firmware: arm_scmi: Add name and protocol id attributes

Add the name and the protocol id attributes to the SCMI devices on the
bus so that they are exposed to the user-space via the sysfs.

Message-Id: <20250131141822.514342-2-sudeep.holla@arm.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 8acf33ccfd2174cde323aba6c2fabf344731b607..862dd34eca624fc25673bd7c1c316871d2275b42 100644 (file)
--- 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);
 
@@ -276,11 +278,47 @@ 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 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,
+       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);