[PATCH net-next v8 06/15] net: dsa: mt7530: Enable Rx sptag for EN7581 SoC

[Lorenzo Bianconi <lorenzo@kernel.org>]

Packet Processor Engine (PPE) module used for hw acceleration on EN7581
mac block, in order to properly parse packets, requires DSA untagged
packets on TX side and read DSA tag from DMA descriptor on RX side.
For this reason, enable RX Special Tag (SPTAG) for EN7581 SoC.
This is a preliminary patch to enable netfilter flowtable hw offloading
on EN7581 SoC.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/dsa/mt7530.c | 5 +++++
 drivers/net/dsa/mt7530.h | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 8422262febaf73821887e660c4db77047a91cffb..aaa36c27b0f9f6543db810a135b371bf1d326fa8 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2586,6 +2586,11 @@ mt7531_setup_common(struct dsa_switch *ds)
 	/* Allow mirroring frames received on the local port (monitor port). */
 	mt7530_set(priv, MT753X_AGC, LOCAL_EN);
 
+	/* Enable Special Tag for rx frames */
+	if (priv->id == ID_EN7581)
+		mt7530_write(priv, MT753X_CPORT_SPTAG_CFG,
+			     CPORT_SW2FE_STAG_EN | CPORT_FE2SW_STAG_EN);
+
 	/* Flush the FDB table */
 	ret = mt7530_fdb_cmd(priv, MT7530_FDB_FLUSH, NULL);
 	if (ret < 0)
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 448200689f492dcb73ef056d7284090c1c662e67..349d72a35771f35d478244ab29be1801b3466a5f 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -627,6 +627,10 @@ enum mt7531_xtal_fsel {
 #define  MT7531_GPIO12_RG_RXD3_MASK	GENMASK(19, 16)
 #define  MT7531_EXT_P_MDIO_12		(2 << 16)
 
+#define MT753X_CPORT_SPTAG_CFG		0x7c10
+#define  CPORT_SW2FE_STAG_EN		BIT(1)
+#define  CPORT_FE2SW_STAG_EN		BIT(0)
+
 /* Registers for LED GPIO control (MT7530 only)
  * All registers follow this pattern:
  * [ 2: 0]  port 0

-- 
2.48.1