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

[H. Nikolaus Schaller]

> Am 20.02.2019 um 17:14 schrieb Jonathan Cameron <jic23@xxxxxxxxxx>:
> 
> On Wed, 20 Feb 2019 15:00:50 +0100
> "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> This will clash with Andy's current patch, but I'll fix that up if
> needed. Otherwise, one trivial suggestion inline.

Ok, thanks!

> 
> 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!

Yes, Andy already suggested that. I just happend to pick one of the only two bad examples
from all iio drivers as template...

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
drivers/iio/magnetometer/ak8975.c

> 
>> +}
>> +
>> +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;
> 

BR and thanks,
Nikolaus