[PATCH v2 5/9] usb: xhci-pci: Add support for reset controllers
From: Nicolas Saenz Julienne
Date: Tue Jun 09 2020 - 13:51:07 EST
Some atypical users of xhci-pci 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@xxxxxxx>
---
Changes since v1:
- Use proper reset API
- Make code simpler
drivers/usb/host/xhci-pci.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index ef513c2fb843..6e96affa4ceb 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -12,6 +12,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/acpi.h>
+#include <linux/reset.h>
#include "xhci.h"
#include "xhci-trace.h"
@@ -339,6 +340,7 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
struct xhci_hcd *xhci;
struct usb_hcd *hcd;
struct xhci_driver_data *driver_data;
+ struct reset_control *reset;
driver_data = (struct xhci_driver_data *)id->driver_data;
if (driver_data && driver_data->quirks & XHCI_RENESAS_FW_QUIRK) {
@@ -347,6 +349,11 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
return retval;
}
+ reset = devm_reset_control_get_optional_exclusive(&dev->bus->dev, NULL);
+ if (IS_ERR(reset))
+ return PTR_ERR(reset);
+ reset_control_reset(reset);
+
/* Prevent runtime suspending between USB-2 and USB-3 initialization */
pm_runtime_get_noresume(&dev->dev);
--
2.26.2