Quoting Peter Rosin (2017-07-11 22:04:46) > On 2017-07-12 03:02, Stephen Boyd wrote: > > This patchset adds support for the TC7USB40MU usb mux found on > > db410c 96boards platforms via the new multiplexer framework and > > hooks that into the chipidea driver. This allows us to properly > > control host or device mode on this board via the sysfs knob. > > > > So far I've only tested this on db410c, and there are some rough > > edges to finish off before it can merge. Also I'm experiencing > > odd behavior with switching the role while gadget is enabled and > > the micro-usb cable is kept connected. Not sure what's wrong but > > it seems like the gadget never gets disconnected? I'll investigate > > more. > > > > TODO: > > > > 1. The mux framework has to be selected for consumers to use it. We'll > > need some stubs in the consumer header file to allow compilation to > > continue without mux always enabled by consumers. > > Instead of "depends on MULTIPLEXER", just add "select MULTIPLEXER" > to the Kconfig. Otherwise, you'll have to convince Linus that we > really do need a Kconfig question for the subsystem :-) > > https://lkml.org/lkml/2017/7/4/118 Ok. I'll add a select to the chipidea driver. > > > 2. We probably need some sort of mux_control_get_optional() API so that > > we know if there was an error getting the mux control, instead of just > > ignoring errors. For now I can pass up EPROBE_DEFER errors and ignore > > other errors and consider it "missing from DT". > > Yes, mux_control_get_optional should be easy to add. > > > 3. Maybe we can get rid of the mux driver and just use mux-gpio.c with > > a compatible string update? I split it off because we may want to > > support the "S" pin on the TC7USB40MU one day that shuts off both Oh this is a typo. I mean "OE" pin. > > mux outputs. > > Maybe no need for a compatible update either, if it works to do something > like this in the DT? > > usb_switch: usb-switch { > compatible = "gpio-mux"; > mux-gpios = <&pm8916_gpios 4 GPIO_ACTIVE_HIGH>, > <&pm8916_gpios XXX GPIO_ACTIVE_XXX>; > idle-state = <2>; > #mux-control-cells = <0>; > pinctrl-names = "default"; > pinctrl-0 = <&usb_sw_sel_pm>; > }; > > But I obviously know little about how things are wired and really works, > so that might be totally off... > > Otherwise, maybe a generic mux-pinctrl driver would do the trick? > (compare with drivers/i2c/muxes/i2c-mux-pinctrl.c) > Agreed. On the board I have the "OE" pin is shorted so that it always outputs a signal. For someone else they could do what you say and add another pin to gpio-mux binding and things will still work. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
