usb: xhci: Add reset controller support
Some atypical users of xhci might need to manually reset their xHCI
controller before starting the HCD setup. Check if a reset controller
device is available to the PCI bus and trigger a reset.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
[mb: squash fix to only build xhci_reset_hw() if CONFIG_DM_BUS]
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ebd2954..f635bb3 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -190,6 +190,37 @@
return ret;
}
+#if CONFIG_IS_ENABLED(DM_USB)
+/**
+ * Resets XHCI Hardware
+ *
+ * @param ctrl pointer to host controller
+ * @return 0 if OK, or a negative error code.
+ */
+static int xhci_reset_hw(struct xhci_ctrl *ctrl)
+{
+ int ret;
+
+ ret = reset_get_by_index(ctrl->dev, 0, &ctrl->reset);
+ if (ret && ret != -ENOENT && ret != -ENOTSUPP) {
+ dev_err(ctrl->dev, "failed to get reset\n");
+ return ret;
+ }
+
+ if (reset_valid(&ctrl->reset)) {
+ ret = reset_assert(&ctrl->reset);
+ if (ret)
+ return ret;
+
+ ret = reset_deassert(&ctrl->reset);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
/**
* Resets the XHCI Controller
*
@@ -1508,6 +1539,10 @@
ctrl->dev = dev;
+ ret = xhci_reset_hw(ctrl);
+ if (ret)
+ goto err;
+
/*
* XHCI needs to issue a Address device command to setup
* proper device context structures, before it can interact