Extend the inkern api with functions for reading and writing ext_info
of iio channels.
Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
---
drivers/iio/inkern.c | 60 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 37 +++++++++++++++++++++++++++
2 files changed, 97 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 7a13535dc3e9..8292ad4435ea 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -869,3 +869,63 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
return ret;
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);
+
+unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+ unsigned int i = 0;
+
+ if (!chan->channel->ext_info)
+ return i;
+
+ for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
+ ++i;
+
+ return i;
+}
+EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
+
+static const struct iio_chan_spec_ext_info *iio_lookup_ext_info(
+ const struct iio_channel *chan,
+ const char *attr)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+
+ if (!chan->channel->ext_info)
+ return NULL;
+
+ for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
+ if (!strcmp(attr, ext_info->name))
+ return ext_info;
+ }
+
+ return NULL;
+}
+
+ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+
+ ext_info = iio_lookup_ext_info(chan, attr);
+ if (!ext_info)
+ return -EINVAL;
+
+ return ext_info->read(chan->indio_dev, ext_info->private,
+ chan->channel, buf);
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
+
+ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
+ const char *buf, size_t len)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+
+ ext_info = iio_lookup_ext_info(chan, attr);
+ if (!ext_info)
+ return -EINVAL;
+
+ return ext_info->write(chan->indio_dev, ext_info->private,
+ chan->channel, buf, len);
+}
+EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 47eeec3218b5..5e347a9805fd 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -312,4 +312,41 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val,
int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
int *processed, unsigned int scale);
+/**
+ * iio_get_channel_ext_info_count() - get number of ext_info attributes
+ * connected to the channel.
+ * @chan: The channel being queried
+ *
+ * Returns the number of ext_info attributes
+ */
+unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan);
+
+/**
+ * iio_read_channel_ext_info() - read ext_info attribute from a given channel
+ * @chan: The channel being queried.
+ * @attr: The ext_info attribute to read.
+ * @buf: Where to store the attribute value. Assumed to hold
+ * at least PAGE_SIZE bytes.
+ *
+ * Returns the number of bytes written to buf (perhaps w/o zero termination;
+ * it need not even be a string), or an error code.
+ */
+ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf);
+
+/**
+ * iio_write_channel_ext_info() - write ext_info attribute from a given channel
+ * @chan: The channel being queried.
+ * @attr: The ext_info attribute to read.
+ * @buf: The new attribute value. Strings needs to be zero-
+ * terminated, but the terminator should not be included
+ * in the below len.
+ * @len: The size of the new attribute value.
+ *
+ * Returns the number of accepted bytes, which should be the same as len.
+ * An error code can also be returned.
+ */
+ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
+ const char *buf, size_t len);
+
#endif
--
2.1.4
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