regulators: Implement i2c_write_byte action
Implement the i2c_write_byte action in the JSON config file. See
i2c_write_byte.md for more information about this action.
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I37fb9b81ee6d9e7fc226787a3242f389b8903714
diff --git a/phosphor-regulators/src/actions/i2c_write_byte_action.cpp b/phosphor-regulators/src/actions/i2c_write_byte_action.cpp
new file mode 100644
index 0000000..2657178
--- /dev/null
+++ b/phosphor-regulators/src/actions/i2c_write_byte_action.cpp
@@ -0,0 +1,71 @@
+/**
+ * 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 "i2c_write_byte_action.hpp"
+
+#include "action_error.hpp"
+#include "i2c_interface.hpp"
+
+#include <exception>
+#include <ios>
+#include <sstream>
+
+namespace phosphor::power::regulators
+{
+
+bool I2CWriteByteAction::execute(ActionEnvironment& environment)
+{
+ try
+ {
+ i2c::I2CInterface& interface = getI2CInterface(environment);
+ uint8_t valueToWrite;
+ if (mask == 0xFF)
+ {
+ valueToWrite = value;
+ }
+ else
+ {
+ // Read current value of device register
+ uint8_t currentValue{0x00};
+ interface.read(reg, currentValue);
+
+ // Combine value to write with current value
+ valueToWrite = (value & mask) | (currentValue & (~mask));
+ }
+
+ // Write value to device register
+ interface.write(reg, valueToWrite);
+ }
+ catch (const i2c::I2CException& e)
+ {
+ // Nest I2CException within an ActionError so caller will have both the
+ // low level I2C error information and the action information
+ std::throw_with_nested(ActionError(*this));
+ }
+ return true;
+}
+
+std::string I2CWriteByteAction::toString() const
+{
+ std::ostringstream ss;
+ ss << "i2c_write_byte: { register: 0x" << std::hex << std::uppercase
+ << static_cast<uint16_t>(reg) << ", value: 0x"
+ << static_cast<uint16_t>(value) << ", mask: 0x"
+ << static_cast<uint16_t>(mask) << " }";
+ return ss.str();
+}
+
+} // namespace phosphor::power::regulators