mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
Diff: targets/hal/TARGET_NXP/TARGET_LPC15XX/can_api.c
- Revision:
- 245:b4dea936db71
- Child:
- 250:a49055e7a707
diff -r 7618f037e2de -r b4dea936db71 targets/hal/TARGET_NXP/TARGET_LPC15XX/can_api.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_NXP/TARGET_LPC15XX/can_api.c Mon Jun 30 08:00:09 2014 +0100 @@ -0,0 +1,437 @@ +/* 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 + +#define CANIFn_ARB2_DIR (1UL << 13) +#define CANIFn_ARB2_XTD (1UL << 14) +#define CANIFn_ARB2_MSGVAL (1UL << 15) +#define CANIFn_MSK2_MXTD (1UL << 15) +#define CANIFn_MSK2_MDIR (1UL << 14) +#define CANIFn_MCTRL_EOB (1UL << 7) +#define CANIFn_MCTRL_TXRQST (1UL << 8) +#define CANIFn_MCTRL_RMTEN (1UL << 9) +#define CANIFn_MCTRL_RXIE (1UL << 10) +#define CANIFn_MCTRL_TXIE (1UL << 11) +#define CANIFn_MCTRL_UMASK (1UL << 12) +#define CANIFn_MCTRL_INTPND (1UL << 13) +#define CANIFn_MCTRL_MSGLST (1UL << 14) +#define CANIFn_MCTRL_NEWDAT (1UL << 15) +#define CANIFn_CMDMSK_DATA_B (1UL << 0) +#define CANIFn_CMDMSK_DATA_A (1UL << 1) +#define CANIFn_CMDMSK_TXRQST (1UL << 2) +#define CANIFn_CMDMSK_NEWDAT (1UL << 2) +#define CANIFn_CMDMSK_CLRINTPND (1UL << 3) +#define CANIFn_CMDMSK_CTRL (1UL << 4) +#define CANIFn_CMDMSK_ARB (1UL << 5) +#define CANIFn_CMDMSK_MASK (1UL << 6) +#define CANIFn_CMDMSK_WR (1UL << 7) +#define CANIFn_CMDMSK_RD (0UL << 7) +#define CANIFn_CMDREQ_BUSY (1UL << 15) + +static uint32_t can_irq_id = 0; +static can_irq_handler irq_handler; + +static inline void can_disable(can_t *obj) { + LPC_C_CAN0->CANCNTL |= 0x1; +} + +static inline void can_enable(can_t *obj) { + if (LPC_C_CAN0->CANCNTL & 0x1) { + LPC_C_CAN0->CANCNTL &= ~(0x1); + } +} + +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_C_CAN0->CANMSGV1 | (LPC_C_CAN0->CANMSGV2 << 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_C_CAN0->CANIF1_ARB1 = (id & 0xFFFF); + LPC_C_CAN0->CANIF1_ARB2 = CANIFn_ARB2_MSGVAL | CANIFn_ARB2_XTD | ((id >> 16) & 0x1FFF); + LPC_C_CAN0->CANIF1_MSK1 = (mask & 0xFFFF); + LPC_C_CAN0->CANIF1_MSK2 = CANIFn_MSK2_MXTD /*| CANIFn_MSK2_MDIR*/ | ((mask >> 16) & 0x1FFF); + } else { + // Mark message valid, Direction = TX, Set Identifier and mask everything + LPC_C_CAN0->CANIF1_ARB2 = CANIFn_ARB2_MSGVAL | ((id << 2) & 0x1FFF); + LPC_C_CAN0->CANIF1_MSK2 = /*CANIFn_MSK2_MDIR |*/ ((mask << 2) & 0x1FFF); + } + + // Use mask, single message object and set DLC + LPC_C_CAN0->CANIF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_EOB | CANIFn_MCTRL_RXIE | (DLC_MAX & 0xF); + + // Transfer all fields to message object + LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_MASK | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL; + + // Start Transfer to given message number + LPC_C_CAN0->CANIF1_CMDREQ = (handle & 0x3F); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while ( LPC_C_CAN0->CANIF1_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_C_CAN0->CANCNTL &= ~(1UL << 1); // Disable Interrupts :) + can_irq_id = 0; + NVIC_DisableIRQ(C_CAN0_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_C_CAN0->CANCNTL &= ~(1UL << 1 | 1UL << 2); + } else { + LPC_C_CAN0->CANCNTL |= 1UL << 1 | 1UL << 2; + } + // Take it out of reset... + can_enable(obj); + + // Enable NVIC if at least 1 interrupt is active + NVIC_SetVector(C_CAN0_IRQn, (uint32_t) &can_irq); + NVIC_EnableIRQ(C_CAN0_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; + } + } + } + + clkdiv = clkdiv - 1; + + if (hit) { + btr = (timing_pts[bits][1] & 0x7) << 12 + | (timing_pts[bits][0] & 0xf) << 8 + | (psjw & 0x3) << 6 + | (brp & 0x3F); + 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_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + + // Mark message valid, Direction = RX, Don't care about anything else + LPC_C_CAN0->CANIF1_ARB1 = 0; + LPC_C_CAN0->CANIF1_ARB2 = 0; + LPC_C_CAN0->CANIF1_MCTRL = 0; + + for ( i = 0; i < MSG_OBJ_MAX; i++ ) { + // Transfer arb and control fields to message object + LPC_C_CAN0->CANIF1_CMDMSK_W = CANIFn_CMDMSK_WR | CANIFn_CMDMSK_ARB | CANIFn_CMDMSK_CTRL | CANIFn_CMDMSK_TXRQST; + + // Start Transfer to given message number + LPC_C_CAN0->CANIF1_CMDREQ = (i & 0x3F); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while ( LPC_C_CAN0->CANIF1_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->SYSAHBCLKCTRL1 |= (1UL << 7); + LPC_SYSCON->PRESETCTRL1 |= (1UL << 7); + LPC_SYSCON->PRESETCTRL1 &= ~(1UL << 7); + + // Enable Initialization mode + if (!(LPC_C_CAN0->CANCNTL & (1UL << 0))) { + LPC_C_CAN0->CANCNTL |= (1UL << 0); + } + + LPC_SWM->PINASSIGN[6] &= ~(0x00FFFF00L); + LPC_SWM->PINASSIGN[6] |= (rd << 16) | (td << 8); + + can_frequency(obj, 100000); + + // Resume operation + LPC_C_CAN0->CANCNTL &= ~(1UL << 0); + while ( LPC_C_CAN0->CANCNTL & (1UL << 0) ); + + // Initialize RX message object + can_config_rxmsgobj(obj); +} + +void can_free(can_t *obj) { + LPC_SYSCON->SYSAHBCLKCTRL1 &= ~(1UL << 7); + LPC_SYSCON->PRESETCTRL1 &= ~(1UL << 7); +} + +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_C_CAN0->CANCNTL |= (1UL << 6 | 1UL << 0); // set CCE and INIT + LPC_C_CAN0->CANCLKDIV = clkdiv; + LPC_C_CAN0->CANBT = btr; + LPC_C_CAN0->CANBRPE = 0x0000; + LPC_C_CAN0->CANCNTL &= ~(1UL << 6 | 1UL << 0); // clear CCE and INIT + 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_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY ); + + // Set the direction bit based on the message type + uint32_t direction = 0; + if (msg.type == CANData) { + direction = CANIFn_ARB2_DIR; + } + + if (msg.format == CANExtended) { + // Mark message valid, Extended Frame, Set Identifier and mask everything + LPC_C_CAN0->CANIF1_ARB1 = (msg.id & 0xFFFF); + LPC_C_CAN0->CANIF1_ARB2 = CANIFn_ARB2_MSGVAL | CANIFn_ARB2_XTD | direction | ((msg.id >> 16) & 0x1FFFF); + LPC_C_CAN0->CANIF1_MSK1 = (ID_EXT_MASK & 0xFFFF); + LPC_C_CAN0->CANIF1_MSK2 = CANIFn_MSK2_MXTD | CANIFn_MSK2_MDIR | ((ID_EXT_MASK >> 16) & 0x1FFF); + } else { + // Mark message valid, Set Identifier and mask everything + LPC_C_CAN0->CANIF1_ARB2 = CANIFn_ARB2_MSGVAL | direction | ((msg.id << 2) & 0x1FFF); + LPC_C_CAN0->CANIF1_MSK2 = CANIFn_MSK2_MDIR | ((ID_STD_MASK << 2) & 0x1FFF); + } + + // Use mask, request transmission, single message object and set DLC + LPC_C_CAN0->CANIF1_MCTRL = CANIFn_MCTRL_UMASK | CANIFn_MCTRL_TXRQST | CANIFn_MCTRL_EOB | (msg.len & 0xF); + + LPC_C_CAN0->CANIF1_DA1 = ((msg.data[1] & 0xFF) << 8) | (msg.data[0] & 0xFF); + LPC_C_CAN0->CANIF1_DA2 = ((msg.data[3] & 0xFF) << 8) | (msg.data[2] & 0xFF); + LPC_C_CAN0->CANIF1_DB1 = ((msg.data[5] & 0xFF) << 8) | (msg.data[4] & 0xFF); + LPC_C_CAN0->CANIF1_DB2 = ((msg.data[7] & 0xFF) << 8) | (msg.data[6] & 0xFF); + + // Transfer all fields to message object + LPC_C_CAN0->CANIF1_CMDMSK_W = 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_C_CAN0->CANIF1_CMDREQ = (msgnum & 0x3F); + + // Wait until transfer to message ram complete - TODO: maybe not block?? + while ( LPC_C_CAN0->CANIF1_CMDREQ & CANIFn_CMDREQ_BUSY); + + // Wait until TXOK is set, then clear it - TODO: maybe not block + //while ( !(LPC_C_CAN0->STAT & CANSTAT_TXOK) ); + LPC_C_CAN0->CANSTAT &= ~(1UL << 3); + + 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_C_CAN0->CANND1 | (LPC_C_CAN0->CANND2 << 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_C_CAN0->CANIF2_CMDREQ & CANIFn_CMDREQ_BUSY ); + + // Transfer all fields to message object + LPC_C_CAN0->CANIF2_CMDMSK_W = 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_C_CAN0->CANIF2_CMDREQ = (handle & 0x3F); + + // Wait until transfer to message ram complete + while ( LPC_C_CAN0->CANIF2_CMDREQ & CANIFn_CMDREQ_BUSY ); + + if (LPC_C_CAN0->CANIF2_ARB2 & CANIFn_ARB2_XTD) { + msg->format = CANExtended; + msg->id = (LPC_C_CAN0->CANIF2_ARB1 & 0x1FFF) << 16; + msg->id |= (LPC_C_CAN0->CANIF2_ARB2 & 0x1FFF); + } else { + msg->format = CANStandard; + msg->id = (LPC_C_CAN0->CANIF2_ARB2 & 0x1FFF) >> 2; + } + + if (LPC_C_CAN0->CANIF2_ARB2 & CANIFn_ARB2_DIR) { + msg->type = CANRemote; + } + else { + msg->type = CANData; + } + + msg->len = (LPC_C_CAN0->CANIF2_MCTRL & 0xF); // TODO: If > 8, len = 8 + msg->data[0] = ((LPC_C_CAN0->CANIF2_DA1 >> 0) & 0xFF); + msg->data[1] = ((LPC_C_CAN0->CANIF2_DA1 >> 8) & 0xFF); + msg->data[2] = ((LPC_C_CAN0->CANIF2_DA2 >> 0) & 0xFF); + msg->data[3] = ((LPC_C_CAN0->CANIF2_DA2 >> 8) & 0xFF); + msg->data[4] = ((LPC_C_CAN0->CANIF2_DB1 >> 0) & 0xFF); + msg->data[5] = ((LPC_C_CAN0->CANIF2_DB1 >> 8) & 0xFF); + msg->data[6] = ((LPC_C_CAN0->CANIF2_DB2 >> 0) & 0xFF); + msg->data[7] = ((LPC_C_CAN0->CANIF2_DB2 >> 8) & 0xFF); + + LPC_C_CAN0->CANSTAT &= ~(1UL << 4); + return 1; + } + return 0; +} + +void can_reset(can_t *obj) { + LPC_SYSCON->PRESETCTRL1 &= ~(1UL << 7); + LPC_C_CAN0->CANSTAT = 0; + can_config_rxmsgobj(obj); +} + +unsigned char can_rderror(can_t *obj) { + return ((LPC_C_CAN0->CANEC >> 8) & 0x7F); +} + +unsigned char can_tderror(can_t *obj) { + return (LPC_C_CAN0->CANEC & 0xFF); +} + +void can_monitor(can_t *obj, int silent) { + if (silent) { + LPC_C_CAN0->CANCNTL |= (1UL << 7); + LPC_C_CAN0->CANTEST |= (1UL << 3); + } else { + LPC_C_CAN0->CANCNTL &= ~(1UL << 7); + LPC_C_CAN0->CANTEST &= ~(1UL << 3); + } + + if (!(LPC_C_CAN0->CANCNTL & (1UL << 0))) { + LPC_C_CAN0->CANCNTL |= (1UL << 0); + } +}