It's very convenient to see what properties and their values
are currently being assigned in the registered software nodes.

Show properties and their values in sysfs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/base/swnode.c | 137 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 132 insertions(+), 5 deletions(-)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 19aa44bc2628..d7fe1a887d2d 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c

@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include <linux/sysfs.h>
 
 struct swnode {
 	int id;

@@ -17,6 +18,10 @@ struct swnode {
 	struct fwnode_handle fwnode;
 	const struct software_node *node;
 
+	/* properties in sysfs */
+	struct kobj_attribute *property_attrs;
+	struct attribute_group property_group;
+
 	/* hierarchy */
 	struct ida child_ids;
 	struct list_head entry;

@@ -25,6 +30,7 @@ struct swnode {
 
 	unsigned int allocated:1;
 	unsigned int managed:1;
+	unsigned int properties:1;
 };
 
 static DEFINE_IDA(swnode_root_ids);

@@ -299,6 +305,18 @@ static int property_entry_copy_data(struct property_entry *dst,
 	return 0;
 }
 
+static int property_entries_count(const struct property_entry *properties)
+{
+	int n = 0;
+
+	if (properties) {
+		while (properties[n].name)
+			n++;
+	}
+
+	return n;
+}
+
 /**
  * property_entries_dup - duplicate array of properties
  * @properties: array of properties to copy

@@ -310,15 +328,13 @@ struct property_entry *
 property_entries_dup(const struct property_entry *properties)
 {
 	struct property_entry *p;
-	int i, n = 0;
+	int i, n;
 	int ret;
 
-	if (!properties)
+	n = property_entries_count(properties);
+	if (n == 0)
 		return NULL;
 
-	while (properties[n].name)
-		n++;
-
 	p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return ERR_PTR(-ENOMEM);

@@ -746,6 +762,108 @@ static void software_node_free(const struct software_node *node)
 	kfree(node);
 }
 
+static ssize_t
+swnode_property_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct swnode *swnode = kobj_to_swnode(kobj);
+	const struct property_entry *prop;
+	const void *pointer;
+	ssize_t len = 0;
+	int i;
+
+	prop = property_entry_get(swnode->node->properties, attr->attr.name);
+	if (!prop)
+		return -EINVAL;
+
+	/* We can't fail here, because it means boolean property */
+	pointer = property_get_pointer(prop);
+	if (!pointer)
+		return sysfs_emit(buf, "\n");
+
+	switch (prop->type) {
+	case DEV_PROP_U8:
+		for (i = 0; i < prop->length / sizeof(u8); i++)
+			len += sysfs_emit_at(buf, len, "%u,", ((u8 *)pointer)[i]);