[PATCH 0/5] Fixes to Tegra USB role switching and Smaug USB role switching enablement

Diogo Ivo
2025-12-04T21:37:05Z

Hello,

This patch series contains two fixes for USB role switching on the
Tegra210 SoC, as well as enabling this feature on the Pixel C.

The first patch addresses a wrong check on the logic that disables the
VBUS regulator.

The second patch guarantees proper ordering of events when switching PHY
roles.

The third and fourth patches then add the necessary nodes and properties
in the Smaug DT in order for role switching to work. Currently with this
patch series this feature can only be controlled from userspace by writing
the desired role to sysfs as

echo "role" > /sys/class/usb_role/usb2-0-role-switch/role

with role being one of {device, host, none}.

Further patches will enable automatic role switching via the 'cros_ec_typec'
driver which is currently broken on Smaug.

N.B: This series does not add a 'connector' node under the 'usb-role-switch'
property added on patch 04/04 because for Smaug the connector should instead
be under the node for 'cros_ec_typec' node and as stated above this
driver is currently broken for this device. If it is deemed better to
describe it but explicitly disable the node let me know and I will send
out a v2.

Signed-off-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
---
Diogo Ivo (5):
usb: host: tegra: Remove redundant pm_runtime_mark_last_busy() call
phy: tegra: xusb: Fix USB2 port regulator disable logic
phy: tegra: xusb: Fix ordering issue when switching roles on USB2 ports
arm64: tegra: smaug: Complete and enable tegra-udc node
arm64: tegra: smaug: Add usb-role-switch support

arch/arm64/boot/dts/nvidia/tegra210-smaug.dts | 13 +++++++++++++
drivers/phy/tegra/xusb-tegra210.c | 5 +++--
drivers/phy/tegra/xusb.c | 23 +++++++++++++++++++++++
drivers/phy/tegra/xusb.h | 1 +
drivers/usb/gadget/udc/tegra-xudc.c | 4 ++++
drivers/usb/host/xhci-tegra.c | 17 ++++++++++-------
include/linux/phy/tegra/xusb.h | 1 +
7 files changed, 55 insertions(+), 9 deletions(-)
---
base-commit: a8817ff3b5cd99b0a5af57a92d1a3a7980612550
change-id: 20251201-diogo-tegra_phy-86c89cab7377

Best regards,
--
Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>