dm: Add base driver model support

Add driver model functionality for generic board.

This includes data structures and base code for registering devices and
uclasses (groups of devices with the same purpose, e.g. all I2C ports will
be in the same uclass).

The feature is enabled with CONFIG_DM.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: Viktor Křivák <viktor.krivak@gmail.com>
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/include/dm/uclass.h b/include/dm/uclass.h
new file mode 100644
index 0000000000..cd23cfed16
--- /dev/null
+++ b/include/dm/uclass.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * (C) Copyright 2012
+ * Pavel Herrmann <morpheus.ibis@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _DM_UCLASS_H
+#define _DM_UCLASS_H
+
+#include <dm/uclass-id.h>
+#include <linux/list.h>
+
+/**
+ * struct uclass - a U-Boot drive class, collecting together similar drivers
+ *
+ * A uclass provides an interface to a particular function, which is
+ * implemented by one or more drivers. Every driver belongs to a uclass even
+ * if it is the only driver in that uclass. An example uclass is GPIO, which
+ * provides the ability to change read inputs, set and clear outputs, etc.
+ * There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
+ * PMIC IO lines, all made available in a unified way through the uclass.
+ *
+ * @priv: Private data for this uclass
+ * @uc_drv: The driver for the uclass itself, not to be confused with a
+ * 'struct driver'
+ * dev_head: List of devices in this uclass (devices are attached to their
+ * uclass when their bind method is called)
+ * @sibling_node: Next uclass in the linked list of uclasses
+ */
+struct uclass {
+	void *priv;
+	struct uclass_driver *uc_drv;
+	struct list_head dev_head;
+	struct list_head sibling_node;
+};
+
+struct device;
+
+/**
+ * struct uclass_driver - Driver for the uclass
+ *
+ * A uclass_driver provides a consistent interface to a set of related
+ * drivers.
+ *
+ * @name: Name of uclass driver
+ * @id: ID number of this uclass
+ * @post_bind: Called after a new device is bound to this uclass
+ * @pre_unbind: Called before a device is unbound from this uclass
+ * @post_probe: Called after a new device is probed
+ * @pre_remove: Called before a device is removed
+ * @init: Called to set up the uclass
+ * @destroy: Called to destroy the uclass
+ * @priv_auto_alloc_size: If non-zero this is the size of the private data
+ * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
+ * driver is responsible for allocating any data required.
+ * @per_device_auto_alloc_size: Each device can hold private data owned
+ * by the uclass. If required this will be automatically allocated if this
+ * value is non-zero.
+ * @ops: Uclass operations, providing the consistent interface to devices
+ * within the uclass.
+ */
+struct uclass_driver {
+	const char *name;
+	enum uclass_id id;
+	int (*post_bind)(struct device *dev);
+	int (*pre_unbind)(struct device *dev);
+	int (*post_probe)(struct device *dev);
+	int (*pre_remove)(struct device *dev);
+	int (*init)(struct uclass *class);
+	int (*destroy)(struct uclass *class);
+	int priv_auto_alloc_size;
+	int per_device_auto_alloc_size;
+	const void *ops;
+};
+
+/* Declare a new uclass_driver */
+#define UCLASS_DRIVER(__name)						\
+	ll_entry_declare(struct uclass_driver, __name, uclass)
+
+/**
+ * uclass_get() - Get a uclass based on an ID, creating it if needed
+ *
+ * Every uclass is identified by an ID, a number from 0 to n-1 where n is
+ * the number of uclasses. This function allows looking up a uclass by its
+ * ID.
+ *
+ * @key: ID to look up
+ * @ucp: Returns pointer to uclass (there is only one per ID)
+ * @return 0 if OK, -ve on error
+ */
+int uclass_get(enum uclass_id key, struct uclass **ucp);
+
+/**
+ * uclass_get_device() - Get a uclass device based on an ID and index
+ *
+ * id: ID to look up
+ * @index: Device number within that uclass (0=first)
+ * @ucp: Returns pointer to uclass (there is only one per for each ID)
+ * @return 0 if OK, -ve on error
+ */
+int uclass_get_device(enum uclass_id id, int index, struct device **ucp);
+
+/**
+ * uclass_first_device() - Get the first device in a uclass
+ *
+ * @id: Uclass ID to look up
+ * @devp: Returns pointer to the first device in that uclass, or NULL if none
+ * @return 0 if OK (found or not found), -1 on error
+ */
+int uclass_first_device(enum uclass_id id, struct device **devp);
+
+/**
+ * uclass_next_device() - Get the next device in a uclass
+ *
+ * @devp: On entry, pointer to device to lookup. On exit, returns pointer
+ * to the next device in the same uclass, or NULL if none
+ * @return 0 if OK (found or not found), -1 on error
+ */
+int uclass_next_device(struct device **devp);
+
+/**
+ * uclass_foreach_dev() - Helper function to iteration through devices
+ *
+ * This creates a for() loop which works through the available devices in
+ * a uclass in order from start to end.
+ *
+ * @pos: struct device * to hold the current device. Set to NULL when there
+ * are no more devices.
+ * uc: uclass to scan
+ */
+#define uclass_foreach_dev(pos, uc)					\
+	for (pos = list_entry((&(uc)->dev_head)->next, typeof(*pos),	\
+			uclass_node);					\
+	     prefetch(pos->uclass_node.next),				\
+			&pos->uclass_node != (&(uc)->dev_head);		\
+	     pos = list_entry(pos->uclass_node.next, typeof(*pos),	\
+			uclass_node))
+
+#endif