1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3  * Surface System Aggregator Module (SSAM) user-space EC interface.
4  *
5  * Definitions, structs, and IOCTLs for the /dev/surface/aggregator misc
6  * device. This device provides direct user-space access to the SSAM EC.
7  * Intended for debugging and development.
8  *
9  * Copyright (C) 2020-2021 Maximilian Luz <luzmaximilian@gmail.com>
10  */
11 
12 #ifndef _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H
13 #define _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H
14 
15 #include <linux/ioctl.h>
16 #include <linux/types.h>
17 
18 /**
19  * enum ssam_cdev_request_flags - Request flags for SSAM cdev request IOCTL.
20  *
21  * @SSAM_CDEV_REQUEST_HAS_RESPONSE:
22  *	Specifies that the request expects a response. If not set, the request
23  *	will be directly completed after its underlying packet has been
24  *	transmitted. If set, the request transport system waits for a response
25  *	of the request.
26  *
27  * @SSAM_CDEV_REQUEST_UNSEQUENCED:
28  *	Specifies that the request should be transmitted via an unsequenced
29  *	packet. If set, the request must not have a response, meaning that this
30  *	flag and the %SSAM_CDEV_REQUEST_HAS_RESPONSE flag are mutually
31  *	exclusive.
32  */
33 enum ssam_cdev_request_flags {
34 	SSAM_CDEV_REQUEST_HAS_RESPONSE = 0x01,
35 	SSAM_CDEV_REQUEST_UNSEQUENCED  = 0x02,
36 };
37 
38 /**
39  * struct ssam_cdev_request - Controller request IOCTL argument.
40  * @target_category: Target category of the SAM request.
41  * @target_id:       Target ID of the SAM request.
42  * @command_id:      Command ID of the SAM request.
43  * @instance_id:     Instance ID of the SAM request.
44  * @flags:           Request flags (see &enum ssam_cdev_request_flags).
45  * @status:          Request status (output).
46  * @payload:         Request payload (input data).
47  * @payload.data:    Pointer to request payload data.
48  * @payload.length:  Length of request payload data (in bytes).
49  * @response:        Request response (output data).
50  * @response.data:   Pointer to response buffer.
51  * @response.length: On input: Capacity of response buffer (in bytes).
52  *                   On output: Length of request response (number of bytes
53  *                   in the buffer that are actually used).
54  */
55 struct ssam_cdev_request {
56 	__u8 target_category;
57 	__u8 target_id;
58 	__u8 command_id;
59 	__u8 instance_id;
60 	__u16 flags;
61 	__s16 status;
62 
63 	struct {
64 		__u64 data;
65 		__u16 length;
66 		__u8 __pad[6];
67 	} payload;
68 
69 	struct {
70 		__u64 data;
71 		__u16 length;
72 		__u8 __pad[6];
73 	} response;
74 } __attribute__((__packed__));
75 
76 /**
77  * struct ssam_cdev_notifier_desc - Notifier descriptor.
78  * @priority:        Priority value determining the order in which notifier
79  *                   callbacks will be called. A higher value means higher
80  *                   priority, i.e. the associated callback will be executed
81  *                   earlier than other (lower priority) callbacks.
82  * @target_category: The event target category for which this notifier should
83  *                   receive events.
84  *
85  * Specifies the notifier that should be registered or unregistered,
86  * specifically with which priority and for which target category of events.
87  */
88 struct ssam_cdev_notifier_desc {
89 	__s32 priority;
90 	__u8 target_category;
91 } __attribute__((__packed__));
92 
93 /**
94  * struct ssam_cdev_event_desc - Event descriptor.
95  * @reg:                 Registry via which the event will be enabled/disabled.
96  * @reg.target_category: Target category for the event registry requests.
97  * @reg.target_id:       Target ID for the event registry requests.
98  * @reg.cid_enable:      Command ID for the event-enable request.
99  * @reg.cid_disable:     Command ID for the event-disable request.
100  * @id:                  ID specifying the event.
101  * @id.target_category:  Target category of the event source.
102  * @id.instance:         Instance ID of the event source.
103  * @flags:               Flags used for enabling the event.
104  *
105  * Specifies which event should be enabled/disabled and how to do that.
106  */
107 struct ssam_cdev_event_desc {
108 	struct {
109 		__u8 target_category;
110 		__u8 target_id;
111 		__u8 cid_enable;
112 		__u8 cid_disable;
113 	} reg;
114 
115 	struct {
116 		__u8 target_category;
117 		__u8 instance;
118 	} id;
119 
120 	__u8 flags;
121 } __attribute__((__packed__));
122 
123 /**
124  * struct ssam_cdev_event - SSAM event sent by the EC.
125  * @target_category: Target category of the event source. See &enum ssam_ssh_tc.
126  * @target_id:       Target ID of the event source.
127  * @command_id:      Command ID of the event.
128  * @instance_id:     Instance ID of the event source.
129  * @length:          Length of the event payload in bytes.
130  * @data:            Event payload data.
131  */
132 struct ssam_cdev_event {
133 	__u8 target_category;
134 	__u8 target_id;
135 	__u8 command_id;
136 	__u8 instance_id;
137 	__u16 length;
138 	__u8 data[];
139 } __attribute__((__packed__));
140 
141 #define SSAM_CDEV_REQUEST		_IOWR(0xA5, 1, struct ssam_cdev_request)
142 #define SSAM_CDEV_NOTIF_REGISTER	_IOW(0xA5, 2, struct ssam_cdev_notifier_desc)
143 #define SSAM_CDEV_NOTIF_UNREGISTER	_IOW(0xA5, 3, struct ssam_cdev_notifier_desc)
144 #define SSAM_CDEV_EVENT_ENABLE		_IOW(0xA5, 4, struct ssam_cdev_event_desc)
145 #define SSAM_CDEV_EVENT_DISABLE		_IOW(0xA5, 5, struct ssam_cdev_event_desc)
146 
147 #endif /* _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H */
148