openblt/Target/Source/ARMCM7_STM32F7/can.c

354 lines
15 KiB
C

/************************************************************************************//**
* \file Source/ARMCM7_STM32F7/can.c
* \brief Bootloader CAN communication interface source file.
* \ingroup Target_ARMCM7_STM32F7
* \internal
*----------------------------------------------------------------------------------------
* C O P Y R I G H T
*----------------------------------------------------------------------------------------
* Copyright (c) 2018 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 */
#if (BOOT_COM_CAN_ENABLE > 0)
#include "stm32f7xx.h" /* STM32 CPU and HAL header */
#include "stm32f7xx_ll_rcc.h" /* STM32 LL RCC header */
/****************************************************************************************
* Macro definitions
****************************************************************************************/
/** \brief Timeout for transmitting a CAN message in milliseconds. */
#define CAN_MSG_TX_TIMEOUT_MS (50u)
/* map the configured CAN channel index to the STM32's CAN peripheral */
#if (BOOT_COM_CAN_CHANNEL_INDEX == 0)
/** \brief Set CAN base address to CAN1. */
#define CAN_CHANNEL CAN1
#elif (BOOT_COM_CAN_CHANNEL_INDEX == 1)
/** \brief Set CAN base address to CAN2. */
#define CAN_CHANNEL CAN2
#endif
/****************************************************************************************
* 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 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_FilterTypeDef filterConfig;
blt_int32u rxMsgId = BOOT_COM_CAN_RX_MSG_ID;
blt_int32u rxFilterId, rxFilterMask;
/* the current implementation supports CAN1 and 2. throw an assertion error in case a
* different CAN channel is configured.
*/
ASSERT_CT((BOOT_COM_CAN_CHANNEL_INDEX == 0 || BOOT_COM_CAN_CHANNEL_INDEX == 1));
/* 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_CHANNEL;
canHandle.Init.TimeTriggeredMode = DISABLE;
canHandle.Init.AutoBusOff = DISABLE;
canHandle.Init.AutoWakeUp = DISABLE;
canHandle.Init.AutoRetransmission = ENABLE;
canHandle.Init.ReceiveFifoLocked = DISABLE;
canHandle.Init.TransmitFifoPriority = DISABLE;
canHandle.Init.Mode = CAN_MODE_NORMAL;
canHandle.Init.SyncJumpWidth = CAN_SJW_1TQ;
canHandle.Init.TimeSeg1 = ((blt_int32u)tseg1 - 1) << CAN_BTR_TS1_Pos;
canHandle.Init.TimeSeg2 = ((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.
*/
#if (BOOT_COM_CAN_CHANNEL_INDEX == 0)
/* filter 0 is the first filter assigned to the bxCAN master (CAN1) */
filterConfig.FilterBank = 0;
#else
/* filter 14 is the first filter assigned to the bxCAN slave (CAN2) */
filterConfig.FilterBank = 14;
#endif
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 = CAN_RX_FIFO0;
filterConfig.FilterActivation = ENABLE;
/* select the start slave bank number (for CAN1). this configuration assigns filter
* banks 0..13 to CAN1 and 14..27 to CAN2.
*/
filterConfig.SlaveStartFilterBank = 14;
(void)HAL_CAN_ConfigFilter(&canHandle, &filterConfig);
/* start the CAN peripheral. no need to evaluate the return value as there is nothing
* we can do about a faulty CAN controller. */
(void)HAL_CAN_Start(&canHandle);
} /*** 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_int32u txMsgId = BOOT_COM_CAN_TX_MSG_ID;
CAN_TxHeaderTypeDef txMsgHeader;
blt_int32u txMsgMailbox;
blt_int32u timeout;
HAL_StatusTypeDef txStatus;
/* configure the message that should be transmitted. */
if ((txMsgId & 0x80000000) == 0)
{
/* set the 11-bit CAN identifier. */
txMsgHeader.StdId = txMsgId;
txMsgHeader.IDE = CAN_ID_STD;
}
else
{
/* negate the ID-type bit */
txMsgId &= ~0x80000000;
/* set the 29-bit CAN identifier. */
txMsgHeader.ExtId = txMsgId;
txMsgHeader.IDE = CAN_ID_EXT;
}
txMsgHeader.RTR = CAN_RTR_DATA;
txMsgHeader.DLC = len;
/* submit the message for transmission. */
txStatus = HAL_CAN_AddTxMessage(&canHandle, &txMsgHeader, data,
(uint32_t *)&txMsgMailbox);
if (txStatus == HAL_OK)
{
/* determine timeout time for the transmit completion. */
timeout = TimerGet() + CAN_MSG_TX_TIMEOUT_MS;
/* poll for completion of the transmit operation. */
while (HAL_CAN_IsTxMessagePending(&canHandle, txMsgMailbox) != 0)
{
/* service the watchdog. */
CopService();
/* break loop upon timeout. this would indicate a hardware failure or no other
* nodes connected to the bus.
*/
if (TimerGet() > timeout)
{
break;
}
}
}
} /*** 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;
CAN_RxHeaderTypeDef rxMsgHeader;
if (HAL_CAN_GetRxMessage(&canHandle, CAN_RX_FIFO0, &rxMsgHeader, data) == 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 ( (rxMsgHeader.StdId == rxMsgId) &&
(rxMsgHeader.IDE == CAN_ID_STD) )
{
/* set flag that a packet with a matching CAN identifier was received. */
result = BLT_TRUE;
}
}
else
{
/* negate the ID-type bit. */
rxMsgId &= ~0x80000000;
/* was an 29-bit CAN message received that matches? */
if ( (rxMsgHeader.ExtId == rxMsgId) &&
(rxMsgHeader.IDE == CAN_ID_EXT) )
{
/* set flag that a packet with a matching CAN identifier was received. */
result = BLT_TRUE;
}
}
}
/* store the data length. */
if (result == BLT_TRUE)
{
*len = rxMsgHeader.DLC;
}
/* Give the result back to the caller. */
return result;
} /*** end of CanReceivePacket ***/
#endif /* BOOT_COM_CAN_ENABLE > 0 */
/*********************************** end of can.c **************************************/