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RIOT/cpu/esp32/include/can_esp.h
2022-07-14 15:51:47 +02:00

109 lines
3.5 KiB
C

/*
* 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.
*/
/**
* @defgroup cpu_esp32_esp_can ESP32 CAN controller
* @ingroup cpu_esp32
* @ingroup drivers_can
* @brief CAN controller driver for ESP32 (esp_can)
*
* The ESP32 intregates a CAN controller which is compatible with the
* NXP SJA1000 CAN controller. Thus, it is CAN 2.0B specification compliant
* and supports two message formats:
*
* - Base frame format (11-bit ID)
* - Extended frame format (29-bit ID)
*
* @note
* - ESP32 CAN does not support CAN-FD and is not CAN-FD tolerant.
* - ESP32 CAN does not support SJA1000's sleep mode and wake-up functionality.
*
* As with the SJA1000, the ESP32 CAN controller provides only the data link
* layer and the physical layer signaling sublayer. Therefore, depending on
* the physical layer requirements, an external transceiver module is required
* which converts the `CAN-RX` and `CAN-TX` signals of the ESP32 into `CAN_H`
* and `CAN_L` bus signals, e.g., the MCP2551 or SN65HVD23X transceiver for
* compatibility with ISO 11898-2.
*
* The driver realizes a low-level CAN driver interface for the ESP32 CAN
* controller and provides a CAN DLL device that can be used in RIOT's CAN
* protocol stack.
* It uses the ESP32 CAN controller in SJA1000 PeliCAN mode. Please refer the
* [SJA1000 Datasheet](https://www.nxp.com/documents/data_sheet/SJA1000.pdf)
* for detailed information about the CAN controller and its programming.
*
* @author Gunar Schorcht <gunar@schorcht.net>
* @{
* @file
*/
#ifndef CAN_ESP_H
#define CAN_ESP_H
#ifdef __cplusplus
extern "C" {
#endif
#include "can/candev.h"
#include "periph/gpio.h"
/** Number of receiver acceptance filters */
#define ESP_CAN_MAX_RX_FILTERS (16)
/** Number of frames in receiver buffer, must be a power of two */
#define ESP_CAN_MAX_RX_FRAMES (8)
/**
* Low level device structure for ESP32 CAN (extension of candev_t)
*/
typedef struct can {
candev_t candev; /**< candev base structure */
canopt_state_t state; /**< current state of device */
struct can_frame *tx_frame; /**< frame in transmission */
struct can_frame rx_frames[ESP_CAN_MAX_RX_FRAMES]; /**< frames received */
struct can_filter rx_filters[ESP_CAN_MAX_RX_FILTERS]; /**< acceptance filter list */
uint32_t rx_frames_wptr; /**< pointer to ring buffer for write */
uint32_t rx_frames_rptr; /**< pointer to ring buffer for read */
uint32_t rx_frames_num; /**< number of frames in ring buffer */
uint32_t rx_filter_num; /**< number of acceptance filters */
bool powered_up; /**< device is powered up */
uint32_t events; /**< events triggered by the last interrupt */
} can_t;
/** CAN device type can_t is redefined by ESP CAN */
#define HAVE_CAN_T
/**
* ESP CAN device configuration
*/
typedef struct {
uint32_t bitrate; /**< Bitrate */
gpio_t tx_pin; /**< CAN transceiver TX pin */
gpio_t rx_pin; /**< CAN transceiver RX pin */
#ifdef CAN_CLK_OUT
gpio_t clk_out_pin; /**< optional CLK_OUT pin */
#endif
#ifdef CAN_BUS_ON_OFF
gpio_t bus_on_off_pin; /**< optional BUS_ON_OFF pin */
#endif
} can_conf_t;
/** CAN device configuration type can_conf_t is redefined by ESP CAN */
#define HAVE_CAN_CONF_T
#ifdef __cplusplus
}
#endif
#endif /* CAN_ESP_H */
/** @} */