> From: linux-tegra-owner at vger.kernel.org [mailto:linux-tegra- > owner at vger.kernel.org] On Behalf Of Thierry Reding > Sent: Thursday, July 05, 2012 8:15 PM > To: linux-tegra at vger.kernel.org > Cc: devicetree-discuss at lists.ozlabs.org; dri-devel at lists.freedesktop.org > Subject: Re: Tegra DRM device tree bindings > > * PGP Signed by an unknown key > > Here's a new proposal that should address all issues collected during the > discussion of the previous one: > > From tegra20.dtsi: > > host1x { > compatible = "nvidia,tegra20-host1x", "simple-bus"; > reg = <0x50000000 0x00024000>; > interrupts = <0 65 0x04 /* mpcore syncpt */ > 0 67 0x04>; /* mpcore general */ > > #address-cells = <1>; > #size-cells = <1>; > > ranges = <0x54000000 0x54000000 0x04000000>; > > /* video-encoding/decoding */ > mpe { > reg = <0x54040000 0x00040000>; > interrupts = <0 68 0x04>; > }; > > /* video input */ > vi { > reg = <0x54080000 0x00040000>; > interrupts = <0 69 0x04>; > }; > > /* EPP */ > epp { > reg = <0x540c0000 0x00040000>; > interrupts = <0 70 0x04>; > }; > > /* ISP */ > isp { > reg = <0x54100000 0x00040000>; > interrupts = <0 71 0x04>; > }; > > /* 2D engine */ > gr2d { > reg = <0x54140000 0x00040000>; > interrupts = <0 72 0x04>; > }; > > /* 3D engine */ > gr3d { > reg = <0x54180000 0x00040000>; > }; > > /* display controllers */ > dc at 54200000 { > compatible = "nvidia,tegra20-dc"; > reg = <0x54200000 0x00040000>; > interrupts = <0 73 0x04>; > > rgb { > status = "disabled"; > }; > }; > > dc at 54240000 { > compatible = "nvidia,tegra20-dc"; > reg = <0x54240000 0x00040000>; > interrupts = <0 74 0x04>; > > rgb { > status = "disabled"; > }; > }; > > /* outputs */ > hdmi { > compatible = "nvidia,tegra20-hdmi"; > reg = <0x54280000 0x00040000>; > interrupts = <0 75 0x04>; > status = "disabled"; > }; > > tvo { > compatible = "nvidia,tegra20-tvo"; > reg = <0x542c0000 0x00040000>; > interrupts = <0 76 0x04>; > status = "disabled"; > }; > > dsi { > compatible = "nvidia,tegra20-dsi"; > reg = <0x54300000 0x00040000>; > status = "disabled"; > }; > }; > > From tegra20-medcom.dts: > > host1x { > dc at 54200000 { > rgb { > nvidia,edid = /incbin/("tegra20-medcom.edid"); > status = "okay"; > }; > }; > }; > > From tegra20-plutux.dts: > > host1x { > hdmi { > vdd-supply = <&ldo7_reg>; > pll-supply = <&ldo8_reg>; > > nvidia,hpd-gpio = <&gpio 111 0>; /* PN7 */ > nvidia,ddc-i2c-bus = <&ddc>; > > status = "okay"; > }; > }; > > One problem I've come across when trying to get some rudimentary code > working with this is that there's no longer a device which the DRM driver can > bind > to, because the top-level device (host1x) now has a separate driver. > > I've briefly discussed this with Dave Airlie on IRC and there are basically > two > solutions: > > a) Use a fake platform device, instantiated from the device tree or at > module initialization time, so that the drm_platform_init() > function can be used.
If we change the dts to this version, that means we should register all drivers(dc/rgb/dsi...) during host1x driver initialization. In that case, I think we can register drm driver as well. It's not a good idea to add drm into dts cause just as you said, it's not a real device at all. > b) Implement a custom drm_bus and reimplement most of the > functionality provided by drm_platform_init(). > > Alternative a) is what Sascha has been doing for i.MX and is the most > straightforward. One variant of this would be to add another virtual device > node > below host1x that groups gr2d, gr3d, both dcs and the three output nodes. The > down-side of this being that it doesn't describe the hardware of course, and > therefore really shouldn't go into the device tree. Instantiating at module > initalization time has the disadvantage that the parent-child relationship is > lost. > > Using b) isn't optimal either because DRM requires at least a struct device > which > can be associated with the drm_device. So the question is which struct device > that should be? > > Thierry > > * Unknown Key > * 0x7F3EB3A1
