/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file device.cpp
*
* Fundamental driver base class for the device framework.
*/
#include "device.h"
#include <nuttx/arch.h>
#include <stdio.h>
#include <unistd.h>
namespace device
{
/**
* Interrupt dispatch table entry.
*/
struct irq_entry {
int irq;
Device *owner;
};
static const unsigned irq_nentries = 8; /**< size of the interrupt dispatch table */
static irq_entry irq_entries[irq_nentries]; /**< interrupt dispatch table (XXX should be a vector) */
/**
* Register an interrupt to a specific device.
*
* @param irq The interrupt number to register.
* @param owner The device receiving the interrupt.
* @return OK if the interrupt was registered.
*/
static int register_interrupt(int irq, Device *owner);
/**
* Unregister an interrupt.
*
* @param irq The previously-registered interrupt to be de-registered.
*/
static void unregister_interrupt(int irq);
/**
* Handle an interrupt.
*
* @param irq The interrupt being invoked.
* @param context The interrupt register context.
* @return Always returns OK.
*/
static int interrupt(int irq, void *context);
Device::Device(const char *name,
int irq) :
// public
// protected
_name(name),
_debug_enabled(false),
// private
_irq(irq),
_irq_attached(false)
{
sem_init(&_lock, 0, 1);
}
Device::~Device()
{
sem_destroy(&_lock);
if (_irq_attached)
unregister_interrupt(_irq);
}
int
Device::init()
{
int ret = OK;
// If assigned an interrupt, connect it
if (_irq) {
/* ensure it's disabled */
up_disable_irq(_irq);
/* register */
ret = register_interrupt(_irq, this);
if (ret != OK)
goto out;
_irq_attached = true;
}
out:
return ret;
}
void
Device::interrupt_enable()
{
if (_irq_attached)
up_enable_irq(_irq);
}
void
Device::interrupt_disable()
{
if (_irq_attached)
up_disable_irq(_irq);
}
void
Device::interrupt(void *context)
{
// default action is to disable the interrupt so we don't get called again
interrupt_disable();
}
void
Device::log(const char *fmt, ...)
{
va_list ap;
printf("[%s] ", _name);
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
printf("\n");
fflush(stdout);
}
void
Device::debug(const char *fmt, ...)
{
va_list ap;
if (_debug_enabled) {
printf("<%s> ", _name);
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
printf("\n");
fflush(stdout);
}
}
static int
register_interrupt(int irq, Device *owner)
{
int ret = -ENOMEM;
// look for a slot where we can register the interrupt
for (unsigned i = 0; i < irq_nentries; i++) {
if (irq_entries[i].irq == 0) {
// great, we could put it here; try attaching it
ret = irq_attach(irq, &interrupt);
if (ret == OK) {
irq_entries[i].irq = irq;
irq_entries[i].owner = owner;
}
break;
}
}
return ret;
}
static void
unregister_interrupt(int irq)
{
for (unsigned i = 0; i < irq_nentries; i++) {
if (irq_entries[i].irq == irq) {
irq_entries[i].irq = 0;
irq_entries[i].owner = nullptr;
}
}
}
static int
interrupt(int irq, void *context)
{
for (unsigned i = 0; i < irq_nentries; i++) {
if (irq_entries[i].irq == irq) {
irq_entries[i].owner->interrupt(context);
break;
}
}
return OK;
}
int
Device::read(unsigned offset, void *data, unsigned count)
{
return -ENODEV;
}
int
Device::write(unsigned offset, void *data, unsigned count)
{
return -ENODEV;
}
int
Device::ioctl(unsigned operation, unsigned &arg)
{
return -ENODEV;
}
} // namespace device
