Re: [PATCH v3 2/2] usb: dwc3: Add support for usb3-phy PHY configuration

[Michal Simek]

Hi Jan,

On 4/25/22 11:47, Jan Kiszka wrote:
On 09.03.22 10:05, Michal Simek wrote:
When usb3-phy label is found, PHY driver is called and serdes line is
initialized. This is preparation for serdes/psgtr driver to configure GT
lines based on description in DT.
Signed-off-by: Michal Simek <michal.si...@xilinx.com>
---

Changes in v3:
- Add cover letter

Changes in v2:
- Add missing header

  drivers/usb/dwc3/dwc3-generic.c | 18 ++++++++++++++++++
  1 file changed, 18 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 01bd0ca190e3..2c5205df62cd 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -14,6 +14,7 @@
  #include <dm/device-internal.h>
  #include <dm/lists.h>
  #include <dwc3-uboot.h>
+#include <generic-phy.h>
  #include <linux/bitops.h>
  #include <linux/delay.h>
  #include <linux/usb/ch9.h>
@@ -409,6 +410,17 @@ static 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);
+       if (!ret) {
+               ret = generic_phy_init(&phy);
+               if (ret)
+                       return ret;
+       } else if (ret != -ENOENT) {
+               debug("could not get phy (err %d)\n", ret);
+               return ret;
+       }
  
  	glue->regs = dev_read_addr(dev);
  
@@ -420,6 +432,12 @@ static int dwc3_glue_probe(struct udevice *dev)
        if (ret)
                return ret;
  
+	if (phy.dev) {
+               ret = generic_phy_power_on(&phy);
+               if (ret)
+                       return ret;
+       }
+
        ret = device_find_first_child(dev, &child);
        if (ret)
                return ret;

Breaks USB on the iot2050-pg1 (am65x) - this one has NO usb3-phy:

...
starting USB...
Bus usb@10000: probe failed, error -61
Bus usb@10000: probe failed, error -61
No working controllers found
USB is stopped. Please issue 'usb start' first.
starting USB...
Bus usb@10000: probe failed, error -61
Bus usb@10000: probe failed, error -61
No working controllers found
USB is stopped. Please issue 'usb start' first.
starting USB...
Bus usb@10000: probe failed, error -61
Bus usb@10000: probe failed, error -61
No working controllers found
USB is stopped. Please issue 'usb start' first.

Is there anything that boards need to consider now?

-61 is ENODATA. I have looked at DT and there is no usb3-phy property. That's 
why generic_phy_get_by_name() can't return 0. Does it return -ENOENT?

Maybe it returns ENODATA and it should be also handled in else part.

Can you please enable debug and see?

Thanks,
Michal