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

Marek Vasut
2026-01-16T16:11:14Z

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