USB: UHCI: Support non-PCI host controllers

[~andy/linux] / drivers / usb / host / uhci-hcd.c

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 5176c537b95aaefd8c2f6960d67c3357d3153140..cd482fcc05dac787382f873274e147f3b888c21c 100644 (file)
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -167,6 +167,79 @@ static void check_and_reset_hc(struct uhci_hcd *uhci)
                finish_reset(uhci);
 }
 
+#if defined(CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC)
+/*
+ * The two functions below are generic reset functions that are used on systems
+ * that do not have keyboard and mouse legacy support. We assume that we are
+ * running on such a system if CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC is defined.
+ */
+
+/*
+ * Make sure the controller is completely inactive, unable to
+ * generate interrupts or do DMA.
+ */
+static void uhci_generic_reset_hc(struct uhci_hcd *uhci)
+{
+       /* Reset the HC - this will force us to get a
+        * new notification of any already connected
+        * ports due to the virtual disconnect that it
+        * implies.
+        */
+       uhci_writew(uhci, USBCMD_HCRESET, USBCMD);
+       mb();
+       udelay(5);
+       if (uhci_readw(uhci, USBCMD) & USBCMD_HCRESET)
+               dev_warn(uhci_dev(uhci), "HCRESET not completed yet!\n");
+
+       /* Just to be safe, disable interrupt requests and
+        * make sure the controller is stopped.
+        */
+       uhci_writew(uhci, 0, USBINTR);
+       uhci_writew(uhci, 0, USBCMD);
+}
+
+/*
+ * Initialize a controller that was newly discovered or has just been
+ * resumed.  In either case we can't be sure of its previous state.
+ *
+ * Returns: 1 if the controller was reset, 0 otherwise.
+ */
+static int uhci_generic_check_and_reset_hc(struct uhci_hcd *uhci)
+{
+       unsigned int cmd, intr;
+
+       /*
+        * When restarting a suspended controller, we expect all the
+        * settings to be the same as we left them:
+        *
+        *      Controller is stopped and configured with EGSM set;
+        *      No interrupts enabled except possibly Resume Detect.
+        *
+        * If any of these conditions are violated we do a complete reset.
+        */
+
+       cmd = uhci_readw(uhci, USBCMD);
+       if ((cmd & USBCMD_RS) || !(cmd & USBCMD_CF) || !(cmd & USBCMD_EGSM)) {
+               dev_dbg(uhci_dev(uhci), "%s: cmd = 0x%04x\n",
+                               __func__, cmd);
+               goto reset_needed;
+       }
+
+       intr = uhci_readw(uhci, USBINTR);
+       if (intr & (~USBINTR_RESUME)) {
+               dev_dbg(uhci_dev(uhci), "%s: intr = 0x%04x\n",
+                               __func__, intr);
+               goto reset_needed;
+       }
+       return 0;
+
+reset_needed:
+       dev_dbg(uhci_dev(uhci), "Performing full reset\n");
+       uhci_generic_reset_hc(uhci);
+       return 1;
+}
+#endif /* CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC */
+
 /*
  * Store the basic register settings needed by the controller.
  */