Add GPIO class
This class will be used for accessing GPIOs off of the
UCD90160 to check for PGOOD faults, and also later for
isolating GPU overtemps and PGOOD faults down to the specific
GPU that failed.
The FileDescriptor class is used by the GPIO class to manage
the lifetime of the GPIO file handles.
The class only supports reading a GPIO value. At this point
there is no requirement for doing writes.
This class was copied from phosphor-gpio-monitor/gpio-util.
Change-Id: Iee276aed67e1cba549c3070c08238ab5f621c320
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/power-sequencer/gpio.cpp b/power-sequencer/gpio.cpp
new file mode 100644
index 0000000..32f4358
--- /dev/null
+++ b/power-sequencer/gpio.cpp
@@ -0,0 +1,103 @@
+/**
+ * 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 <fcntl.h>
+#include <phosphor-logging/elog.hpp>
+#include <phosphor-logging/elog-errors.hpp>
+#include <phosphor-logging/log.hpp>
+#include <sys/ioctl.h>
+#include <xyz/openbmc_project/Common/error.hpp>
+#include "gpio.hpp"
+
+namespace witherspoon
+{
+namespace gpio
+{
+
+using namespace phosphor::logging;
+
+using InternalFailure = sdbusplus::xyz::openbmc_project::Common::
+ Error::InternalFailure;
+
+Value GPIO::read()
+{
+ assert(direction == Direction::input);
+
+ requestLine();
+
+ gpiohandle_data data{};
+
+ auto rc = ioctl(lineFD(),
+ GPIOHANDLE_GET_LINE_VALUES_IOCTL,
+ &data);
+
+ if (rc < 0)
+ {
+ auto e = errno;
+ log<level::ERR>("Failed GET_LINE_VALUES ioctl",
+ entry("ERRNO=%d", e));
+ elog<InternalFailure>();
+ }
+
+ return (data.values[0] == 0) ? Value::low : Value::high;
+}
+
+
+void GPIO::requestLine()
+{
+ //Only need to do this once
+ if (lineFD)
+ {
+ return;
+ }
+
+ power::util::FileDescriptor fd{open(device.c_str(), 0)};
+ if (fd() == -1)
+ {
+ auto e = errno;
+ log<level::ERR>("Failed opening GPIO device",
+ entry("DEVICE=%s", device),
+ entry("ERRNO=%d", e));
+ elog<InternalFailure>();
+ }
+
+ //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,
+ "witherspoon-pfault-analysis",
+ sizeof(request.consumer_label));
+
+ request.flags = (direction == Direction::input) ?
+ GPIOHANDLE_REQUEST_INPUT : GPIOHANDLE_REQUEST_OUTPUT;
+
+ request.lineoffsets[0] = gpio;
+ request.lines = 1;
+
+ 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));
+ elog<InternalFailure>();
+ }
+
+ lineFD.set(request.fd);
+}
+
+}
+}