Re: [PATCH 3/9] iio: accel: bmc150: add mount matrix support

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 20 Feb 2019 15:00:50 +0100
"H. Nikolaus Schaller" <hns@goldelico.com> wrote:

> This patch allows to read a mount-matrix device tree
> property and report to user-space or in-kernel iio
> clients.
> 
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
This will clash with Andy's current patch, but I'll fix that up if
needed. Otherwise, one trivial suggestion inline.

Jonathan

> ---
>  drivers/iio/accel/bmc150-accel-core.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c
> index 383c802eb5b8..9178846cfddc 100644
> --- a/drivers/iio/accel/bmc150-accel-core.c
> +++ b/drivers/iio/accel/bmc150-accel-core.c
> @@ -204,6 +204,7 @@ struct bmc150_accel_data {
>  	int ev_enable_state;
>  	int64_t timestamp, old_timestamp; /* Only used in hw fifo mode. */
>  	const struct bmc150_accel_chip_info *chip_info;
> +	struct iio_mount_matrix orientation;
>  };
>  
>  static const struct {
> @@ -796,6 +797,18 @@ static ssize_t bmc150_accel_get_fifo_state(struct device *dev,
>  	return sprintf(buf, "%d\n", state);
>  }
>  
> +static const struct iio_mount_matrix *
> +bmc150_accel_get_mount_matrix(const struct iio_dev *indio_dev,
> +				const struct iio_chan_spec *chan)
> +{
> +	return &((struct bmc150_accel_data *)iio_priv(indio_dev))->orientation;

I would use a local variable as that casting is less than simple to parse
to my eyes anyway!

> +}
> +
> +static const struct iio_chan_spec_ext_info bmc150_accel_ext_info[] = {
> +	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bmc150_accel_get_mount_matrix),
> +	{ },
> +};
> +
>  static IIO_CONST_ATTR(hwfifo_watermark_min, "1");
>  static IIO_CONST_ATTR(hwfifo_watermark_max,
>  		      __stringify(BMC150_ACCEL_FIFO_LENGTH));
> @@ -978,6 +991,7 @@ static const struct iio_event_spec bmc150_accel_event = {
>  		.shift = 16 - (bits),					\
>  		.endianness = IIO_LE,					\
>  	},								\
> +	.ext_info = bmc150_accel_ext_info,				\
>  	.event_spec = &bmc150_accel_event,				\
>  	.num_event_specs = 1						\
>  }
> @@ -1555,6 +1569,11 @@ int bmc150_accel_core_probe(struct device *dev, struct regmap *regmap, int irq,
>  
>  	data->regmap = regmap;
>  
> +	ret = of_iio_read_mount_matrix(dev, "mount-matrix",
> +				       &data->orientation);
> +	if (ret)
> +		return ret;
> +
>  	ret = bmc150_accel_chip_init(data);
>  	if (ret < 0)
>  		return ret;