mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
Diff: targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/TARGET_LPC11CXX/can_api.c
- Revision:
- 41:e8b66477f5bf
- Child:
- 203:0f54f988aa69
diff -r 5fa4b7c54c1d -r e8b66477f5bf targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/TARGET_LPC11CXX/can_api.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/TARGET_LPC11CXX/can_api.c Fri Oct 25 15:00:04 2013 +0100 @@ -0,0 +1,411 @@ +/* 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 "can_api.h" + +#include "cmsis.h" +#include "error.h" + +#include <math.h> +#include <string.h> + +/* Handy defines */ +#define MSG_OBJ_MAX 32 +#define DLC_MAX 8 + +#define ID_STD_MASK 0x07FF +#define ID_EXT_MASK 0x1FFFFFFF +#define DLC_MASK 0x0F + +static uint32_t can_irq_id = 0; +static can_irq_handler irq_handler; + +static uint32_t can_disable(can_t *obj) { + uint32_t sm = LPC_CAN->CNTL; + LPC_CAN->CNTL |= CANCNTL_INIT; + return sm; +} + +static inline void can_enable(can_t *obj) { + if (LPC_CAN->CNTL & CANCNTL_INIT) { + LPC_CAN->CNTL &= ~CANCNTL_INIT; + } +} + +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) { + uint16_t i; + + // Find first free message object + if(handle == 0) { + uint32_t msgval = LPC_CAN->MSGV1 | (LPC_CAN->MSGV2 << 16); + // Find first free messagebox + for(i = 0; i < 32; i++) { + if((msgval & (1 << i)) == 0) { + handle = i+1; + break; + } + } + } + + if(handle > 0 && handle < 32) { + if(format == CANExtended) { + // Mark message valid, Direction = TX, Extended Frame, Set Identifier and mask everything + LPC_CAN->IF1_ARB1 = BFN_PREP(id, CANIFn_ARB1_ID); + LPC_CAN->IF1_ARB2 = CANIFn_ARB2_MSGVAL | CANIFn_ARB2_XTD | BFN_PREP(id >> 16, CANIFn_ARB2_ID); + LPC_CAN->IF1_MSK1 = BFN_PREP(mask, CANIFn_MSK1_MSK); + LPC_CAN->IF1_MSK2 = CANIFn_MSK2_MXTD | CANIFn_MSK2_MDIR | BFN_PREP(mask >> 16, CANIFn_MSK2_MSK); + } + else { + // Mark message valid, Direction = TX, Set Identifier and mask everything + LPC_CAN->IF1_ARB2 = CANIFn_ARB2_MSGVAL | BFN_PREP(id << 2, CANIFn_ARB2_ID); + LPC_CAN->IF1_MSK2 = CANIFn_MSK2_MDIR | BFN_PREP(mask << 2, CANIFn_MSK2_MSK); + } + + // Use mask, single message object and set DLC + LPC_CAN->IF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_EOB | CANIFn_MCTRL_RXIE | BFN_PREP(DLC_MAX, CANIFn_MCTRL_DLC); + + // Transfer all fields to message object + LPC_CAN->IF1_CMDMSK = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_MASK | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL; + + // Start Transfer to given message number + LPC_CAN->IF1_CMDREQ = BFN_PREP(handle, CANIFn_CMDREQ_MN); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while( LPC_CAN->IF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + } + + return handle; +} + +static inline void can_irq() { + irq_handler(can_irq_id, IRQ_RX); +} + +// Register CAN object's irq handler +void can_irq_init(can_t *obj, can_irq_handler handler, uint32_t id) { + irq_handler = handler; + can_irq_id = id; +} + +// Unregister CAN object's irq handler +void can_irq_free(can_t *obj) { + LPC_CAN->CNTL &= ~CANCNTL_IE; // Disable Interrupts :) + + can_irq_id = 0; + NVIC_DisableIRQ(CAN_IRQn); +} + +// Clear or set a irq +void can_irq_set(can_t *obj, CanIrqType type, uint32_t enable) { + // Put CAN in Reset Mode and enable interrupt + can_disable(obj); + if(enable == 0) { + LPC_CAN->CNTL &= ~(CANCNTL_IE | CANCNTL_SIE); + } + else { + LPC_CAN->CNTL |= CANCNTL_IE | CANCNTL_SIE; + } + // Take it out of reset... + can_enable(obj); + + // Enable NVIC if at least 1 interrupt is active + NVIC_SetVector(CAN_IRQn, (uint32_t) &can_irq); + NVIC_EnableIRQ(CAN_IRQn); +} + +// 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 cclk, unsigned char psjw) { + uint32_t btr; + uint32_t clkdiv = 1; + uint16_t brp = 0; + uint32_t calcbit; + uint32_t bitwidth; + int hit = 0; + int bits = 0; + + bitwidth = sclk / 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; + } + } + } + + /* This might be funky + while(btr > 63 && clkdiv < 16) { + btr = btr / 2; + clkdiv = clkdiv * 2; + } + */ + clkdiv = clkdiv - 1; + + if (hit) { + btr = BFN_PREP(timing_pts[bits][1], CANBT_TSEG2) + | BFN_PREP(timing_pts[bits][0], CANBT_TSEG1) + | BFN_PREP(psjw, CANBT_SJW) + | BFN_PREP(brp, CANBT_BRP); + btr = btr | (clkdiv << 16); + + } else { + btr = 0; + } + + return btr; +} + + +int can_config_rxmsgobj(can_t *obj) { + uint16_t i = 0; + + // Make sure the interface is available + //while( LPC_CAN->IF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + + // Mark message valid, Direction = RX, Don't care about anything else + LPC_CAN->IF1_ARB1 = 0; + LPC_CAN->IF1_ARB2 = 0; + LPC_CAN->IF1_MCTRL = 0; + + for ( i = 0; i < MSG_OBJ_MAX; i++ ) + { + // Transfer arb and control fields to message object + LPC_CAN->IF1_CMDMSK = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL | CANIFn_CMDMSK_TXRQST; + + // Start Transfer to given message number + LPC_CAN->IF1_CMDREQ = BFN_PREP(i, CANIFn_CMDREQ_MN); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while( LPC_CAN->IF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + } + + // Accept all messages + can_filter(obj, 0, 0, CANStandard, 1); + + return 1; +} + + +void can_init(can_t *obj, PinName rd, PinName td) { + // Enable power and clock + LPC_SYSCON->PRESETCTRL |= PRESETCTRL_CAN_RST_N; + LPC_SYSCON->SYSAHBCLKCTRL |= SYSAHBCLKCTRL_CAN; + + // Enable Initialization mode + if (!(LPC_CAN->CNTL & CANCNTL_INIT)) { + LPC_CAN->CNTL |= CANCNTL_INIT; + } + + can_frequency(obj, 125000); + + // Resume operation + LPC_CAN->CNTL &= ~CANCNTL_INIT; + while ( LPC_CAN->CNTL & CANCNTL_INIT ); + + // Initialize RX message object + can_config_rxmsgobj(obj); +} + +void can_free(can_t *obj) { + LPC_SYSCON->SYSAHBCLKCTRL &= ~(SYSAHBCLKCTRL_CAN); + LPC_SYSCON->PRESETCTRL &= ~(PRESETCTRL_CAN_RST_N); +} + +int can_frequency(can_t *obj, int f) { + int btr = can_speed(SystemCoreClock, (unsigned int)f, 1); + int clkdiv = (btr >> 16) & 0x0F; + btr = btr & 0xFFFF; + + if (btr > 0) { + // Set the bit clock + LPC_CAN->CNTL |= CANCNTL_CCE; + LPC_CAN->CLKDIV = clkdiv; + LPC_CAN->BT = btr; + LPC_CAN->BRPE = 0x0000; + LPC_CAN->CNTL &= ~CANCNTL_CCE; + return 1; + } + return 0; +} + +int can_write(can_t *obj, CAN_Message msg, int cc) { + uint16_t msgnum = 0; + + // Make sure controller is enabled + can_enable(obj); + + // Make sure the interface is available + while( LPC_CAN->IF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + + if(msg.format == CANExtended) { + // Mark message valid, Direction = TX, Extended Frame, Set Identifier and mask everything + LPC_CAN->IF1_ARB1 = BFN_PREP(msg.id, CANIFn_ARB1_ID); + LPC_CAN->IF1_ARB2 = CANIFn_ARB2_MSGVAL | CANIFn_ARB2_XTD | CANIFn_ARB2_DIR | BFN_PREP(msg.id >> 16, CANIFn_ARB2_ID); + LPC_CAN->IF1_MSK1 = BFN_PREP(ID_EXT_MASK, CANIFn_MSK1_MSK); + LPC_CAN->IF1_MSK2 = CANIFn_MSK2_MXTD | CANIFn_MSK2_MDIR | BFN_PREP(ID_EXT_MASK >> 16, CANIFn_MSK2_MSK); + } + else { + // Mark message valid, Direction = TX, Set Identifier and mask everything + LPC_CAN->IF1_ARB2 = CANIFn_ARB2_MSGVAL | CANIFn_ARB2_DIR | BFN_PREP(msg.id << 2, CANIFn_ARB2_ID); + LPC_CAN->IF1_MSK2 = CANIFn_MSK2_MDIR | BFN_PREP(ID_STD_MASK << 2, CANIFn_MSK2_MSK); + } + + // Use mask, request transmission, single message object and set DLC + LPC_CAN->IF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_TXRQST | CANIFn_MCTRL_EOB | BFN_PREP(msg.len, CANIFn_MCTRL_DLC); + + LPC_CAN->IF1_DA1 = BFN_PREP(msg.data[1], CANIFn_DA1_DATA1) | BFN_PREP(msg.data[0], CANIFn_DA1_DATA0); + LPC_CAN->IF1_DA2 = BFN_PREP(msg.data[3], CANIFn_DA2_DATA3) | BFN_PREP(msg.data[2], CANIFn_DA2_DATA2); + LPC_CAN->IF1_DB1 = BFN_PREP(msg.data[5], CANIFn_DB1_DATA5) | BFN_PREP(msg.data[4], CANIFn_DB1_DATA4); + LPC_CAN->IF1_DB2 = BFN_PREP(msg.data[7], CANIFn_DB2_DATA7) | BFN_PREP(msg.data[6], CANIFn_DB2_DATA6); + + // Transfer all fields to message object + LPC_CAN->IF1_CMDMSK = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_MASK | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL | CANIFn_CMDMSK_TXRQST | CANIFn_CMDMSK_DATA_A | CANIFn_CMDMSK_DATA_B; + + // Start Transfer to given message number + LPC_CAN->IF1_CMDREQ = BFN_PREP(msgnum, CANIFn_CMDREQ_MN); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while( LPC_CAN->IF1_CMDREQ & CANIFn_CMDREQ_BUSY); + + // Wait until TXOK is set, then clear it - TODO: maybe not block + //while( !(LPC_CAN->STAT & CANSTAT_TXOK) ); + LPC_CAN->STAT &= ~(CANSTAT_TXOK); + + return 1; +} + +int can_read(can_t *obj, CAN_Message *msg, int handle) { + uint16_t i; + + // Make sure controller is enabled + can_enable(obj); + + // Find first message object with new data + if(handle == 0) { + uint32_t newdata = LPC_CAN->ND1 | (LPC_CAN->ND2 << 16); + // Find first free messagebox + for(i = 0; i < 32; i++) { + if(newdata & (1 << i)) { + handle = i+1; + break; + } + } + } + + if(handle > 0 && handle < 32) { + // Wait until message interface is free + while( LPC_CAN->IF2_CMDREQ & CANIFn_CMDREQ_BUSY ); + + // Transfer all fields to message object + LPC_CAN->IF2_CMDMSK = CANIFn_CMDMSK_RD | CANIFn_CMDMSK_MASK | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL | CANIFn_CMDMSK_CLRINTPND | CANIFn_CMDMSK_TXRQST | CANIFn_CMDMSK_DATA_A | CANIFn_CMDMSK_DATA_B; + + // Start Transfer from given message number + LPC_CAN->IF2_CMDREQ = BFN_PREP(handle, CANIFn_CMDREQ_MN); + + // Wait until transfer to message ram complete + while( LPC_CAN->IF2_CMDREQ & CANIFn_CMDREQ_BUSY ); + + if (LPC_CAN->IF2_ARB2 & CANIFn_ARB2_XTD) { + msg->format = CANExtended; + msg->id = (LPC_CAN->IF2_ARB1 & CANIFn_ARB2_ID_MASK) << 16; + msg->id |= (LPC_CAN->IF2_ARB2 & CANIFn_ARB2_ID_MASK); + } + else { + msg->format = CANStandard; + msg->id = (LPC_CAN->IF2_ARB2 & CANIFn_ARB2_ID_MASK) >> 2; + } + + // TODO: Remote frame support + msg->type = CANData; + msg->len = BFN_GET(LPC_CAN->IF2_MCTRL, CANIFn_MCTRL_DLC); // TODO: If > 8, len = 8 + msg->data[0] = BFN_GET(LPC_CAN->IF2_DA1, CANIFn_DA1_DATA0); + msg->data[1] = BFN_GET(LPC_CAN->IF2_DA1, CANIFn_DA1_DATA1); + msg->data[2] = BFN_GET(LPC_CAN->IF2_DA2, CANIFn_DA2_DATA2); + msg->data[3] = BFN_GET(LPC_CAN->IF2_DA2, CANIFn_DA2_DATA3); + msg->data[4] = BFN_GET(LPC_CAN->IF2_DB1, CANIFn_DB1_DATA4); + msg->data[5] = BFN_GET(LPC_CAN->IF2_DB1, CANIFn_DB1_DATA5); + msg->data[6] = BFN_GET(LPC_CAN->IF2_DB2, CANIFn_DB2_DATA6); + msg->data[7] = BFN_GET(LPC_CAN->IF2_DB2, CANIFn_DB2_DATA7); + + LPC_CAN->STAT &= ~(CANSTAT_RXOK); + return 1; + } + + return 0; +} + +void can_reset(can_t *obj) { + LPC_SYSCON->PRESETCTRL &= ~PRESETCTRL_CAN_RST_N; + LPC_CAN->STAT = 0; + + can_config_rxmsgobj(obj); +} + +unsigned char can_rderror(can_t *obj) { + return BFN_GET(LPC_CAN->EC, CANEC_REC); +} + +unsigned char can_tderror(can_t *obj) { + return BFN_GET(LPC_CAN->EC, CANEC_TEC); +} + +void can_monitor(can_t *obj, int silent) { + if (silent) { + LPC_CAN->CNTL |= CANCNTL_TEST; + LPC_CAN->TEST |= CANTEST_SILENT; + } else { + LPC_CAN->CNTL &= ~(CANCNTL_TEST); + LPC_CAN->TEST &= ~CANTEST_SILENT; + } + + if (!(LPC_CAN->CNTL & CANCNTL_INIT)) { + LPC_CAN->CNTL |= CANCNTL_INIT; + } +}