firmware: arm_scmi: Add optional transport_init/exit support
Some SCMI transport could need to perform some transport specific setup
before they can be used by the SCMI core transport layer: typically this
early setup consists in registering with some other kernel subsystem.
Add the optional capability for a transport to provide a couple of init
and exit functions that are assured to be called early during the SCMI
core initialization phase, well before the SCMI core probing step.
[ Peter: Adapted RFC patch by Cristian for submission to upstream. ]
Link: https://lore.kernel.org/r/20210803131024.40280-4-cristian.marussi@arm.com
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Fixed scmi_transports_exit point of invocation ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index bd7f81b..374bf97 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1581,10 +1581,65 @@ static struct platform_driver scmi_driver = {
.remove = scmi_remove,
};
+/**
+ * __scmi_transports_setup - Common helper to call transport-specific
+ * .init/.exit code if provided.
+ *
+ * @init: A flag to distinguish between init and exit.
+ *
+ * Note that, if provided, we invoke .init/.exit functions for all the
+ * transports currently compiled in.
+ *
+ * Return: 0 on Success.
+ */
+static inline int __scmi_transports_setup(bool init)
+{
+ int ret = 0;
+ const struct of_device_id *trans;
+
+ for (trans = scmi_of_match; trans->data; trans++) {
+ const struct scmi_desc *tdesc = trans->data;
+
+ if ((init && !tdesc->transport_init) ||
+ (!init && !tdesc->transport_exit))
+ continue;
+
+ if (init)
+ ret = tdesc->transport_init();
+ else
+ tdesc->transport_exit();
+
+ if (ret) {
+ pr_err("SCMI transport %s FAILED initialization!\n",
+ trans->compatible);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int __init scmi_transports_init(void)
+{
+ return __scmi_transports_setup(true);
+}
+
+static void __exit scmi_transports_exit(void)
+{
+ __scmi_transports_setup(false);
+}
+
static int __init scmi_driver_init(void)
{
+ int ret;
+
scmi_bus_init();
+ /* Initialize any compiled-in transport which provided an init/exit */
+ ret = scmi_transports_init();
+ if (ret)
+ return ret;
+
scmi_base_register();
scmi_clock_register();
@@ -1613,6 +1668,8 @@ static void __exit scmi_driver_exit(void)
scmi_bus_exit();
+ scmi_transports_exit();
+
platform_driver_unregister(&scmi_driver);
}
module_exit(scmi_driver_exit);
