +}
>> +
>> +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;
>> +
>> +			kxcjk1013_set_mode(data, OPERATION);
> return value?
>> +			atomic_inc(&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);
>
> val / 1000
>
>> +			ret = kxcjk1013_get_acc_reg(data, chan->scan_index);
>> +			if (atomic_dec_and_test(&data->power_state))
>> +				kxcjk1013_set_mode(data, STANDBY);
>> +		}
>> +		mutex_unlock(&data->mutex);
>> +
>> +		if (ret < 0)
>> +			return ret;
>> +
>> +		*val = (s16)ret >> chan->scan_type.shift;
>
> maybe sign_extend32?
>
>> +		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 IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
>> +		"0.781 1.563 3.125 6.25 12.5 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 seems to be 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,
>> +	.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);
>> +	int64_t time_ns = iio_get_time_ns();
>> +	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, time_ns);
>> +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);
>> +
>> +	if (state) {
>> +		kxcjk1013_chip_setup_interrupt(data, true);
>> +		kxcjk1013_set_mode(data, OPERATION);
>> +		atomic_inc(&data->power_state);
>> +	} else {
>> +		if (!atomic_dec_and_test(&data->power_state))
>> +			return 0;
>> +		kxcjk1013_chip_setup_interrupt(data, false);
>> +		kxcjk1013_set_mode(data, STANDBY);
>> +	}
>> +
>> +	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;
> remove newline
>> +
>> +	if (!ACPI_HANDLE(dev))
>> +		return -ENODEV;
>> +
>> +	id = acpi_match_device(dev->driver->acpi_match_table, dev);
> remove newline
>> +
>> +	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);
>
> remove newline
>> +
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = gpiod_to_irq(gpio);
>> +
> remove newline
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	data->gpio_irq = ret;
>> +
>> +	/* Update client irq if its invalid */
>
> it's
>
>> +	if (client->irq < 0)
>> +		client->irq = data->gpio_irq;
>
> client->irq > 0 is valid, so should be
> if (client->irq <= 0) ...
>
> (not sure)
>
>> +
>> +	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio),
>> +							data->gpio_irq);
>> +
>> +	return 0;
>> +}
>> +
>> +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;
>> +	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;
>> +
>> +	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;
>> +
>> +	kxcjk1013_acpi_gpio_probe(client, data);
>> +
>> +	if (client->irq < 0) {
>
> <= 0?
>
>> +		kxcjk1013_chip_setup_interrupt(data, false);
>> +		goto skip_setup_trigger;
>> +	}
>> +
>> +	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, NULL,
>> +			kxcjk1013_trigger_handler, NULL);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
>> +		goto err_trigger_unregister;
>> +	}
>> +
>> +skip_setup_trigger:
>> +	ret = devm_iio_device_register(&client->dev, indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "unable to register iio device\n");
>> +		if (data->trig_mode)
>> +			goto err_buffer_cleanup;
>> +		else
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_buffer_cleanup:
>> +	iio_triggered_buffer_cleanup(indio_dev);
>> +err_trigger_unregister:
>> +	iio_trigger_unregister(trig);
>> +err_trigger_free:
>> +	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 SIMPLE_DEV_PM_OPS(kxcjk1013_pm_ops, kxcjk1013_suspend, NULL);
>> +#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 <srinivas.pandruvada@linux.intel.com>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("KXCJK1013 accelerometer driver");
>>
>
Thanks,
Srinivas