Device tree aware EMAC driver

Based on BenH's earlier work, this is a new version of the EMAC driver
for the built-in ethernet found on PowerPC 4xx embedded CPUs.  The
same ASIC is also found in the Axon bridge chip.  This new version is
designed to work in the arch/powerpc tree, using the device tree to
probe the device, rather than the old and ugly arch/ppc OCP layer.

This driver is designed to sit alongside the old driver (that lies in
drivers/net/ibm_emac and this one in drivers/net/ibm_newemac).  The
old driver is left in place to support arch/ppc until arch/ppc itself
reaches its final demise (not too long now, with luck).

This driver still has a number of things that could do with cleaning
up, but I think they can be fixed up after merging.  Specifically:
	- Should be adjusted to properly use the dma mapping API.
Axon needs this.
	- Probe logic needs reworking, in conjuction with the general
probing code for of_platform devices.  The dependencies here between
EMAC, MAL, ZMII etc. make this complicated.  At present, it usually
works, because we initialize and register the sub-drivers before the
EMAC driver itself, and (being in driver code) runs after the devices
themselves have been instantiated from the device tree.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/ibm_emac/Kconfig

@@ -0,0 +1,70 @@
+config IBM_EMAC
+	tristate "PowerPC 4xx on-chip Ethernet support"
+	depends on 4xx && !PPC_MERGE
+	help
+	  This driver supports the PowerPC 4xx EMAC family of on-chip
+          Ethernet controllers.
+
+config IBM_EMAC_RXB
+	int "Number of receive buffers"
+	depends on IBM_EMAC
+	default "128"
+
+config IBM_EMAC_TXB
+	int "Number of transmit buffers"
+	depends on IBM_EMAC
+	default "64"
+
+config IBM_EMAC_POLL_WEIGHT
+	int "MAL NAPI polling weight"
+	depends on IBM_EMAC
+	default "32"
+
+config IBM_EMAC_RX_COPY_THRESHOLD
+	int "RX skb copy threshold (bytes)"
+	depends on IBM_EMAC
+	default "256"
+
+config IBM_EMAC_RX_SKB_HEADROOM
+	int "Additional RX skb headroom (bytes)"
+	depends on IBM_EMAC
+	default "0"
+	help
+	  Additional receive skb headroom. Note, that driver
+	  will always reserve at least 2 bytes to make IP header
+	  aligned, so usually there is no need to add any additional
+	  headroom.
+
+	  If unsure, set to 0.
+
+config IBM_EMAC_PHY_RX_CLK_FIX
+	bool "PHY Rx clock workaround"
+	depends on IBM_EMAC && (405EP || 440GX || 440EP || 440GR)
+	help
+	  Enable this if EMAC attached to a PHY which doesn't generate
+	  RX clock if there is no link, if this is the case, you will
+	  see "TX disable timeout" or "RX disable timeout" in the system
+	  log.
+
+	  If unsure, say N.
+
+config IBM_EMAC_DEBUG
+	bool "Debugging"
+	depends on IBM_EMAC
+	default n
+
+config IBM_EMAC_ZMII
+	bool
+	depends on IBM_EMAC && (NP405H || NP405L || 44x)
+	default y
+
+config IBM_EMAC_RGMII
+	bool
+	depends on IBM_EMAC && 440GX
+	default y
+
+config IBM_EMAC_TAH
+	bool
+	depends on IBM_EMAC && 440GX
+	default y
+