usb: dwc2: add "u-boot,force-vbus-detection" for stm32

On some board, the ID pin is not connected so the B session must be
overridden with "u-boot,force_b_session_valid" but the VBus sensing
must continue to be handle.

To managed it, this patch adds a new DT field
"u-boot,force-vbus-detection" to use with "u-boot,force_b_session_valid"
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

drivers/usb/gadget/dwc2_udc_otg.c

@@ -1014,6 +1014,9 @@ static int dwc2_udc_otg_ofdata_to_platdata(struct udevice *dev)
 	platdata->force_b_session_valid =
 		dev_read_bool(dev, "u-boot,force-b-session-valid");
 
+	platdata->force_vbus_detection =
+		dev_read_bool(dev, "u-boot,force-vbus-detection");
+
 	/* force platdata according compatible */
 	drvdata = dev_get_driver_data(dev);
 	if (drvdata) {
@@ -1106,31 +1109,45 @@ static int dwc2_udc_otg_probe(struct udevice *dev)
 	if (ret)
 		return ret;
 
-	if (CONFIG_IS_ENABLED(DM_REGULATOR) &&
-	    platdata->activate_stm_id_vb_detection &&
-	    !platdata->force_b_session_valid) {
-		ret = device_get_supply_regulator(dev, "usb33d-supply",
-						  &priv->usb33d_supply);
-		if (ret) {
-			dev_err(dev, "can't get voltage level detector supply\n");
-			return ret;
+	if (platdata->activate_stm_id_vb_detection) {
+		if (CONFIG_IS_ENABLED(DM_REGULATOR) &&
+		    (!platdata->force_b_session_valid ||
+		     platdata->force_vbus_detection)) {
+			ret = device_get_supply_regulator(dev, "usb33d-supply",
+							  &priv->usb33d_supply);
+			if (ret) {
+				dev_err(dev, "can't get voltage level detector supply\n");
+				return ret;
+			}
+			ret = regulator_set_enable(priv->usb33d_supply, true);
+			if (ret) {
+				dev_err(dev, "can't enable voltage level detector supply\n");
+				return ret;
+			}
 		}
-		ret = regulator_set_enable(priv->usb33d_supply, true);
-		if (ret) {
-			dev_err(dev, "can't enable voltage level detector supply\n");
-			return ret;
+
+		if (platdata->force_b_session_valid &&
+		    !platdata->force_vbus_detection) {
+			/* Override VBUS detection: enable then value*/
+			setbits_le32(&usbotg_reg->gotgctl, VB_VALOEN);
+			setbits_le32(&usbotg_reg->gotgctl, VB_VALOVAL);
+		} else {
+			/* Enable VBUS sensing */
+			setbits_le32(&usbotg_reg->ggpio,
+				     GGPIO_STM32_OTG_GCCFG_VBDEN);
+		}
+		if (platdata->force_b_session_valid) {
+			/* Override B session bits: enable then value */
+			setbits_le32(&usbotg_reg->gotgctl, A_VALOEN | B_VALOEN);
+			setbits_le32(&usbotg_reg->gotgctl,
+				     A_VALOVAL | B_VALOVAL);
+		} else {
+			/* Enable ID detection */
+			setbits_le32(&usbotg_reg->ggpio,
+				     GGPIO_STM32_OTG_GCCFG_IDEN);
 		}
-		/* Enable vbus sensing */
-		setbits_le32(&usbotg_reg->ggpio,
-			     GGPIO_STM32_OTG_GCCFG_VBDEN |
-			     GGPIO_STM32_OTG_GCCFG_IDEN);
 	}
 
-	if (platdata->force_b_session_valid)
-		/* Override B session bits : value and enable */
-		setbits_le32(&usbotg_reg->gotgctl,
-			     A_VALOEN | A_VALOVAL | B_VALOEN | B_VALOVAL);
-
 	ret = dwc2_udc_probe(platdata);
 	if (ret)
 		return ret;

drivers/usb/gadget/dwc2_udc_otg_regs.h

@@ -94,6 +94,8 @@ struct dwc2_usbotg_reg {
 #define B_VALOEN			BIT(6)
 #define A_VALOVAL			BIT(5)
 #define A_VALOEN			BIT(4)
+#define VB_VALOVAL			BIT(3)
+#define VB_VALOEN			BIT(2)
 
 /* DWC2_UDC_OTG_GOTINT */
 #define GOTGINT_SES_END_DET		(1<<2)

include/usb/dwc2_udc.h

@@ -28,6 +28,7 @@ struct dwc2_plat_otg_data {
 	unsigned int	tx_fifo_sz_array[DWC2_MAX_HW_ENDPOINTS];
 	unsigned char   tx_fifo_sz_nb;
 	bool		force_b_session_valid;
+	bool		force_vbus_detection;
 	bool		activate_stm_id_vb_detection;
 };