Joris Aerts / mbed-src

mbed library sources

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targets/hal/TARGET_NXP/TARGET_LPC176X/can_api.c@13:0645d8841f51, 2013-08-05 (annotated)

Committer:
bogdanm
Date:
Mon Aug 05 14:12:34 2013 +0300
Revision:
13:0645d8841f51
Parent:
vendor/NXP/LPC1768/hal/can_api.c@10:3bc89ef62ce7
Child:
15:4892fe388435
Update mbed sources to revision 64

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
emilmont 10:3bc89ef62ce7 18 #include "cmsis.h"
emilmont 10:3bc89ef62ce7 19 #include "pinmap.h"
emilmont 10:3bc89ef62ce7 20 #include "error.h"
emilmont 10:3bc89ef62ce7 21
emilmont 10:3bc89ef62ce7 22 #include <math.h>
emilmont 10:3bc89ef62ce7 23 #include <string.h>
emilmont 10:3bc89ef62ce7 24
emilmont 10:3bc89ef62ce7 25 /* Acceptance filter mode in AFMR register */
emilmont 10:3bc89ef62ce7 26 #define ACCF_OFF 0x01
emilmont 10:3bc89ef62ce7 27 #define ACCF_BYPASS 0x02
emilmont 10:3bc89ef62ce7 28 #define ACCF_ON 0x00
emilmont 10:3bc89ef62ce7 29 #define ACCF_FULLCAN 0x04
emilmont 10:3bc89ef62ce7 30
emilmont 10:3bc89ef62ce7 31 /* There are several bit timing calculators on the internet.
emilmont 10:3bc89ef62ce7 32 http://www.port.de/engl/canprod/sv_req_form.html
emilmont 10:3bc89ef62ce7 33 http://www.kvaser.com/can/index.htm
emilmont 10:3bc89ef62ce7 34 */
emilmont 10:3bc89ef62ce7 35
emilmont 10:3bc89ef62ce7 36 static const PinMap PinMap_CAN_RD[] = {
emilmont 10:3bc89ef62ce7 37 {P0_0 , CAN_1, 1},
emilmont 10:3bc89ef62ce7 38 {P0_4 , CAN_2, 2},
emilmont 10:3bc89ef62ce7 39 {P0_21, CAN_1, 3},
emilmont 10:3bc89ef62ce7 40 {P2_7 , CAN_2, 1},
emilmont 10:3bc89ef62ce7 41 {NC , NC , 0}
emilmont 10:3bc89ef62ce7 42 };
emilmont 10:3bc89ef62ce7 43
emilmont 10:3bc89ef62ce7 44 static const PinMap PinMap_CAN_TD[] = {
emilmont 10:3bc89ef62ce7 45 {P0_1 , CAN_1, 1},
emilmont 10:3bc89ef62ce7 46 {P0_5 , CAN_2, 2},
emilmont 10:3bc89ef62ce7 47 {P0_22, CAN_1, 3},
emilmont 10:3bc89ef62ce7 48 {P2_8 , CAN_2, 1},
emilmont 10:3bc89ef62ce7 49 {NC , NC , 0}
emilmont 10:3bc89ef62ce7 50 };
emilmont 10:3bc89ef62ce7 51
emilmont 10:3bc89ef62ce7 52 // Type definition to hold a CAN message
emilmont 10:3bc89ef62ce7 53 struct CANMsg {
emilmont 10:3bc89ef62ce7 54 unsigned int reserved1 : 16;
emilmont 10:3bc89ef62ce7 55 unsigned int dlc : 4; // Bits 16..19: DLC - Data Length Counter
emilmont 10:3bc89ef62ce7 56 unsigned int reserved0 : 10;
emilmont 10:3bc89ef62ce7 57 unsigned int rtr : 1; // Bit 30: Set if this is a RTR message
emilmont 10:3bc89ef62ce7 58 unsigned int type : 1; // Bit 31: Set if this is a 29-bit ID message
emilmont 10:3bc89ef62ce7 59 unsigned int id; // CAN Message ID (11-bit or 29-bit)
emilmont 10:3bc89ef62ce7 60 unsigned char data[8]; // CAN Message Data Bytes 0-7
emilmont 10:3bc89ef62ce7 61 };
emilmont 10:3bc89ef62ce7 62 typedef struct CANMsg CANMsg;
emilmont 10:3bc89ef62ce7 63
emilmont 10:3bc89ef62ce7 64 static uint32_t can_disable(can_t *obj) {
emilmont 10:3bc89ef62ce7 65 uint32_t sm = obj->dev->MOD;
emilmont 10:3bc89ef62ce7 66 obj->dev->MOD |= 1;
emilmont 10:3bc89ef62ce7 67 return sm;
emilmont 10:3bc89ef62ce7 68 }
emilmont 10:3bc89ef62ce7 69
emilmont 10:3bc89ef62ce7 70 static inline void can_enable(can_t *obj) {
emilmont 10:3bc89ef62ce7 71 if (obj->dev->MOD & 1) {
emilmont 10:3bc89ef62ce7 72 obj->dev->MOD &= ~(1);
emilmont 10:3bc89ef62ce7 73 }
emilmont 10:3bc89ef62ce7 74 }
emilmont 10:3bc89ef62ce7 75
emilmont 10:3bc89ef62ce7 76 static int can_pclk(can_t *obj) {
emilmont 10:3bc89ef62ce7 77 int value = 0;
emilmont 10:3bc89ef62ce7 78 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 79 case CAN_1: value = (LPC_SC->PCLKSEL0 & (0x3 << 26)) >> 26; break;
emilmont 10:3bc89ef62ce7 80 case CAN_2: value = (LPC_SC->PCLKSEL0 & (0x3 << 28)) >> 28; break;
emilmont 10:3bc89ef62ce7 81 }
emilmont 10:3bc89ef62ce7 82
emilmont 10:3bc89ef62ce7 83 switch (value) {
emilmont 10:3bc89ef62ce7 84 case 1: return 1;
emilmont 10:3bc89ef62ce7 85 case 2: return 2;
emilmont 10:3bc89ef62ce7 86 case 3: return 6;
emilmont 10:3bc89ef62ce7 87 default: return 4;
emilmont 10:3bc89ef62ce7 88 }
emilmont 10:3bc89ef62ce7 89 }
emilmont 10:3bc89ef62ce7 90
emilmont 10:3bc89ef62ce7 91 // This table has the sampling points as close to 75% as possible. The first
emilmont 10:3bc89ef62ce7 92 // value is TSEG1, the second TSEG2.
emilmont 10:3bc89ef62ce7 93 static const int timing_pts[23][2] = {
emilmont 10:3bc89ef62ce7 94 {0x0, 0x0}, // 2, 50%
emilmont 10:3bc89ef62ce7 95 {0x1, 0x0}, // 3, 67%
emilmont 10:3bc89ef62ce7 96 {0x2, 0x0}, // 4, 75%
emilmont 10:3bc89ef62ce7 97 {0x3, 0x0}, // 5, 80%
emilmont 10:3bc89ef62ce7 98 {0x3, 0x1}, // 6, 67%
emilmont 10:3bc89ef62ce7 99 {0x4, 0x1}, // 7, 71%
emilmont 10:3bc89ef62ce7 100 {0x5, 0x1}, // 8, 75%
emilmont 10:3bc89ef62ce7 101 {0x6, 0x1}, // 9, 78%
emilmont 10:3bc89ef62ce7 102 {0x6, 0x2}, // 10, 70%
emilmont 10:3bc89ef62ce7 103 {0x7, 0x2}, // 11, 73%
emilmont 10:3bc89ef62ce7 104 {0x8, 0x2}, // 12, 75%
emilmont 10:3bc89ef62ce7 105 {0x9, 0x2}, // 13, 77%
emilmont 10:3bc89ef62ce7 106 {0x9, 0x3}, // 14, 71%
emilmont 10:3bc89ef62ce7 107 {0xA, 0x3}, // 15, 73%
emilmont 10:3bc89ef62ce7 108 {0xB, 0x3}, // 16, 75%
emilmont 10:3bc89ef62ce7 109 {0xC, 0x3}, // 17, 76%
emilmont 10:3bc89ef62ce7 110 {0xD, 0x3}, // 18, 78%
emilmont 10:3bc89ef62ce7 111 {0xD, 0x4}, // 19, 74%
emilmont 10:3bc89ef62ce7 112 {0xE, 0x4}, // 20, 75%
emilmont 10:3bc89ef62ce7 113 {0xF, 0x4}, // 21, 76%
emilmont 10:3bc89ef62ce7 114 {0xF, 0x5}, // 22, 73%
emilmont 10:3bc89ef62ce7 115 {0xF, 0x6}, // 23, 70%
emilmont 10:3bc89ef62ce7 116 {0xF, 0x7}, // 24, 67%
emilmont 10:3bc89ef62ce7 117 };
emilmont 10:3bc89ef62ce7 118
emilmont 10:3bc89ef62ce7 119 static unsigned int can_speed(unsigned int sclk, unsigned int pclk, unsigned int cclk, unsigned char psjw) {
emilmont 10:3bc89ef62ce7 120 uint32_t btr;
emilmont 10:3bc89ef62ce7 121 uint16_t brp = 0;
emilmont 10:3bc89ef62ce7 122 uint32_t calcbit;
emilmont 10:3bc89ef62ce7 123 uint32_t bitwidth;
emilmont 10:3bc89ef62ce7 124 int hit = 0;
emilmont 10:3bc89ef62ce7 125 int bits;
emilmont 10:3bc89ef62ce7 126
emilmont 10:3bc89ef62ce7 127 bitwidth = sclk / (pclk * cclk);
emilmont 10:3bc89ef62ce7 128
emilmont 10:3bc89ef62ce7 129 brp = bitwidth / 0x18;
emilmont 10:3bc89ef62ce7 130 while ((!hit) && (brp < bitwidth / 4)) {
emilmont 10:3bc89ef62ce7 131 brp++;
emilmont 10:3bc89ef62ce7 132 for (bits = 22; bits > 0; bits--) {
emilmont 10:3bc89ef62ce7 133 calcbit = (bits + 3) * (brp + 1);
emilmont 10:3bc89ef62ce7 134 if (calcbit == bitwidth) {
emilmont 10:3bc89ef62ce7 135 hit = 1;
emilmont 10:3bc89ef62ce7 136 break;
emilmont 10:3bc89ef62ce7 137 }
emilmont 10:3bc89ef62ce7 138 }
emilmont 10:3bc89ef62ce7 139 }
emilmont 10:3bc89ef62ce7 140
emilmont 10:3bc89ef62ce7 141 if (hit) {
emilmont 10:3bc89ef62ce7 142 btr = ((timing_pts[bits][1] << 20) & 0x00700000)
emilmont 10:3bc89ef62ce7 143 | ((timing_pts[bits][0] << 16) & 0x000F0000)
emilmont 10:3bc89ef62ce7 144 | ((psjw << 14) & 0x0000C000)
emilmont 10:3bc89ef62ce7 145 | ((brp << 0) & 0x000003FF);
emilmont 10:3bc89ef62ce7 146 } else {
emilmont 10:3bc89ef62ce7 147 btr = 0xFFFFFFFF;
emilmont 10:3bc89ef62ce7 148 }
emilmont 10:3bc89ef62ce7 149
emilmont 10:3bc89ef62ce7 150 return btr;
emilmont 10:3bc89ef62ce7 151
emilmont 10:3bc89ef62ce7 152 }
emilmont 10:3bc89ef62ce7 153
emilmont 10:3bc89ef62ce7 154 void can_init(can_t *obj, PinName rd, PinName td) {
emilmont 10:3bc89ef62ce7 155 CANName can_rd = (CANName)pinmap_peripheral(rd, PinMap_CAN_RD);
emilmont 10:3bc89ef62ce7 156 CANName can_td = (CANName)pinmap_peripheral(td, PinMap_CAN_TD);
emilmont 10:3bc89ef62ce7 157 obj->dev = (LPC_CAN_TypeDef *)pinmap_merge(can_rd, can_td);
emilmont 10:3bc89ef62ce7 158 if ((int)obj->dev == NC) {
emilmont 10:3bc89ef62ce7 159 error("CAN pin mapping failed");
emilmont 10:3bc89ef62ce7 160 }
emilmont 10:3bc89ef62ce7 161
emilmont 10:3bc89ef62ce7 162 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 163 case CAN_1: LPC_SC->PCONP |= 1 << 13; break;
emilmont 10:3bc89ef62ce7 164 case CAN_2: LPC_SC->PCONP |= 1 << 14; break;
emilmont 10:3bc89ef62ce7 165 }
emilmont 10:3bc89ef62ce7 166
emilmont 10:3bc89ef62ce7 167 pinmap_pinout(rd, PinMap_CAN_RD);
emilmont 10:3bc89ef62ce7 168 pinmap_pinout(td, PinMap_CAN_TD);
emilmont 10:3bc89ef62ce7 169
emilmont 10:3bc89ef62ce7 170 can_reset(obj);
emilmont 10:3bc89ef62ce7 171 obj->dev->IER = 0; // Disable Interrupts
emilmont 10:3bc89ef62ce7 172 can_frequency(obj, 100000);
emilmont 10:3bc89ef62ce7 173
emilmont 10:3bc89ef62ce7 174 LPC_CANAF->AFMR = ACCF_BYPASS; // Bypass Filter
emilmont 10:3bc89ef62ce7 175 }
emilmont 10:3bc89ef62ce7 176
emilmont 10:3bc89ef62ce7 177 void can_free(can_t *obj) {
emilmont 10:3bc89ef62ce7 178 switch ((int)obj->dev) {
emilmont 10:3bc89ef62ce7 179 case CAN_1: LPC_SC->PCONP &= ~(1 << 13); break;
emilmont 10:3bc89ef62ce7 180 case CAN_2: LPC_SC->PCONP &= ~(1 << 14); break;
emilmont 10:3bc89ef62ce7 181 }
emilmont 10:3bc89ef62ce7 182 }
emilmont 10:3bc89ef62ce7 183
emilmont 10:3bc89ef62ce7 184 int can_frequency(can_t *obj, int f) {
emilmont 10:3bc89ef62ce7 185 int pclk = can_pclk(obj);
emilmont 10:3bc89ef62ce7 186
emilmont 10:3bc89ef62ce7 187 int btr = can_speed(SystemCoreClock, pclk, (unsigned int)f, 1);
emilmont 10:3bc89ef62ce7 188
emilmont 10:3bc89ef62ce7 189 if (btr > 0) {
emilmont 10:3bc89ef62ce7 190 uint32_t modmask = can_disable(obj);
emilmont 10:3bc89ef62ce7 191 obj->dev->BTR = btr;
emilmont 10:3bc89ef62ce7 192 obj->dev->MOD = modmask;
emilmont 10:3bc89ef62ce7 193 return 1;
emilmont 10:3bc89ef62ce7 194 } else {
emilmont 10:3bc89ef62ce7 195 return 0;
emilmont 10:3bc89ef62ce7 196 }
emilmont 10:3bc89ef62ce7 197 }
emilmont 10:3bc89ef62ce7 198
emilmont 10:3bc89ef62ce7 199 int can_write(can_t *obj, CAN_Message msg, int cc) {
emilmont 10:3bc89ef62ce7 200 unsigned int CANStatus;
emilmont 10:3bc89ef62ce7 201 CANMsg m;
emilmont 10:3bc89ef62ce7 202
emilmont 10:3bc89ef62ce7 203 can_enable(obj);
emilmont 10:3bc89ef62ce7 204
emilmont 10:3bc89ef62ce7 205 m.id = msg.id ;
emilmont 10:3bc89ef62ce7 206 m.dlc = msg.len & 0xF;
emilmont 10:3bc89ef62ce7 207 m.rtr = msg.type;
emilmont 10:3bc89ef62ce7 208 m.type = msg.format;
emilmont 10:3bc89ef62ce7 209 memcpy(m.data, msg.data, msg.len);
emilmont 10:3bc89ef62ce7 210 const unsigned int *buf = (const unsigned int *)&m;
emilmont 10:3bc89ef62ce7 211
emilmont 10:3bc89ef62ce7 212 CANStatus = obj->dev->SR;
emilmont 10:3bc89ef62ce7 213 if (CANStatus & 0x00000004) {
emilmont 10:3bc89ef62ce7 214 obj->dev->TFI1 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 215 obj->dev->TID1 = buf[1];
emilmont 10:3bc89ef62ce7 216 obj->dev->TDA1 = buf[2];
emilmont 10:3bc89ef62ce7 217 obj->dev->TDB1 = buf[3];
emilmont 10:3bc89ef62ce7 218 if(cc) {
emilmont 10:3bc89ef62ce7 219 obj->dev->CMR = 0x30;
emilmont 10:3bc89ef62ce7 220 } else {
emilmont 10:3bc89ef62ce7 221 obj->dev->CMR = 0x21;
emilmont 10:3bc89ef62ce7 222 }
emilmont 10:3bc89ef62ce7 223 return 1;
emilmont 10:3bc89ef62ce7 224
emilmont 10:3bc89ef62ce7 225 } else if (CANStatus & 0x00000400) {
emilmont 10:3bc89ef62ce7 226 obj->dev->TFI2 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 227 obj->dev->TID2 = buf[1];
emilmont 10:3bc89ef62ce7 228 obj->dev->TDA2 = buf[2];
emilmont 10:3bc89ef62ce7 229 obj->dev->TDB2 = buf[3];
emilmont 10:3bc89ef62ce7 230 if (cc) {
emilmont 10:3bc89ef62ce7 231 obj->dev->CMR = 0x50;
emilmont 10:3bc89ef62ce7 232 } else {
emilmont 10:3bc89ef62ce7 233 obj->dev->CMR = 0x41;
emilmont 10:3bc89ef62ce7 234 }
emilmont 10:3bc89ef62ce7 235 return 1;
emilmont 10:3bc89ef62ce7 236
emilmont 10:3bc89ef62ce7 237 } else if (CANStatus & 0x00040000) {
emilmont 10:3bc89ef62ce7 238 obj->dev->TFI3 = buf[0] & 0xC00F0000;
emilmont 10:3bc89ef62ce7 239 obj->dev->TID3 = buf[1];
emilmont 10:3bc89ef62ce7 240 obj->dev->TDA3 = buf[2];
emilmont 10:3bc89ef62ce7 241 obj->dev->TDB3 = buf[3];
emilmont 10:3bc89ef62ce7 242 if (cc) {
emilmont 10:3bc89ef62ce7 243 obj->dev->CMR = 0x90;
emilmont 10:3bc89ef62ce7 244 } else {
emilmont 10:3bc89ef62ce7 245 obj->dev->CMR = 0x81;
emilmont 10:3bc89ef62ce7 246 }
emilmont 10:3bc89ef62ce7 247 return 1;
emilmont 10:3bc89ef62ce7 248 }
emilmont 10:3bc89ef62ce7 249
emilmont 10:3bc89ef62ce7 250 return 0;
emilmont 10:3bc89ef62ce7 251 }
emilmont 10:3bc89ef62ce7 252
emilmont 10:3bc89ef62ce7 253 int can_read(can_t *obj, CAN_Message *msg) {
emilmont 10:3bc89ef62ce7 254 CANMsg x;
emilmont 10:3bc89ef62ce7 255 unsigned int *i = (unsigned int *)&x;
emilmont 10:3bc89ef62ce7 256
emilmont 10:3bc89ef62ce7 257 can_enable(obj);
emilmont 10:3bc89ef62ce7 258
emilmont 10:3bc89ef62ce7 259 if (obj->dev->GSR & 0x1) {
emilmont 10:3bc89ef62ce7 260 *i++ = obj->dev->RFS; // Frame
emilmont 10:3bc89ef62ce7 261 *i++ = obj->dev->RID; // ID
emilmont 10:3bc89ef62ce7 262 *i++ = obj->dev->RDA; // Data A
emilmont 10:3bc89ef62ce7 263 *i++ = obj->dev->RDB; // Data B
emilmont 10:3bc89ef62ce7 264 obj->dev->CMR = 0x04; // release receive buffer
emilmont 10:3bc89ef62ce7 265
emilmont 10:3bc89ef62ce7 266 msg->id = x.id;
emilmont 10:3bc89ef62ce7 267 msg->len = x.dlc;
emilmont 10:3bc89ef62ce7 268 msg->format = (x.type)? CANExtended : CANStandard;
emilmont 10:3bc89ef62ce7 269 msg->type = (x.rtr)? CANRemote: CANData;
emilmont 10:3bc89ef62ce7 270 memcpy(msg->data,x.data,x.dlc);
emilmont 10:3bc89ef62ce7 271 return 1;
emilmont 10:3bc89ef62ce7 272 }
emilmont 10:3bc89ef62ce7 273
emilmont 10:3bc89ef62ce7 274 return 0;
emilmont 10:3bc89ef62ce7 275 }
emilmont 10:3bc89ef62ce7 276
emilmont 10:3bc89ef62ce7 277 void can_reset(can_t *obj) {
emilmont 10:3bc89ef62ce7 278 can_disable(obj);
emilmont 10:3bc89ef62ce7 279 obj->dev->GSR = 0; // Reset error counter when CAN1MOD is in reset
emilmont 10:3bc89ef62ce7 280 }
emilmont 10:3bc89ef62ce7 281
emilmont 10:3bc89ef62ce7 282 unsigned char can_rderror(can_t *obj) {
emilmont 10:3bc89ef62ce7 283 return (obj->dev->GSR >> 16) & 0xFF;
emilmont 10:3bc89ef62ce7 284 }
emilmont 10:3bc89ef62ce7 285
emilmont 10:3bc89ef62ce7 286 unsigned char can_tderror(can_t *obj) {
emilmont 10:3bc89ef62ce7 287 return (obj->dev->GSR >> 24) & 0xFF;
emilmont 10:3bc89ef62ce7 288 }
emilmont 10:3bc89ef62ce7 289
emilmont 10:3bc89ef62ce7 290 void can_monitor(can_t *obj, int silent) {
emilmont 10:3bc89ef62ce7 291 uint32_t mod_mask = can_disable(obj);
emilmont 10:3bc89ef62ce7 292 if (silent) {
emilmont 10:3bc89ef62ce7 293 obj->dev->MOD |= (1 << 1);
emilmont 10:3bc89ef62ce7 294 } else {
emilmont 10:3bc89ef62ce7 295 obj->dev->MOD &= ~(1 << 1);
emilmont 10:3bc89ef62ce7 296 }
emilmont 10:3bc89ef62ce7 297 if (!(mod_mask & 1)) {
emilmont 10:3bc89ef62ce7 298 can_enable(obj);
emilmont 10:3bc89ef62ce7 299 }
emilmont 10:3bc89ef62ce7 300 }