PCI: add Intel USB specific reset method

Handle device specific reset requirements (i.e. vendor reg for reset
along with appropriate timeout).

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 86c9177a6c6c..cf96776d4bbf 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2642,7 +2642,31 @@ fs_initcall_sync(pci_apply_final_quirks);
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */
+static int reset_intel_generic_dev(struct pci_dev *dev, int probe)
+{
+        int pos;
+
+        /* only implement PCI_CLASS_SERIAL_USB at present */
+        if (dev->class == PCI_CLASS_SERIAL_USB) {
+                pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
+                if (!pos)
+                        return -ENOTTY;
+
+                if (probe)
+                        return 0;
+
+                pci_write_config_byte(dev, pos + 0x4, 1);
+                msleep(100);
+
+                return 0;
+        } else {
+                return -ENOTTY;
+        }
+}
+
 struct pci_dev_reset_methods pci_dev_reset_methods[] = {
+        { PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
+                reset_intel_generic_dev },
         { 0 }
 };
 #else