nrfConfigParamsPersistence.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2015 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 extern "C" {
00018 #include "pstorage.h"
00019 }
00020 
00021 #include "nrf_error.h"
00022 #include "ConfigParamsPersistence.h"
00023 
00024 /**
00025  * Nordic specific structure used to store params persistently.
00026  * It extends URIBeaconConfigService::Params_t with a persistence signature.
00027  */
00028 struct PersistentParams_t {
00029     URIBeaconConfigService::Params_t params;
00030     uint32_t                         persistenceSignature; /* This isn't really a parameter, but having the expected
00031                                                             * magic value in this field indicates persistence. */
00032 
00033     static const uint32_t MAGIC = 0x1BEAC000;              /* Magic that identifies persistence */
00034 };
00035 
00036 /**
00037  * The following is a module-local variable to hold configuration parameters for
00038  * short periods during flash access. This is necessary because the pstorage
00039  * APIs don't copy in the memory provided as data source. The memory cannot be
00040  * freed or reused by the application until this flash access is complete. The
00041  * load and store operations in this module initialize persistentParams and then
00042  * pass it on to the 'pstorage' APIs.
00043  */
00044 static PersistentParams_t persistentParams;
00045 
00046 static pstorage_handle_t pstorageHandle;
00047 
00048 /**
00049  * Dummy callback handler needed by Nordic's pstorage module. This is called
00050  * after every flash access.
00051  */
00052 static void pstorageNotificationCallback(pstorage_handle_t *p_handle,
00053                                          uint8_t            op_code,
00054                                          uint32_t           result,
00055                                          uint8_t           *p_data,
00056                                          uint32_t           data_len)
00057 {
00058     /* APP_ERROR_CHECK(result); */
00059 }
00060 
00061 /* Platform-specific implementation for persistence on the nRF5x. Based on the
00062  * pstorage module provided by the Nordic SDK. */
00063 bool loadURIBeaconConfigParams(URIBeaconConfigService::Params_t *paramsP)
00064 {
00065     static bool pstorageInitied = false;
00066     if (!pstorageInitied) {
00067         pstorage_init();
00068 
00069         static pstorage_module_param_t pstorageParams = {
00070             .cb          = pstorageNotificationCallback,
00071             .block_size  = sizeof(PersistentParams_t),
00072             .block_count = 1
00073         };
00074         pstorage_register(&pstorageParams, &pstorageHandle);
00075         pstorageInitied = true;
00076     }
00077 
00078     if ((pstorage_load(reinterpret_cast<uint8_t *>(&persistentParams), &pstorageHandle, sizeof(PersistentParams_t), 0) != NRF_SUCCESS) ||
00079         (persistentParams.persistenceSignature != PersistentParams_t::MAGIC)) {
00080         // On failure zero out and let the service reset to defaults
00081         memset(paramsP, 0, sizeof(URIBeaconConfigService::Params_t));
00082         return false;
00083     }
00084 
00085     memcpy(paramsP, &persistentParams.params, sizeof(URIBeaconConfigService::Params_t));
00086     return true;
00087 }
00088 
00089 /* Platform-specific implementation for persistence on the nRF5x. Based on the
00090  * pstorage module provided by the Nordic SDK. */
00091 void saveURIBeaconConfigParams(const URIBeaconConfigService::Params_t *paramsP)
00092 {
00093     memcpy(&persistentParams.params, paramsP, sizeof(URIBeaconConfigService::Params_t));
00094     if (persistentParams.persistenceSignature != PersistentParams_t::MAGIC) {
00095         persistentParams.persistenceSignature = PersistentParams_t::MAGIC;
00096         pstorage_store(&pstorageHandle,
00097                        reinterpret_cast<uint8_t *>(&persistentParams),
00098                        sizeof(PersistentParams_t),
00099                        0 /* offset */);
00100     } else {
00101         pstorage_update(&pstorageHandle,
00102                         reinterpret_cast<uint8_t *>(&persistentParams),
00103                         sizeof(PersistentParams_t),
00104                         0 /* offset */);
00105     }
00106 }