linux/Documentation/devicetree/bindings/phy/phy-cadence-sierra.txt
Alan Douglas cb96a69072 dt-bindings: phy: Document cadence Sierra PHY bindings
Add DT binding documentation for Sierra PHY.  The PHY supports
a number of different protocols, including PCIe and USB.

The PHY lanes may be configured as single or multi-lane links.
Each link is treated as a separate sub-node.  For example, if
there are 4 lanes in total the first 2 might be configured as
a multi-lane PCIe link while the other two are single lane
USB links, and in this case there would be 3 sub-nodes.

There are two resets for the PHY block (one for APB register
access, one for the PHY link) and separate resets for each
link.  For multi-lane links, the reset corresponds to the
reset line on the master lane, the resets on other lanes
have no effect.

Signed-off-by: Alan Douglas <adouglas@cadence.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2018-12-12 10:01:38 +05:30

68 lines
2.2 KiB
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Cadence Sierra PHY
-----------------------
Required properties:
- compatible: cdns,sierra-phy-t0
- clocks: Must contain an entry in clock-names.
See ../clocks/clock-bindings.txt for details.
- clock-names: Must be "phy_clk"
- resets: Must contain an entry for each in reset-names.
See ../reset/reset.txt for details.
- reset-names: Must include "sierra_reset" and "sierra_apb".
"sierra_reset" must control the reset line to the PHY.
"sierra_apb" must control the reset line to the APB PHY
interface.
- reg: register range for the PHY.
- #address-cells: Must be 1
- #size-cells: Must be 0
Optional properties:
- cdns,autoconf: A boolean property whose presence indicates that the
PHY registers will be configured by hardware. If not
present, all sub-node optional properties must be
provided.
Sub-nodes:
Each group of PHY lanes with a single master lane should be represented as
a sub-node. Note that the actual configuration of each lane is determined by
hardware strapping, and must match the configuration specified here.
Sub-node required properties:
- #phy-cells: Generic PHY binding; must be 0.
- reg: The master lane number. This is the lowest numbered lane
in the lane group.
- resets: Must contain one entry which controls the reset line for the
master lane of the sub-node.
See ../reset/reset.txt for details.
Sub-node optional properties:
- cdns,num-lanes: Number of lanes in this group. From 1 to 4. The
group is made up of consecutive lanes.
- cdns,phy-type: Can be PHY_TYPE_PCIE or PHY_TYPE_USB3, depending on
configuration of lanes.
Example:
pcie_phy4: pcie-phy@fd240000 {
compatible = "cdns,sierra-phy-t0";
reg = <0x0 0xfd240000 0x0 0x40000>;
resets = <&phyrst 0>, <&phyrst 1>;
reset-names = "sierra_reset", "sierra_apb";
clocks = <&phyclock>;
clock-names = "phy_clk";
#address-cells = <1>;
#size-cells = <0>;
pcie0_phy0: pcie-phy@0 {
reg = <0>;
resets = <&phyrst 2>;
cdns,num-lanes = <2>;
#phy-cells = <0>;
cdns,phy-type = <PHY_TYPE_PCIE>;
};
pcie0_phy1: pcie-phy@2 {
reg = <2>;
resets = <&phyrst 4>;
cdns,num-lanes = <1>;
#phy-cells = <0>;
cdns,phy-type = <PHY_TYPE_PCIE>;
};