BACKPORT: usb: dwc3: core: Set force_gen1 bit for all applicable SuperSpeed ports

Currently if the maximum-speed is set to Super Speed for a 3.1 Gen2
capable controller, the FORCE_GEN1 bit of LLUCTL register is set only
for one SuperSpeed port (or the first port) present. Modify the logic
to set the FORCE_GEN1 bit for all ports if speed is being limited to
Gen-1.

Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20241112182018.199392-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit ce25e2a8d82de7f8bcbedd18973e5b8030749d45
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master)

Bug: 379220296
Change-Id: I4b2b12ea343aa1f8a97c812815b9d39d8b2b836f
[quic_kuruva: Minor correction, 'num_usb3_ports' is part of the
DWC structure in upstream. However, it has been acknowledged that
it has moved to dwc3_vendor to avoid an ABI break,
replacing 'dwc' with 'vdwc' in the change.]
Signed-off-by: Rajashekar kuruva <quic_kuruva@quicinc.com>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a8ea07e..12089ba 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1425,9 +1425,13 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	if (hw_mode != DWC3_GHWPARAMS0_MODE_GADGET &&
 	    (DWC3_IP_IS(DWC31)) &&
 	    dwc->maximum_speed == USB_SPEED_SUPER) {
-		reg = dwc3_readl(dwc->regs, DWC3_LLUCTL);
-		reg |= DWC3_LLUCTL_FORCE_GEN1;
-		dwc3_writel(dwc->regs, DWC3_LLUCTL, reg);
+		int i;
+
+		for (i = 0; i < vdwc->num_usb3_ports; i++) {
+			reg = dwc3_readl(dwc->regs, DWC3_LLUCTL(i));
+			reg |= DWC3_LLUCTL_FORCE_GEN1;
+			dwc3_writel(dwc->regs, DWC3_LLUCTL(i), reg);
+		}
 	}
 
 	return 0;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index ecff4c9..c77bb7f 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -180,7 +180,7 @@
 #define DWC3_OEVTEN		0xcc0C
 #define DWC3_OSTS		0xcc10
 
-#define DWC3_LLUCTL		0xd024
+#define DWC3_LLUCTL(n)		(0xd024 + ((n) * 0x80))
 
 /* Bit fields */