diff options
| author | Eric Anholt <eric@anholt.net> | 2017-02-27 12:11:43 -0800 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2017-02-28 12:51:49 -0800 |
| commit | f6c01530fd987eb70e051580d831ac04ef920352 (patch) | |
| tree | 3c294fd04e8f43cca7f728c7a2c96a001ea3a976 /drivers/gpu/drm/vc4/vc4_hdmi.c | |
| parent | 60c5d3b72989ec9922f9aa2bb5edc331659389dd (diff) | |
| download | linux-f6c01530fd987eb70e051580d831ac04ef920352.tar.bz2 | |
drm/vc4: Extend and edit documentation for output from the RST
I had written most of my comments as if I was describing the
individual code files the way I used to for doxygen, while for RST we
want to describe things in a more chapter/section way where there's no
obvious relation to .c files.
Additionally, several of the files had stub descriptions that I've
taken this opportunity to extend.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170227201144.10970-4-eric@anholt.net
Diffstat (limited to 'drivers/gpu/drm/vc4/vc4_hdmi.c')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hdmi.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 93d5994f3a04..1be1e8304720 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -20,9 +20,26 @@ /** * DOC: VC4 Falcon HDMI module * - * The HDMI core has a state machine and a PHY. Most of the unit - * operates off of the HSM clock from CPRMAN. It also internally uses - * the PLLH_PIX clock for the PHY. + * The HDMI core has a state machine and a PHY. On BCM2835, most of + * the unit operates off of the HSM clock from CPRMAN. It also + * internally uses the PLLH_PIX clock for the PHY. + * + * HDMI infoframes are kept within a small packet ram, where each + * packet can be individually enabled for including in a frame. + * + * HDMI audio is implemented entirely within the HDMI IP block. A + * register in the HDMI encoder takes SPDIF frames from the DMA engine + * and transfers them over an internal MAI (multi-channel audio + * interconnect) bus to the encoder side for insertion into the video + * blank regions. + * + * The driver's HDMI encoder does not yet support power management. + * The HDMI encoder's power domain and the HSM/pixel clocks are kept + * continuously running, and only the HDMI logic and packet ram are + * powered off/on at disable/enable time. + * + * The driver does not yet support CEC control, though the HDMI + * encoder block has CEC support. */ #include "drm_atomic_helper.h" |