/************************************************************************************//** * \file Source/ARMCM4_STM32F3/can.c * \brief Bootloader CAN communication interface source file. * \ingroup Target_ARMCM4_STM32F3 * \internal *---------------------------------------------------------------------------------------- * C O P Y R I G H T *---------------------------------------------------------------------------------------- * Copyright (c) 2016 by Feaser http://www.feaser.com All rights reserved * *---------------------------------------------------------------------------------------- * L I C E N S E *---------------------------------------------------------------------------------------- * This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or * modify it under the terms of the GNU General Public License as published by the Free * Software Foundation, either version 3 of the License, or (at your option) any later * version. * * OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR * PURPOSE. See the GNU General Public License for more details. * * You have received a copy of the GNU General Public License along with OpenBLT. It * should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy. * * \endinternal ****************************************************************************************/ /**************************************************************************************** * Include files ****************************************************************************************/ #include "boot.h" /* bootloader generic header */ #include "stm32f3xx.h" /* STM32 CPU and HAL header */ #include "stm32f3xx_ll_rcc.h" /* STM32 LL RCC header */ #if (BOOT_COM_CAN_ENABLE > 0) /**************************************************************************************** * Macro definitions ****************************************************************************************/ /** \brief Timeout for transmitting a CAN message in milliseconds. */ #define CAN_MSG_TX_TIMEOUT_MS (50u) /**************************************************************************************** * Type definitions ****************************************************************************************/ /** \brief Structure type for grouping CAN bus timing related information. */ typedef struct t_can_bus_timing { blt_int8u tseg1; /**< CAN time segment 1 */ blt_int8u tseg2; /**< CAN time segment 2 */ } tCanBusTiming; /**************************************************************************************** * Local constant declarations ****************************************************************************************/ /** \brief CAN bittiming table for dynamically calculating the bittiming settings. * \details According to the CAN protocol 1 bit-time can be made up of between 8..25 * time quanta (TQ). The total TQ in a bit is SYNC + TSEG1 + TSEG2 with SYNC * always being 1. The sample point is (SYNC + TSEG1) / (SYNC + TSEG1 + SEG2) * * 100%. This array contains possible and valid time quanta configurations with * a sample point between 68..78%. */ static const tCanBusTiming canTiming[] = { /* TQ | TSEG1 | TSEG2 | SP */ /* ------------------------- */ { 5, 2 }, /* 8 | 5 | 2 | 75% */ { 6, 2 }, /* 9 | 6 | 2 | 78% */ { 6, 3 }, /* 10 | 6 | 3 | 70% */ { 7, 3 }, /* 11 | 7 | 3 | 73% */ { 8, 3 }, /* 12 | 8 | 3 | 75% */ { 9, 3 }, /* 13 | 9 | 3 | 77% */ { 9, 4 }, /* 14 | 9 | 4 | 71% */ { 10, 4 }, /* 15 | 10 | 4 | 73% */ { 11, 4 }, /* 16 | 11 | 4 | 75% */ { 12, 4 }, /* 17 | 12 | 4 | 76% */ { 12, 5 }, /* 18 | 12 | 5 | 72% */ { 13, 5 }, /* 19 | 13 | 5 | 74% */ { 14, 5 }, /* 20 | 14 | 5 | 75% */ { 15, 5 }, /* 21 | 15 | 5 | 76% */ { 15, 6 }, /* 22 | 15 | 6 | 73% */ { 16, 6 }, /* 23 | 16 | 6 | 74% */ { 16, 7 }, /* 24 | 16 | 7 | 71% */ { 16, 8 } /* 25 | 16 | 8 | 68% */ }; /**************************************************************************************** * Local data declarations ****************************************************************************************/ /** \brief CAN handle to be used in API calls. */ static CAN_HandleTypeDef canHandle; /** \brief Message buffer for transmitting CAN messages. */ static CanTxMsgTypeDef canTxMessage; /** \brief Message buffer for receiving CAN messages. */ static CanRxMsgTypeDef canRxMessage; /************************************************************************************//** ** \brief Search algorithm to match the desired baudrate to a possible bus ** timing configuration. ** \param baud The desired baudrate in kbps. Valid values are 10..1000. ** \param prescaler Pointer to where the value for the prescaler will be stored. ** \param tseg1 Pointer to where the value for TSEG2 will be stored. ** \param tseg2 Pointer to where the value for TSEG2 will be stored. ** \return BLT_TRUE if the CAN bustiming register values were found, BLT_FALSE ** otherwise. ** ****************************************************************************************/ static blt_bool CanGetSpeedConfig(blt_int16u baud, blt_int16u *prescaler, blt_int8u *tseg1, blt_int8u *tseg2) { blt_int8u cnt; blt_int32u canClockFreqkHz; LL_RCC_ClocksTypeDef rccClocks; /* read clock frequencies */ LL_RCC_GetSystemClocksFreq(&rccClocks); /* store CAN peripheral clock speed in kHz */ canClockFreqkHz = rccClocks.PCLK1_Frequency / 1000u; /* loop through all possible time quanta configurations to find a match */ for (cnt=0; cnt < sizeof(canTiming)/sizeof(canTiming[0]); cnt++) { if ((canClockFreqkHz % (baud*(canTiming[cnt].tseg1+canTiming[cnt].tseg2+1))) == 0) { /* compute the prescaler that goes with this TQ configuration */ *prescaler = canClockFreqkHz/(baud*(canTiming[cnt].tseg1+canTiming[cnt].tseg2+1)); /* make sure the prescaler is valid */ if ((*prescaler > 0) && (*prescaler <= 1024)) { /* store the bustiming configuration */ *tseg1 = canTiming[cnt].tseg1; *tseg2 = canTiming[cnt].tseg2; /* found a good bus timing configuration */ return BLT_TRUE; } } } /* could not find a good bus timing configuration */ return BLT_FALSE; } /*** end of CanGetSpeedConfig ***/ /************************************************************************************//** ** \brief Initializes the CAN controller and synchronizes it to the CAN bus. ** \return none. ** ****************************************************************************************/ void CanInit(void) { blt_int16u prescaler = 0; blt_int8u tseg1 = 0, tseg2 = 0; CAN_FilterConfTypeDef filterConfig; blt_int32u rxMsgId = BOOT_COM_CAN_RX_MSG_ID; blt_int32u rxFilterId, rxFilterMask; /* the current implementation supports CAN1. throw an assertion error in case a * different CAN channel is configured. */ ASSERT_CT(BOOT_COM_CAN_CHANNEL_INDEX == 0); /* obtain bittiming configuration information. */ if (CanGetSpeedConfig(BOOT_COM_CAN_BAUDRATE/1000, &prescaler, &tseg1, &tseg2) == BLT_FALSE) { /* Incorrect configuration. The specified baudrate is not supported for the given * clock configuration. Verify the following settings in blt_conf.h: * - BOOT_COM_CAN_BAUDRATE * - BOOT_CPU_XTAL_SPEED_KHZ * - BOOT_CPU_SYSTEM_SPEED_KHZ */ ASSERT_RT(BLT_FALSE); } /* set the CAN controller configuration. */ canHandle.Instance = CAN; canHandle.pTxMsg = &canTxMessage; canHandle.pRxMsg = &canRxMessage; canHandle.Init.TTCM = DISABLE; canHandle.Init.ABOM = DISABLE; canHandle.Init.AWUM = DISABLE; canHandle.Init.NART = DISABLE; canHandle.Init.RFLM = DISABLE; canHandle.Init.TXFP = DISABLE; canHandle.Init.Mode = CAN_MODE_NORMAL; canHandle.Init.SJW = CAN_SJW_1TQ; canHandle.Init.BS1 = ((blt_int32u)tseg1 - 1) << CAN_BTR_TS1_Pos; canHandle.Init.BS2 = ((blt_int32u)tseg2 - 1) << CAN_BTR_TS2_Pos; canHandle.Init.Prescaler = prescaler; /* initialize the CAN controller. this only fails if the CAN controller hardware is * faulty. no need to evaluate the return value as there is nothing we can do about * a faulty CAN controller. */ (void)HAL_CAN_Init(&canHandle); /* determine the reception filter mask and id values such that it only leaves one * CAN identifier through (BOOT_COM_CAN_RX_MSG_ID). */ if ((rxMsgId & 0x80000000) == 0) { rxFilterId = rxMsgId << CAN_RI0R_STID_Pos; rxFilterMask = (CAN_RI0R_STID_Msk) | CAN_RI0R_IDE; } else { /* negate the ID-type bit */ rxMsgId &= ~0x80000000; rxFilterId = (rxMsgId << CAN_RI0R_EXID_Pos) | CAN_RI0R_IDE; rxFilterMask = (CAN_RI0R_EXID_Msk) | CAN_RI0R_IDE; } /* configure the reception filter. note that the implementation of this function * always returns HAL_OK, so no need to evaluate the return value. */ filterConfig.FilterNumber = 0; filterConfig.FilterMode = CAN_FILTERMODE_IDMASK; filterConfig.FilterScale = CAN_FILTERSCALE_32BIT; filterConfig.FilterIdHigh = (rxFilterId >> 16) & 0x0000FFFFu; filterConfig.FilterIdLow = rxFilterId & 0x0000FFFFu; filterConfig.FilterMaskIdHigh = (rxFilterMask >> 16) & 0x0000FFFFu; filterConfig.FilterMaskIdLow = rxFilterMask & 0x0000FFFFu; filterConfig.FilterFIFOAssignment = 0; filterConfig.FilterActivation = ENABLE; /* the bank number is don't care for STM32F3 devices as it only supports one CAN * controller. */ filterConfig.BankNumber = 14; (void)HAL_CAN_ConfigFilter(&canHandle, &filterConfig); } /*** end of CanInit ***/ /************************************************************************************//** ** \brief Transmits a packet formatted for the communication interface. ** \param data Pointer to byte array with data that it to be transmitted. ** \param len Number of bytes that are to be transmitted. ** \return none. ** ****************************************************************************************/ void CanTransmitPacket(blt_int8u *data, blt_int8u len) { blt_int8u byteIdx; blt_int32u txMsgId = BOOT_COM_CAN_TX_MSG_ID; /* configure the message that should be transmitted. */ if ((txMsgId & 0x80000000) == 0) { /* set the 11-bit CAN identifier. */ canHandle.pTxMsg->StdId = txMsgId; canHandle.pTxMsg->IDE = CAN_ID_STD; } else { /* negate the ID-type bit */ txMsgId &= ~0x80000000; /* set the 29-bit CAN identifier. */ canHandle.pTxMsg->ExtId = txMsgId; canHandle.pTxMsg->IDE = CAN_ID_EXT; } canHandle.pTxMsg->RTR = CAN_RTR_DATA; canHandle.pTxMsg->DLC = len; /* copy the message data. */ for (byteIdx = 0; byteIdx < len; byteIdx++) { canHandle.pTxMsg->Data[byteIdx] = data[byteIdx]; } /* submit the message for transmission. no need to check the return value. if the * response cannot be transmitted, then the receiving node will detect a timeout. */ (void)HAL_CAN_Transmit(&canHandle, CAN_MSG_TX_TIMEOUT_MS); } /*** end of CanTransmitPacket ***/ /************************************************************************************//** ** \brief Receives a communication interface packet if one is present. ** \param data Pointer to byte array where the data is to be stored. ** \param len Pointer where the length of the packet is to be stored. ** \return BLT_TRUE is a packet was received, BLT_FALSE otherwise. ** ****************************************************************************************/ blt_bool CanReceivePacket(blt_int8u *data, blt_int8u *len) { blt_int32u rxMsgId = BOOT_COM_CAN_RX_MSG_ID; blt_bool result = BLT_FALSE; blt_bool packetIdMatches = BLT_FALSE; blt_int8u byteIdx; /* poll for received CAN messages that await processing. */ if (HAL_CAN_Receive(&canHandle, CAN_FIFO0, 0) == HAL_OK) { /* check if this message has the configured CAN packet identifier. */ if ((rxMsgId & 0x80000000) == 0) { /* was an 11-bit CAN message received that matches? */ if ( (canHandle.pRxMsg->StdId == rxMsgId) && (canHandle.pRxMsg->IDE == CAN_ID_STD) ) { /* set flag that a packet with a matching CAN identifier was received. */ packetIdMatches = BLT_TRUE; } } else { /* negate the ID-type bit */ rxMsgId &= ~0x80000000; /* was an 29-bit CAN message received that matches? */ if ( (canHandle.pRxMsg->ExtId == rxMsgId) && (canHandle.pRxMsg->IDE == CAN_ID_EXT) ) { /* set flag that a packet with a matching CAN identifier was received. */ packetIdMatches = BLT_TRUE; } } /* only continue if a packet with a matching CAN identifier was received. */ if (packetIdMatches == BLT_TRUE) { /* copy the received package data. */ for (byteIdx = 0; byteIdx < canHandle.pRxMsg->DLC; byteIdx++) { data[byteIdx] = canHandle.pRxMsg->Data[byteIdx]; } *len = canHandle.pRxMsg->DLC; /* update the return value to indicate that new packet data was received. */ result = BLT_TRUE; } } /* Give the result back to the caller. */ return result; } /*** end of CanReceivePacket ***/ #endif /* BOOT_COM_CAN_ENABLE > 0 */ /*********************************** end of can.c **************************************/