/* * This file is part of the libopenstm32 project. * * Copyright (C) 2010 Thomas Otto * Copyright (C) 2010 Piotr Esden-Tempski * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include #include #include struct can_tx_msg { u32 std_id; u32 ext_id; u8 ide; u8 rtr; u8 dlc; u8 data[8]; }; struct can_rx_msg { u32 std_id; u32 ext_id; u8 ide; u8 rtr; u8 dlc; u8 data[8]; u8 fmi; }; struct can_tx_msg can_tx_msg; struct can_rx_msg can_rx_msg; void gpio_setup(void) { /* Enable GPIOA clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN); /* Enable GPIOB clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN); gpio_set(GPIOA, GPIO6); /* LED0 off */ gpio_set(GPIOA, GPIO7); /* LED1 off */ gpio_set(GPIOB, GPIO0); /* LED2 off */ gpio_set(GPIOB, GPIO1); /* LED3 off */ /* Set GPIO6/7 (in GPIO port A) to 'output push-pull' for the LEDs. */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO6); gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO7); /* Set GPIO6/7 (in GPIO port B) to 'output push-pull' for the LEDs. */ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO0); gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO1); } void systick_setup() { /* 72MHz / 8 => 9000000 counts per second */ systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8); /* 9000000/9000 = 1000 overflows per second - every 1ms one interrupt */ systick_set_reload(9000); systick_interrupt_enable(); /* start counting */ systick_counter_enable(); } void can_setup() { u32 wait_ack = 0x00000000; u32 can_msr_inak_timeout = 0x000FFFFF; /* Enable peripheral clocks */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN); rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN); rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_CANEN); /* Configure CAN pin: RX (input pull-up) */ gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, GPIO_CAN_RX); gpio_set(GPIOA, GPIO_CAN_RX); /* Configure CAN pin: TX */ gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_CAN_TX); /* NVIC setup */ nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ); nvic_set_priority(NVIC_USB_LP_CAN_RX0_IRQ, 1); /* --- reset CAN periphery ------------------------------------------ */ rcc_peripheral_reset(&RCC_APB1RSTR, RCC_APB1RSTR_CANRST); rcc_peripheral_clear_reset(&RCC_APB1RSTR, RCC_APB1RSTR_CANRST); /* --- CAN cell init ------------------------------------------------ */ /* Exit from sleep mode */ CAN_MCR(CAN1) &= ~CAN_MCR_SLEEP; /* Request initialization "enter" */ CAN_MCR(CAN1) |= CAN_MCR_INRQ; /* Wait for acknowledge */ while ((wait_ack != can_msr_inak_timeout) && ((CAN_MSR(CAN1) & CAN_MSR_INAK) != CAN_MSR_INAK)) { wait_ack++; } /* Check the acknowledge */ if ((CAN_MSR(CAN1) & CAN_MSR_INAK) != CAN_MSR_INAK) { /* we should set some flag here or so because we failed */ gpio_clear(GPIOB, GPIO1); } else { /* set the automatic bus-off management */ CAN_MCR(CAN1) &= ~CAN_MCR_TTCM; CAN_MCR(CAN1) |= CAN_MCR_ABOM; CAN_MCR(CAN1) &= ~CAN_MCR_AWUM; CAN_MCR(CAN1) &= ~CAN_MCR_NART; CAN_MCR(CAN1) &= ~CAN_MCR_TXFP; /* Set bit timings */ CAN_BTR(CAN1) = 0x00000000 | CAN_BTR_SJW_1TQ | CAN_BTR_TS2_3TQ | CAN_BTR_TS2_4TQ | (u32)(CAN_BTR_BRP_MASK & 12); /* Request initialization "leave" */ CAN_MCR(CAN1) &= ~CAN_MCR_INRQ; /* Wait for acknowledge */ wait_ack = 0x00000000; while ((wait_ack != can_msr_inak_timeout) && ((CAN_MSR(CAN1) & CAN_MSR_INAK) == CAN_MSR_INAK)) { wait_ack++; } if ((CAN_MSR(CAN1) & CAN_MSR_INAK) == CAN_MSR_INAK) { /* set some flag here because we failed */ gpio_clear(GPIOB, GPIO1); } else { /* set some flag here because we succeeded */ gpio_set(GPIOB, GPIO1); } } /* --- CAN filter 0 init -------------------------------------------- */ u32 filter_select_bit = 0x00000001; /* Request initialization "enter" */ CAN_FMR(CAN1) |= CAN_FMR_FINIT; /* Deactivate the filter */ CAN_FA1R(CAN1) &= ~filter_select_bit; /* Set 32-bit scale for the filter */ CAN_FS1R(CAN1) |= filter_select_bit; /* Set the filter id to 0 */ CAN_FiR1(CAN1, 0) = 0x00000000; /* Set the filter id mask to 0 */ CAN_FiR2(CAN1, 0) = 0x00000000; /* Set filter mode to Id/Mask mode */ CAN_FM1R(CAN1) &= ~filter_select_bit; /* Select FIFO0 as filter assignement */ CAN_FFA1R(CAN1) &= ~filter_select_bit; /* Reactivate the filter */ CAN_FA1R(CAN1) |= filter_select_bit; /* Request initialization "leave" */ CAN_FMR(CAN1) &= ~CAN_FMR_FINIT; /* --- Enable CAN rx interrupt -------------------------------------- */ CAN_IER(CAN1) |= CAN_IER_FMPIE0; } void can_transmit(u32 id, u8 length, u8 data) { u32 mailbox = 0; if ((CAN_TSR(CAN1) & CAN_TSR_TME0) == CAN_TSR_TME0) { mailbox = CAN_MBOX0; gpio_set(GPIOB, GPIO0); } else if ((CAN_TSR(CAN1) & CAN_TSR_TME1) == CAN_TSR_TME1) { mailbox = CAN_MBOX1; gpio_set(GPIOB, GPIO0); } else if ((CAN_TSR(CAN1) & CAN_TSR_TME2) == CAN_TSR_TME2) { mailbox = CAN_MBOX2; gpio_set(GPIOB, GPIO0); } else { mailbox = 0; /* no mailbox */ gpio_clear(GPIOB, GPIO0); } if ( mailbox != 0 ) { /* check if we have an empty mailbox */ /* Set the ID */ CAN_TIxR(CAN1, mailbox) |= id << CAN_TIxR_STID_SHIFT; /* Set the DLC */ CAN_TDTxR(CAN1, mailbox) &= 0xFFFFFFFF0; CAN_TDTxR(CAN1, mailbox) |= length & CAN_TDTxR_DLC_MASK; /* Set the data */ CAN_TDLxR(CAN1, mailbox) = data; CAN_TDHxR(CAN1, mailbox) = 0x00000000; /* Request transmission */ CAN_TIxR(CAN1, mailbox) |= CAN_TIxR_TXRQ; } } void sys_tick_handler() { static int temp32 = 0; temp32++; /* we call this handler every 1ms so 1000ms = 1s on/off */ if (temp32 == 1000) { gpio_toggle(GPIOA, GPIO6); /* LED2 on/off */ temp32 = 0; /* --- Transmit CAN frame ----------------------------------- */ can_transmit(0, 0, 10); } } void usb_lp_can_rx0_isr(void) { gpio_toggle(GPIOA, GPIO7); CAN_RF0R(CAN1) |= CAN_RF0R_RFOM0; } int main(void) { rcc_clock_setup_in_hse_8mhz_out_72mhz(); gpio_setup(); can_setup(); systick_setup(); while(1); /* Halt. */ return 0; }