Re: [PATCH v4 3/4] iio: accel: adxl345: add calibration offset support

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 26 Jun 2018 00:22:42 +0900
Akinobu Mita <akinobu.mita@gmail.com> wrote:

> The ADXL345 provides the offset adjustment registers for each axis.
> This adds the iio channel information for the calibraion offsets with
> that feature.
> 
> Cc: Eva Rachel Retuya <eraretuya@gmail.com>
> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

This is fine and doesn't rely on patch 4 where there are outstanding
suggestions, so applied to the togreg branch of iio.git and pushed out
as testing for the autobuilders to play with it.

Thanks,

Jonathan

> ---
> * v4
> - Switch to use chan->address instead of scan_index
> 
>  drivers/iio/accel/adxl345_core.c | 41 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 40 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
> index 7a25840..7b29ae8 100644
> --- a/drivers/iio/accel/adxl345_core.c
> +++ b/drivers/iio/accel/adxl345_core.c
> @@ -18,6 +18,10 @@
>  #include "adxl345.h"
>  
>  #define ADXL345_REG_DEVID		0x00
> +#define ADXL345_REG_OFSX		0x1e
> +#define ADXL345_REG_OFSY		0x1f
> +#define ADXL345_REG_OFSZ		0x20
> +#define ADXL345_REG_OFS_AXIS(index)	(ADXL345_REG_OFSX + (index))
>  #define ADXL345_REG_POWER_CTL		0x2D
>  #define ADXL345_REG_DATA_FORMAT		0x31
>  #define ADXL345_REG_DATAX0		0x32
> @@ -56,7 +60,8 @@ struct adxl345_data {
>  	.modified = 1,							\
>  	.channel2 = IIO_MOD_##axis,					\
>  	.address = index,						\
> -	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
> +		BIT(IIO_CHAN_INFO_CALIBBIAS),				\
>  	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
>  }
>  
> @@ -72,6 +77,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
>  {
>  	struct adxl345_data *data = iio_priv(indio_dev);
>  	__le16 accel;
> +	unsigned int regval;
>  	int ret;
>  
>  	switch (mask) {
> @@ -94,6 +100,38 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
>  		*val2 = adxl345_uscale;
>  
>  		return IIO_VAL_INT_PLUS_MICRO;
> +	case IIO_CHAN_INFO_CALIBBIAS:
> +		ret = regmap_read(data->regmap,
> +				  ADXL345_REG_OFS_AXIS(chan->address), &regval);
> +		if (ret < 0)
> +			return ret;
> +		/*
> +		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
> +		 * factor
> +		 */
> +		*val = sign_extend32(regval, 7) * 4;
> +
> +		return IIO_VAL_INT;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int adxl345_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val, int val2, long mask)
> +{
> +	struct adxl345_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_CALIBBIAS:
> +		/*
> +		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
> +		 * factor
> +		 */
> +		return regmap_write(data->regmap,
> +				    ADXL345_REG_OFS_AXIS(chan->address),
> +				    val / 4);
>  	}
>  
>  	return -EINVAL;
> @@ -101,6 +139,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
>  
>  static const struct iio_info adxl345_info = {
>  	.read_raw	= adxl345_read_raw,
> +	.write_raw	= adxl345_write_raw,
>  };
>  
>  int adxl345_core_probe(struct device *dev, struct regmap *regmap,