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.hpp b/phosphor-regulators/src/actions/i2c_write_byte_action.hpp
new file mode 100644
index 0000000..99ea154
--- /dev/null
+++ b/phosphor-regulators/src/actions/i2c_write_byte_action.hpp
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+/**
+ * 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.
+ */
+#pragma once
+
+#include "action_environment.hpp"
+#include "i2c_action.hpp"
+
+#include <cstdint>
+#include <string>
+
+namespace phosphor::power::regulators
+{
+
+/**
+ * @class I2CWriteByteAction
+ *
+ * Writes a byte to a device register. Communicates with the device directly
+ * using the I2C interface.
+ *
+ * Implements the i2c_write_byte action in the JSON config file.
+ */
+class I2CWriteByteAction : public I2CAction
+{
+ public:
+ // Specify which compiler-generated methods we want
+ I2CWriteByteAction() = delete;
+ I2CWriteByteAction(const I2CWriteByteAction&) = delete;
+ I2CWriteByteAction(I2CWriteByteAction&&) = delete;
+ I2CWriteByteAction& operator=(const I2CWriteByteAction&) = delete;
+ I2CWriteByteAction& operator=(I2CWriteByteAction&&) = delete;
+ virtual ~I2CWriteByteAction() = default;
+
+ /**
+ * Constructor.
+ *
+ * @param reg Device register address. Note: named 'reg' because 'register'
+ * is a reserved keyword.
+ * @param value Byte value to write.
+ * @param mask Bit mask. Specifies which bits to write within the byte
+ * value. Only the bits with a value of 1 in the mask will be
+ * written.
+ */
+ explicit I2CWriteByteAction(uint8_t reg, uint8_t value,
+ uint8_t mask = 0xFF) :
+ reg{reg},
+ value{value}, mask{mask}
+ {
+ }
+
+ /**
+ * Executes this action.
+ *
+ * Writes a byte to a device register using the I2C interface.
+ *
+ * The device register, byte value, and mask (if any) were specified in the
+ * constructor.
+ *
+ * The device is obtained from the specified action environment.
+ *
+ * Throws an exception if an error occurs.
+ *
+ * @param environment action execution environment
+ * @return true
+ */
+ virtual bool execute(ActionEnvironment& environment) override;
+
+ /**
+ * Returns the device register address.
+ *
+ * @return register address
+ */
+ uint8_t getRegister() const
+ {
+ return reg;
+ }
+
+ /**
+ * Returns the byte value to write.
+ *
+ * @return value to write
+ */
+ uint8_t getValue() const
+ {
+ return value;
+ }
+
+ /**
+ * Returns the bit mask.
+ *
+ * Specifies which bits to write within the byte value. Only the bits with
+ * a value of 1 in the mask will be written.
+ *
+ * @return bit mask
+ */
+ uint8_t getMask() const
+ {
+ return mask;
+ }
+
+ /**
+ * Returns a string description of this action.
+ *
+ * @return description of action
+ */
+ virtual std::string toString() const override;
+
+ private:
+ /**
+ * Device register address. Note: named 'reg' because 'register' is a
+ * reserved keyword.
+ */
+ const uint8_t reg{0x00};
+
+ /**
+ * Byte value to write.
+ */
+ const uint8_t value{0x00};
+
+ /**
+ * Bit mask. Specifies which bits to write within the byte value. Only the
+ * bits with a value of 1 in the mask will be written.
+ */
+ const uint8_t mask{0xFF};
+};
+
+} // namespace phosphor::power::regulators