Add IIO_STATIC_CONST_DEVICE_ATTR macro for creating an read-only
iio_dev_attr which returns constant value. This macro is intended to be
used when replacing the IIO_CONST_ATTR - attributes for triggered
buffers because the triggered buffer attributes must be of type
iio_dev_attr.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 include/linux/iio/sysfs.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/iio/sysfs.h b/include/linux/iio/sysfs.h
index e51fba66de4b..de5bb125815c 100644
--- a/include/linux/iio/sysfs.h
+++ b/include/linux/iio/sysfs.h
@@ -97,6 +97,17 @@ struct iio_const_attr {
 	= { .string = _string,						\
 	    .dev_attr = __ATTR(_name, S_IRUGO, iio_read_const_attr, NULL)}
 
+#define IIO_STATIC_CONST_DEVICE_ATTR(_name, _string)				\
+	static ssize_t iio_const_dev_attr_show_##_name(			\
+					struct device *dev,		\
+					struct device_attribute *attr,	\
+					char *buf)			\
+	{								\
+		return sysfs_emit(buf, "%s\n", _string);		\
+	}								\
+	static IIO_DEVICE_ATTR(_name, 0444,				\
+			       iio_const_dev_attr_show_##_name, NULL, 0)
+
 /* Generic attributes of onetype or another */
 
 /**
-- 
2.37.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]