USB: otg: sharable otg transceiver ops

Move otg_get/set/put_transceiver() from omap specific code
to common otg.c so other upcoming drivers can share them.

[ dbrownell@users.sourceforge.net: move to drivers/usb/otg, dox ]

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <me@felipebalbi.com>
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
new file mode 100644
index 000000000000..ff318fae7d4d
--- /dev/null
+++ b/drivers/usb/otg/otg.c
@@ -0,0 +1,65 @@
+/*
+ * otg.c -- USB OTG utility code
+ *
+ * Copyright (C) 2004 Texas Instruments
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include <linux/usb/otg.h>
+
+static struct otg_transceiver *xceiv;
+
+/**
+ * otg_get_transceiver - find the (single) OTG transceiver
+ *
+ * Returns the transceiver driver, after getting a refcount to it; or
+ * null if there is no such transceiver.  The caller is responsible for
+ * calling otg_put_transceiver() to release that count.
+ *
+ * For use by USB host and peripheral drivers.
+ */
+struct otg_transceiver *otg_get_transceiver(void)
+{
+	if (xceiv)
+		get_device(xceiv->dev);
+	return xceiv;
+}
+EXPORT_SYMBOL(otg_get_transceiver);
+
+/**
+ * otg_put_transceiver - release the (single) OTG transceiver
+ * @x: the transceiver returned by otg_get_transceiver()
+ *
+ * Releases a refcount the caller received from otg_get_transceiver().
+ *
+ * For use by USB host and peripheral drivers.
+ */
+void otg_put_transceiver(struct otg_transceiver *x)
+{
+	put_device(x->dev);
+}
+EXPORT_SYMBOL(otg_put_transceiver);
+
+/**
+ * otg_set_transceiver - declare the (single) OTG transceiver
+ * @x: the USB OTG transceiver to be used; or NULL
+ *
+ * This call is exclusively for use by transceiver drivers, which
+ * coordinate the activities of drivers for host and peripheral
+ * controllers, and in some cases for VBUS current regulation.
+ */
+int otg_set_transceiver(struct otg_transceiver *x)
+{
+	if (xceiv && x)
+		return -EBUSY;
+	xceiv = x;
+	return 0;
+}
+EXPORT_SYMBOL(otg_set_transceiver);