* Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> [221011 13:57]: > Hi Sebastian, > > On Tue, Oct 11, 2022 at 02:37:26PM +0200, Sebastian Reichel wrote: > > Hi, > > > > On Tue, Oct 11, 2022 at 08:45:54AM +0300, Tony Lindgren wrote: > > > * Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> [221004 21:26]: > > > > The LCD driver (panel-sony-acx565akm), when probing, starts with line > > > > driven low, and then toggles it to high and keeps it there. Also, the > > > > line is driven low when powering off the device, and ls released when > > > > powering it back on. This means that the reset line should be described > > > > as "active low" in DTS. This will be important when the driver is > > > > converted to gpiod API which respects the polarity declared in DTS. > > > > > > We should ensure these patches get merged together with the driver > > > change to avoid breaking LCD for booting. Probably no need to have > > > the driver quirk handling for inverted polartity in this case. > > > > > > It's probably easiest to have an immutable branch for the driver > > > changes I can base the dts changes on. Or I can ack the dts changes > > > if they get merged with the driver. > > > > Both drivers are already using gpiod API: > > > > drivers/gpu/drm/panel/panel-sony-acx565akm.c > > drivers/gpu/drm/panel/panel-dsi-cm.c > > I was looking at > > drivers/video/fbdev/omap2/omapfb/displays/panel-sony-acx565akm.c > drivers/video/fbdev/omap2/omapfb/displays/panel-dsi-cm.c Ah OK that explains :) > which are not using gpiod. Should they be retired? Yes we should just get rid of them with omapdrm working just fine. > > So this just breaks things. > > I missed the drivers in drivers/gpu/... and I see that they essentially > abuse gpiod API as gpiod_set_value() operates on logical level > (active/inactive) and not absolute (high/low). They should either use > the gpiod_*_raw() variants, or they should be adjusted to do the proper > thing together with the accompanying DTS change. > > What are your preferences? Seems like high/low at the connected device end is what we should use, right? Otherwise things will misbehave if the panel is connected to some other SoC possibly. Regards, Tony
