usb: dwc3: core: add external vBus supply support for ulpi phy

Some ULPI USB PHY does not support internal VBUS supply, to drive the CPEN
pin, which requires the configuration of the ULPI DRVVBUSEXTERNAL bit of
OTG_CTRL register.

Added 'snps,ulpi-ext-vbus-drv' a DT property to configure the USB2 PHY to
drive VBUS with an external supply, by setting the USB2 PHY ULPIEXTVBUSDRV
bit[:17] of the GUSB2PHYCFG register to drive VBUS with an external supply.
Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
Link: https://lore.kernel.org/r/20230215093146.5812-3-piyush.mehta@amd.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/core.c

@@ -800,6 +800,16 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
 	if (dwc->dis_u2_freeclk_exists_quirk || dwc->gfladj_refclk_lpm_sel)
 		reg &= ~DWC3_GUSB2PHYCFG_U2_FREECLK_EXISTS;
 
+	/*
+	 * Some ULPI USB PHY does not support internal VBUS supply, to drive
+	 * the CPEN pin requires the configuration of the ULPI DRVVBUSEXTERNAL
+	 * bit of OTG_CTRL register. Controller configures the USB2 PHY
+	 * ULPIEXTVBUSDRV bit[17] of the GUSB2PHYCFG register to drive vBus
+	 * with an external supply.
+	 */
+	if (dwc->ulpi_ext_vbus_drv)
+		reg |= DWC3_GUSB2PHYCFG_ULPIEXTVBUSDRV;
+
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
 
 	return 0;
@@ -1553,6 +1563,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,dis-tx-ipgap-linecheck-quirk");
 	dwc->resume_hs_terminations = device_property_read_bool(dev,
 				"snps,resume-hs-terminations");
+	dwc->ulpi_ext_vbus_drv = device_property_read_bool(dev,
+				"snps,ulpi-ext-vbus-drv");
 	dwc->parkmode_disable_ss_quirk = device_property_read_bool(dev,
 				"snps,parkmode-disable-ss-quirk");
 	dwc->gfladj_refclk_lpm_sel = device_property_read_bool(dev,

drivers/usb/dwc3/core.h

@@ -280,6 +280,7 @@
 /* Global USB2 PHY Configuration Register */
 #define DWC3_GUSB2PHYCFG_PHYSOFTRST	BIT(31)
 #define DWC3_GUSB2PHYCFG_U2_FREECLK_EXISTS	BIT(30)
+#define DWC3_GUSB2PHYCFG_ULPIEXTVBUSDRV	BIT(17)
 #define DWC3_GUSB2PHYCFG_SUSPHY		BIT(6)
 #define DWC3_GUSB2PHYCFG_ULPI_UTMI	BIT(4)
 #define DWC3_GUSB2PHYCFG_ENBLSLPM	BIT(8)
@@ -1100,6 +1101,8 @@ struct dwc3_scratchpad_array {
  *			check during HS transmit.
  * @resume-hs-terminations: Set if we enable quirk for fixing improper crc
  *			generation after resume from suspend.
+ * @ulpi_ext_vbus_drv: Set to confiure the upli chip to drives CPEN pin
+ *			VBUS with an external supply.
  * @parkmode_disable_ss_quirk: set if we need to disable all SuperSpeed
  *			instances in park mode.
  * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
@@ -1317,6 +1320,7 @@ struct dwc3 {
 	unsigned		dis_del_phy_power_chg_quirk:1;
 	unsigned		dis_tx_ipgap_linecheck_quirk:1;
 	unsigned		resume_hs_terminations:1;
+	unsigned		ulpi_ext_vbus_drv:1;
 	unsigned		parkmode_disable_ss_quirk:1;
 	unsigned		gfladj_refclk_lpm_sel:1;