[LEDE-DEV] [PATCH v2] ar8327: Add workarounds for AR8337 switch.

[Vittorio Gambaletta (VittGam)]

RGMII RX delay setting needs to be always specified for AR8337 to
avoid port 5 RX hang on high traffic / flood conditions.

Also, the HOL registers that set per-port and per-packet-priority
buffer sizes are updated with the reduced values suggested by the
QCA switch team.

Finally, AR8327 reserved register fixups are disabled for the AR8337.

This patch is adapted from the Code Aurora QSDK, but with magic
values mapped to proper defines.

Signed-off-by: Vittorio Gambaletta <openwrt at vittgam.net>

---
 .../linux/generic/files/drivers/net/phy/ar8327.c   |   43 +++++++++++++++++++-
 .../linux/generic/files/drivers/net/phy/ar8327.h   |   21 ++++++++++
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/target/linux/generic/files/drivers/net/phy/ar8327.c b/target/linux/generic/files/drivers/net/phy/ar8327.c
index 8e67f4b..97cee29 100644
--- a/target/linux/generic/files/drivers/net/phy/ar8327.c
+++ b/target/linux/generic/files/drivers/net/phy/ar8327.c
@@ -506,6 +506,14 @@ ar8327_hw_config_pdata(struct ar8xxx_priv *priv,
 	ar8xxx_write(priv, AR8327_REG_PAD0_MODE, t);
 
 	t = ar8327_get_pad_cfg(pdata->pad5_cfg);
+	if (chip_is_ar8337(priv)) {
+		/*
+		 * Workaround: RGMII RX delay setting needs to be
+		 * always specified for AR8337 to avoid port 5
+		 * RX hang on high traffic / flood conditions
+		 */
+		t |= AR8327_PAD_RGMII_RXCLK_DELAY_EN;
+	}
 	ar8xxx_write(priv, AR8327_REG_PAD5_MODE, t);
 	t = ar8327_get_pad_cfg(pdata->pad6_cfg);
 	ar8xxx_write(priv, AR8327_REG_PAD6_MODE, t);
@@ -670,6 +678,39 @@ ar8327_init_globals(struct ar8xxx_priv *priv)
 	/* Disable EEE on all phy's due to stability issues */
 	for (i = 0; i < AR8XXX_NUM_PHYS; i++)
 		data->eee[i] = false;
+
+	if (chip_is_ar8337(priv)) {
+		/* Update HOL registers with values suggested by QCA switch team */
+		for (i = 0; i < AR8327_NUM_PORTS; i++) {
+			if (i == AR8216_PORT_CPU || i == 5 || i == 6) {
+				t = 0x3 << AR8327_PORT_HOL_CTRL0_EG_PRI0_BUF_S;
+				t |= 0x4 << AR8327_PORT_HOL_CTRL0_EG_PRI1_BUF_S;
+				t |= 0x4 << AR8327_PORT_HOL_CTRL0_EG_PRI2_BUF_S;
+				t |= 0x4 << AR8327_PORT_HOL_CTRL0_EG_PRI3_BUF_S;
+				t |= 0x6 << AR8327_PORT_HOL_CTRL0_EG_PRI4_BUF_S;
+				t |= 0x8 << AR8327_PORT_HOL_CTRL0_EG_PRI5_BUF_S;
+				t |= 0x1e << AR8327_PORT_HOL_CTRL0_EG_PORT_BUF_S;
+			} else {
+				t = 0x3 << AR8327_PORT_HOL_CTRL0_EG_PRI0_BUF_S;
+				t |= 0x4 << AR8327_PORT_HOL_CTRL0_EG_PRI1_BUF_S;
+				t |= 0x6 << AR8327_PORT_HOL_CTRL0_EG_PRI2_BUF_S;
+				t |= 0x8 << AR8327_PORT_HOL_CTRL0_EG_PRI3_BUF_S;
+				t |= 0x19 << AR8327_PORT_HOL_CTRL0_EG_PORT_BUF_S;
+			}
+			ar8xxx_write(priv, AR8327_REG_PORT_HOL_CTRL0(i), t);
+
+			t = 0x6 << AR8327_PORT_HOL_CTRL1_ING_BUF_S;
+			t |= AR8327_PORT_HOL_CTRL1_EG_PRI_BUF_EN;
+			t |= AR8327_PORT_HOL_CTRL1_EG_PORT_BUF_EN;
+			t |= AR8327_PORT_HOL_CTRL1_WRED_EN;
+			ar8xxx_rmw(priv, AR8327_REG_PORT_HOL_CTRL1(i),
+				   AR8327_PORT_HOL_CTRL1_ING_BUF |
+				   AR8327_PORT_HOL_CTRL1_EG_PRI_BUF_EN |
+				   AR8327_PORT_HOL_CTRL1_EG_PORT_BUF_EN |
+				   AR8327_PORT_HOL_CTRL1_WRED_EN,
+				   t);
+		}
+	}
 }
 
 static void
@@ -1397,7 +1438,7 @@ const struct ar8xxx_chip ar8327_chip = {
 	.atu_flush_port = ar8327_atu_flush_port,
 	.vtu_flush = ar8327_vtu_flush,
 	.vtu_load_vlan = ar8327_vtu_load_vlan,
-	.phy_fixup = ar8327_phy_fixup,
+	//.phy_fixup = ar8337_phy_fixup, // not needed at the moment
 	.set_mirror_regs = ar8327_set_mirror_regs,
 	.get_arl_entry = ar8327_get_arl_entry,
 	.sw_hw_apply = ar8327_sw_hw_apply,
diff --git a/target/linux/generic/files/drivers/net/phy/ar8327.h b/target/linux/generic/files/drivers/net/phy/ar8327.h
index 7bce18b..828dd28 100644
--- a/target/linux/generic/files/drivers/net/phy/ar8327.h
+++ b/target/linux/generic/files/drivers/net/phy/ar8327.h
@@ -272,7 +272,28 @@
 
 #define AR8327_REG_PORT_PRIO(_i)		(0x664 + (_i) * 0xc)
 
+#define AR8327_REG_PORT_HOL_CTRL0(_i)		(0x970 + (_i) * 0x8)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI0_BUF	BITS(0, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI0_BUF_S	0
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI1_BUF	BITS(4, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI1_BUF_S	4
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI2_BUF	BITS(8, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI2_BUF_S	8
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI3_BUF	BITS(12, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI3_BUF_S	12
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI4_BUF	BITS(16, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI4_BUF_S	16
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI5_BUF	BITS(20, 4)
+#define   AR8327_PORT_HOL_CTRL0_EG_PRI5_BUF_S	20
+#define   AR8327_PORT_HOL_CTRL0_EG_PORT_BUF	BITS(24, 6)
+#define   AR8327_PORT_HOL_CTRL0_EG_PORT_BUF_S	24
+
 #define AR8327_REG_PORT_HOL_CTRL1(_i)		(0x974 + (_i) * 0x8)
+#define   AR8327_PORT_HOL_CTRL1_ING_BUF		BITS(0, 4)
+#define   AR8327_PORT_HOL_CTRL1_ING_BUF_S	0
+#define   AR8327_PORT_HOL_CTRL1_EG_PRI_BUF_EN	BIT(6)
+#define   AR8327_PORT_HOL_CTRL1_EG_PORT_BUF_EN	BIT(7)
+#define   AR8327_PORT_HOL_CTRL1_WRED_EN		BIT(8)
 #define   AR8327_PORT_HOL_CTRL1_EG_MIRROR_EN	BIT(16)
 
 #define AR8337_PAD_MAC06_EXCHANGE_EN		BIT(31)