pseq: Create Rail class
Create new Rail class for the phosphor-power-sequencer application. The
class contains the properties from the updated JSON config file format.
Create gtests to test all new code.
Change-Id: Ia55fe3fcc85345deefc1d1987ea1a8421baf50c4
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
diff --git a/phosphor-power-sequencer/src/rail.hpp b/phosphor-power-sequencer/src/rail.hpp
new file mode 100644
index 0000000..5445449
--- /dev/null
+++ b/phosphor-power-sequencer/src/rail.hpp
@@ -0,0 +1,209 @@
+/**
+ * Copyright © 2024 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.
+ */
+#pragma once
+
+#include <cstdint>
+#include <optional>
+#include <stdexcept>
+#include <string>
+
+namespace phosphor::power::sequencer
+{
+
+/**
+ * @struct GPIO
+ *
+ * General Purpose Input/Output (GPIO) that can be read to obtain the pgood
+ * status of a voltage rail.
+ */
+struct GPIO
+{
+ /**
+ * The libgpiod line offset of the GPIO.
+ */
+ unsigned int line{0};
+
+ /**
+ * Specifies whether the GPIO is active low.
+ *
+ * If true, the GPIO value 0 indicates a true pgood status. If false, the
+ * GPIO value 1 indicates a true pgood status.
+ */
+ bool activeLow{false};
+};
+
+/**
+ * @class Rail
+ *
+ * A voltage rail that is enabled or monitored by the power sequencer device.
+ */
+class Rail
+{
+ public:
+ // Specify which compiler-generated methods we want
+ Rail() = delete;
+ Rail(const Rail&) = delete;
+ Rail(Rail&&) = delete;
+ Rail& operator=(const Rail&) = delete;
+ Rail& operator=(Rail&&) = delete;
+ ~Rail() = default;
+
+ /**
+ * Constructor.
+ *
+ * Throws an exception if any of the input parameters are invalid.
+ *
+ * @param name Unique name for the rail
+ * @param presence Optional D-Bus inventory path of a system component which
+ * must be present in order for the rail to be present
+ * @param page Optional PMBus PAGE number of the rail. Required if
+ * checkStatusVout or compareVoltageToLimits is true.
+ * @param checkStatusVout Specifies whether to check the value of the PMBus
+ * STATUS_VOUT command when determining the pgood
+ * status of the rail
+ * @param compareVoltageToLimits Specifies whether to compare the output
+ * voltage to the undervoltage and
+ * overvoltage limits when determining the
+ * pgood status of the rail
+ * @param gpio Optional GPIO to read to determine the pgood status of the
+ * rail
+ */
+ explicit Rail(const std::string& name,
+ const std::optional<std::string>& presence,
+ const std::optional<uint8_t>& page, bool checkStatusVout,
+ bool compareVoltageToLimits,
+ const std::optional<GPIO>& gpio) :
+ name{name},
+ presence{presence}, page{page}, checkStatusVout{checkStatusVout},
+ compareVoltageToLimits{compareVoltageToLimits}, gpio{gpio}
+ {
+ // If checking STATUS_VOUT or output voltage, verify PAGE was specified
+ if ((checkStatusVout || compareVoltageToLimits) && !page.has_value())
+ {
+ throw std::invalid_argument{"PMBus PAGE is required"};
+ }
+ }
+
+ /**
+ * Returns the unique name for the rail.
+ *
+ * @return rail name
+ */
+ const std::string& getName() const
+ {
+ return name;
+ }
+
+ /**
+ * Returns the D-Bus inventory path of a system component which must be
+ * present in order for the rail to be present.
+ *
+ * @return inventory path for presence detection
+ */
+ const std::optional<std::string>& getPresence() const
+ {
+ return presence;
+ }
+
+ /**
+ * Returns the PMBus PAGE number of the rail.
+ *
+ * @return PAGE number for rail
+ */
+ const std::optional<uint8_t>& getPage() const
+ {
+ return page;
+ }
+
+ /**
+ * Returns whether the value of the PMBus STATUS_VOUT command is checked
+ * when determining the pgood status of the rail.
+ *
+ * @return true if STATUS_VOUT is checked, false otherwise
+ */
+ bool getCheckStatusVout() const
+ {
+ return checkStatusVout;
+ }
+
+ /**
+ * Returns whether the output voltage should be compared to the undervoltage
+ * and overvoltage limits when determining the pgood status of the rail.
+ *
+ * @return true if output voltage is compared to limits, false otherwise
+ */
+ bool getCompareVoltageToLimits() const
+ {
+ return compareVoltageToLimits;
+ }
+
+ /**
+ * Returns the GPIO to read to determine the pgood status of the rail.
+ *
+ * @return GPIO
+ */
+ const std::optional<GPIO>& getGPIO() const
+ {
+ return gpio;
+ }
+
+ private:
+ /**
+ * Unique name for the rail.
+ */
+ std::string name{};
+
+ /**
+ * D-Bus inventory path of a system component which must be present in order
+ * for the rail to be present.
+ *
+ * If not specified, the rail is assumed to always be present.
+ */
+ std::optional<std::string> presence{};
+
+ /**
+ * PMBus PAGE number of the rail.
+ */
+ std::optional<uint8_t> page{};
+
+ /**
+ * Specifies whether to check the value of the PMBus STATUS_VOUT command
+ * when determining the pgood status of the rail.
+ *
+ * If one of the error bits is set in STATUS_VOUT, the rail pgood will be
+ * considered false.
+ */
+ bool checkStatusVout{false};
+
+ /**
+ * Specifies whether to compare the output voltage to the undervoltage and
+ * overvoltage limits when determining the pgood status of the rail.
+ *
+ * If the output voltage is beyond those limits, the rail pgood will be
+ * considered false.
+ *
+ * Uses the values of the PMBus READ_VOUT, VOUT_UV_FAULT_LIMIT, and
+ * VOUT_OV_FAULT_LIMIT commands.
+ */
+ bool compareVoltageToLimits{false};
+
+ /**
+ * GPIO to read to determine the pgood status of the rail.
+ */
+ std::optional<GPIO> gpio{};
+};
+
+} // namespace phosphor::power::sequencer