/* SPDX-License-Identifier: GPL-2.0+ */ /* * Surface System Aggregator Module (SSAM) controller interface. * * Main communication interface for the SSAM EC. Provides a controller * managing access and communication to and from the SSAM EC, as well as main * communication structures and definitions. * * Copyright (C) 2019-2021 Maximilian Luz <[email protected]> */ #ifndef _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H #define _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H #include <linux/completion.h> #include <linux/device.h> #include <linux/types.h> #include <linux/surface_aggregator/serial_hub.h> /* -- Main data types and definitions --------------------------------------- */ /** * enum ssam_event_flags - Flags for enabling/disabling SAM events * @SSAM_EVENT_SEQUENCED: The event will be sent via a sequenced data frame. */ enum ssam_event_flags { … }; /** * struct ssam_event - SAM event sent from the EC to the host. * @target_category: Target category of the event source. See &enum ssam_ssh_tc. * @target_id: Target ID of the event source. * @command_id: Command ID of the event. * @instance_id: Instance ID of the event source. * @length: Length of the event payload in bytes. * @data: Event payload data. */ struct ssam_event { … }; /** * enum ssam_request_flags - Flags for SAM requests. * * @SSAM_REQUEST_HAS_RESPONSE: * Specifies that the request expects a response. If not set, the request * will be directly completed after its underlying packet has been * transmitted. If set, the request transport system waits for a response * of the request. * * @SSAM_REQUEST_UNSEQUENCED: * Specifies that the request should be transmitted via an unsequenced * packet. If set, the request must not have a response, meaning that this * flag and the %SSAM_REQUEST_HAS_RESPONSE flag are mutually exclusive. */ enum ssam_request_flags { … }; /** * struct ssam_request - SAM request description. * @target_category: Category of the request's target. See &enum ssam_ssh_tc. * @target_id: ID of the request's target. * @command_id: Command ID of the request. * @instance_id: Instance ID of the request's target. * @flags: Flags for the request. See &enum ssam_request_flags. * @length: Length of the request payload in bytes. * @payload: Request payload data. * * This struct fully describes a SAM request with payload. It is intended to * help set up the actual transport struct, e.g. &struct ssam_request_sync, * and specifically its raw message data via ssam_request_write_data(). */ struct ssam_request { … }; /** * struct ssam_response - Response buffer for SAM request. * @capacity: Capacity of the buffer, in bytes. * @length: Length of the actual data stored in the memory pointed to by * @pointer, in bytes. Set by the transport system. * @pointer: Pointer to the buffer's memory, storing the response payload data. */ struct ssam_response { … }; struct ssam_controller; struct ssam_controller *ssam_get_controller(void); struct ssam_controller *ssam_client_bind(struct device *client); int ssam_client_link(struct ssam_controller *ctrl, struct device *client); struct device *ssam_controller_device(struct ssam_controller *c); struct ssam_controller *ssam_controller_get(struct ssam_controller *c); void ssam_controller_put(struct ssam_controller *c); void ssam_controller_statelock(struct ssam_controller *c); void ssam_controller_stateunlock(struct ssam_controller *c); ssize_t ssam_request_write_data(struct ssam_span *buf, struct ssam_controller *ctrl, const struct ssam_request *spec); /* -- Synchronous request interface. ---------------------------------------- */ /** * struct ssam_request_sync - Synchronous SAM request struct. * @base: Underlying SSH request. * @comp: Completion used to signal full completion of the request. After the * request has been submitted, this struct may only be modified or * deallocated after the completion has been signaled. * request has been submitted, * @resp: Buffer to store the response. * @status: Status of the request, set after the base request has been * completed or has failed. */ struct ssam_request_sync { … }; int ssam_request_sync_alloc(size_t payload_len, gfp_t flags, struct ssam_request_sync **rqst, struct ssam_span *buffer); void ssam_request_sync_free(struct ssam_request_sync *rqst); int ssam_request_sync_init(struct ssam_request_sync *rqst, enum ssam_request_flags flags); /** * ssam_request_sync_set_data - Set message data of a synchronous request. * @rqst: The request. * @ptr: Pointer to the request message data. * @len: Length of the request message data. * * Set the request message data of a synchronous request. The provided buffer * needs to live until the request has been completed. */ static inline void ssam_request_sync_set_data(struct ssam_request_sync *rqst, u8 *ptr, size_t len) { … } /** * ssam_request_sync_set_resp - Set response buffer of a synchronous request. * @rqst: The request. * @resp: The response buffer. * * Sets the response buffer of a synchronous request. This buffer will store * the response of the request after it has been completed. May be %NULL if no * response is expected. */ static inline void ssam_request_sync_set_resp(struct ssam_request_sync *rqst, struct ssam_response *resp) { … } int ssam_request_sync_submit(struct ssam_controller *ctrl, struct ssam_request_sync *rqst); /** * ssam_request_sync_wait - Wait for completion of a synchronous request. * @rqst: The request to wait for. * * Wait for completion and release of a synchronous request. After this * function terminates, the request is guaranteed to have left the transport * system. After successful submission of a request, this function must be * called before accessing the response of the request, freeing the request, * or freeing any of the buffers associated with the request. * * This function must not be called if the request has not been submitted yet * and may lead to a deadlock/infinite wait if a subsequent request submission * fails in that case, due to the completion never triggering. * * Return: Returns the status of the given request, which is set on completion * of the packet. This value is zero on success and negative on failure. */ static inline int ssam_request_sync_wait(struct ssam_request_sync *rqst) { … } int ssam_request_do_sync(struct ssam_controller *ctrl, const struct ssam_request *spec, struct ssam_response *rsp); int ssam_request_do_sync_with_buffer(struct ssam_controller *ctrl, const struct ssam_request *spec, struct ssam_response *rsp, struct ssam_span *buf); /** * ssam_request_do_sync_onstack - Execute a synchronous request on the stack. * @ctrl: The controller via which the request is submitted. * @rqst: The request specification. * @rsp: The response buffer. * @payload_len: The (maximum) request payload length. * * Allocates a synchronous request with specified payload length on the stack, * fully initializes it via the provided request specification, submits it, * and finally waits for its completion before returning its status. This * helper macro essentially allocates the request message buffer on the stack * and then calls ssam_request_do_sync_with_buffer(). * * Note: The @payload_len parameter specifies the maximum payload length, used * for buffer allocation. The actual payload length may be smaller. * * Return: Returns the status of the request or any failure during setup, i.e. * zero on success and a negative value on failure. */ #define ssam_request_do_sync_onstack(ctrl, rqst, rsp, payload_len) … /** * __ssam_retry - Retry request in case of I/O errors or timeouts. * @request: The request function to execute. Must return an integer. * @n: Number of tries. * @args: Arguments for the request function. * * Executes the given request function, i.e. calls @request. In case the * request returns %-EREMOTEIO (indicates I/O error) or %-ETIMEDOUT (request * or underlying packet timed out), @request will be re-executed again, up to * @n times in total. * * Return: Returns the return value of the last execution of @request. */ #define __ssam_retry(request, n, args...) … /** * ssam_retry - Retry request in case of I/O errors or timeouts up to three * times in total. * @request: The request function to execute. Must return an integer. * @args: Arguments for the request function. * * Executes the given request function, i.e. calls @request. In case the * request returns %-EREMOTEIO (indicates I/O error) or -%ETIMEDOUT (request * or underlying packet timed out), @request will be re-executed again, up to * three times in total. * * See __ssam_retry() for a more generic macro for this purpose. * * Return: Returns the return value of the last execution of @request. */ #define ssam_retry(request, args...) … /** * struct ssam_request_spec - Blue-print specification of SAM request. * @target_category: Category of the request's target. See &enum ssam_ssh_tc. * @target_id: ID of the request's target. * @command_id: Command ID of the request. * @instance_id: Instance ID of the request's target. * @flags: Flags for the request. See &enum ssam_request_flags. * * Blue-print specification for a SAM request. This struct describes the * unique static parameters of a request (i.e. type) without specifying any of * its instance-specific data (e.g. payload). It is intended to be used as base * for defining simple request functions via the * ``SSAM_DEFINE_SYNC_REQUEST_x()`` family of macros. */ struct ssam_request_spec { … }; /** * struct ssam_request_spec_md - Blue-print specification for multi-device SAM * request. * @target_category: Category of the request's target. See &enum ssam_ssh_tc. * @command_id: Command ID of the request. * @flags: Flags for the request. See &enum ssam_request_flags. * * Blue-print specification for a multi-device SAM request, i.e. a request * that is applicable to multiple device instances, described by their * individual target and instance IDs. This struct describes the unique static * parameters of a request (i.e. type) without specifying any of its * instance-specific data (e.g. payload) and without specifying any of its * device specific IDs (i.e. target and instance ID). It is intended to be * used as base for defining simple multi-device request functions via the * ``SSAM_DEFINE_SYNC_REQUEST_MD_x()`` and ``SSAM_DEFINE_SYNC_REQUEST_CL_x()`` * families of macros. */ struct ssam_request_spec_md { … }; /** * SSAM_DEFINE_SYNC_REQUEST_N() - Define synchronous SAM request function * with neither argument nor return value. * @name: Name of the generated function. * @spec: Specification (&struct ssam_request_spec) defining the request. * * Defines a function executing the synchronous SAM request specified by * @spec, with the request having neither argument nor return value. The * generated function takes care of setting up the request struct and 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_controller *ctrl)``, returning the status of the request, which is * zero on success and negative on failure. The ``ctrl`` parameter is the * controller via which the request is being sent. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_N(name, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_W() - Define synchronous SAM request function with * argument. * @name: Name of the generated function. * @atype: Type of the request's argument. * @spec: Specification (&struct ssam_request_spec) 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 no * return value. 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_controller *ctrl, const atype *arg)``, returning the status of the * request, which is zero on success and negative on failure. The ``ctrl`` * parameter is the controller via which the request is sent. The request * argument is specified via the ``arg`` pointer. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_W(name, atype, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_R() - Define synchronous SAM request function with * return value. * @name: Name of the generated function. * @rtype: Type of the request's return value. * @spec: Specification (&struct ssam_request_spec) defining the request. * * Defines a function executing the synchronous SAM request specified by * @spec, with the request taking no argument but having a return value of * type @rtype. The generated function takes care of setting up the request * and response structs, 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_controller *ctrl, rtype *ret)``, returning the status of the request, * which is zero on success and negative on failure. The ``ctrl`` parameter is * the controller via which the request is sent. The request's return value is * written to the memory pointed to by the ``ret`` parameter. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_R(name, rtype, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_WR() - Define synchronous SAM request function with * both 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) 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. The generated function takes care of setting up the request * and response structs, 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_controller *ctrl, const atype *arg, rtype *ret)``, returning the status * of the request, which is zero on success and negative on failure. The * ``ctrl`` parameter is the controller via which the request is sent. The * request 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_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_WR(name, atype, rtype, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_MD_N() - Define synchronous multi-device SAM * request function with neither argument nor return value. * @name: Name of the generated function. * @spec: Specification (&struct ssam_request_spec_md) defining the request. * * Defines a function executing the synchronous SAM request specified by * @spec, with the request having neither argument nor return value. Device * specifying parameters are not hard-coded, but instead must be provided to * the 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_controller *ctrl, u8 tid, u8 iid)``, returning the status of the * request, which is zero on success and negative on failure. The ``ctrl`` * parameter is the controller via which the request is sent, ``tid`` the * target ID for the request, and ``iid`` the instance ID. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_MD_N(name, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_MD_W() - Define synchronous multi-device SAM * request function with argument. * @name: Name of the generated function. * @atype: Type of the request's argument. * @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 no * return value. Device specifying parameters are not hard-coded, but instead * must be provided to the 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_controller *ctrl, u8 tid, u8 iid, const atype *arg)``, returning the * status of the request, which is zero on success and negative on failure. * The ``ctrl`` parameter is the controller via which the request is sent, * ``tid`` the target ID for the request, and ``iid`` the instance ID. The * request argument is specified via the ``arg`` pointer. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_MD_W(name, atype, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_MD_R() - Define synchronous multi-device SAM * request function with return value. * @name: Name of the generated function. * @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 no argument but having a return value of * type @rtype. Device specifying parameters are not hard-coded, but instead * must be provided to the function. The generated function takes care of * setting up the request and response structs, 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_controller *ctrl, u8 tid, u8 iid, rtype *ret)``, returning the status * of the request, which is zero on success and negative on failure. The * ``ctrl`` parameter is the controller via which the request is sent, ``tid`` * the target ID for the request, and ``iid`` the instance ID. The request's * return value is written to the memory pointed to by the ``ret`` parameter. * * Refer to ssam_request_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_MD_R(name, rtype, spec...) … /** * SSAM_DEFINE_SYNC_REQUEST_MD_WR() - Define synchronous multi-device SAM * request function with both 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 * must be provided to the function. The generated function takes care of * setting up the request and response structs, 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_controller *ctrl, u8 tid, u8 iid, const atype *arg, rtype *ret)``, * returning the status of the request, which is zero on success and negative * on failure. The ``ctrl`` parameter is the controller via which the request * is sent, ``tid`` the target ID for the request, and ``iid`` the instance ID. * The request 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_do_sync_onstack() for more details on the behavior of * the generated function. */ #define SSAM_DEFINE_SYNC_REQUEST_MD_WR(name, atype, rtype, spec...) … /* -- Event notifier/callbacks. --------------------------------------------- */ #define SSAM_NOTIF_STATE_SHIFT … #define SSAM_NOTIF_STATE_MASK … /** * enum ssam_notif_flags - Flags used in return values from SSAM notifier * callback functions. * * @SSAM_NOTIF_HANDLED: * Indicates that the notification has been handled. This flag should be * set by the handler if the handler can act/has acted upon the event * provided to it. This flag should not be set if the handler is not a * primary handler intended for the provided event. * * If this flag has not been set by any handler after the notifier chain * has been traversed, a warning will be emitted, stating that the event * has not been handled. * * @SSAM_NOTIF_STOP: * Indicates that the notifier traversal should stop. If this flag is * returned from a notifier callback, notifier chain traversal will * immediately stop and any remaining notifiers will not be called. This * flag is automatically set when ssam_notifier_from_errno() is called * with a negative error value. */ enum ssam_notif_flags { … }; struct ssam_event_notifier; ssam_notifier_fn_t; /** * struct ssam_notifier_block - Base notifier block for SSAM event * notifications. * @node: The node for the list of notifiers. * @fn: The callback function of this notifier. This function takes the * respective notifier block and event as input and should return * a notifier value, which can either be obtained from the flags * provided in &enum ssam_notif_flags, converted from a standard * error value via ssam_notifier_from_errno(), or a combination of * both (e.g. ``ssam_notifier_from_errno(e) | SSAM_NOTIF_HANDLED``). * @priority: Priority value determining the order in which notifier callbacks * will be called. A higher value means higher priority, i.e. the * associated callback will be executed earlier than other (lower * priority) callbacks. */ struct ssam_notifier_block { … }; /** * ssam_notifier_from_errno() - Convert standard error value to notifier * return code. * @err: The error code to convert, must be negative (in case of failure) or * zero (in case of success). * * Return: Returns the notifier return value obtained by converting the * specified @err value. In case @err is negative, the %SSAM_NOTIF_STOP flag * will be set, causing notifier call chain traversal to abort. */ static inline u32 ssam_notifier_from_errno(int err) { … } /** * ssam_notifier_to_errno() - Convert notifier return code to standard error * value. * @ret: The notifier return value to convert. * * Return: Returns the negative error value encoded in @ret or zero if @ret * indicates success. */ static inline int ssam_notifier_to_errno(u32 ret) { … } /* -- Event/notification registry. ------------------------------------------ */ /** * struct ssam_event_registry - Registry specification used for enabling events. * @target_category: Target category for the event registry requests. * @target_id: Target ID for the event registry requests. * @cid_enable: Command ID for the event-enable request. * @cid_disable: Command ID for the event-disable request. * * This struct describes a SAM event registry via the minimal collection of * SAM IDs specifying the requests to use for enabling and disabling an event. * The individual event to be enabled/disabled itself is specified via &struct * ssam_event_id. */ struct ssam_event_registry { … }; /** * struct ssam_event_id - Unique event ID used for enabling events. * @target_category: Target category of the event source. * @instance: Instance ID of the event source. * * This struct specifies the event to be enabled/disabled via an externally * provided registry. It does not specify the registry to be used itself, this * is done via &struct ssam_event_registry. */ struct ssam_event_id { … }; /** * enum ssam_event_mask - Flags specifying how events are matched to notifiers. * * @SSAM_EVENT_MASK_NONE: * Run the callback for any event with matching target category. Do not * do any additional filtering. * * @SSAM_EVENT_MASK_TARGET: * In addition to filtering by target category, only execute the notifier * callback for events with a target ID matching to the one of the * registry used for enabling/disabling the event. * * @SSAM_EVENT_MASK_INSTANCE: * In addition to filtering by target category, only execute the notifier * callback for events with an instance ID matching to the instance ID * used when enabling the event. * * @SSAM_EVENT_MASK_STRICT: * Do all the filtering above. */ enum ssam_event_mask { … }; /** * SSAM_EVENT_REGISTRY() - Define a new event registry. * @tc: Target category for the event registry requests. * @tid: Target ID for the event registry requests. * @cid_en: Command ID for the event-enable request. * @cid_dis: Command ID for the event-disable request. * * Return: Returns the &struct ssam_event_registry specified by the given * parameters. */ #define SSAM_EVENT_REGISTRY(tc, tid, cid_en, cid_dis) … #define SSAM_EVENT_REGISTRY_SAM … #define SSAM_EVENT_REGISTRY_KIP … #define SSAM_EVENT_REGISTRY_REG(tid) … /** * 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 { … }; /** * struct ssam_event_notifier - Notifier block for SSAM events. * @base: The base notifier block with callback function and priority. * @event: The event for which this block will receive notifications. * @event.reg: Registry via which the event will be enabled/disabled. * @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 { … }; int ssam_notifier_register(struct ssam_controller *ctrl, struct ssam_event_notifier *n); int __ssam_notifier_unregister(struct ssam_controller *ctrl, struct ssam_event_notifier *n, bool disable); /** * ssam_notifier_unregister() - Unregister an event notifier. * @ctrl: The controller 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. * * 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_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 */
Codebase Browser
linux