1 /* 2 * Copyright (C) 2008 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 #ifndef ANDROID_INCLUDE_HARDWARE_HARDWARE_H 18 #define ANDROID_INCLUDE_HARDWARE_HARDWARE_H 19 20 #include <stdint.h> 21 #include <sys/cdefs.h> 22 23 #include <cutils/native_handle.h> 24 #include <system/graphics.h> 25 26 __BEGIN_DECLS 27 28 /* 29 * Value for the hw_module_t.tag field 30 */ 31 32 #define MAKE_TAG_CONSTANT(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) 33 34 #define HARDWARE_MODULE_TAG MAKE_TAG_CONSTANT('H', 'W', 'M', 'T') 35 #define HARDWARE_DEVICE_TAG MAKE_TAG_CONSTANT('H', 'W', 'D', 'T') 36 37 #define HARDWARE_MAKE_API_VERSION(maj,min) \ 38 ((((maj) & 0xff) << 8) | ((min) & 0xff)) 39 40 #define HARDWARE_MAKE_API_VERSION_2(maj,min,hdr) \ 41 ((((maj) & 0xff) << 24) | (((min) & 0xff) << 16) | ((hdr) & 0xffff)) 42 #define HARDWARE_API_VERSION_2_MAJ_MIN_MASK 0xffff0000 43 #define HARDWARE_API_VERSION_2_HEADER_MASK 0x0000ffff 44 45 46 /* 47 * The current HAL API version. 48 * 49 * All module implementations must set the hw_module_t.hal_api_version field 50 * to this value when declaring the module with HAL_MODULE_INFO_SYM. 51 * 52 * Note that previous implementations have always set this field to 0. 53 * Therefore, libhardware HAL API will always consider versions 0.0 and 1.0 54 * to be 100% binary compatible. 55 * 56 */ 57 #define HARDWARE_HAL_API_VERSION HARDWARE_MAKE_API_VERSION(1, 0) 58 59 /* 60 * Helper macros for module implementors. 61 * 62 * The derived modules should provide convenience macros for supported 63 * versions so that implementations can explicitly specify module/device 64 * versions at definition time. 65 * 66 * Use this macro to set the hw_module_t.module_api_version field. 67 */ 68 #define HARDWARE_MODULE_API_VERSION(maj,min) HARDWARE_MAKE_API_VERSION(maj,min) 69 #define HARDWARE_MODULE_API_VERSION_2(maj,min,hdr) HARDWARE_MAKE_API_VERSION_2(maj,min,hdr) 70 71 /* 72 * Use this macro to set the hw_device_t.version field 73 */ 74 #define HARDWARE_DEVICE_API_VERSION(maj,min) HARDWARE_MAKE_API_VERSION(maj,min) 75 #define HARDWARE_DEVICE_API_VERSION_2(maj,min,hdr) HARDWARE_MAKE_API_VERSION_2(maj,min,hdr) 76 77 struct hw_module_t; 78 struct hw_module_methods_t; 79 struct hw_device_t; 80 81 /** 82 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 83 * and the fields of this data structure must begin with hw_module_t 84 * followed by module specific information. 85 */ 86 typedef struct hw_module_t { 87 /** tag must be initialized to HARDWARE_MODULE_TAG */ 88 uint32_t tag; 89 90 /** 91 * The API version of the implemented module. The module owner is 92 * responsible for updating the version when a module interface has 93 * changed. 94 * 95 * The derived modules such as gralloc and audio own and manage this field. 96 * The module user must interpret the version field to decide whether or 97 * not to inter-operate with the supplied module implementation. 98 * For example, SurfaceFlinger is responsible for making sure that 99 * it knows how to manage different versions of the gralloc-module API, 100 * and AudioFlinger must know how to do the same for audio-module API. 101 * 102 * The module API version should include a major and a minor component. 103 * For example, version 1.0 could be represented as 0x0100. This format 104 * implies that versions 0x0100-0x01ff are all API-compatible. 105 * 106 * In the future, libhardware will expose a hw_get_module_version() 107 * (or equivalent) function that will take minimum/maximum supported 108 * versions as arguments and would be able to reject modules with 109 * versions outside of the supplied range. 110 */ 111 uint16_t module_api_version; 112 #define version_major module_api_version 113 /** 114 * version_major/version_minor defines are supplied here for temporary 115 * source code compatibility. They will be removed in the next version. 116 * ALL clients must convert to the new version format. 117 */ 118 119 /** 120 * The API version of the HAL module interface. This is meant to 121 * version the hw_module_t, hw_module_methods_t, and hw_device_t 122 * structures and definitions. 123 * 124 * The HAL interface owns this field. Module users/implementations 125 * must NOT rely on this value for version information. 126 * 127 * Presently, 0 is the only valid value. 128 */ 129 uint16_t hal_api_version; 130 #define version_minor hal_api_version 131 132 /** Identifier of module */ 133 const char *id; 134 135 /** Name of this module */ 136 const char *name; 137 138 /** Author/owner/implementor of the module */ 139 const char *author; 140 141 /** Modules methods */ 142 struct hw_module_methods_t* methods; 143 144 /** module's dso */ 145 void* dso; 146 147 /** padding to 128 bytes, reserved for future use */ 148 uint32_t reserved[32-7]; 149 150 } hw_module_t; 151 152 typedef struct hw_module_methods_t { 153 /** Open a specific device */ 154 int (*open)(const struct hw_module_t* module, const char* id, 155 struct hw_device_t** device); 156 157 } hw_module_methods_t; 158 159 /** 160 * Every device data structure must begin with hw_device_t 161 * followed by module specific public methods and attributes. 162 */ 163 typedef struct hw_device_t { 164 /** tag must be initialized to HARDWARE_DEVICE_TAG */ 165 uint32_t tag; 166 167 /** 168 * Version of the module-specific device API. This value is used by 169 * the derived-module user to manage different device implementations. 170 * 171 * The module user is responsible for checking the module_api_version 172 * and device version fields to ensure that the user is capable of 173 * communicating with the specific module implementation. 174 * 175 * One module can support multiple devices with different versions. This 176 * can be useful when a device interface changes in an incompatible way 177 * but it is still necessary to support older implementations at the same 178 * time. One such example is the Camera 2.0 API. 179 * 180 * This field is interpreted by the module user and is ignored by the 181 * HAL interface itself. 182 */ 183 uint32_t version; 184 185 /** reference to the module this device belongs to */ 186 struct hw_module_t* module; 187 188 /** padding reserved for future use */ 189 uint32_t reserved[12]; 190 191 /** Close this device */ 192 int (*close)(struct hw_device_t* device); 193 194 } hw_device_t; 195 196 /** 197 * Name of the hal_module_info 198 */ 199 #define HAL_MODULE_INFO_SYM HMI 200 201 /** 202 * Name of the hal_module_info as a string 203 */ 204 #define HAL_MODULE_INFO_SYM_AS_STR "HMI" 205 206 /** 207 * Get the module info associated with a module by id. 208 * 209 * @return: 0 == success, <0 == error and *module == NULL 210 */ 211 int hw_get_module(const char *id, const struct hw_module_t **module); 212 213 /** 214 * Get the module info associated with a module instance by class 'class_id' 215 * and instance 'inst'. 216 * 217 * Some modules types necessitate multiple instances. For example audio supports 218 * multiple concurrent interfaces and thus 'audio' is the module class 219 * and 'primary' or 'a2dp' are module interfaces. This implies that the files 220 * providing these modules would be named audio.primary.<variant>.so and 221 * audio.a2dp.<variant>.so 222 * 223 * @return: 0 == success, <0 == error and *module == NULL 224 */ 225 int hw_get_module_by_class(const char *class_id, const char *inst, 226 const struct hw_module_t **module); 227 228 __END_DECLS 229 230 #endif /* ANDROID_INCLUDE_HARDWARE_HARDWARE_H */ 231