How to change clef and relative note

[Ivanov Dmitry]

I have the following attempt to typeset the waltz:

\version "2.18.2"
upper = \relative c {
  \clef bass
  \key c \minor
  \time 3/4
  \tempo 4 = 170
  r4 \chordmode { c,4:m c,4:m } |
  r4 \chordmode { c,4:m c,4:m } |
  r4 \chordmode { c,4:m c,4:m } |
  r4 \chordmode { c,4:m } r4 |
  \clef violin
  g''2.
}

lower = \relative c {
  \clef bass
  \key c \minor
  \time 3/4

  <c c,>4 r4 r4 |
  <g g,>4 r4 r4 |
  <c c,>4 r4 r4 |
  <g g,>4 r4 \chordmode { c,4:m } |
  c4 <ees g>4 <ees g>4 |
}

\score {
  \new PianoStaff \with { instrumentName = "Piano" }
  <<
    \new Staff = "upper" \upper
    \new Staff = "lower" \lower
  >>
  \layout { }
  \midi { }
}

The difficulty is the I switch from bass to violin clef in the right
hand. Is it possible to change the relative note, so I won't need to
add 2 quotes after each note like I did for g:  g''2?