1 files changed, 56 insertions, 13 deletions

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index a3386bf36de5..7af01664ce7e 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -17,6 +17,8 @@
 
 #include "common.h"
 
+#define SCMI_UEVENT_MODALIAS_FMT	"%s:%02x:%s"
+
 BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh);
 EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
 
@@ -42,7 +44,7 @@ static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
  * This helper let an SCMI driver request specific devices identified by the
  * @id_table to be created for each active SCMI instance.
  *
- * The requested device name MUST NOT be already existent for any protocol;
+ * The requested device name MUST NOT be already existent for this protocol;
  * at first the freshly requested @id_table is annotated in the IDR table
  * @scmi_requested_devices and then the requested device is advertised to any
  * registered party via the @scmi_requested_devices_nh notification chain.
@@ -52,7 +54,6 @@ static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
 static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 {
 	int ret = 0;
-	unsigned int id = 0;
 	struct list_head *head, *phead = NULL;
 	struct scmi_requested_dev *rdev;
 
@@ -67,19 +68,13 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	}
 
 	/*
-	 * Search for the matching protocol rdev list and then search
-	 * of any existent equally named device...fails if any duplicate found.
+	 * Find the matching protocol rdev list and then search of any
+	 * existent equally named device...fails if any duplicate found.
 	 */
 	mutex_lock(&scmi_requested_devices_mtx);
-	idr_for_each_entry(&scmi_requested_devices, head, id) {
-		if (!phead) {
-			/* A list found registered in the IDR is never empty */
-			rdev = list_first_entry(head, struct scmi_requested_dev,
-						node);
-			if (rdev->id_table->protocol_id ==
-			    id_table->protocol_id)
-				phead = head;
-		}
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		head = phead;
 		list_for_each_entry(rdev, head, node) {
 			if (!strcmp(rdev->id_table->name, id_table->name)) {
 				pr_err("Ignoring duplicate request [%d] %s\n",
@@ -283,11 +278,59 @@ static void scmi_dev_remove(struct device *dev)
 		scmi_drv->remove(scmi_dev);
 }
 
+static int scmi_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return add_uevent_var(env, "MODALIAS=" SCMI_UEVENT_MODALIAS_FMT,
+			      dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			      scmi_dev->name);
+}
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sysfs_emit(buf, SCMI_UEVENT_MODALIAS_FMT,
+			  dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			  scmi_dev->name);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t protocol_id_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "0x%02x\n", scmi_dev->protocol_id);
+}
+static DEVICE_ATTR_RO(protocol_id);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "%s\n", scmi_dev->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *scmi_device_attributes_attrs[] = {
+	&dev_attr_protocol_id.attr,
+	&dev_attr_name.attr,
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(scmi_device_attributes);
+
 const struct bus_type scmi_bus_type = {
 	.name =	"scmi_protocol",
 	.match = scmi_dev_match,
 	.probe = scmi_dev_probe,
 	.remove = scmi_dev_remove,
+	.uevent	= scmi_device_uevent,
+	.dev_groups = scmi_device_attributes_groups,
 };
 EXPORT_SYMBOL_GPL(scmi_bus_type);