ardupilot/libraries/AP_HAL_QURT/DeviceBus.cpp

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

134 lines
4.1 KiB
C++
Raw Normal View History

/*
* This file is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This file is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "DeviceBus.h"
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/utility/OwnPtr.h>
#include <stdio.h>
#include "Scheduler.h"
#include "Semaphores.h"
using namespace QURT;
extern const AP_HAL::HAL& hal;
DeviceBus::DeviceBus(AP_HAL::Scheduler::priority_base _thread_priority) :
thread_priority(_thread_priority), semaphore()
{
}
/*
per-bus callback thread
*/
void DeviceBus::bus_thread(void)
{
while (true) {
uint64_t now = AP_HAL::micros64();
DeviceBus::callback_info *callback;
// find a callback to run
for (callback = callbacks; callback; callback = callback->next) {
if (now >= callback->next_usec) {
while (now >= callback->next_usec) {
callback->next_usec += callback->period_usec;
}
// call it with semaphore held
WITH_SEMAPHORE(semaphore);
callback->cb();
}
}
// work out when next loop is needed
uint64_t next_needed = 0;
now = AP_HAL::micros64();
for (callback = callbacks; callback; callback = callback->next) {
if (next_needed == 0 ||
callback->next_usec < next_needed) {
next_needed = callback->next_usec;
if (next_needed < now) {
next_needed = now;
}
}
}
// delay for at most 50ms, to handle newly added callbacks
uint32_t delay = 50000;
if (next_needed >= now && next_needed - now < delay) {
delay = next_needed - now;
}
// don't delay for less than 100usec, so one thread doesn't
// completely dominate the CPU
if (delay < 100) {
delay = 100;
}
hal.scheduler->delay_microseconds(delay);
}
return;
}
AP_HAL::Device::PeriodicHandle DeviceBus::register_periodic_callback(uint32_t period_usec, AP_HAL::Device::PeriodicCb cb, AP_HAL::Device *_hal_device)
{
if (!thread_started) {
thread_started = true;
hal_device = _hal_device;
// setup a name for the thread
char name[30];
switch (hal_device->bus_type()) {
case AP_HAL::Device::BUS_TYPE_I2C:
snprintf(name, sizeof(name), "APM_I2C:%u",
hal_device->bus_num());
break;
case AP_HAL::Device::BUS_TYPE_SPI:
snprintf(name, sizeof(name), "APM_SPI:%u",
hal_device->bus_num());
break;
default:
break;
}
#ifdef BUSDEBUG
printf("%s:%d Thread Start\n", __PRETTY_FUNCTION__, __LINE__);
#endif
hal.scheduler->thread_create(FUNCTOR_BIND_MEMBER(&DeviceBus::bus_thread, void),
name, HAL_QURT_DEVICE_STACK_SIZE, thread_priority, 0);
}
DeviceBus::callback_info *callback = new DeviceBus::callback_info;
if (callback == nullptr) {
return nullptr;
}
callback->cb = cb;
callback->period_usec = period_usec;
callback->next_usec = AP_HAL::micros64() + period_usec;
// add to linked list of callbacks on thread
callback->next = callbacks;
callbacks = callback;
return callback;
}
/*
* Adjust the timer for the next call: it needs to be called from the bus
* thread, otherwise it will race with it
*/
bool DeviceBus::adjust_timer(AP_HAL::Device::PeriodicHandle h, uint32_t period_usec)
{
// TODO: add timer adjustment
return true;
}