usb: dwc2: Fix incorrect ULPI_UTMI_SEL bit setting

The ULPI_UTMI_SEL bit in the DWC2 driver was set incorrectly. According
to the datasheet [1], this bit should be set to 0 for UTMI interface and 1
for ULPI interface. The existing code had this logic reversed,
causing the interface selection to be incorrect.

This commit corrects the ULPI_UTMI_SEL bit setting to match the
datasheet's description. Referencing the kernel's code [2] also confirms
this fix.

[1] https://rockchip.fr/RK312X%20TRM/chapter-26-usb-otg-2-0.pdf#page=30
[2] https://github.com/torvalds/linux/blob/v6.13-rc3/drivers/usb/dwc2/core.c#L1106

Reviewed-by: Marek Vasut <marex@denx.de>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Link: https://lore.kernel.org/r/20250110-dwc2-dev-v4-2-987f4fd6f8b2@pigmoral.tech
Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index b6c8b3d5a6bdf375f1adeb106d4832d92307f0db..609de18faa3abc5f4ecb0c23cf3590966bad7992 100644 (file)
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -402,20 +402,22 @@ static void dwc_otg_core_init(struct udevice *dev)
         * soft reset so only program the first time. Do a soft reset
         * immediately after setting phyif.
         */
-       usbcfg &= ~(DWC2_GUSBCFG_ULPI_UTMI_SEL | DWC2_GUSBCFG_PHYIF);
-       usbcfg |= DWC2_PHY_TYPE << DWC2_GUSBCFG_ULPI_UTMI_SEL_OFFSET;
-
-       if (usbcfg & DWC2_GUSBCFG_ULPI_UTMI_SEL) {      /* ULPI interface */
+#if (DWC2_PHY_TYPE == DWC2_PHY_TYPE_ULPI)
+       usbcfg |= DWC2_GUSBCFG_ULPI_UTMI_SEL;
+       usbcfg &= ~DWC2_GUSBCFG_PHYIF;
 #ifdef DWC2_PHY_ULPI_DDR
-               usbcfg |= DWC2_GUSBCFG_DDRSEL;
+       usbcfg |= DWC2_GUSBCFG_DDRSEL;
 #else
-               usbcfg &= ~DWC2_GUSBCFG_DDRSEL;
-#endif
-       } else {        /* UTMI+ interface */
+       usbcfg &= ~DWC2_GUSBCFG_DDRSEL;
+#endif /* DWC2_PHY_ULPI_DDR */
+#elif (DWC2_PHY_TYPE == DWC2_PHY_TYPE_UTMI)
+       usbcfg &= ~DWC2_GUSBCFG_ULPI_UTMI_SEL;
 #if (DWC2_UTMI_WIDTH == 16)
-               usbcfg |= DWC2_GUSBCFG_PHYIF;
-#endif
-       }
+       usbcfg |= DWC2_GUSBCFG_PHYIF;
+#else
+       usbcfg &= ~DWC2_GUSBCFG_PHYIF;
+#endif /* DWC2_UTMI_WIDTH */
+#endif /* DWC2_PHY_TYPE */
 
        writel(usbcfg, &regs->global_regs.gusbcfg);