rik te winkel / mbed-dev

Forked mbed-dev as I use an 20 pins stm32F042 and not the 32 pins version

Dependents:   Numitron_clock

Fork of mbed-dev by mbed official

targets/TARGET_NXP/TARGET_LPC23XX/can_api.c@153:0a78729d3229, 2017-01-22 (annotated)

Committer:
riktw
Date:
Sun Jan 22 22:20:36 2017 +0000
Revision:
153:0a78729d3229
Parent:
149:156823d33999 
Back to 8Mhz clock. Revision 1.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "can_api.h"
<> 144:ef7eb2e8f9f7 18 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 19 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #include <math.h>
<> 144:ef7eb2e8f9f7 22 #include <string.h>
<> 144:ef7eb2e8f9f7 23
<> 144:ef7eb2e8f9f7 24 /* Acceptance filter mode in AFMR register */
<> 144:ef7eb2e8f9f7 25 #define ACCF_OFF 0x01
<> 144:ef7eb2e8f9f7 26 #define ACCF_BYPASS 0x02
<> 144:ef7eb2e8f9f7 27 #define ACCF_ON 0x00
<> 144:ef7eb2e8f9f7 28 #define ACCF_FULLCAN 0x04
<> 144:ef7eb2e8f9f7 29
<> 144:ef7eb2e8f9f7 30 /* There are several bit timing calculators on the internet.
<> 144:ef7eb2e8f9f7 31 http://www.port.de/engl/canprod/sv_req_form.html
<> 144:ef7eb2e8f9f7 32 http://www.kvaser.com/can/index.htm
<> 144:ef7eb2e8f9f7 33 */
<> 144:ef7eb2e8f9f7 34
<> 144:ef7eb2e8f9f7 35 static const PinMap PinMap_CAN_RD[] = {
<> 144:ef7eb2e8f9f7 36 {P0_0 , CAN_1, 1},
<> 144:ef7eb2e8f9f7 37 {P0_4 , CAN_2, 2},
<> 144:ef7eb2e8f9f7 38 {P0_21, CAN_1, 3},
<> 144:ef7eb2e8f9f7 39 {P2_7 , CAN_2, 1},
<> 144:ef7eb2e8f9f7 40 {NC , NC , 0}
<> 144:ef7eb2e8f9f7 41 };
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 static const PinMap PinMap_CAN_TD[] = {
<> 144:ef7eb2e8f9f7 44 {P0_1 , CAN_1, 1},
<> 144:ef7eb2e8f9f7 45 {P0_5 , CAN_2, 2},
<> 144:ef7eb2e8f9f7 46 {P0_22, CAN_1, 3},
<> 144:ef7eb2e8f9f7 47 {P2_8 , CAN_2, 1},
<> 144:ef7eb2e8f9f7 48 {NC , NC , 0}
<> 144:ef7eb2e8f9f7 49 };
<> 144:ef7eb2e8f9f7 50
<> 144:ef7eb2e8f9f7 51 // Type definition to hold a CAN message
<> 144:ef7eb2e8f9f7 52 struct CANMsg {
<> 144:ef7eb2e8f9f7 53 unsigned int reserved1 : 16;
<> 144:ef7eb2e8f9f7 54 unsigned int dlc : 4; // Bits 16..19: DLC - Data Length Counter
<> 144:ef7eb2e8f9f7 55 unsigned int reserved0 : 10;
<> 144:ef7eb2e8f9f7 56 unsigned int rtr : 1; // Bit 30: Set if this is a RTR message
<> 144:ef7eb2e8f9f7 57 unsigned int type : 1; // Bit 31: Set if this is a 29-bit ID message
<> 144:ef7eb2e8f9f7 58 unsigned int id; // CAN Message ID (11-bit or 29-bit)
<> 144:ef7eb2e8f9f7 59 unsigned char data[8]; // CAN Message Data Bytes 0-7
<> 144:ef7eb2e8f9f7 60 };
<> 144:ef7eb2e8f9f7 61 typedef struct CANMsg CANMsg;
<> 144:ef7eb2e8f9f7 62
<> 144:ef7eb2e8f9f7 63 static uint32_t can_disable(can_t *obj) {
<> 144:ef7eb2e8f9f7 64 uint32_t sm = obj->dev->MOD;
<> 144:ef7eb2e8f9f7 65 obj->dev->MOD |= 1;
<> 144:ef7eb2e8f9f7 66 return sm;
<> 144:ef7eb2e8f9f7 67 }
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 static inline void can_enable(can_t *obj) {
<> 144:ef7eb2e8f9f7 70 if (obj->dev->MOD & 1) {
<> 144:ef7eb2e8f9f7 71 obj->dev->MOD &= ~(1);
<> 144:ef7eb2e8f9f7 72 }
<> 144:ef7eb2e8f9f7 73 }
<> 144:ef7eb2e8f9f7 74
<> 144:ef7eb2e8f9f7 75 int can_mode(can_t *obj, CanMode mode) {
<> 144:ef7eb2e8f9f7 76 return 0; // not implemented
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t handle) {
<> 144:ef7eb2e8f9f7 80 return 0; // not implemented
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82
<> 144:ef7eb2e8f9f7 83 static int can_pclk(can_t *obj) {
<> 144:ef7eb2e8f9f7 84 int value = 0;
<> 144:ef7eb2e8f9f7 85 switch ((int)obj->dev) {
<> 144:ef7eb2e8f9f7 86 case CAN_1: value = (LPC_SC->PCLKSEL0 & (0x3 << 26)) >> 26; break;
<> 144:ef7eb2e8f9f7 87 case CAN_2: value = (LPC_SC->PCLKSEL0 & (0x3 << 28)) >> 28; break;
<> 144:ef7eb2e8f9f7 88 }
<> 144:ef7eb2e8f9f7 89
<> 144:ef7eb2e8f9f7 90 switch (value) {
<> 144:ef7eb2e8f9f7 91 case 1: return 1;
<> 144:ef7eb2e8f9f7 92 case 2: return 2;
<> 144:ef7eb2e8f9f7 93 case 3: return 6;
<> 144:ef7eb2e8f9f7 94 default: return 4;
<> 144:ef7eb2e8f9f7 95 }
<> 144:ef7eb2e8f9f7 96 }
<> 144:ef7eb2e8f9f7 97
<> 144:ef7eb2e8f9f7 98 // This table has the sampling points as close to 75% as possible. The first
<> 144:ef7eb2e8f9f7 99 // value is TSEG1, the second TSEG2.
<> 144:ef7eb2e8f9f7 100 static const int timing_pts[23][2] = {
<> 144:ef7eb2e8f9f7 101 {0x0, 0x0}, // 2, 50%
<> 144:ef7eb2e8f9f7 102 {0x1, 0x0}, // 3, 67%
<> 144:ef7eb2e8f9f7 103 {0x2, 0x0}, // 4, 75%
<> 144:ef7eb2e8f9f7 104 {0x3, 0x0}, // 5, 80%
<> 144:ef7eb2e8f9f7 105 {0x3, 0x1}, // 6, 67%
<> 144:ef7eb2e8f9f7 106 {0x4, 0x1}, // 7, 71%
<> 144:ef7eb2e8f9f7 107 {0x5, 0x1}, // 8, 75%
<> 144:ef7eb2e8f9f7 108 {0x6, 0x1}, // 9, 78%
<> 144:ef7eb2e8f9f7 109 {0x6, 0x2}, // 10, 70%
<> 144:ef7eb2e8f9f7 110 {0x7, 0x2}, // 11, 73%
<> 144:ef7eb2e8f9f7 111 {0x8, 0x2}, // 12, 75%
<> 144:ef7eb2e8f9f7 112 {0x9, 0x2}, // 13, 77%
<> 144:ef7eb2e8f9f7 113 {0x9, 0x3}, // 14, 71%
<> 144:ef7eb2e8f9f7 114 {0xA, 0x3}, // 15, 73%
<> 144:ef7eb2e8f9f7 115 {0xB, 0x3}, // 16, 75%
<> 144:ef7eb2e8f9f7 116 {0xC, 0x3}, // 17, 76%
<> 144:ef7eb2e8f9f7 117 {0xD, 0x3}, // 18, 78%
<> 144:ef7eb2e8f9f7 118 {0xD, 0x4}, // 19, 74%
<> 144:ef7eb2e8f9f7 119 {0xE, 0x4}, // 20, 75%
<> 144:ef7eb2e8f9f7 120 {0xF, 0x4}, // 21, 76%
<> 144:ef7eb2e8f9f7 121 {0xF, 0x5}, // 22, 73%
<> 144:ef7eb2e8f9f7 122 {0xF, 0x6}, // 23, 70%
<> 144:ef7eb2e8f9f7 123 {0xF, 0x7}, // 24, 67%
<> 144:ef7eb2e8f9f7 124 };
<> 144:ef7eb2e8f9f7 125
<> 144:ef7eb2e8f9f7 126 static unsigned int can_speed(unsigned int sclk, unsigned int pclk, unsigned int cclk, unsigned char psjw) {
<> 144:ef7eb2e8f9f7 127 uint32_t btr;
<> 144:ef7eb2e8f9f7 128 uint16_t brp = 0;
<> 144:ef7eb2e8f9f7 129 uint32_t calcbit;
<> 144:ef7eb2e8f9f7 130 uint32_t bitwidth;
<> 144:ef7eb2e8f9f7 131 int hit = 0;
<> 144:ef7eb2e8f9f7 132 int bits;
<> 144:ef7eb2e8f9f7 133
<> 144:ef7eb2e8f9f7 134 bitwidth = sclk / (pclk * cclk);
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 brp = bitwidth / 0x18;
<> 144:ef7eb2e8f9f7 137 while ((!hit) && (brp < bitwidth / 4)) {
<> 144:ef7eb2e8f9f7 138 brp++;
<> 144:ef7eb2e8f9f7 139 for (bits = 22; bits > 0; bits--) {
<> 144:ef7eb2e8f9f7 140 calcbit = (bits + 3) * (brp + 1);
<> 144:ef7eb2e8f9f7 141 if (calcbit == bitwidth) {
<> 144:ef7eb2e8f9f7 142 hit = 1;
<> 144:ef7eb2e8f9f7 143 break;
<> 144:ef7eb2e8f9f7 144 }
<> 144:ef7eb2e8f9f7 145 }
<> 144:ef7eb2e8f9f7 146 }
<> 144:ef7eb2e8f9f7 147
<> 144:ef7eb2e8f9f7 148 if (hit) {
<> 144:ef7eb2e8f9f7 149 btr = ((timing_pts[bits][1] << 20) & 0x00700000)
<> 144:ef7eb2e8f9f7 150 | ((timing_pts[bits][0] << 16) & 0x000F0000)
<> 144:ef7eb2e8f9f7 151 | ((psjw << 14) & 0x0000C000)
<> 144:ef7eb2e8f9f7 152 | ((brp << 0) & 0x000003FF);
<> 144:ef7eb2e8f9f7 153 } else {
<> 144:ef7eb2e8f9f7 154 btr = 0xFFFFFFFF;
<> 144:ef7eb2e8f9f7 155 }
<> 144:ef7eb2e8f9f7 156
<> 144:ef7eb2e8f9f7 157 return btr;
<> 144:ef7eb2e8f9f7 158 }
<> 144:ef7eb2e8f9f7 159
<> 144:ef7eb2e8f9f7 160 void can_init(can_t *obj, PinName rd, PinName td) {
<> 144:ef7eb2e8f9f7 161 CANName can_rd = (CANName)pinmap_peripheral(rd, PinMap_CAN_RD);
<> 144:ef7eb2e8f9f7 162 CANName can_td = (CANName)pinmap_peripheral(td, PinMap_CAN_TD);
<> 144:ef7eb2e8f9f7 163 obj->dev = (LPC_CAN_TypeDef *)pinmap_merge(can_rd, can_td);
<> 144:ef7eb2e8f9f7 164 MBED_ASSERT((int)obj->dev != NC);
<> 144:ef7eb2e8f9f7 165
<> 144:ef7eb2e8f9f7 166 switch ((int)obj->dev) {
<> 144:ef7eb2e8f9f7 167 case CAN_1: LPC_SC->PCONP |= 1 << 13; break;
<> 144:ef7eb2e8f9f7 168 case CAN_2: LPC_SC->PCONP |= 1 << 14; break;
<> 144:ef7eb2e8f9f7 169 }
<> 144:ef7eb2e8f9f7 170
<> 144:ef7eb2e8f9f7 171 pinmap_pinout(rd, PinMap_CAN_RD);
<> 144:ef7eb2e8f9f7 172 pinmap_pinout(td, PinMap_CAN_TD);
<> 144:ef7eb2e8f9f7 173
<> 144:ef7eb2e8f9f7 174 can_reset(obj);
<> 144:ef7eb2e8f9f7 175 obj->dev->IER = 0; // Disable Interrupts
<> 144:ef7eb2e8f9f7 176 can_frequency(obj, 100000);
<> 144:ef7eb2e8f9f7 177
<> 144:ef7eb2e8f9f7 178 LPC_CANAF->AFMR = ACCF_BYPASS; // Bypass Filter
<> 144:ef7eb2e8f9f7 179 }
<> 144:ef7eb2e8f9f7 180
<> 144:ef7eb2e8f9f7 181 void can_free(can_t *obj) {
<> 144:ef7eb2e8f9f7 182 switch ((int)obj->dev) {
<> 144:ef7eb2e8f9f7 183 case CAN_1: LPC_SC->PCONP &= ~(1 << 13); break;
<> 144:ef7eb2e8f9f7 184 case CAN_2: LPC_SC->PCONP &= ~(1 << 14); break;
<> 144:ef7eb2e8f9f7 185 }
<> 144:ef7eb2e8f9f7 186 }
<> 144:ef7eb2e8f9f7 187
<> 144:ef7eb2e8f9f7 188 int can_frequency(can_t *obj, int f) {
<> 144:ef7eb2e8f9f7 189 int pclk = can_pclk(obj);
<> 144:ef7eb2e8f9f7 190 int btr = can_speed(SystemCoreClock, pclk, (unsigned int)f, 1);
<> 144:ef7eb2e8f9f7 191
<> 144:ef7eb2e8f9f7 192 if (btr > 0) {
<> 144:ef7eb2e8f9f7 193 uint32_t modmask = can_disable(obj);
<> 144:ef7eb2e8f9f7 194 obj->dev->BTR = btr;
<> 144:ef7eb2e8f9f7 195 obj->dev->MOD = modmask;
<> 144:ef7eb2e8f9f7 196 return 1;
<> 144:ef7eb2e8f9f7 197 } else {
<> 144:ef7eb2e8f9f7 198 return 0;
<> 144:ef7eb2e8f9f7 199 }
<> 144:ef7eb2e8f9f7 200 }
<> 144:ef7eb2e8f9f7 201
<> 144:ef7eb2e8f9f7 202 int can_write(can_t *obj, CAN_Message msg, int cc) {
<> 144:ef7eb2e8f9f7 203 unsigned int CANStatus;
<> 144:ef7eb2e8f9f7 204 CANMsg m;
<> 144:ef7eb2e8f9f7 205
<> 144:ef7eb2e8f9f7 206 can_enable(obj);
<> 144:ef7eb2e8f9f7 207
<> 144:ef7eb2e8f9f7 208 m.id = msg.id ;
<> 144:ef7eb2e8f9f7 209 m.dlc = msg.len & 0xF;
<> 144:ef7eb2e8f9f7 210 m.rtr = msg.type;
<> 144:ef7eb2e8f9f7 211 m.type = msg.format;
<> 144:ef7eb2e8f9f7 212 memcpy(m.data, msg.data, msg.len);
<> 144:ef7eb2e8f9f7 213 const unsigned int *buf = (const unsigned int *)&m;
<> 144:ef7eb2e8f9f7 214
<> 144:ef7eb2e8f9f7 215 CANStatus = obj->dev->SR;
<> 144:ef7eb2e8f9f7 216 if (CANStatus & 0x00000004) {
<> 144:ef7eb2e8f9f7 217 obj->dev->TFI1 = buf[0] & 0xC00F0000;
<> 144:ef7eb2e8f9f7 218 obj->dev->TID1 = buf[1];
<> 144:ef7eb2e8f9f7 219 obj->dev->TDA1 = buf[2];
<> 144:ef7eb2e8f9f7 220 obj->dev->TDB1 = buf[3];
<> 144:ef7eb2e8f9f7 221 if (cc) {
<> 144:ef7eb2e8f9f7 222 obj->dev->CMR = 0x30;
<> 144:ef7eb2e8f9f7 223 } else {
<> 144:ef7eb2e8f9f7 224 obj->dev->CMR = 0x21;
<> 144:ef7eb2e8f9f7 225 }
<> 144:ef7eb2e8f9f7 226 return 1;
<> 144:ef7eb2e8f9f7 227
<> 144:ef7eb2e8f9f7 228 } else if (CANStatus & 0x00000400) {
<> 144:ef7eb2e8f9f7 229 obj->dev->TFI2 = buf[0] & 0xC00F0000;
<> 144:ef7eb2e8f9f7 230 obj->dev->TID2 = buf[1];
<> 144:ef7eb2e8f9f7 231 obj->dev->TDA2 = buf[2];
<> 144:ef7eb2e8f9f7 232 obj->dev->TDB2 = buf[3];
<> 144:ef7eb2e8f9f7 233 if (cc) {
<> 144:ef7eb2e8f9f7 234 obj->dev->CMR = 0x50;
<> 144:ef7eb2e8f9f7 235 } else {
<> 144:ef7eb2e8f9f7 236 obj->dev->CMR = 0x41;
<> 144:ef7eb2e8f9f7 237 }
<> 144:ef7eb2e8f9f7 238 return 1;
<> 144:ef7eb2e8f9f7 239
<> 144:ef7eb2e8f9f7 240 } else if (CANStatus & 0x00040000) {
<> 144:ef7eb2e8f9f7 241 obj->dev->TFI3 = buf[0] & 0xC00F0000;
<> 144:ef7eb2e8f9f7 242 obj->dev->TID3 = buf[1];
<> 144:ef7eb2e8f9f7 243 obj->dev->TDA3 = buf[2];
<> 144:ef7eb2e8f9f7 244 obj->dev->TDB3 = buf[3];
<> 144:ef7eb2e8f9f7 245 if (cc) {
<> 144:ef7eb2e8f9f7 246 obj->dev->CMR = 0x90;
<> 144:ef7eb2e8f9f7 247 } else {
<> 144:ef7eb2e8f9f7 248 obj->dev->CMR = 0x81;
<> 144:ef7eb2e8f9f7 249 }
<> 144:ef7eb2e8f9f7 250 return 1;
<> 144:ef7eb2e8f9f7 251 }
<> 144:ef7eb2e8f9f7 252
<> 144:ef7eb2e8f9f7 253 return 0;
<> 144:ef7eb2e8f9f7 254 }
<> 144:ef7eb2e8f9f7 255
<> 144:ef7eb2e8f9f7 256 int can_read(can_t *obj, CAN_Message *msg, int handle) {
<> 144:ef7eb2e8f9f7 257 CANMsg x;
<> 144:ef7eb2e8f9f7 258 unsigned int *i = (unsigned int *)&x;
<> 144:ef7eb2e8f9f7 259
<> 144:ef7eb2e8f9f7 260 can_enable(obj);
<> 144:ef7eb2e8f9f7 261
<> 144:ef7eb2e8f9f7 262 if (obj->dev->GSR & 0x1) {
<> 144:ef7eb2e8f9f7 263 *i++ = obj->dev->RFS; // Frame
<> 144:ef7eb2e8f9f7 264 *i++ = obj->dev->RID; // ID
<> 144:ef7eb2e8f9f7 265 *i++ = obj->dev->RDA; // Data A
<> 144:ef7eb2e8f9f7 266 *i++ = obj->dev->RDB; // Data B
<> 144:ef7eb2e8f9f7 267 obj->dev->CMR = 0x04; // release receive buffer
<> 144:ef7eb2e8f9f7 268
<> 144:ef7eb2e8f9f7 269 msg->id = x.id;
<> 144:ef7eb2e8f9f7 270 msg->len = x.dlc;
<> 144:ef7eb2e8f9f7 271 msg->format = (x.type)? CANExtended : CANStandard;
<> 144:ef7eb2e8f9f7 272 msg->type = (x.rtr)? CANRemote: CANData;
<> 144:ef7eb2e8f9f7 273 memcpy(msg->data,x.data,x.dlc);
<> 144:ef7eb2e8f9f7 274 return 1;
<> 144:ef7eb2e8f9f7 275 }
<> 144:ef7eb2e8f9f7 276
<> 144:ef7eb2e8f9f7 277 return 0;
<> 144:ef7eb2e8f9f7 278 }
<> 144:ef7eb2e8f9f7 279
<> 144:ef7eb2e8f9f7 280 void can_reset(can_t *obj) {
<> 144:ef7eb2e8f9f7 281 can_disable(obj);
<> 144:ef7eb2e8f9f7 282 obj->dev->GSR = 0; // Reset error counter when CAN1MOD is in reset
<> 144:ef7eb2e8f9f7 283 }
<> 144:ef7eb2e8f9f7 284
<> 144:ef7eb2e8f9f7 285 unsigned char can_rderror(can_t *obj) {
<> 144:ef7eb2e8f9f7 286 return (obj->dev->GSR >> 16) & 0xFF;
<> 144:ef7eb2e8f9f7 287 }
<> 144:ef7eb2e8f9f7 288
<> 144:ef7eb2e8f9f7 289 unsigned char can_tderror(can_t *obj) {
<> 144:ef7eb2e8f9f7 290 return (obj->dev->GSR >> 24) & 0xFF;
<> 144:ef7eb2e8f9f7 291 }
<> 144:ef7eb2e8f9f7 292
<> 144:ef7eb2e8f9f7 293 void can_monitor(can_t *obj, int silent) {
<> 144:ef7eb2e8f9f7 294 uint32_t mod_mask = can_disable(obj);
<> 144:ef7eb2e8f9f7 295 if (silent) {
<> 144:ef7eb2e8f9f7 296 obj->dev->MOD |= (1 << 1);
<> 144:ef7eb2e8f9f7 297 } else {
<> 144:ef7eb2e8f9f7 298 obj->dev->MOD &= ~(1 << 1);
<> 144:ef7eb2e8f9f7 299 }
<> 144:ef7eb2e8f9f7 300 if (!(mod_mask & 1)) {
<> 144:ef7eb2e8f9f7 301 can_enable(obj);
<> 144:ef7eb2e8f9f7 302 }
<> 144:ef7eb2e8f9f7 303 }