[PATCH] firmware: arm_scmi: Add multiple protocols registration support

[Cristian Marussi]

Add the capability for one SCMI driver to register with the core SCMI stack
to use multiple SCMI protocols: in such a case the SCMI driver probe
function will end up being called once for each registered protocol which
have been also found as implemented on the platform.

This is especially useful in testing scenarios.

Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
 drivers/firmware/arm_scmi/bus.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index c15928b8c5cc..1f9735dbebec 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -141,6 +141,17 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	return ret;
 }
 
+static int scmi_protocol_table_register(const struct scmi_device_id *id_table)
+{
+	int ret = 0;
+	const struct scmi_device_id *entry;
+
+	for (entry = id_table; entry->name && ret == 0; entry++)
+		ret = scmi_protocol_device_request(entry);
+
+	return ret;
+}
+
 /**
  * scmi_protocol_device_unrequest  - Helper to unrequest a device
  *
@@ -186,6 +197,15 @@ static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table
 	mutex_unlock(&scmi_requested_devices_mtx);
 }
 
+static void
+scmi_protocol_table_unregister(const struct scmi_device_id *id_table)
+{
+	const struct scmi_device_id *entry;
+
+	for (entry = id_table; entry->name; entry++)
+		scmi_protocol_device_unrequest(entry);
+}
+
 static const struct scmi_device_id *
 scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
 {
@@ -279,7 +299,7 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 	if (!driver->probe)
 		return -EINVAL;
 
-	retval = scmi_protocol_device_request(driver->id_table);
+	retval = scmi_protocol_table_register(driver->id_table);
 	if (retval)
 		return retval;
 
@@ -299,7 +319,7 @@ EXPORT_SYMBOL_GPL(scmi_driver_register);
 void scmi_driver_unregister(struct scmi_driver *driver)
 {
 	driver_unregister(&driver->driver);
-	scmi_protocol_device_unrequest(driver->id_table);
+	scmi_protocol_table_unregister(driver->id_table);
 }
 EXPORT_SYMBOL_GPL(scmi_driver_unregister);
 
-- 
2.43.0