reset: Add reset controller API

This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
diff --git a/include/linux/reset.h b/include/linux/reset.h
new file mode 100644
index 0000000..6082247
--- /dev/null
+++ b/include/linux/reset.h
@@ -0,0 +1,17 @@
+#ifndef _LINUX_RESET_H_
+#define _LINUX_RESET_H_
+
+struct device;
+struct reset_control;
+
+int reset_control_reset(struct reset_control *rstc);
+int reset_control_assert(struct reset_control *rstc);
+int reset_control_deassert(struct reset_control *rstc);
+
+struct reset_control *reset_control_get(struct device *dev, const char *id);
+void reset_control_put(struct reset_control *rstc);
+struct reset_control *devm_reset_control_get(struct device *dev, const char *id);
+
+int device_reset(struct device *dev);
+
+#endif