Merge tag 'scmi-updates-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into soc/drivers

Arm SCMI updates for v6.9

Quite a few changes to extend support to SCMI v3.2 specification,
to enhance notification handling and other miscellaneous updates.

1. Enhancements to notification handling

   Until now, trying to register a notifier for an unsuppported
   notification returned an error genrating unneeded message exchanges
   with the SCMI platform. This can be avoided by looking up in advance
   the specific protocol and resources available.

   With these changes SCMI driver user will fail to register a notifier
   if the related command or resource is not supported (like before)
   without the need of exchanging any message.

   Perf notifications are also extended to provide the pre-calculated
   frequencies corresponding to the level or index carried by the

2. More SCMI v3.2 related updates

   One of the main addition includes a centralized support to the SCMI
   core to handle v3.2 optional protocol version negotiation, so that
   at protocol initialization time, if the platform advertised version
   is newer than supported by the kernel and protocol version negotiation
   is supported, the SCMI core will attempt to negotiate an older protocol
   version.

   It also includes the clock get permissions which indicates if any of
   the clock operations are forbidden by the platform for the OSPM agent.
   It can be used in the clock driver to avoid unnecessary message
   exchanges between the kernel and the platform which will always end
   up with the failure. It also includes other missing bits of clock
   v3.2 protocol so that the supported protocol version can be bumped
   to 0x30000 (v3.2).

3. Miscellaneous updates

   This includes addition of warning if the domain frequency multiplier
   is 0 or rounded off to indicate the actual frequencies are either
   wrong ot rounded off, hardening of clock domain info lookups, addition
   of multiple protocols registration support within a SCMI driver,
   update to SCMI entry in MAINTAINERS to include HWMON driver and
   constifying the scmi_bus_type structure.

   This also includes couple for fixes to minor issues: double free in
   SMC transport cleanup path and struct kernel-doc warnings in optee
   transport.

* tag 'scmi-updates-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: (29 commits)
  MAINTAINERS: Update SCMI entry with HWMON driver
  firmware: arm_scmi: Update the supported clock protocol version
  firmware: arm_scmi: Add standard clock OEM definitions
  firmware: arm_scmi: Add clock check for extended config support
  firmware: arm_scmi: Add support for v3.2 NEGOTIATE_PROTOCOL_VERSION
  firmware: arm_scmi: Fix struct kernel-doc warnings in optee transport
  firmware: arm_scmi: Report frequencies in the perf notifications
  firmware: arm_scmi: Use opps_by_lvl to store opps
  firmware: arm_scmi: Implement is_notify_supported callback in powercap protocol
  firmware: arm_scmi: Implement is_notify_supported callback in reset protocol
  firmware: arm_scmi: Implement is_notify_supported callback in sensor protocol
  firmware: arm_scmi: Implement is_notify_supported callback in clock protocol
  firmware: arm_scmi: Implement is_notify_supported callback in system power protocol
  firmware: arm_scmi: Implement is_notify_supported callback in power protocol
  firmware: arm_scmi: Implement is_notify_supported callback in perf protocol
  firmware: arm_scmi: Add a common helper to check if a message is supported
  firmware: arm_scmi: Check for notification support
  firmware: arm_scmi: Make scmi_bus_type const
  firmware: arm_scmi: Fix double free in SMC transport cleanup path
  firmware: arm_scmi: Implement clock get permissions
  ...

Link: https://lore.kernel.org/r/20240223033435.118028-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: arndb

MAINTAINERS

@@ -21319,6 +21319,7 @@ F:	drivers/clk/clk-sc[mp]i.c
 F:	drivers/cpufreq/sc[mp]i-cpufreq.c
 F:	drivers/firmware/arm_scmi/
 F:	drivers/firmware/arm_scpi.c
+F:	drivers/hwmon/scmi-hwmon.c
 F:	drivers/pmdomain/arm/
 F:	drivers/powercap/arm_scmi_powercap.c
 F:	drivers/regulator/scmi-regulator.c

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)
 {
@@ -263,7 +283,7 @@ static void scmi_dev_remove(struct device *dev)
 		scmi_drv->remove(scmi_dev);
 }
 
-struct bus_type scmi_bus_type = {
+const struct bus_type scmi_bus_type = {
 	.name =	"scmi_protocol",
 	.match = scmi_dev_match,
 	.probe = scmi_dev_probe,
@@ -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);