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RIOT/sys/include/bhp/msg.h
2022-08-19 12:01:30 +02:00

107 lines
3.1 KiB
C

/*
* Copyright (C) 2022 HAW Hamburg
*
* 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 sys_bhp_msg Message based implementation of Bottom Half Processor
* @ingroup sys_bhp
*
* @note Offloading ISRs with messages is in general a terrible idea,
* because messages can be lost. Use it with care or prefer
* alternatives such as @ref sys_bhp_event.
*
* @brief Bottom Half Processor module for generic IRQ offloading using
* messages.
* @{
*
* @author José I. Alamos <jose.alamos@haw-hamburg.de>
*/
#ifndef BHP_MSG_H
#define BHP_MSG_H
#include "msg.h"
#include "thread.h"
#include "bhp.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief The message type to trigger Bottom Half Processing
*/
#define BHP_MSG_BH_REQUEST 0x1539
/**
* @brief Message based Bottom Half Processor descriptor
*/
typedef struct {
bhp_t bhp; /**< Bottom Half Processor descriptor */
kernel_pid_t pid; /**< PID of the thread that process the Bottom Half Processor */
msg_t msg; /**< Message containing the Bottom Half Processing request */
} bhp_msg_t;
/**
* @brief Init a Bottom Half Processor to be used with messages
* @post the target PID is set to @ref KERNEL_PID_UNDEF
*
* @param[in] bhp_msg The message based Bottom Half Processor descriptor
* @param[in] cb Bottom Half Processor callback
* @param[in] ctx Context of @p cb
*/
void bhp_msg_init(bhp_msg_t *bhp_msg, bhp_cb_t cb, void *ctx);
/**
* @brief Message based Bottom Half Processor ISR callback
* To be called from ISR in order to trigger the Bottom Half Processor.
* This sends a message with type @ref BHP_MSG_BH_REQUEST to the
* target thread, which should process the event accordingly by calling
* @ref bhp_msg_handler.
*
* @note This function asserts that the target PID is valid. Therefore, make sure
* to call @ref bhp_msg_claim_thread beforehand.
*
* @param[in] bhp_msg_ctx Pointer to the message based Bottom Half Processor
* (@ref bhp_msg_t)
* Bottom Half Processor.
*/
void bhp_msg_isr_cb(void *bhp_msg_ctx);
/**
* @brief Claim a thread with a message queue to be used as Bottom Half Processor.
*
* @param[in] bhp_msg The message based Bottom Half Processor descriptor
* @param[in] pid PID of the target thread
*/
static inline void bhp_msg_claim_thread(bhp_msg_t *bhp_msg, kernel_pid_t pid)
{
bhp_msg->pid = pid;
}
/**
* @brief Handle a Bottom Half Processor message with type @ref
* BHP_MSG_BH_REQUEST.
* This function will call @ref bhp_irq_handler internally.
*
* @note This function asserts that the message type is @ref BHP_MSG_BH_REQUEST.
*
* @param[in] msg Pointer to the Bottom Half Processor message.
*/
static inline void bhp_msg_handler(msg_t *msg)
{
assert(msg->type == BHP_MSG_BH_REQUEST);
bhp_irq_handler(msg->content.ptr);
}
#ifdef __cplusplus
}
#endif
#endif /* BHP_MSG_H */
/** @} */