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/* 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 <luzmaximilian@gmail.com> */ #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 {	SSAM_EVENT_SEQUENCED = BIT(0),}; /** * 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 {	u8 target_category;	u8 target_id;	u8 command_id;	u8 instance_id;	u16 length;	u8 data[] __counted_by(length);}; /** * 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 {	SSAM_REQUEST_HAS_RESPONSE = BIT(0),	SSAM_REQUEST_UNSEQUENCED  = BIT(1),}; /** * 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 {	u8 target_category;	u8 target_id;	u8 command_id;	u8 instance_id;	u16 flags;	u16 length;	const u8 *payload;}; /** * 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 {	size_t capacity;	size_t length;	u8 *pointer;}; 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 {	struct ssh_request base;	struct completion comp;	struct ssam_response *resp;	int status;}; 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){	ssh_request_set_data(&rqst->base, ptr, 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){	rqst->resp = 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){	wait_for_completion(&rqst->comp);	return rqst->status;} 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)		\	({									\		u8 __data[SSH_COMMAND_MESSAGE_LENGTH(payload_len)];		\		struct ssam_span __buf = { &__data[0], ARRAY_SIZE(__data) };	\										\		ssam_request_do_sync_with_buffer(ctrl, rqst, rsp, &__buf);	\	}) /** * __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...)				\	({								\		int __i, __s = 0;					\									\		for (__i = (n); __i > 0; __i--) {			\			__s = request(args);				\			if (__s != -ETIMEDOUT && __s != -EREMOTEIO)	\				break;					\		}							\		__s;							\	}) /** * 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...) \	__ssam_retry(request, 3, 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 {	u8 target_category;	u8 target_id;	u8 command_id;	u8 instance_id;	u8 flags;}; /** * 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 {	u8 target_category;	u8 command_id;	u8 flags;}; /** * 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...)				\	static int name(struct ssam_controller *ctrl)				\	{									\		struct ssam_request_spec s = (struct ssam_request_spec)spec;	\		struct ssam_request rqst;					\										\		rqst.target_category = s.target_category;			\		rqst.target_id = s.target_id;					\		rqst.command_id = s.command_id;					\		rqst.instance_id = s.instance_id;				\		rqst.flags = s.flags;						\		rqst.length = 0;						\		rqst.payload = NULL;						\										\		return ssam_request_do_sync_onstack(ctrl, &rqst, NULL, 0);	\	} /** * 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...)			\	static int name(struct ssam_controller *ctrl, const atype *arg)		\	{									\		struct ssam_request_spec s = (struct ssam_request_spec)spec;	\		struct ssam_request rqst;					\										\		rqst.target_category = s.target_category;			\		rqst.target_id = s.target_id;					\		rqst.command_id = s.command_id;					\		rqst.instance_id = s.instance_id;				\		rqst.flags = s.flags;						\		rqst.length = sizeof(atype);					\		rqst.payload = (u8 *)arg;					\										\		return ssam_request_do_sync_onstack(ctrl, &rqst, NULL,		\						    sizeof(atype));		\	} /** * 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...)			\	static int name(struct ssam_controller *ctrl, rtype *ret)		\	{									\		struct ssam_request_spec s = (struct ssam_request_spec)spec;	\		struct ssam_request rqst;					\		struct ssam_response rsp;					\		int status;							\										\		rqst.target_category = s.target_category;			\		rqst.target_id = s.target_id;					\		rqst.command_id = s.command_id;					\		rqst.instance_id = s.instance_id;				\		rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE;		\		rqst.length = 0;						\		rqst.payload = NULL;						\										\		rsp.capacity = sizeof(rtype);					\		rsp.length = 0;							\		rsp.pointer = (u8 *)ret;					\										\		status = ssam_request_do_sync_onstack(ctrl, &rqst, &rsp, 0);	\		if (status)							\			return status;						\										\		if (rsp.length != sizeof(rtype)) {				\			struct device *dev = ssam_controller_device(ctrl);	\			dev_err(dev,						\				"rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \				sizeof(rtype), rsp.length, rqst.target_category,\				rqst.command_id);				\			return -EIO;						\		}								\										\		return 0;							\	} /** * 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...)		\	static int name(struct ssam_controller *ctrl, const atype *arg, rtype *ret) \	{									\		struct ssam_request_spec s = (struct ssam_request_spec)spec;	\

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