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-controller.h b/include/linux/reset-controller.h
new file mode 100644
index 0000000..2f61311
--- /dev/null
+++ b/include/linux/reset-controller.h
@@ -0,0 +1,51 @@
+#ifndef _LINUX_RESET_CONTROLLER_H_
+#define _LINUX_RESET_CONTROLLER_H_
+
+#include <linux/list.h>
+
+struct reset_controller_dev;
+
+/**
+ * struct reset_control_ops
+ *
+ * @reset: for self-deasserting resets, does all necessary
+ * things to reset the device
+ * @assert: manually assert the reset line, if supported
+ * @deassert: manually deassert the reset line, if supported
+ */
+struct reset_control_ops {
+ int (*reset)(struct reset_controller_dev *rcdev, unsigned long id);
+ int (*assert)(struct reset_controller_dev *rcdev, unsigned long id);
+ int (*deassert)(struct reset_controller_dev *rcdev, unsigned long id);
+};
+
+struct module;
+struct device_node;
+
+/**
+ * struct reset_controller_dev - reset controller entity that might
+ * provide multiple reset controls
+ * @ops: a pointer to device specific struct reset_control_ops
+ * @owner: kernel module of the reset controller driver
+ * @list: internal list of reset controller devices
+ * @of_node: corresponding device tree node as phandle target
+ * @of_reset_n_cells: number of cells in reset line specifiers
+ * @of_xlate: translation function to translate from specifier as found in the
+ * device tree to id as given to the reset control ops
+ * @nr_resets: number of reset controls in this reset controller device
+ */
+struct reset_controller_dev {
+ struct reset_control_ops *ops;
+ struct module *owner;
+ struct list_head list;
+ struct device_node *of_node;
+ int of_reset_n_cells;
+ int (*of_xlate)(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *reset_spec);
+ unsigned int nr_resets;
+};
+
+int reset_controller_register(struct reset_controller_dev *rcdev);
+void reset_controller_unregister(struct reset_controller_dev *rcdev);
+
+#endif