Laurent Pinchart writes: > Hi Eric, > > On Tuesday 16 May 2017 11:46:36 Eric Anholt wrote: > > [snip] > >> In terms of physical connections: >> >> [15-pin "DSI" connector on 2835] >> >> | I2C | DSI >> / \ SPI | >> [TS] [Atmel]------[TC358762] >> \ | >> \PWM | >> \ | DPI >> [some backlight]------[some unknown panel] >> >> The binding I'm trying to create is to expose what's necessary for a >> driver that talks I2C to the Atmel, which then controls the PWM and does >> the command sequence over SPI to the Toshiba that sets up its end of the >> DSI link. > > According to the documentation I've been able to find, the TC358762 has an SPI > master port through which it can output the commands DCS received from the DSI > port, and an I2C slave port through which it can be configured by an external > device. If the connection between the microcontroller and the TC358762 is > indeed SPI and not I2C, I assume it's used by the microcontroller to receive > the DCS commands and perform control of the backlight (and possibly other > components) accordingly. By the way, is there any place where I can find a > leaked version of the non-public panel schematics ? ;-) Not that I know of. I don't know that you can control the backlight over DCS, given that I have no docs. We only send commands from Atmel to TC, not the other way around. > As far as I can tell from your patch series, you don't need to send any > command to the TC358762 over DSI. In that case I would model the panel in DT > as an I2C device, as all control goes through the I2C bus. The DSI video data > connection should then be modelled using the OF graph DT bindings. The result > will be a black box panel with a custom black box panel driver, using a single > DT node. There's no need for a separate bridge instance. That's the cleanest > option I can come up with so far, and I agree that splitting TC358762 support > into a standalone bridge driver makes no sense in this case. I agree, it's just that when I submitted to drm-panel I was told that it didn't make sense as a single driver, so I went to all of this work instead.