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
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
@@ -0,0 +1,139 @@
+/**
+ * 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
diff --git a/phosphor-regulators/src/meson.build b/phosphor-regulators/src/meson.build
index 2cc8347..b5bb9f4 100644
--- a/phosphor-regulators/src/meson.build
+++ b/phosphor-regulators/src/meson.build
@@ -9,7 +9,8 @@
'actions/if_action.cpp',
'actions/i2c_compare_bit_action.cpp',
'actions/i2c_compare_byte_action.cpp',
- 'actions/i2c_compare_bytes_action.cpp'
+ 'actions/i2c_compare_bytes_action.cpp',
+ 'actions/i2c_write_byte_action.cpp'
]
phosphor_regulators_library = static_library(