On Fri, 09 Sep 2022, Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> wrote: > On Fri, Sep 09, 2022 at 11:35:28AM +0200, Aurélien wrote: >> Hi, >> I hope this mailing-mist is the right place for this question. > > + dri-devel mailing list that looks more appropriated. > + Hans and Lyude who were recently working to standardize some of the > backlight stuff. > >> I would like to develop a new driver in order to manage backlight for a >> specific OLED display (Samsung one). For that propose I need to use the >> dpcd aux read and write functions. >> Since this driver is independent film the i915 driver I would like to >> develop an indémependant driver. >> So my question is: how can I use the i915 API (dpcd aux communications) >> outside from the driver and register the backlight sys entries like the >> i915 does (in order to have all the softwares which plays with the >> backlight working without modifying them) ? > > I don't believe you want to use the i915 API, but move the common functions > to the drm subsystem itself and then reuse as a drm device. Aurélien, are you aware of drivers/gpu/drm/display/drm_dp_helper.c and all the functions around struct dp_aux_backlight and struct drm_edp_backlight_info? Also see drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c. Does the display use some proprietary, non-VESA DPCD registers? There's already some of that in i915 for Intel proprietary interfaces. BR, Jani. > >> Many thanks for your answers >> -- >> Aurélien -- Jani Nikula, Intel Open Source Graphics Center
