Zeroday Hong
mbed library sources. Supersedes mbed-src.
Fork of
mbed-dev
by 
mbed official
Diff: targets/TARGET_NXP/TARGET_LPC15XX/can_api.c
- Revision:
- 149:156823d33999
- Parent:
- 144:ef7eb2e8f9f7
- Child:
- 156:95d6b41a828b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NXP/TARGET_LPC15XX/can_api.c Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,487 @@
+/* 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 "mbed_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)
+
+#define CANCNTL_INIT (1 << 0) // Initialization
+#define CANCNTL_IE (1 << 1) // Module interrupt enable
+#define CANCNTL_SIE (1 << 2) // Status change interrupt enable
+#define CANCNTL_EIE (1 << 3) // Error interrupt enable
+#define CANCNTL_DAR (1 << 5) // Disable automatic retransmission
+#define CANCNTL_CCE (1 << 6) // Configuration change enable
+#define CANCNTL_TEST (1 << 7) // Test mode enable
+
+#define CANTEST_BASIC (1 << 2) // Basic mode
+#define CANTEST_SILENT (1 << 3) // Silent mode
+#define CANTEST_LBACK (1 << 4) // Loop back mode
+#define CANTEST_TX_MASK 0x0060 // Control of CAN_TXD pins
+#define CANTEST_TX_SHIFT 5
+#define CANTEST_RX (1 << 7) // Monitors the actual value of the CAN_RXD pin.
+
+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) {
+ int success = 0;
+ switch (mode) {
+ case MODE_RESET:
+ LPC_C_CAN0->CANCNTL &=~CANCNTL_TEST;
+ can_disable(obj);
+ success = 1;
+ break;
+ case MODE_NORMAL:
+ LPC_C_CAN0->CANCNTL &=~CANCNTL_TEST;
+ can_enable(obj);
+ success = 1;
+ break;
+ case MODE_SILENT:
+ LPC_C_CAN0->CANCNTL |= CANCNTL_TEST;
+ LPC_C_CAN0->CANTEST |= CANTEST_SILENT;
+ LPC_C_CAN0->CANTEST &=~ CANTEST_LBACK;
+ success = 1;
+ break;
+ case MODE_TEST_LOCAL:
+ LPC_C_CAN0->CANCNTL |= CANCNTL_TEST;
+ LPC_C_CAN0->CANTEST &=~CANTEST_SILENT;
+ LPC_C_CAN0->CANTEST |= CANTEST_LBACK;
+ success = 1;
+ break;
+ case MODE_TEST_SILENT:
+ LPC_C_CAN0->CANCNTL |= CANCNTL_TEST;
+ LPC_C_CAN0->CANTEST |= (CANTEST_LBACK | CANTEST_SILENT);
+ success = 1;
+ break;
+ case MODE_TEST_GLOBAL:
+ default:
+ success = 0;
+ break;
+ }
+
+ return success;
+}
+
+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);
+ }
+}