stmmac: Add properties for transmit and receive fifo sizes

The Synopsys stmmac fifo sizes are configurable, and need to be known
in order to configure certain controller features. This patch adds
tx-fifo-depth and rx-fifo-depth properties to the stmmac document
file.

Signed-off-by: Vince Bridgers <vbridger@opensource.altera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Vince Bridgers

Documentation/devicetree/bindings/net/ethernet.txt

@@ -0,0 +1,31 @@
+The following properties are common to the Ethernet controllers:
+
+- local-mac-address: array of 6 bytes, specifies the MAC address that was
+  assigned to the network device;
+- mac-address: array of 6 bytes, specifies the MAC address that was last used by
+  the boot program; should be used in cases where the MAC address assigned to
+  the device by the boot program is different from the "local-mac-address"
+  property;
+- max-speed: number, specifies maximum speed in Mbit/s supported by the device;
+- max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than
+  the maximum frame size (there's contradiction in ePAPR).
+- phy-mode: string, operation mode of the PHY interface; supported values are
+  "mii", "gmii", "sgmii", "qsgmii", "tbi", "rev-mii", "rmii", "rgmii", "rgmii-id",
+  "rgmii-rxid", "rgmii-txid", "rtbi", "smii", "xgmii"; this is now a de-facto
+  standard property;
+- phy-connection-type: the same as "phy-mode" property but described in ePAPR;
+- phy-handle: phandle, specifies a reference to a node representing a PHY
+  device; this property is described in ePAPR and so preferred;
+- phy: the same as "phy-handle" property, not recommended for new bindings.
+- phy-device: the same as "phy-handle" property, not recommended for new
+  bindings.
+- rx-fifo-depth: the size of the controller's receive fifo in bytes. This
+  is used for components that can have configurable receive fifo sizes,
+  and is useful for determining certain configuration settings such as
+  flow control thresholds.
+- tx-fifo-depth: the size of the controller's transmit fifo in bytes. This
+  is used for components that can have configurable fifo sizes.
+
+Child nodes of the Ethernet controller are typically the individual PHY devices
+connected via the MDIO bus (sometimes the MDIO bus controller is separate).
+They are described in the phy.txt file in this same directory.

Documentation/devicetree/bindings/net/stmmac.txt

@@ -19,11 +19,21 @@ Required properties:
 
 Optional properties:
 - mac-address: 6 bytes, mac address
-- snps,max-mtu          Maximum mtu size permitted. Useful since
-                        the Synopsys EMAC transmit and receive fifos are
-                        configurable by Core Consultant, resulting in
-                        different maximum mtus for different instances
-                        of the device.
+- resets: Should contain a phandle to the STMMAC reset signal, if any
+- reset-names: Should contain the reset signal name "stmmaceth", if a
+	reset phandle is given
+- max-frame-size: See ethernet.txt file in the same directory
+- clocks: If present, the first clock should be the GMAC main clock,
+  further clocks may be specified in derived bindings.
+- clock-names: One name for each entry in the clocks property, the
+  first one should be "stmmaceth".
+- clk_ptp_ref: this is the PTP reference clock; in case of the PTP is
+  available this clock is used for programming the Timestamp Addend Register.
+  If not passed then the system clock will be used and this is fine on some
+  platforms.
+- snps,burst_len: The AXI burst lenth value of the AXI BUS MODE register.
+- tx-fifo-depth: See ethernet.txt file in the same directory
+- rx-fifo-depth: See ethernet.txt file in the same directory
 
 Examples:
 
@@ -38,4 +48,8 @@ Examples:
 		snps,max-mtu = <4062>;
 		snps,multicast-filter-bins = <256>;
 		snps,perfect-filter-entries = <128>;
+		rx-fifo-depth = <16384>;
+		tx-fifo-depth = <16384>;
+		clocks = <&clock>;
+		clock-names = "stmmaceth";
 	};