Re: [PATCH 2/2] iio: Handle enumerated properties with gaps

From: Jonathan Cameron
Date: Mon Apr 22 2019 - 06:38:41 EST


On Mon, 22 Apr 2019 11:32:57 +0300
Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:

> From: Lars-Peter Clausen <lars@xxxxxxxxxx>
>
> Some enums might have gaps or reserved values in the middle of their value
> range. E.g. consider a 2-bit enum where the values 0, 1 and 3 have a
> meaning, but 2 is a reserved value and can not be used.
>
> Add support for such enums to the IIO enum helper functions. A reserved
> values is marked by setting its entry in the items array to NULL rather
> than the normal descriptive string value.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
Looks good, subject to the whole gaps parameter discussion on patch
1.

Thanks,

Jonathan

> ---
> drivers/iio/industrialio-core.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index f2ebca65f964..c141a29bf446 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -447,8 +447,11 @@ ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
> if (!e->num_items)
> return 0;
>
> - for (i = 0; i < e->num_items; ++i)
> + for (i = 0; i < e->num_items; ++i) {
> + if (!e->items[i])
> + continue;
> len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
> + }
>
> /* replace last space with a newline */
> buf[len - 1] = '\n';
> @@ -469,7 +472,7 @@ ssize_t iio_enum_read(struct iio_dev *indio_dev,
> i = e->get(indio_dev, chan);
> if (i < 0)
> return i;
> - else if (i >= e->num_items)
> + else if (i >= e->num_items || !e->items[i])
> return -EINVAL;
>
> return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
> @@ -486,7 +489,8 @@ ssize_t iio_enum_write(struct iio_dev *indio_dev,
> if (!e->set)
> return -EINVAL;
>
> - ret = __sysfs_match_string(e->items, e->num_items, buf);
> + ret = __sysfs_match_string_with_gaps(e->items, e->num_items,
> + buf, true);
> if (ret < 0)
> return ret;
>