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From:   Ansuel Smith <ansuelsmth@gmail.com>
To:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        netdev@vger.kernel.org (open list:NETWORKING DRIVERS),
        devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED
        DEVICE TREE BINDINGS), linux-kernel@vger.kernel.org (open list)
Cc:     Ansuel Smith <ansuelsmth@gmail.com>
Subject: [RFC PATCH net-next v5 16/25] net: dsa: qca8k: make rgmii delay configurable
Date:   Tue, 11 May 2021 04:04:51 +0200
Message-Id: <20210511020500.17269-17-ansuelsmth@gmail.com>
In-Reply-To: <20210511020500.17269-1-ansuelsmth@gmail.com>
References: <20210511020500.17269-1-ansuelsmth@gmail.com>
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The legacy qsdk code used a different delay instead of the max value.
Qsdk use 1 ms for rx and 2 ms for tx. Make these values configurable
using the standard rx/tx-internal-delay-ps ethernet binding and apply
qsdk values by default. The connected gmac doesn't add any delay so no
additional delay is added to tx/rx.
On this switch the delay is actually in ms so value should be in the
1000 order. Any value converted from ps to ms by deviding it by 1000
as the switch max value for delay is 3ms.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca8k.c | 82 ++++++++++++++++++++++++++++++++++++++++-
 drivers/net/dsa/qca8k.h | 11 +++---
 2 files changed, 86 insertions(+), 7 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index cc9ab35f8b17..ff46d253e345 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -777,6 +777,68 @@ qca8k_setup_mdio_bus(struct qca8k_priv *priv)
 	return 0;
 }
 
+static int
+qca8k_setup_of_rgmii_delay(struct qca8k_priv *priv)
+{
+	struct device_node *port_dn;
+	phy_interface_t mode;
+	struct dsa_port *dp;
+	u32 val;
+
+	/* CPU port is already checked */
+	dp = dsa_to_port(priv->ds, 0);
+
+	port_dn = dp->dn;
+
+	/* Check if port 0 is set to the correct type */
+	of_get_phy_mode(port_dn, &mode);
+	if (mode != PHY_INTERFACE_MODE_RGMII_ID &&
+	    mode != PHY_INTERFACE_MODE_RGMII_RXID &&
+	    mode != PHY_INTERFACE_MODE_RGMII_TXID) {
+		return 0;
+	}
+
+	switch (mode) {
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		if (of_property_read_u32(port_dn, "rx-internal-delay-ps", &val))
+			val = 2;
+		else
+			/* Switch regs accept value in ms, convert ps to ms */
+			val = val / 1000;
+
+		if (val > QCA8K_MAX_DELAY) {
+			dev_err(priv->dev, "rgmii rx delay is limited to a max value of 3ms, setting to the max value");
+			val = 3;
+		}
+
+		priv->rgmii_rx_delay = val;
+		/* Stop here if we need to check only for rx delay */
+		if (mode != PHY_INTERFACE_MODE_RGMII_ID)
+			break;
+
+		fallthrough;
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		if (of_property_read_u32(port_dn, "tx-internal-delay-ps", &val))
+			val = 1;
+		else
+			/* Switch regs accept value in ms, convert ps to ms */
+			val = val / 1000;
+
+		if (val > QCA8K_MAX_DELAY) {
+			dev_err(priv->dev, "rgmii tx delay is limited to a max value of 3ms, setting to the max value");
+			val = 3;
+		}
+
+		priv->rgmii_tx_delay = val;
+		break;
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
 static int
 qca8k_setup(struct dsa_switch *ds)
 {
@@ -802,6 +864,10 @@ qca8k_setup(struct dsa_switch *ds)
 	if (ret)
 		return ret;
 
+	ret = qca8k_setup_of_rgmii_delay(priv);
+	if (ret)
+		return ret;
+
 	/* Enable CPU Port */
 	ret = qca8k_reg_set(priv, QCA8K_REG_GLOBAL_FW_CTRL0,
 			    QCA8K_GLOBAL_FW_CTRL0_CPU_PORT_EN);
@@ -970,6 +1036,8 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 	case 0: /* 1st CPU port */
 		if (state->interface != PHY_INTERFACE_MODE_RGMII &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII_ID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_TXID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_RXID &&
 		    state->interface != PHY_INTERFACE_MODE_SGMII)
 			return;
 
@@ -985,6 +1053,8 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 	case 6: /* 2nd CPU port / external PHY */
 		if (state->interface != PHY_INTERFACE_MODE_RGMII &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII_ID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_TXID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_RXID &&
 		    state->interface != PHY_INTERFACE_MODE_SGMII &&
 		    state->interface != PHY_INTERFACE_MODE_1000BASEX)
 			return;
@@ -1008,14 +1078,18 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 		qca8k_write(priv, reg, QCA8K_PORT_PAD_RGMII_EN);
 		break;
 	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
 		/* RGMII_ID needs internal delay. This is enabled through
 		 * PORT5_PAD_CTRL for all ports, rather than individual port
 		 * registers
 		 */
 		qca8k_write(priv, reg,
 			    QCA8K_PORT_PAD_RGMII_EN |
-			    QCA8K_PORT_PAD_RGMII_TX_DELAY(QCA8K_MAX_DELAY) |
-			    QCA8K_PORT_PAD_RGMII_RX_DELAY(QCA8K_MAX_DELAY));
+			    QCA8K_PORT_PAD_RGMII_TX_DELAY(priv->rgmii_tx_delay) |
+			    QCA8K_PORT_PAD_RGMII_RX_DELAY(priv->rgmii_rx_delay) |
+			    QCA8K_PORT_PAD_RGMII_TX_DELAY_EN |
+			    QCA8K_PORT_PAD_RGMII_RX_DELAY_EN);
 		/* QCA8337 requires to set rgmii rx delay */
 		if (priv->switch_id == QCA8K_ID_QCA8337)
 			qca8k_write(priv, QCA8K_REG_PORT5_PAD_CTRL,
@@ -1073,6 +1147,8 @@ qca8k_phylink_validate(struct dsa_switch *ds, int port,
 		if (state->interface != PHY_INTERFACE_MODE_NA &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII_ID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_TXID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_RXID &&
 		    state->interface != PHY_INTERFACE_MODE_SGMII)
 			goto unsupported;
 		break;
@@ -1090,6 +1166,8 @@ qca8k_phylink_validate(struct dsa_switch *ds, int port,
 		if (state->interface != PHY_INTERFACE_MODE_NA &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII &&
 		    state->interface != PHY_INTERFACE_MODE_RGMII_ID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_TXID &&
+		    state->interface != PHY_INTERFACE_MODE_RGMII_RXID &&
 		    state->interface != PHY_INTERFACE_MODE_SGMII &&
 		    state->interface != PHY_INTERFACE_MODE_1000BASEX)
 			goto unsupported;
diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
index 338277978ec0..a878486d9bcd 100644
--- a/drivers/net/dsa/qca8k.h
+++ b/drivers/net/dsa/qca8k.h
@@ -38,12 +38,11 @@
 #define QCA8K_REG_PORT5_PAD_CTRL			0x008
 #define QCA8K_REG_PORT6_PAD_CTRL			0x00c
 #define   QCA8K_PORT_PAD_RGMII_EN			BIT(26)
-#define   QCA8K_PORT_PAD_RGMII_TX_DELAY(x)		\
-						((0x8 + (x & 0x3)) << 22)
-#define   QCA8K_PORT_PAD_RGMII_RX_DELAY(x)		\
-						((0x10 + (x & 0x3)) << 20)
-#define   QCA8K_MAX_DELAY				3
+#define   QCA8K_PORT_PAD_RGMII_TX_DELAY(x)		((x) << 22)
+#define   QCA8K_PORT_PAD_RGMII_RX_DELAY(x)		((x) << 20)
+#define	  QCA8K_PORT_PAD_RGMII_TX_DELAY_EN		BIT(25)
 #define   QCA8K_PORT_PAD_RGMII_RX_DELAY_EN		BIT(24)
+#define   QCA8K_MAX_DELAY				3
 #define   QCA8K_PORT_PAD_SGMII_EN			BIT(7)
 #define QCA8K_REG_PWS					0x010
 #define   QCA8K_PWS_SERDES_AEN_DIS			BIT(7)
@@ -254,6 +253,8 @@ struct qca8k_match_data {
 struct qca8k_priv {
 	u8 switch_id;
 	u8 switch_revision;
+	u8 rgmii_tx_delay;
+	u8 rgmii_rx_delay;
 	struct regmap *regmap;
 	struct mii_bus *bus;
 	struct ar8xxx_port_status port_sts[QCA8K_NUM_PORTS];
-- 
2.30.2