Re: [PATCH] usb: dwc3: Initialize Xilinx glue registers

Michal Simek
2026-01-29T10:14:11Z

On 1/16/26 17:14, Sean Anderson wrote:
> On 1/16/26 09:07, Marek Vasut wrote:
>> On 1/16/26 9:19 AM, Michal Simek wrote:
>>>
>>>
>>> On 1/6/26 23:17, Sean Anderson wrote:
>>>> 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;
>>>>   };
>>>
>>> I will let Marek to handle this. From my perspective we should take Jerome's patchset to update usb stack and then add this on the top.
>> Since this fixes a real bug and is isolated to xilinx platform, it would be good if xilinx at least provided feedback on this patch.
>>
>> +CC Ilias
>
> It's not a bug fix (hence no fixes tag). See [1,2] for details.
>

Please hold on this patch. I got information that we see some issues on one
board when this patch is applied.
We will get back to you.

Thanks,
Michal