[PATCH v2 5/7] usb: dwc3: add xhci-reset-on-resume property for power-loss resume

[Faisal Hassan]

On platforms where the USB controller loses power during system
suspend, like SA8255P, resume triggers a Host Controller Error
requiring full reinitialization.

The xhci driver supports XHCI_RESET_ON_RESUME to handle this,
but dwc3 previously lacked platform-specific quirk configuration.
Add a device property "xhci-reset-on-resume" that enables this
quirk for controllers needing complete reinitialization after
power loss during suspend.

Let dwc3 manage the quirk for the usb controller using
software properties.

Co-developed-by: Sriram Dash <sriram.dash@xxxxxxxxxxxxxxxx>
Signed-off-by: Sriram Dash <sriram.dash@xxxxxxxxxxxxxxxx>
Signed-off-by: Faisal Hassan <faisal.hassan@xxxxxxxxxxxxxxxx>
---
 drivers/usb/dwc3/core.c | 4 ++++
 drivers/usb/dwc3/core.h | 5 +++++
 drivers/usb/dwc3/host.c | 5 ++++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index fd5c2cd36c59..eb6ffd5148a7 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1712,6 +1712,10 @@ static void dwc3_get_software_properties(struct dwc3 *dwc,
 					       &gsbuscfg0_reqinfo);
 		if (!ret)
 			dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
+
+		if (!dwc->xhci_reset_on_resume &&
+		    device_property_read_bool(tmpdev, "xhci-reset-on-resume"))
+			dwc->xhci_reset_on_resume = true;
 	}
 }
 
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 608daeb7ef10..0ff23eb217bc 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1172,6 +1172,10 @@ struct dwc3_glue_ops {
  * @suspended: set to track suspend event due to U3/L2.
  * @susphy_state: state of DWC3_GUSB2PHYCFG_SUSPHY + DWC3_GUSB3PIPECTL_SUSPHY
  *		  before PM suspend.
+ * @xhci_reset_on_resume: Enable XHCI_RESET_ON_RESUME quirk for the xHCI
+ *			  host controller. Set to true for platforms where
+ *			  the USB controller loses power during system suspend,
+ *			  requiring complete reinitialization on resume.
  * @imod_interval: set the interrupt moderation interval in 250ns
  *			increments or 0 to disable.
  * @max_cfg_eps: current max number of IN eps used across all USB configs.
@@ -1420,6 +1424,7 @@ struct dwc3 {
 	unsigned		wakeup_configured:1;
 	unsigned		suspended:1;
 	unsigned		susphy_state:1;
+	unsigned		xhci_reset_on_resume:1;
 
 	u16			imod_interval;
 
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 96b588bd08cd..2170fcafc889 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -129,7 +129,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)
 
 int dwc3_host_init(struct dwc3 *dwc)
 {
-	struct property_entry	props[6];
+	struct property_entry	props[7];
 	struct platform_device	*xhci;
 	int			ret, irq;
 	int			prop_idx = 0;
@@ -173,6 +173,9 @@ int dwc3_host_init(struct dwc3 *dwc)
 	if (dwc->usb2_lpm_disable)
 		props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable");
 
+	if (dwc->xhci_reset_on_resume)
+		props[prop_idx++] = PROPERTY_ENTRY_BOOL("xhci-reset-on-resume-quirk");
+
 	/**
 	 * WORKAROUND: dwc3 revisions <=3.00a have a limitation
 	 * where Port Disable command doesn't work.
-- 
2.34.1