net: dsa: qca8k: add set_ageing_time support

qca8k support setting ageing time in step of 7s. Add support for it and
set the max value accepted of 7645m.
Documentation talks about support for 10000m but that values doesn't
make sense as the value doesn't match the max value in the reg.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca8k.c

@@ -1257,6 +1257,10 @@ qca8k_setup(struct dsa_switch *ds)
 	/* We don't have interrupts for link changes, so we need to poll */
 	ds->pcs_poll = true;
 
+	/* Set min a max ageing value supported */
+	ds->ageing_time_min = 7000;
+	ds->ageing_time_max = 458745000;
+
 	return 0;
 }
 
@@ -1796,6 +1800,26 @@ qca8k_port_fast_age(struct dsa_switch *ds, int port)
 	mutex_unlock(&priv->reg_mutex);
 }
 
+static int
+qca8k_set_ageing_time(struct dsa_switch *ds, unsigned int msecs)
+{
+	struct qca8k_priv *priv = ds->priv;
+	unsigned int secs = msecs / 1000;
+	u32 val;
+
+	/* AGE_TIME reg is set in 7s step */
+	val = secs / 7;
+
+	/* Handle case with 0 as val to NOT disable
+	 * learning
+	 */
+	if (!val)
+		val = 1;
+
+	return regmap_update_bits(priv->regmap, QCA8K_REG_ATU_CTRL, QCA8K_ATU_AGE_TIME_MASK,
+				  QCA8K_ATU_AGE_TIME(val));
+}
+
 static int
 qca8k_port_enable(struct dsa_switch *ds, int port,
 		  struct phy_device *phy)
@@ -1995,6 +2019,7 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
 	.get_strings		= qca8k_get_strings,
 	.get_ethtool_stats	= qca8k_get_ethtool_stats,
 	.get_sset_count		= qca8k_get_sset_count,
+	.set_ageing_time	= qca8k_set_ageing_time,
 	.get_mac_eee		= qca8k_get_mac_eee,
 	.set_mac_eee		= qca8k_set_mac_eee,
 	.port_enable		= qca8k_port_enable,

drivers/net/dsa/qca8k.h

@@ -175,6 +175,9 @@
 #define   QCA8K_VTU_FUNC1_BUSY				BIT(31)
 #define   QCA8K_VTU_FUNC1_VID_MASK			GENMASK(27, 16)
 #define   QCA8K_VTU_FUNC1_FULL				BIT(4)
+#define QCA8K_REG_ATU_CTRL				0x618
+#define   QCA8K_ATU_AGE_TIME_MASK			GENMASK(15, 0)
+#define   QCA8K_ATU_AGE_TIME(x)				FIELD_PREP(QCA8K_ATU_AGE_TIME_MASK, (x))
 #define QCA8K_REG_GLOBAL_FW_CTRL0			0x620
 #define   QCA8K_GLOBAL_FW_CTRL0_CPU_PORT_EN		BIT(10)
 #define QCA8K_REG_GLOBAL_FW_CTRL1			0x624