[PATCH] usb: dwc3: Initialize Xilinx glue registers

[Kumar, Love]

Hi,

On 1/22/2026 6:55 PM, Michal Simek wrote:
> +Love
> 
> 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 at linux.dev>

Verified it on AMD platforms and not seeing any issue.

Tested-by: Love Kumar <love.kumar at amd.com>

Regards,
Love Kumar

>>>>>
>>>>> ---
>>>>>
>>>>>    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.
>>
>> --Sean
>>
>> [1] https://lore.kernel.org/linux-usb/8f0e04a5-49df-4fe3-9c76-9a1c0bd822a0@linux.dev/
>> [2] https://lore.kernel.org/linux-usb/be8a566a-163f-4d20-b712-67de6f63a6b5@linux.dev/
> 
> Love: Can you please test this patch and provide your tested-by flag if it is working.
> 
> Thanks,
> Michal
>