[PATCH v3] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[Siddharth Vadapalli]

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 <s-vadapalli at ti.com>
Reviewed-by: Roger Quadros <rogerq at kernel.org>
---

Hello,

This patch is based on commit
09f6b0c8904b Merge tag 'linux_kselftest-fixes-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
of the master branch of Mainline Linux.

v2:
https://lore.kernel.org/r/20240930095745.3007057-1-s-vadapalli@ti.com/
Changes since v2:
- Rebased to commit 09f6b0c8904b of Mainline Linux.
- Updated commit message based on Roger's feedback.
- Collected Reviewed-by tag from
  Roger Quadros <rogerq at kernel.org>

v1:
https://lore.kernel.org/r/20240910091714.1082191-1-s-vadapalli@ti.com/
Changes since v1:
- Rebased to Linux 6.12-rc1.

 drivers/phy/ti/phy-j721e-wiz.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
index a6c0c5607ffd..c6e846d385d2 100644
--- a/drivers/phy/ti/phy-j721e-wiz.c
+++ b/drivers/phy/ti/phy-j721e-wiz.c
@@ -450,8 +450,8 @@ static int wiz_mode_select(struct wiz *wiz)
 		} 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;
 		}
-- 
2.40.1