ASoC/tda998x: Fix reporting of nonexistent capture streams

Merge series from Mark Brown <broonie@kernel.org>:

The recently added pcm-test selftest has pointed out that systems with
the tda998x driver end up advertising that they support capture when in
reality as far as I can see the tda998x devices are transmit only.  The
DAIs registered through hdmi-codec are bidirectional, meaning that for
I2S systems when combined with a typical bidrectional CPU DAI the
overall capability of the PCM is bidirectional.  In most cases the I2S
links will clock OK but no useful audio will be returned which isn't so
bad but we should still not advertise the useless capability, and some
systems may notice problems for example due to pinmux management.

This is happening due to the hdmi-codec helpers not providing any
mechanism for indicating unidirectional audio so add one and use it in
the tda998x driver.  It is likely other hdmi-codec users are also
affected but I don't have those systems to hand.

Mark Brown (2):
  ASoC: hdmi-codec: Allow playback and capture to be disabled
  drm: tda99x: Don't advertise non-existent capture support

 drivers/gpu/drm/i2c/tda998x_drv.c |  2 ++
 include/sound/hdmi-codec.h        |  4 ++++
 sound/soc/codecs/hdmi-codec.c     | 30 +++++++++++++++++++++++++-----
 3 files changed, 31 insertions(+), 5 deletions(-)

base-commit: f0c4d9fc
--
2.30.2