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/**
* Copyright © 2017 IBM Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "gpio.hpp"
#include <fcntl.h>
#include <sys/ioctl.h>
#include <cassert>
#include <phosphor-logging/log.hpp>
namespace phosphor
{
namespace gpio
{
using namespace phosphor::logging;
void GPIO::set(Value value)
{
assert(direction == Direction::output);
requestLine(value);
gpiohandle_data data{};
data.values[0] = static_cast<gpioValue_t>(value);
auto rc = ioctl(lineFD(), GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data);
if (rc == -1)
{
auto e = errno;
log<level::ERR>("Failed SET_LINE_VALUES ioctl", entry("ERRNO=%d", e));
throw std::runtime_error("Failed SET_LINE_VALUES ioctl");
}
}
void GPIO::requestLine(Value defaultValue)
{
// Only need to do this once
if (lineFD)
{
return;
}
FileDescriptor fd{open(device.c_str(), 0)};
if (fd() == -1)
{
auto e = errno;
log<level::ERR>("Failed opening GPIO device",
entry("DEVICE=%s", device.c_str()),
entry("ERRNO=%d", e));
throw std::runtime_error("Failed opening GPIO device");
}
// Make an ioctl call to request the GPIO line, which will
// return the descriptor to use to access it.
gpiohandle_request request{};
strncpy(request.consumer_label, "phosphor-gpio-util",
sizeof(request.consumer_label));
request.flags = (direction == Direction::output) ? GPIOHANDLE_REQUEST_OUTPUT
: GPIOHANDLE_REQUEST_INPUT;
request.lineoffsets[0] = gpio;
request.lines = 1;
if (direction == Direction::output)
{
request.default_values[0] = static_cast<gpioValue_t>(defaultValue);
}
auto rc = ioctl(fd(), GPIO_GET_LINEHANDLE_IOCTL, &request);
if (rc == -1)
{
auto e = errno;
log<level::ERR>("Failed GET_LINEHANDLE ioctl", entry("GPIO=%d", gpio),
entry("ERRNO=%d", e));
throw std::runtime_error("Failed GET_LINEHANDLE ioctl");
}
lineFD.set(request.fd);
}
} // namespace gpio
} // namespace phosphor
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