USB: otg: gpio_vbus transceiver stub

gpio_vbus provides simple GPIO VBUS sensing for peripheral
controllers with an internal transceiver.
Optionally, a second GPIO can be used to control D+ pullup.

It also interfaces with the regulator framework to limit charging
currents when powered via USB. gpio_vbus requests the regulator
supplying "vbus_draw" and can enable/disable it or limit its
current depending on USB state.

[dbrownell@users.sourceforge.net: use drivers/otg, cleanups ]

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, 30 insertions, 0 deletions

diff --git a/include/linux/usb/gpio_vbus.h b/include/linux/usb/gpio_vbus.h
new file mode 100644
index 000000000000..d9f03ccc2d60
--- /dev/null
+++ b/include/linux/usb/gpio_vbus.h
@@ -0,0 +1,30 @@
+/*
+ * A simple GPIO VBUS sensing driver for B peripheral only devices
+ * with internal transceivers.
+ * Optionally D+ pullup can be controlled by a second GPIO.
+ *
+ * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+/**
+ * struct gpio_vbus_mach_info - configuration for gpio_vbus
+ * @gpio_vbus: VBUS sensing GPIO
+ * @gpio_pullup: optional D+ or D- pullup GPIO (else negative/invalid)
+ * @gpio_vbus_inverted: true if gpio_vbus is active low
+ * @gpio_pullup_inverted: true if gpio_pullup is active low
+ *
+ * The VBUS sensing GPIO should have a pulldown, which will normally be
+ * part of a resistor ladder turning a 4.0V-5.25V level on VBUS into a
+ * value the GPIO detects as active.  Some systems will use comparators.
+ */
+struct gpio_vbus_mach_info {
+        int gpio_vbus;
+        int gpio_pullup;
+        bool gpio_vbus_inverted;
+        bool gpio_pullup_inverted;
+};