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zephyr/include/drivers/can.h

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/**
* @file
*
* @brief Public APIs for the CAN drivers.
*/
/*
* Copyright (c) 2018 Alexander Wachter
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_CAN_H_
#define ZEPHYR_INCLUDE_DRIVERS_CAN_H_
/**
* @brief CAN Interface
* @defgroup can_interface CAN Interface
* @ingroup io_interfaces
* @{
*/
#include <zephyr/types.h>
#include <device.h>
#include <string.h>
#ifdef __cplusplus
extern "C" {
#endif
#define CAN_EX_ID (1 << 31)
#define CAN_MAX_STD_ID (0x7FF)
#define CAN_STD_ID_MASK CAN_MAX_STD_ID
#define CAN_EXT_ID_MASK (0x1FFFFFFF)
#define CAN_MAX_DLC (8)
#define CAN_MAX_DLEN 8
/* CAN_TX_* are the error flags from tx_callback and send.*/
/** send successfully */
#define CAN_TX_OK (0)
/** general send error */
#define CAN_TX_ERR (-2)
/** bus arbitration lost during sending */
#define CAN_TX_ARB_LOST (-3)
/** controller is in bus off state */
#define CAN_TX_BUS_OFF (-4)
/** unexpected error */
#define CAN_TX_UNKNOWN (-5)
/** invalid parameter */
#define CAN_TX_EINVAL (-22)
/** attach_* failed because there is no unused filter left*/
#define CAN_NO_FREE_FILTER (-1)
/** operation timed out*/
#define CAN_TIMEOUT (-1)
/**
* @brief Statically define and initialize a can message queue.
*
* The message queue's ring buffer contains space for @a size messages.
*
* @param name Name of the message queue.
* @param size Number of can messages.
*/
#define CAN_DEFINE_MSGQ(name, size) \
K_MSGQ_DEFINE(name, sizeof(struct zcan_frame), size, 4)
/**
* @brief can_ide enum
* Define if the message has a standard (11bit) or extended (29bit)
* identifier
*/
enum can_ide {
CAN_STANDARD_IDENTIFIER,
CAN_EXTENDED_IDENTIFIER
};
/**
* @brief can_rtr enum
* Define if the message is a data or remote frame
*/
enum can_rtr {
CAN_DATAFRAME,
CAN_REMOTEREQUEST
};
/**
* @brief can_mode enum
* Defines the mode of the can controller
*/
enum can_mode {
/*Normal mode*/
CAN_NORMAL_MODE,
/*Controller is not allowed to send dominant bits*/
CAN_SILENT_MODE,
/*Controller is in loopback mode (receive own messages)*/
CAN_LOOPBACK_MODE,
/*Combination of loopback and silent*/
CAN_SILENT_LOOPBACK_MODE
};
/**
* @brief can_state enum
* Defines the possible states of the CAN bus
*/
enum can_state {
CAN_ERROR_ACTIVE,
CAN_ERROR_PASSIVE,
CAN_BUS_OFF,
CAN_BUS_UNKNOWN
};
/*
* Controller Area Network Identifier structure for Linux compatibility.
*
* The fields in this type are:
*
* bit 0-28 : CAN identifier (11/29 bit)
* bit 29 : error message frame flag (0 = data frame, 1 = error message)
* bit 30 : remote transmission request flag (1 = rtr frame)
* bit 31 : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
*/
typedef uint32_t canid_t;
/**
* @brief CAN frame structure that is compatible with Linux. This is mainly
* used by Socket CAN code.
*
* @details Used to pass CAN messages from userspace to the socket CAN and vice
* versa.
*/
struct can_frame {
/** 32 bit CAN_ID + EFF/RTR/ERR flags */
canid_t can_id;
/** The length of the message */
uint8_t can_dlc;
/** @cond INTERNAL_HIDDEN */
uint8_t pad; /* padding */
uint8_t res0; /* reserved / padding */
uint8_t res1; /* reserved / padding */
/** @endcond */
/** The message data */
uint8_t data[CAN_MAX_DLEN];
};
/**
* @brief CAN filter that is compatible with Linux. This is mainly used by
* Socket CAN code.
*
* @details A filter matches, when "received_can_id & mask == can_id & mask"
*/
struct can_filter {
canid_t can_id;
canid_t can_mask;
};
/**
* @brief CAN message structure
*
* Used to pass can messages from userspace to the driver and
* from driver to userspace
*
*/
struct zcan_frame {
/** Indicates the identifier type (standard or extended)
* use can_ide enum for assignment
*/
uint32_t id_type : 1;
/** Set the message to a transmission request instead of data frame
* use can_rtr enum for assignment
*/
uint32_t rtr : 1;
/** Message identifier*/
union {
uint32_t std_id : 11;
uint32_t ext_id : 29;
};
/** The length of the message (max. 8) in byte */
uint8_t dlc;
/** The message data*/
union {
uint8_t data[8];
uint32_t data_32[2];
};
#if defined(CONFIG_CAN_RX_TIMESTAMP)
/** Timer value of the CAN free running timer.
* The timer is incremented every bit time and captured at the start
* of frame bit (SOF).
*/
uint16_t timestamp;
#endif
} __packed;
/**
* @brief CAN filter structure
*
* Used to pass can identifier filter information to the driver.
* rtr_mask and *_id_mask are used to mask bits of the rtr and id fields.
* If the mask bit is 0, the value of the corresponding bit in the id or rtr
* field don't care for the filter matching.
*
*/
struct zcan_filter {
/** Indicates the identifier type (standard or extended)
* use can_ide enum for assignment
*/
uint32_t id_type : 1;
/** target state of the rtr bit */
uint32_t rtr : 1;
/** target state of the identifier */
union {
uint32_t std_id : 11;
uint32_t ext_id : 29;
};
/** rtr bit mask */
uint32_t rtr_mask : 1;
/** identifier mask*/
union {
uint32_t std_id_mask : 11;
uint32_t ext_id_mask : 29;
};
} __packed;
/**
* @brief can bus error count structure
*
* Used to pass the bus error counters to userspace
*/
struct can_bus_err_cnt {
uint8_t tx_err_cnt;
uint8_t rx_err_cnt;
};
/**
* @typedef can_tx_callback_t
* @brief Define the application callback handler function signature
*
* @param error_flags status of the performed send operation
* @param arg argument that was passed when the message was sent
*/
typedef void (*can_tx_callback_t)(uint32_t error_flags, void *arg);
/**
* @typedef can_rx_callback_t
* @brief Define the application callback handler function signature
* for receiving.
*
* @param msg received message
* @param arg argument that was passed when the filter was attached
*/
typedef void (*can_rx_callback_t)(struct zcan_frame *msg, void *arg);
/**
* @typedef can_state_change_isr_t
* @brief Defines the state change isr handler function signature
*
* @param state state of the node
* @param err_cnt struct with the error counter values
*/
typedef void(*can_state_change_isr_t)(enum can_state state,
struct can_bus_err_cnt err_cnt);
typedef int (*can_configure_t)(struct device *dev, enum can_mode mode,
uint32_t bitrate);
typedef int (*can_send_t)(struct device *dev, const struct zcan_frame *msg,
k_timeout_t timeout, can_tx_callback_t callback_isr,
void *callback_arg);
typedef int (*can_attach_msgq_t)(struct device *dev, struct k_msgq *msg_q,
const struct zcan_filter *filter);
typedef int (*can_attach_isr_t)(struct device *dev, can_rx_callback_t isr,
void *callback_arg,
const struct zcan_filter *filter);
typedef void (*can_detach_t)(struct device *dev, int filter_id);
typedef int (*can_recover_t)(struct device *dev, k_timeout_t timeout);
typedef enum can_state (*can_get_state_t)(struct device *dev,
struct can_bus_err_cnt *err_cnt);
typedef void(*can_register_state_change_isr_t)(struct device *dev,
can_state_change_isr_t isr);
#ifndef CONFIG_CAN_WORKQ_FRAMES_BUF_CNT
#define CONFIG_CAN_WORKQ_FRAMES_BUF_CNT 4
#endif
struct can_frame_buffer {
struct zcan_frame buf[CONFIG_CAN_WORKQ_FRAMES_BUF_CNT];
uint16_t head;
uint16_t tail;
};
/**
* @brief CAN work structure
*
* Used to attach a work queue to a filter.
*/
struct zcan_work {
struct k_work work_item;
struct k_work_q *work_queue;
struct can_frame_buffer buf;
can_rx_callback_t cb;
void *cb_arg;
};
__subsystem struct can_driver_api {
can_configure_t configure;
can_send_t send;
can_attach_isr_t attach_isr;
can_detach_t detach;
#ifndef CONFIG_CAN_AUTO_BUS_OFF_RECOVERY
can_recover_t recover;
#endif
can_get_state_t get_state;
can_register_state_change_isr_t register_state_change_isr;
};
/**
* @brief Perform data transfer to CAN bus.
*
* This routine provides a generic interface to perform data transfer
* to the can bus. Use can_write() for simple write.
* *
* @param dev Pointer to the device structure for the driver instance.
* @param msg Message to transfer.
* @param timeout Waiting for empty tx mailbox timeout or K_FOREVER.
* @param callback_isr Is called when message was sent or a transmission error
* occurred. If NULL, this function is blocking until
* message is sent. This must be NULL if called from user
* mode.
* @param callback_arg This will be passed whenever the isr is called.
*
* @retval 0 If successful.
* @retval CAN_TX_* on failure.
*/
__syscall int can_send(struct device *dev, const struct zcan_frame *msg,
k_timeout_t timeout, can_tx_callback_t callback_isr,
void *callback_arg);
static inline int z_impl_can_send(struct device *dev,
const struct zcan_frame *msg,
k_timeout_t timeout,
can_tx_callback_t callback_isr,
void *callback_arg)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->send(dev, msg, timeout, callback_isr, callback_arg);
}
/*
* Derived can APIs -- all implemented in terms of can_send()
*/
/**
* @brief Write a set amount of data to the can bus.
*
* This routine writes a set amount of data synchronously.
*
* @param dev Pointer to the device structure for the driver instance.
* @param data Data to send.
* @param length Number of bytes to write (max. 8).
* @param id Identifier of the can message.
* @param rtr Send remote transmission request or data frame
* @param timeout Waiting for empty tx mailbox timeout or K_FOREVER
*
* @retval 0 If successful.
* @retval -EIO General input / output error.
* @retval -EINVAL if length > 8.
*/
static inline int can_write(struct device *dev, const uint8_t *data, uint8_t length,
uint32_t id, enum can_rtr rtr, k_timeout_t timeout)
{
struct zcan_frame msg;
if (length > 8) {
return -EINVAL;
}
if (id > CAN_MAX_STD_ID) {
msg.id_type = CAN_EXTENDED_IDENTIFIER;
msg.ext_id = id & CAN_EXT_ID_MASK;
} else {
msg.id_type = CAN_STANDARD_IDENTIFIER;
msg.std_id = id;
}
msg.dlc = length;
msg.rtr = rtr;
memcpy(msg.data, data, length);
return can_send(dev, &msg, timeout, NULL, NULL);
}
/**
* @brief Attach a CAN work queue to a single or group of identifiers.
*
* This routine attaches a work queue to identifiers specified by a filter.
* Whenever the filter matches, the message is pushed to the buffer
* of the zcan_work structure and the work element is put to the workqueue.
* If a message passes more than one filter the priority of the match
* is hardware dependent.
* A CAN work queue can be attached to more than one filter.
* The work queue must be initialized before and the caller must have
* appropriate permissions on it.
*
* @param dev Pointer to the device structure for the driver instance.
* @param work_q Pointer to the already initialized work queue.
* @param work Pointer to a zcan_work. The work will be initialized.
* @param callback This function is called by workq whenever a message arrives.
* @param callback_arg Is passed to the callback when called.
* @param filter Pointer to a zcan_filter structure defining the id
* filtering.
*
* @retval filter_id on success.
* @retval CAN_NO_FREE_FILTER if there is no filter left.
*/
int can_attach_workq(struct device *dev, struct k_work_q *work_q,
struct zcan_work *work,
can_rx_callback_t callback, void *callback_arg,
const struct zcan_filter *filter);
/**
* @brief Attach a message queue to a single or group of identifiers.
*
* This routine attaches a message queue to identifiers specified by
* a filter. Whenever the filter matches, the message is pushed to the queue
* If a message passes more than one filter the priority of the match
* is hardware dependent.
* A message queue can be attached to more than one filter.
* The message queue must me initialized before, and the caller must have
* appropriate permissions on it.
*
* @param dev Pointer to the device structure for the driver instance.
* @param msg_q Pointer to the already initialized message queue.
* @param filter Pointer to a zcan_filter structure defining the id
* filtering.
*
* @retval filter_id on success.
* @retval CAN_NO_FREE_FILTER if there is no filter left.
*/
__syscall int can_attach_msgq(struct device *dev, struct k_msgq *msg_q,
const struct zcan_filter *filter);
/**
* @brief Attach an isr callback function to a single or group of identifiers.
*
* This routine attaches an isr callback to identifiers specified by
* a filter. Whenever the filter matches, the callback function is called
* with isr context.
* If a message passes more than one filter the priority of the match
* is hardware dependent.
* A callback function can be attached to more than one filter.
* *
* @param dev Pointer to the device structure for the driver instance.
* @param isr Callback function pointer.
* @param callback_arg This will be passed whenever the isr is called.
* @param filter Pointer to a zcan_filter structure defining the id
* filtering.
*
* @retval filter_id on success.
* @retval CAN_NO_FREE_FILTER if there is no filter left.
*/
static inline int can_attach_isr(struct device *dev,
can_rx_callback_t isr,
void *callback_arg,
const struct zcan_filter *filter)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->attach_isr(dev, isr, callback_arg, filter);
}
/**
* @brief Detach an isr or message queue from the identifier filtering.
*
* This routine detaches an isr callback or message queue from the identifier
* filtering.
* *
* @param dev Pointer to the device structure for the driver instance.
* @param filter_id filter id returned by can_attach_isr or can_attach_msgq.
*
* @retval none
*/
__syscall void can_detach(struct device *dev, int filter_id);
static inline void z_impl_can_detach(struct device *dev, int filter_id)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->detach(dev, filter_id);
}
/**
* @brief Configure operation of a host controller.
*
* @param dev Pointer to the device structure for the driver instance.
* @param mode Operation mode
* @param bitrate bus-speed in Baud/s
*
* @retval 0 If successful.
* @retval -EIO General input / output error, failed to configure device.
*/
__syscall int can_configure(struct device *dev, enum can_mode mode,
uint32_t bitrate);
static inline int z_impl_can_configure(struct device *dev, enum can_mode mode,
uint32_t bitrate)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->configure(dev, mode, bitrate);
}
/**
* @brief Get current state
*
* Returns the actual state of the CAN controller.
*
* @param dev Pointer to the device structure for the driver instance.
* @param err_cnt Pointer to the err_cnt destination structure or NULL.
*
* @retval state
*/
__syscall enum can_state can_get_state(struct device *dev,
struct can_bus_err_cnt *err_cnt);
static inline
enum can_state z_impl_can_get_state(struct device *dev,
struct can_bus_err_cnt *err_cnt)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->get_state(dev, err_cnt);
}
/**
* @brief Recover from bus-off state
*
* Recover the CAN controller from bus-off state to error-active state.
*
* @param dev Pointer to the device structure for the driver instance.
* @param timeout Timeout for waiting for the recovery or K_FOREVER.
*
* @retval 0 on success.
* @retval CAN_TIMEOUT on timeout.
*/
#ifndef CONFIG_CAN_AUTO_BUS_OFF_RECOVERY
__syscall int can_recover(struct device *dev, k_timeout_t timeout);
static inline int z_impl_can_recover(struct device *dev, k_timeout_t timeout)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->recover(dev, timeout);
}
#else
/* This implementation prevents inking errors for auto recovery */
static inline int z_impl_can_recover(struct device *dev, k_timeout_t timeout)
{
return 0;
}
#endif /* CONFIG_CAN_AUTO_BUS_OFF_RECOVERY */
/**
* @brief Register an ISR callback for state change interrupt
*
* Only one callback can be registered per controller.
* Calling this function again, overrides the previous call.
*
* @param dev Pointer to the device structure for the driver instance.
* @param isr Pointer to ISR
*/
static inline
void can_register_state_change_isr(struct device *dev,
can_state_change_isr_t isr)
{
const struct can_driver_api *api =
(const struct can_driver_api *)dev->driver_api;
return api->register_state_change_isr(dev, isr);
}
/**
* @brief Converter that translates between can_frame and zcan_frame structs.
*
* @param frame Pointer to can_frame struct.
* @param zframe Pointer to zcan_frame struct.
*/
static inline void can_copy_frame_to_zframe(const struct can_frame *frame,
struct zcan_frame *zframe)
{
zframe->id_type = (frame->can_id & BIT(31)) >> 31;
zframe->rtr = (frame->can_id & BIT(30)) >> 30;
zframe->ext_id = frame->can_id & BIT_MASK(29);
zframe->dlc = frame->can_dlc;
memcpy(zframe->data, frame->data, sizeof(zframe->data));
}
/**
* @brief Converter that translates between zcan_frame and can_frame structs.
*
* @param zframe Pointer to zcan_frame struct.
* @param frame Pointer to can_frame struct.
*/
static inline void can_copy_zframe_to_frame(const struct zcan_frame *zframe,
struct can_frame *frame)
{
frame->can_id = (zframe->id_type << 31) | (zframe->rtr << 30) |
(zframe->id_type == CAN_STANDARD_IDENTIFIER ? zframe->std_id :
zframe->ext_id);
frame->can_dlc = zframe->dlc;
memcpy(frame->data, zframe->data, sizeof(frame->data));
}
/**
* @brief Converter that translates between can_filter and zcan_frame_filter
* structs.
*
* @param filter Pointer to can_filter struct.
* @param zfilter Pointer to zcan_frame_filter struct.
*/
static inline
void can_copy_filter_to_zfilter(const struct can_filter *filter,
struct zcan_filter *zfilter)
{
zfilter->id_type = (filter->can_id & BIT(31)) >> 31;
zfilter->rtr = (filter->can_id & BIT(30)) >> 30;
zfilter->ext_id = filter->can_id & BIT_MASK(29);
zfilter->rtr_mask = (filter->can_mask & BIT(30)) >> 30;
zfilter->ext_id_mask = filter->can_mask & BIT_MASK(29);
}
/**
* @brief Converter that translates between zcan_filter and can_filter
* structs.
*
* @param zfilter Pointer to zcan_filter struct.
* @param filter Pointer to can_filter struct.
*/
static inline
void can_copy_zfilter_to_filter(const struct zcan_filter *zfilter,
struct can_filter *filter)
{
filter->can_id = (zfilter->id_type << 31) |
(zfilter->rtr << 30) | zfilter->ext_id;
filter->can_mask = (zfilter->rtr_mask << 30) |
(zfilter->id_type << 31) | zfilter->ext_id_mask;
}
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#include <syscalls/can.h>
#endif /* ZEPHYR_INCLUDE_DRIVERS_CAN_H_ */
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