[PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500

[PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500

[Jean-Baptiste Maneyrol]

Starting from MPU6500, accelerometer dlpf is set in a separate register
named ACCEL_CONFIG_2.
Add this new register in the map and set it for the corresponding chips.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 32 ++++++++++++++++++++++++++=
+---
 drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  3 +++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/i=
nv_mpu6050/inv_mpu_core.c
index 96dabbd..605b9da4 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -41,6 +41,7 @@
 static const struct inv_mpu6050_reg_map reg_set_6500 =3D {
 	.sample_rate_div	=3D INV_MPU6050_REG_SAMPLE_RATE_DIV,
 	.lpf                    =3D INV_MPU6050_REG_CONFIG,
+	.accel_lpf              =3D INV_MPU6500_REG_ACCEL_CONFIG_2,
 	.user_ctrl              =3D INV_MPU6050_REG_USER_CTRL,
 	.fifo_en                =3D INV_MPU6050_REG_FIFO_EN,
 	.gyro_config            =3D INV_MPU6050_REG_GYRO_CONFIG,
@@ -211,6 +212,32 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state=
 *st, bool power_on)
 EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
=20
 /**
+ *  inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip depen=
dent
+ *
+ *  MPU60xx/MPU9150 use only 1 register for accelerometer + gyroscope
+ *  MPU6500 and above have a dedicated register for accelerometer
+ */
+static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
+				    enum inv_mpu6050_filter_e val)
+{
+	int result;
+
+	result =3D regmap_write(st->map, st->reg->lpf, val);
+	if (result)
+		return result;
+
+	/* set accel lpf for chip >=3D MPU6500 */
+	if (st->chip_type !=3D INV_MPU6050 && st->chip_type !=3D INV_MPU6000 &&
+			st->chip_type !=3D INV_MPU9150) {
+		result =3D regmap_write(st->map, st->reg->accel_lpf, val);
+		if (result)
+			return result;
+	}
+
+	return 0;
+}
+
+/**
  *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
  *
  *  Initial configuration:
@@ -233,8 +260,7 @@ static int inv_mpu6050_init_config(struct iio_dev *indi=
o_dev)
 	if (result)
 		return result;
=20
-	d =3D INV_MPU6050_FILTER_20HZ;
-	result =3D regmap_write(st->map, st->reg->lpf, d);
+	result =3D inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
 	if (result)
 		return result;
=20
@@ -552,7 +578,7 @@ static int inv_mpu6050_set_lpf(struct inv_mpu6050_state=
 *st, int rate)
 	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
 		i++;
 	data =3D d[i];
-	result =3D regmap_write(st->map, st->reg->lpf, data);
+	result =3D inv_mpu6050_set_lpf_regs(st, data);
 	if (result)
 		return result;
 	st->chip_config.lpf =3D data;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/in=
v_mpu6050/inv_mpu_iio.h
index ef13de7..953a0c0 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -28,6 +28,7 @@
  *  struct inv_mpu6050_reg_map - Notable registers.
  *  @sample_rate_div:	Divider applied to gyro output rate.
  *  @lpf:		Configures internal low pass filter.
+ *  @accel_lpf:		Configures accelerometer low pass filter.
  *  @user_ctrl:		Enables/resets the FIFO.
  *  @fifo_en:		Determines which data will appear in FIFO.
  *  @gyro_config:	gyro config register.
@@ -47,6 +48,7 @@
 struct inv_mpu6050_reg_map {
 	u8 sample_rate_div;
 	u8 lpf;
+	u8 accel_lpf;
 	u8 user_ctrl;
 	u8 fifo_en;
 	u8 gyro_config;
@@ -188,6 +190,7 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_FIFO_THRESHOLD           500
=20
 /* mpu6500 registers */
+#define INV_MPU6500_REG_ACCEL_CONFIG_2      0x1D
 #define INV_MPU6500_REG_ACCEL_OFFSET        0x77
=20
 /* delay time in milliseconds */
--=20
1.9.1

Re: [PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500

[Jonathan Cameron]

On 16/05/17 14:12, Jean-Baptiste Maneyrol wrote:
> Starting from MPU6500, accelerometer dlpf is set in a separate register
> named ACCEL_CONFIG_2.
> Add this new register in the map and set it for the corresponding chips.
> 
> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Perhaps a fixes tag as we presumably want this to go to stable?  Can see some rather
unexpected results occurring without it.

Hmm. Question to follow up is should we split the ABI to allow separate control.
Ideally we probably should but technically it'd be an unnecessary userspace
interface change.  The question is whether we'd actually break anything?

I'd certainly prefer to see the two separate attributes to control the different
low pass filters.

Jonathan

> ---
>   drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 32 +++++++++++++++++++++++++++---
>   drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  3 +++
>   2 files changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 96dabbd..605b9da4 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -41,6 +41,7 @@
>   static const struct inv_mpu6050_reg_map reg_set_6500 = {
>   	.sample_rate_div	= INV_MPU6050_REG_SAMPLE_RATE_DIV,
>   	.lpf                    = INV_MPU6050_REG_CONFIG,
> +	.accel_lpf              = INV_MPU6500_REG_ACCEL_CONFIG_2,
>   	.user_ctrl              = INV_MPU6050_REG_USER_CTRL,
>   	.fifo_en                = INV_MPU6050_REG_FIFO_EN,
>   	.gyro_config            = INV_MPU6050_REG_GYRO_CONFIG,
> @@ -211,6 +212,32 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
>   EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
>   
>   /**
> + *  inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip dependent
> + *
> + *  MPU60xx/MPU9150 use only 1 register for accelerometer + gyroscope
> + *  MPU6500 and above have a dedicated register for accelerometer
> + */
> +static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
> +				    enum inv_mpu6050_filter_e val)
> +{
> +	int result;
> +
> +	result = regmap_write(st->map, st->reg->lpf, val);
> +	if (result)
> +		return result;
> +
> +	/* set accel lpf for chip >= MPU6500 */
> +	if (st->chip_type != INV_MPU6050 && st->chip_type != INV_MPU6000 &&
> +			st->chip_type != INV_MPU9150) {
I'd prefer a switch for this as it'll end up slightly easier to follow
> +		result = regmap_write(st->map, st->reg->accel_lpf, val);
> +		if (result)
> +			return result;
return directly
> +	}
> +
> +	return 0;
> +}
> +
> +/**
>    *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
>    *
>    *  Initial configuration:
> @@ -233,8 +260,7 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
>   	if (result)
>   		return result;
>   
> -	d = INV_MPU6050_FILTER_20HZ;
> -	result = regmap_write(st->map, st->reg->lpf, d);
> +	result = inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
>   	if (result)
>   		return result;
>   
> @@ -552,7 +578,7 @@ static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
>   	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
>   		i++;
>   	data = d[i];
> -	result = regmap_write(st->map, st->reg->lpf, data);
> +	result = inv_mpu6050_set_lpf_regs(st, data);
>   	if (result)
>   		return result;
>   	st->chip_config.lpf = data;
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> index ef13de7..953a0c0 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> @@ -28,6 +28,7 @@
>    *  struct inv_mpu6050_reg_map - Notable registers.
>    *  @sample_rate_div:	Divider applied to gyro output rate.
>    *  @lpf:		Configures internal low pass filter.
> + *  @accel_lpf:		Configures accelerometer low pass filter.
>    *  @user_ctrl:		Enables/resets the FIFO.
>    *  @fifo_en:		Determines which data will appear in FIFO.
>    *  @gyro_config:	gyro config register.
> @@ -47,6 +48,7 @@
>   struct inv_mpu6050_reg_map {
>   	u8 sample_rate_div;
>   	u8 lpf;
> +	u8 accel_lpf;
>   	u8 user_ctrl;
>   	u8 fifo_en;
>   	u8 gyro_config;
> @@ -188,6 +190,7 @@ struct inv_mpu6050_state {
>   #define INV_MPU6050_FIFO_THRESHOLD           500
>   
>   /* mpu6500 registers */
> +#define INV_MPU6500_REG_ACCEL_CONFIG_2      0x1D
>   #define INV_MPU6500_REG_ACCEL_OFFSET        0x77
>   
>   /* delay time in milliseconds */
> 

Re: [PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500

[Jean-Baptiste Maneyrol]

>From: Jonathan Cameron <jic23@kernel.org>
>Sent: Sunday, May 21, 2017 14:09
>To: Jean-Baptiste Maneyrol; linux-iio
>Subject: Re: [PATCH] iio: imu: inv_mpu6050: add accel lpf register setting=
 for chip >=3D MPU6500
>=A0  =20
>On 16/05/17 14:12, Jean-Baptiste Maneyrol wrote:
>> Starting from MPU6500, accelerometer dlpf is set in a separate register
>> named ACCEL_CONFIG_2.
>> Add this new register in the map and set it for the corresponding chips.
>>=20
>> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
>Perhaps a fixes tag as we presumably want this to go to stable?=A0 Can see=
 some rather
>unexpected results occurring without it.
>
>Hmm. Question to follow up is should we split the ABI to allow separate co=
ntrol.
>Ideally we probably should but technically it'd be an unnecessary userspac=
e
>interface change.=A0 The question is whether we'd actually break anything?
>
>I'd certainly prefer to see the two separate attributes to control the dif=
ferent
>low pass filters.
>
>Jonathan
>
Hello,

here is a reworked patch with a switch/case below.

There is no attribute currently to set lpf setting. It is automatically set=
 with the
correct value when setting the sampling rate (to avoid any aliases issues).
Since there is only 1 frequency for the chip (meaning a unique frequency fo=
r
both accel and gyro), there is no real need to set apart the accelerometer =
lpf value.
Better have the same behavior for both gyro and accel lpf settings, setting=
 them
both when changing the sampling rate.

That would be a good thing to send this into stable release.
If I need to do something, please tell me how to do it.

Thanks.
Jean-Baptiste


>From 8db0b6b626c7e640590df8f271de7e8e2b409f15 Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Date: Mon, 22 May 2017 14:45:21 +0200
Subject: [PATCH] iio: imu: inv_mpu6050: add accel lpf setting for chip >=3D
 MPU6500

Starting from MPU6500, accelerometer dlpf is set in a separate register
named ACCEL_CONFIG_2.
Add this new register in the map and set it for the corresponding chips.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 37 ++++++++++++++++++++++++++=
+---
 drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  3 +++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/i=
nv_mpu6050/inv_mpu_core.c
index 96dabbd..299755a 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -41,6 +41,7 @@
 static const struct inv_mpu6050_reg_map reg_set_6500 =3D {
 	.sample_rate_div	=3D INV_MPU6050_REG_SAMPLE_RATE_DIV,
 	.lpf                    =3D INV_MPU6050_REG_CONFIG,
+	.accel_lpf              =3D INV_MPU6500_REG_ACCEL_CONFIG_2,
 	.user_ctrl              =3D INV_MPU6050_REG_USER_CTRL,
 	.fifo_en                =3D INV_MPU6050_REG_FIFO_EN,
 	.gyro_config            =3D INV_MPU6050_REG_GYRO_CONFIG,
@@ -211,6 +212,37 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state=
 *st, bool power_on)
 EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
=20
 /**
+ *  inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip depen=
dent
+ *
+ *  MPU60xx/MPU9150 use only 1 register for accelerometer + gyroscope
+ *  MPU6500 and above have a dedicated register for accelerometer
+ */
+static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
+				    enum inv_mpu6050_filter_e val)
+{
+	int result;
+
+	result =3D regmap_write(st->map, st->reg->lpf, val);
+	if (result)
+		return result;
+
+	switch (st->chip_type) {
+	case INV_MPU6050:
+	case INV_MPU6000:
+	case INV_MPU9150:
+		/* old chips, nothing to do */
+		result =3D 0;
+		break;
+	default:
+		/* set accel lpf */
+		result =3D regmap_write(st->map, st->reg->accel_lpf, val);
+		break;
+	}
+
+	return result;
+}
+
+/**
  *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
  *
  *  Initial configuration:
@@ -233,8 +265,7 @@ static int inv_mpu6050_init_config(struct iio_dev *indi=
o_dev)
 	if (result)
 		return result;
=20
-	d =3D INV_MPU6050_FILTER_20HZ;
-	result =3D regmap_write(st->map, st->reg->lpf, d);
+	result =3D inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
 	if (result)
 		return result;
=20
@@ -552,7 +583,7 @@ static int inv_mpu6050_set_lpf(struct inv_mpu6050_state=
 *st, int rate)
 	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
 		i++;
 	data =3D d[i];
-	result =3D regmap_write(st->map, st->reg->lpf, data);
+	result =3D inv_mpu6050_set_lpf_regs(st, data);
 	if (result)
 		return result;
 	st->chip_config.lpf =3D data;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/in=
v_mpu6050/inv_mpu_iio.h
index ef13de7..953a0c0 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -28,6 +28,7 @@
  *  struct inv_mpu6050_reg_map - Notable registers.
  *  @sample_rate_div:	Divider applied to gyro output rate.
  *  @lpf:		Configures internal low pass filter.
+ *  @accel_lpf:		Configures accelerometer low pass filter.
  *  @user_ctrl:		Enables/resets the FIFO.
  *  @fifo_en:		Determines which data will appear in FIFO.
  *  @gyro_config:	gyro config register.
@@ -47,6 +48,7 @@
 struct inv_mpu6050_reg_map {
 	u8 sample_rate_div;
 	u8 lpf;
+	u8 accel_lpf;
 	u8 user_ctrl;
 	u8 fifo_en;
 	u8 gyro_config;
@@ -188,6 +190,7 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_FIFO_THRESHOLD           500
=20
 /* mpu6500 registers */
+#define INV_MPU6500_REG_ACCEL_CONFIG_2      0x1D
 #define INV_MPU6500_REG_ACCEL_OFFSET        0x77
=20
 /* delay time in milliseconds */
--=20
1.9.1

Re: [PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500

[Jonathan Cameron]

On Mon, 22 May 2017 12:49:50 +0000
Jean-Baptiste Maneyrol <JManeyrol@invensense.com> wrote:

> >From: Jonathan Cameron <jic23@kernel.org>
> >Sent: Sunday, May 21, 2017 14:09
> >To: Jean-Baptiste Maneyrol; linux-iio
> >Subject: Re: [PATCH] iio: imu: inv_mpu6050: add accel lpf register setting for chip >= MPU6500
> >    
> >On 16/05/17 14:12, Jean-Baptiste Maneyrol wrote:  
> >> Starting from MPU6500, accelerometer dlpf is set in a separate register
> >> named ACCEL_CONFIG_2.
> >> Add this new register in the map and set it for the corresponding chips.
> >> 
> >> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>  
> >Perhaps a fixes tag as we presumably want this to go to stable?  Can see some rather
> >unexpected results occurring without it.
> >
> >Hmm. Question to follow up is should we split the ABI to allow separate control.
> >Ideally we probably should but technically it'd be an unnecessary userspace
> >interface change.  The question is whether we'd actually break anything?
> >
> >I'd certainly prefer to see the two separate attributes to control the different
> >low pass filters.
> >
> >Jonathan
> >  
> Hello,
> 
> here is a reworked patch with a switch/case below.
> 
> There is no attribute currently to set lpf setting. It is automatically set with the
> correct value when setting the sampling rate (to avoid any aliases issues).
> Since there is only 1 frequency for the chip (meaning a unique frequency for
> both accel and gyro), there is no real need to set apart the accelerometer lpf value.
> Better have the same behavior for both gyro and accel lpf settings, setting them
> both when changing the sampling rate.
Fair enough.  Thanks for the explanation.  Please add a comment in the code
to this effect.
> 
> That would be a good thing to send this into stable release.
> If I need to do something, please tell me how to do it.
Please post new versions as a separate email titled
[PATCH v2] iio:...

It makes it easy for people to see there is a new version without searching
in the thread and also makes it trivial to apply without hand editing.

I'll sort out flagging it for stable.  If you can figure out a suitable
fixes tag that would be good, though here I guess there may be
not clear answer to that question.  I can't remember what devices were
supported when!

Jonathan
> 
> Thanks.
> Jean-Baptiste
> 
> 
> From 8db0b6b626c7e640590df8f271de7e8e2b409f15 Mon Sep 17 00:00:00 2001
> From: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
> Date: Mon, 22 May 2017 14:45:21 +0200
> Subject: [PATCH] iio: imu: inv_mpu6050: add accel lpf setting for chip >=
>  MPU6500
> 
> Starting from MPU6500, accelerometer dlpf is set in a separate register
> named ACCEL_CONFIG_2.
> Add this new register in the map and set it for the corresponding chips.
> 
> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
> ---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 37 +++++++++++++++++++++++++++---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  3 +++
>  2 files changed, 37 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 96dabbd..299755a 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -41,6 +41,7 @@
>  static const struct inv_mpu6050_reg_map reg_set_6500 = {
>  	.sample_rate_div	= INV_MPU6050_REG_SAMPLE_RATE_DIV,
>  	.lpf                    = INV_MPU6050_REG_CONFIG,
> +	.accel_lpf              = INV_MPU6500_REG_ACCEL_CONFIG_2,
>  	.user_ctrl              = INV_MPU6050_REG_USER_CTRL,
>  	.fifo_en                = INV_MPU6050_REG_FIFO_EN,
>  	.gyro_config            = INV_MPU6050_REG_GYRO_CONFIG,
> @@ -211,6 +212,37 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
>  EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
>  
>  /**
> + *  inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip dependent
> + *
> + *  MPU60xx/MPU9150 use only 1 register for accelerometer + gyroscope
> + *  MPU6500 and above have a dedicated register for accelerometer
> + */
> +static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
> +				    enum inv_mpu6050_filter_e val)
> +{
> +	int result;
> +
> +	result = regmap_write(st->map, st->reg->lpf, val);
> +	if (result)
> +		return result;
> +
> +	switch (st->chip_type) {
> +	case INV_MPU6050:
> +	case INV_MPU6000:
> +	case INV_MPU9150:
> +		/* old chips, nothing to do */
> +		result = 0;
> +		break;
> +	default:
> +		/* set accel lpf */
> +		result = regmap_write(st->map, st->reg->accel_lpf, val);
> +		break;
> +	}
> +
> +	return result;
> +}
> +
> +/**
>   *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
>   *
>   *  Initial configuration:
> @@ -233,8 +265,7 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
>  	if (result)
>  		return result;
>  
> -	d = INV_MPU6050_FILTER_20HZ;
> -	result = regmap_write(st->map, st->reg->lpf, d);
> +	result = inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
>  	if (result)
>  		return result;
>  
> @@ -552,7 +583,7 @@ static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
>  	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
>  		i++;
>  	data = d[i];
> -	result = regmap_write(st->map, st->reg->lpf, data);
> +	result = inv_mpu6050_set_lpf_regs(st, data);
>  	if (result)
>  		return result;
>  	st->chip_config.lpf = data;
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> index ef13de7..953a0c0 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> @@ -28,6 +28,7 @@
>   *  struct inv_mpu6050_reg_map - Notable registers.
>   *  @sample_rate_div:	Divider applied to gyro output rate.
>   *  @lpf:		Configures internal low pass filter.
> + *  @accel_lpf:		Configures accelerometer low pass filter.
>   *  @user_ctrl:		Enables/resets the FIFO.
>   *  @fifo_en:		Determines which data will appear in FIFO.
>   *  @gyro_config:	gyro config register.
> @@ -47,6 +48,7 @@
>  struct inv_mpu6050_reg_map {
>  	u8 sample_rate_div;
>  	u8 lpf;
> +	u8 accel_lpf;
>  	u8 user_ctrl;
>  	u8 fifo_en;
>  	u8 gyro_config;
> @@ -188,6 +190,7 @@ struct inv_mpu6050_state {
>  #define INV_MPU6050_FIFO_THRESHOLD           500
>  
>  /* mpu6500 registers */
> +#define INV_MPU6500_REG_ACCEL_CONFIG_2      0x1D
>  #define INV_MPU6500_REG_ACCEL_OFFSET        0x77
>  
>  /* delay time in milliseconds */