linux.git/drivers/phy/tegra/xusb.c, branch v5.9

phy: tegra: Don't use device-managed API to allocate ports

2020-03-19T13:00:05+00:00

The device-managed allocation API doesn't work well with the life-cycle
of device objects. Since ports have device objects allocated within, it
can lead to situations where these devices need to stay around until
after their parent pad controller has been unbound from its driver. The
device-managed memory allocated for the port objects will, however, get
freed when the pad controller unbinds from the driver. This can cause
use-after-free errors down the road.

Note that the device is deleted as part of the driver unbind operation,
so there isn't much that can be done with it after that point, but the
memory still needs to stay around to ensure none of the references are
invalidated.

One situation where this arises is when a VBUS supply is associated with
a USB 2 or 3 port. When that supply is released using regulator_put() an
SRCU call will queue the release of the device link connecting the port
and the regulator after a grace period. This means that the regulator is
going to keep on to the last reference of the port device even after the
pad controller driver was unbound (which is when the memory backing the
port device is freed).

Fix this by allocating port objects using non-device-managed memory. Add
release callbacks for these objects so that their memory gets freed when
the last reference goes away. This decouples the port devices' lifetime
from the "active" lifetime of the pad controller (i.e. the time during
which the pad controller driver owns the device).

Signed-off-by: Thierry Reding

phy: tegra: Fix regulator leak

2020-03-19T13:00:04+00:00

Devices are created for each port of the XUSB pad controller. Each USB 2
and USB 3 port can potentially have an associated VBUS power supply that
needs to be removed when the device is removed.

Since port devices never bind to a driver, the driver core will not get
to perform the cleanup of device-managed resources that usually happens
on driver unbind.

Now, the driver core will also perform device-managed resource cleanup
for driver-less devices when they are released. However, when a device
link is created between the regulator and the port device, as part of
regulator_get(), the regulator takes a reference to the port device and
prevents it from being released unless regulator_put() is called, which
will never happen.

Avoid this by using the non-device-managed API and manually releasing
the regulator reference when the port is unregistered.

Signed-off-by: Thierry Reding

phy: tegra: Print -EPROBE_DEFER error message at debug level

2020-03-19T13:00:03+00:00

Probe deferral is an expected error condition that will usually be
recovered from. Print such error messages at debug level to make them
available for diagnostic purposes when building with debugging enabled
and hide them otherwise to not spam the kernel log with them.

Signed-off-by: Thierry Reding

phy: tegra: xusb: Add Tegra194 support

2020-03-19T12:59:46+00:00

Add support for the XUSB pad controller found on Tegra194 SoCs. It is
mostly similar to the same IP found on Tegra186, but the number of
pads exposed differs, as do the programming sequences. Because most of
the Tegra194 XUSB PADCTL registers definition and programming sequence
are the same as Tegra186, Tegra194 XUSB PADCTL can share the same
driver, xusb-tegra186.c, with Tegra186 XUSB PADCTL.

Tegra194 XUSB PADCTL supports up to USB 3.1 Gen 2 speed, however, it
is possible for some platforms have long signal trace that could not
provide sufficient electrical environment for Gen 2 speed. This patch
adds a "maximum-speed" property to usb3 ports which can be used to
specify the maximum supported speed for any particular USB 3.1 port.
For a port that is not capable of SuperSpeedPlus, "maximum-speed"
property should carry "super-speed".

Signed-off-by: JC Kuo 
Acked-by: Thierry Reding 
Signed-off-by: Thierry Reding

phy: tegra: xusb: Add support to get companion USB 3 port

2020-03-19T12:59:46+00:00

Tegra XUSB host, device mode driver requires the USB 3 companion port
number for corresponding USB 2 port. Add API to retrieve the same.

Signed-off-by: Nagarjuna Kristam 
Reviewed-by: JC Kuo 
Acked-by: Kishon Vijay Abraham I 
Signed-off-by: Thierry Reding

phy: tegra: xusb: Add usb-phy support

2020-03-19T12:59:45+00:00

For USB 2 ports that has usb-role-switch enabled, add usb-phy for
corresponding USB 2 phy. USB role changes from role switch are then
updated to corresponding host and device mode drivers via usb-phy notifier
block.

Signed-off-by: Nagarjuna Kristam 
Acked-by: Kishon Vijay Abraham I 
[treding@nvidia.com: rebase onto Greg's usb-next branch]
Signed-off-by: Thierry Reding

phy: tegra: xusb: Add usb-role-switch support

2020-03-19T12:54:35+00:00

If usb-role-switch property is present in USB 2 port, register
usb-role-switch to receive usb role changes.

Signed-off-by: Nagarjuna Kristam 
Acked-by: Kishon Vijay Abraham I 
[treding@nvidia.com: rebase onto Greg's usb-next branch]
Signed-off-by: Thierry Reding

phy: tegra: use regulator_bulk_set_supply_names()

2019-10-25T12:28:13+00:00

Use the new regulator helper instead of a for loop.

Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Kishon Vijay Abraham I

phy: tegra: xusb: Add vbus override support on Tegra210

2019-10-23T07:50:36+00:00

Tegra XUSB device control driver needs to control vbus override
during its operations, add API for the support.

Signed-off-by: Nagarjuna Kristam 
Acked-by: Thierry Reding 
Signed-off-by: Kishon Vijay Abraham I

phy: tegra: xusb: Add usb3 port fake support on Tegra210

2019-10-23T07:50:34+00:00

On Tegra210, usb2 only otg/peripheral ports dont work in device mode.
They need an assosciated usb3 port to work in device mode. Identify
an unused usb3 port and assign it as a fake USB3 port to USB2 only
port whose mode is otg/peripheral.

Based on work by BH Hsieh .

Signed-off-by: Nagarjuna Kristam 
Acked-by: Thierry Reding 
Signed-off-by: Kishon Vijay Abraham I