[PATCH] usb: dwc3: Initialize Xilinx glue registers

Sean Anderson
2026-01-06T22:17:43Z

These registers may have been initialized by SPL/FSBL, but program them
in case they have not. If they are left at their default values, the
controller will never exit reset.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>

---

drivers/usb/dwc3/dwc3-generic.c | 32 ++++++++++++++++++++++++++------
drivers/usb/dwc3/dwc3-generic.h | 2 ++
2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index c09014aec60..ce896db9532 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -501,6 +501,27 @@ struct dwc3_glue_ops rk_ops = {
.glue_get_ctrl_dev = dwc3_rk_glue_get_ctrl_dev,
};

+void dwc3_xlnx_glue_configure(struct udevice *dev, int index,
+ enum usb_dr_mode mode)
+{
+/* USB glue registers */
+#define USB3_FPD_PIPE_CLK 0x7c
+#define USB3_FPD_POWER_PRSNT 0x80
+ struct dwc3_glue_data *glue = dev_get_plat(dev);
+ void *base = map_physmem(glue->regs, 0x10000, MAP_NOCACHE);
+
+ if (generic_phy_valid(&glue->phy)) {
+ writel(0, base + USB3_FPD_PIPE_CLK);
+ writel(1, base + USB3_FPD_POWER_PRSNT);
+ } else {
+ writel(1, base + USB3_FPD_PIPE_CLK);
+ }
+}
+
+struct dwc3_glue_ops xlnx_ops = {
+ .glue_configure = dwc3_xlnx_glue_configure,
+};
+
static int dwc3_glue_bind_common(struct udevice *parent, ofnode node)
{
const char *name = ofnode_get_name(node);
@@ -621,11 +642,10 @@ int dwc3_glue_probe(struct udevice *dev)
struct udevice *child = NULL;
int index = 0;
int ret;
- struct phy phy;

- ret = generic_phy_get_by_name(dev, "usb3-phy", &phy);
+ ret = generic_phy_get_by_name(dev, "usb3-phy", &glue->phy);
if (!ret) {
- ret = generic_phy_init(&phy);
+ ret = generic_phy_init(&glue->phy);
if (ret)
return ret;
} else if (ret != -ENOENT && ret != -ENODATA) {
@@ -643,8 +663,8 @@ int dwc3_glue_probe(struct udevice *dev)
if (ret)
return ret;

- if (generic_phy_valid(&phy)) {
- ret = generic_phy_power_on(&phy);
+ if (generic_phy_valid(&glue->phy)) {
+ ret = generic_phy_power_on(&glue->phy);
if (ret)
return ret;
}
@@ -690,7 +710,7 @@ int dwc3_glue_remove(struct udevice *dev)
}

static const struct udevice_id dwc3_glue_ids[] = {
- { .compatible = "xlnx,zynqmp-dwc3" },
+ { .compatible = "xlnx,zynqmp-dwc3", .data = (ulong)&xlnx_ops },
{ .compatible = "xlnx,versal-dwc3" },
{ .compatible = "ti,keystone-dwc3"},
{ .compatible = "ti,dwc3", .data = (ulong)&ti_ops },
diff --git a/drivers/usb/dwc3/dwc3-generic.h b/drivers/usb/dwc3/dwc3-generic.h
index 40902c8923f..13f6391cae8 100644
--- a/drivers/usb/dwc3/dwc3-generic.h
+++ b/drivers/usb/dwc3/dwc3-generic.h
@@ -10,12 +10,14 @@
#define __DRIVERS_USB_DWC3_GENERIC_H

#include <clk.h>
+#include <generic-phy.h>
#include <reset.h>
#include <dwc3-uboot.h>

struct dwc3_glue_data {
struct clk_bulk clks;
struct reset_ctl_bulk resets;
+ struct phy phy;
fdt_addr_t regs;
fdt_size_t size;
};
--
2.35.1.1320.gc452695387.dirty

base-commit: beab3fe49e1e9209dd32fe2791e7ac706038460f
branch: dwc3_xlnx_glue