On Mon, Nov 24, 2014 at 11:46:18AM +0200, Laurent Pinchart wrote:
- the interface looks rather backwards: Either this still does i2c reads, and then you'd just need a i2c-over-whatever adapter to make it work. Or you have other magic means to optain an edid block, in which case just do that and then feed the edid drm_add_edid_modes.
I have a magic way to get EDID over I2C :-) Basically the ADV7511 controls the DDC bus, and exposes EDID data over I2C using vendor commands. To read an EDID block I have to write an ADV7511 register over I2C with the block number, wait for an interrupt, read a status register to check whether EDID data is available or whether an error occurred, and then read EDID data from the ADV7511 over I2C in 64-bytes chunks. This needs to be repeated for every block. I thus can't use drm_get_edid() directly.
Sounds familiar. See the special ddc-over-sdvo i2c bus we register in intel_sdvo.c, specifically look at intel_sdvo_init_ddc_proxy. It is a bit of boilerplate, but in the end just amounts to 3 small functions and one tiny vtable to wire it all up cleanly. -Daniel