iio: Add iio_read_channel_label to inkern API

It can be convenient for other in-kernel drivers to reuse IIO channel
labels. Export the iio_read_channel_label function to allow this. The
signature is different depending on where we are calling it from, so
the meat is moved to do_iio_read_channel_label.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20240624174601.1527244-2-sean.anderson@linux.dev
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Sean Anderson 2024-06-24 13:46:00 -04:00 committed by Jonathan Cameron
parent 9641972917
commit 0214b27fc9
4 changed files with 35 additions and 10 deletions

View File

@ -34,6 +34,10 @@ void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
struct iio_ioctl_handler *h);
void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h);
ssize_t do_iio_read_channel_label(struct iio_dev *indio_dev,
const struct iio_chan_spec *c,
char *buf);
int __iio_add_chan_devattr(const char *postfix,
struct iio_chan_spec const *chan,
ssize_t (*func)(struct device *dev,

View File

@ -727,20 +727,25 @@ ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
}
EXPORT_SYMBOL_GPL(iio_format_value);
ssize_t do_iio_read_channel_label(struct iio_dev *indio_dev,
const struct iio_chan_spec *c,
char *buf)
{
if (indio_dev->info->read_label)
return indio_dev->info->read_label(indio_dev, c, buf);
if (c->extend_name)
return sysfs_emit(buf, "%s\n", c->extend_name);
return -EINVAL;
}
static ssize_t iio_read_channel_label(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
if (indio_dev->info->read_label)
return indio_dev->info->read_label(indio_dev, this_attr->c, buf);
if (this_attr->c->extend_name)
return sysfs_emit(buf, "%s\n", this_attr->c->extend_name);
return -EINVAL;
return do_iio_read_channel_label(dev_to_iio_dev(dev),
to_iio_dev_attr(attr)->c, buf);
}
static ssize_t iio_read_channel_info(struct device *dev,

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@ -1010,3 +1010,9 @@ ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
chan->channel, buf, len);
}
EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf)
{
return do_iio_read_channel_label(chan->indio_dev, chan->channel, buf);
}
EXPORT_SYMBOL_GPL(iio_read_channel_label);

View File

@ -441,4 +441,14 @@ ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
const char *buf, size_t len);
/**
* iio_read_channel_label() - read label for a given channel
* @chan: The channel being queried.
* @buf: Where to store the attribute value. Assumed to hold
* at least PAGE_SIZE bytes.
*
* Returns the number of bytes written to buf, or an error code.
*/
ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf);
#endif