net: stmmac: Add callbacks for DWC xpcs Energy Efficient Ethernet

Link xpcs callback functions for MAC to configure the xpcs EEE feature.

The clk_eee frequency is used to calculate the MULT_FACT_100NS. This is
to adjust the clock tic closer to 100ns.
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -429,6 +429,17 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 	plat->force_sf_dma_mode = 0;
 	plat->tso_en = 1;
 
+	/* Multiplying factor to the clk_eee_i clock time
+	 * period to make it closer to 100 ns. This value
+	 * should be programmed such that the clk_eee_time_period *
+	 * (MULT_FACT_100NS + 1) should be within 80 ns to 120 ns
+	 * clk_eee frequency is 19.2Mhz
+	 * clk_eee_time_period is 52ns
+	 * 52ns * (1 + 1) = 104ns
+	 * MULT_FACT_100NS = 1
+	 */
+	plat->mult_fact_100ns = 1;
+
 	plat->rx_sched_algorithm = MTL_RX_ALGORITHM_SP;
 
 	for (i = 0; i < plat->rx_queues_to_use; i++) {

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -623,6 +623,8 @@ struct stmmac_mmc_ops {
 	stmmac_do_callback(__priv, xpcs, link_up, __args)
 #define stmmac_xpcs_probe(__priv, __args...) \
 	stmmac_do_callback(__priv, xpcs, probe, __args)
+#define stmmac_xpcs_config_eee(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, config_eee, __args)
 
 struct stmmac_regs_off {
 	u32 ptp_off;

drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

@@ -720,6 +720,12 @@ static int stmmac_ethtool_op_set_eee(struct net_device *dev,
 		netdev_warn(priv->dev,
 			    "Setting EEE tx-lpi is not supported\n");
 
+	ret = stmmac_xpcs_config_eee(priv, &priv->hw->xpcs_args,
+				     priv->plat->mult_fact_100ns,
+				     edata->eee_enabled);
+	if (ret)
+		return ret;
+
 	if (!edata->eee_enabled)
 		stmmac_disable_eee_mode(priv);
 

include/linux/stmmac.h

@@ -223,6 +223,7 @@ struct plat_stmmacenet_data {
 	struct clk *clk_ptp_ref;
 	unsigned int clk_ptp_rate;
 	unsigned int clk_ref_rate;
+	unsigned int mult_fact_100ns;
 	s32 ptp_max_adj;
 	struct reset_control *stmmac_rst;
 	struct stmmac_axi *axi;