From 'Application Note AN521', chapter 4.7:

  The SMM implements four SBCon serial modules:

  One SBCon module for use by the Color LCD touch interface.
  One SBCon module to configure the audio controller.
  Two general purpose SBCon modules, that connect to the
  Expansion headers J7 and J8, are intended for use with the
  V2C-Shield1 which provide an I2C interface on the headers.
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200617072539.32686-15-f4bug@amsat.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>