On Wed, Feb 15, 2017 at 03:34:55PM +0100, gianluca wrote: > On 02/15/2017 12:51 PM, Sascha Hauer wrote: > > On Tue, Feb 14, 2017 at 11:32:44AM +0100, gianluca wrote: > > > On 02/10/2017 08:35 AM, Sascha Hauer wrote: > > > > Hi Gianluca, > > > > > > > > On Thu, Feb 09, 2017 at 03:37:41PM +0100, gianluca wrote: > > > > > Hello, > > > > > I would like to know if there is a clear way on using the lvds pins to drive > > > > > a LVDS display in a custom made board, based on iMX6Q (in the near future > > > > > the iMX6Dual). > > > > > > > > I think what you are looking for is of_device_enable_and_register() or > > > > of_device_enable_and_register_by_name(). You can call it on either the > > > > lvds device node or the hdmi device node, depending on whether you found > > > > an EEPROM or not. > > > > > > > > > > I think this is not necessary as during boot I can see clearly: > > > > > > > imx-ipuv3 2400000.ipu: IPUv3H probed > > > > imx-ipuv3 2800000.ipu: IPUv3H probed > > > > imx-ldb ldb.10: probe failed: Invalid argument > > > > imx-hdmi 120000.hdmi: Detected HDMI controller 0x13:0xa:0xa0:0xc1 > > > > > > So barebox is trying to bring-up the imx-ldb but fails. > > > > > > So I suppose something is wrong in my device tree structure. > > > > Nope, there's everything right. > > > > I can reproduce this here on a GuF Santaro board. LVDS works fine on > > current barebox as long as I leave hdmi disabled in the device tree. > > When I enable hdmi I also get a "failed to get modes". > > > > Normally when different outputs are available then one would expect > > that each one of them is routed to some framebuffer, maybe with some > > sane default and configurable during runtime. The current code falls > > short here. > > What happens is each framebuffer looks around for outputs, all finding > > hdmi and lvds. Now the hdmi output may not have a monitor connected > > and returns no valid mode. In this case the lvds is not even asked for > > modes. > > Also in the current code it can happen that the lvds is asked for modes > > which are then applied to hdmi. > > Where we currently are is that it should work when exactly one output > > is enabled. Does lvds work properly when hdmi is disabled? In this > > case I would suggest that you manipulate your devicetree so that exactly > > one output is enabled. > > > > > That's works. Thank you! > > Now I am planning to adapt the (internal) and external device-tree to match > the hardware. > > First of all hdmi and ldb node are "disabled" by default. > > Then I am looking for any eeprom in the lvds connector I have. > If it is found, check the phandle "native-mode" of the display-timings node > to match the value found in eeprom. If not matches the native-mode, it > should change the native-mode phandle accordingly with the value found. (I > was thinking about of_find_node_by_name() and then change its value using > of_set_property_to_child_phandle(display, "native-mode")). And finally > change the status of ldb node from "disabled" to "okay". Is this the correct > way of doing this? > > If no eeprom is found activate the status of the hdmi node from "disabled" > to "okay". So with the same algorithm as above, > > Those operations will be done in the coredevice_initcall() level. Is this > correct? Sounds like a plan. I'm not sure though if you find your EEPROM at coredevice_initcall time. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
