reset: add reset controller framework

Add stripped sown version of the reset controller
framework from the Linux kernel.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 117 insertions, 0 deletions

diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
new file mode 100644
index 0000000000..d8265486a0
--- /dev/null
+++ b/include/linux/reset-controller.h
@@ -0,0 +1,50 @@
+#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 device_node;
+struct of_phandle_args;
+
+/**
+ * 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 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
diff --git a/include/linux/reset.h b/include/linux/reset.h
new file mode 100644
index 0000000000..f6c475c68b
--- /dev/null
+++ b/include/linux/reset.h
@@ -0,0 +1,67 @@
+#ifndef _LINUX_RESET_H_
+#define _LINUX_RESET_H_
+
+struct device_d;
+struct reset_control;
+
+#ifdef CONFIG_RESET_CONTROLLER
+
+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_d *dev, const char *id);
+void reset_control_put(struct reset_control *rstc);
+
+int __must_check device_reset(struct device_d *dev);
+
+static inline int device_reset_optional(struct device_d *dev)
+{
+	return device_reset(dev);
+}
+
+static inline struct reset_control *reset_control_get_optional(
+					struct device_d *dev, const char *id)
+{
+	return reset_control_get(dev, id);
+}
+
+#else
+
+static inline int reset_control_reset(struct reset_control *rstc)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static inline int reset_control_assert(struct reset_control *rstc)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static inline int reset_control_deassert(struct reset_control *rstc)
+{
+	WARN_ON(1);
+	return 0;
+}
+
+static inline void reset_control_put(struct reset_control *rstc)
+{
+	WARN_ON(1);
+}
+
+static inline int device_reset_optional(struct device_d *dev)
+{
+	return -ENOSYS;
+}
+
+static inline struct reset_control *reset_control_get_optional(
+					struct device_d *dev, const char *id)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+#endif /* CONFIG_RESET_CONTROLLER */
+
+#endif