stmmac: Read tx-fifo-depth and rx-fifo-depth from the devicetree

Read the tx-fifo-depth and rx-fifo-depth from the devicetree. The Synopsys
stmmac controller fifos are configurable per product instance, and the fifo
sizes are needed to configure certain features correctly such as flow control.

Signed-off-by: Vince Bridgers <vbridger@opensource.altera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index f9b42f1..705bbdf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -181,6 +181,10 @@
 				     sizeof(struct stmmac_mdio_bus_data),
 				     GFP_KERNEL);
 
+	of_property_read_u32(np, "tx-fifo-depth", &plat->tx_fifo_size);
+
+	of_property_read_u32(np, "rx-fifo-depth", &plat->rx_fifo_size);
+
 	plat->force_sf_dma_mode =
 		of_property_read_bool(np, "snps,force_sf_dma_mode");
 
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index cd63851..7f484a2 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -114,6 +114,8 @@
 	int maxmtu;
 	int multicast_filter_bins;
 	int unicast_filter_entries;
+	int tx_fifo_size;
+	int rx_fifo_size;
 	void (*fix_mac_speed)(void *priv, unsigned int speed);
 	void (*bus_setup)(void __iomem *ioaddr);
 	void *(*setup)(struct platform_device *pdev);