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

Alexandru Ardelean
2019-04-22T08:33:10Z

From: Lars-Peter Clausen <lars@metafoo.de>

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@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
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;

--
2.17.1