1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17
18 #ifndef ANDROID_LOCAL_TIME_HAL_INTERFACE_H
19 #define ANDROID_LOCAL_TIME_HAL_INTERFACE_H
20
21 #include <stdint.h>
22
23 #include <hardware/hardware.h>
24
25 __BEGIN_DECLS
26
27 /**
28 * The id of this module
29 */
30 #define LOCAL_TIME_HARDWARE_MODULE_ID "local_time"
31
32 /**
33 * Name of the local time devices to open
34 */
35 #define LOCAL_TIME_HARDWARE_INTERFACE "local_time_hw_if"
36
37 /**********************************************************************/
38
39 /**
40 * A structure used to collect low level sync data in a lab environment. Most
41 * HAL implementations will never need this structure.
42 */
43 struct local_time_debug_event {
44 int64_t local_timesync_event_id;
45 int64_t local_time;
46 };
47
48 /**
49 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
50 * and the fields of this data structure must begin with hw_module_t
51 * followed by module specific information.
52 */
53 struct local_time_module {
54 struct hw_module_t common;
55 };
56
57 struct local_time_hw_device {
58 /**
59 * Common methods of the local time hardware device. This *must* be the first member of
60 * local_time_hw_device as users of this structure will cast a hw_device_t to
61 * local_time_hw_device pointer in contexts where it's known the hw_device_t references a
62 * local_time_hw_device.
63 */
64 struct hw_device_t common;
65
66 /**
67 *
68 * Returns the current value of the system wide local time counter
69 */
70 int64_t (*get_local_time)(struct local_time_hw_device* dev);
71
72 /**
73 *
74 * Returns the nominal frequency (in hertz) of the system wide local time
75 * counter
76 */
77 uint64_t (*get_local_freq)(struct local_time_hw_device* dev);
78
79 /**
80 *
81 * Sets the HW slew rate of oscillator which drives the system wide local
82 * time counter. On success, platforms should return 0. Platforms which
83 * do not support HW slew should leave this method set to NULL.
84 *
85 * Valid values for rate range from MIN_INT16 to MAX_INT16. Platform
86 * implementations should attempt map this range linearly to the min/max
87 * slew rate of their hardware.
88 */
89 int (*set_local_slew)(struct local_time_hw_device* dev, int16_t rate);
90
91 /**
92 *
93 * A method used to collect low level sync data in a lab environments.
94 * Most HAL implementations will simply set this member to NULL, or return
95 * -EINVAL to indicate that this functionality is not supported.
96 * Production HALs should never support this method.
97 */
98 int (*get_debug_log)(struct local_time_hw_device* dev,
99 struct local_time_debug_event* records,
100 int max_records);
101 };
102
103 typedef struct local_time_hw_device local_time_hw_device_t;
104
105 /** convenience API for opening and closing a supported device */
106
local_time_hw_device_open(const struct hw_module_t * module,struct local_time_hw_device ** device)107 static inline int local_time_hw_device_open(
108 const struct hw_module_t* module,
109 struct local_time_hw_device** device)
110 {
111 return module->methods->open(module, LOCAL_TIME_HARDWARE_INTERFACE,
112 TO_HW_DEVICE_T_OPEN(device));
113 }
114
local_time_hw_device_close(struct local_time_hw_device * device)115 static inline int local_time_hw_device_close(struct local_time_hw_device* device)
116 {
117 return device->common.close(&device->common);
118 }
119
120
121 __END_DECLS
122
123 #endif // ANDROID_LOCAL_TIME_INTERFACE_H
124