On Fri, Mar 05, 2021 at 11:46:35AM +0100, Pavel Machek wrote:

Hi!

quoted

quoted

quoted

For motorola modem case, we may have a GNSS device on channel 4.
Let's add that to the binding and example.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 .../devicetree/bindings/serdev/serdev-ngsm.yaml          | 9 +++++++++
 1 file changed, 9 insertions(+)

quoted

And since we're describing a mux, I think you need nodes for the virtual
ports rather than a reg property in what should be a serial client. That
is something like

	serial@nnn {
		modem {
			compatible = "etsi,ts27001-mux";

			serial@4 {
				compatible = "etsi,ts27001-serial";
				reg = <4>;

				gnss {
					compatible = "motorola,motmdm-gnss";
				};
			};
		};
	};

This way you can actually use serdev for the client drivers (e.g. for
gnss), and those drivers also be used for non-muxed ports if needed
(e.g. over USB).

I have done changes you requested, and then hit "serdev is busy
because it can have at most one child" limit in the code. You have
pretty clean driver in your inbox, and no reply. No help with serdev
core limitations, either. Can you start to communicate?

Heh, look at the devicetree example above that I gave you back in March.
It has the virtual serial ports described ("serial@4"), which you were
missing.

Johan