github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-06 21:58:01 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

iio: core: add hierarchical channel relationships

Browse Source 
Add parent-child relationship between iio channels by creating a parent
pointer field in iio_chan_spec struct and exposing a sysfs attribute that
returns the parent channel prefix.

Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
This commit is contained in:
Rodrigo Alencar 2026-07-29 09:25:35 +01:00 committed by Jonathan Cameron
parent b9f9044be7
commit ef7fcf86cc
2 changed files with 43 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/iio/industrialio-core.c
View File

@ -859,6 +859,20 @@ static ssize_t iio_read_channel_label(struct device *dev,
to_iio_dev_attr(attr)->c, buf);
}
static ssize_t iio_read_channel_parent(struct device *dev,
struct device_attribute *attr,
char *buf)
{
const struct iio_chan_spec *chan = to_iio_dev_attr(attr)->c->parent;
ssize_t len;
len = __iio_chan_prefix_emit(dev, chan, IIO_SEPARATE, buf, PAGE_SIZE - 1);
if (len < 0)
return len;
return len + sysfs_emit_at(buf, len, "\n");
}
static ssize_t iio_read_channel_info(struct device *dev,
struct device_attribute *attr,
char *buf)
@ -1273,6 +1287,25 @@ static int iio_device_add_channel_label(struct iio_dev *indio_dev,
return 1;
}
static int iio_device_add_channel_parent_attr(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
int ret;
if (!chan->parent)
return 0;
ret = __iio_add_chan_devattr("parent", chan,
&iio_read_channel_parent, NULL,
0, IIO_SEPARATE, &indio_dev->dev, NULL,
&iio_dev_opaque->channel_attr_list);
if (ret < 0)
return ret;
return 1;
}
static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
enum iio_shared_by shared_by,
@ -1411,6 +1444,11 @@ static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
return ret;
attrcount += ret;
ret = iio_device_add_channel_parent_attr(indio_dev, chan);
if (ret < 0)
return ret;
attrcount += ret;
if (chan->ext_info) {
unsigned int i = 0;

5
include/linux/iio/iio.h
View File

@ -264,6 +264,10 @@ struct iio_scan_type {
* @ext_info: Array of extended info attributes for this channel.
* The array is NULL terminated, the last element should
* have its name field set to NULL.
* @parent: Optional pointer to the parent channel spec for
* hierarchical channel relationships. When set, a read-only
* "parent" sysfs attribute is created containing the
* parent channel's sysfs name prefix (e.g. "in_voltage0").
* @extend_name: Allows labeling of channel attributes with an
* informative name. Note this has no effect codes etc,
* unlike modifiers.
@ -309,6 +313,7 @@ struct iio_chan_spec {
const struct iio_event_spec *event_spec;
unsigned int num_event_specs;
const struct iio_chan_spec_ext_info *ext_info;
const struct iio_chan_spec *parent;
const char *extend_name;
const char *datasheet_name;
unsigned int modified:1;