Hi Tobias, Sorry for a late reply. Please refer to the comments below. On 04/27/2014 02:33 AM, Tobias Jakobi wrote: > Hello, > > I'm trying to get the HDMI port working on a Exynos4412 based board. > Attached is a snippet of a dts. This config was supposed to "work" in > the past. > > However with 3.15-rc1 some things changed. samsung,exynos4210-hdmiddc > and samsung,exynos4212-hdmiphy have no function anymore, the code that > previously handled these compatible strings is gone. > > So, it looks like that without some patching, HDMI support is atm broken. > > I have applied these: > http://www.spinics.net/lists/linux-samsung-soc/msg28161.html > http://www.spinics.net/lists/linux-samsung-soc/msg28259.html > > With the first one I can drop a clock from the hdmi node. But then > trouble starts. > > So, first of all I'm unsure what the 'hdmiddc' node should be converted > to. Documentation (exynos_hdmi.txt) doesn't help here, since it just > says "phandle to the hdmi ddc node". What kind of 'hdmi ddc node'? From > the code it looks like that it should point to an i2c adapter now. So > should it point to 'i2c_2' now? The spec is wrong. It should be a handle to I2C adapter. The semantics of this node was changed in patch "drm/exynos: hdmi: use i2c_adapter instead of i2c_client" 8fa04aae2aa8bafcfc027856904ebee0060506d0 > > The second thing is 'phy', which should be a "phandle to the hdmi ddc > node". Again, no idea what that node should be. Apparantly such nodes > can't be created with current kernel code anyway, primary reason to > apply the simply-phy patches. The meaning of hdmiphy is ambiguous. In exynos4 spec there are _TWO_ components named HDMIPHY. The first one is a PLL that generates a clock for HDMI subsystem. This PLL is controlled by I2C. You can find an example of its bindings at: http://lists.freedesktop.org/archives/dri-devel/2013-October/047687.html The second one is HDMI's physical interface located in PMU unit. The exynos-simple-phy is dedicated to controller the former (component of PMU). The 'phy' attribute in DT refers to the PLL. There is a debate if 'phy' should refer to I2C device itself or rather to I2C bus. Currently it refers to driverless instance of I2C device. > > OK, so I have to put a simple-phys node in my dts now. Or, wait, do I > just replace the hdmiphy node with a simple-phys node? > > Would look something like this: > hdmiphy: simple-phys@38 { > compatible = "samsung,exynos4412-simple-phy"; > reg = <0x38 0x10000>; > #phy-cells = <1>; > }; > > Somehow this doesn't look right. And indeed: > https://patchwork.kernel.org/patch/4021121/ > > At least for exynos5250 this node is not a child on an i2c adapter. This is a completely different HDMIPHY. > > And yes, I would still have to add 'phys' and 'phy-names' to the hdmi > node. This looks wrong again. Why do I have to specify 'phys' when I > already have 'phy' there? Isn't that redundant? 'phys' and 'phy-names' refers to PHY interfaces delivered by phy-core. The attribute named 'phy' refers to I2C device used to controller HDMI's PLL. The naming convention is very misleading. > > Well, you see, lots of confusion here. I would appreciate any kind of > help on how to proceed here. The documentation for HDMI's bindings should be fixed. > > With best wishes, > Tobias > Regards, Tomasz Stanislawski -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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