Re: [PATCH] usb: dwc2: update reset method for host and device mode

[Marek Vasut]

On 4/22/24 7:31 AM, Kongyang Liu wrote:

[...]
@@ -167,9 +168,20 @@ static void dwc_otg_core_reset(struct udevice *dev,
               dev_info(dev, "%s: Timeout!\n", __func__);

       /* Core Soft Reset */
+     snpsid = readl(&regs->gsnpsid);
       writel(DWC2_GRSTCTL_CSFTRST, &regs->grstctl);
-     ret = wait_for_bit_le32(&regs->grstctl, DWC2_GRSTCTL_CSFTRST,
-                             false, 1000, false);
+     if ((snpsid & DWC2_SNPSID_VER_MASK) < (DWC2_SNPSID_DEVID_VER_420a & 
DWC2_SNPSID_VER_MASK)) {
+             ret = wait_for_bit_le32(&regs->grstctl, DWC2_GRSTCTL_CSFTRST,
+                                     false, 1000, false);
+     } else {
+             ret = wait_for_bit_le32(&regs->grstctl, DWC2_GRSTCTL_GSFTRST_DONE,
+                                     true, 1000, false);
+             greset = readl(&regs->grstctl);
+             greset &= ~DWC2_GRSTCTL_CSFTRST;
+             greset |= DWC2_GRSTCTL_GSFTRST_DONE;
+             writel(greset, &regs->grstctl);

Same comments as above.

Maybe this should be pulled into dedicated function to avoid duplication?


For U-Boot, the dwc2 USB driver is split into two modules: host and gadget.
Each has its own register definitions and definitions for register bits,
which makes it difficult to extract a single function. Moreover, deciding
where to place this function is also an issue.

There is drivers/usb/common/ for such code. The register macros can 
probably be unified into a single header too.