5 files changed, 112 insertions, 3 deletions

diff --git a/arch/powerpc/boot/dts/sequoia.dts b/arch/powerpc/boot/dts/sequoia.dts
index 3b295e8df53f..43cc68bd3192 100644
--- a/arch/powerpc/boot/dts/sequoia.dts
+++ b/arch/powerpc/boot/dts/sequoia.dts
@@ -134,7 +134,7 @@
                 };
 
                 USB1: usb@e0000400 {
-                        compatible = "ohci-be";
+                        compatible = "ibm,usb-ohci-440epx", "ohci-be";
                         reg = <0x00000000 0xe0000400 0x00000060>;
                         interrupt-parent = <&UIC0>;
                         interrupts = <0x15 0x8>;
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 38650707dfe0..97a53a48a3d8 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -434,8 +434,15 @@ static int check_reset_complete (
                 port_status &= ~PORT_RWC_BITS;
                 ehci_writel(ehci, port_status, status_reg);
 
-        } else
+                /* ensure 440EPX ohci controller state is operational */
+                if (ehci->has_amcc_usb23)
+                        set_ohci_hcfs(ehci, 1);
+        } else {
                 ehci_dbg (ehci, "port %d high speed\n", index + 1);
+                /* ensure 440EPx ohci controller state is suspended */
+                if (ehci->has_amcc_usb23)
+                        set_ohci_hcfs(ehci, 0);
+        }
 
         return port_status;
 }
diff --git a/drivers/usb/host/ehci-ppc-of.c b/drivers/usb/host/ehci-ppc-of.c
index b018deed2e8f..ef732b704f53 100644
--- a/drivers/usb/host/ehci-ppc-of.c
+++ b/drivers/usb/host/ehci-ppc-of.c
@@ -107,11 +107,13 @@ ehci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
 {
         struct device_node *dn = op->node;
         struct usb_hcd *hcd;
-        struct ehci_hcd *ehci;
+        struct ehci_hcd *ehci = NULL;
         struct resource res;
         int irq;
         int rv;
 
+        struct device_node *np;
+
         if (usb_disabled())
                 return -ENODEV;
 
@@ -149,6 +151,20 @@ ehci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
         }
 
         ehci = hcd_to_ehci(hcd);
+        np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
+        if (np != NULL) {
+                /* claim we really affected by usb23 erratum */
+                if (!of_address_to_resource(np, 0, &res))
+                        ehci->ohci_hcctrl_reg = ioremap(res.start +
+                                        OHCI_HCCTRL_OFFSET, OHCI_HCCTRL_LEN);
+                else
+                        pr_debug(__FILE__ ": no ohci offset in fdt\n");
+                if (!ehci->ohci_hcctrl_reg) {
+                        pr_debug(__FILE__ ": ioremap for ohci hcctrl failed\n");
+                } else {
+                        ehci->has_amcc_usb23 = 1;
+                }
+        }
 
         if (of_get_property(dn, "big-endian", NULL)) {
                 ehci->big_endian_mmio = 1;
@@ -181,6 +197,9 @@ err_ioremap:
         irq_dispose_mapping(irq);
 err_irq:
         release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+
+        if (ehci->has_amcc_usb23)
+                iounmap(ehci->ohci_hcctrl_reg);
 err_rmr:
         usb_put_hcd(hcd);
 
@@ -191,6 +210,11 @@ err_rmr:
 static int ehci_hcd_ppc_of_remove(struct of_device *op)
 {
         struct usb_hcd *hcd = dev_get_drvdata(&op->dev);
+        struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+        struct device_node *np;
+        struct resource res;
+
         dev_set_drvdata(&op->dev, NULL);
 
         dev_dbg(&op->dev, "stopping PPC-OF USB Controller\n");
@@ -201,6 +225,25 @@ static int ehci_hcd_ppc_of_remove(struct of_device *op)
         irq_dispose_mapping(hcd->irq);
         release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
 
+        /* use request_mem_region to test if the ohci driver is loaded.  if so
+         * ensure the ohci core is operational.
+         */
+        if (ehci->has_amcc_usb23) {
+                np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
+                if (np != NULL) {
+                        if (!of_address_to_resource(np, 0, &res))
+                                if (!request_mem_region(res.start,
+                                                            0x4, hcd_name))
+                                        set_ohci_hcfs(ehci, 1);
+                                else
+                                        release_mem_region(res.start, 0x4);
+                        else
+                                pr_debug(__FILE__ ": no ohci offset in fdt\n");
+                        of_node_put(np);
+                }
+
+                iounmap(ehci->ohci_hcctrl_reg);
+        }
         usb_put_hcd(hcd);
 
         return 0;
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index c7d4b5a06bdb..fb7054ccf4fc 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -120,6 +120,16 @@ struct ehci_hcd {			/* one per controller */
         unsigned                has_fsl_port_bug:1; /* FreeScale */
         unsigned                big_endian_mmio:1;
         unsigned                big_endian_desc:1;
+        unsigned                has_amcc_usb23:1;
+
+        /* required for usb32 quirk */
+        #define OHCI_CTRL_HCFS          (3 << 6)
+        #define OHCI_USB_OPER           (2 << 6)
+        #define OHCI_USB_SUSPEND        (3 << 6)
+
+        #define OHCI_HCCTRL_OFFSET      0x4
+        #define OHCI_HCCTRL_LEN         0x4
+        __hc32                  *ohci_hcctrl_reg;
 
         u8                      sbrn;           /* packed release number */
 
@@ -636,6 +646,30 @@ static inline void ehci_writel(const struct ehci_hcd *ehci,
 #endif
 }
 
+/*
+ * On certain ppc-44x SoC there is a HW issue, that could only worked around with
+ * explicit suspend/operate of OHCI. This function hereby makes sense only on that arch.
+ * Other common bits are dependant on has_amcc_usb23 quirk flag.
+ */
+#ifdef CONFIG_44x
+static inline void set_ohci_hcfs(struct ehci_hcd *ehci, int operational)
+{
+        u32 hc_control;
+
+        hc_control = (readl_be(ehci->ohci_hcctrl_reg) & ~OHCI_CTRL_HCFS);
+        if (operational)
+                hc_control |= OHCI_USB_OPER;
+        else
+                hc_control |= OHCI_USB_SUSPEND;
+
+        writel_be(hc_control, ehci->ohci_hcctrl_reg);
+        (void) readl_be(ehci->ohci_hcctrl_reg);
+}
+#else
+static inline void set_ohci_hcfs(struct ehci_hcd *ehci, int operational)
+{ }
+#endif
+
 /*-------------------------------------------------------------------------*/
 
 /*
diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index 7ac53264ead3..68a301710297 100644
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -91,6 +91,7 @@ ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
 
         int rv;
         int is_bigendian;
+        struct device_node *np;
 
         if (usb_disabled())
                 return -ENODEV;
@@ -147,6 +148,30 @@ ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
         if (rv == 0)
                 return 0;
 
+        /* by now, 440epx is known to show usb_23 erratum */
+        np = of_find_compatible_node(NULL, NULL, "ibm,usb-ehci-440epx");
+
+        /* Work around - At this point ohci_run has executed, the
+        * controller is running, everything, the root ports, etc., is
+        * set up.  If the ehci driver is loaded, put the ohci core in
+        * the suspended state.  The ehci driver will bring it out of
+        * suspended state when / if a non-high speed USB device is
+        * attached to the USB Host port.  If the ehci driver is not
+        * loaded, do nothing. request_mem_region is used to test if
+        * the ehci driver is loaded.
+        */
+        if (np !=  NULL) {
+                if (!of_address_to_resource(np, 0, &res)) {
+                        if (!request_mem_region(res.start, 0x4, hcd_name)) {
+                                writel_be((readl_be(&ohci->regs->control) |
+                                        OHCI_USB_SUSPEND), &ohci->regs->control);
+                                        (void) readl_be(&ohci->regs->control);
+                        } else
+                                release_mem_region(res.start, 0x4);
+                } else
+                    pr_debug(__FILE__ ": cannot get ehci offset from fdt\n");
+        }
+
         iounmap(hcd->regs);
 err_ioremap:
         irq_dispose_mapping(irq);