phy: ti: phy-j721e-wiz: fix usxgmii configuration

Commit b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in
wiz driver") added support for USXGMII mode. In doing so, P0_REFCLK_SEL
was set to "pcs_mac_clk_divx1_ln_0" (0x3) and P0_STANDARD_MODE was set to
LANE_MODE_GEN1, which results in a data rate of 5.15625 Gbps. However,
since the USXGMII mode can support up to 10.3125 Gbps data rate, the
aforementioned fields should be set to "pcs_mac_clk_divx0_ln_0" (0x2) and
LANE_MODE_GEN2 respectively. The signal corresponding to the USXGMII lane
of the SERDES has been measured as 5 Gbps without the change and 10 Gbps
with the change. Hence, fix the configuration accordingly to support
USXGMII up to 10G.

Fixes: b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in wiz driver")
Signed-off-by: Siddharth Vadapalli <[e-mail]>
Reviewed-by: Roger Quadros <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/ti/phy-j721e-wiz.c

···
 		} else if (wiz->lane_phy_type[i] == PHY_TYPE_USXGMII) {
 			ret = regmap_field_write(wiz->p0_mac_src_sel[i], 0x3);
 			ret = regmap_field_write(wiz->p0_rxfclk_sel[i], 0x3);
-			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x3);
-			mode = LANE_MODE_GEN1;
+			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x2);
+			mode = LANE_MODE_GEN2;
 		} else {
 			continue;
 		}