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Subject[PATCH v2 net-next 22/22] dt-bindings: net: dsa: Add documentation for NXP SJA1105 driver
Date
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v2:
Renamed sja1105,phy-mode to sja1105,role-phy and similarly for mac.
Clarified the switch situation with RGMII delays.

.../devicetree/bindings/net/dsa/sja1105.txt | 157 ++++++++++++++++++
1 file changed, 157 insertions(+)
create mode 100644 Documentation/devicetree/bindings/net/dsa/sja1105.txt

diff --git a/Documentation/devicetree/bindings/net/dsa/sja1105.txt b/Documentation/devicetree/bindings/net/dsa/sja1105.txt
new file mode 100644
index 000000000000..529401cf01ea
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/dsa/sja1105.txt
@@ -0,0 +1,157 @@
+NXP SJA1105 switch driver
+=========================
+
+Required properties:
+
+- compatible:
+ Must be one of:
+ - "nxp,sja1105e"
+ - "nxp,sja1105t"
+ - "nxp,sja1105p"
+ - "nxp,sja1105q"
+ - "nxp,sja1105r"
+ - "nxp,sja1105s"
+
+ Although the device ID could be detected at runtime, explicit bindings
+ are required in order to be able to statically check their validity.
+ For example, SGMII can only be specified on port 4 of R and S devices,
+ and the non-SGMII devices, while pin-compatible, are not equal in terms
+ of support for RGMII internal delays (supported on P/Q/R/S, but not on
+ E/T).
+
+Optional properties:
+
+- sja1105,role-mac:
+- sja1105,role-phy:
+ Boolean properties that can be assigned under each port node. By
+ default (unless otherwise specified) a port is configured as MAC if it
+ is driving a PHY (phy-handle is present) or as PHY if it is PHY-less
+ (fixed-link specified, presumably because it is connected to a MAC).
+ The effect of this property (in either its implicit or explicit form)
+ is:
+ - In the case of MII or RMII it specifies whether the SJA1105 port is a
+ clock source or sink for this interface (not applicable for RGMII
+ where there is a Tx and an Rx clock).
+ - In the case of RGMII it affects the behavior regarding internal
+ delays:
+ 1. If sja1105,role-mac is specified, and the phy-mode property is one
+ of "rgmii-id", "rgmii-txid" or "rgmii-rxid", then the entity
+ designated to apply the delay/clock skew necessary for RGMII
+ is the PHY. The SJA1105 MAC does not apply any internal delays.
+ 2. If sja1105,role-phy is specified, and the phy-mode property is one
+ of the above, the designated entity to apply the internal delays
+ is the SJA1105 MAC (if hardware-supported). This is only supported
+ by the second-generation (P/Q/R/S) hardware. On a first-generation
+ E or T device, it is an error to specify an RGMII phy-mode other
+ than "rgmii" for a port that is in fixed-link mode. In that case,
+ the clock skew must either be added by the MAC at the other end of
+ the fixed-link, or by PCB serpentine traces on the board.
+ These properties are required, for example, in the case where SJA1105
+ ports are at both ends of a MII/RMII PHY-less setup. One end would need
+ to have sja1105,role-mac, while the other sja1105,role-phy.
+
+See Documentation/devicetree/bindings/net/dsa/dsa.txt for the list of standard
+DSA required and optional properties.
+
+Other observations
+------------------
+
+The SJA1105 SPI interface requires a CS-to-CLK time (t2 in UM10944) of at least
+one half of t_CLK. At an SPI frequency of 1MHz, this means a minimum
+cs_sck_delay of 500ns. Ensuring that this SPI timing requirement is observed
+depends on the SPI bus master driver.
+
+Example
+-------
+
+Ethernet switch connected via SPI to the host, CPU port wired to enet2:
+
+arch/arm/boot/dts/ls1021a-tsn.dts:
+
+/* SPI controller of the LS1021 */
+&dspi0 {
+ sja1105@1 {
+ reg = <0x1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "nxp,sja1105";
+ spi-max-frequency = <4000000>;
+ fsl,spi-cs-sck-delay = <1000>;
+ fsl,spi-sck-cs-delay = <1000>;
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ port@0 {
+ /* ETH5 written on chassis */
+ label = "swp5";
+ phy-handle = <&rgmii_phy6>;
+ phy-mode = "rgmii";
+ reg = <0>;
+ /* Implicit "sja1105,role-mac;" */
+ };
+ port@1 {
+ /* ETH2 written on chassis */
+ label = "swp2";
+ phy-handle = <&rgmii_phy3>;
+ phy-mode = "rgmii";
+ reg = <1>;
+ /* Implicit "sja1105,role-mac;" */
+ };
+ port@2 {
+ /* ETH3 written on chassis */
+ label = "swp3";
+ phy-handle = <&rgmii_phy4>;
+ phy-mode = "rgmii";
+ reg = <2>;
+ /* Implicit "sja1105,role-mac;" */
+ };
+ port@3 {
+ /* ETH4 written on chassis */
+ phy-handle = <&rgmii_phy5>;
+ label = "swp4";
+ phy-mode = "rgmii";
+ reg = <3>;
+ /* Implicit "sja1105,role-mac;" */
+ };
+ port@4 {
+ /* Internal port connected to eth2 */
+ ethernet = <&enet2>;
+ phy-mode = "rgmii";
+ reg = <4>;
+ /* Implicit "sja1105,role-phy;" */
+ fixed-link {
+ speed = <1000>;
+ full-duplex;
+ };
+ };
+ };
+ };
+};
+
+/* MDIO controller of the LS1021 */
+&mdio0 {
+ /* BCM5464 */
+ rgmii_phy3: ethernet-phy@3 {
+ reg = <0x3>;
+ };
+ rgmii_phy4: ethernet-phy@4 {
+ reg = <0x4>;
+ };
+ rgmii_phy5: ethernet-phy@5 {
+ reg = <0x5>;
+ };
+ rgmii_phy6: ethernet-phy@6 {
+ reg = <0x6>;
+ };
+};
+
+/* Ethernet master port of the LS1021 */
+&enet2 {
+ phy-connection-type = "rgmii";
+ status = "ok";
+ fixed-link {
+ speed = <1000>;
+ full-duplex;
+ };
+};
+
--
2.17.1
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