dt-bindings: phy: Add NVIDIA Tegra XUSB pad controller binding

The NVIDIA Tegra XUSB pad controller provides a set of pads, each with a
set of lanes that are used for PCIe, SATA and USB.

A binding exists for the XUSB pad controller already, but it turned out
not to be flexible enough to describe all aspects of the controller. In
particular, the addition of XUSB support (for SuperSpeed USB) has shown
that the existing binding is no longer suitable. Mark the old binding
as deprecated and link to the new binding.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt
index 30676ded85bb..8a6223dbc143 100644
--- a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt
@@ -1,6 +1,12 @@
 Device tree binding for NVIDIA Tegra XUSB pad controller
 ========================================================
 
+NOTE: It turns out that this binding isn't an accurate description of the XUSB
+pad controller. While the description is good enough for the functional subset
+required for PCIe and SATA, it lacks the flexibility to represent the features
+needed for USB. For the new binding, see ../phy/nvidia,tegra-xusb-padctl.txt.
+The binding described in this file is deprecated and should not be used.
+
 The Tegra XUSB pad controller manages a set of lanes, each of which can be
 assigned to one out of a set of different pads. Some of these pads have an
 associated PHY that must be powered up before the pad can be used.