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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC408X/can_api.c@15:4892fe388435, 2013-08-07 (annotated)

Committer:
bogdanm
Date:
Wed Aug 07 16:43:59 2013 +0300
Revision:
15:4892fe388435
Child:
16:7da2369b400c
Added LPC4088 target and interrupt chaining code

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 15:4892fe388435 1 /* mbed Microcontroller Library
bogdanm 15:4892fe388435 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 15:4892fe388435 3 *
bogdanm 15:4892fe388435 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 15:4892fe388435 5 * you may not use this file except in compliance with the License.
bogdanm 15:4892fe388435 6 * You may obtain a copy of the License at
bogdanm 15:4892fe388435 7 *
bogdanm 15:4892fe388435 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 15:4892fe388435 9 *
bogdanm 15:4892fe388435 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 15:4892fe388435 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 15:4892fe388435 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 15:4892fe388435 13 * See the License for the specific language governing permissions and
bogdanm 15:4892fe388435 14 * limitations under the License.
bogdanm 15:4892fe388435 15 */
bogdanm 15:4892fe388435 16 #include <math.h>
bogdanm 15:4892fe388435 17 #include <string.h>
bogdanm 15:4892fe388435 18
bogdanm 15:4892fe388435 19 #include "can_api.h"
bogdanm 15:4892fe388435 20 #include "cmsis.h"
bogdanm 15:4892fe388435 21 #include "pinmap.h"
bogdanm 15:4892fe388435 22 #include "error.h"
bogdanm 15:4892fe388435 23
bogdanm 15:4892fe388435 24 /* Acceptance filter mode in AFMR register */
bogdanm 15:4892fe388435 25 #define ACCF_OFF 0x01
bogdanm 15:4892fe388435 26 #define ACCF_BYPASS 0x02
bogdanm 15:4892fe388435 27 #define ACCF_ON 0x00
bogdanm 15:4892fe388435 28 #define ACCF_FULLCAN 0x04
bogdanm 15:4892fe388435 29
bogdanm 15:4892fe388435 30 /* There are several bit timing calculators on the internet.
bogdanm 15:4892fe388435 31 http://www.port.de/engl/canprod/sv_req_form.html
bogdanm 15:4892fe388435 32 http://www.kvaser.com/can/index.htm
bogdanm 15:4892fe388435 33 */
bogdanm 15:4892fe388435 34
bogdanm 15:4892fe388435 35 static const PinMap PinMap_CAN_RD[] = {
bogdanm 15:4892fe388435 36 {P0_0 , CAN_1, 1},
bogdanm 15:4892fe388435 37 {P0_4 , CAN_2, 2},
bogdanm 15:4892fe388435 38 {P0_21, CAN_1, 4},
bogdanm 15:4892fe388435 39 {P2_7 , CAN_2, 1},
bogdanm 15:4892fe388435 40 {NC , NC , 0}
bogdanm 15:4892fe388435 41 };
bogdanm 15:4892fe388435 42
bogdanm 15:4892fe388435 43 static const PinMap PinMap_CAN_TD[] = {
bogdanm 15:4892fe388435 44 {P0_1 , CAN_1, 1},
bogdanm 15:4892fe388435 45 {P0_5 , CAN_2, 2},
bogdanm 15:4892fe388435 46 {P0_22, CAN_1, 4},
bogdanm 15:4892fe388435 47 {P2_8 , CAN_2, 1},
bogdanm 15:4892fe388435 48 {NC , NC , 0}
bogdanm 15:4892fe388435 49 };
bogdanm 15:4892fe388435 50
bogdanm 15:4892fe388435 51 // Type definition to hold a CAN message
bogdanm 15:4892fe388435 52 struct CANMsg {
bogdanm 15:4892fe388435 53 unsigned int reserved1 : 16;
bogdanm 15:4892fe388435 54 unsigned int dlc : 4; // Bits 16..19: DLC - Data Length Counter
bogdanm 15:4892fe388435 55 unsigned int reserved0 : 10;
bogdanm 15:4892fe388435 56 unsigned int rtr : 1; // Bit 30: Set if this is a RTR message
bogdanm 15:4892fe388435 57 unsigned int type : 1; // Bit 31: Set if this is a 29-bit ID message
bogdanm 15:4892fe388435 58 unsigned int id; // CAN Message ID (11-bit or 29-bit)
bogdanm 15:4892fe388435 59 unsigned char data[8]; // CAN Message Data Bytes 0-7
bogdanm 15:4892fe388435 60 };
bogdanm 15:4892fe388435 61 typedef struct CANMsg CANMsg;
bogdanm 15:4892fe388435 62
bogdanm 15:4892fe388435 63 static uint32_t can_disable(can_t *obj) {
bogdanm 15:4892fe388435 64 uint32_t sm = obj->dev->MOD;
bogdanm 15:4892fe388435 65 obj->dev->MOD |= 1;
bogdanm 15:4892fe388435 66 return sm;
bogdanm 15:4892fe388435 67 }
bogdanm 15:4892fe388435 68
bogdanm 15:4892fe388435 69 static inline void can_enable(can_t *obj) {
bogdanm 15:4892fe388435 70 if (obj->dev->MOD & 1) {
bogdanm 15:4892fe388435 71 obj->dev->MOD &= ~(1);
bogdanm 15:4892fe388435 72 }
bogdanm 15:4892fe388435 73 }
bogdanm 15:4892fe388435 74
bogdanm 15:4892fe388435 75 // This table has the sampling points as close to 75% as possible. The first
bogdanm 15:4892fe388435 76 // value is TSEG1, the second TSEG2.
bogdanm 15:4892fe388435 77 static const int timing_pts[23][2] = {
bogdanm 15:4892fe388435 78 {0x0, 0x0}, // 2, 50%
bogdanm 15:4892fe388435 79 {0x1, 0x0}, // 3, 67%
bogdanm 15:4892fe388435 80 {0x2, 0x0}, // 4, 75%
bogdanm 15:4892fe388435 81 {0x3, 0x0}, // 5, 80%
bogdanm 15:4892fe388435 82 {0x3, 0x1}, // 6, 67%
bogdanm 15:4892fe388435 83 {0x4, 0x1}, // 7, 71%
bogdanm 15:4892fe388435 84 {0x5, 0x1}, // 8, 75%
bogdanm 15:4892fe388435 85 {0x6, 0x1}, // 9, 78%
bogdanm 15:4892fe388435 86 {0x6, 0x2}, // 10, 70%
bogdanm 15:4892fe388435 87 {0x7, 0x2}, // 11, 73%
bogdanm 15:4892fe388435 88 {0x8, 0x2}, // 12, 75%
bogdanm 15:4892fe388435 89 {0x9, 0x2}, // 13, 77%
bogdanm 15:4892fe388435 90 {0x9, 0x3}, // 14, 71%
bogdanm 15:4892fe388435 91 {0xA, 0x3}, // 15, 73%
bogdanm 15:4892fe388435 92 {0xB, 0x3}, // 16, 75%
bogdanm 15:4892fe388435 93 {0xC, 0x3}, // 17, 76%
bogdanm 15:4892fe388435 94 {0xD, 0x3}, // 18, 78%
bogdanm 15:4892fe388435 95 {0xD, 0x4}, // 19, 74%
bogdanm 15:4892fe388435 96 {0xE, 0x4}, // 20, 75%
bogdanm 15:4892fe388435 97 {0xF, 0x4}, // 21, 76%
bogdanm 15:4892fe388435 98 {0xF, 0x5}, // 22, 73%
bogdanm 15:4892fe388435 99 {0xF, 0x6}, // 23, 70%
bogdanm 15:4892fe388435 100 {0xF, 0x7}, // 24, 67%
bogdanm 15:4892fe388435 101 };
bogdanm 15:4892fe388435 102
bogdanm 15:4892fe388435 103 static unsigned int can_speed(unsigned int sclk, unsigned int pclk, unsigned int cclk, unsigned char psjw) {
bogdanm 15:4892fe388435 104 uint32_t btr;
bogdanm 15:4892fe388435 105 uint16_t brp = 0;
bogdanm 15:4892fe388435 106 uint32_t calcbit;
bogdanm 15:4892fe388435 107 uint32_t bitwidth;
bogdanm 15:4892fe388435 108 int hit = 0;
bogdanm 15:4892fe388435 109 int bits;
bogdanm 15:4892fe388435 110
bogdanm 15:4892fe388435 111 bitwidth = sclk / (pclk * cclk);
bogdanm 15:4892fe388435 112
bogdanm 15:4892fe388435 113 brp = bitwidth / 0x18;
bogdanm 15:4892fe388435 114 while ((!hit) && (brp < bitwidth / 4)) {
bogdanm 15:4892fe388435 115 brp++;
bogdanm 15:4892fe388435 116 for (bits = 22; bits > 0; bits--) {
bogdanm 15:4892fe388435 117 calcbit = (bits + 3) * (brp + 1);
bogdanm 15:4892fe388435 118 if (calcbit == bitwidth) {
bogdanm 15:4892fe388435 119 hit = 1;
bogdanm 15:4892fe388435 120 break;
bogdanm 15:4892fe388435 121 }
bogdanm 15:4892fe388435 122 }
bogdanm 15:4892fe388435 123 }
bogdanm 15:4892fe388435 124
bogdanm 15:4892fe388435 125 if (hit) {
bogdanm 15:4892fe388435 126 btr = ((timing_pts[bits][1] << 20) & 0x00700000)
bogdanm 15:4892fe388435 127 | ((timing_pts[bits][0] << 16) & 0x000F0000)
bogdanm 15:4892fe388435 128 | ((psjw << 14) & 0x0000C000)
bogdanm 15:4892fe388435 129 | ((brp << 0) & 0x000003FF);
bogdanm 15:4892fe388435 130 } else {
bogdanm 15:4892fe388435 131 btr = 0xFFFFFFFF;
bogdanm 15:4892fe388435 132 }
bogdanm 15:4892fe388435 133
bogdanm 15:4892fe388435 134 return btr;
bogdanm 15:4892fe388435 135 }
bogdanm 15:4892fe388435 136
bogdanm 15:4892fe388435 137 void can_init(can_t *obj, PinName rd, PinName td) {
bogdanm 15:4892fe388435 138 CANName can_rd = (CANName)pinmap_peripheral(rd, PinMap_CAN_RD);
bogdanm 15:4892fe388435 139 CANName can_td = (CANName)pinmap_peripheral(td, PinMap_CAN_TD);
bogdanm 15:4892fe388435 140 obj->dev = (LPC_CAN_TypeDef *)pinmap_merge(can_rd, can_td);
bogdanm 15:4892fe388435 141 if ((int)obj->dev == NC) {
bogdanm 15:4892fe388435 142 error("CAN pin mapping failed");
bogdanm 15:4892fe388435 143 }
bogdanm 15:4892fe388435 144
bogdanm 15:4892fe388435 145 switch ((int)obj->dev) {
bogdanm 15:4892fe388435 146 case CAN_1: LPC_SC->PCONP |= 1 << 13; break;
bogdanm 15:4892fe388435 147 case CAN_2: LPC_SC->PCONP |= 1 << 14; break;
bogdanm 15:4892fe388435 148 }
bogdanm 15:4892fe388435 149
bogdanm 15:4892fe388435 150 pinmap_pinout(rd, PinMap_CAN_RD);
bogdanm 15:4892fe388435 151 pinmap_pinout(td, PinMap_CAN_TD);
bogdanm 15:4892fe388435 152
bogdanm 15:4892fe388435 153 can_reset(obj);
bogdanm 15:4892fe388435 154 obj->dev->IER = 0; // Disable Interrupts
bogdanm 15:4892fe388435 155 can_frequency(obj, 100000);
bogdanm 15:4892fe388435 156
bogdanm 15:4892fe388435 157 LPC_CANAF->AFMR = ACCF_BYPASS; // Bypass Filter
bogdanm 15:4892fe388435 158 }
bogdanm 15:4892fe388435 159
bogdanm 15:4892fe388435 160 void can_free(can_t *obj) {
bogdanm 15:4892fe388435 161 switch ((int)obj->dev) {
bogdanm 15:4892fe388435 162 case CAN_1: LPC_SC->PCONP &= ~(1 << 13); break;
bogdanm 15:4892fe388435 163 case CAN_2: LPC_SC->PCONP &= ~(1 << 14); break;
bogdanm 15:4892fe388435 164 }
bogdanm 15:4892fe388435 165 }
bogdanm 15:4892fe388435 166
bogdanm 15:4892fe388435 167 int can_frequency(can_t *obj, int f) {
bogdanm 15:4892fe388435 168 int pclk = PeripheralClock;
bogdanm 15:4892fe388435 169 int btr = can_speed(SystemCoreClock, pclk, (unsigned int)f, 1);
bogdanm 15:4892fe388435 170
bogdanm 15:4892fe388435 171 if (btr > 0) {
bogdanm 15:4892fe388435 172 uint32_t modmask = can_disable(obj);
bogdanm 15:4892fe388435 173 obj->dev->BTR = btr;
bogdanm 15:4892fe388435 174 obj->dev->MOD = modmask;
bogdanm 15:4892fe388435 175 return 1;
bogdanm 15:4892fe388435 176 } else {
bogdanm 15:4892fe388435 177 return 0;
bogdanm 15:4892fe388435 178 }
bogdanm 15:4892fe388435 179 }
bogdanm 15:4892fe388435 180
bogdanm 15:4892fe388435 181 int can_write(can_t *obj, CAN_Message msg, int cc) {
bogdanm 15:4892fe388435 182 unsigned int CANStatus;
bogdanm 15:4892fe388435 183 CANMsg m;
bogdanm 15:4892fe388435 184
bogdanm 15:4892fe388435 185 can_enable(obj);
bogdanm 15:4892fe388435 186
bogdanm 15:4892fe388435 187 m.id = msg.id ;
bogdanm 15:4892fe388435 188 m.dlc = msg.len & 0xF;
bogdanm 15:4892fe388435 189 m.rtr = msg.type;
bogdanm 15:4892fe388435 190 m.type = msg.format;
bogdanm 15:4892fe388435 191 memcpy(m.data, msg.data, msg.len);
bogdanm 15:4892fe388435 192 const unsigned int *buf = (const unsigned int *)&m;
bogdanm 15:4892fe388435 193
bogdanm 15:4892fe388435 194 CANStatus = obj->dev->SR;
bogdanm 15:4892fe388435 195 if (CANStatus & 0x00000004) {
bogdanm 15:4892fe388435 196 obj->dev->TFI1 = buf[0] & 0xC00F0000;
bogdanm 15:4892fe388435 197 obj->dev->TID1 = buf[1];
bogdanm 15:4892fe388435 198 obj->dev->TDA1 = buf[2];
bogdanm 15:4892fe388435 199 obj->dev->TDB1 = buf[3];
bogdanm 15:4892fe388435 200 if(cc) {
bogdanm 15:4892fe388435 201 obj->dev->CMR = 0x30;
bogdanm 15:4892fe388435 202 } else {
bogdanm 15:4892fe388435 203 obj->dev->CMR = 0x21;
bogdanm 15:4892fe388435 204 }
bogdanm 15:4892fe388435 205 return 1;
bogdanm 15:4892fe388435 206
bogdanm 15:4892fe388435 207 } else if (CANStatus & 0x00000400) {
bogdanm 15:4892fe388435 208 obj->dev->TFI2 = buf[0] & 0xC00F0000;
bogdanm 15:4892fe388435 209 obj->dev->TID2 = buf[1];
bogdanm 15:4892fe388435 210 obj->dev->TDA2 = buf[2];
bogdanm 15:4892fe388435 211 obj->dev->TDB2 = buf[3];
bogdanm 15:4892fe388435 212 if (cc) {
bogdanm 15:4892fe388435 213 obj->dev->CMR = 0x50;
bogdanm 15:4892fe388435 214 } else {
bogdanm 15:4892fe388435 215 obj->dev->CMR = 0x41;
bogdanm 15:4892fe388435 216 }
bogdanm 15:4892fe388435 217 return 1;
bogdanm 15:4892fe388435 218
bogdanm 15:4892fe388435 219 } else if (CANStatus & 0x00040000) {
bogdanm 15:4892fe388435 220 obj->dev->TFI3 = buf[0] & 0xC00F0000;
bogdanm 15:4892fe388435 221 obj->dev->TID3 = buf[1];
bogdanm 15:4892fe388435 222 obj->dev->TDA3 = buf[2];
bogdanm 15:4892fe388435 223 obj->dev->TDB3 = buf[3];
bogdanm 15:4892fe388435 224 if (cc) {
bogdanm 15:4892fe388435 225 obj->dev->CMR = 0x90;
bogdanm 15:4892fe388435 226 } else {
bogdanm 15:4892fe388435 227 obj->dev->CMR = 0x81;
bogdanm 15:4892fe388435 228 }
bogdanm 15:4892fe388435 229 return 1;
bogdanm 15:4892fe388435 230 }
bogdanm 15:4892fe388435 231
bogdanm 15:4892fe388435 232 return 0;
bogdanm 15:4892fe388435 233 }
bogdanm 15:4892fe388435 234
bogdanm 15:4892fe388435 235 int can_read(can_t *obj, CAN_Message *msg) {
bogdanm 15:4892fe388435 236 CANMsg x;
bogdanm 15:4892fe388435 237 unsigned int *i = (unsigned int *)&x;
bogdanm 15:4892fe388435 238
bogdanm 15:4892fe388435 239 can_enable(obj);
bogdanm 15:4892fe388435 240
bogdanm 15:4892fe388435 241 if (obj->dev->GSR & 0x1) {
bogdanm 15:4892fe388435 242 *i++ = obj->dev->RFS; // Frame
bogdanm 15:4892fe388435 243 *i++ = obj->dev->RID; // ID
bogdanm 15:4892fe388435 244 *i++ = obj->dev->RDA; // Data A
bogdanm 15:4892fe388435 245 *i++ = obj->dev->RDB; // Data B
bogdanm 15:4892fe388435 246 obj->dev->CMR = 0x04; // release receive buffer
bogdanm 15:4892fe388435 247
bogdanm 15:4892fe388435 248 msg->id = x.id;
bogdanm 15:4892fe388435 249 msg->len = x.dlc;
bogdanm 15:4892fe388435 250 msg->format = (x.type)? CANExtended : CANStandard;
bogdanm 15:4892fe388435 251 msg->type = (x.rtr)? CANRemote: CANData;
bogdanm 15:4892fe388435 252 memcpy(msg->data,x.data,x.dlc);
bogdanm 15:4892fe388435 253 return 1;
bogdanm 15:4892fe388435 254 }
bogdanm 15:4892fe388435 255
bogdanm 15:4892fe388435 256 return 0;
bogdanm 15:4892fe388435 257 }
bogdanm 15:4892fe388435 258
bogdanm 15:4892fe388435 259 void can_reset(can_t *obj) {
bogdanm 15:4892fe388435 260 can_disable(obj);
bogdanm 15:4892fe388435 261 obj->dev->GSR = 0; // Reset error counter when CAN1MOD is in reset
bogdanm 15:4892fe388435 262 }
bogdanm 15:4892fe388435 263
bogdanm 15:4892fe388435 264 unsigned char can_rderror(can_t *obj) {
bogdanm 15:4892fe388435 265 return (obj->dev->GSR >> 16) & 0xFF;
bogdanm 15:4892fe388435 266 }
bogdanm 15:4892fe388435 267
bogdanm 15:4892fe388435 268 unsigned char can_tderror(can_t *obj) {
bogdanm 15:4892fe388435 269 return (obj->dev->GSR >> 24) & 0xFF;
bogdanm 15:4892fe388435 270 }
bogdanm 15:4892fe388435 271
bogdanm 15:4892fe388435 272 void can_monitor(can_t *obj, int silent) {
bogdanm 15:4892fe388435 273 uint32_t mod_mask = can_disable(obj);
bogdanm 15:4892fe388435 274 if (silent) {
bogdanm 15:4892fe388435 275 obj->dev->MOD |= (1 << 1);
bogdanm 15:4892fe388435 276 } else {
bogdanm 15:4892fe388435 277 obj->dev->MOD &= ~(1 << 1);
bogdanm 15:4892fe388435 278 }
bogdanm 15:4892fe388435 279 if (!(mod_mask & 1)) {
bogdanm 15:4892fe388435 280 can_enable(obj);
bogdanm 15:4892fe388435 281 }
bogdanm 15:4892fe388435 282 }