usb: chipidea: otg: add a_alt_hnp_support response for B device

This patch adds response to a_alt_hnp_support set feature request from legacy
A device, that is, B-device can provide a message to the user indicating that
the user needs to connect the B-device to an alternate port on the A-device.
A device sets this feature indicates to the B-device that it is connected
to an A-device port that is not capable of HNP, but that the A-device does have
an alternate port that is capable of HNP.

[Peter]
Without this patch, the OTG B device can't be enumerated on
non-HNP port at A device, see below log:
[    2.287464] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.293105] usb 1-1: can't set HNP mode: -32
[    2.417422] usb 1-1: new high-speed USB device number 4 using ci_hdrc
[    2.460635] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.466424] usb 1-1: can't set HNP mode: -32
[    2.587464] usb 1-1: new high-speed USB device number 5 using ci_hdrc
[    2.630649] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.636436] usb 1-1: can't set HNP mode: -32
[    2.641003] usb usb1-port1: unable to enumerate USB device

Cc: stable <stable@vger.kernel.org>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index ff451048c1ac..4bfb7ac0239f 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -929,6 +929,13 @@ __acquires(hwep->lock)
         return retval;
 }
 
+static int otg_a_alt_hnp_support(struct ci_hdrc *ci)
+{
+        dev_warn(&ci->gadget.dev,
+                "connect the device to an alternate port if you want HNP\n");
+        return isr_setup_status_phase(ci);
+}
+
 /**
  * isr_setup_packet_handler: setup packet handler
  * @ci: UDC descriptor
@@ -1061,6 +1068,10 @@ __acquires(ci->lock)
                                                         ci);
                                 }
                                 break;
+                        case USB_DEVICE_A_ALT_HNP_SUPPORT:
+                                if (ci_otg_is_fsm_mode(ci))
+                                        err = otg_a_alt_hnp_support(ci);
+                                break;
                         default:
                                 goto delegate;
                         }