[PATCH V4 2/2] phy: ti: j721e-wiz: Add support to enable LN23 Type-C swap

[Sinthu Raja]

From: Sinthu Raja <sinthu.raja at ti.com>

The WIZ acts as a wrapper for SerDes and has Lanes 0 and 2 reserved
for USB for type-C lane swap if Lane 1 and Lane 3 are linked to the
USB PHY that is integrated into the SerDes IP. The WIZ control register
has to be configured to support this lane swap feature.

The support for swapping lanes 2 and 3 is missing and therefore
add support to configure the control register to swap between
lanes 2 and 3 if PHY type is USB.

Signed-off-by: Sinthu Raja <sinthu.raja at ti.com>
Reviewed-by: Roger Quadros <rogerq at kernel.org>
---

Changes in V4:
============
- Add Review tag.
- Fix checkpatch CHECK errors.
 * Remove unnecessary paranthesis.
 * Avoid logical continuations in multiple lines.

Changes in V3:
=============
Address review comments:
- Update comment to mention the LN23 SWAP along with the LN10

Changes in V2:
=============
Address review comments:
- Update commit description.
- Rename enum variable name from wiz_lane_typec_swap_mode to wiz_typec_master_lane.
- Rename enumerators name specific to list of master lanes used for lane swapping.
- Add inline comments.

 drivers/phy/ti/phy-j721e-wiz.c | 38 +++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
index b5c1b82e99a6..1b83c98a78f0 100644
--- a/drivers/phy/ti/phy-j721e-wiz.c
+++ b/drivers/phy/ti/phy-j721e-wiz.c
@@ -58,6 +58,14 @@ enum wiz_lane_standard_mode {
 	LANE_MODE_GEN4,
 };
 
+/*
+ * List of master lanes used for lane swapping
+ */
+enum wiz_typec_master_lane {
+	LANE0 = 0,
+	LANE2 = 2,
+};
+
 enum wiz_refclk_mux_sel {
 	PLL0_REFCLK,
 	PLL1_REFCLK,
@@ -194,6 +202,9 @@ static const struct reg_field p_mac_div_sel1[WIZ_MAX_LANES] = {
 static const struct reg_field typec_ln10_swap =
 					REG_FIELD(WIZ_SERDES_TYPEC, 30, 30);
 
+static const struct reg_field typec_ln23_swap =
+					REG_FIELD(WIZ_SERDES_TYPEC, 31, 31);
+
 struct wiz_clk_mux {
 	struct clk_hw		hw;
 	struct regmap_field	*field;
@@ -367,6 +378,7 @@ struct wiz {
 	struct regmap_field	*mux_sel_field[WIZ_MUX_NUM_CLOCKS];
 	struct regmap_field	*div_sel_field[WIZ_DIV_NUM_CLOCKS_16G];
 	struct regmap_field	*typec_ln10_swap;
+	struct regmap_field	*typec_ln23_swap;
 	struct regmap_field	*sup_legacy_clk_override;
 
 	struct device		*dev;
@@ -676,6 +688,13 @@ static int wiz_regfield_init(struct wiz *wiz)
 		return PTR_ERR(wiz->typec_ln10_swap);
 	}
 
+	wiz->typec_ln23_swap = devm_regmap_field_alloc(dev, regmap,
+						       typec_ln23_swap);
+	if (IS_ERR(wiz->typec_ln23_swap)) {
+		dev_err(dev, "LN23_SWAP reg field init failed\n");
+		return PTR_ERR(wiz->typec_ln23_swap);
+	}
+
 	wiz->phy_en_refclk = devm_regmap_field_alloc(dev, regmap, phy_en_refclk);
 	if (IS_ERR(wiz->phy_en_refclk)) {
 		dev_err(dev, "PHY_EN_REFCLK reg field init failed\n");
@@ -1246,17 +1265,26 @@ static int wiz_phy_reset_deassert(struct reset_controller_dev *rcdev,
 			else
 				regmap_field_write(wiz->typec_ln10_swap, 0);
 		} else {
-			/* if no typec-dir gpio was specified and PHY type is
-			 * USB3 with master lane number is '0', set LN10 SWAP
-			 * bit to '1'
+			/* if no typec-dir gpio is specified and PHY type is USB3
+			 * with master lane number is '0' or '2', then set LN10 or
+			 * LN23 SWAP bit to '1' respectively.
 			 */
 			u32 num_lanes = wiz->num_lanes;
 			int i;
 
 			for (i = 0; i < num_lanes; i++) {
-				if (wiz->lane_phy_type[i] == PHY_TYPE_USB3)
-					if (wiz->master_lane_num[i] == 0)
+				if (wiz->lane_phy_type[i] == PHY_TYPE_USB3) {
+					switch (wiz->master_lane_num[i]) {
+					case LANE0:
 						regmap_field_write(wiz->typec_ln10_swap, 1);
+						break;
+					case LANE2:
+						regmap_field_write(wiz->typec_ln23_swap, 1);
+						break;
+					default:
+						break;
+					}
+				}
 			}
 		}
 	}
-- 
2.36.1