Messages in this thread | | | From | Hans de Goede <> | Subject | Re: [RFC][PATCH 2/3] usb: roles: Add usb role switch notifier. | Date | Wed, 16 Oct 2019 11:10:32 +0200 |
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Hi,
On 10/15/19 7:39 AM, John Stultz wrote: > On Thu, Oct 3, 2019 at 1:51 PM Hans de Goede <hdegoede@redhat.com> wrote: >> On 03-10-2019 22:37, John Stultz wrote: >>> Fair point. I'm sort of taking a larger patchset and trying to break >>> it up into more easily reviewable chunks, but I guess here I mis-cut. >>> >>> The user is the hikey960 gpio hub driver here: >>> https://git.linaro.org/people/john.stultz/android-dev.git/commit/?id=b06158a2d3eb00c914f12c76c93695e92d9af00f >> >> Hmm, that seems to tie the TypeC data-role to the power-role, which >> is not going to work with role swapping. > > Thanks again for the feedback here. Sorry for the slow response. Been > reworking some of the easier changes but am starting to look at how to > address your feedback here. > >> What is controlling the usb-role-switch, and thus ultimately >> causing the notifier you are suggesting to get called ? > > The tcpm_mux_set() call via tcpm_state_machine_work() > >> Things like TYPEC_VBUS_POWER_OFF and TYPEC_VBUS_POWER_ON >> really beg to be modeled as a regulator and then the >> Type-C controller (using e.g. the drivers/usb/typec/tcpm/tcpm.c >> framework) can use that regulator to control things. >> in case of the tcpm.c framework it can then use that >> regulator to implement the set_vbus callback. > > So I'm looking at the bindings and I'm not sure exactly how to tie a > regulator style driver into the tcpm for this? > Looking at the driver I just see this commented out bit: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/typec/tcpm/tcpm.c#n3075 > > Do you happen to have a pointer to something closer to what you are describing?
Look at the tcpm_set_vbus implementation in drivers/usb/typec/tcpm/fusb302.c you need to do something similar in your Type-C controller driver and export the GPIO as as a gpio-controlled regulator and tie the regulator to the connector.
Regards,
Han
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