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Last commit 20 Feb 2019 by mbed official

vendor/NXP/LPC2368/hal/can_api.c@10:3bc89ef62ce7, 2013-06-14 (annotated)

Committer:
emilmont
Date:
Fri Jun 14 17:49:17 2013 +0100
Revision:
10:3bc89ef62ce7
Unify mbed library sources

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 10:3bc89ef62ce7 1 /* mbed Microcontroller Library
emilmont 10:3bc89ef62ce7 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 10:3bc89ef62ce7 3 *
emilmont 10:3bc89ef62ce7 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 10:3bc89ef62ce7 5 * you may not use this file except in compliance with the License.
emilmont 10:3bc89ef62ce7 6 * You may obtain a copy of the License at
emilmont 10:3bc89ef62ce7 7 *
emilmont 10:3bc89ef62ce7 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 10:3bc89ef62ce7 9 *
emilmont 10:3bc89ef62ce7 10 * Unless required by applicable law or agreed to in writing, software
emilmont 10:3bc89ef62ce7 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 10:3bc89ef62ce7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 10:3bc89ef62ce7 13 * See the License for the specific language governing permissions and
emilmont 10:3bc89ef62ce7 14 * limitations under the License.
emilmont 10:3bc89ef62ce7 15 */
emilmont 10:3bc89ef62ce7 16 #include "can_api.h"
emilmont 10:3bc89ef62ce7 17 #include "cmsis.h"
emilmont 10:3bc89ef62ce7 18 #include "pinmap.h"
emilmont 10:3bc89ef62ce7 19 #include "error.h"
emilmont 10:3bc89ef62ce7 20
emilmont 10:3bc89ef62ce7 21 #include <math.h>
emilmont 10:3bc89ef62ce7 22 #include <string.h>
emilmont 10:3bc89ef62ce7 23
emilmont 10:3bc89ef62ce7 24 /* Acceptance filter mode in AFMR register */
emilmont 10:3bc89ef62ce7 25 #define ACCF_OFF 0x01
emilmont 10:3bc89ef62ce7 26 #define ACCF_BYPASS 0x02
emilmont 10:3bc89ef62ce7 27 #define ACCF_ON 0x00
emilmont 10:3bc89ef62ce7 28 #define ACCF_FULLCAN 0x04
emilmont 10:3bc89ef62ce7 29
emilmont 10:3bc89ef62ce7 30 /* There are several bit timing calculators on the internet.
emilmont 10:3bc89ef62ce7 31 http://www.port.de/engl/canprod/sv_req_form.html
emilmont 10:3bc89ef62ce7 32 http://www.kvaser.com/can/index.htm
emilmont 10:3bc89ef62ce7 33 */
emilmont 10:3bc89ef62ce7 34
emilmont 10:3bc89ef62ce7 35 static const PinMap PinMap_CAN_RD[] = {
emilmont 10:3bc89ef62ce7 36 {P0_0 , CAN_1, 1},
emilmont 10:3bc89ef62ce7 37 {P0_4 , CAN_2, 2},
emilmont 10:3bc89ef62ce7 38 {P0_21, CAN_1, 3},
emilmont 10:3bc89ef62ce7 39 {P2_7 , CAN_2, 1},
emilmont 10:3bc89ef62ce7 40 {NC , NC , 0}
emilmont 10:3bc89ef62ce7 41 };
emilmont 10:3bc89ef62ce7 42
emilmont 10:3bc89ef62ce7 43 static const PinMap PinMap_CAN_TD[] = {
emilmont 10:3bc89ef62ce7 44 {P0_1 , CAN_1, 1},
emilmont 10:3bc89ef62ce7 45 {P0_5 , CAN_2, 2},
emilmont 10:3bc89ef62ce7 46 {P0_22, CAN_1, 3},
emilmont 10:3bc89ef62ce7 47 {P2_8 , CAN_2, 1},
emilmont 10:3bc89ef62ce7 48 {NC , NC , 0}
emilmont 10:3bc89ef62ce7 49 };
emilmont 10:3bc89ef62ce7 50
emilmont 10:3bc89ef62ce7 51 // Type definition to hold a CAN message
emilmont 10:3bc89ef62ce7 52 struct CANMsg {
emilmont 10:3bc89ef62ce7 53 unsigned int reserved1 : 16;
emilmont 10:3bc89ef62ce7 54 unsigned int dlc : 4; // Bits 16..19: DLC - Data Length Counter
emilmont 10:3bc89ef62ce7 55 unsigned int reserved0 : 10;
emilmont 10:3bc89ef62ce7 56 unsigned int rtr : 1; // Bit 30: Set if this is a RTR message
emilmont 10:3bc89ef62ce7 57 unsigned int type : 1; // Bit 31: Set if this is a 29-bit ID message
emilmont 10:3bc89ef62ce7 58 unsigned int id; // CAN Message ID (11-bit or 29-bit)
emilmont 10:3bc89ef62ce7 59 unsigned char data[8]; // CAN Message Data Bytes 0-7
emilmont 10:3bc89ef62ce7 60 };
emilmont 10:3bc89ef62ce7 61 typedef struct CANMsg CANMsg;
emilmont 10:3bc89ef62ce7 62
emilmont 10:3bc89ef62ce7 63 static uint32_t can_disable(can_t *obj) {
emilmont 10:3bc89ef62ce7 64 uint32_t sm = obj->dev->MOD;
emilmont 10:3bc89ef62ce7 65 obj->dev->MOD |= 1;
emilmont 10:3bc89ef62ce7 66 return sm;
emilmont 10:3bc89ef62ce7 67 }
emilmont 10:3bc89ef62ce7 68
emilmont 10:3bc89ef62ce7 69 static inline void can_enable(can_t *obj) {
emilmont 10:3bc89ef62ce7 70 if (obj->dev->MOD & 1) {
emilmont 10:3bc89ef62ce7 71 obj->dev->MOD &= ~(1);
emilmont 10:3bc89ef62ce7 72 }
emilmont 10:3bc89ef62ce7 73 }
emilmont 10:3bc89ef62ce7 74
emilmont 10:3bc89ef62ce7 75 static int can_pclk(can_t *obj) {
emilmont 10:3bc89ef62ce7 76 int value = 0;
emilmont 10:3bc89ef62ce7 77 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 78 case CAN_1: value = (LPC_SC->PCLKSEL0 & (0x3 << 26)) >> 26; break;
emilmont 10:3bc89ef62ce7 79 case CAN_2: value = (LPC_SC->PCLKSEL0 & (0x3 << 28)) >> 28; break;
emilmont 10:3bc89ef62ce7 80 }
emilmont 10:3bc89ef62ce7 81
emilmont 10:3bc89ef62ce7 82 switch (value) {
emilmont 10:3bc89ef62ce7 83 case 1: return 1;
emilmont 10:3bc89ef62ce7 84 case 2: return 2;
emilmont 10:3bc89ef62ce7 85 case 3: return 6;
emilmont 10:3bc89ef62ce7 86 default: return 4;
emilmont 10:3bc89ef62ce7 87 }
emilmont 10:3bc89ef62ce7 88 }
emilmont 10:3bc89ef62ce7 89
emilmont 10:3bc89ef62ce7 90 // This table has the sampling points as close to 75% as possible. The first
emilmont 10:3bc89ef62ce7 91 // value is TSEG1, the second TSEG2.
emilmont 10:3bc89ef62ce7 92 static const int timing_pts[23][2] = {
emilmont 10:3bc89ef62ce7 93 {0x0, 0x0}, // 2, 50%
emilmont 10:3bc89ef62ce7 94 {0x1, 0x0}, // 3, 67%
emilmont 10:3bc89ef62ce7 95 {0x2, 0x0}, // 4, 75%
emilmont 10:3bc89ef62ce7 96 {0x3, 0x0}, // 5, 80%
emilmont 10:3bc89ef62ce7 97 {0x3, 0x1}, // 6, 67%
emilmont 10:3bc89ef62ce7 98 {0x4, 0x1}, // 7, 71%
emilmont 10:3bc89ef62ce7 99 {0x5, 0x1}, // 8, 75%
emilmont 10:3bc89ef62ce7 100 {0x6, 0x1}, // 9, 78%
emilmont 10:3bc89ef62ce7 101 {0x6, 0x2}, // 10, 70%
emilmont 10:3bc89ef62ce7 102 {0x7, 0x2}, // 11, 73%
emilmont 10:3bc89ef62ce7 103 {0x8, 0x2}, // 12, 75%
emilmont 10:3bc89ef62ce7 104 {0x9, 0x2}, // 13, 77%
emilmont 10:3bc89ef62ce7 105 {0x9, 0x3}, // 14, 71%
emilmont 10:3bc89ef62ce7 106 {0xA, 0x3}, // 15, 73%
emilmont 10:3bc89ef62ce7 107 {0xB, 0x3}, // 16, 75%
emilmont 10:3bc89ef62ce7 108 {0xC, 0x3}, // 17, 76%
emilmont 10:3bc89ef62ce7 109 {0xD, 0x3}, // 18, 78%
emilmont 10:3bc89ef62ce7 110 {0xD, 0x4}, // 19, 74%
emilmont 10:3bc89ef62ce7 111 {0xE, 0x4}, // 20, 75%
emilmont 10:3bc89ef62ce7 112 {0xF, 0x4}, // 21, 76%
emilmont 10:3bc89ef62ce7 113 {0xF, 0x5}, // 22, 73%
emilmont 10:3bc89ef62ce7 114 {0xF, 0x6}, // 23, 70%
emilmont 10:3bc89ef62ce7 115 {0xF, 0x7}, // 24, 67%
emilmont 10:3bc89ef62ce7 116 };
emilmont 10:3bc89ef62ce7 117
emilmont 10:3bc89ef62ce7 118 static unsigned int can_speed(unsigned int sclk, unsigned int pclk, unsigned int cclk, unsigned char psjw) {
emilmont 10:3bc89ef62ce7 119 uint32_t btr;
emilmont 10:3bc89ef62ce7 120 uint16_t brp = 0;
emilmont 10:3bc89ef62ce7 121 uint32_t calcbit;
emilmont 10:3bc89ef62ce7 122 uint32_t bitwidth;
emilmont 10:3bc89ef62ce7 123 int hit = 0;
emilmont 10:3bc89ef62ce7 124 int bits;
emilmont 10:3bc89ef62ce7 125
emilmont 10:3bc89ef62ce7 126 bitwidth = sclk / (pclk * cclk);
emilmont 10:3bc89ef62ce7 127
emilmont 10:3bc89ef62ce7 128 brp = bitwidth / 0x18;
emilmont 10:3bc89ef62ce7 129 while ((!hit) && (brp < bitwidth / 4)) {
emilmont 10:3bc89ef62ce7 130 brp++;
emilmont 10:3bc89ef62ce7 131 for (bits = 22; bits > 0; bits--) {
emilmont 10:3bc89ef62ce7 132 calcbit = (bits + 3) * (brp + 1);
emilmont 10:3bc89ef62ce7 133 if (calcbit == bitwidth) {
emilmont 10:3bc89ef62ce7 134 hit = 1;
emilmont 10:3bc89ef62ce7 135 break;
emilmont 10:3bc89ef62ce7 136 }
emilmont 10:3bc89ef62ce7 137 }
emilmont 10:3bc89ef62ce7 138 }
emilmont 10:3bc89ef62ce7 139
emilmont 10:3bc89ef62ce7 140 if (hit) {
emilmont 10:3bc89ef62ce7 141 btr = ((timing_pts[bits][1] << 20) & 0x00700000)
emilmont 10:3bc89ef62ce7 142 | ((timing_pts[bits][0] << 16) & 0x000F0000)
emilmont 10:3bc89ef62ce7 143 | ((psjw << 14) & 0x0000C000)
emilmont 10:3bc89ef62ce7 144 | ((brp << 0) & 0x000003FF);
emilmont 10:3bc89ef62ce7 145 } else {
emilmont 10:3bc89ef62ce7 146 btr = 0xFFFFFFFF;
emilmont 10:3bc89ef62ce7 147 }
emilmont 10:3bc89ef62ce7 148
emilmont 10:3bc89ef62ce7 149 return btr;
emilmont 10:3bc89ef62ce7 150 }
emilmont 10:3bc89ef62ce7 151
emilmont 10:3bc89ef62ce7 152 void can_init(can_t *obj, PinName rd, PinName td) {
emilmont 10:3bc89ef62ce7 153 CANName can_rd = (CANName)pinmap_peripheral(rd, PinMap_CAN_RD);
emilmont 10:3bc89ef62ce7 154 CANName can_td = (CANName)pinmap_peripheral(td, PinMap_CAN_TD);
emilmont 10:3bc89ef62ce7 155 obj->dev = (LPC_CAN_TypeDef *)pinmap_merge(can_rd, can_td);
emilmont 10:3bc89ef62ce7 156 if ((int)obj->dev == NC) {
emilmont 10:3bc89ef62ce7 157 error("CAN pin mapping failed");
emilmont 10:3bc89ef62ce7 158 }
emilmont 10:3bc89ef62ce7 159
emilmont 10:3bc89ef62ce7 160 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 161 case CAN_1: LPC_SC->PCONP |= 1 << 13; break;
emilmont 10:3bc89ef62ce7 162 case CAN_2: LPC_SC->PCONP |= 1 << 14; break;
emilmont 10:3bc89ef62ce7 163 }
emilmont 10:3bc89ef62ce7 164
emilmont 10:3bc89ef62ce7 165 pinmap_pinout(rd, PinMap_CAN_RD);
emilmont 10:3bc89ef62ce7 166 pinmap_pinout(td, PinMap_CAN_TD);
emilmont 10:3bc89ef62ce7 167
emilmont 10:3bc89ef62ce7 168 can_reset(obj);
emilmont 10:3bc89ef62ce7 169 obj->dev->IER = 0; // Disable Interrupts
emilmont 10:3bc89ef62ce7 170 can_frequency(obj, 100000);
emilmont 10:3bc89ef62ce7 171
emilmont 10:3bc89ef62ce7 172 LPC_CANAF->AFMR = ACCF_BYPASS; // Bypass Filter
emilmont 10:3bc89ef62ce7 173 }
emilmont 10:3bc89ef62ce7 174
emilmont 10:3bc89ef62ce7 175 void can_free(can_t *obj) {
emilmont 10:3bc89ef62ce7 176 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 177 case CAN_1: LPC_SC->PCONP &= ~(1 << 13); break;
emilmont 10:3bc89ef62ce7 178 case CAN_2: LPC_SC->PCONP &= ~(1 << 14); break;
emilmont 10:3bc89ef62ce7 179 }
emilmont 10:3bc89ef62ce7 180 }
emilmont 10:3bc89ef62ce7 181
emilmont 10:3bc89ef62ce7 182 int can_frequency(can_t *obj, int f) {
emilmont 10:3bc89ef62ce7 183 int pclk = can_pclk(obj);
emilmont 10:3bc89ef62ce7 184 int btr = can_speed(SystemCoreClock, pclk, (unsigned int)f, 1);
emilmont 10:3bc89ef62ce7 185
emilmont 10:3bc89ef62ce7 186 if (btr > 0) {
emilmont 10:3bc89ef62ce7 187 uint32_t modmask = can_disable(obj);
emilmont 10:3bc89ef62ce7 188 obj->dev->BTR = btr;
emilmont 10:3bc89ef62ce7 189 obj->dev->MOD = modmask;
emilmont 10:3bc89ef62ce7 190 return 1;
emilmont 10:3bc89ef62ce7 191 } else {
emilmont 10:3bc89ef62ce7 192 return 0;
emilmont 10:3bc89ef62ce7 193 }
emilmont 10:3bc89ef62ce7 194 }
emilmont 10:3bc89ef62ce7 195
emilmont 10:3bc89ef62ce7 196 int can_write(can_t *obj, CAN_Message msg, int cc) {
emilmont 10:3bc89ef62ce7 197 unsigned int CANStatus;
emilmont 10:3bc89ef62ce7 198 CANMsg m;
emilmont 10:3bc89ef62ce7 199
emilmont 10:3bc89ef62ce7 200 can_enable(obj);
emilmont 10:3bc89ef62ce7 201
emilmont 10:3bc89ef62ce7 202 m.id = msg.id ;
emilmont 10:3bc89ef62ce7 203 m.dlc = msg.len & 0xF;
emilmont 10:3bc89ef62ce7 204 m.rtr = msg.type;
emilmont 10:3bc89ef62ce7 205 m.type = msg.format;
emilmont 10:3bc89ef62ce7 206 memcpy(m.data, msg.data, msg.len);
emilmont 10:3bc89ef62ce7 207 const unsigned int *buf = (const unsigned int *)&m;
emilmont 10:3bc89ef62ce7 208
emilmont 10:3bc89ef62ce7 209 CANStatus = obj->dev->SR;
emilmont 10:3bc89ef62ce7 210 if (CANStatus & 0x00000004) {
emilmont 10:3bc89ef62ce7 211 obj->dev->TFI1 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 212 obj->dev->TID1 = buf[1];
emilmont 10:3bc89ef62ce7 213 obj->dev->TDA1 = buf[2];
emilmont 10:3bc89ef62ce7 214 obj->dev->TDB1 = buf[3];
emilmont 10:3bc89ef62ce7 215 if (cc) {
emilmont 10:3bc89ef62ce7 216 obj->dev->CMR = 0x30;
emilmont 10:3bc89ef62ce7 217 } else {
emilmont 10:3bc89ef62ce7 218 obj->dev->CMR = 0x21;
emilmont 10:3bc89ef62ce7 219 }
emilmont 10:3bc89ef62ce7 220 return 1;
emilmont 10:3bc89ef62ce7 221
emilmont 10:3bc89ef62ce7 222 } else if (CANStatus & 0x00000400) {
emilmont 10:3bc89ef62ce7 223 obj->dev->TFI2 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 224 obj->dev->TID2 = buf[1];
emilmont 10:3bc89ef62ce7 225 obj->dev->TDA2 = buf[2];
emilmont 10:3bc89ef62ce7 226 obj->dev->TDB2 = buf[3];
emilmont 10:3bc89ef62ce7 227 if (cc) {
emilmont 10:3bc89ef62ce7 228 obj->dev->CMR = 0x50;
emilmont 10:3bc89ef62ce7 229 } else {
emilmont 10:3bc89ef62ce7 230 obj->dev->CMR = 0x41;
emilmont 10:3bc89ef62ce7 231 }
emilmont 10:3bc89ef62ce7 232 return 1;
emilmont 10:3bc89ef62ce7 233
emilmont 10:3bc89ef62ce7 234 } else if (CANStatus & 0x00040000) {
emilmont 10:3bc89ef62ce7 235 obj->dev->TFI3 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 236 obj->dev->TID3 = buf[1];
emilmont 10:3bc89ef62ce7 237 obj->dev->TDA3 = buf[2];
emilmont 10:3bc89ef62ce7 238 obj->dev->TDB3 = buf[3];
emilmont 10:3bc89ef62ce7 239 if (cc) {
emilmont 10:3bc89ef62ce7 240 obj->dev->CMR = 0x90;
emilmont 10:3bc89ef62ce7 241 } else {
emilmont 10:3bc89ef62ce7 242 obj->dev->CMR = 0x81;
emilmont 10:3bc89ef62ce7 243 }
emilmont 10:3bc89ef62ce7 244 return 1;
emilmont 10:3bc89ef62ce7 245 }
emilmont 10:3bc89ef62ce7 246
emilmont 10:3bc89ef62ce7 247 return 0;
emilmont 10:3bc89ef62ce7 248 }
emilmont 10:3bc89ef62ce7 249
emilmont 10:3bc89ef62ce7 250 int can_read(can_t *obj, CAN_Message *msg) {
emilmont 10:3bc89ef62ce7 251 CANMsg x;
emilmont 10:3bc89ef62ce7 252 unsigned int *i = (unsigned int *)&x;
emilmont 10:3bc89ef62ce7 253
emilmont 10:3bc89ef62ce7 254 can_enable(obj);
emilmont 10:3bc89ef62ce7 255
emilmont 10:3bc89ef62ce7 256 if (obj->dev->GSR & 0x1) {
emilmont 10:3bc89ef62ce7 257 *i++ = obj->dev->RFS; // Frame
emilmont 10:3bc89ef62ce7 258 *i++ = obj->dev->RID; // ID
emilmont 10:3bc89ef62ce7 259 *i++ = obj->dev->RDA; // Data A
emilmont 10:3bc89ef62ce7 260 *i++ = obj->dev->RDB; // Data B
emilmont 10:3bc89ef62ce7 261 obj->dev->CMR = 0x04; // release receive buffer
emilmont 10:3bc89ef62ce7 262
emilmont 10:3bc89ef62ce7 263 msg->id = x.id;
emilmont 10:3bc89ef62ce7 264 msg->len = x.dlc;
emilmont 10:3bc89ef62ce7 265 msg->format = (x.type)? CANExtended : CANStandard;
emilmont 10:3bc89ef62ce7 266 msg->type = (x.rtr)? CANRemote: CANData;
emilmont 10:3bc89ef62ce7 267 memcpy(msg->data,x.data,x.dlc);
emilmont 10:3bc89ef62ce7 268 return 1;
emilmont 10:3bc89ef62ce7 269 }
emilmont 10:3bc89ef62ce7 270
emilmont 10:3bc89ef62ce7 271 return 0;
emilmont 10:3bc89ef62ce7 272 }
emilmont 10:3bc89ef62ce7 273
emilmont 10:3bc89ef62ce7 274 void can_reset(can_t *obj) {
emilmont 10:3bc89ef62ce7 275 can_disable(obj);
emilmont 10:3bc89ef62ce7 276 obj->dev->GSR = 0; // Reset error counter when CAN1MOD is in reset
emilmont 10:3bc89ef62ce7 277 }
emilmont 10:3bc89ef62ce7 278
emilmont 10:3bc89ef62ce7 279 unsigned char can_rderror(can_t *obj) {
emilmont 10:3bc89ef62ce7 280 return (obj->dev->GSR >> 16) & 0xFF;
emilmont 10:3bc89ef62ce7 281 }
emilmont 10:3bc89ef62ce7 282
emilmont 10:3bc89ef62ce7 283 unsigned char can_tderror(can_t *obj) {
emilmont 10:3bc89ef62ce7 284 return (obj->dev->GSR >> 24) & 0xFF;
emilmont 10:3bc89ef62ce7 285 }
emilmont 10:3bc89ef62ce7 286
emilmont 10:3bc89ef62ce7 287 void can_monitor(can_t *obj, int silent) {
emilmont 10:3bc89ef62ce7 288 uint32_t mod_mask = can_disable(obj);
emilmont 10:3bc89ef62ce7 289 if (silent) {
emilmont 10:3bc89ef62ce7 290 obj->dev->MOD |= (1 << 1);
emilmont 10:3bc89ef62ce7 291 } else {
emilmont 10:3bc89ef62ce7 292 obj->dev->MOD &= ~(1 << 1);
emilmont 10:3bc89ef62ce7 293 }
emilmont 10:3bc89ef62ce7 294 if (!(mod_mask & 1)) {
emilmont 10:3bc89ef62ce7 295 can_enable(obj);
emilmont 10:3bc89ef62ce7 296 }
emilmont 10:3bc89ef62ce7 297 }