pmbus.hpp - openbmc/phosphor-power - Gitiles

 #pragma once

 #include <filesystem>
 #include <string>
 #include <vector>

 namespace phosphor
 {
 namespace pmbus
 {

 namespace fs = std::filesystem;

 // The file name Linux uses to capture the READ_VIN from pmbus.
 constexpr auto READ_VIN = "in1_input";

 namespace in_input
 {
 // VIN thresholds in Volts
 constexpr auto VIN_VOLTAGE_MIN = 20;
 constexpr auto VIN_VOLTAGE_110_THRESHOLD = 160;

 // VIN actual values in Volts
 // VIN_VOLTAGE_0:   VIN < VIN_VOLTAGE_MIN
 // VIN_VOLTAGE_110: VIN_VOLTAGE_MIN < VIN < VIN_VOLTAGE_110_THRESHOLD
 // VIN_VOLTAGE_220: VIN_VOLTAGE_110_THRESHOLD < VIN
 constexpr auto VIN_VOLTAGE_0 = 0;
 constexpr auto VIN_VOLTAGE_110 = 110;
 constexpr auto VIN_VOLTAGE_220 = 220;
 } // namespace in_input

 // The file name Linux uses to capture the STATUS_WORD from pmbus.
 constexpr auto STATUS_WORD = "status0";

 // The file name Linux uses to capture the STATUS_INPUT from pmbus.
 constexpr auto STATUS_INPUT = "status0_input";

 // Voltage out status.
 // Overvoltage fault or warning, Undervoltage fault or warning, maximum or
 // minimum warning, ....
 // Uses Page substitution
 constexpr auto STATUS_VOUT = "statusP_vout";

 namespace status_vout
 {
 // Mask of bits that are only warnings
 constexpr auto WARNING_MASK = 0x6A;
 } // namespace status_vout

 // Current output status bits.
 constexpr auto STATUS_IOUT = "status0_iout";

 // Manufacturing specific status bits
 constexpr auto STATUS_MFR = "status0_mfr";

 // Reports on the status of any fans installed in position 1 and 2.
 constexpr auto STATUS_FANS_1_2 = "status0_fan12";

 // Reports on temperature faults or warnings. Overtemperature fault,
 // overtemperature warning, undertemperature warning, undertemperature fault.
 constexpr auto STATUS_TEMPERATURE = "status0_temp";

 // Reports on the communication, memory, logic fault(s).
 constexpr auto STATUS_CML = "status0_cml";

 namespace status_word
 {
 constexpr auto VOUT_FAULT = 0x8000;

 // The IBM CFF power supply driver does map this bit to power1_alarm in the
 // hwmon space, but since the other bits that need to be checked do not have
 // a similar mapping, the code will just read STATUS_WORD and use bit masking
 // to see if the INPUT FAULT OR WARNING bit is on.
 constexpr auto INPUT_FAULT_WARN = 0x2000;

 // The bit mask representing the MFRSPECIFIC fault, bit 4 of STATUS_WORD high
 // byte. A manufacturer specific fault or warning has occurred.
 constexpr auto MFR_SPECIFIC_FAULT = 0x1000;

 // The bit mask representing the POWER_GOOD Negated bit of the STATUS_WORD.
 constexpr auto POWER_GOOD_NEGATED = 0x0800;

 // The bit mask representing the FAN FAULT or WARNING bit of the STATUS_WORD.
 // Bit 2 of the high byte of STATUS_WORD.
 constexpr auto FAN_FAULT = 0x0400;

 // The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD.
 constexpr auto UNIT_IS_OFF = 0x0040;

 // Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate
 // an output overvoltage fault.
 constexpr auto VOUT_OV_FAULT = 0x0020;

 // The bit mask representing that an output overcurrent fault has occurred.
 constexpr auto IOUT_OC_FAULT = 0x0010;

 // The IBM CFF power supply driver does map this bit to in1_alarm, however,
 // since a number of the other bits are not mapped that way for STATUS_WORD,
 // this code will just read the entire STATUS_WORD and use bit masking to find
 // out if that fault is on.
 constexpr auto VIN_UV_FAULT = 0x0008;

 // The bit mask representing the TEMPERATURE FAULT or WARNING bit of the
 // STATUS_WORD. Bit 2 of the low byte (STATUS_BYTE).
 constexpr auto TEMPERATURE_FAULT_WARN = 0x0004;

 // The bit mask representing the CML (Communication, Memory, and/or Logic) fault
 // bit of the STATUS_WORD. Bit 1 of the low byte (STATUS_BYTE).
 constexpr auto CML_FAULT = 0x0002;
 } // namespace status_word

 namespace status_vout
 {
 // The IBM CFF power supply driver maps MFR's OV_FAULT and VAUX_FAULT to this
 // bit.
 constexpr auto OV_FAULT = 0x80;

 // The IBM CFF power supply driver maps MFR's UV_FAULT to this bit.
 constexpr auto UV_FAULT = 0x10;
 } // namespace status_vout

 namespace status_temperature
 {
 // Overtemperature Fault
 constexpr auto OT_FAULT = 0x80;
 } // namespace status_temperature

 constexpr auto ON_OFF_CONFIG = "on_off_config";

 // From PMBus Specification Part II Revsion 1.2:
 // The ON_OFF_CONFIG command configures the combination of CONTROL pin input
 // and serial bus commands needed to turn the unit on and off. This includes how
 // the unit responds when power is applied.
 // Bits [7:5] - 000 - Reserved
 // Bit 4 - 1 - Unit does not power up until commanded by the CONTROL pin and
 // OPERATION command (as programmed in bits [3:0]).
 // Bit 3 - 0 - Unit ignores the on/off portion of the OPERATION command from
 // serial bus.
 // Bit 2 - 1 - Unit requires the CONTROL pin to be asserted to start the unit.
 // Bit 1 - 0 - Polarity of the CONTROL pin. Active low (Pull pin low to start
 // the unit).
 // Bit 0 - 1 - Turn off the output and stop transferring energy to the output as
 // fast as possible.
 constexpr auto ON_OFF_CONFIG_CONTROL_PIN_ONLY = 0x15;

 /**
  * Where the access should be done
  */
 enum class Type
 {
     Base,            // base device directory
     Hwmon,           // hwmon directory
     Debug,           // pmbus debug directory
     DeviceDebug,     // device debug directory
     HwmonDeviceDebug // hwmon device debug directory
 };

 /**
  * @class PMBusBase
  *
  * This is a base class for PMBus to assist with unit testing via mocking.
  */
 class PMBusBase
 {
   public:
     virtual ~PMBusBase() = default;

     virtual uint64_t read(const std::string& name, Type type) = 0;
     virtual std::string readString(const std::string& name, Type type) = 0;
     virtual void writeBinary(const std::string& name, std::vector<uint8_t> data,
                              Type type) = 0;
     virtual void findHwmonDir() = 0;
     virtual const fs::path& path() const = 0;
     virtual std::string insertPageNum(const std::string& templateName,
                                       size_t page) = 0;
 };

 /**
  * Wrapper function for PMBus
  *
  * @param[in] bus - I2C bus
  * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
  *
  * @return PMBusBase pointer
  */
 std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
                                        const std::string& address);

 /**
  * @class PMBus
  *
  * This class is an interface to communicating with PMBus devices
  * by reading and writing sysfs files.
  *
  * Based on the Type parameter, the accesses can either be done
  * in the base device directory (the one passed into the constructor),
  * or in the hwmon directory for the device.
  */
 class PMBus : public PMBusBase
 {
   public:
     PMBus() = delete;
     virtual ~PMBus() = default;
     PMBus(const PMBus&) = default;
     PMBus& operator=(const PMBus&) = default;
     PMBus(PMBus&&) = default;
     PMBus& operator=(PMBus&&) = default;

     /**
      * Constructor
      *
      * @param[in] path - path to the sysfs directory
      */
     PMBus(const std::string& path) : basePath(path)
     {
         findHwmonDir();
     }

     /**
      * Constructor
      *
      * This version is required when DeviceDebug
      * access will be used.
      *
      * @param[in] path - path to the sysfs directory
      * @param[in] driverName - the device driver name
      * @param[in] instance - chip instance number
      */
     PMBus(const std::string& path, const std::string& driverName,
           size_t instance) :
         basePath(path),
         driverName(driverName), instance(instance)
     {
         findHwmonDir();
     }

     /**
      * Wrapper function for PMBus
      *
      * @param[in] bus - I2C bus
      * @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
      *
      * @return PMBusBase pointer
      */
     static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
                                                   const std::string& address);

     /**
      * Reads a file in sysfs that represents a single bit,
      * therefore doing a PMBus read.
      *
      * @param[in] name - path concatenated to
      *                   basePath to read
      * @param[in] type - Path type
      *
      * @return bool - false if result was 0, else true
      */
     bool readBit(const std::string& name, Type type);

     /**
      * Reads a file in sysfs that represents a single bit,
      * where the page number passed in is substituted
      * into the name in place of the 'P' character in it.
      *
      * @param[in] name - path concatenated to
      *                   basePath to read
      * @param[in] page - page number
      * @param[in] type - Path type
      *
      * @return bool - false if result was 0, else true
      */
     bool readBitInPage(const std::string& name, size_t page, Type type);
     /**
      * Checks if the file for the given name and type exists.
      *
      * @param[in] name   - path concatenated to basePath to read
      * @param[in] type   - Path type
      *
      * @return bool - True if file exists, false if it does not.
      */
     bool exists(const std::string& name, Type type);

     /**
      * Read byte(s) from file in sysfs.
      *
      * @param[in] name   - path concatenated to basePath to read
      * @param[in] type   - Path type
      *
      * @return uint64_t - Up to 8 bytes of data read from file.
      */
     uint64_t read(const std::string& name, Type type) override;

     /**
      * Read a string from file in sysfs.
      *
      * @param[in] name   - path concatenated to basePath to read
      * @param[in] type   - Path type
      *
      * @return string - The data read from the file.
      */
     std::string readString(const std::string& name, Type type) override;

     /**
      * Read data from a binary file in sysfs.
      *
      * @param[in] name   - path concatenated to basePath to read
      * @param[in] type   - Path type
      * @param[in] length - length of data to read, in bytes
      *
      * @return vector<uint8_t> - The data read from the file.
      */
     std::vector<uint8_t> readBinary(const std::string& name, Type type,
                                     size_t length);

     /**
      * Writes an integer value to the file, therefore doing
      * a PMBus write.
      *
      * @param[in] name - path concatenated to
      *                   basePath to write
      * @param[in] value - the value to write
      * @param[in] type - Path type
      */
     void write(const std::string& name, int value, Type type);

     /**
      * Writes binary data to a file in sysfs.
      *
      * @param[in] name - path concatenated to basePath to write
      * @param[in] data - The data to write to the file
      * @param[in] type - Path type
      */
     void writeBinary(const std::string& name, std::vector<uint8_t> data,
                      Type type) override;

     /**
      * Returns the sysfs base path of this device
      */
     const fs::path& path() const override
     {
         return basePath;
     }

     /**
      * Replaces the 'P' in the string passed in with
      * the page number passed in.
      *
      * For example:
      *   insertPageNum("inP_enable", 42)
      *   returns "in42_enable"
      *
      * @param[in] templateName - the name string, with a 'P' in it
      * @param[in] page - the page number to insert where the P was
      *
      * @return string - the new string with the page number in it
      */
     std::string insertPageNum(const std::string& templateName,
                               size_t page) override;

     /**
      * Finds the path relative to basePath to the hwmon directory
      * for the device and stores it in hwmonRelPath.
      */
     void findHwmonDir() override;

     /**
      * Returns the path to use for the passed in type.
      *
      * @param[in] type - Path type
      *
      * @return fs::path - the full path
      */
     fs::path getPath(Type type);

   private:
     /**
      * Returns the device name
      *
      * This is found in the 'name' file in basePath.
      *
      * @return string - the device name
      */
     std::string getDeviceName();

     /**
      * The sysfs device path
      */
     fs::path basePath;

     /**
      * The directory name under the basePath hwmon directory
      */
     fs::path hwmonDir;

     /**
      * The device driver name.  Used for finding the device
      * debug directory.  Not required if that directory
      * isn't used.
      */
     std::string driverName;

     /**
      * The device instance number.
      *
      * Used in conjunction with the driver name for finding
      * the debug directory.  Not required if that directory
      * isn't used.
      */
     size_t instance = 0;

     /**
      * The pmbus debug path with status files
      */
     const fs::path debugPath = "/sys/kernel/debug/";
 };

 } // namespace pmbus
 } // namespace phosphor
	#pragma once

	#include <filesystem>
	#include <string>
	#include <vector>

	namespace phosphor
	{
	namespace pmbus
	{

	namespace fs = std::filesystem;

	// The file name Linux uses to capture the READ_VIN from pmbus.
	constexpr auto READ_VIN = "in1_input";

	namespace in_input
	{
	// VIN thresholds in Volts
	constexpr auto VIN_VOLTAGE_MIN = 20;
	constexpr auto VIN_VOLTAGE_110_THRESHOLD = 160;

	// VIN actual values in Volts
	// VIN_VOLTAGE_0: VIN < VIN_VOLTAGE_MIN
	// VIN_VOLTAGE_110: VIN_VOLTAGE_MIN < VIN < VIN_VOLTAGE_110_THRESHOLD
	// VIN_VOLTAGE_220: VIN_VOLTAGE_110_THRESHOLD < VIN
	constexpr auto VIN_VOLTAGE_0 = 0;
	constexpr auto VIN_VOLTAGE_110 = 110;
	constexpr auto VIN_VOLTAGE_220 = 220;
	} // namespace in_input

	// The file name Linux uses to capture the STATUS_WORD from pmbus.
	constexpr auto STATUS_WORD = "status0";

	// The file name Linux uses to capture the STATUS_INPUT from pmbus.
	constexpr auto STATUS_INPUT = "status0_input";

	// Voltage out status.
	// Overvoltage fault or warning, Undervoltage fault or warning, maximum or
	// minimum warning, ....
	// Uses Page substitution
	constexpr auto STATUS_VOUT = "statusP_vout";

	namespace status_vout
	{
	// Mask of bits that are only warnings
	constexpr auto WARNING_MASK = 0x6A;
	} // namespace status_vout

	// Current output status bits.
	constexpr auto STATUS_IOUT = "status0_iout";

	// Manufacturing specific status bits
	constexpr auto STATUS_MFR = "status0_mfr";

	// Reports on the status of any fans installed in position 1 and 2.
	constexpr auto STATUS_FANS_1_2 = "status0_fan12";

	// Reports on temperature faults or warnings. Overtemperature fault,
	// overtemperature warning, undertemperature warning, undertemperature fault.
	constexpr auto STATUS_TEMPERATURE = "status0_temp";

	// Reports on the communication, memory, logic fault(s).
	constexpr auto STATUS_CML = "status0_cml";

	namespace status_word
	{
	constexpr auto VOUT_FAULT = 0x8000;

	// The IBM CFF power supply driver does map this bit to power1_alarm in the
	// hwmon space, but since the other bits that need to be checked do not have
	// a similar mapping, the code will just read STATUS_WORD and use bit masking
	// to see if the INPUT FAULT OR WARNING bit is on.
	constexpr auto INPUT_FAULT_WARN = 0x2000;

	// The bit mask representing the MFRSPECIFIC fault, bit 4 of STATUS_WORD high
	// byte. A manufacturer specific fault or warning has occurred.
	constexpr auto MFR_SPECIFIC_FAULT = 0x1000;

	// The bit mask representing the POWER_GOOD Negated bit of the STATUS_WORD.
	constexpr auto POWER_GOOD_NEGATED = 0x0800;

	// The bit mask representing the FAN FAULT or WARNING bit of the STATUS_WORD.
	// Bit 2 of the high byte of STATUS_WORD.
	constexpr auto FAN_FAULT = 0x0400;

	// The bit mask representing the UNITI_IS_OFF bit of the STATUS_WORD.
	constexpr auto UNIT_IS_OFF = 0x0040;

	// Bit 5 of the STATUS_BYTE, or lower byte of STATUS_WORD is used to indicate
	// an output overvoltage fault.
	constexpr auto VOUT_OV_FAULT = 0x0020;

	// The bit mask representing that an output overcurrent fault has occurred.
	constexpr auto IOUT_OC_FAULT = 0x0010;

	// The IBM CFF power supply driver does map this bit to in1_alarm, however,
	// since a number of the other bits are not mapped that way for STATUS_WORD,
	// this code will just read the entire STATUS_WORD and use bit masking to find
	// out if that fault is on.
	constexpr auto VIN_UV_FAULT = 0x0008;

	// The bit mask representing the TEMPERATURE FAULT or WARNING bit of the
	// STATUS_WORD. Bit 2 of the low byte (STATUS_BYTE).
	constexpr auto TEMPERATURE_FAULT_WARN = 0x0004;

	// The bit mask representing the CML (Communication, Memory, and/or Logic) fault
	// bit of the STATUS_WORD. Bit 1 of the low byte (STATUS_BYTE).
	constexpr auto CML_FAULT = 0x0002;
	} // namespace status_word

	namespace status_vout
	{
	// The IBM CFF power supply driver maps MFR's OV_FAULT and VAUX_FAULT to this
	// bit.
	constexpr auto OV_FAULT = 0x80;

	// The IBM CFF power supply driver maps MFR's UV_FAULT to this bit.
	constexpr auto UV_FAULT = 0x10;
	} // namespace status_vout

	namespace status_temperature
	{
	// Overtemperature Fault
	constexpr auto OT_FAULT = 0x80;
	} // namespace status_temperature

	constexpr auto ON_OFF_CONFIG = "on_off_config";

	// From PMBus Specification Part II Revsion 1.2:
	// The ON_OFF_CONFIG command configures the combination of CONTROL pin input
	// and serial bus commands needed to turn the unit on and off. This includes how
	// the unit responds when power is applied.
	// Bits [7:5] - 000 - Reserved
	// Bit 4 - 1 - Unit does not power up until commanded by the CONTROL pin and
	// OPERATION command (as programmed in bits [3:0]).
	// Bit 3 - 0 - Unit ignores the on/off portion of the OPERATION command from
	// serial bus.
	// Bit 2 - 1 - Unit requires the CONTROL pin to be asserted to start the unit.
	// Bit 1 - 0 - Polarity of the CONTROL pin. Active low (Pull pin low to start
	// the unit).
	// Bit 0 - 1 - Turn off the output and stop transferring energy to the output as
	// fast as possible.
	constexpr auto ON_OFF_CONFIG_CONTROL_PIN_ONLY = 0x15;

	/**
	* Where the access should be done
	*/
	enum class Type
	{
	Base, // base device directory
	Hwmon, // hwmon directory
	Debug, // pmbus debug directory
	DeviceDebug, // device debug directory
	HwmonDeviceDebug // hwmon device debug directory
	};

	/**
	* @class PMBusBase
	*
	* This is a base class for PMBus to assist with unit testing via mocking.
	*/
	class PMBusBase
	{
	public:
	virtual ~PMBusBase() = default;

	virtual uint64_t read(const std::string& name, Type type) = 0;
	virtual std::string readString(const std::string& name, Type type) = 0;
	virtual void writeBinary(const std::string& name, std::vector<uint8_t> data,
	Type type) = 0;
	virtual void findHwmonDir() = 0;
	virtual const fs::path& path() const = 0;
	virtual std::string insertPageNum(const std::string& templateName,
	size_t page) = 0;
	};

	/**
	* Wrapper function for PMBus
	*
	* @param[in] bus - I2C bus
	* @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
	*
	* @return PMBusBase pointer
	*/
	std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
	const std::string& address);

	/**
	* @class PMBus
	*
	* This class is an interface to communicating with PMBus devices
	* by reading and writing sysfs files.
	*
	* Based on the Type parameter, the accesses can either be done
	* in the base device directory (the one passed into the constructor),
	* or in the hwmon directory for the device.
	*/
	class PMBus : public PMBusBase
	{
	public:
	PMBus() = delete;
	virtual ~PMBus() = default;
	PMBus(const PMBus&) = default;
	PMBus& operator=(const PMBus&) = default;
	PMBus(PMBus&&) = default;
	PMBus& operator=(PMBus&&) = default;

	/**
	* Constructor
	*
	* @param[in] path - path to the sysfs directory
	*/
	PMBus(const std::string& path) : basePath(path)
	{
	findHwmonDir();
	}

	/**
	* Constructor
	*
	* This version is required when DeviceDebug
	* access will be used.
	*
	* @param[in] path - path to the sysfs directory
	* @param[in] driverName - the device driver name
	* @param[in] instance - chip instance number
	*/
	PMBus(const std::string& path, const std::string& driverName,
	size_t instance) :
	basePath(path),
	driverName(driverName), instance(instance)
	{
	findHwmonDir();
	}

	/**
	* Wrapper function for PMBus
	*
	* @param[in] bus - I2C bus
	* @param[in] address - I2C address (as a 2-byte string, e.g. 0069)
	*
	* @return PMBusBase pointer
	*/
	static std::unique_ptr<PMBusBase> createPMBus(std::uint8_t bus,
	const std::string& address);

	/**
	* Reads a file in sysfs that represents a single bit,
	* therefore doing a PMBus read.
	*
	* @param[in] name - path concatenated to
	* basePath to read
	* @param[in] type - Path type
	*
	* @return bool - false if result was 0, else true
	*/
	bool readBit(const std::string& name, Type type);

	/**
	* Reads a file in sysfs that represents a single bit,
	* where the page number passed in is substituted
	* into the name in place of the 'P' character in it.
	*
	* @param[in] name - path concatenated to
	* basePath to read
	* @param[in] page - page number
	* @param[in] type - Path type
	*
	* @return bool - false if result was 0, else true
	*/
	bool readBitInPage(const std::string& name, size_t page, Type type);
	/**
	* Checks if the file for the given name and type exists.
	*
	* @param[in] name - path concatenated to basePath to read
	* @param[in] type - Path type
	*
	* @return bool - True if file exists, false if it does not.
	*/
	bool exists(const std::string& name, Type type);

	/**
	* Read byte(s) from file in sysfs.
	*
	* @param[in] name - path concatenated to basePath to read
	* @param[in] type - Path type
	*
	* @return uint64_t - Up to 8 bytes of data read from file.
	*/
	uint64_t read(const std::string& name, Type type) override;

	/**
	* Read a string from file in sysfs.
	*
	* @param[in] name - path concatenated to basePath to read
	* @param[in] type - Path type
	*
	* @return string - The data read from the file.
	*/
	std::string readString(const std::string& name, Type type) override;

	/**
	* Read data from a binary file in sysfs.
	*
	* @param[in] name - path concatenated to basePath to read
	* @param[in] type - Path type
	* @param[in] length - length of data to read, in bytes
	*
	* @return vector<uint8_t> - The data read from the file.
	*/
	std::vector<uint8_t> readBinary(const std::string& name, Type type,
	size_t length);

	/**
	* Writes an integer value to the file, therefore doing
	* a PMBus write.
	*
	* @param[in] name - path concatenated to
	* basePath to write
	* @param[in] value - the value to write
	* @param[in] type - Path type
	*/
	void write(const std::string& name, int value, Type type);

	/**
	* Writes binary data to a file in sysfs.
	*
	* @param[in] name - path concatenated to basePath to write
	* @param[in] data - The data to write to the file
	* @param[in] type - Path type
	*/
	void writeBinary(const std::string& name, std::vector<uint8_t> data,
	Type type) override;

	/**
	* Returns the sysfs base path of this device
	*/
	const fs::path& path() const override
	{
	return basePath;
	}

	/**
	* Replaces the 'P' in the string passed in with
	* the page number passed in.
	*
	* For example:
	* insertPageNum("inP_enable", 42)
	* returns "in42_enable"
	*
	* @param[in] templateName - the name string, with a 'P' in it
	* @param[in] page - the page number to insert where the P was
	*
	* @return string - the new string with the page number in it
	*/
	std::string insertPageNum(const std::string& templateName,
	size_t page) override;

	/**
	* Finds the path relative to basePath to the hwmon directory
	* for the device and stores it in hwmonRelPath.
	*/
	void findHwmonDir() override;

	/**
	* Returns the path to use for the passed in type.
	*
	* @param[in] type - Path type
	*
	* @return fs::path - the full path
	*/
	fs::path getPath(Type type);

	private:
	/**
	* Returns the device name
	*
	* This is found in the 'name' file in basePath.
	*
	* @return string - the device name
	*/
	std::string getDeviceName();

	/**
	* The sysfs device path
	*/
	fs::path basePath;

	/**
	* The directory name under the basePath hwmon directory
	*/
	fs::path hwmonDir;

	/**
	* The device driver name. Used for finding the device
	* debug directory. Not required if that directory
	* isn't used.
	*/
	std::string driverName;

	/**
	* The device instance number.
	*
	* Used in conjunction with the driver name for finding
	* the debug directory. Not required if that directory
	* isn't used.
	*/
	size_t instance = 0;

	/**
	* The pmbus debug path with status files
	*/
	const fs::path debugPath = "/sys/kernel/debug/";
	};

	} // namespace pmbus
	} // namespace phosphor