From 0e8512fab9fd6d78e88931c02a43b04d15566d6b Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Fri, 4 Jun 2021 15:47:49 +0200 Subject: platform/surface: aggregator: Allow registering notifiers without enabling events Currently, each SSAM event notifier is directly tied to one group of events. This makes sense as registering a notifier will automatically take care of enabling the corresponding event group and normally drivers only need notifications for a very limited number of events, associated with different callbacks for each group. However, there are rare cases, especially for debugging, when we want to get notifications for a whole event target category instead of just a single group of events in that category. Registering multiple notifiers, i.e. one per group, may be infeasible due to two issues: a) we might not know every event enable/disable specification as some events are auto-enabled by the EC and b) forwarding this to the same callback will lead to duplicate events as we might not know the full event specification to perform the appropriate filtering. This commit introduces observer-notifiers, which are notifiers that are not tied to a specific event group and do not attempt to manage any events. In other words, they can be registered without enabling any event group or incrementing the corresponding reference count and just act as silent observers, listening to all currently/previously enabled events based on their match-specification. Essentially, this allows us to register one single notifier for a full event target category, meaning that we can process all events of that target category in a single callback without duplication. Specifically, this will be used in the cdev debug interface to forward events to user-space via a device file from which the events can be read. Signed-off-by: Maximilian Luz Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20210604134755.535590-2-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- include/linux/surface_aggregator/controller.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux/surface_aggregator/controller.h') diff --git a/include/linux/surface_aggregator/controller.h b/include/linux/surface_aggregator/controller.h index 0806796eabcb..cf4bb48a850e 100644 --- a/include/linux/surface_aggregator/controller.h +++ b/include/linux/surface_aggregator/controller.h @@ -795,6 +795,20 @@ enum ssam_event_mask { #define SSAM_EVENT_REGISTRY_REG \ SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, 0x02, 0x01, 0x02) +/** + * enum ssam_event_notifier_flags - Flags for event notifiers. + * @SSAM_EVENT_NOTIFIER_OBSERVER: + * The corresponding notifier acts as observer. Registering a notifier + * with this flag set will not attempt to enable any event. Equally, + * unregistering will not attempt to disable any event. Note that a + * notifier with this flag may not even correspond to a certain event at + * all, only to a specific event target category. Event matching will not + * be influenced by this flag. + */ +enum ssam_event_notifier_flags { + SSAM_EVENT_NOTIFIER_OBSERVER = BIT(0), +}; + /** * struct ssam_event_notifier - Notifier block for SSAM events. * @base: The base notifier block with callback function and priority. @@ -803,6 +817,7 @@ enum ssam_event_mask { * @event.id: ID specifying the event. * @event.mask: Flags determining how events are matched to the notifier. * @event.flags: Flags used for enabling the event. + * @flags: Notifier flags (see &enum ssam_event_notifier_flags). */ struct ssam_event_notifier { struct ssam_notifier_block base; @@ -813,6 +828,8 @@ struct ssam_event_notifier { enum ssam_event_mask mask; u8 flags; } event; + + unsigned long flags; }; int ssam_notifier_register(struct ssam_controller *ctrl, -- cgit v1.2.3 From 4b38a1dcf378f5075884b54dc5afeb9d0dfe7681 Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Fri, 4 Jun 2021 15:47:50 +0200 Subject: platform/surface: aggregator: Allow enabling of events without notifiers We can already enable and disable SAM events via one of two ways: either via a (non-observer) notifier tied to a specific event group, or a generic event enable/disable request. In some instances, however, neither method may be desirable. The first method will tie the event enable request to a specific notifier, however, when we want to receive notifications for multiple event groups of the same target category and forward this to the same notifier callback, we may receive duplicate events, i.e. one event per registered notifier. The second method will bypass the internal reference counting mechanism, meaning that a disable request will disable the event regardless of any other client driver using it, which may break the functionality of that driver. To address this problem, add new functions that allow enabling and disabling of events via the event reference counting mechanism built into the controller, without needing to register a notifier. This can then be used in combination with observer notifiers to process multiple events of the same target category without duplication in the same callback function. Signed-off-by: Maximilian Luz Link: https://lore.kernel.org/r/20210604134755.535590-3-luzmaximilian@gmail.com Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- include/linux/surface_aggregator/controller.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/surface_aggregator/controller.h') diff --git a/include/linux/surface_aggregator/controller.h b/include/linux/surface_aggregator/controller.h index cf4bb48a850e..7965bdc669c5 100644 --- a/include/linux/surface_aggregator/controller.h +++ b/include/linux/surface_aggregator/controller.h @@ -838,4 +838,12 @@ int ssam_notifier_register(struct ssam_controller *ctrl, int ssam_notifier_unregister(struct ssam_controller *ctrl, struct ssam_event_notifier *n); +int ssam_controller_event_enable(struct ssam_controller *ctrl, + struct ssam_event_registry reg, + struct ssam_event_id id, u8 flags); + +int ssam_controller_event_disable(struct ssam_controller *ctrl, + struct ssam_event_registry reg, + struct ssam_event_id id, u8 flags); + #endif /* _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H */ -- cgit v1.2.3 From b2763358feb28590f6b52a4c95c94a645dadfb26 Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Fri, 4 Jun 2021 15:47:51 +0200 Subject: platform/surface: aggregator: Update copyright It's 2021, update the copyright accordingly. Signed-off-by: Maximilian Luz Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20210604134755.535590-4-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- include/linux/surface_aggregator/controller.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/surface_aggregator/controller.h') diff --git a/include/linux/surface_aggregator/controller.h b/include/linux/surface_aggregator/controller.h index 7965bdc669c5..068e1982ad37 100644 --- a/include/linux/surface_aggregator/controller.h +++ b/include/linux/surface_aggregator/controller.h @@ -6,7 +6,7 @@ * managing access and communication to and from the SSAM EC, as well as main * communication structures and definitions. * - * Copyright (C) 2019-2020 Maximilian Luz + * Copyright (C) 2019-2021 Maximilian Luz */ #ifndef _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H -- cgit v1.2.3