On Fri, Feb 28, 2014 at 06:15:05PM +0200, Tomi Valkeinen wrote:
On 28/02/14 18:06, Russell King - ARM Linux wrote:
+hdmi0: connector@1 {
- compatible = "hdmi-connector";
- label = "hdmi";
- hdmi_connector_in: endpoint {
remote-endpoint = <&tpd12s015_out>;- };
+};
It seems rather weird to have DVI connectors having an optional I2C property, but HDMI (which augments DVI) not having that as at least an optional property.
I have added only the properties that I have used. I did think about the i2c for HDMI also, but thought that I don't use it, and so can't test it, and so I could well create a bad binding.
And, as I don't see any issue in adding it later, when someone uses it, I decided to leave it out.
I can quite well see the iMX HDMI support needing an i2c bus here.
Also, HDMI has two connector standards - type A and type B, much like the single vs dual link of DVI. Again, DRM exposes this to userspace.
True, but isn't that just a form factor? No functional differences? But I agree, we can add the two types here also to the compatible string.
HDMI A is 19 pins carrying TMDS channels 0-2. HDMI B is 29 pins carrying TMDS channels 0-5. So, the difference is the same as the single vs dual link on DVI-D/I connectors.
There's actually three HDMI connectors:
All three connectors carry all required HDMI signals, including a TMDS link. The Type B connector is slightly larger and carries a second TMDS link, which is necessary to support very high resolution displays using dual link. The Type C connector carries the same signals as the Type A but is more compact and intended for mobile applications.
So, Type C and Type A are electrically the same.