hid/surface-hid/surface_hid_core.h

0001 /* SPDX-License-Identifier: GPL-2.0+ */
0002 /*
0003  * Common/core components for the Surface System Aggregator Module (SSAM) HID
0004  * transport driver. Provides support for integrated HID devices on Microsoft
0005  * Surface models.
0006  *
0007  * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
0008  */
0009
0010 #ifndef SURFACE_HID_CORE_H
0011 #define SURFACE_HID_CORE_H
0012
0013 #include <linux/hid.h>
0014 #include <linux/pm.h>
0015 #include <linux/types.h>
0016
0017 #include <linux/surface_aggregator/controller.h>
0018 #include <linux/surface_aggregator/device.h>
0019
0020 enum surface_hid_descriptor_entry {
0021     SURFACE_HID_DESC_HID    = 0,
0022     SURFACE_HID_DESC_REPORT = 1,
0023     SURFACE_HID_DESC_ATTRS  = 2,
0024 };
0025
0026 struct surface_hid_descriptor {
0027     __u8 desc_len;          /* = 9 */
0028     __u8 desc_type;         /* = HID_DT_HID */
0029     __le16 hid_version;
0030     __u8 country_code;
0031     __u8 num_descriptors;       /* = 1 */
0032
0033     __u8 report_desc_type;      /* = HID_DT_REPORT */
0034     __le16 report_desc_len;
0035 } __packed;
0036
0037 static_assert(sizeof(struct surface_hid_descriptor) == 9);
0038
0039 struct surface_hid_attributes {
0040     __le32 length;
0041     __le16 vendor;
0042     __le16 product;
0043     __le16 version;
0044     __u8 _unknown[22];
0045 } __packed;
0046
0047 static_assert(sizeof(struct surface_hid_attributes) == 32);
0048
0049 struct surface_hid_device;
0050
0051 struct surface_hid_device_ops {
0052     int (*get_descriptor)(struct surface_hid_device *shid, u8 entry, u8 *buf, size_t len);
0053     int (*output_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
0054     int (*get_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
0055     int (*set_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
0056 };
0057
0058 struct surface_hid_device {
0059     struct device *dev;
0060     struct ssam_controller *ctrl;
0061     struct ssam_device_uid uid;
0062
0063     struct surface_hid_descriptor hid_desc;
0064     struct surface_hid_attributes attrs;
0065
0066     struct ssam_event_notifier notif;
0067     struct hid_device *hid;
0068
0069     struct surface_hid_device_ops ops;
0070 };
0071
0072 int surface_hid_device_add(struct surface_hid_device *shid);
0073 void surface_hid_device_destroy(struct surface_hid_device *shid);
0074
0075 extern const struct dev_pm_ops surface_hid_pm_ops;
0076
0077 #endif /* SURFACE_HID_CORE_H */