usb: xhci: Add port test modes support for usb2.

For usb2 ports, the port test mode Test_J_State, Test_K_State,
Test_Packet, Test_SE0_NAK and Test_Force_En can be enabled
as described in usb2 spec.

USB2 test mode is a required hardware feature for system integrators
validating their hardware according to USB spec, regarding signal
strength and stuff. It is purely a hardware test feature.

Usually you need an oscilloscope and have to enable those test modes on
the hardware. This will send some specific test patterns on D+/D-. There
is no report available (in Linux itself) as it is purely externally
visible. Regular USB usage is not possible at that time.
Anyone (well access to e.g. /dev/bus/usb/001/001 provided) can use it by
sending appropriate USB_PORT_FEAT_TEST requests to the hub.

[Add better commit message by Alexander Stein  -Mathias]
Signed-off-by: Guoqing Zhang <guoqing.zhang@intel.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 04344c14180c0b7ab8ab16ba5ad5df7b1bd09f22..a0545fc367ca30722910fc51da1a27bf3c7708b0 100644 (file)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -583,6 +583,77 @@ static void xhci_set_port_power(struct xhci_hcd *xhci, struct usb_hcd *hcd,
        spin_lock_irqsave(&xhci->lock, flags);
 }
 
+static void xhci_port_set_test_mode(struct xhci_hcd *xhci,
+       u16 test_mode, u16 wIndex)
+{
+       u32 temp;
+       __le32 __iomem *addr;
+
+       /* xhci only supports test mode for usb2 ports, i.e. xhci->main_hcd */
+       addr = xhci_get_port_io_addr(xhci->main_hcd, wIndex);
+       temp = readl(addr + PORTPMSC);
+       temp |= test_mode << PORT_TEST_MODE_SHIFT;
+       writel(temp, addr + PORTPMSC);
+       xhci->test_mode = test_mode;
+       if (test_mode == TEST_FORCE_EN)
+               xhci_start(xhci);
+}
+
+static int xhci_enter_test_mode(struct xhci_hcd *xhci,
+                               u16 test_mode, u16 wIndex)
+{
+       int i, retval;
+
+       /* Disable all Device Slots */
+       xhci_dbg(xhci, "Disable all slots\n");
+       for (i = 1; i <= HCS_MAX_SLOTS(xhci->hcs_params1); i++) {
+               retval = xhci_disable_slot(xhci, NULL, i);
+               if (retval)
+                       xhci_err(xhci, "Failed to disable slot %d, %d. Enter test mode anyway\n",
+                                i, retval);
+       }
+       /* Put all ports to the Disable state by clear PP */
+       xhci_dbg(xhci, "Disable all port (PP = 0)\n");
+       /* Power off USB3 ports*/
+       for (i = 0; i < xhci->num_usb3_ports; i++)
+               xhci_set_port_power(xhci, xhci->shared_hcd, i, false);
+       /* Power off USB2 ports*/
+       for (i = 0; i < xhci->num_usb2_ports; i++)
+               xhci_set_port_power(xhci, xhci->main_hcd, i, false);
+       /* Stop the controller */
+       xhci_dbg(xhci, "Stop controller\n");
+       retval = xhci_halt(xhci);
+       if (retval)
+               return retval;
+       /* Disable runtime PM for test mode */
+       pm_runtime_forbid(xhci_to_hcd(xhci)->self.controller);
+       /* Set PORTPMSC.PTC field to enter selected test mode */
+       /* Port is selected by wIndex. port_id = wIndex + 1 */
+       xhci_dbg(xhci, "Enter Test Mode: %d, Port_id=%d\n",
+                                       test_mode, wIndex + 1);
+       xhci_port_set_test_mode(xhci, test_mode, wIndex);
+       return retval;
+}
+
+static int xhci_exit_test_mode(struct xhci_hcd *xhci)
+{
+       int retval;
+
+       if (!xhci->test_mode) {
+               xhci_err(xhci, "Not in test mode, do nothing.\n");
+               return 0;
+       }
+       if (xhci->test_mode == TEST_FORCE_EN &&
+               !(xhci->xhc_state & XHCI_STATE_HALTED)) {
+               retval = xhci_halt(xhci);
+               if (retval)
+                       return retval;
+       }
+       pm_runtime_allow(xhci_to_hcd(xhci)->self.controller);
+       xhci->test_mode = 0;
+       return xhci_reset(xhci);
+}
+
 void xhci_set_link_state(struct xhci_hcd *xhci, __le32 __iomem **port_array,
                                int port_id, u32 link_state)
 {
@@ -938,6 +1009,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
        u16 link_state = 0;
        u16 wake_mask = 0;
        u16 timeout = 0;
+       u16 test_mode = 0;
 
        max_ports = xhci_get_ports(hcd, &port_array);
        bus_state = &xhci->bus_state[hcd_index(hcd)];
@@ -1011,6 +1083,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                        link_state = (wIndex & 0xff00) >> 3;
                if (wValue == USB_PORT_FEAT_REMOTE_WAKE_MASK)
                        wake_mask = wIndex & 0xff00;
+               if (wValue == USB_PORT_FEAT_TEST)
+                       test_mode = (wIndex & 0xff00) >> 8;
                /* The MSB of wIndex is the U1/U2 timeout */
                timeout = (wIndex & 0xff00) >> 8;
                wIndex &= 0xff;
@@ -1174,6 +1248,14 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                        temp |= PORT_U2_TIMEOUT(timeout);
                        writel(temp, port_array[wIndex] + PORTPMSC);
                        break;
+               case USB_PORT_FEAT_TEST:
+                       /* 4.19.6 Port Test Modes (USB2 Test Mode) */
+                       if (hcd->speed != HCD_USB2)
+                               goto error;
+                       if (test_mode > TEST_FORCE_EN || test_mode < TEST_J)
+                               goto error;
+                       retval = xhci_enter_test_mode(xhci, test_mode, wIndex);
+                       break;
                default:
                        goto error;
                }
@@ -1241,6 +1323,9 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                case USB_PORT_FEAT_POWER:
                        xhci_set_port_power(xhci, hcd, wIndex, false);
                        break;
+               case USB_PORT_FEAT_TEST:
+                       retval = xhci_exit_test_mode(xhci);
+                       break;
                default:
                        goto error;
                }

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 4e12c8cb557a959d5074fccb5ad2ec1af80366ae..675d552e420e07154b35ac9a0501342669138851 100644 (file)
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -425,6 +425,7 @@ struct xhci_op_regs {
 #define        PORT_L1DS_MASK          (0xff << 8)
 #define        PORT_L1DS(p)            (((p) & 0xff) << 8)
 #define        PORT_HLE                (1 << 16)
+#define PORT_TEST_MODE_SHIFT   28
 
 /* USB3 Protocol PORTLI  Port Link Information */
 #define PORT_RX_LANES(p)       (((p) >> 16) & 0xf)
@@ -1843,6 +1844,7 @@ struct xhci_hcd {
        /* Compliance Mode Recovery Data */
        struct timer_list       comp_mode_recovery_timer;
        u32                     port_status_u0;
+       u16                     test_mode;
 /* Compliance Mode Timer Triggered every 2 seconds */
 #define COMP_MODE_RCVRY_MSECS 2000