net: dsa: qca8k: make mib autocast feature optional

Some switch may not support mib autocast feature and require the legacy
way of reading the regs directly.
Make the mib autocast feature optional and permit to declare support for
it using match_data struct in a dedicated qca8k_info_ops struct.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/qca/qca8k.c

@@ -2104,8 +2104,8 @@ qca8k_get_ethtool_stats(struct dsa_switch *ds, int port,
 	u32 hi = 0;
 	int ret;
 
-	if (priv->mgmt_master &&
-	    qca8k_get_ethtool_stats_eth(ds, port, data) > 0)
+	if (priv->mgmt_master && priv->info->ops->autocast_mib &&
+	    priv->info->ops->autocast_mib(ds, port, data) > 0)
 		return;
 
 	for (i = 0; i < priv->info->mib_count; i++) {
@@ -3243,20 +3243,27 @@ static int qca8k_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(qca8k_pm_ops,
 			 qca8k_suspend, qca8k_resume);
 
+static const struct qca8k_info_ops qca8xxx_ops = {
+	.autocast_mib = qca8k_get_ethtool_stats_eth,
+};
+
 static const struct qca8k_match_data qca8327 = {
 	.id = QCA8K_ID_QCA8327,
 	.reduced_package = true,
 	.mib_count = QCA8K_QCA832X_MIB_COUNT,
+	.ops = &qca8xxx_ops,
 };
 
 static const struct qca8k_match_data qca8328 = {
 	.id = QCA8K_ID_QCA8327,
 	.mib_count = QCA8K_QCA832X_MIB_COUNT,
+	.ops = &qca8xxx_ops,
 };
 
 static const struct qca8k_match_data qca833x = {
 	.id = QCA8K_ID_QCA8337,
 	.mib_count = QCA8K_QCA833X_MIB_COUNT,
+	.ops = &qca8xxx_ops,
 };
 
 static const struct of_device_id qca8k_of_match[] = {

drivers/net/dsa/qca/qca8k.h

@@ -324,10 +324,15 @@ enum qca8k_mid_cmd {
 	QCA8K_MIB_CAST = 3,
 };
 
+struct qca8k_info_ops {
+	int (*autocast_mib)(struct dsa_switch *ds, int port, u64 *data);
+};
+
 struct qca8k_match_data {
 	u8 id;
 	bool reduced_package;
 	u8 mib_count;
+	const struct qca8k_info_ops *ops;
 };
 
 enum {