Files
OpenCellular/include/task.h
Randall Spangler 1ce694189a Add IRQ constants, and task functions to enable/disable/trigger IRQs.
The constants don't work with the DECLARE_IRQ() macro yet, because it
relies on stringizing the IRQ number.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=none
TEST=none

Change-Id: Ie6ddecd79e28c319b095089131579ba994a17da3
(cherry picked from commit e24904644a977f2618f51629cc066b93a3d53595)
2011-12-12 14:23:04 -08:00

110 lines
3.1 KiB
C

/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Task scheduling / events module for Chrome EC operating system */
#ifndef __EC_TASK_H
#define __EC_TASK_H
#include "common.h"
#include "task_id.h"
/**
* Return true if we are in interrupt context
*/
inline int in_interrupt_context(void);
/**
* Send a message to a task and wake it up if it is higher priority than us
*
* tskid : identifier of the receiver task
* from : identifier of the sender of the message
* wait : after sending, de-schedule the calling task to wait for the answer
*
* returns the bitmap of events which have occured.
*
* Can be called both in interrupt context and task context.
*/
uint32_t task_send_msg(task_id_t tskid, task_id_t from, int wait);
/**
* Return the identifier of the task currently running
*
* when called in interrupt context, returns TASK_ID_INVALID
*/
task_id_t task_get_current(void);
/**
* Return a pointer to the bitmap of received events of the task.
*/
uint32_t *task_get_event_bitmap(task_id_t tsk);
/**
* Waits for the incoming next message.
*
* if an event is already pending, it returns it immediatly, else it
* de-schedules the calling task and wake up the next one in the priority order
*
* if timeout_us > 0, it also sets a timer to produce an event after the
* specified micro-second duration.
*
* returns the bitmap of received events (and clear it atomically).
*/
uint32_t task_wait_msg(int timeout_us);
/**
* Changes the task scheduled after returning from the exception.
*
* If task_send_msg has been called and has set need_resched flag,
* we re-compute which task is running and eventually swap the context
* saved on the process stack to restore the new one at exception exit.
*
* it must be called from interrupt context !
* and it is designed to be the last call of the interrupt handler.
*/
void task_resched_if_needed(void *excep_return);
/* Initializes tasks and interrupt controller. */
int task_init(void);
/* Starts task scheduling. */
int task_start(void);
/* Enables an interrupt. */
void task_enable_irq(int irq);
/* Disables an interrupt. */
void task_disable_irq(int irq);
/* Software-triggers an interrupt. */
void task_trigger_irq(int irq);
struct irq_priority {
uint8_t irq;
uint8_t priority;
};
/**
* Connects the interrupt handler "routine" to the irq number "irq" and
* ensures it is enabled in the interrupt controller with the right priority.
*
* Note that you MUST pass irq as the number ("5") not as a #defined constant,
* because it's stringized and matched up with a weak reference from init.S.
* TODO: fix that; it's typo-prone.
*/
#define DECLARE_IRQ(irq, routine, priority) \
void irq_##irq##_handler(void) \
{ \
void *ret = __builtin_return_address(0); \
routine(); \
task_resched_if_needed(ret); \
} \
const struct irq_priority prio_##irq \
__attribute__((section(".rodata.irqprio"))) \
= {irq, priority}
#endif /* __EC_TASK_H */