Commit a53f9458 authored by Carlos Song's avatar Carlos Song Committed by Jonathan Cameron
Browse files

iio: imu: fxos8700: fix IMU data bits returned to user space 



ACCEL output data registers contain the X-axis, Y-axis, and Z-axis
14-bit left-justified sample data and MAGN output data registers
contain the X-axis, Y-axis, and Z-axis 16-bit sample data. The ACCEL
raw register output data should be divided by 4 before sent to
userspace.

Apply a 2 bits signed right shift to the raw data from ACCEL output
data register but keep that from MAGN sensor as the origin.

Fixes: 84e5ddd5 ("iio: imu: Add support for the FXOS8700 IMU")
Signed-off-by: default avatarCarlos Song <carlos.song@nxp.com>
Link: https://lore.kernel.org/r/20221208071911.2405922-5-carlos.song@nxp.com


Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 37a94d86

drivers/iio/imu/fxos8700_core.c

+27 −1
Original line number Diff line number Diff line
@@ -394,6 +394,7 @@ static int fxos8700_get_data(struct fxos8700_data *data, int chan_type, 
			     int axis, int *val)

{

	u8 base, reg;

	s16 tmp;

	int ret;



	/*
@@ -421,8 +422,33 @@ static int fxos8700_get_data(struct fxos8700_data *data, int chan_type, 
	/* Convert axis to buffer index */

	reg = axis - IIO_MOD_X;



	/*

	 * Convert to native endianness. The accel data and magn data

	 * are signed, so a forced type conversion is needed.

	 */

	tmp = be16_to_cpu(data->buf[reg]);



	/*

	 * ACCEL output data registers contain the X-axis, Y-axis, and Z-axis

	 * 14-bit left-justified sample data and MAGN output data registers

	 * contain the X-axis, Y-axis, and Z-axis 16-bit sample data. Apply

	 * a signed 2 bits right shift to the readback raw data from ACCEL

	 * output data register and keep that from MAGN sensor as the origin.

	 * Value should be extended to 32 bit.

	 */

	switch (chan_type) {

	case IIO_ACCEL:

		tmp = tmp >> 2;

		break;

	case IIO_MAGN:

		/* Nothing to do */

		break;

	default:

		return -EINVAL;

	}



	/* Convert to native endianness */

	*val = sign_extend32(be16_to_cpu(data->buf[reg]), 15);

	*val = sign_extend32(tmp, 15);



	return 0;

}