Hi!
I naively thought that since there was support for both nxp,tda19988 (in the tda998x driver) and the atmel-hlcdc, things would be a smooth ride. But it wasn't, so I started looking around and realized I had to fix things.
In v1 and v2 I fixed things by making the atmel-hlcdc driver a master component, but now I fix things by making the tda998x driver a bridge instead. This was after a suggestion from Boris Brezillon the atmel-hlcdc maintainer), so there was some risk of bias ... but after comparing what was needed, I too find the bridge approach more direct. In v4, an issue was noted by Russell King in that the tda998x device might be unbound with shattering results for the main drm device. This is of course a real problem and it needs to be fixed. I have submitted a series [1] that tries to do that. However, since there are currently *10* other bridges (analogix-anx78xx, adv7511, megachips_stdp*, nxp-ptn3460, parade-ps8622, sii902x, sii9234, sil-sii8620, tc358767 and ti-tfp410) with exactly the same problem (they are all I2C devices that might be unexpectedly unbound without safety-net, at least that is how I read it), I think it should be ok to add one more and then fix them all instead of holding this series hostage. Apparently people don't go around and unbind I2C devices all that often...
In addition to the above, our PCB interface between the SAMA5D3 and the HDMI encoder is only using 16 bits, and this has to be described somewhere, or the atmel-hlcdc driver have no chance of selecting the correct output mode. Since I have similar problems with a ds90c185 lvds encoder I added patches to override the atmel-hlcdc output format via DT properties compatible with the media video-interface binding and things start to play together.
Anyway, this series solves some real issues for my HW.
Also, is it perhaps possible that patches 1-3 can be taken independently from 4-7? There is no hard dependency between the two parts of this series. Patches 1-3 have the relevant tags and should be uncontroversial...
Cheers, Peter
Changes since v4 https://lkml.org/lkml/2018/4/23/92 - added reviewed-by from Rob to patch 2/7 - dropped patch 8, since the issue noted by Russell King is not present when working with components as tilcdc currently do when handling tda998x
Changes since v3 https://lkml.org/lkml/2018/4/19/736 - moved the meat of the drm_of_media_bus_fmt function from patch 3/7 to a driver-local atmel_hlcdc_of_bus_fmt function, and squashed with patch 4/7 (this is now patch 3/8). - patch 3/8 now parses and stores the DT bus format together with the encoder in a reintroduced struct atmel_hlcdc_rgb_output instead of allocating a separate encoder-indexed array for the bus formats. - patch 5/8 is new and splits tda988x_encoder_dpms into a pair of functions to enable/disable separately. This fits better with both the current code and for the followup drm_bridge patch (7/8). - adjust patch 6/8 and 7/8 to the above simplification. - added patch 8/8 that removes component master code from tilcdc.
Changes since v2 https://lkml.org/lkml/2018/4/17/385 - patch 2/7 fixed spelling and added an example - patch 4/7 parse the DT up front and store the result indexed by encoder - old patch 5/6 and 6/6 dropped - patch 5-7/7 are new and makes the tda998x driver a drm_bridge
Changes since v1 https://lkml.org/lkml/2018/4/9/294 - added reviewed-by from Rob to patch 1/6 - patch 2/6 changed so that the bus format override is in the endpoint DT node, and follows the binding of media video-interfaces. - patch 3/6 is new, it adds drm_of_media_bus_fmt which parses above media video-interface binding (partially). - patch 4/6 now makes use of the above helper (and also fixes problems with the 3/5 patch from v1 when no override was specified). - do not mention unrelated connector display_info details in the cover letter and commit messages.
[1] https://lkml.org/lkml/2018/5/16/380
Peter Rosin (7): dt-bindings: display: bridge: lvds-transmitter: add ti,ds90c185 dt-bindings: display: atmel: optional video-interface of endpoints drm/atmel-hlcdc: support bus-width (12/16/18/24) in endpoint nodes drm/i2c: tda998x: find the drm_device via the drm_connector drm/i2c: tda998x: split tda998x_encoder_dpms into enable/disable drm/i2c: tda998x: split encoder and component functions from the work drm/i2c: tda998x: register as a drm bridge
.../devicetree/bindings/display/atmel/hlcdc-dc.txt | 26 ++ .../bindings/display/bridge/lvds-transmitter.txt | 8 +- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 70 ++++-- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h | 1 + drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c | 67 +++++- drivers/gpu/drm/i2c/tda998x_drv.c | 268 ++++++++++++++++----- 6 files changed, 351 insertions(+), 89 deletions(-)