?? 91x_can.c
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/******************** (C) COPYRIGHT 2006 STMicroelectronics ********************
* File Name : 91x_can.c
* Author : MCD Application Team
* Date First Issued : 05/18/2006 : Version 1.0
* Description : This file provides all the CAN software functions.
********************************************************************************
* History:
* 05/24/2006 : Version 1.1
* 05/18/2006 : Version 1.0
********************************************************************************
* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/
/* Includes ------------------------------------------------------------------*/
#include "91x_can.h"
#include "91x_scu.h"
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/* Macro Name : xxx_ID_MSK, xxx_ID_ARB */
/* Description : Form the Mask and Arbitration registers value to filter */
/* a range of identifiers or a fixed identifier, for standard*/
/* and extended IDs */
/*----------------------------------------------------------------------------*/
#define RANGE_ID_MSK(range_start, range_end) (~((range_end) - (range_start)))
#define RANGE_ID_ARB(range_start, range_end) ((range_start) & (range_end))
#define FIXED_ID_MSK(id) RANGE_ID_MSK((id), (id))
#define FIXED_ID_ARB(id) RANGE_ID_ARB((id), (id))
#define STD_RANGE_ID_MSK(range_start, range_end) ((u16)((RANGE_ID_MSK((range_start), (range_end)) & 0x7FF) << 2))
#define STD_RANGE_ID_ARB(range_start, range_end) ((u16)(RANGE_ID_ARB((range_start), (range_end)) << 2))
#define STD_FIXED_ID_MSK(id) ((u16)((FIXED_ID_MSK(id) & 0x7FF) << 2))
#define STD_FIXED_ID_ARB(id) ((u16)(FIXED_ID_ARB(id) << 2))
#define EXT_RANGE_ID_MSK_L(range_start, range_end) ((u16)(RANGE_ID_MSK((range_start), (range_end)) >> 11))
#define EXT_RANGE_ID_MSK_H(range_start, range_end) ((u16)(STD_RANGE_ID_MSK((range_start), (range_end)) | ((RANGE_ID_MSK((range_start), (range_end)) >> 27) & 0x03)))
#define EXT_RANGE_ID_ARB_L(range_start, range_end) ((u16)(RANGE_ID_ARB((range_start), (range_end)) >> 11))
#define EXT_RANGE_ID_ARB_H(range_start, range_end) ((u16)(STD_RANGE_ID_ARB((range_start), (range_end)) | ((RANGE_ID_ARB((range_start), (range_end)) >> 27) & 0x03)))
#define EXT_FIXED_ID_MSK_L(id) ((u16)(FIXED_ID_MSK(id) >> 11))
#define EXT_FIXED_ID_MSK_H(id) ((u16)(STD_FIXED_ID_MSK(id) | ((FIXED_ID_MSK(id) >> 27) & 0x03)))
#define EXT_FIXED_ID_ARB_L(id) ((u16)(FIXED_ID_ARB(id) >> 11))
#define EXT_FIXED_ID_ARB_H(id) ((u16)(STD_FIXED_ID_ARB(id) | ((FIXED_ID_ARB(id) >> 27) & 0x03)))
/* macro to format the timing register value from the timing parameters*/
#define CAN_TIMING(tseg1, tseg2, sjw, brp) ((((tseg2-1) & 0x07) << 12) | (((tseg1-1) & 0x0F) << 8) | (((sjw-1) & 0x03) << 6) | ((brp-1) & 0x3F))
/* Private variables ---------------------------------------------------------*/
/* array of pre-defined timing parameters for standard bitrates*/
u16 CanTimings[] = { /* value bitrate NTQ TSEG1 TSEG2 SJW BRP */
CAN_TIMING(11, 4, 4, 5), /* 0x3AC4 100 kbit/s 16 11 4 4 5 */
CAN_TIMING(11, 4, 4, 4), /* 0x3AC3 125 kbit/s 16 11 4 4 4 */
CAN_TIMING( 4, 3, 3, 4), /* 0x2383 250 kbit/s 8 4 3 3 4 */
CAN_TIMING(13, 2, 1, 1), /* 0x1C00 500 kbit/s 16 13 2 1 1 */
CAN_TIMING( 4, 3, 1, 1), /* 0x2300 1 Mbit/s 8 4 3 1 1 */
};
/* Private function prototypes -----------------------------------------------*/
static u32 GetFreeIF(void);
/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name : CAN_DeInit
* Description : Deinitializes the CAN peripheral registers to their default
* reset values.
* Input : None
* Output : None
* Return : None
*******************************************************************************/
void CAN_DeInit (void)
{
/* Reset the CAN registers values*/
SCU_APBPeriphReset(__CAN,ENABLE); /*CAN peripheral is under Reset */
SCU_APBPeriphReset(__CAN,DISABLE); /*CAN peripheral Reset off*/
}
/*******************************************************************************
* Function Name : CAN_Init
* Description : Initializes the CAN peripheral according to the specified
* parameters in the CAN_InitStruct.
* Input : CAN_InitStruct: pointer to a CAN_InitTypeDef structure that
* contains the configuration information for the CAN peripheral.
* Output : None
* Return : None
*******************************************************************************/
void CAN_Init(CAN_InitTypeDef* CAN_InitStruct)
{
CAN_EnterInitMode(CAN_CR_CCE | CAN_InitStruct->CAN_ConfigParameters);
CAN_SetBitrate(CAN_InitStruct->CAN_Bitrate);
CAN_LeaveInitMode();
CAN_LeaveTestMode();
}
/*******************************************************************************
* Function Name : CAN_StructInit
* Description : Fills each CAN_InitStruct member with its reset value.
* Input : CAN_InitStruct : pointer to a CAN_InitTypeDef structure which
* will be initialized.
* Output : None
* Return : None.
*******************************************************************************/
void CAN_StructInit(CAN_InitTypeDef* CAN_InitStruct)
{
/* Reset CAN init structure parameters values */
CAN_InitStruct->CAN_ConfigParameters = 0x0;
CAN_InitStruct->CAN_Bitrate = 0x2301;
}
/*******************************************************************************
* Function Name : CAN_SetBitrate
* Description : Setups a standard CAN bitrate.
* Input : bitrate: specifies the bit rate.
* Output : None
* Return : None
*******************************************************************************/
void CAN_SetBitrate(u32 bitrate)
{
CAN->BTR = CanTimings[bitrate]; /* write the predefined timing value */
CAN->BRPR = 0; /* clear the Extended Baud Rate Prescaler */
}
/*******************************************************************************
* Function Name : CAN_SetTiming
* Description : Setups the CAN timing with specific parameters
* Input : - tseg1: specifies Time Segment before the sample point.
* This parameter must be a number between 1 and 16.
* - tseg2: Time Segment after the sample point. This parameter
* must be a number between 1 and 8.
* - sjw: Synchronisation Jump Width. This parameter must be
* a number between 1 and 4.
* - brp: Baud Rate Prescaler. This parameter must be a number
* between 1 and 1024.
* Output : None
* Return : None
*******************************************************************************/
void CAN_SetTiming(u32 tseg1, u32 tseg2, u32 sjw, u32 brp)
{
CAN->BTR = CAN_TIMING(tseg1, tseg2, sjw, brp);
CAN->BRPR = ((brp-1) >> 6) & 0x0F;
}
/*******************************************************************************
* Function Name : GetFreeIF
* Description : Searchs the first free message interface, starting from 0.
* Input : None
* Output : None
* Return : A free message interface number (0 or 1) if found, else 2
*******************************************************************************/
static u32 GetFreeIF(void)
{
if ((CAN->sMsgObj[0].CRR & CAN_CRR_BUSY) == 0)
return 0;
else if ((CAN->sMsgObj[1].CRR & CAN_CRR_BUSY) == 0)
return 1;
else
return 2;
}
/*******************************************************************************
* Function Name : CAN_SetUnusedMsgObj
* Description : Configures the message object as unused
* Input : msgobj: specifies the Message object number, from 0 to 31.
* Output : None
* Return : An ErrorStatus enumuration value:
* - SUCCESS: Interface to treat the message
* - ERROR: No interface to treat the message
*******************************************************************************/
ErrorStatus CAN_SetUnusedMsgObj(u32 msgobj)
{
u32 msg_if=0;
if ((msg_if = GetFreeIF()) == 2)
{
return ERROR;
}
CAN->sMsgObj[msg_if].CMR = CAN_CMR_WRRD
| CAN_CMR_MASK
| CAN_CMR_ARB
| CAN_CMR_CONTROL
| CAN_CMR_DATAA
| CAN_CMR_DATAB;
CAN->sMsgObj[msg_if].M1R = 0;
CAN->sMsgObj[msg_if].M2R = 0;
CAN->sMsgObj[msg_if].A1R = 0;
CAN->sMsgObj[msg_if].A2R = 0;
CAN->sMsgObj[msg_if].MCR = 0;
CAN->sMsgObj[msg_if].DA1R = 0;
CAN->sMsgObj[msg_if].DA2R = 0;
CAN->sMsgObj[msg_if].DB1R = 0;
CAN->sMsgObj[msg_if].DB2R = 0;
CAN->sMsgObj[msg_if].CRR = 1 + msgobj;
return SUCCESS;
}
/*******************************************************************************
* Function Name : CAN_SetTxMsgObj
* Description : Configures the message object as TX.
* Input : - msgobj: specifies the Message object number, from 0 to 31.
* - idType: specifies the identifier type of the frames that
* will be transmitted using this message object.
* This parameter can be one of the following values:
* - CAN_STD_ID (standard ID, 11-bit)
* - CAN_EXT_ID (extended ID, 29-bit)
* Output : None
* Return : An ErrorStatus enumuration value:
* - SUCCESS: Interface to treat the message
* - ERROR: No interface to treat the message
*******************************************************************************/
ErrorStatus CAN_SetTxMsgObj(u32 msgobj, u32 idType)
{
u32 msg_if=0;
if ((msg_if = GetFreeIF()) == 2)
{
return ERROR;
}
CAN->sMsgObj[msg_if].CMR = CAN_CMR_WRRD
| CAN_CMR_MASK
| CAN_CMR_ARB
| CAN_CMR_CONTROL
| CAN_CMR_DATAA
| CAN_CMR_DATAB;
CAN->sMsgObj[msg_if].M1R = 0;
CAN->sMsgObj[msg_if].A1R = 0;
if (idType == CAN_STD_ID)
{
CAN->sMsgObj[msg_if].M2R = CAN_M2R_MDIR;
CAN->sMsgObj[msg_if].A2R = CAN_A2R_MSGVAL | CAN_A2R_DIR;
}
else
{
CAN->sMsgObj[msg_if].M2R = CAN_M2R_MDIR | CAN_M2R_MXTD;
CAN->sMsgObj[msg_if].A2R = CAN_A2R_MSGVAL | CAN_A2R_DIR | CAN_A2R_XTD;
}
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