/* * Copyright (C) 2019 Gunar Schorcht * * This file is subject to the terms and conditions of the GNU Lesser * General Public License v2.1. See the file LICENSE in the top level * directory for more details. */ /** * @ingroup cpu_esp32 * @brief Implementation of the CAN controller driver for ESP32 (esp_can) * * @author Gunar Schorcht * @file * @{ */ #include #include #include #include "can_esp.h" #include "can_params.h" #include "esp_attr.h" #include "gpio_arch.h" #include "irq_arch.h" #include "driver/periph_ctrl.h" #include "esp_rom_gpio.h" #include "hal/interrupt_controller_types.h" #include "hal/interrupt_controller_ll.h" #include "hal/twai_hal.h" #include "log.h" #include "rom/ets_sys.h" #include "soc/gpio_sig_map.h" #define ENABLE_DEBUG 0 #include "debug.h" #define CAN TWAI /** Common ESP CAN definitions */ #define ESP_CAN_INTR_MASK (0xffU) /* interrupts handled by ESP CAN */ #define ESP_CAN_CLOCK APB_CLK_FREQ /* controller main clock */ /** Error mode limits used for ESP CAN */ #define ESP_CAN_ERROR_WARNING_LIMIT 96 /* indicator for heavy loaded bus */ #define ESP_CAN_ERROR_PASSIVE_LIMIT 128 /* switch to error passive state */ #define ESP_CAN_ERROR_BUS_OFF_LIMIT 256 /* switch to bus off state */ /* ESP32 CAN events */ #define ESP_CAN_EVENT_BUS_OFF (1 << 0) #define ESP_CAN_EVENT_ERROR_WARNING (1 << 1) #define ESP_CAN_EVENT_ERROR_PASSIVE (1 << 2) #define ESP_CAN_EVENT_TX_ERROR (1 << 3) #define ESP_CAN_EVENT_RX_ERROR (1 << 4) #define ESP_CAN_EVENT_TX_CONFIRMATION (1 << 5) #define ESP_CAN_EVENT_RX_INDICATION (1 << 6) #define ESP_CAN_EVENT_ARBITRATION_LOST (1 << 7) #define ESP_CAN_EVENT_WAKE_UP (1 << 8) /* ESP32 CAN commands */ #define ESP_CMD_TX_REQ 0x01 /* Transmission Request */ #define ESP_CMD_ABORT_TX 0x02 /* Abort Transmission */ #define ESP_CMD_TX_SINGLE_SHOT 0x03 /* Single Shot Transmission */ #define ESP_CMD_RELEASE_RX_BUFF 0x04 /* Release Receive Buffer */ #define ESP_CMD_CLR_DATA_OVRN 0x08 /* Clear Data Overrun */ #define ESP_CMD_SELF_RX_REQ 0x10 /* Self Reception Request */ #define ESP_CMD_SELF_RX_SINGLE_SHOT 0x12 /* Single Shot Self Reception */ /** * Frame format definition as it is expected/received in the TX/RX buffer * of ESP32. */ #define ESP_CAN_SFF_ID_LEN 2 /* two byte (11 bit) in SFF ID format */ #define ESP_CAN_EFF_ID_LEN 4 /* two byte (29 bit) in EFF ID format */ #define ESP_CAN_MAX_DATA_LEN 8 /* 8 data bytes at maximum */ #define ESP_CAN_FRAME_LEN 13 /* 13 bytes at maximum */ #if !defined(CAN_CLK_OUT) && !defined(CAN_CLK_OUT_DIV) /* if CAN_CLK_OUT is not used, CAN_CLKOUT_DIV is set to 0 */ #define CAN_CLK_OUT_DIV 0 #elif defined(CAN_CLK_OUT) && !defined(CAN_CLK_OUT_DIV) /* if CAN_CLK_OUT is used, CAN_CLK_OUT_DIV has to be defined */ #error "CAN_CLK_OUT pin defined but not the CAN_CLK_OUT_DIV" #endif /* driver interface functions */ static int _esp_can_init(candev_t *candev); static int _esp_can_send(candev_t *candev, const struct can_frame *frame); static void _esp_can_isr(candev_t *candev); static int _esp_can_set(candev_t *candev, canopt_t opt, void *value, size_t value_len); static int _esp_can_get(candev_t *candev, canopt_t opt, void *value, size_t max_len); static int _esp_can_abort(candev_t *candev, const struct can_frame *frame); static int _esp_can_set_filter(candev_t *candev, const struct can_filter *filter); static int _esp_can_remove_filter(candev_t *candev, const struct can_filter *filter); /* internal function declarations, we don't need the device since we have only one */ static void _esp_can_set_bittiming(can_t *dev); static void _esp_can_start(can_t *dev); static void _esp_can_stop(can_t *dev); static void _esp_can_power_up(can_t *dev); static void _esp_can_power_down(can_t *dev); static int _esp_can_set_mode(can_t *dev, canopt_state_t state); static void _esp_can_init_pins(void); static void _esp_can_deinit_pins(void); static void _esp_can_intr_handler(void *arg); /** ESP32 CAN low level device driver data */ static const candev_driver_t _esp_can_driver = { .send = _esp_can_send, .init = _esp_can_init, .isr = _esp_can_isr, .get = _esp_can_get, .set = _esp_can_set, .abort = _esp_can_abort, .set_filter = _esp_can_set_filter, .remove_filter = _esp_can_remove_filter, }; /** hardware dependent constants used for bit timing calculations */ static const struct can_bittiming_const bittiming_const = { .tseg1_min = 1, .tseg1_max = 16, .tseg2_min = 1, .tseg2_max = 8, .sjw_max = 4, .brp_min = 2, .brp_max = 128, .brp_inc = 2, }; static void _esp_can_isr(candev_t *candev) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p\n", __func__, candev); assert(dev); assert(dev->candev.event_callback); if (dev->events & ESP_CAN_EVENT_BUS_OFF) { dev->events &= ~ESP_CAN_EVENT_BUS_OFF; dev->candev.event_callback(&dev->candev, CANDEV_EVENT_BUS_OFF, NULL); } if (dev->events & ESP_CAN_EVENT_ERROR_PASSIVE) { dev->events &= ~ESP_CAN_EVENT_ERROR_PASSIVE; dev->candev.event_callback(&dev->candev, CANDEV_EVENT_ERROR_PASSIVE, NULL); } if (dev->events & ESP_CAN_EVENT_ERROR_WARNING) { dev->events &= ~ESP_CAN_EVENT_ERROR_WARNING; dev->candev.event_callback(&dev->candev, CANDEV_EVENT_ERROR_WARNING, NULL); } if (dev->events & ESP_CAN_EVENT_TX_ERROR) { /* a pending TX confirmation has also to be deleted on TX bus error */ dev->events &= ~ESP_CAN_EVENT_TX_ERROR; dev->events &= ~ESP_CAN_EVENT_TX_CONFIRMATION; if (dev->tx_frame) { /* handle the event only if there is still a frame in TX buffer */ dev->candev.event_callback(&dev->candev, CANDEV_EVENT_TX_ERROR, dev->tx_frame); dev->tx_frame = NULL; } } if (dev->events & ESP_CAN_EVENT_TX_CONFIRMATION) { dev->events &= ~ESP_CAN_EVENT_TX_CONFIRMATION; if (dev->tx_frame) { /* handle the event only if there is still a frame in TX buffer */ dev->candev.event_callback(&dev->candev, CANDEV_EVENT_TX_CONFIRMATION, dev->tx_frame); dev->tx_frame = NULL; } } if (dev->events & ESP_CAN_EVENT_RX_ERROR) { dev->events &= ~ESP_CAN_EVENT_RX_ERROR; dev->candev.event_callback(&dev->candev, CANDEV_EVENT_RX_ERROR, NULL); } if (dev->events & ESP_CAN_EVENT_RX_INDICATION) { dev->events &= ~ESP_CAN_EVENT_RX_INDICATION; while (dev->rx_frames_num) { dev->candev.event_callback(&dev->candev, CANDEV_EVENT_RX_INDICATION, &dev->rx_frames[dev->rx_frames_rptr]); dev->rx_frames_num--; dev->rx_frames_rptr++; dev->rx_frames_rptr &= ESP_CAN_MAX_RX_FRAMES-1; } } } twai_hal_context_t hw; static int _esp_can_init(candev_t *candev) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p\n", __func__, candev); assert(dev); /* power up and configure the CAN controller and initialize the pins */ _esp_can_power_up(dev); /* start the CAN controller in configured operation mode */ _esp_can_start(dev); return 0; } static int _esp_can_send(candev_t *candev, const struct can_frame *frame) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p frame=%p\n", __func__, candev, frame); assert(dev); assert(frame); critical_enter(); /* check wthere the device is already transmitting a frame */ if (dev->tx_frame != NULL) { critical_exit(); return -EBUSY; } /* save reference to frame in transmission (marks transmitter as busy) */ dev->tx_frame = (struct can_frame*)frame; /* prepare the frame as expected by ESP32 */ twai_hal_frame_t esp_frame = { }; esp_frame.dlc = frame->can_dlc; esp_frame.rtr = (frame->can_id & CAN_RTR_FLAG); esp_frame.frame_format = (frame->can_id & CAN_EFF_FLAG); /* esp_frame is a union that provides two views on the same memory: one * tailored for efficient access and the other for readable code. Likely * due to cppcheck not finding all headers it wrongly assumes that values * are assigned but never read again (unreadVariable). But the union members * are read via the aliases to the same memory. */ if (esp_frame.frame_format) { uint32_t id = frame->can_id & CAN_EFF_MASK; /* cppcheck-suppress unreadVariable */ esp_frame.extended.id[0] = (id >> 21) & 0xff; /* cppcheck-suppress unreadVariable */ esp_frame.extended.id[1] = (id >> 13) & 0xff; /* cppcheck-suppress unreadVariable */ esp_frame.extended.id[2] = (id >> 5) & 0xff; /* cppcheck-suppress unreadVariable */ esp_frame.extended.id[3] = (id << 3) & 0xff; } else { uint32_t id = frame->can_id & CAN_SFF_MASK; /* cppcheck-suppress unreadVariable */ esp_frame.standard.id[0] = (id >> 3) & 0xff; /* cppcheck-suppress unreadVariable */ esp_frame.standard.id[1] = (id << 5) & 0xff; } /* copy data from can_frame to esp_frame */ memcpy(esp_frame.frame_format ? &esp_frame.extended.data : &esp_frame.standard.data, frame->data, ESP_CAN_MAX_DATA_LEN); /* set the single shot transmit command without self-receiption */ esp_frame.single_shot = 1; esp_frame.self_reception = 0; /* place the frame in TX buffer and trigger the command */ twai_hal_set_tx_buffer_and_transmit(&hw, &esp_frame); critical_exit(); return 0; } static int _esp_can_set(candev_t *candev, canopt_t opt, void *value, size_t value_len) { can_t *dev = container_of(candev, can_t, candev); assert(dev); assert(value); int res = 0; switch (opt) { case CANOPT_BITTIMING: DEBUG("%s CANOPT_BITTIMING\n", __func__); if (value_len < sizeof(struct can_bittiming)) { DEBUG("%s size error\n", __func__); return -EOVERFLOW; } dev->candev.bittiming = *((struct can_bittiming*)value); _esp_can_stop(dev); _esp_can_set_bittiming(dev); _esp_can_start(dev); res = sizeof(struct can_bittiming); break; case CANOPT_STATE: DEBUG("%s CANOPT_STATE %d\n", __func__, *((canopt_state_t *)value)); if (dev->powered_up) { _esp_can_stop(dev); } res = _esp_can_set_mode(dev, *((canopt_state_t *)value)); if (dev->powered_up) { _esp_can_start(dev); } if (res == 0) { res = sizeof(uint16_t); } break; case CANOPT_TEC: DEBUG("%s %s\n", __func__, "CANOPT_TEC"); if (value_len < sizeof(uint16_t)) { DEBUG("%s size error\n", __func__); return -EOVERFLOW; } _esp_can_stop(dev); twai_ll_set_tec(hw.dev, *((uint16_t*)value)); _esp_can_start(dev); res = sizeof(uint16_t); break; case CANOPT_REC: DEBUG("%s %s\n", __func__, "CANOPT_REC"); if (value_len < sizeof(uint16_t)) { DEBUG("%s size error\n", __func__); return -EOVERFLOW; } _esp_can_stop(dev); twai_ll_set_rec(hw.dev, *((uint16_t*)value)); _esp_can_start(dev); res = sizeof(uint16_t); break; default: DEBUG("%s not supported opt\n", __func__); res = ENOTSUP; } return res; } static int _esp_can_get(candev_t *candev, canopt_t opt, void *value, size_t max_len) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s\n", __func__); assert(dev); assert(value); int res = 0; switch (opt) { case CANOPT_BITTIMING: DEBUG("%s CANOPT_BITTIMING\n", __func__); if (max_len < sizeof(struct can_bittiming)) { res = -EOVERFLOW; break; } *((struct can_bittiming*)value) = dev->candev.bittiming; res = sizeof(struct can_bittiming); break; case CANOPT_BITTIMING_CONST: DEBUG("%s CANOPT_BITTIMING_CONST\n", __func__); if (max_len < sizeof(struct can_bittiming_const)) { res = -EOVERFLOW; break; } *((struct can_bittiming_const*)value) = bittiming_const; res = sizeof(struct can_bittiming_const); break; case CANOPT_CLOCK: DEBUG("%s CANOPT_CLOCK\n", __func__); if (max_len < sizeof(uint32_t)) { res = -EOVERFLOW; break; } *((uint32_t *)value) = APB_CLK_FREQ; res = sizeof(uint32_t); break; case CANOPT_TEC: DEBUG("%s %s\n", __func__, "CANOPT_TEC"); if (max_len < sizeof(uint16_t)) { res = EOVERFLOW; break; } *((uint16_t *)value) = twai_ll_get_tec(hw.dev); res = sizeof(uint16_t); break; case CANOPT_REC: DEBUG("%s %s\n", __func__, "CANOPT_REC"); if (max_len < sizeof(uint16_t)) { res = EOVERFLOW; break; } *((uint16_t *)value) = twai_ll_get_rec(hw.dev); res = sizeof(uint16_t); break; case CANOPT_RX_FILTERS: if (max_len % sizeof(struct can_filter) != 0) { res = -EOVERFLOW; break; } struct can_filter *list = value; unsigned filter_num_max = max_len / sizeof(struct can_filter); unsigned filter_num = 0; unsigned i; for (i = 0; i < ESP_CAN_MAX_RX_FILTERS && filter_num < filter_num_max; i++) { if (dev->rx_filters[i].can_id != 0) { list[i] = dev->rx_filters[i]; filter_num++; } } res = filter_num * sizeof(struct can_filter); break; default: DEBUG("%s not supported opt\n", __func__); res = -ENOTSUP; } return res; } static int _esp_can_abort(candev_t *candev, const struct can_frame *frame) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p frame=%p\n", __func__, candev, frame); assert(dev); assert(frame); /* abort transmission command */ twai_ll_set_cmd_abort_tx(hw.dev); /* mark the transmitter as free */ dev->tx_frame = NULL; return -ENOTSUP; } static int _esp_can_set_filter(candev_t *candev, const struct can_filter *filter) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p filter=%p\n", __func__, candev, filter); assert(dev); assert(filter); int i; /* first, check whether filter is already set */ for (i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) { if (dev->rx_filters[i].can_id == filter->can_id) { DEBUG("%s filter already set\n", __func__); return i; } } /* next, search for free filter entry */ for (i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) { if (dev->rx_filters[i].can_id == 0) { break; } } if (i == ESP_CAN_MAX_RX_FILTERS) { DEBUG("%s no more filters available\n", __func__); return -EOVERFLOW; } /* set the filter and return the filter index */ dev->rx_filters[i] = *filter; dev->rx_filter_num++; return i; } static int _esp_can_remove_filter(candev_t *candev, const struct can_filter *filter) { can_t *dev = container_of(candev, can_t, candev); DEBUG("%s candev=%p filter=%p\n", __func__, candev, filter); assert(dev); assert(filter); /* search for the filter */ for (unsigned i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) { if (dev->rx_filters[i].can_id == filter->can_id) { /* mark the filter entry as not in use */ dev->rx_filters[i].can_id = 0; dev->rx_filter_num--; return 0; } } DEBUG("%s error filter not found\n", __func__); return -EOVERFLOW; } /** * Internal functions. */ static void _esp_can_start(can_t *dev) { DEBUG("%s dev=%p\n", __func__, dev); assert(dev); /* start the CAN controller in configured mode */ switch (dev->state) { case CANOPT_STATE_LISTEN_ONLY: twai_hal_start(&hw, TWAI_MODE_LISTEN_ONLY); break; case CANOPT_STATE_SLEEP: /* sleep mode is not supported, the normal mode is used instead */ case CANOPT_STATE_ON: twai_hal_start(&hw, TWAI_MODE_NORMAL); break; default: break; } } static void _esp_can_stop(can_t *dev) { DEBUG("%s dev=%p\n", __func__, dev); assert(dev); /* stop the CAN controller by entering the reset mode */ twai_hal_stop(&hw); } static void _esp_can_power_up(can_t *dev) { /** * Function esp_can_power_up * - powers up the CAN controller, * - initializes the HAL context, * - sets the timing and the acceptance filters according to configuration * - resets the error counters and sets the warning limit * * The CAN controller must be started in configured mode explicitly * afterwards using function _esp_can_start(). */ DEBUG("%s dev=%p\n", __func__, dev); assert(dev); /* just return when already powered up */ if (dev->powered_up) { return; } critical_enter(); /* power up the peripheral */ periph_module_reset(PERIPH_TWAI_MODULE); periph_module_enable(PERIPH_TWAI_MODULE); /* initialize the HAL context, on return the CAN controller is in listen * only mode but not yet started, the error counters are reset and * pending interrupts cleared */ if (!twai_hal_init(&hw)) { assert(false); } /* set bittiming from parameters as given in device data */ _esp_can_set_bittiming(dev); /* set warning limit */ twai_ll_set_err_warn_lim(hw.dev, ESP_CAN_ERROR_WARNING_LIMIT); /* route CAN interrupt source to CPU interrupt and enable it */ intr_matrix_set(PRO_CPU_NUM, ETS_TWAI_INTR_SOURCE, CPU_INUM_CAN); intr_cntrl_ll_set_int_handler(CPU_INUM_CAN, _esp_can_intr_handler, (void*)(uintptr_t)dev); intr_cntrl_ll_enable_interrupts(BIT(CPU_INUM_CAN)); /* initialize used GPIOs */ _esp_can_init_pins(); dev->powered_up = true; critical_exit(); } static void _esp_can_power_down(can_t *dev) { DEBUG("%s dev=%p\n", __func__, dev); assert(dev); /* just return when already powered down */ if (!dev->powered_up) { return; } /* deinitialize used GPIOs */ _esp_can_deinit_pins(); /* stop the CAN controller and deinitialize the HAL context */ twai_hal_stop(&hw); twai_hal_deinit(&hw); /* power down the CAN controller */ periph_module_disable(PERIPH_TWAI_MODULE); dev->powered_up = false; } static void _esp_can_init_pins(void) { DEBUG("%s\n", __func__); const can_conf_t *cfg = &candev_conf[0]; /* Init TX pin */ gpio_init(cfg->tx_pin, GPIO_OUT); esp_rom_gpio_connect_out_signal(cfg->tx_pin, TWAI_TX_IDX, false, false); esp_rom_gpio_pad_select_gpio(cfg->tx_pin); gpio_set_pin_usage(cfg->tx_pin, _CAN); /* Init RX pin */ gpio_init(cfg->rx_pin, GPIO_IN); esp_rom_gpio_connect_in_signal(cfg->rx_pin, TWAI_RX_IDX, false); esp_rom_gpio_pad_select_gpio(cfg->rx_pin); gpio_set_pin_usage(cfg->rx_pin, _CAN); #ifdef CAN_CLK_OUT /* Init CLK_OUT pin (optional) if defined */ gpio_init(cfg->clk_out_pin, GPIO_OD); esp_rom_gpio_connect_out_signal(cfg->clk_out_pin, TWAI_CLKOUT_IDX, false, false); esp_rom_gpio_pad_select_gpio(cfg->clk_out_pin); gpio_set_pin_usage(cfg->clk_out_pin, _CAN); #endif #ifdef CAN_BUS_ON_OFF /* Init BUS_ON_OFF pin pin (optional) if defined */ gpio_init(cfg->bus_on_of_pin, GPIO_OD); esp_rom_gpio_connect_out_signal(cfg->bus_on_of_pin, TWAI_BUS_OFF_ON_IDX, false, false); esp_rom_gpio_pad_select_gpio(cfg->bus_on_of_pin); gpio_set_pin_usage(cfg->bus_on_of_pin, _CAN); #endif } static void _esp_can_deinit_pins(void) { const can_conf_t *cfg = &candev_conf[0]; /* Reset TX pin */ gpio_set_pin_usage(cfg->tx_pin, _GPIO); gpio_init(cfg->tx_pin, GPIO_IN_PU); /* Reset RX pin */ gpio_set_pin_usage(cfg->rx_pin, _GPIO); gpio_init(cfg->rx_pin, GPIO_IN_PU); #ifdef CAN_CLK_OUT /* Reset CLK_OUT pin (optional) if defined */ gpio_set_pin_usage(cfg->clk_out_pin, _GPIO); gpio_init(cfg->clk_out_pin, GPIO_IN); #endif #ifdef CAN_BUS_ON_OFF /* Reset BUS_ON_OFF pin pin (optional) if defined */ gpio_set_pin_usage(cfg->bus_on_of_pin, _GPIO); gpio_init(cfg->bus_on_of_pin, GPIO_IN_PD); #endif } static int _esp_can_set_mode(can_t *dev, canopt_state_t state) { DEBUG("%s dev=%p state=%d\n", __func__, dev, state); assert(dev); critical_enter(); /* set the new mode */ dev->state = state; switch (state) { case CANOPT_STATE_OFF: /* stop and power down the CAN controller */ _esp_can_power_down(dev); break; case CANOPT_STATE_SLEEP: /* sleep mode is not supported, so CAN can't be powered down */ case CANOPT_STATE_LISTEN_ONLY: case CANOPT_STATE_ON: /* power up and (re)configure the CAN controller if necessary */ _esp_can_power_up(dev); /* restart the CAN controller in new mode */ _esp_can_stop(dev); _esp_can_start(dev); break; default: LOG_TAG_ERROR ("esp_can", "state value %d not supported\n", state); break; } critical_exit(); return 0; } static void IRAM_ATTR _esp_can_intr_handler(void *arg) { can_t* dev = (can_t *)(uintptr_t)arg; assert(arg); critical_enter(); uint32_t events = twai_hal_get_events(&hw); DEBUG("%s events=%08"PRIx32"\n", __func__, events); /* Arbitration Lost Interrupt */ if (events & TWAI_HAL_EVENT_ARB_LOST) { DEBUG("%s arbitration lost interrupt\n", __func__); /* can only happen during transmission, handle it as error in single shot transmission */ dev->events |= ESP_CAN_EVENT_TX_ERROR; } /* BUS_OFF state condition */ if (events & TWAI_HAL_EVENT_BUS_OFF) { DEBUG("%s bus-off state interrupt\n", __func__); /* save the event */ dev->events |= ESP_CAN_EVENT_BUS_OFF; } /* ERROR_WARNING state condition, RX/TX error counter are > 96 */ if (events & TWAI_HAL_EVENT_ABOVE_EWL) { DEBUG("%s error warning interrupt\n", __func__); /* save the event */ dev->events |= ESP_CAN_EVENT_ERROR_WARNING; } /* enter to / return from ERROR_PASSIVE state */ if (events & TWAI_HAL_EVENT_ERROR_PASSIVE) { DEBUG("%s error passive interrupt %"PRIu32" %"PRIu32"\n", __func__, twai_ll_get_tec(hw.dev), twai_ll_get_rec(hw.dev)); /* save the event */ dev->events |= ESP_CAN_EVENT_ERROR_PASSIVE; } /* * Bus Error Interrupt (bit, stuff, crc, form, ack), details are captured * in ECC register (see SJA1000 Data sheet, Table 20 and 21) */ if (events & TWAI_HAL_EVENT_BUS_ERR) { DEBUG("%s bus error interrupt\n", __func__); /* save the event */ dev->events |= ESP_CAN_EVENT_TX_ERROR; } /* TX buffer becomes free */ if (events & TWAI_HAL_EVENT_TX_BUFF_FREE) { DEBUG("%s transmit interrupt\n", __func__); /* save the event */ dev->events |= ESP_CAN_EVENT_TX_CONFIRMATION; } /* RX buffer has one or more frames */ if (events & TWAI_HAL_EVENT_RX_BUFF_FRAME) { /* get the number of messages in receive buffer */ uint32_t msg_cnt = twai_hal_get_rx_msg_count(&hw); DEBUG("%s receive interrupt, msg_cnt=%"PRIu32"\n", __func__, msg_cnt); for (unsigned i = 0; i < msg_cnt; i++) { twai_hal_frame_t esp_frame; if (twai_hal_read_rx_buffer_and_clear(&hw, &esp_frame) && (dev->rx_frames_num < ESP_CAN_MAX_RX_FRAMES)) { /* prepare the CAN frame from ESP32 CAN frame */ struct can_frame frame = {}; if (esp_frame.frame_format) { frame.can_id = esp_frame.extended.id[0]; frame.can_id = (frame.can_id << 8) | esp_frame.extended.id[1]; frame.can_id = (frame.can_id << 8) | esp_frame.extended.id[2]; frame.can_id = (frame.can_id << 5) | (esp_frame.extended.id[3] >> 3); memcpy(frame.data, &esp_frame.extended.data, CAN_MAX_DLEN); } else { frame.can_id = esp_frame.standard.id[0]; frame.can_id = (frame.can_id << 3) | (esp_frame.standard.id[1] >> 5); memcpy(frame.data, &esp_frame.standard.data, CAN_MAX_DLEN); } frame.can_id |= esp_frame.rtr ? CAN_RTR_FLAG : 0; frame.can_id |= esp_frame.frame_format ? CAN_EFF_FLAG : 0; frame.can_dlc = esp_frame.dlc; /* apply acceptance filters only if they are set */ unsigned f_id = 0; if (dev->rx_filter_num) { for (f_id = 0; f_id < ESP_CAN_MAX_RX_FILTERS; f_id++) { /* compared masked can_id with each filter */ struct can_filter* f = &dev->rx_filters[f_id]; if ((f->can_mask & f->can_id) == (f->can_mask & frame.can_id)) { /* break the loop on first match */ break; } } } /* * put the frame in the RX ring buffer if there are no * acceptance filters (f_id == 0) or one filter matched * (f_id < ESP_CAN_MAX_RX_FILTERS), otherwise drop it. */ if (f_id < ESP_CAN_MAX_RX_FILTERS) { dev->rx_frames[dev->rx_frames_wptr] = frame; dev->rx_frames_num++; dev->rx_frames_wptr++; dev->rx_frames_wptr &= ESP_CAN_MAX_RX_FRAMES-1; /* at least one RX frame has been saved */ dev->events |= ESP_CAN_EVENT_RX_INDICATION; } } else { DEBUG("%s receive buffer overrun\n", __func__); /* we use rx error since there is no separate overrun error */ dev->events |= ESP_CAN_EVENT_RX_ERROR; } } } DEBUG("%s events=%08"PRIx32"\n", __func__, dev->events); /* inform the upper layer that there are events to be handled */ if (dev->events && dev->candev.event_callback) { dev->candev.event_callback(&dev->candev, CANDEV_EVENT_ISR, NULL); } critical_exit(); } /* accept all CAN messages by default, filtering is done by software */ static const twai_filter_config_t twai_filter = { .single_filter = false, /* single filter */ .acceptance_mask = UINT32_MAX, /* all bits masked */ }; static void _esp_can_set_bittiming(can_t *dev) { /* sets the bus timing, the CAN controller has to stopped before using * function _esp_can_stop(dev) and has to be restartet using * function _esp_can_start() afterwards */ assert(dev); struct can_bittiming* timing = &dev->candev.bittiming; DEBUG("%s %p bitrate=%"PRIu32", brp=%"PRIu32", sample_point=%"PRIu32", " "tq=%"PRIu32", prop_seg=%"PRIu32" phase_seg1=%"PRIu32", " "phase_seg2=%"PRIu32", sjw =%"PRIu32"\n", __func__, dev, timing->bitrate, timing->brp, timing->sample_point, timing->tq, timing->prop_seg, timing->phase_seg1, timing->phase_seg2, timing->sjw); twai_timing_config_t twai_timing = { .brp = timing->brp, .sjw = timing->sjw, .tseg_1 = timing->prop_seg + timing->phase_seg1, .tseg_2 = timing->phase_seg2, }; twai_hal_configure(&hw, &twai_timing, &twai_filter, ESP_CAN_INTR_MASK, CAN_CLK_OUT_DIV); } void can_init(can_t *dev, const can_conf_t *conf) { DEBUG("%s dev=%p conf=%p\n", __func__, dev, conf); assert(dev); assert(conf); dev->candev.driver = &_esp_can_driver; dev->candev.bittiming.bitrate = conf->bitrate; /* determine the hardware bittiming constants */ struct can_bittiming_const timing_const = bittiming_const; /* calculate the initial bittimings from the bittiming constants */ can_device_calc_bittiming(ESP_CAN_CLOCK, &timing_const, &dev->candev.bittiming); /* initialize other members */ dev->state = CANOPT_STATE_SLEEP; dev->tx_frame = NULL; dev->rx_frames_wptr = 0; dev->rx_frames_rptr = 0; dev->rx_frames_num = 0; dev->rx_filter_num = 0; dev->powered_up = false; } void can_print_config(void) { printf("\tCAN_DEV(0)\ttxd=%d rxd=%d\n", CAN_TX, CAN_RX); } /**@}*/