diff options
Diffstat (limited to 'include/linux/surface_aggregator/device.h')
| -rw-r--r-- | include/linux/surface_aggregator/device.h | 222 |
1 files changed, 219 insertions, 3 deletions
diff --git a/include/linux/surface_aggregator/device.h b/include/linux/surface_aggregator/device.h index f636c5310321..46c45d1b6368 100644 --- a/include/linux/surface_aggregator/device.h +++ b/include/linux/surface_aggregator/device.h @@ -15,6 +15,7 @@ #include <linux/device.h> #include <linux/mod_devicetable.h> +#include <linux/property.h> #include <linux/types.h> #include <linux/surface_aggregator/controller.h> @@ -148,17 +149,30 @@ struct ssam_device_uid { #define SSAM_SDEV(cat, tid, iid, fun) \ SSAM_DEVICE(SSAM_DOMAIN_SERIALHUB, SSAM_SSH_TC_##cat, tid, iid, fun) +/* + * enum ssam_device_flags - Flags for SSAM client devices. + * @SSAM_DEVICE_HOT_REMOVED_BIT: + * The device has been hot-removed. Further communication with it may time + * out and should be avoided. + */ +enum ssam_device_flags { + SSAM_DEVICE_HOT_REMOVED_BIT = 0, +}; + /** * struct ssam_device - SSAM client device. - * @dev: Driver model representation of the device. - * @ctrl: SSAM controller managing this device. - * @uid: UID identifying the device. + * @dev: Driver model representation of the device. + * @ctrl: SSAM controller managing this device. + * @uid: UID identifying the device. + * @flags: Device state flags, see &enum ssam_device_flags. */ struct ssam_device { struct device dev; struct ssam_controller *ctrl; struct ssam_device_uid uid; + + unsigned long flags; }; /** @@ -177,6 +191,8 @@ struct ssam_device_driver { void (*remove)(struct ssam_device *sdev); }; +#ifdef CONFIG_SURFACE_AGGREGATOR_BUS + extern struct bus_type ssam_bus_type; extern const struct device_type ssam_device_type; @@ -193,6 +209,15 @@ static inline bool is_ssam_device(struct device *d) return d->type == &ssam_device_type; } +#else /* CONFIG_SURFACE_AGGREGATOR_BUS */ + +static inline bool is_ssam_device(struct device *d) +{ + return false; +} + +#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */ + /** * to_ssam_device() - Casts the given device to a SSAM client device. * @d: The device to cast. @@ -241,6 +266,35 @@ int ssam_device_add(struct ssam_device *sdev); void ssam_device_remove(struct ssam_device *sdev); /** + * ssam_device_mark_hot_removed() - Mark the given device as hot-removed. + * @sdev: The device to mark as hot-removed. + * + * Mark the device as having been hot-removed. This signals drivers using the + * device that communication with the device should be avoided and may lead to + * timeouts. + */ +static inline void ssam_device_mark_hot_removed(struct ssam_device *sdev) +{ + dev_dbg(&sdev->dev, "marking device as hot-removed\n"); + set_bit(SSAM_DEVICE_HOT_REMOVED_BIT, &sdev->flags); +} + +/** + * ssam_device_is_hot_removed() - Check if the given device has been + * hot-removed. + * @sdev: The device to check. + * + * Checks if the given device has been marked as hot-removed. See + * ssam_device_mark_hot_removed() for more details. + * + * Return: Returns ``true`` if the device has been marked as hot-removed. + */ +static inline bool ssam_device_is_hot_removed(struct ssam_device *sdev) +{ + return test_bit(SSAM_DEVICE_HOT_REMOVED_BIT, &sdev->flags); +} + +/** * ssam_device_get() - Increment reference count of SSAM client device. * @sdev: The device to increment the reference count of. * @@ -319,6 +373,66 @@ void ssam_device_driver_unregister(struct ssam_device_driver *d); ssam_device_driver_unregister) +/* -- Helpers for controller and hub devices. ------------------------------- */ + +#ifdef CONFIG_SURFACE_AGGREGATOR_BUS + +int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node); +void ssam_remove_clients(struct device *dev); + +#else /* CONFIG_SURFACE_AGGREGATOR_BUS */ + +static inline int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + return 0; +} + +static inline void ssam_remove_clients(struct device *dev) {} + +#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */ + +/** + * ssam_register_clients() - Register all client devices defined under the + * given parent device. + * @dev: The parent device under which clients should be registered. + * @ctrl: The controller with which client should be registered. + * + * Register all clients that have via firmware nodes been defined as children + * of the given (parent) device. The respective child firmware nodes will be + * associated with the correspondingly created child devices. + * + * The given controller will be used to instantiate the new devices. See + * ssam_device_add() for details. + * + * Return: Returns zero on success, nonzero on failure. + */ +static inline int ssam_register_clients(struct device *dev, struct ssam_controller *ctrl) +{ + return __ssam_register_clients(dev, ctrl, dev_fwnode(dev)); +} + +/** + * ssam_device_register_clients() - Register all client devices defined under + * the given SSAM parent device. + * @sdev: The parent device under which clients should be registered. + * + * Register all clients that have via firmware nodes been defined as children + * of the given (parent) device. The respective child firmware nodes will be + * associated with the correspondingly created child devices. + * + * The controller used by the parent device will be used to instantiate the new + * devices. See ssam_device_add() for details. + * + * Return: Returns zero on success, nonzero on failure. + */ +static inline int ssam_device_register_clients(struct ssam_device *sdev) +{ + return ssam_register_clients(&sdev->dev, sdev->ctrl); +} + + /* -- Helpers for client-device requests. ----------------------------------- */ /** @@ -421,4 +535,106 @@ void ssam_device_driver_unregister(struct ssam_device_driver *d); sdev->uid.instance, ret); \ } +/** + * SSAM_DEFINE_SYNC_REQUEST_CL_WR() - Define synchronous client-device SAM + * request function with argument and return value. + * @name: Name of the generated function. + * @atype: Type of the request's argument. + * @rtype: Type of the request's return value. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by @spec, + * with the request taking an argument of type @atype and having a return value + * of type @rtype. Device specifying parameters are not hard-coded, but instead + * are provided via the client device, specifically its UID, supplied when + * calling this function. The generated function takes care of setting up the + * request struct, buffer allocation, as well as execution of the request + * itself, returning once the request has been fully completed. The required + * transport buffer will be allocated on the stack. + * + * The generated function is defined as ``static int name(struct ssam_device + * *sdev, const atype *arg, rtype *ret)``, returning the status of the request, + * which is zero on success and negative on failure. The ``sdev`` parameter + * specifies both the target device of the request and by association the + * controller via which the request is sent. The request's argument is + * specified via the ``arg`` pointer. The request's return value is written to + * the memory pointed to by the ``ret`` parameter. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_CL_WR(name, atype, rtype, spec...) \ + SSAM_DEFINE_SYNC_REQUEST_MD_WR(__raw_##name, atype, rtype, spec) \ + static int name(struct ssam_device *sdev, const atype *arg, rtype *ret) \ + { \ + return __raw_##name(sdev->ctrl, sdev->uid.target, \ + sdev->uid.instance, arg, ret); \ + } + + +/* -- Helpers for client-device notifiers. ---------------------------------- */ + +/** + * ssam_device_notifier_register() - Register an event notifier for the + * specified client device. + * @sdev: The device the notifier should be registered on. + * @n: The event notifier to register. + * + * Register an event notifier. Increment the usage counter of the associated + * SAM event if the notifier is not marked as an observer. If the event is not + * marked as an observer and is currently not enabled, it will be enabled + * during this call. If the notifier is marked as an observer, no attempt will + * be made at enabling any event and no reference count will be modified. + * + * Notifiers marked as observers do not need to be associated with one specific + * event, i.e. as long as no event matching is performed, only the event target + * category needs to be set. + * + * Return: Returns zero on success, %-ENOSPC if there have already been + * %INT_MAX notifiers for the event ID/type associated with the notifier block + * registered, %-ENOMEM if the corresponding event entry could not be + * allocated, %-ENODEV if the device is marked as hot-removed. If this is the + * first time that a notifier block is registered for the specific associated + * event, returns the status of the event-enable EC-command. + */ +static inline int ssam_device_notifier_register(struct ssam_device *sdev, + struct ssam_event_notifier *n) +{ + /* + * Note that this check does not provide any guarantees whatsoever as + * hot-removal could happen at any point and we can't protect against + * it. Nevertheless, if we can detect hot-removal, bail early to avoid + * communication timeouts. + */ + if (ssam_device_is_hot_removed(sdev)) + return -ENODEV; + + return ssam_notifier_register(sdev->ctrl, n); +} + +/** + * ssam_device_notifier_unregister() - Unregister an event notifier for the + * specified client device. + * @sdev: The device the notifier has been registered on. + * @n: The event notifier to unregister. + * + * Unregister an event notifier. Decrement the usage counter of the associated + * SAM event if the notifier is not marked as an observer. If the usage counter + * reaches zero, the event will be disabled. + * + * In case the device has been marked as hot-removed, the event will not be + * disabled on the EC, as in those cases any attempt at doing so may time out. + * + * Return: Returns zero on success, %-ENOENT if the given notifier block has + * not been registered on the controller. If the given notifier block was the + * last one associated with its specific event, returns the status of the + * event-disable EC-command. + */ +static inline int ssam_device_notifier_unregister(struct ssam_device *sdev, + struct ssam_event_notifier *n) +{ + return __ssam_notifier_unregister(sdev->ctrl, n, + !ssam_device_is_hot_removed(sdev)); +} + #endif /* _LINUX_SURFACE_AGGREGATOR_DEVICE_H */ |