[meta-ti] BeagleBone Black - linux-ti-staging and kernel modesetting

[Denys Dmytriyenko]

Jonathan,

Here's the reply from our DRM guy:

> It should work, it looks to me like it is failing to probe for the tda998x 
> which is why the DRM driver is reporting no connectors/encoders.  They will 
> also need to make some changes to the DTS to get the thing to probe.  This 
> document has the necessary DT entries - refer to the DRM section - (it 
> wasn't there for the last 3.12 release so not an RTFM message).  
> http://processors.wiki.ti.com/index.php/Linux_Core_LCD_Controller_User_Guide#AM335x_LCDC_Display_Driver_.28fbdev.29
> 
> Darren
> 
> > Date: Thu, 30 Jan 2014 00:08:56 +1100
> > From: Jonathan Liu <net147 at gmail.com>
> > To: meta-ti at yoctoproject.org
> > Subject: [meta-ti] BeagleBone Black - linux-ti-staging and kernel modesetting
> > 
> > Hi,
> > 
> > I am using Yocto dora release with latest meta-ti git compiling for
> > BeagleBone Black using systemd.
> > For systemd to boot I had created linux-ti-staging_3.12.bbappend with
> > do_configure_append() that
> > appends the following options to kernel config:
> > CONFIG_CGROUPS=y
> > CONFIG_FHANDLE=y
> > 
> > More kernel options to enable additional support for systemd can be
> > found at: http://cgit.freedesktop.org/systemd/systemd/tree/README
> > 
> > I have also added the following for graphics support:
> > CONFIG_DRM=y
> > CONFIG_DRM_KMS_HELPER=y
> > CONFIG_DRM_GEM_CMA_HELPER=y
> > CONFIG_DRM_KMS_CMA_HELPER=y
> > CONFIG_DRM_I2C_NXP_TDA998X=y
> > CONFIG_DRM_TILCDC=y
> > 
> > The kernel mode switching (using xf86-video-modesetting) with HDMI
> > output however is not working.
> > 
> > The kernel log shows:
> > tilcdc 4830e000.lcdc: no encoders/connectors found
> > tilcdc 4830e000.lcdc: failed to initialize mode setting
> > 
> > The expected result (from Arch Linux ARM) is:
> > tilcdc 4830e000.fb: found TDA19988
> > tilcdc 4830e000.fb: fb0:  frame buffer device
> > tilcdc 4830e000.fb: registered panic notifier
> > [drm] Initialized tilcdc 1.0.0 20121205 on minor 0
> > 
> > /sys/class/drm/card0/card0-HDMI-A-1 doesn't exist also.
> > What am I missing to get KMS working with meta-ti linux-ti-staging for
> > the BeagleBone Black?
> > 
> > Regards,
> > Jonathan