5d95d0871f
Move can_bytes2dlc() and can_dlc2bytes() to a common CAN file that can be shared between socketCAN implementation and CAN character driver. This is the first step to simplifying the logic repeated in many CAN drivers. Signed-off-by: raiden00pl <raiden00@railab.me>
149 lines
3.8 KiB
C
149 lines
3.8 KiB
C
/****************************************************************************
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* drivers/can/can_common.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <nuttx/can/can_common.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: can_bytes2dlc
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*
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* Description:
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* In the CAN FD format, the coding of the DLC differs from the standard
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* CAN format. The DLC codes 0 to 8 have the same coding as in standard
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* CAN. But the codes 9 to 15 all imply a data field of 8 bytes with
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* standard CAN. In CAN FD mode, the values 9 to 15 are encoded to values
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* in the range 12 to 64.
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*
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* Input Parameters:
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* nbytes - the byte count to convert to a DLC value
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*
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* Returned Value:
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* The encoded DLC value corresponding to at least that number of bytes.
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*
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****************************************************************************/
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uint8_t can_bytes2dlc(uint8_t nbytes)
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{
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if (nbytes <= 8)
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{
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return nbytes;
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}
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#ifdef CONFIG_CAN_FD
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else if (nbytes <= 12)
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{
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return 9;
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}
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else if (nbytes <= 16)
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{
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return 10;
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}
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else if (nbytes <= 20)
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{
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return 11;
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}
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else if (nbytes <= 24)
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{
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return 12;
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}
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else if (nbytes <= 32)
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{
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return 13;
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}
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else if (nbytes <= 48)
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{
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return 14;
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}
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else /* if (nbytes <= 64) */
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{
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return 15;
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}
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#else
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else
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{
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return 8;
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}
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#endif
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}
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/****************************************************************************
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* Name: can_dlc2bytes
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*
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* Description:
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* In the CAN FD format, the coding of the DLC differs from the standard
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* CAN format. The DLC codes 0 to 8 have the same coding as in standard
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* CAN. But the codes 9 to 15 all imply a data field of 8 bytes with
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* standard CAN. In CAN FD mode, the values 9 to 15 are encoded to values
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* in the range 12 to 64.
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*
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* Input Parameters:
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* dlc - the DLC value to convert to a byte count
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*
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* Returned Value:
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* The number of bytes corresponding to the DLC value.
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*
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****************************************************************************/
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uint8_t can_dlc2bytes(uint8_t dlc)
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{
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if (dlc > 8)
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{
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#ifdef CONFIG_CAN_FD
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switch (dlc)
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{
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case 9:
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return 12;
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case 10:
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return 16;
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case 11:
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return 20;
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case 12:
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return 24;
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case 13:
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return 32;
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case 14:
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return 48;
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default:
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case 15:
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return 64;
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}
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#else
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return 8;
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#endif
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}
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return dlc;
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}
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