drivers/hid/surface-hid/surface_hid_core.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Common/core components for the Surface System Aggregator Module (SSAM) HID
   4  * transport driver. Provides support for integrated HID devices on Microsoft
   5  * Surface models.
   6  *
   7  * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
   8  */
   9
  10 #ifndef SURFACE_HID_CORE_H
  11 #define SURFACE_HID_CORE_H
  12
  13 #include <linux/hid.h>
  14 #include <linux/pm.h>
  15 #include <linux/types.h>
  16
  17 #include <linux/surface_aggregator/controller.h>
  18 #include <linux/surface_aggregator/device.h>
  19
  20 enum surface_hid_descriptor_entry {
  21         SURFACE_HID_DESC_HID    = 0,
  22         SURFACE_HID_DESC_REPORT = 1,
  23         SURFACE_HID_DESC_ATTRS  = 2,
  24 };
  25
  26 struct surface_hid_descriptor {
  27         __u8 desc_len;                  /* = 9 */
  28         __u8 desc_type;                 /* = HID_DT_HID */
  29         __le16 hid_version;
  30         __u8 country_code;
  31         __u8 num_descriptors;           /* = 1 */
  32
  33         __u8 report_desc_type;          /* = HID_DT_REPORT */
  34         __le16 report_desc_len;
  35 } __packed;
  36
  37 static_assert(sizeof(struct surface_hid_descriptor) == 9);
  38
  39 struct surface_hid_attributes {
  40         __le32 length;
  41         __le16 vendor;
  42         __le16 product;
  43         __le16 version;
  44         __u8 _unknown[22];
  45 } __packed;
  46
  47 static_assert(sizeof(struct surface_hid_attributes) == 32);
  48
  49 struct surface_hid_device;
  50
  51 struct surface_hid_device_ops {
  52         int (*get_descriptor)(struct surface_hid_device *shid, u8 entry, u8 *buf, size_t len);
  53         int (*output_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
  54         int (*get_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
  55         int (*set_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len);
  56 };
  57
  58 struct surface_hid_device {
  59         struct device *dev;
  60         struct ssam_controller *ctrl;
  61         struct ssam_device_uid uid;
  62
  63         struct surface_hid_descriptor hid_desc;
  64         struct surface_hid_attributes attrs;
  65
  66         struct ssam_event_notifier notif;
  67         struct hid_device *hid;
  68
  69         struct surface_hid_device_ops ops;
  70 };
  71
  72 int surface_hid_device_add(struct surface_hid_device *shid);
  73 void surface_hid_device_destroy(struct surface_hid_device *shid);
  74
  75 extern const struct dev_pm_ops surface_hid_pm_ops;
  76
  77 #endif /* SURFACE_HID_CORE_H */