/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
* Surface System Aggregator Module (SSAM) user-space EC interface.
*
* Definitions, structs, and IOCTLs for the /dev/surface/aggregator misc
* device. This device provides direct user-space access to the SSAM EC.
* Intended for debugging and development.
*
* Copyright (C) 2020-2021 Maximilian Luz <luzmaximilian@gmail.com>
*/
#ifndef _LINUX_SURFACE_AGGREGATOR_CDEV_H
#define _LINUX_SURFACE_AGGREGATOR_CDEV_H
#include <linux/ioctl.h>
#include <linux/types.h>
/**
* enum ssam_cdev_request_flags - Request flags for SSAM cdev request IOCTL.
*
* @SSAM_CDEV_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_CDEV_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_CDEV_REQUEST_HAS_RESPONSE flag are mutually
* exclusive.
*/
enum ssam_cdev_request_flags {
SSAM_CDEV_REQUEST_HAS_RESPONSE = 0x01,
SSAM_CDEV_REQUEST_UNSEQUENCED = 0x02,
};
/**
* struct ssam_cdev_request - Controller request IOCTL argument.
* @target_category: Target category of the SAM request.
* @target_id: Target ID of the SAM request.
* @command_id: Command ID of the SAM request.
* @instance_id: Instance ID of the SAM request.
* @flags: Request flags (see &enum ssam_cdev_request_flags).
* @status: Request status (output).
* @payload: Request payload (input data).
* @payload.data: Pointer to request payload data.
* @payload.length: Length of request payload data (in bytes).
* @response: Request response (output data).
* @response.data: Pointer to response buffer.
* @response.length: On input: Capacity of response buffer (in bytes).
* On output: Length of request response (number of bytes
* in the buffer that are actually used).
*/
struct ssam_cdev_request {
__u8 target_category;
__u8 target_id;
__u8 command_id;
__u8 instance_id;
__u16 flags;
__s16 status;
struct {
__u64 data;
__u16 length;
__u8 __pad[6];
} payload;
struct {
__u64 data;
__u16 length;
__u8 __pad[6];
} response;
} __attribute__((__packed__));
/**
* struct ssam_cdev_notifier_desc - Notifier descriptor.
* @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.
* @target_category: The event target category for which this notifier should
* receive events.
*
* Specifies the notifier that should be registered or unregistered,
* specifically with which priority and for which target category of events.
*/
struct ssam_cdev_notifier_desc {
__s32 priority;
__u8 target_category;
} __attribute__((__packed__));
/**
* struct ssam_cdev_event_desc - Event descriptor.
* @reg: Registry via which the event will be enabled/disabled.
* @reg.target_category: Target category for the event registry requests.
* @reg.target_id: Target ID for the event registry requests.
* @reg.cid_enable: Command ID for the event-enable request.
* @reg.cid_disable: Command ID for the event-disable request.
* @id: ID specifying the event.
* @id.target_category: Target category of the event source.
* @id.instance: Instance ID of the event source.
* @flags: Flags used for enabling the event.
*
* Specifies which event should be enabled/disabled and how to do that.
*/
struct ssam_cdev_event_desc {
struct {
__u8 target_category;
__u8 target_id;
__u8 cid_enable;
__u8 cid_disable;
} reg;
struct {
__u8 target_category;
__u8 instance;
} id;
__u8 flags;
} __attribute__((__packed__));
/**
* struct ssam_cdev_event - SSAM event sent by the EC.
* @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_cdev_event {
__u8 target_category;
__u8 target_id;
__u8 command_id;
__u8 instance_id;
__u16 length;
__u8 data[];
} __attribute__((__packed__));
#define SSAM_CDEV_REQUEST _IOWR(0xA5, 1, struct ssam_cdev_request)
#define SSAM_CDEV_NOTIF_REGISTER _IOW(0xA5, 2, struct ssam_cdev_notifier_desc)
#define SSAM_CDEV_NOTIF_UNREGISTER _IOW(0xA5, 3, struct ssam_cdev_notifier_desc)
#define SSAM_CDEV_EVENT_ENABLE _IOW(0xA5, 4, struct ssam_cdev_event_desc)
#define SSAM_CDEV_EVENT_DISABLE _IOW(0xA5, 5, struct ssam_cdev_event_desc)
#endif /* _LINUX_SURFACE_AGGREGATOR_CDEV_H */
