iMX6 devices suffer from an errata (ERR005174) where the audio FIFO can
be emptied while it is partially full, resulting in misalignment of the
audio samples.
To prevent this, the errata workaround recommends writing N as zero
until the audio FIFO has been loaded by DMA. Writing N=0 prevents the
HDMI bridge from reading from the audio FIFO, effectively disabling
audio.
This means we need to provide the audio driver with a pair of functions
to enable/disable audio. These are dw_hdmi_audio_enable() and
dw_hdmi_audio_disable().
A spinlock is introduced to ensure that setting the CTS/N values can't
race, ensuring that the audio driver calling the enable/disable
functions (which are called in an atomic context) can't race with a
modeset.
Tested-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Introduce dw_hdmi_set_sample_rate(), which allows us to configure the
audio sample rate, setting the CTS/N values appropriately.
Tested-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Because of iMX6 & Rockchip have differnet mpll config parameter,
the VLEVCTRL parameter would be different. In this case we should
separate VLEVCTRL setting from the common dw_hdmi driver, config
this parameter in platform driver(dw_hdmi-imx and dw_hdmi-rockchip)
Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rockchip RK3288 hdmi is compatible with dw_hdmi
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
the original imx hdmi driver is under drm/imx/,
which depends on imx-drm, so move the imx hdmi
driver out to drm/bridge and rename it to dw_hdmi
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Russell King