[PATCH 3/5] usb: typec: mux: ps883x: refactor DP altmode handling and support TYPEC_DP_STATE_F

[Jens Glathe via B4 Relay]

From: Jens Glathe <jens.glathe@xxxxxxxxxxxxxxxxxxxxxx>

Several docks, including the Lenovo 40B0 and SSK SC220, still send the
legacy TYPEC_DP_STATE_F mode request (deprecated since DisplayPort Alt
Mode spec version 1.0b). Treat it as USB3 + DP altmode (same as
TYPEC_DP_STATE_D) so that DP altmode works correctly, especially on
the 40B0 in Type-C fallback mode.

Extract the state handling into ps883x_apply_dp_altmode() (modelled
after qmp-combo-phy) for consistency.

Assisted-by: Grok(xAI):4.3
Signed-off-by: Jens Glathe <jens.glathe@xxxxxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/typec/mux/ps883x.c | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/typec/mux/ps883x.c b/drivers/usb/typec/mux/ps883x.c
index 3fa26ce01a9c9..3533d4f363286 100644
--- a/drivers/usb/typec/mux/ps883x.c
+++ b/drivers/usb/typec/mux/ps883x.c
@@ -188,6 +188,25 @@ static int ps883x_configure(struct ps883x_retimer *retimer, int cfg0,
 	return 0;
 }
 
+static void ps883x_apply_dp_altmode(int *cfg0, int *cfg1, int dp_state)
+{
+	*cfg1 |= CONN_STATUS_1_DP_CONNECTED | CONN_STATUS_1_DP_HPD_LEVEL;
+
+	switch (dp_state) {
+	case TYPEC_DP_STATE_D:
+	case TYPEC_DP_STATE_F:
+		*cfg0 |= CONN_STATUS_0_USB_3_1_CONNECTED;
+		fallthrough;
+	case TYPEC_DP_STATE_C:
+	case TYPEC_DP_STATE_E:
+		*cfg1 |= CONN_STATUS_1_DP_SINK_REQUESTED |
+			 CONN_STATUS_1_DP_PIN_ASSIGNMENT_C_D;
+		break;
+	default:
+		break;
+	}
+}
+
 static int ps883x_set(struct ps883x_retimer *retimer, struct typec_retimer_state *state)
 {
 	struct typec_thunderbolt_data *tb_data;
@@ -203,24 +222,10 @@ static int ps883x_set(struct ps883x_retimer *retimer, struct typec_retimer_state
 	if (state->alt) {
 		switch (state->alt->svid) {
 		case USB_TYPEC_DP_SID:
-			cfg1 |= CONN_STATUS_1_DP_CONNECTED |
-				CONN_STATUS_1_DP_HPD_LEVEL;
-
-			switch (state->mode)  {
-			case TYPEC_DP_STATE_D:
-				cfg0 |= CONN_STATUS_0_USB_3_1_CONNECTED;
-				fallthrough;
-			case TYPEC_DP_STATE_C:
-				cfg1 |= CONN_STATUS_1_DP_SINK_REQUESTED |
-					CONN_STATUS_1_DP_PIN_ASSIGNMENT_C_D;
-				break;
-			default: /* MODE_E */
-				break;
-			}
+			ps883x_apply_dp_altmode(&cfg0, &cfg1, state->mode);
 			break;
 		case USB_TYPEC_TBT_SID:
 			tb_data = state->data;
-
 			/* Unconditional */
 			cfg2 |= CONN_STATUS_2_TBT_CONNECTED;
 

-- 
2.53.0