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1/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2/*
3 * Surface DTX (clipboard detachment system driver) user-space interface.
4 *
5 * Definitions, structs, and IOCTLs for the /dev/surface/dtx misc device. This
6 * device allows user-space to control the clipboard detachment process on
7 * Surface Book series devices.
8 *
9 * Copyright (C) 2020-2021 Maximilian Luz <luzmaximilian@gmail.com>
10 */
11
12#ifndef _LINUX_SURFACE_AGGREGATOR_DTX_H
13#define _LINUX_SURFACE_AGGREGATOR_DTX_H
14
15#include <linux/ioctl.h>
16#include <linux/types.h>
17
18/* Status/error categories */
19#define SDTX_CATEGORY_STATUS 0x0000
20#define SDTX_CATEGORY_RUNTIME_ERROR 0x1000
21#define SDTX_CATEGORY_HARDWARE_ERROR 0x2000
22#define SDTX_CATEGORY_UNKNOWN 0xf000
23
24#define SDTX_CATEGORY_MASK 0xf000
25#define SDTX_CATEGORY(value) ((value) & SDTX_CATEGORY_MASK)
26
27#define SDTX_STATUS(code) ((code) | SDTX_CATEGORY_STATUS)
28#define SDTX_ERR_RT(code) ((code) | SDTX_CATEGORY_RUNTIME_ERROR)
29#define SDTX_ERR_HW(code) ((code) | SDTX_CATEGORY_HARDWARE_ERROR)
30#define SDTX_UNKNOWN(code) ((code) | SDTX_CATEGORY_UNKNOWN)
31
32#define SDTX_SUCCESS(value) (SDTX_CATEGORY(value) == SDTX_CATEGORY_STATUS)
33
34/* Latch status values */
35#define SDTX_LATCH_CLOSED SDTX_STATUS(0x00)
36#define SDTX_LATCH_OPENED SDTX_STATUS(0x01)
37
38/* Base state values */
39#define SDTX_BASE_DETACHED SDTX_STATUS(0x00)
40#define SDTX_BASE_ATTACHED SDTX_STATUS(0x01)
41
42/* Runtime errors (non-critical) */
43#define SDTX_DETACH_NOT_FEASIBLE SDTX_ERR_RT(0x01)
44#define SDTX_DETACH_TIMEDOUT SDTX_ERR_RT(0x02)
45
46/* Hardware errors (critical) */
47#define SDTX_ERR_FAILED_TO_OPEN SDTX_ERR_HW(0x01)
48#define SDTX_ERR_FAILED_TO_REMAIN_OPEN SDTX_ERR_HW(0x02)
49#define SDTX_ERR_FAILED_TO_CLOSE SDTX_ERR_HW(0x03)
50
51/* Base types */
52#define SDTX_DEVICE_TYPE_HID 0x0100
53#define SDTX_DEVICE_TYPE_SSH 0x0200
54
55#define SDTX_DEVICE_TYPE_MASK 0x0f00
56#define SDTX_DEVICE_TYPE(value) ((value) & SDTX_DEVICE_TYPE_MASK)
57
58#define SDTX_BASE_TYPE_HID(id) ((id) | SDTX_DEVICE_TYPE_HID)
59#define SDTX_BASE_TYPE_SSH(id) ((id) | SDTX_DEVICE_TYPE_SSH)
60
61/**
62 * enum sdtx_device_mode - Mode describing how (and if) the clipboard is
63 * attached to the base of the device.
64 * @SDTX_DEVICE_MODE_TABLET: The clipboard is detached from the base and the
65 * device operates as tablet.
66 * @SDTX_DEVICE_MODE_LAPTOP: The clipboard is attached normally to the base
67 * and the device operates as laptop.
68 * @SDTX_DEVICE_MODE_STUDIO: The clipboard is attached to the base in reverse.
69 * The device operates as tablet with keyboard and
70 * touchpad deactivated, however, the base battery
71 * and, if present in the specific device model, dGPU
72 * are available to the system.
73 */
74enum sdtx_device_mode {
75 SDTX_DEVICE_MODE_TABLET = 0x00,
76 SDTX_DEVICE_MODE_LAPTOP = 0x01,
77 SDTX_DEVICE_MODE_STUDIO = 0x02,
78};
79
80/**
81 * struct sdtx_event - Event provided by reading from the DTX device file.
82 * @length: Length of the event payload, in bytes.
83 * @code: Event code, detailing what type of event this is.
84 * @data: Payload of the event, containing @length bytes.
85 *
86 * See &enum sdtx_event_code for currently valid event codes.
87 */
88struct sdtx_event {
89 __u16 length;
90 __u16 code;
91 __u8 data[];
92} __attribute__((__packed__));
93
94/**
95 * enum sdtx_event_code - Code describing the type of an event.
96 * @SDTX_EVENT_REQUEST: Detachment request event type.
97 * @SDTX_EVENT_CANCEL: Cancel detachment process event type.
98 * @SDTX_EVENT_BASE_CONNECTION: Base/clipboard connection change event type.
99 * @SDTX_EVENT_LATCH_STATUS: Latch status change event type.
100 * @SDTX_EVENT_DEVICE_MODE: Device mode change event type.
101 *
102 * Used in &struct sdtx_event to describe the type of the event. Further event
103 * codes are reserved for future use. Any event parser should be able to
104 * gracefully handle unknown events, i.e. by simply skipping them.
105 *
106 * Consult the DTX user-space interface documentation for details regarding
107 * the individual event types.
108 */
109enum sdtx_event_code {
110 SDTX_EVENT_REQUEST = 1,
111 SDTX_EVENT_CANCEL = 2,
112 SDTX_EVENT_BASE_CONNECTION = 3,
113 SDTX_EVENT_LATCH_STATUS = 4,
114 SDTX_EVENT_DEVICE_MODE = 5,
115};
116
117/**
118 * struct sdtx_base_info - Describes if and what type of base is connected.
119 * @state: The state of the connection. Valid values are %SDTX_BASE_DETACHED,
120 * %SDTX_BASE_ATTACHED, and %SDTX_DETACH_NOT_FEASIBLE (in case a base
121 * is attached but low clipboard battery prevents detachment). Other
122 * values are currently reserved.
123 * @base_id: The type of base connected. Zero if no base is connected.
124 */
125struct sdtx_base_info {
126 __u16 state;
127 __u16 base_id;
128} __attribute__((__packed__));
129
130/* IOCTLs */
131#define SDTX_IOCTL_EVENTS_ENABLE _IO(0xa5, 0x21)
132#define SDTX_IOCTL_EVENTS_DISABLE _IO(0xa5, 0x22)
133
134#define SDTX_IOCTL_LATCH_LOCK _IO(0xa5, 0x23)
135#define SDTX_IOCTL_LATCH_UNLOCK _IO(0xa5, 0x24)
136
137#define SDTX_IOCTL_LATCH_REQUEST _IO(0xa5, 0x25)
138#define SDTX_IOCTL_LATCH_CONFIRM _IO(0xa5, 0x26)
139#define SDTX_IOCTL_LATCH_HEARTBEAT _IO(0xa5, 0x27)
140#define SDTX_IOCTL_LATCH_CANCEL _IO(0xa5, 0x28)
141
142#define SDTX_IOCTL_GET_BASE_INFO _IOR(0xa5, 0x29, struct sdtx_base_info)
143#define SDTX_IOCTL_GET_DEVICE_MODE _IOR(0xa5, 0x2a, __u16)
144#define SDTX_IOCTL_GET_LATCH_STATUS _IOR(0xa5, 0x2b, __u16)
145
146#endif /* _LINUX_SURFACE_AGGREGATOR_DTX_H */