[PATCH v4 15/17] staging: iio: resolver: ad2s1210: add label attribute support

From: David Lechner
Date: Thu Oct 05 2023 - 20:52:10 EST


The ad2s1210 resolver driver has quite a few channels, mostly for
internal signals for event support. This makes it difficult to know
which channel is which. This patch adds a label attribute to the
channels to make it easier to identify them.

Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
---

v4 changes:
* Adjusted for channel rearrangement in previous patches.

v3 changes: This is a new patch in v3

drivers/staging/iio/resolver/ad2s1210.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
index 51490fea1647..59c8eed26701 100644
--- a/drivers/staging/iio/resolver/ad2s1210.c
+++ b/drivers/staging/iio/resolver/ad2s1210.c
@@ -1158,6 +1158,34 @@ static int ad2s1210_initial(struct ad2s1210_state *st)
return ret;
}

+static int ad2s1210_read_label(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ char *label)
+{
+ if (chan->type == IIO_ANGL) {
+ if (chan->channel == 0)
+ return sprintf(label, "position\n");
+ if (chan->channel == 1)
+ return sprintf(label, "tracking error\n");
+ }
+ if (chan->type == IIO_ANGL_VEL)
+ return sprintf(label, "velocity\n");
+ if (chan->type == IIO_PHASE)
+ return sprintf(label, "synthetic reference\n");
+ if (chan->type == IIO_ALTVOLTAGE) {
+ if (chan->output)
+ return sprintf(label, "excitation\n");
+ if (chan->channel == 0)
+ return sprintf(label, "monitor signal\n");
+ if (chan->channel == 1)
+ return sprintf(label, "cosine\n");
+ if (chan->channel == 2)
+ return sprintf(label, "sine\n");
+ }
+
+ return -EINVAL;
+}
+
static int ad2s1210_read_event_value(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
@@ -1338,6 +1366,7 @@ static const struct iio_info ad2s1210_info = {
.read_raw = ad2s1210_read_raw,
.read_avail = ad2s1210_read_avail,
.write_raw = ad2s1210_write_raw,
+ .read_label = ad2s1210_read_label,
.attrs = &ad2s1210_attribute_group,
.read_event_value = ad2s1210_read_event_value,
.write_event_value = ad2s1210_write_event_value,

--
2.42.0