USB: Enable finer grain control over init process

Previously enabling USB would automatically (using an
init hook) initialize the USB peripheral.  This would
take over the GPIO lines assigned to the USB module.
This is not OK on Ryu for Case Closed Debug because it
interferes with the AP's access to the USB 2.0 lines
even when not in Case Close Debug mode.

This change adds a configuration option to inhibit this
default initialization of the USB peripheral.  It also
renames the existing CONFIG_USB_INHIBIT to
CONFIG_USB_INHIBIT_CONNECT now that there are two
possible inhibitions.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
TEST=make buildall -j
     Enable console on ryu_p2 and discovery-stm32f072 board
     Verify that it works on both

Change-Id: I6734357131b4356e3d4164349d6c74deac196ce5
Reviewed-on: https://chromium-review.googlesource.com/229138
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>
Tested-by: Anton Staaf <robotboy@chromium.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/usb_api.h b/include/usb_api.h
index feeb6abb27..dc0a0fd654 100644
--- a/include/usb_api.h
+++ b/include/usb_api.h
@@ -14,9 +14,10 @@
 
 /*
  * Initialize the USB peripheral, enabling its clock and configuring the DP/DN
- * GPIOs correctly.  This function is called via an init hook, but may need to
- * be called again if usb_release is called.  This function will call
- * usb_connect by default unless CONFIG_USB_INHIBIT is defined.
+ * GPIOs correctly.  This function is called via an init hook (unless the board
+ * defined CONFIG_USB_INHIBIT_INIT), but may need to be called again if
+ * usb_release is called.  This function will call usb_connect by default
+ * unless CONFIG_USB_INHIBIT_CONNECT is defined.
  */
 void usb_init(void);