src/main/drivers/persistent.c

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * An implementation of persistent data storage utilizing RTC backup data register.
  23  * Retains values written across software resets and boot loader activities.
  24  */
  25
  26 #include <stdint.h>
  27 #include "platform.h"
  28
  29 #include "drivers/persistent.h"
  30 #include "drivers/system.h"
  31
  32 #define PERSISTENT_OBJECT_MAGIC_VALUE (('B' << 24)|('e' << 16)|('f' << 8)|('1' << 0))
  33
  34 #ifdef USE_HAL_DRIVER
  35
  36 uint32_t persistentObjectRead(persistentObjectId_e id)
  37 {
  38     RTC_HandleTypeDef rtcHandle = { .Instance = RTC };
  39
  40     uint32_t value = HAL_RTCEx_BKUPRead(&rtcHandle, id);
  41
  42     return value;
  43 }
  44
  45 void persistentObjectWrite(persistentObjectId_e id, uint32_t value)
  46 {
  47     RTC_HandleTypeDef rtcHandle = { .Instance = RTC };
  48
  49     HAL_RTCEx_BKUPWrite(&rtcHandle, id, value);
  50
  51 #ifdef USE_SPRACING_PERSISTENT_RTC_WORKAROUND
  52     // Also write the persistent location used by the bootloader to support DFU etc.
  53     if (id == PERSISTENT_OBJECT_RESET_REASON) {
  54         // SPRACING firmware sometimes enters DFU mode when MSC mode is requested
  55         if (value == RESET_MSC_REQUEST) {
  56             value = RESET_NONE;
  57         }
  58         HAL_RTCEx_BKUPWrite(&rtcHandle, PERSISTENT_OBJECT_RESET_REASON_FWONLY, value);
  59     }
  60 #endif
  61 }
  62
  63 void persistentObjectRTCEnable(void)
  64 {
  65 #if !defined(STM32G4)
  66     // G4 library V1.0.0 __HAL_RTC_WRITEPROTECTION_ENABLE/DISABLE macro does not use handle parameter
  67     RTC_HandleTypeDef rtcHandle = { .Instance = RTC };
  68 #endif
  69
  70 #if !defined(STM32H7)
  71     __HAL_RCC_PWR_CLK_ENABLE(); // Enable Access to PWR
  72 #endif
  73
  74     HAL_PWR_EnableBkUpAccess(); // Disable backup domain protection
  75
  76 #if defined(STM32G4)
  77     /* Enable RTC APB clock  */
  78     __HAL_RCC_RTCAPB_CLK_ENABLE();
  79
  80     /* Peripheral clock enable */
  81     __HAL_RCC_RTC_ENABLE();
  82
  83 #else // !STM32G4, F7 and H7 case
  84
  85 #if defined(__HAL_RCC_RTC_CLK_ENABLE)
  86     // For those MCUs with RTCAPBEN bit in RCC clock enable register, turn it on.
  87     __HAL_RCC_RTC_CLK_ENABLE(); // Enable RTC module
  88 #endif
  89
  90 #endif // STM32G4
  91
  92     // We don't need a clock source for RTC itself. Skip it.
  93
  94     __HAL_RTC_WRITEPROTECTION_ENABLE(&rtcHandle);  // Reset sequence
  95     __HAL_RTC_WRITEPROTECTION_DISABLE(&rtcHandle); // Apply sequence
  96 }
  97
  98 #else
  99 uint32_t persistentObjectRead(persistentObjectId_e id)
 100 {
 101     uint32_t value = RTC_ReadBackupRegister(id);
 102
 103     return value;
 104 }
 105
 106 void persistentObjectWrite(persistentObjectId_e id, uint32_t value)
 107 {
 108     RTC_WriteBackupRegister(id, value);
 109 }
 110
 111 void persistentObjectRTCEnable(void)
 112 {
 113     RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE); // Enable Access to PWR
 114     PWR_BackupAccessCmd(ENABLE); // Disable backup domain protection
 115
 116     // We don't need a clock source for RTC itself. Skip it.
 117
 118     RTC_WriteProtectionCmd(ENABLE);  // Reset sequence
 119     RTC_WriteProtectionCmd(DISABLE); // Apply sequence
 120 }
 121 #endif
 122
 123 void persistentObjectInit(void)
 124 {
 125     // Configure and enable RTC for backup register access
 126
 127     persistentObjectRTCEnable();
 128
 129     // XXX Magic value checking may be sufficient
 130
 131     uint32_t wasSoftReset;
 132
 133 #ifdef STM32H7
 134     wasSoftReset = RCC->RSR & RCC_RSR_SFTRSTF;
 135 #else
 136     wasSoftReset = RCC->CSR & RCC_CSR_SFTRSTF;
 137 #endif
 138
 139     if (!wasSoftReset || (persistentObjectRead(PERSISTENT_OBJECT_MAGIC) != PERSISTENT_OBJECT_MAGIC_VALUE)) {
 140         for (int i = 1; i < PERSISTENT_OBJECT_COUNT; i++) {
 141             persistentObjectWrite(i, 0);
 142         }
 143         persistentObjectWrite(PERSISTENT_OBJECT_MAGIC, PERSISTENT_OBJECT_MAGIC_VALUE);
 144     }
 145 }