include/uapi/linux/surface_aggregator/cdev.h

   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 */