net: dsa: qca8k: add support for qca8327 switch

qca8327 switch is a low tier version of the more recent qca8337.
It does share the same regs used by the qca8k driver and can be
supported with minimal change.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca8k.c

@@ -1524,6 +1524,7 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
 static int
 qca8k_sw_probe(struct mdio_device *mdiodev)
 {
+	const struct qca8k_match_data *data;
 	struct qca8k_priv *priv;
 	u32 id;
 
@@ -1551,6 +1552,11 @@ qca8k_sw_probe(struct mdio_device *mdiodev)
 		gpiod_set_value_cansleep(priv->reset_gpio, 0);
 	}
 
+	/* get the switches ID from the compatible */
+	data = of_device_get_match_data(&mdiodev->dev);
+	if (!data)
+		return -ENODEV;
+
 	/* read the switches ID register */
 	id = qca8k_read(priv, QCA8K_REG_MASK_CTRL);
 	if (id < 0)
@@ -1558,8 +1564,10 @@ qca8k_sw_probe(struct mdio_device *mdiodev)
 
 	id >>= QCA8K_MASK_CTRL_ID_S;
 	id &= QCA8K_MASK_CTRL_ID_M;
-	if (id != QCA8K_ID_QCA8337)
+	if (id != data->id) {
+		dev_err(&mdiodev->dev, "Switch id detected %x but expected %x", id, data->id);
 		return -ENODEV;
+	}
 
 	priv->ds = devm_kzalloc(&mdiodev->dev, sizeof(*priv->ds), GFP_KERNEL);
 	if (!priv->ds)
@@ -1624,9 +1632,18 @@ static int qca8k_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(qca8k_pm_ops,
 			 qca8k_suspend, qca8k_resume);
 
+static const struct qca8k_match_data qca832x = {
+	.id = QCA8K_ID_QCA8327,
+};
+
+static const struct qca8k_match_data qca833x = {
+	.id = QCA8K_ID_QCA8337,
+};
+
 static const struct of_device_id qca8k_of_match[] = {
-	{ .compatible = "qca,qca8334" },
+	{ .compatible = "qca,qca8327", .data = &qca832x },
-	{ .compatible = "qca,qca8337" },
+	{ .compatible = "qca,qca8334", .data = &qca833x },
+	{ .compatible = "qca,qca8337", .data = &qca833x },
 	{ /* sentinel */ },
 };
 

drivers/net/dsa/qca8k.h

@@ -15,6 +15,8 @@
 #define QCA8K_NUM_PORTS					7
 #define QCA8K_MAX_MTU					9000
 
+#define PHY_ID_QCA8327					0x004dd034
+#define QCA8K_ID_QCA8327				0x12
 #define PHY_ID_QCA8337					0x004dd036
 #define QCA8K_ID_QCA8337				0x13
 
@@ -213,6 +215,10 @@ struct ar8xxx_port_status {
 	int enabled;
 };
 
+struct qca8k_match_data {
+	u8 id;
+};
+
 struct qca8k_priv {
 	struct regmap *regmap;
 	struct mii_bus *bus;