+++ /dev/null
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#include "mbed_assert.h"
-#include "can_api.h"
-#include "cmsis.h"
-#include "pinmap.h"
-
-#include <math.h>
-#include <string.h>
-
-/* Acceptance filter mode in AFMR register */
-#define ACCF_OFF 0x01
-#define ACCF_BYPASS 0x02
-#define ACCF_ON 0x00
-#define ACCF_FULLCAN 0x04
-
-/* There are several bit timing calculators on the internet.
-http://www.port.de/engl/canprod/sv_req_form.html
-http://www.kvaser.com/can/index.htm
-*/
-
-static const PinMap PinMap_CAN_RD[] = {
- {P0_0 , CAN_1, 1},
- {P0_4 , CAN_2, 2},
- {P0_21, CAN_1, 3},
- {P2_7 , CAN_2, 1},
- {NC , NC , 0}
-};
-
-static const PinMap PinMap_CAN_TD[] = {
- {P0_1 , CAN_1, 1},
- {P0_5 , CAN_2, 2},
- {P0_22, CAN_1, 3},
- {P2_8 , CAN_2, 1},
- {NC , NC , 0}
-};
-
-// Type definition to hold a CAN message
-struct CANMsg {
- unsigned int reserved1 : 16;
- unsigned int dlc : 4; // Bits 16..19: DLC - Data Length Counter
- unsigned int reserved0 : 10;
- unsigned int rtr : 1; // Bit 30: Set if this is a RTR message
- unsigned int type : 1; // Bit 31: Set if this is a 29-bit ID message
- unsigned int id; // CAN Message ID (11-bit or 29-bit)
- unsigned char data[8]; // CAN Message Data Bytes 0-7
-};
-typedef struct CANMsg CANMsg;
-
-static uint32_t can_disable(can_t *obj) {
- uint32_t sm = obj->dev->MOD;
- obj->dev->MOD |= 1;
- return sm;
-}
-
-static inline void can_enable(can_t *obj) {
- if (obj->dev->MOD & 1) {
- obj->dev->MOD &= ~(1);
- }
-}
-
-int can_mode(can_t *obj, CanMode mode) {
- return 0; // not implemented
-}
-
-int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t handle) {
- return 0; // not implemented
-}
-
-static int can_pclk(can_t *obj) {
- int value = 0;
- switch ((int)obj->dev) {
- case CAN_1: value = (LPC_SC->PCLKSEL0 & (0x3 << 26)) >> 26; break;
- case CAN_2: value = (LPC_SC->PCLKSEL0 & (0x3 << 28)) >> 28; break;
- }
-
- switch (value) {
- case 1: return 1;
- case 2: return 2;
- case 3: return 6;
- default: return 4;
- }
-}
-
-// This table has the sampling points as close to 75% as possible. The first
-// value is TSEG1, the second TSEG2.
-static const int timing_pts[23][2] = {
- {0x0, 0x0}, // 2, 50%
- {0x1, 0x0}, // 3, 67%
- {0x2, 0x0}, // 4, 75%
- {0x3, 0x0}, // 5, 80%
- {0x3, 0x1}, // 6, 67%
- {0x4, 0x1}, // 7, 71%
- {0x5, 0x1}, // 8, 75%
- {0x6, 0x1}, // 9, 78%
- {0x6, 0x2}, // 10, 70%
- {0x7, 0x2}, // 11, 73%
- {0x8, 0x2}, // 12, 75%
- {0x9, 0x2}, // 13, 77%
- {0x9, 0x3}, // 14, 71%
- {0xA, 0x3}, // 15, 73%
- {0xB, 0x3}, // 16, 75%
- {0xC, 0x3}, // 17, 76%
- {0xD, 0x3}, // 18, 78%
- {0xD, 0x4}, // 19, 74%
- {0xE, 0x4}, // 20, 75%
- {0xF, 0x4}, // 21, 76%
- {0xF, 0x5}, // 22, 73%
- {0xF, 0x6}, // 23, 70%
- {0xF, 0x7}, // 24, 67%
-};
-
-static unsigned int can_speed(unsigned int sclk, unsigned int pclk, unsigned int cclk, unsigned char psjw) {
- uint32_t btr;
- uint16_t brp = 0;
- uint32_t calcbit;
- uint32_t bitwidth;
- int hit = 0;
- int bits;
-
- bitwidth = sclk / (pclk * cclk);
-
- brp = bitwidth / 0x18;
- while ((!hit) && (brp < bitwidth / 4)) {
- brp++;
- for (bits = 22; bits > 0; bits--) {
- calcbit = (bits + 3) * (brp + 1);
- if (calcbit == bitwidth) {
- hit = 1;
- break;
- }
- }
- }
-
- if (hit) {
- btr = ((timing_pts[bits][1] << 20) & 0x00700000)
- | ((timing_pts[bits][0] << 16) & 0x000F0000)
- | ((psjw << 14) & 0x0000C000)
- | ((brp << 0) & 0x000003FF);
- } else {
- btr = 0xFFFFFFFF;
- }
-
- return btr;
-}
-
-void can_init(can_t *obj, PinName rd, PinName td) {
- CANName can_rd = (CANName)pinmap_peripheral(rd, PinMap_CAN_RD);
- CANName can_td = (CANName)pinmap_peripheral(td, PinMap_CAN_TD);
- obj->dev = (LPC_CAN_TypeDef *)pinmap_merge(can_rd, can_td);
- MBED_ASSERT((int)obj->dev != NC);
-
- switch ((int)obj->dev) {
- case CAN_1: LPC_SC->PCONP |= 1 << 13; break;
- case CAN_2: LPC_SC->PCONP |= 1 << 14; break;
- }
-
- pinmap_pinout(rd, PinMap_CAN_RD);
- pinmap_pinout(td, PinMap_CAN_TD);
-
- can_reset(obj);
- obj->dev->IER = 0; // Disable Interrupts
- can_frequency(obj, 100000);
-
- LPC_CANAF->AFMR = ACCF_BYPASS; // Bypass Filter
-}
-
-void can_free(can_t *obj) {
- switch ((int)obj->dev) {
- case CAN_1: LPC_SC->PCONP &= ~(1 << 13); break;
- case CAN_2: LPC_SC->PCONP &= ~(1 << 14); break;
- }
-}
-
-int can_frequency(can_t *obj, int f) {
- int pclk = can_pclk(obj);
- int btr = can_speed(SystemCoreClock, pclk, (unsigned int)f, 1);
-
- if (btr > 0) {
- uint32_t modmask = can_disable(obj);
- obj->dev->BTR = btr;
- obj->dev->MOD = modmask;
- return 1;
- } else {
- return 0;
- }
-}
-
-int can_write(can_t *obj, CAN_Message msg, int cc) {
- unsigned int CANStatus;
- CANMsg m;
-
- can_enable(obj);
-
- m.id = msg.id ;
- m.dlc = msg.len & 0xF;
- m.rtr = msg.type;
- m.type = msg.format;
- memcpy(m.data, msg.data, msg.len);
- const unsigned int *buf = (const unsigned int *)&m;
-
- CANStatus = obj->dev->SR;
- if (CANStatus & 0x00000004) {
- obj->dev->TFI1 = buf[0] & 0xC00F0000;
- obj->dev->TID1 = buf[1];
- obj->dev->TDA1 = buf[2];
- obj->dev->TDB1 = buf[3];
- if (cc) {
- obj->dev->CMR = 0x30;
- } else {
- obj->dev->CMR = 0x21;
- }
- return 1;
-
- } else if (CANStatus & 0x00000400) {
- obj->dev->TFI2 = buf[0] & 0xC00F0000;
- obj->dev->TID2 = buf[1];
- obj->dev->TDA2 = buf[2];
- obj->dev->TDB2 = buf[3];
- if (cc) {
- obj->dev->CMR = 0x50;
- } else {
- obj->dev->CMR = 0x41;
- }
- return 1;
-
- } else if (CANStatus & 0x00040000) {
- obj->dev->TFI3 = buf[0] & 0xC00F0000;
- obj->dev->TID3 = buf[1];
- obj->dev->TDA3 = buf[2];
- obj->dev->TDB3 = buf[3];
- if (cc) {
- obj->dev->CMR = 0x90;
- } else {
- obj->dev->CMR = 0x81;
- }
- return 1;
- }
-
- return 0;
-}
-
-int can_read(can_t *obj, CAN_Message *msg, int handle) {
- CANMsg x;
- unsigned int *i = (unsigned int *)&x;
-
- can_enable(obj);
-
- if (obj->dev->GSR & 0x1) {
- *i++ = obj->dev->RFS; // Frame
- *i++ = obj->dev->RID; // ID
- *i++ = obj->dev->RDA; // Data A
- *i++ = obj->dev->RDB; // Data B
- obj->dev->CMR = 0x04; // release receive buffer
-
- msg->id = x.id;
- msg->len = x.dlc;
- msg->format = (x.type)? CANExtended : CANStandard;
- msg->type = (x.rtr)? CANRemote: CANData;
- memcpy(msg->data,x.data,x.dlc);
- return 1;
- }
-
- return 0;
-}
-
-void can_reset(can_t *obj) {
- can_disable(obj);
- obj->dev->GSR = 0; // Reset error counter when CAN1MOD is in reset
-}
-
-unsigned char can_rderror(can_t *obj) {
- return (obj->dev->GSR >> 16) & 0xFF;
-}
-
-unsigned char can_tderror(can_t *obj) {
- return (obj->dev->GSR >> 24) & 0xFF;
-}
-
-void can_monitor(can_t *obj, int silent) {
- uint32_t mod_mask = can_disable(obj);
- if (silent) {
- obj->dev->MOD |= (1 << 1);
- } else {
- obj->dev->MOD &= ~(1 << 1);
- }
- if (!(mod_mask & 1)) {
- can_enable(obj);
- }
-}