// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD // // 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. #ifndef _DRIVER_CAN_H_ #define _DRIVER_CAN_H_ #ifdef __cplusplus extern "C" { #endif #include "freertos/FreeRTOS.h" #include "esp_types.h" #include "esp_intr.h" #include "esp_err.h" #include "gpio.h" /* -------------------- Default initializers and flags ---------------------- */ /** @cond */ //Doxy command to hide preprocessor definitions from docs /** * @brief Initializer macro for general configuration structure. * * This initializer macros allows the TX GPIO, RX GPIO, and operating mode to be * configured. The other members of the general configuration structure are * assigned default values. */ #define CAN_GENERAL_CONFIG_DEFAULT(tx_io_num, rx_io_num, op_mode) {.mode = op_mode, .tx_io = tx_io_num, .rx_io = rx_io_num, \ .clkout_io = CAN_IO_UNUSED, .bus_off_io = CAN_IO_UNUSED, \ .tx_queue_len = 5, .rx_queue_len = 5, \ .alerts_enabled = CAN_ALERT_NONE, .clkout_divider = 0, } /** * @brief Initializer macros for timing configuration structure * * The following initializer macros offer commonly found bit rates. * * @note These timing values are based on the assumption APB clock is at 80MHz */ #define CAN_TIMING_CONFIG_25KBITS() {.brp = 128, .tseg_1 = 16, .tseg_2 = 8, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_50KBITS() {.brp = 80, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_100KBITS() {.brp = 40, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_125KBITS() {.brp = 32, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_250KBITS() {.brp = 16, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_500KBITS() {.brp = 8, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_800KBITS() {.brp = 4, .tseg_1 = 16, .tseg_2 = 8, .sjw = 3, .triple_sampling = false} #define CAN_TIMING_CONFIG_1MBITS() {.brp = 4, .tseg_1 = 15, .tseg_2 = 4, .sjw = 3, .triple_sampling = false} /** * @brief Initializer macro for filter configuration to accept all IDs */ #define CAN_FILTER_CONFIG_ACCEPT_ALL() {.acceptance_code = 0, .acceptance_mask = 0xFFFFFFFF, .single_filter = true} /** * @brief Alert flags * * The following flags represents the various kind of alerts available in * the CAN driver. These flags can be used when configuring/reconfiguring * alerts, or when calling can_read_alerts(). * * @note The CAN_ALERT_AND_LOG flag is not an actual alert, but will configure * the CAN driver to log to UART when an enabled alert occurs. */ #define CAN_ALERT_TX_IDLE 0x0001 /**< Alert(1): No more messages to transmit */ #define CAN_ALERT_TX_SUCCESS 0x0002 /**< Alert(2): The previous transmission was successful */ #define CAN_ALERT_BELOW_ERR_WARN 0x0004 /**< Alert(4): Both error counters have dropped below error warning limit */ #define CAN_ALERT_ERR_ACTIVE 0x0008 /**< Alert(8): CAN controller has become error active */ #define CAN_ALERT_RECOVERY_IN_PROGRESS 0x0010 /**< Alert(16): CAN controller is undergoing bus recovery */ #define CAN_ALERT_BUS_RECOVERED 0x0020 /**< Alert(32): CAN controller has successfully completed bus recovery */ #define CAN_ALERT_ARB_LOST 0x0040 /**< Alert(64): The previous transmission lost arbitration */ #define CAN_ALERT_ABOVE_ERR_WARN 0x0080 /**< Alert(128): One of the error counters have exceeded the error warning limit */ #define CAN_ALERT_BUS_ERROR 0x0100 /**< Alert(256): A (Bit, Stuff, CRC, Form, ACK) error has occurred on the bus */ #define CAN_ALERT_TX_FAILED 0x0200 /**< Alert(512): The previous transmission has failed (for single shot transmission) */ #define CAN_ALERT_RX_QUEUE_FULL 0x0400 /**< Alert(1024): The RX queue is full causing a frame to be lost */ #define CAN_ALERT_ERR_PASS 0x0800 /**< Alert(2048): CAN controller has become error passive */ #define CAN_ALERT_BUS_OFF 0x1000 /**< Alert(4096): Bus-off condition occurred. CAN controller can no longer influence bus */ #define CAN_ALERT_ALL 0x1FFF /**< Bit mask to enable all alerts during configuration */ #define CAN_ALERT_NONE 0x0000 /**< Bit mask to disable all alerts during configuration */ #define CAN_ALERT_AND_LOG 0x2000 /**< Bit mask to enable alerts to also be logged when they occur */ /** * @brief Message flags * * The message flags are used to indicate the type of message transmitted/received. * Some flags also specify the type of transmission. */ #define CAN_MSG_FLAG_NONE 0x00 /**< No message flags (Standard Frame Format) */ #define CAN_MSG_FLAG_EXTD 0x01 /**< Extended Frame Format (29bit ID) */ #define CAN_MSG_FLAG_RTR 0x02 /**< Message is a Remote Transmit Request */ #define CAN_MSG_FLAG_SS 0x04 /**< Transmit as a Single Shot Transmission */ #define CAN_MSG_FLAG_SELF 0x08 /**< Transmit as a Self Reception Request */ #define CAN_MSG_FLAG_DLC_NON_COMP 0x10 /**< Message's Data length code is larger than 8. This will break compliance with CAN2.0B */ /** * @brief Miscellaneous macros */ #define CAN_EXTD_ID_MASK 0x1FFFFFFF /**< Bit mask for 29 bit Extended Frame Format ID */ #define CAN_STD_ID_MASK 0x7FF /**< Bit mask for 11 bit Standard Frame Format ID */ #define CAN_MAX_DATA_LEN 8 /**< Maximum number of data bytes in a CAN2.0B frame */ #define CAN_IO_UNUSED ((gpio_num_t) -1) /**< Marks GPIO as unused in CAN configuration */ /** @endcond */ /* ----------------------- Enum and Struct Definitions ---------------------- */ /** * @brief CAN driver operating modes */ typedef enum { CAN_MODE_NORMAL, /**< Normal operating mode where CAN controller can send/receive/acknowledge messages */ CAN_MODE_NO_ACK, /**< Transmission does not require acknowledgment. Use this mode for self testing */ CAN_MODE_LISTEN_ONLY, /**< The CAN controller will not influence the bus (No transmissions or acknowledgments) but can receive messages */ } can_mode_t; /** * @brief CAN driver states */ typedef enum { CAN_STATE_STOPPED, /**< Stopped state. The CAN controller will not participate in any CAN bus activities */ CAN_STATE_RUNNING, /**< Running state. The CAN controller can transmit and receive messages */ CAN_STATE_BUS_OFF, /**< Bus-off state. The CAN controller cannot participate in bus activities until it has recovered */ CAN_STATE_RECOVERING, /**< Recovering state. The CAN controller is undergoing bus recovery */ } can_state_t; /** * @brief Structure for general configuration of the CAN driver * * @note Macro initializers are available for this structure */ typedef struct { can_mode_t mode; /**< Mode of CAN controller */ gpio_num_t tx_io; /**< Transmit GPIO number */ gpio_num_t rx_io; /**< Receive GPIO number */ gpio_num_t clkout_io; /**< CLKOUT GPIO number (optional, set to -1 if unused) */ gpio_num_t bus_off_io; /**< Bus off indicator GPIO number (optional, set to -1 if unused) */ uint32_t tx_queue_len; /**< Number of messages TX queue can hold (set to 0 to disable TX Queue) */ uint32_t rx_queue_len; /**< Number of messages RX queue can hold */ uint32_t alerts_enabled; /**< Bit field of alerts to enable (see documentation) */ uint32_t clkout_divider; /**< CLKOUT divider. Can be 1 or any even number from 2 to 14 (optional, set to 0 if unused) */ } can_general_config_t; /** * @brief Structure for bit timing configuration of the CAN driver * * @note Macro initializers are available for this structure */ typedef struct { uint8_t brp; /**< Baudrate prescaler (APB clock divider, even number from 2 to 128) */ uint8_t tseg_1; /**< Timing segment 1 (Number of time quanta, between 1 to 16) */ uint8_t tseg_2; /**< Timing segment 2 (Number of time quanta, 1 to 8) */ uint8_t sjw; /**< Synchronization Jump Width (Max time quanta jump for synchronize from 1 to 4) */ bool triple_sampling; /**< Enables triple sampling when the CAN controller samples a bit */ } can_timing_config_t; /** * @brief Structure for acceptance filter configuration of the CAN driver (see documentation) * * @note Macro initializers are available for this structure */ typedef struct { uint32_t acceptance_code; /**< 32-bit acceptance code */ uint32_t acceptance_mask; /**< 32-bit acceptance mask */ bool single_filter; /**< Use Single Filter Mode (see documentation) */ } can_filter_config_t; /** * @brief Structure to store status information of CAN driver */ typedef struct { can_state_t state; /**< Current state of CAN controller (Stopped/Running/Bus-Off/Recovery) */ uint32_t msgs_to_tx; /**< Number of messages queued for transmission or awaiting transmission completion */ uint32_t msgs_to_rx; /**< Number of messages in RX queue waiting to be read */ uint32_t tx_error_counter; /**< Current value of Transmit Error Counter */ uint32_t rx_error_counter; /**< Current value of Receive Error Counter */ uint32_t tx_failed_count; /**< Number of messages that failed transmissions */ uint32_t rx_missed_count; /**< Number of messages that were lost due to a full RX queue */ uint32_t arb_lost_count; /**< Number of instances arbitration was lost */ uint32_t bus_error_count; /**< Number of instances a bus error has occurred */ } can_status_info_t; /** * @brief Structure to store a CAN message * * @note The flags member is used to control the message type, and transmission * type (see documentation for message flags) */ typedef struct { uint32_t flags; /**< Bit field of message flags indicates frame/transmission type (see documentation) */ uint32_t identifier; /**< 11 or 29 bit identifier */ uint8_t data_length_code; /**< Data length code */ uint8_t data[CAN_MAX_DATA_LEN]; /**< Data bytes (not relevant in RTR frame) */ } can_message_t; /* ----------------------------- Public API -------------------------------- */ /** * @brief Install CAN driver * * This function installs the CAN driver using three configuration structures. * The required memory is allocated and the CAN driver is placed in the stopped * state after running this function. * * @param[in] g_config General configuration structure * @param[in] t_config Timing configuration structure * @param[in] f_config Filter configuration structure * * @note Macro initializers are available for the configuration structures (see documentation) * * @note To reinstall the CAN driver, call can_driver_uninstall() first * * @return * - ESP_OK: Successfully installed CAN driver * - ESP_ERR_INVALID_ARG: Arguments are invalid * - ESP_ERR_NO_MEM: Insufficient memory * - ESP_ERR_INVALID_STATE: Driver is already installed */ esp_err_t can_driver_install(const can_general_config_t *g_config, const can_timing_config_t *t_config, const can_filter_config_t *f_config); /** * @brief Uninstall the CAN driver * * This function uninstalls the CAN driver, freeing the memory utilized by the * driver. This function can only be called when the driver is in the stopped * state or the bus-off state. * * @warning The application must ensure that no tasks are blocked on TX/RX * queues or alerts when this function is called. * * @return * - ESP_OK: Successfully uninstalled CAN driver * - ESP_ERR_INVALID_STATE: Driver is not in stopped/bus-off state, or is not installed */ esp_err_t can_driver_uninstall(); /** * @brief Start the CAN driver * * This function starts the CAN driver, putting the CAN driver into the running * state. This allows the CAN driver to participate in CAN bus activities such * as transmitting/receiving messages. The RX queue is reset in this function, * clearing any unread messages. This function can only be called when the CAN * driver is in the stopped state. * * @return * - ESP_OK: CAN driver is now running * - ESP_ERR_INVALID_STATE: Driver is not in stopped state, or is not installed */ esp_err_t can_start(); /** * @brief Stop the CAN driver * * This function stops the CAN driver, preventing any further message from being * transmitted or received until can_start() is called. Any messages in the TX * queue are cleared. Any messages in the RX queue should be read by the * application after this function is called. This function can only be called * when the CAN driver is in the running state. * * @warning A message currently being transmitted/received on the CAN bus will * be ceased immediately. This may lead to other CAN nodes interpreting * the unfinished message as an error. * * @return * - ESP_OK: CAN driver is now Stopped * - ESP_ERR_INVALID_STATE: Driver is not in running state, or is not installed */ esp_err_t can_stop(); /** * @brief Transmit a CAN message * * This function queues a CAN message for transmission. Transmission will start * immediately if no other messages are queued for transmission. If the TX queue * is full, this function will block until more space becomes available or until * it timesout. If the TX queue is disabled (TX queue length = 0 in configuration), * this function will return immediately if another message is undergoing * transmission. This function can only be called when the CAN driver is in the * running state and cannot be called under Listen Only Mode. * * @param[in] message Message to transmit * @param[in] ticks_to_wait Number of FreeRTOS ticks to block on the TX queue * * @note This function does not guarantee that the transmission is successful. * The TX_SUCCESS/TX_FAILED alert can be enabled to alert the application * upon the success/failure of a transmission. * * @note The TX_IDLE alert can be used to alert the application when no other * messages are awaiting transmission. * * @return * - ESP_OK: Transmission successfully queued/initiated * - ESP_ERR_INVALID_ARG: Arguments are invalid * - ESP_ERR_TIMEOUT: Timed out waiting for space on TX queue * - ESP_FAIL: TX queue is disabled and another message is currently transmitting * - ESP_ERR_INVALID_STATE: CAN driver is not in running state, or is not installed * - ESP_ERR_NOT_SUPPORTED: Listen Only Mode does not support transmissions */ esp_err_t can_transmit(const can_message_t *message, TickType_t ticks_to_wait); /** * @brief Receive a CAN message * * This function receives a message from the RX queue. The flags field of the * message structure will indicate the type of message received. This function * will block if there are no messages in the RX queue * * @param[out] message Received message * @param[in] ticks_to_wait Number of FreeRTOS ticks to block on RX queue * * @warning The flags field of the received message should be checked to determine * if the received message contains any data bytes. * * @return * - ESP_OK: Message successfully received from RX queue * - ESP_ERR_TIMEOUT: Timed out waiting for message * - ESP_ERR_INVALID_ARG: Arguments are invalid * - ESP_ERR_INVALID_STATE: CAN driver is not installed */ esp_err_t can_receive(can_message_t *message, TickType_t ticks_to_wait); /** * @brief Read CAN driver alerts * * This function will read the alerts raised by the CAN driver. If no alert has * been when this function is called, this function will block until an alert * occurs or until it timeouts. * * @param[out] alerts Bit field of raised alerts (see documentation for alert flags) * @param[in] ticks_to_wait Number of FreeRTOS ticks to block for alert * * @note Multiple alerts can be raised simultaneously. The application should * check for all alerts that have been enabled. * * @return * - ESP_OK: Alerts read * - ESP_ERR_TIMEOUT: Timed out waiting for alerts * - ESP_ERR_INVALID_ARG: Arguments are invalid * - ESP_ERR_INVALID_STATE: CAN driver is not installed */ esp_err_t can_read_alerts(uint32_t *alerts, TickType_t ticks_to_wait); /** * @brief Reconfigure which alerts are enabled * * This function reconfigures which alerts are enabled. If there are alerts * which have not been read whilst reconfiguring, this function can read those * alerts. * * @param[in] alerts_enabled Bit field of alerts to enable (see documentation for alert flags) * @param[out] current_alerts Bit field of currently raised alerts. Set to NULL if unused * * @return * - ESP_OK: Alerts reconfigured * - ESP_ERR_INVALID_STATE: CAN driver is not installed */ esp_err_t can_reconfigure_alerts(uint32_t alerts_enabled, uint32_t *current_alerts); /** * @brief Start the bus recovery process * * This function initiates the bus recovery process when the CAN driver is in * the bus-off state. Once initiated, the CAN driver will enter the recovering * state and wait for 128 occurrences of the bus-free signal on the CAN bus * before returning to the stopped state. This function will reset the TX queue, * clearing any messages pending transmission. * * @note The BUS_RECOVERED alert can be enabled to alert the application when * the bus recovery process completes. * * @return * - ESP_OK: Bus recovery started * - ESP_ERR_INVALID_STATE: CAN driver is not in the bus-off state, or is not installed */ esp_err_t can_initiate_recovery(); /** * @brief Get current status information of the CAN driver * * @param[out] status_info Status information * * @return * - ESP_OK: Status information retrieved * - ESP_ERR_INVALID_ARG: Arguments are invalid * - ESP_ERR_INVALID_STATE: CAN driver is not installed */ esp_err_t can_get_status_info(can_status_info_t *status_info); /** * @brief Clear the transmit queue * * This function will clear the transmit queue of all messages. * * @note The transmit queue is automatically cleared when can_stop() or * can_initiate_recovery() is called. * * @return * - ESP_OK: Transmit queue cleared * - ESP_ERR_INVALID_STATE: CAN driver is not installed or TX queue is disabled */ esp_err_t can_clear_transmit_queue(); /** * @brief Clear the receive queue * * This function will clear the receive queue of all messages. * * @note The receive queue is automatically cleared when can_start() is * called. * * @return * - ESP_OK: Transmit queue cleared * - ESP_ERR_INVALID_STATE: CAN driver is not installed */ esp_err_t can_clear_receive_queue(); #ifdef __cplusplus } #endif #endif /*_DRIVER_CAN_H_*/