[PATCH 0/3] USB Mux support for Chipidea

From: Stephen Boyd
Date: Tue Jul 11 2017 - 21:03:21 EST

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


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.

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".

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
mux outputs.

4. The userspace side of things is murky. What is expected to go and toggle
the host/gadget side of things in userspace at this very specific location
for chipidea devices?

Stephen Boyd (3):
usb: misc: Add a driver for TC7USB40MU
usb: chipidea: Hook into mux framework to toggle usb switch
arm64: dts: qcom: Collapse usb support into one node

.../devicetree/bindings/usb/ci-hdrc-usb2.txt | 8 +++
.../devicetree/bindings/usb/toshiba,tc7usb40mu.txt | 31 +++++++++
arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi | 39 +++++++-----
arch/arm64/boot/dts/qcom/msm8916.dtsi | 62 +++++++++---------
drivers/usb/chipidea/core.c | 17 +++++
drivers/usb/chipidea/host.c | 10 +++
drivers/usb/chipidea/udc.c | 11 ++++
drivers/usb/misc/Kconfig | 11 ++++
drivers/usb/misc/Makefile | 1 +
drivers/usb/misc/tc7usb40mu.c | 74 ++++++++++++++++++++++
include/linux/usb/chipidea.h | 14 ++++
11 files changed, 228 insertions(+), 50 deletions(-)
create mode 100644 Documentation/devicetree/bindings/usb/toshiba,tc7usb40mu.txt
create mode 100644 drivers/usb/misc/tc7usb40mu.c