[PATCH 6/7] [DSA] tell GDMA when we are turning on the special tag

[Frank Wunderlich]

based on
https://github.com/openwrt/openwrt/blob/master/target/linux/mediatek/patches-4.14/0044-net-next-dsa-mediatek-tell-GDMA-when-we-are-turning-.patch

Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
---
 drivers/net/dsa/mt7530.c | 6 ++++++
 drivers/net/dsa/mt7530.h | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 441320d4d779..83669f53cb36 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -681,6 +681,12 @@ mt7530_cpu_port_enable(struct mt7530_priv *priv,
 	mt7530_write(priv, MT7530_PVC_P(port),
 		     PORT_SPEC_TAG);
 
+	/* Enable Mediatek header mode on the GMAC that the cpu port
+	 * connects to
+	 */
+	regmap_write_bits(priv->ethernet, MTK_GDMA_FWD_CFG(port),
+			  GDMA_SPEC_TAG, GDMA_SPEC_TAG);
+
 	/* Setup the MAC by default for the cpu port */
 	mt7530_write(priv, MT7530_PMCR_P(port), PMCR_CPUP_LINK);
 
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index d9b407a22a58..310f2536175b 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -23,6 +23,10 @@
 
 #define TRGMII_BASE(x)			(0x10000 + (x))
 
+/* Registers for GDMA configuration access */
+#define MTK_GDMA_FWD_CFG(x)		(0x500 + (x * 0x1000))
+#define GDMA_SPEC_TAG			BIT(24)
+
 /* Registers to ethsys access */
 #define ETHSYS_CLKCFG0			0x2c
 #define  ETHSYS_TRGMII_CLK_SEL362_5	BIT(11)
-- 
2.17.1