regulators: Add pmbus_write_vout_command action
Implement the pmbus_write_vout_command action in the JSON config file.
See pmbus_write_vout_command.md for more information about this action.
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: Idef8da56d19df8a416efec068ffa9fb9493100cc
diff --git a/phosphor-regulators/src/actions/pmbus_write_vout_command_action.cpp b/phosphor-regulators/src/actions/pmbus_write_vout_command_action.cpp
new file mode 100644
index 0000000..ae5ac4d
--- /dev/null
+++ b/phosphor-regulators/src/actions/pmbus_write_vout_command_action.cpp
@@ -0,0 +1,167 @@
+/**
+ * Copyright © 2020 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 "pmbus_write_vout_command_action.hpp"
+
+#include "action_error.hpp"
+#include "pmbus_error.hpp"
+#include "write_verification_error.hpp"
+
+#include <exception>
+#include <ios>
+#include <sstream>
+
+namespace phosphor::power::regulators
+{
+
+bool PMBusWriteVoutCommandAction::execute(ActionEnvironment& environment)
+{
+ try
+ {
+ // Get volts value
+ double voltsValue = getVoltsValue(environment);
+
+ // Get I2C interface to current device
+ i2c::I2CInterface& interface = getI2CInterface(environment);
+
+ // Get exponent value for converting volts value to linear format
+ int8_t exponentValue = getExponentValue(interface);
+
+ // Convert volts value to linear data format
+ uint16_t linearValue =
+ pmbus_utils::convertToVoutLinear(voltsValue, exponentValue);
+
+ // Write linear format value to VOUT_COMMAND. I2CInterface method
+ // writes low-order byte first as required by PMBus.
+ interface.write(pmbus_utils::VOUT_COMMAND, linearValue);
+
+ // Verify write if necessary
+ if (isWriteVerified)
+ {
+ verifyWrite(environment, interface, linearValue);
+ }
+ }
+ // Nest the following exception types within an ActionError so the caller
+ // will have both the low level error information and the action information
+ catch (const i2c::I2CException& i2cError)
+ {
+ std::throw_with_nested(ActionError(*this));
+ }
+ catch (const PMBusError& pmbusError)
+ {
+ std::throw_with_nested(ActionError(*this));
+ }
+ catch (const WriteVerificationError& verifyError)
+ {
+ std::throw_with_nested(ActionError(*this));
+ }
+ return true;
+}
+
+std::string PMBusWriteVoutCommandAction::toString() const
+{
+ std::ostringstream ss;
+ ss << "pmbus_write_vout_command: { ";
+
+ if (volts.has_value())
+ {
+ ss << "volts: " << volts.value() << ", ";
+ }
+
+ // Only linear format is currently supported
+ ss << "format: linear";
+
+ if (exponent.has_value())
+ {
+ ss << ", exponent: " << static_cast<int16_t>(exponent.value());
+ }
+
+ ss << ", is_verified: " << std::boolalpha << isWriteVerified << " }";
+ return ss.str();
+}
+
+int8_t
+ PMBusWriteVoutCommandAction::getExponentValue(i2c::I2CInterface& interface)
+{
+ // Check if an exponent value is defined for this action
+ if (exponent.has_value())
+ {
+ return exponent.value();
+ }
+
+ // Read value of the VOUT_MODE command
+ uint8_t voutModeValue;
+ interface.read(pmbus_utils::VOUT_MODE, voutModeValue);
+
+ // Parse VOUT_MODE value to get data format and parameter value
+ pmbus_utils::VoutDataFormat format;
+ int8_t parameter;
+ pmbus_utils::parseVoutMode(voutModeValue, format, parameter);
+
+ // Verify format is linear; other formats not currently supported
+ if (format != pmbus_utils::VoutDataFormat::linear)
+ {
+ throw PMBusError("VOUT_MODE contains unsupported data format");
+ }
+
+ // Return parameter value; it contains the exponent when format is linear
+ return parameter;
+}
+
+double
+ PMBusWriteVoutCommandAction::getVoltsValue(ActionEnvironment& environment)
+{
+ double voltsValue;
+
+ if (volts.has_value())
+ {
+ // A volts value is defined for this action
+ voltsValue = volts.value();
+ }
+ else if (environment.hasVolts())
+ {
+ // A volts value is defined in the ActionEnvironment
+ voltsValue = environment.getVolts();
+ }
+ else
+ {
+ throw ActionError(*this, "No volts value defined");
+ }
+
+ return voltsValue;
+}
+
+void PMBusWriteVoutCommandAction::verifyWrite(ActionEnvironment& environment,
+ i2c::I2CInterface& interface,
+ uint16_t valueWritten)
+{
+ // Read current value of VOUT_COMMAND. I2CInterface method reads low byte
+ // first as required by PMBus.
+ uint16_t valueRead{0x00};
+ interface.read(pmbus_utils::VOUT_COMMAND, valueRead);
+
+ // Verify value read equals value written
+ if (valueRead != valueWritten)
+ {
+ std::ostringstream ss;
+ ss << "device: " << environment.getDeviceID()
+ << ", register: VOUT_COMMAND, value_written: 0x" << std::hex
+ << std::uppercase << valueWritten << ", value_read: 0x" << valueRead;
+ throw WriteVerificationError(ss.str());
+ }
+}
+
+} // namespace phosphor::power::regulators