OpenCloudOS-Kernel/drivers/gpu/drm/bridge
Russell King dfbdaf5046 drm: bridge/dw_hdmi: replace CTS calculation for the ACR
Given the TDMS clock, audio sample rate, and the N parameter, we can
calculate the CTS value for the audio clock regenerator (ACR) using the
following calculation given in the HDMI specification:

	CTS = ftdms * N / (128 * fs)

The specification says that the CTS value is an average value, which is
true if the source hardware measures it.  Where source hardware needs it
to be programmed, it is particularly difficult to alternate between two
values correctly to ensure that we achieve a correct "average"
fractional value at the sink.

Also, there's the problem that our "ftdms" is not a fully accurate
value; it is rounded to a kHz value.  This introduces an unnecessary
(and harmless) fractional value into the above equation for combinations
like 148.5MHz/1.001 for 44100Hz - we still calculate the correct CTS
value.

Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-10-09 17:21:21 +01:00
..
Kconfig drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver 2015-10-09 17:17:24 +01:00
Makefile drm: bridge/dw_hdmi-ahb-audio: add audio driver 2015-10-09 17:14:12 +01:00
dw_hdmi-ahb-audio.c drm: bridge/dw_hdmi-ahb-audio: allow larger buffer sizes 2015-10-09 17:17:30 +01:00
dw_hdmi-audio.h drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver 2015-10-09 17:17:24 +01:00
dw_hdmi.c drm: bridge/dw_hdmi: replace CTS calculation for the ACR 2015-10-09 17:21:21 +01:00
dw_hdmi.h drm: bridge/dw_hdmi-ahb-audio: add audio driver 2015-10-09 17:14:12 +01:00
nxp-ptn3460.c drm/bridge: Add vendor prefixes 2015-08-14 21:34:24 +02:00
parade-ps8622.c drm/bridge: Add vendor prefixes 2015-08-14 21:34:24 +02:00