On Mon, Jan 12, 2015 at 06:13:41PM +0100, Jean-Francois Moine wrote: > On Mon, 12 Jan 2015 14:04:56 +0000 > Russell King - ARM Linux <linux at arm.linux.org.uk> wrote: > > On Mon, Jan 12, 2015 at 02:59:57PM +0100, Philipp Zabel wrote: > > > Note that of_graph_parse_endpoint interprets the port node's reg > > > property as port id. And the unit address part of the node name should > > > match the first address in the reg property. > > This is not the case in vexpress-v2p-ca15_a7.dts.
Hmm... as the DT binding doc doesn't specify this restriction, and we have a DT file which violates what Philipp has said, I think we ought to document that reg vs unit node name does not need to match each other, thereby making that official. > > So that's not going to work very well... because the AP register is a > > bitmask. > > > > I guess we could specify a node unit and reg, which the code otherwise > > ignores, and specify a philipps,ap-mask = property for the audio ports > > instead. > > Also, the video and audio ports must be distinguished. They could be > defined in different port groups. > > Example from the Cubox: > > video-ports: ports at 0 { > port { > tda998x_video: endpoint { > remote-endpoint = <&lcd0_0>; > nxp,video-port = <0x230145>; > }; > }; > }; > audio-ports: ports at 1 { > port at 0 { /* AP1 = I2S */ > tda998x_i2s: endpoint at 0 { > remote-endpoint = <&audio1_i2s>; > nxp,audio-port = <0x03>; > }; > }; > port at 1 { /* AP2 = S/PDIF */ > tda998x_spdif: endpoint at 1 { > remote-endpoint = <&audio1_spdif1>; > nxp,audio-port = <0x04>; > }; > }; > }; > > The port type is identified by the bit AP0. I don't particularly like that - that makes the assumption that AP0 always means I2S. What if a future chip decides to allow SPDIF on AP0? Why should we need to re-invent the binding? IMHO, it would be much better to make this explicit. Note that the "video-ports" and "audio-ports" are just labels in the DT file; they aren't carried through to the resulting DT binary file, so they don't have any meaning to the kernel. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.