[PATCH v6 3/8] usb: dwc3: core: Skip setting event buffers for host only controllers

[Krishna Kurapati]

On some SoC's like SA8295P where the tertiary controller is host-only
capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
Trying to setup them up during core_init leads to a crash.

For DRD/Peripheral supported controllers, event buffer setup is done
again in gadget_pullup. Skip setup or cleanup of event buffers if
controller is host-only capable.

Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
---
Link to v5: https://lore.kernel.org/all/20230310163420.7582-4-quic_kriskura@xxxxxxxxxxx/

 drivers/usb/dwc3/core.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 567ae79389a1..2964bcaa0a27 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -839,7 +839,11 @@ static void dwc3_clk_disable(struct dwc3 *dwc)
 
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
-	dwc3_event_buffers_cleanup(dwc);
+	unsigned int	hw_mode;
+
+	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
+		dwc3_event_buffers_cleanup(dwc);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 1);
 	usb_phy_set_suspend(dwc->usb3_phy, 1);
@@ -1176,10 +1180,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	if (ret < 0)
 		goto err3;
 
-	ret = dwc3_event_buffers_setup(dwc);
-	if (ret) {
-		dev_err(dwc->dev, "failed to setup event buffers\n");
-		goto err4;
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST) {
+		ret = dwc3_event_buffers_setup(dwc);
+		if (ret) {
+			dev_err(dwc->dev, "failed to setup event buffers\n");
+			goto err4;
+		}
 	}
 
 	/*
@@ -2002,7 +2008,9 @@ static int dwc3_probe(struct platform_device *pdev)
 
 err5:
 	dwc3_debugfs_exit(dwc);
-	dwc3_event_buffers_cleanup(dwc);
+
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
+		dwc3_event_buffers_cleanup(dwc);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 1);
 	usb_phy_set_suspend(dwc->usb3_phy, 1);
-- 
2.40.0