arch/tile: provide kernel support for the tilegx USB shim

This change adds support for accessing the USB shim from within the
kernel.  Note that this change by itself does not allow the kernel
to act as a host or as a device; it merely exposes the built-in on-chip
hardware to the kernel.

The <arch/usb_host.h> and <arch/usb_host_def.h> headers are empty at
the moment because the kernel does not require any types or definitions
specific to the tilegx USB shim; the generic USB core code is all we need.
The headers are left in as stubs so that we don't need to modify the
hypervisor header (drv_usb_host_intf.h) from upstream.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/arch/tile/include/gxio/usb_host.h b/arch/tile/include/gxio/usb_host.h
new file mode 100644
index 000000000000..a60a126e4565
--- /dev/null
+++ b/arch/tile/include/gxio/usb_host.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+#ifndef _GXIO_USB_H_
+#define _GXIO_USB_H_
+
+#include "common.h"
+
+#include <hv/drv_usb_host_intf.h>
+#include <hv/iorpc.h>
+
+/*
+ *
+ * An API for manipulating general-purpose I/O pins.
+ */
+
+/*
+ *
+ * The USB shim allows access to the processor's Universal Serial Bus
+ * connections.
+ */
+
+/* A context object used to manage USB hardware resources. */
+typedef struct {
+
+	/* File descriptor for calling up to the hypervisor. */
+	int fd;
+
+	/* The VA at which our MMIO registers are mapped. */
+	char *mmio_base;
+} gxio_usb_host_context_t;
+
+/* Initialize a USB context.
+ *
+ *  A properly initialized context must be obtained before any of the other
+ *  gxio_usb_host routines may be used.
+ *
+ * @param context Pointer to a gxio_usb_host_context_t, which will be
+ *  initialized by this routine, if it succeeds.
+ * @param usb_index Index of the USB shim to use.
+ * @param is_ehci Nonzero to use the EHCI interface; zero to use the OHCI
+ *  intereface.
+ * @return Zero if the context was successfully initialized, else a
+ *  GXIO_ERR_xxx error code.
+ */
+extern int gxio_usb_host_init(gxio_usb_host_context_t * context, int usb_index,
+			      int is_ehci);
+
+/* Destroy a USB context.
+ *
+ *  Once destroyed, a context may not be used with any gxio_usb_host routines
+ *  other than gxio_usb_host_init().  After this routine returns, no further
+ *  interrupts or signals requested on this context will be delivered.  The
+ *  state and configuration of the pins which had been attached to this
+ *  context are unchanged by this operation.
+ *
+ * @param context Pointer to a gxio_usb_host_context_t.
+ * @return Zero if the context was successfully destroyed, else a
+ *  GXIO_ERR_xxx error code.
+ */
+extern int gxio_usb_host_destroy(gxio_usb_host_context_t * context);
+
+/* Retrieve the address of the shim's MMIO registers.
+ *
+ * @param context Pointer to a properly initialized gxio_usb_host_context_t.
+ * @return The address of the shim's MMIO registers.
+ */
+extern void *gxio_usb_host_get_reg_start(gxio_usb_host_context_t * context);
+
+/* Retrieve the length of the shim's MMIO registers.
+ *
+ * @param context Pointer to a properly initialized gxio_usb_host_context_t.
+ * @return The length of the shim's MMIO registers.
+ */
+extern size_t gxio_usb_host_get_reg_len(gxio_usb_host_context_t * context);
+
+#endif /* _GXIO_USB_H_ */