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authorLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2009-01-08 13:22:55 +1100
committerLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2009-01-08 13:22:55 +1100
commit6206aa8b2b9a45b4cf3ee31b7209b014be349fd9 (patch)
tree72c4223a2cc21bf055948eadb3b314ed0568ae9d /drivers/usb/otg/otg.c
parent95f8e302c04c0b0c6de35ab399a5551605eeb006 (diff)
parent9e42d0cf5020aaf217433cad1a224745241d212a (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'drivers/usb/otg/otg.c')
-rw-r--r--drivers/usb/otg/otg.c65
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 00000000000..ff318fae7d4
--- /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);