1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright 2024 Intel Corporation */
3
4#include <linux/bits.h>
5
6#ifndef _HID_OVER_I2C_H_
7#define _HID_OVER_I2C_H_
8
9#define HIDI2C_REG_LEN sizeof(__le16)
10
11/* Input report type definition in HIDI2C protocol */
12enum hidi2c_report_type {
13 HIDI2C_RESERVED = 0,
14 HIDI2C_INPUT,
15 HIDI2C_OUTPUT,
16 HIDI2C_FEATURE,
17};
18
19/* Power state type definition in HIDI2C protocol */
20enum hidi2c_power_state {
21 HIDI2C_ON,
22 HIDI2C_SLEEP,
23};
24
25/* Opcode type definition in HIDI2C protocol */
26enum hidi2c_opcode {
27 HIDI2C_RESET = 1,
28 HIDI2C_GET_REPORT,
29 HIDI2C_SET_REPORT,
30 HIDI2C_GET_IDLE,
31 HIDI2C_SET_IDLE,
32 HIDI2C_GET_PROTOCOL,
33 HIDI2C_SET_PROTOCOL,
34 HIDI2C_SET_POWER,
35};
36
37/**
38 * struct hidi2c_report_packet - Report packet definition in HIDI2C protocol
39 * @len: data field length
40 * @data: HIDI2C report packet data
41 */
42struct hidi2c_report_packet {
43 __le16 len;
44 u8 data[];
45} __packed;
46
47#define HIDI2C_LENGTH_LEN sizeof(__le16)
48
49#define HIDI2C_PACKET_LEN(data_len) ((data_len) + HIDI2C_LENGTH_LEN)
50#define HIDI2C_DATA_LEN(pkt_len) ((pkt_len) - HIDI2C_LENGTH_LEN)
51
52#define HIDI2C_CMD_MAX_RI 0x0F
53
54/**
55 * HIDI2C command data packet - Command packet definition in HIDI2C protocol
56 * @report_id: [0:3] report id (<15) for features or output reports
57 * @report_type: [4:5] indicate report type, reference to hidi2c_report_type
58 * @reserved0: [6:7] reserved bits
59 * @opcode: [8:11] command operation code, reference to hidi2c_opcode
60 * @reserved1: [12:15] reserved bits
61 * @report_id_optional: [23:16] appended 3rd byte.
62 * If the report_id in the low byte is set to the
63 * sentinel value (HIDI2C_CMD_MAX_RI), then this
64 * optional third byte represents the report id (>=15)
65 * Otherwise, not this 3rd byte.
66 */
67
68#define HIDI2C_CMD_LEN sizeof(__le16)
69#define HIDI2C_CMD_LEN_OPT (sizeof(__le16) + 1)
70#define HIDI2C_CMD_REPORT_ID GENMASK(3, 0)
71#define HIDI2C_CMD_REPORT_TYPE GENMASK(5, 4)
72#define HIDI2C_CMD_OPCODE GENMASK(11, 8)
73#define HIDI2C_CMD_OPCODE GENMASK(11, 8)
74#define HIDI2C_CMD_3RD_BYTE GENMASK(23, 16)
75
76#define HIDI2C_HID_DESC_BCDVERSION 0x100
77
78/**
79 * struct hidi2c_dev_descriptor - HIDI2C device descriptor definition
80 * @dev_desc_len: The length of the complete device descriptor, fixed to 0x1E (30).
81 * @bcd_ver: The version number of the HIDI2C protocol supported.
82 * In binary coded decimal (BCD) format.
83 * @report_desc_len: The length of the report descriptor
84 * @report_desc_reg: The register address to retrieve report descriptor
85 * @input_reg: the register address to retrieve input report
86 * @max_input_len: The length of the largest possible HID input (or feature) report
87 * @output_reg: the register address to send output report
88 * @max_output_len: The length of the largest output (or feature) report
89 * @cmd_reg: the register address to send command
90 * @data_reg: the register address to send command data
91 * @vendor_id: Device manufacturers vendor ID
92 * @product_id: Device unique model/product ID
93 * @version_id: Device’s unique version
94 * @reserved0: Reserved and should be 0
95 * @reserved1: Reserved and should be 0
96 */
97struct hidi2c_dev_descriptor {
98 __le16 dev_desc_len;
99 __le16 bcd_ver;
100 __le16 report_desc_len;
101 __le16 report_desc_reg;
102 __le16 input_reg;
103 __le16 max_input_len;
104 __le16 output_reg;
105 __le16 max_output_len;
106 __le16 cmd_reg;
107 __le16 data_reg;
108 __le16 vendor_id;
109 __le16 product_id;
110 __le16 version_id;
111 __le16 reserved0;
112 __le16 reserved1;
113} __packed;
114
115#define HIDI2C_DEV_DESC_LEN sizeof(struct hidi2c_dev_descriptor)
116
117#endif /* _HID_OVER_I2C_H_ */
118

source code of linux/include/linux/hid-over-i2c.h