Re: [PATCH 1/2] iio:accel:bma180: Use modifier instead of index in channel specification

[Jonathan Cameron <jic23@kernel.org>]

On 10/01/14 21:37, Peter Meerwald wrote:
> should use channel modifiers (X/Y/Z), not channel indices
> timestamp channel has scan index 3, not 4
>
Aag.  Whilst a correct fix, this is going to result in a userspace ABI
change.  Driver has been in since 3.12.  We may need to maintain
both ABI's for now and then deprecate it at some point.  Easiest way to do this
will be to have two sets of iio_chan_specs pointing at the same underlying
real channels.

Anyone have a strong opinion about this?

Good spot by the way!

> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
> Cc: Kravchenko Oleksandr <x0199363@ti.com>
> ---
>   drivers/iio/accel/bma180.c | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> index 3bec922..bfec313 100644
> --- a/drivers/iio/accel/bma180.c
> +++ b/drivers/iio/accel/bma180.c
> @@ -447,14 +447,14 @@ static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
>   	{ },
>   };
>
> -#define BMA180_CHANNEL(_index) {					\
> +#define BMA180_CHANNEL(_axis) {					\
>   	.type = IIO_ACCEL,						\
> -	.indexed = 1,							\
> -	.channel = (_index),						\
> +	.modified = 1,							\
> +	.channel2 = IIO_MOD_##_axis,					\
>   	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
>   		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
>   	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
> -	.scan_index = (_index),						\
> +	.scan_index = AXIS_##_axis,					\
>   	.scan_type = {							\
>   		.sign = 's',						\
>   		.realbits = 14,						\
> @@ -465,10 +465,10 @@ static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
>   }
>
>   static const struct iio_chan_spec bma180_channels[] = {
> -	BMA180_CHANNEL(AXIS_X),
> -	BMA180_CHANNEL(AXIS_Y),
> -	BMA180_CHANNEL(AXIS_Z),
> -	IIO_CHAN_SOFT_TIMESTAMP(4),
> +	BMA180_CHANNEL(X),
> +	BMA180_CHANNEL(Y),
> +	BMA180_CHANNEL(Z),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
>   };
>
>   static irqreturn_t bma180_trigger_handler(int irq, void *p)
>