From: Dave Jiang <dave.jiang@xxxxxxxxx>
Enable sysfs attribute emission of the number of features supported by the
driver/device. This is useful for userspace to determine the number of features
to query for.
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
drivers/cxl/features.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/cxl/features.c b/drivers/cxl/features.c
index 2cdf5ed0a771..2f0fb072921e 100644
--- a/drivers/cxl/features.c
+++ b/drivers/cxl/features.c
@@ -173,11 +173,38 @@ static void cxl_features_remove(struct device *dev)
kfree(cfs);
}
+static ssize_t features_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct cxl_features_state *cfs = dev_get_drvdata(dev);
+
+ if (!cfs)
+ return -ENOENT;
+
+ return sysfs_emit(buf, "%d\n", cfs->num_features);
+}
+
+static DEVICE_ATTR_RO(features);
+
+static struct attribute *cxl_features_attrs[] = {
+ &dev_attr_features.attr,
+ NULL
+};
+
+static struct attribute_group cxl_features_group = {
+ .attrs = cxl_features_attrs,
+};
+
+__ATTRIBUTE_GROUPS(cxl_features);
+
static struct cxl_driver cxl_features_driver = {
.name = "cxl_features",
.probe = cxl_features_probe,
.remove = cxl_features_remove,
.id = CXL_DEVICE_FEATURES,
+ .drv = {
+ .dev_groups = cxl_features_groups,
+ },
};
module_cxl_driver(cxl_features_driver);
--
2.43.0
