On Tue, 13 Jan 2015 19:54:15 +0000 Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Tue, Jan 13, 2015 at 09:41:01PM +0200, Jyri Sarha wrote: > > On 01/13/2015 09:26 PM, Russell King - ARM Linux wrote: > > >SCLK: _~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_~_ > > > WS: __~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~________________________________~ > > >I2S1: llmm............................llmm............................llm > > >I2S2: llmm............................llmm............................llm > > >I2S3: llmm............................llmm............................llm > > >I2S4: llmm............................llmm............................llm > > > > > >So, what I'm saying is that it is_impossible_ to drive the TDA998x using > > >multiple I2S streams which are not produced by the same I2S block. > > > > This is besides the point, but it is possible that one of the multiple I2S > > blocks is the bit-clock and frame-clock master to the i2s bus and the others > > are slaves to it (banging their bits according to SCLK and WS of the I2S > > master). However, in this situation there really is only one i2s bus with > > multiple data pins. > > > > Just my 0.02€ to this discussion. > > Right, that's about the only way it could work. > > To represent that in DT, I would imagine we'd need something like this: > > #address-cells = <1>; > #size-cells = <0>; > ... > port@1 { /* AP1,2 = I2S */ > #address-cells = <1>; > #size-cells = <0>; > port-type = "i2s"; > reg = <0x01>; /* WS */ > tda998x_i2s1: endpoint@2 { > reg = <0x02>; /* AP1 */ > remote-endpoint = <&audio1_i2s>; > }; > tda998x_i2s2: endpoint@4 { > reg = <0x04>; /* AP2 */ > remote-endpoint = <&audio2_i2s>; > }; > }; > > where audio1_i2s is operating in master mode, and audio2_i2s is > operating in slave mode for both WS and SCLK. > > If we can agree on that, then I'm happy with the proposed binding. > (Remember that #address-cells and #size-cells are required in the > parent where we have reg= in the child.) #address-cells and #size-cells may be defined in any of the upper parent, so, as it is defined in the device, it is not needed in the port (see of_n_addr_cells in drivers/of/base.c). Well, I am a bit lost between (only one source / many channels - I2S busses) and (many sources / one I2s bus!). Anyway, I don't understand your example. I'd expect that a port would be a DAI. If yes, when playing is active, both endpoints receive an audio stream from the remote audio devices, and the AP register is always set to 0x07 (= 0x01 | 0x02 | 0x04). Then, it would have been simpler to have: #address-cells = <1>; #size-cells = <0>; ... port@7 { /* AP1,2 = I2S */ port-type = "i2s"; reg = <0x07>; /* WS + AP1 + AP2 */ tda998x_i2s1: endpoint@1 { remote-endpoint = <&audio1_i2s>; }; tda998x_i2s2: endpoint@2 { remote-endpoint = <&audio2_i2s>; }; }; If no, the two DAIs must be created from the endpoints, permitting streaming on i2s1 alone, i2s2 alone or both i2s1+i2s2 at the same time. Then, it would have been simpler to define the DAIs from the ports: #address-cells = <1>; #size-cells = <0>; ... port@3 { /* AP1 = I2S */ port-type = "i2s"; reg = <0x03>; /* WS + AP1 */ tda998x_i2s1: endpoint { remote-endpoint = <&audio1_i2s>; }; }; port@5 { /* AP2 = I2S */ port-type = "i2s"; reg = <0x05>; /* WS + AP2 */ tda998x_i2s1: endpoint { remote-endpoint = <&audio1_i2s>; }; }; -- Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel