lib/firmware/servo_lib.py

# -*- coding: utf-8 -*-
# Copyright 2020 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Servo-related functionality."""

from __future__ import print_function


SERVO_C2D2 = 'c2d2'
SERVO_CCD_CR50 = 'ccd_cr50'
SERVO_MICRO = 'servo_micro'
SERVO_V2 = 'servo_v2'
SERVO_V4_CCD = 'servo_v4_with_ccd_cr50'
SERVO_V4_MICRO = 'servo_v4_with_servo_micro'

VALID_SERVOS = (
    SERVO_C2D2,
    SERVO_CCD_CR50,
    SERVO_MICRO,
    SERVO_V2,
    SERVO_V4_CCD,
    SERVO_V4_MICRO,
)

CCD_SERVOS = (SERVO_CCD_CR50, SERVO_V4_CCD)
MICRO_SERVOS = (SERVO_MICRO, SERVO_V4_MICRO)
V2_SERVOS = (SERVO_V2,)
V4_SERVOS = (SERVO_V4_CCD, SERVO_V4_MICRO)

_SERIAL_NUMBER_OPTION = 'serialname'
_SERIAL_NUMBER_OPTION_OVERRIDE = {
    SERVO_V4_CCD: 'ccd_serialname',
    SERVO_V4_MICRO: 'servo_micro_serialname',
}


class Error(Exception):
  """Base error class for the module."""


class InvalidServoVersion(Error):
  """Invalid servo version error."""


def get(dut_ctl):
  """Get the Servo instance the given dut_control command is using.

  Args:
    dut_ctl (flash_ap.DutControl): The dut_control command wrapper instance.
  """
  version = dut_ctl.get_value('servo_type')
  if version not in VALID_SERVOS:
    raise InvalidServoVersion('Unrecognized servo version: %s' % version)

  option = _SERIAL_NUMBER_OPTION_OVERRIDE.get(version, _SERIAL_NUMBER_OPTION)
  serial = dut_ctl.get_value(option)
  return Servo(version, serial)


class Servo(object):
  """Data class for servos."""

  def __init__(self, version, serial):
    assert version in VALID_SERVOS
    self.version = version
    self.serial = serial

  @property
  def is_ccd(self):
    return self.version in CCD_SERVOS

  @property
  def is_c2d2(self):
    return self.version == SERVO_C2D2

  @property
  def is_micro(self):
    return self.version in MICRO_SERVOS

  @property
  def is_v2(self):
    return self.version in V2_SERVOS

  @property
  def is_v4(self):
    return self.version in V4_SERVOS