Re: [PATCH v3 1/2] iio:gyro:bmg160 Gyro Sensor driver

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

On 08/07/2014 03:39 AM, Jonathan Cameron wrote:
> On 05/08/14 22:57, Srinivas Pandruvada wrote:
>> This change implements support for BMG160 Gyro sensor. Although chip
>> has several advanced features, this change implements minimum set
>> required for using gyro sensor.
>>
>> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> One more query.  In the write_raw function you always enable then suspend the
> device.  The enable is safe, but if you have a write to the attributes
> whilst operating in triggered / buffered mode will it not disable the
> device?  It is perfectly permissible to ignore such a write (return -EBUSY)
> but I don't think you are doing so.
>

I tested this. When trigger/events are active then first call to 
bmg160_set_power_state will increment runtime pm refcount and also 
execute runtime resume to change the mode to NORMAL.
But when write_raw is called while the trigger/events are active the 
runtime PM refcount is incremented since it was already more than 0, so 
the resume is not actually called. When at the end of write_raw 
bmg160_set_power_state to turn off, the ref count is simply decremented, 
but since it is not zero, runtime suspend will not be called.

Thanks,
Srinivas

> Otherwise, looks good to me.  Nice explanatory comments as well!
>> ---
>>   drivers/iio/gyro/Kconfig  |   11 +
>>   drivers/iio/gyro/Makefile |    1 +
>>   drivers/iio/gyro/bmg160.c | 1211 +++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 1223 insertions(+)
>>   create mode 100644 drivers/iio/gyro/bmg160.c
>>
>> diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
>> index ac2d69e..d630ae9 100644
>> --- a/drivers/iio/gyro/Kconfig
>> +++ b/drivers/iio/gyro/Kconfig
>> @@ -50,6 +50,17 @@ config ADXRS450
>>   	  This driver can also be built as a module.  If so, the module
>>   	  will be called adxrs450.
>>
>> +config BMG160
>> +	tristate "BOSCH BMG160 Gyro Sensor"
>> +	depends on I2C
>> +	select IIO_TRIGGERED_BUFFER if IIO_BUFFER
>> +	help
>> +	  Say yes here to build support for Bosch BMG160 Tri-axis Gyro Sensor
>> +	  driver.
>> +
>> +	  This driver can also be built as a module.  If so, the module
>> +	  will be called bmg160.
>> +
>>   config HID_SENSOR_GYRO_3D
>>   	depends on HID_SENSOR_HUB
>>   	select IIO_BUFFER
>> diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile
>> index 2f2752a..36a3877 100644
>> --- a/drivers/iio/gyro/Makefile
>> +++ b/drivers/iio/gyro/Makefile
>> @@ -8,6 +8,7 @@ obj-$(CONFIG_ADIS16130) += adis16130.o
>>   obj-$(CONFIG_ADIS16136) += adis16136.o
>>   obj-$(CONFIG_ADIS16260) += adis16260.o
>>   obj-$(CONFIG_ADXRS450) += adxrs450.o
>> +obj-$(CONFIG_BMG160) += bmg160.o
>>
>>   obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
>>
>> diff --git a/drivers/iio/gyro/bmg160.c b/drivers/iio/gyro/bmg160.c
>> new file mode 100644
>> index 0000000..80f92a6
>> --- /dev/null
>> +++ b/drivers/iio/gyro/bmg160.c
>> @@ -0,0 +1,1211 @@
>> +/*
>> + * BMG160 Gyro Sensor 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/slab.h>
>> +#include <linux/acpi.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/pm.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/events.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +
>> +#define BMG160_DRV_NAME		"bmg160"
>> +#define BMG160_IRQ_NAME		"bmg160_event"
>> +#define BMG160_GPIO_NAME		"gpio_int"
>> +
>> +#define BMG160_REG_CHIP_ID		0x00
>> +#define BMG160_CHIP_ID_VAL		0x0F
>> +
>> +#define BMG160_REG_PMU_LPW		0x11
>> +#define BMG160_MODE_NORMAL		0x00
>> +#define BMG160_MODE_DEEP_SUSPEND	0x20
>> +#define BMG160_MODE_SUSPEND		0x80
>> +
>> +#define BMG160_REG_RANGE		0x0F
>> +
>> +#define BMG160_RANGE_2000DPS		0
>> +#define BMG160_RANGE_1000DPS		1
>> +#define BMG160_RANGE_500DPS		2
>> +#define BMG160_RANGE_250DPS		3
>> +#define BMG160_RANGE_125DPS		4
>> +
>> +#define BMG160_REG_PMU_BW		0x10
>> +#define BMG160_NO_FILTER		0
>> +#define BMG160_DEF_BW			100
>> +
>> +#define BMG160_REG_INT_MAP_0		0x17
>> +#define BMG160_INT_MAP_0_BIT_ANY	BIT(1)
>> +
>> +#define BMG160_REG_INT_MAP_1		0x18
>> +#define BMG160_INT_MAP_1_BIT_NEW_DATA	BIT(0)
>> +
>> +#define BMG160_REG_INT_RST_LATCH	0x21
>> +#define BMG160_INT_MODE_LATCH_RESET	0x80
>> +#define BMG160_INT_MODE_LATCH_INT	0x0F
>> +#define BMG160_INT_MODE_NON_LATCH_INT	0x00
>> +
>> +#define BMG160_REG_INT_EN_0		0x15
>> +#define BMG160_DATA_ENABLE_INT		BIT(7)
>> +
>> +#define BMG160_REG_XOUT_L		0x02
>> +#define BMG160_AXIS_TO_REG(axis)	(BMG160_REG_XOUT_L + (axis * 2))
>> +
>> +#define BMG160_REG_SLOPE_THRES		0x1B
>> +#define BMG160_SLOPE_THRES_MASK	0x0F
>> +
>> +#define BMG160_REG_MOTION_INTR		0x1C
>> +#define BMG160_INT_MOTION_X		BIT(0)
>> +#define BMG160_INT_MOTION_Y		BIT(1)
>> +#define BMG160_INT_MOTION_Z		BIT(2)
>> +#define BMG160_ANY_DUR_MASK		0x30
>> +#define BMG160_ANY_DUR_SHIFT		4
>> +
>> +#define BMG160_REG_INT_STATUS_2	0x0B
>> +#define BMG160_ANY_MOTION_MASK		0x07
>> +
>> +#define BMG160_REG_TEMP		0x08
>> +#define BMG160_TEMP_CENTER_VAL		23
>> +
>> +#define BMG160_MAX_STARTUP_TIME_MS	80
>> +
>> +#define BMG160_AUTO_SUSPEND_DELAY_MS	2000
>> +
>> +struct bmg160_data {
>> +	struct i2c_client *client;
>> +	struct iio_trigger *dready_trig;
>> +	struct iio_trigger *motion_trig;
>> +	struct mutex mutex;
>> +	s16 buffer[8];
>> +	u8 bw_bits;
>> +	u32 dps_range;
>> +	int ev_enable_state;
>> +	int slope_thres;
>> +	bool dready_trigger_on;
>> +	bool motion_trigger_on;
>> +	int64_t timestamp;
>> +};
>> +
>> +enum bmg160_axis {
>> +	AXIS_X,
>> +	AXIS_Y,
>> +	AXIS_Z,
>> +};
>> +
>> +static const struct {
>> +	int val;
>> +	int bw_bits;
>> +} bmg160_samp_freq_table[] = { {100, 0x07},
>> +			       {200, 0x06},
>> +			       {400, 0x03},
>> +			       {1000, 0x02},
>> +			       {2000, 0x01} };
>> +
>> +static const struct {
>> +	int scale;
>> +	int dps_range;
>> +} bmg160_scale_table[] = { { 1065, BMG160_RANGE_2000DPS},
>> +			   { 532, BMG160_RANGE_1000DPS},
>> +			   { 266, BMG160_RANGE_500DPS},
>> +			   { 133, BMG160_RANGE_250DPS},
>> +			   { 66, BMG160_RANGE_125DPS} };
>> +
>> +static int bmg160_set_mode(struct bmg160_data *data, u8 mode)
>> +{
>> +	int ret;
>> +
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_PMU_LPW, mode);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_pmu_lpw\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_convert_freq_to_bit(int val)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(bmg160_samp_freq_table); ++i) {
>> +		if (bmg160_samp_freq_table[i].val == val)
>> +			return bmg160_samp_freq_table[i].bw_bits;
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int bmg160_set_bw(struct bmg160_data *data, int val)
>> +{
>> +	int ret;
>> +	int bw_bits;
>> +
>> +	bw_bits = bmg160_convert_freq_to_bit(val);
>> +	if (bw_bits < 0)
>> +		return bw_bits;
>> +
>> +	ret = i2c_smbus_write_byte_data(data->client, BMG160_REG_PMU_BW,
>> +					bw_bits);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_pmu_bw\n");
>> +		return ret;
>> +	}
>> +
>> +	data->bw_bits = bw_bits;
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_chip_init(struct bmg160_data *data)
>> +{
>> +	int ret;
>> +
>> +	ret = i2c_smbus_read_byte_data(data->client, BMG160_REG_CHIP_ID);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_chip_id\n");
>> +		return ret;
>> +	}
>> +
>> +	dev_dbg(&data->client->dev, "Chip Id %x\n", ret);
>> +	if (ret != BMG160_CHIP_ID_VAL) {
>> +		dev_err(&data->client->dev, "invalid chip %x\n", ret);
>> +		return -ENODEV;
>> +	}
>> +
>> +	ret = bmg160_set_mode(data, BMG160_MODE_NORMAL);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* Wait upto 500 ms to be ready after changing mode */
>> +	usleep_range(500, 1000);
>> +
>> +	/* Set Bandwidth */
>> +	ret = bmg160_set_bw(data, BMG160_DEF_BW);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* Set Default Range */
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_RANGE,
>> +					BMG160_RANGE_500DPS);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_range\n");
>> +		return ret;
>> +	}
>> +	data->dps_range = BMG160_RANGE_500DPS;
>> +
>> +	ret = i2c_smbus_read_byte_data(data->client, BMG160_REG_SLOPE_THRES);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_slope_thres\n");
>> +		return ret;
>> +	}
>> +	data->slope_thres = ret;
>> +
>> +	/* Set default interrupt mode */
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_INT_RST_LATCH,
>> +					BMG160_INT_MODE_LATCH_INT |
>> +					BMG160_INT_MODE_LATCH_RESET);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev,
>> +			"Error writing reg_motion_intr\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_set_power_state(struct bmg160_data *data, bool on)
>> +{
>> +	int ret;
>> +
>> +	if (on)
>> +		ret = pm_runtime_get_sync(&data->client->dev);
>> +	else {
>> +		pm_runtime_mark_last_busy(&data->client->dev);
>> +		ret = pm_runtime_put_autosuspend(&data->client->dev);
>> +	}
>> +
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev,
>> +			"Failed: bmg160_set_power_state for %d\n", on);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_setup_any_motion_interrupt(struct bmg160_data *data,
>> +					     bool status)
>> +{
>> +	int ret;
>> +
>> +	/* Enable/Disable INT_MAP0 mapping */
>> +	ret = i2c_smbus_read_byte_data(data->client,  BMG160_REG_INT_MAP_0);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_int_map0\n");
>> +		return ret;
>> +	}
>> +	if (status)
>> +		ret |= BMG160_INT_MAP_0_BIT_ANY;
>> +	else
>> +		ret &= ~BMG160_INT_MAP_0_BIT_ANY;
>> +
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_INT_MAP_0,
>> +					ret);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_int_map0\n");
>> +		return ret;
>> +	}
>> +
>> +	/* Enable/Disable slope interrupts */
>> +	if (status) {
>> +		/* Update slope thres */
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_SLOPE_THRES,
>> +						data->slope_thres);
>> +		if (ret < 0) {
>> +			dev_err(&data->client->dev,
>> +				"Error writing reg_slope_thres\n");
>> +			return ret;
>> +		}
>> +
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_MOTION_INTR,
>> +						BMG160_INT_MOTION_X |
>> +						BMG160_INT_MOTION_Y |
>> +						BMG160_INT_MOTION_Z);
>> +		if (ret < 0) {
>> +			dev_err(&data->client->dev,
>> +				"Error writing reg_motion_intr\n");
>> +			return ret;
>> +		}
>> +
>> +		/*
>> +		 * New data interrupt is always non-latched,
>> +		 * which will have higher priority, so no need
>> +		 * to set latched mode, we will be flooded anyway with INTR
>> +		 */
>> +		if (!data->dready_trigger_on) {
>> +			ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_RST_LATCH,
>> +						BMG160_INT_MODE_LATCH_INT |
>> +						BMG160_INT_MODE_LATCH_RESET);
>> +			if (ret < 0) {
>> +				dev_err(&data->client->dev,
>> +					"Error writing reg_rst_latch\n");
>> +				return ret;
>> +			}
>> +		}
>> +
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_EN_0,
>> +						BMG160_DATA_ENABLE_INT);
>> +
>> +	} else
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_EN_0,
>> +						0);
>> +
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_int_en0\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_setup_new_data_interrupt(struct bmg160_data *data,
>> +					   bool status)
>> +{
>> +	int ret;
>> +
>> +	/* Enable/Disable INT_MAP1 mapping */
>> +	ret = i2c_smbus_read_byte_data(data->client, BMG160_REG_INT_MAP_1);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_int_map1\n");
>> +		return ret;
>> +	}
>> +
>> +	if (status)
>> +		ret |= BMG160_INT_MAP_1_BIT_NEW_DATA;
>> +	else
>> +		ret &= ~BMG160_INT_MAP_1_BIT_NEW_DATA;
>> +
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_INT_MAP_1,
>> +					ret);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_int_map1\n");
>> +		return ret;
>> +	}
>> +
>> +	if (status) {
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_RST_LATCH,
>> +						BMG160_INT_MODE_NON_LATCH_INT |
>> +						BMG160_INT_MODE_LATCH_RESET);
>> +		if (ret < 0) {
>> +			dev_err(&data->client->dev,
>> +				"Error writing reg_rst_latch\n");
>> +				return ret;
>> +		}
>> +
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_EN_0,
>> +						BMG160_DATA_ENABLE_INT);
>> +
>> +	} else {
>> +		/* Restore interrupt mode */
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_RST_LATCH,
>> +						BMG160_INT_MODE_LATCH_INT |
>> +						BMG160_INT_MODE_LATCH_RESET);
>> +		if (ret < 0) {
>> +			dev_err(&data->client->dev,
>> +				"Error writing reg_rst_latch\n");
>> +				return ret;
>> +		}
>> +
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +						BMG160_REG_INT_EN_0,
>> +						0);
>> +	}
>> +
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_int_en0\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_get_bw(struct bmg160_data *data, int *val)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(bmg160_samp_freq_table); ++i) {
>> +		if (bmg160_samp_freq_table[i].bw_bits == data->bw_bits) {
>> +			*val = bmg160_samp_freq_table[i].val;
>> +			return IIO_VAL_INT;
>> +		}
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int bmg160_set_scale(struct bmg160_data *data, int val)
>> +{
>> +	int ret, i;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(bmg160_scale_table); ++i) {
>> +		if (bmg160_scale_table[i].scale == val) {
>> +			ret = i2c_smbus_write_byte_data(
>> +					data->client,
>> +					BMG160_REG_RANGE,
>> +					bmg160_scale_table[i].dps_range);
>> +			if (ret < 0) {
>> +				dev_err(&data->client->dev,
>> +					"Error writing reg_range\n");
>> +				return ret;
>> +			}
>> +			data->dps_range = bmg160_scale_table[i].dps_range;
>> +			return 0;
>> +		}
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int bmg160_get_temp(struct bmg160_data *data, int *val)
>> +{
>> +	int ret;
>> +
>> +	mutex_lock(&data->mutex);
>> +	ret = bmg160_set_power_state(data, true);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	ret = i2c_smbus_read_byte_data(data->client, BMG160_REG_TEMP);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_temp\n");
>> +		bmg160_set_power_state(data, false);
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	*val = sign_extend32(ret, 7);
>> +	ret = bmg160_set_power_state(data, false);
>> +	mutex_unlock(&data->mutex);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return IIO_VAL_INT;
>> +}
>> +
>> +static int bmg160_get_axis(struct bmg160_data *data, int axis, int *val)
>> +{
>> +	int ret;
>> +
>> +	mutex_lock(&data->mutex);
>> +	ret = bmg160_set_power_state(data, true);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	ret = i2c_smbus_read_word_data(data->client, BMG160_AXIS_TO_REG(axis));
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading axis %d\n", axis);
>> +		bmg160_set_power_state(data, false);
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	*val = sign_extend32(ret, 15);
>> +	ret = bmg160_set_power_state(data, false);
>> +	mutex_unlock(&data->mutex);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return IIO_VAL_INT;
>> +}
>> +
>> +static int bmg160_read_raw(struct iio_dev *indio_dev,
>> +			   struct iio_chan_spec const *chan,
>> +			   int *val, int *val2, long mask)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		switch (chan->type) {
>> +		case IIO_TEMP:
>> +			return bmg160_get_temp(data, val);
>> +		case IIO_ANGL_VEL:
>> +			if (iio_buffer_enabled(indio_dev))
>> +				return -EBUSY;
>> +			else
>> +				return bmg160_get_axis(data, chan->scan_index,
>> +						       val);
>> +		default:
>> +			return -EINVAL;
>> +		}
>> +	case IIO_CHAN_INFO_OFFSET:
>> +		if (chan->type == IIO_TEMP) {
>> +			*val = BMG160_TEMP_CENTER_VAL;
>> +			return IIO_VAL_INT;
>> +		} else
>> +			return -EINVAL;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		*val = 0;
>> +		switch (chan->type) {
>> +		case IIO_TEMP:
>> +			*val2 = 500000;
>> +			return IIO_VAL_INT_PLUS_MICRO;
>> +		case IIO_ANGL_VEL:
>> +		{
>> +			int i;
>> +
>> +			for (i = 0; i < ARRAY_SIZE(bmg160_scale_table); ++i) {
>> +				if (bmg160_scale_table[i].dps_range ==
>> +							data->dps_range) {
>> +					*val2 = bmg160_scale_table[i].scale;
>> +					return IIO_VAL_INT_PLUS_MICRO;
>> +				}
>> +			}
>> +			return -EINVAL;
>> +		}
>> +		default:
>> +			return -EINVAL;
>> +		}
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		*val2 = 0;
>> +		mutex_lock(&data->mutex);
>> +		ret = bmg160_get_bw(data, val);
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static int bmg160_write_raw(struct iio_dev *indio_dev,
>> +			    struct iio_chan_spec const *chan,
>> +			    int val, int val2, long mask)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		mutex_lock(&data->mutex);
>> +		/*
>> +		 * Section 4.2 of spec
>> +		 * In suspend mode, the only supported operations are reading
>> +		 * registers as well as writing to the (0x14) softreset
>> +		 * register. Since we will be in suspend mode by default, change
>> +		 * mode to power on for other writes.
>> +		 */
>> +		ret = bmg160_set_power_state(data, true);
>> +		if (ret < 0) {
>> +			mutex_unlock(&data->mutex);
>> +			return ret;
>> +		}
>> +		ret = bmg160_set_bw(data, val);
>> +		if (ret < 0) {
>> +			bmg160_set_power_state(data, false);
>> +			mutex_unlock(&data->mutex);
>> +			return ret;
>> +		}
>> +		ret = bmg160_set_power_state(data, false);
> Could this end up disabling the part when in triggered mode?
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		if (val)
>> +			return -EINVAL;
>> +
>> +		mutex_lock(&data->mutex);
>> +		/* Refer to comments above for the suspend mode ops */
>> +		ret = bmg160_set_power_state(data, true);
>> +		if (ret < 0) {
>> +			mutex_unlock(&data->mutex);
>> +			return ret;
>> +		}
>> +		ret = bmg160_set_scale(data, val2);
>> +		if (ret < 0) {
>> +			bmg160_set_power_state(data, false);
>> +			mutex_unlock(&data->mutex);
>> +			return ret;
>> +		}
>> +		ret = bmg160_set_power_state(data, false);
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int bmg160_read_event(struct iio_dev *indio_dev,
>> +			     const struct iio_chan_spec *chan,
>> +			     enum iio_event_type type,
>> +			     enum iio_event_direction dir,
>> +			     enum iio_event_info info,
>> +			     int *val, int *val2)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	*val2 = 0;
>> +	switch (info) {
>> +	case IIO_EV_INFO_VALUE:
>> +		*val = data->slope_thres & BMG160_SLOPE_THRES_MASK;
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	return IIO_VAL_INT;
>> +}
>> +
>> +static int bmg160_write_event(struct iio_dev *indio_dev,
>> +			      const struct iio_chan_spec *chan,
>> +			      enum iio_event_type type,
>> +			      enum iio_event_direction dir,
>> +			      enum iio_event_info info,
>> +			      int val, int val2)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	switch (info) {
>> +	case IIO_EV_INFO_VALUE:
>> +		if (data->ev_enable_state)
>> +			return -EBUSY;
>> +		data->slope_thres &= ~BMG160_SLOPE_THRES_MASK;
>> +		data->slope_thres |= (val & BMG160_SLOPE_THRES_MASK);
>> +		break;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_read_event_config(struct iio_dev *indio_dev,
>> +				    const struct iio_chan_spec *chan,
>> +				    enum iio_event_type type,
>> +				    enum iio_event_direction dir)
>> +{
>> +
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	return data->ev_enable_state;
>> +}
>> +
>> +static int bmg160_write_event_config(struct iio_dev *indio_dev,
>> +				     const struct iio_chan_spec *chan,
>> +				     enum iio_event_type type,
>> +				     enum iio_event_direction dir,
>> +				     int state)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	if (state && data->ev_enable_state)
>> +		return 0;
>> +
>> +	mutex_lock(&data->mutex);
>> +
>> +	if (!state && data->motion_trigger_on) {
>> +		data->ev_enable_state = 0;
>> +		mutex_unlock(&data->mutex);
>> +		return 0;
>> +	}
>> +	/*
>> +	 * We will expect the enable and disable to do operation in
>> +	 * in reverse order. This will happen here anyway as our
>> +	 * resume operation uses sync mode runtime pm calls, the
>> +	 * suspend operation will be delayed by autosuspend delay
>> +	 * So the disable operation will still happen in reverse of
>> +	 * enable operation. When runtime pm is disabled the mode
>> +	 * is always on so sequence doesn't matter
>> +	 */
> Thanks for the detailed comment!
>> +	ret = bmg160_set_power_state(data, state);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	ret =  bmg160_setup_any_motion_interrupt(data, state);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +
>> +	data->ev_enable_state = state;
>> +	mutex_unlock(&data->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_validate_trigger(struct iio_dev *indio_dev,
>> +				   struct iio_trigger *trig)
>> +{
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	if (data->dready_trig != trig && data->motion_trig != trig)
>> +		return -EINVAL;
>> +
>> +	return 0;
>> +}
>> +
>> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 400 1000 2000");
>> +
>> +static IIO_CONST_ATTR(in_anglvel_scale_available,
>> +		      "0.001065 0.000532 0.000266 0.000133 0.000066");
>> +
>> +static struct attribute *bmg160_attributes[] = {
>> +	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
>> +	&iio_const_attr_in_anglvel_scale_available.dev_attr.attr,
>> +	NULL,
>> +};
>> +
>> +static const struct attribute_group bmg160_attrs_group = {
>> +	.attrs = bmg160_attributes,
>> +};
>> +
>> +static const struct iio_event_spec bmg160_event = {
>> +		.type = IIO_EV_TYPE_ROC,
>> +		.dir = IIO_EV_DIR_RISING | IIO_EV_DIR_FALLING,
>> +		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
>> +				       BIT(IIO_EV_INFO_ENABLE)
>> +};
>> +
>> +#define BMG160_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_SAMP_FREQ),	\
>> +	.scan_index = AXIS_##_axis,					\
>> +	.scan_type = {							\
>> +		.sign = 's',						\
>> +		.realbits = 16,					\
>> +		.storagebits = 16,					\
>> +	},								\
>> +	.event_spec = &bmg160_event,					\
>> +	.num_event_specs = 1						\
>> +}
>> +
>> +static const struct iio_chan_spec bmg160_channels[] = {
>> +	{
>> +		.type = IIO_TEMP,
>> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>> +				      BIT(IIO_CHAN_INFO_SCALE) |
>> +				      BIT(IIO_CHAN_INFO_OFFSET),
>> +		.scan_index = -1,
>> +	},
>> +	BMG160_CHANNEL(X),
>> +	BMG160_CHANNEL(Y),
>> +	BMG160_CHANNEL(Z),
>> +	IIO_CHAN_SOFT_TIMESTAMP(3),
>> +};
>> +
>> +static const struct iio_info bmg160_info = {
>> +	.attrs			= &bmg160_attrs_group,
>> +	.read_raw		= bmg160_read_raw,
>> +	.write_raw		= bmg160_write_raw,
>> +	.read_event_value	= bmg160_read_event,
>> +	.write_event_value	= bmg160_write_event,
>> +	.write_event_config	= bmg160_write_event_config,
>> +	.read_event_config	= bmg160_read_event_config,
>> +	.validate_trigger	= bmg160_validate_trigger,
>> +	.driver_module		= THIS_MODULE,
>> +};
>> +
>> +static irqreturn_t bmg160_trigger_handler(int irq, void *p)
>> +{
>> +	struct iio_poll_func *pf = p;
>> +	struct iio_dev *indio_dev = pf->indio_dev;
>> +	struct bmg160_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 = i2c_smbus_read_word_data(data->client,
>> +					       BMG160_AXIS_TO_REG(bit));
>> +		if (ret < 0) {
>> +			mutex_unlock(&data->mutex);
>> +			goto err;
>> +		}
>> +		data->buffer[i++] = ret;
>> +	}
>> +	mutex_unlock(&data->mutex);
>> +
>> +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
>> +					   data->timestamp);
>> +err:
>> +	iio_trigger_notify_done(indio_dev->trig);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int bmg160_trig_try_reen(struct iio_trigger *trig)
>> +{
>> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	/* new data interrupts don't need ack */
>> +	if (data->dready_trigger_on)
>> +		return 0;
>> +
>> +	/* Set latched mode interrupt and clear any latched interrupt */
>> +	ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_INT_RST_LATCH,
>> +					BMG160_INT_MODE_LATCH_INT |
>> +					BMG160_INT_MODE_LATCH_RESET);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error writing reg_rst_latch\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_data_rdy_trigger_set_state(struct iio_trigger *trig,
>> +					     bool state)
>> +{
>> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	mutex_lock(&data->mutex);
>> +
>> +	if (!state && data->ev_enable_state && data->motion_trigger_on) {
>> +		data->motion_trigger_on = false;
>> +		mutex_unlock(&data->mutex);
>> +		return 0;
>> +	}
>> +
>> +	/*
>> +	 * Refer to comment in bmg160_write_event_config for
>> +	 * enable/disable operation order
>> +	 */
>> +	ret = bmg160_set_power_state(data, state);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +	if (data->motion_trig == trig)
>> +		ret =  bmg160_setup_any_motion_interrupt(data, state);
>> +	else
>> +		ret = bmg160_setup_new_data_interrupt(data, state);
>> +	if (ret < 0) {
>> +		mutex_unlock(&data->mutex);
>> +		return ret;
>> +	}
>> +	if (data->motion_trig == trig)
>> +		data->motion_trigger_on = state;
>> +	else
>> +		data->dready_trigger_on = state;
>> +
>> +	mutex_unlock(&data->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct iio_trigger_ops bmg160_trigger_ops = {
>> +	.set_trigger_state = bmg160_data_rdy_trigger_set_state,
>> +	.try_reenable = bmg160_trig_try_reen,
>> +	.owner = THIS_MODULE,
>> +};
>> +
>> +static irqreturn_t bmg160_event_handler(int irq, void *private)
>> +{
>> +	struct iio_dev *indio_dev = private;
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +	int dir;
>> +
>> +	ret = i2c_smbus_read_byte_data(data->client, BMG160_REG_INT_STATUS_2);
>> +	if (ret < 0) {
>> +		dev_err(&data->client->dev, "Error reading reg_int_status2\n");
>> +		goto ack_intr_status;
>> +	}
>> +
>> +	if (ret & 0x08)
>> +		dir = IIO_EV_DIR_RISING;
>> +	else
>> +		dir = IIO_EV_DIR_FALLING;
>> +
>> +	if (ret & BMG160_ANY_MOTION_MASK)
>> +		iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ANGL_VEL,
>> +							0,
>> +							IIO_MOD_X_OR_Y_OR_Z,
>> +							IIO_EV_TYPE_ROC,
>> +							dir),
>> +							data->timestamp);
>> +
>> +ack_intr_status:
>> +	if (!data->dready_trigger_on) {
>> +		ret = i2c_smbus_write_byte_data(data->client,
>> +					BMG160_REG_INT_RST_LATCH,
>> +					BMG160_INT_MODE_LATCH_INT |
>> +					BMG160_INT_MODE_LATCH_RESET);
>> +		if (ret < 0)
>> +			dev_err(&data->client->dev,
>> +				"Error writing reg_rst_latch\n");
>> +	}
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t bmg160_data_rdy_trig_poll(int irq, void *private)
>> +{
>> +	struct iio_dev *indio_dev = private;
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	data->timestamp = iio_get_time_ns();
>> +
>> +	if (data->dready_trigger_on)
>> +		iio_trigger_poll(data->dready_trig);
>> +	else if (data->motion_trigger_on)
>> +		iio_trigger_poll(data->motion_trig);
>> +
>> +	if (data->ev_enable_state)
>> +		return IRQ_WAKE_THREAD;
>> +	else
>> +		return IRQ_HANDLED;
>> +
>> +}
>> +
>> +static int bmg160_acpi_gpio_probe(struct i2c_client *client,
>> +				  struct bmg160_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, BMG160_GPIO_NAME, 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 bmg160_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	struct bmg160_data *data;
>> +	struct iio_dev *indio_dev;
>> +	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 = bmg160_chip_init(data);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	mutex_init(&data->mutex);
>> +
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->channels = bmg160_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(bmg160_channels);
>> +	indio_dev->name = BMG160_DRV_NAME;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->info = &bmg160_info;
>> +
>> +	if (client->irq <= 0)
>> +		client->irq = bmg160_acpi_gpio_probe(client, data);
>> +
>> +	if (client->irq > 0) {
>> +		ret = devm_request_threaded_irq(&client->dev,
>> +						client->irq,
>> +						bmg160_data_rdy_trig_poll,
>> +						bmg160_event_handler,
>> +						IRQF_TRIGGER_RISING,
>> +						BMG160_IRQ_NAME,
>> +						indio_dev);
>> +		if (ret)
>> +			return ret;
>> +
>> +		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
>> +							   "%s-dev%d",
>> +							   indio_dev->name,
>> +							   indio_dev->id);
>> +		if (!data->dready_trig)
>> +			return -ENOMEM;
>> +
>> +		data->motion_trig = devm_iio_trigger_alloc(&client->dev,
>> +							  "%s-any-motion-dev%d",
>> +							  indio_dev->name,
>> +							  indio_dev->id);
>> +		if (!data->motion_trig)
>> +			return -ENOMEM;
>> +
>> +		data->dready_trig->dev.parent = &client->dev;
>> +		data->dready_trig->ops = &bmg160_trigger_ops;
>> +		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
>> +		ret = iio_trigger_register(data->dready_trig);
>> +		if (ret)
>> +			return ret;
>> +
>> +		data->motion_trig->dev.parent = &client->dev;
>> +		data->motion_trig->ops = &bmg160_trigger_ops;
>> +		iio_trigger_set_drvdata(data->motion_trig, indio_dev);
>> +		ret = iio_trigger_register(data->motion_trig);
>> +		if (ret) {
>> +			data->motion_trig = NULL;
>> +			goto err_trigger_unregister;
>> +		}
>> +
>> +		ret = iio_triggered_buffer_setup(indio_dev,
>> +						 NULL,
>> +						 bmg160_trigger_handler,
>> +						 NULL);
>> +		if (ret < 0) {
>> +			dev_err(&client->dev,
>> +				"iio triggered buffer setup failed\n");
>> +			goto err_trigger_unregister;
>> +		}
>> +	}
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "unable to register iio device\n");
>> +		goto err_buffer_cleanup;
>> +	}
>> +
>> +	ret = pm_runtime_set_active(&client->dev);
>> +	if (ret)
>> +		goto err_iio_unregister;
>> +
>> +	pm_runtime_enable(&client->dev);
>> +	pm_runtime_set_autosuspend_delay(&client->dev,
>> +					 BMG160_AUTO_SUSPEND_DELAY_MS);
>> +	pm_runtime_use_autosuspend(&client->dev);
>> +
>> +	return 0;
>> +
>> +err_iio_unregister:
>> +	iio_device_unregister(indio_dev);
>> +err_buffer_cleanup:
>> +	if (data->dready_trig)
>> +		iio_triggered_buffer_cleanup(indio_dev);
>> +err_trigger_unregister:
>> +	if (data->dready_trig)
>> +		iio_trigger_unregister(data->dready_trig);
>> +	if (data->motion_trig)
>> +		iio_trigger_unregister(data->motion_trig);
>> +
>> +	return ret;
>> +}
>> +
>> +static int bmg160_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	pm_runtime_disable(&client->dev);
>> +	pm_runtime_set_suspended(&client->dev);
>> +	pm_runtime_put_noidle(&client->dev);
>> +
>> +	iio_device_unregister(indio_dev);
>> +
>> +	if (data->dready_trig) {
>> +		iio_triggered_buffer_cleanup(indio_dev);
>> +		iio_trigger_unregister(data->dready_trig);
>> +		iio_trigger_unregister(data->motion_trig);
>> +	}
>> +
>> +	mutex_lock(&data->mutex);
>> +	bmg160_set_mode(data, BMG160_MODE_DEEP_SUSPEND);
>> +	mutex_unlock(&data->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int bmg160_suspend(struct device *dev)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	mutex_lock(&data->mutex);
>> +	bmg160_set_mode(data, BMG160_MODE_SUSPEND);
>> +	mutex_unlock(&data->mutex);
>> +
>> +	return 0;
>> +}
>> +
>> +static int bmg160_resume(struct device *dev)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	mutex_lock(&data->mutex);
>> +	if (data->dready_trigger_on || data->motion_trigger_on ||
>> +							data->ev_enable_state)
>> +		bmg160_set_mode(data, BMG160_MODE_NORMAL);
>> +	mutex_unlock(&data->mutex);
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>> +#ifdef CONFIG_PM_RUNTIME
>> +static int bmg160_runtime_suspend(struct device *dev)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +
>> +	return bmg160_set_mode(data, BMG160_MODE_SUSPEND);
>> +}
>> +
>> +static int bmg160_runtime_resume(struct device *dev)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +	struct bmg160_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	ret = bmg160_set_mode(data, BMG160_MODE_NORMAL);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	msleep_interruptible(BMG160_MAX_STARTUP_TIME_MS);
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops bmg160_pm_ops = {
>> +	SET_SYSTEM_SLEEP_PM_OPS(bmg160_suspend, bmg160_resume)
>> +	SET_RUNTIME_PM_OPS(bmg160_runtime_suspend,
>> +			   bmg160_runtime_resume, NULL)
>> +};
>> +
>> +static const struct acpi_device_id bmg160_acpi_match[] = {
>> +	{"BMG0160", 0},
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(acpi, bmg160_acpi_match);
>> +
>> +static const struct i2c_device_id bmg160_id[] = {
>> +	{"bmg160", 0},
>> +	{}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(i2c, bmg160_id);
>> +
>> +static struct i2c_driver bmg160_driver = {
>> +	.driver = {
>> +		.name	= BMG160_DRV_NAME,
>> +		.acpi_match_table = ACPI_PTR(bmg160_acpi_match),
>> +		.pm	= &bmg160_pm_ops,
>> +	},
>> +	.probe		= bmg160_probe,
>> +	.remove		= bmg160_remove,
>> +	.id_table	= bmg160_id,
>> +};
>> +module_i2c_driver(bmg160_driver);
>> +
>> +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("BMG160 Gyro driver");
>>
>