net: dsa: microchip: dcb: add comments for DSCP related functions

All other functions are commented. Add missing comments to following
functions:
ksz_set_global_dscp_entry()
ksz_port_add_dscp_prio()
ksz_port_del_dscp_prio()
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240510053828.2412516-3-o.rempel@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/microchip/ksz_dcb.c

@@ -310,6 +310,17 @@ int ksz_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
 	return (data >> shift) & mask;
 }
 
+/**
+ * ksz_set_global_dscp_entry - Sets the global DSCP-to-priority mapping entry
+ * @dev: Pointer to the KSZ switch device structure
+ * @dscp: DSCP value for which to set the priority
+ * @ipm: Priority value to set
+ *
+ * This function sets the global DSCP-to-priority mapping entry for the
+ * specified DSCP value.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
 static int ksz_set_global_dscp_entry(struct ksz_device *dev, u8 dscp, u8 ipm)
 {
 	int reg, per_reg, shift;
@@ -377,6 +388,16 @@ static int ksz_init_global_dscp_map(struct ksz_device *dev)
 	return 0;
 }
 
+/**
+ * ksz_port_add_dscp_prio - Adds a DSCP-to-priority mapping entry for a port on
+ *			    a KSZ switch.
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to add the DSCP-to-priority mapping entry
+ * @dscp: DSCP value for which to add the priority
+ * @prio: Priority value to set
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
 int ksz_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
 {
 	struct ksz_device *dev = ds->priv;
@@ -387,6 +408,16 @@ int ksz_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
 	return ksz_set_global_dscp_entry(dev, dscp, prio);
 }
 
+/**
+ * ksz_port_del_dscp_prio - Deletes a DSCP-to-priority mapping entry for a port
+ *			    on a KSZ switch.
+ * @ds: Pointer to the DSA switch structure
+ * @port: Port number for which to delete the DSCP-to-priority mapping entry
+ * @dscp: DSCP value for which to delete the priority
+ * @prio: Priority value to delete
+ *
+ * Return: 0 on success, or a negative error code on failure
+ */
 int ksz_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp, u8 prio)
 {
 	struct ksz_device *dev = ds->priv;