* Add a ioctls for adding/removing nodes using binary blobs.
Signed-off-by: Alan Tull <at...@altera.com>
---
drivers/of/Makefile | 1 +
drivers/of/dynamic.c | 287 ++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/of/dynamic.h | 26 +++++
3 files changed, 314 insertions(+), 0 deletions(-)
create mode 100644 drivers/of/dynamic.c
create mode 100644 drivers/of/dynamic.h
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index e027f44..5c08045 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_OF_PROMTREE) += pdt.o
obj-$(CONFIG_OF_ADDRESS) += address.o
obj-$(CONFIG_OF_IRQ) += irq.o
obj-$(CONFIG_OF_DEVICE) += device.o platform.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
obj-$(CONFIG_OF_I2C) += of_i2c.o
obj-$(CONFIG_OF_NET) += of_net.o
obj-$(CONFIG_OF_SELFTEST) += selftest.o
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
new file mode 100644
index 0000000..0dce177
--- /dev/null
+++ b/drivers/of/dynamic.c
@@ -0,0 +1,287 @@
+/*
+ * Dynamic Device Tree support
+ *
+ * Copyright (C) 2012 Altera Corporation
+ * Author: Alan Tull <at...@altera.com>
+ *
+ * Some code taken from reconfig.c
+ * Copyright (C) 2005 Nathan Lynch
+ * Copyright (C) 2005 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include "dynamic.h"
+
+static int major;
+module_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+
+static DEFINE_MUTEX(of_dynamic_ioctl_mutex);
+
+/*
+ * Routines for "runtime" addition and removal of device tree nodes.
+ */
+#ifdef CONFIG_PROC_DEVICETREE
+/*
+ * Add a node to /proc/device-tree.
+ */
+static void add_node_proc_entries(struct device_node *np)
+{
+ struct proc_dir_entry *ent;
+
+ pr_debug("%s parent........... %s\n", __func__, np->parent->name);
+ pr_debug("%s full_name........ %s\n", __func__, np->full_name);
+
+ ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
+ if (ent)
+ proc_device_tree_add_node(np, ent);
+}
+
+static void remove_node_proc_entries(struct device_node *np)
+{
+ struct property *pp = np->properties;
+ struct device_node *parent = np->parent;
+
+ while (pp) {
+ remove_proc_entry(pp->name, np->pde);
+ pp = pp->next;
+ }
+ if (np->pde)
+ remove_proc_entry(np->pde->name, parent->pde);
+}
+#else /* !CONFIG_PROC_DEVICETREE */
+static void add_node_proc_entries(struct device_node *np)
+{
+ return;
+}
+
+static void remove_node_proc_entries(struct device_node *np)
+{
+ return;
+}
+#endif /* CONFIG_PROC_DEVICETREE */
+
+/*
+ * derive_parent - basically like dirname(1)
+ * @path: the full_name of a node to be added to the tree
+ *
+ * Returns the node which should be the parent of the node
+ * described by path. E.g., for path = "/foo/bar", returns
+ * the node with full_name = "/foo".
+ */
+static struct device_node *derive_parent(const char *path)
+{
+ struct device_node *parent = NULL;
+ char *parent_path = "/";
+ size_t parent_path_len = strrchr(path, '/') - path + 1;
+
+ /* reject if path is "/" */
+ if (!strcmp(path, "/"))
+ return ERR_PTR(-EINVAL);
+
+ if (strrchr(path, '/') != path) {
+ parent_path = kmalloc(parent_path_len, GFP_KERNEL);
+ if (!parent_path)
+ return ERR_PTR(-ENOMEM);
+ strlcpy(parent_path, path, parent_path_len);
+ }
+ parent = of_find_node_by_path(parent_path);
+ if (!parent)
+ return ERR_PTR(-EINVAL);
+ if (strcmp(parent_path, "/"))
+ kfree(parent_path);
+ return parent;
+}
+
+static void next_real_node(struct device_node **npp)
+{
+ /* The blob to be added is not a complete device tree. Some nodes'
+ parents are only there to indicate the path to add the node
+ in the existing tree. Look for nodes that have real properties
+ besides name (i.e. compatible) and add those recursively. */
+
+ /* Mark the nodes we don't attach for removal */
+ while ((*npp) && !of_get_property(*npp, "compatible", NULL)) {
+ of_node_set_flag(*npp, OF_DETACHED);
+ *npp = (*npp)->next;
+ }
+}
+
+static int add_nodes_to_tree(struct device_node *np)
+{
+ struct device_node *tree_node;
+
+ while (np) {
+ next_real_node(&np);
+ if (np) {
+ tree_node = of_find_node_by_path(np->full_name);
+ if (tree_node) {
+ pr_err("%s Error: node %s exists in device
tree\n",
+ __func__, np->full_name);
+ of_node_put(tree_node);
+ return -EEXIST;
+ }
+
+ np->parent = derive_parent(np->full_name);
+ if (IS_ERR(np->parent))
+ return -EINVAL;
+ of_attach_node(np);
+ add_node_proc_entries(np);
+
+ of_node_put(np->parent);
+ np = np->next;
+ }
+ }
+
+ return 0;
+}
+
+static int remove_nodes_from_tree(struct device_node *np)
+{
+ struct device_node *tree_node;
+
+ while (np) {
+ next_real_node(&np);
+ if (np) {
+ tree_node = of_find_node_by_path(np->full_name);
+ if (!tree_node) {
+ pr_err("%s Error: node %s does not exist in
device tree\n",
+ __func__, np->full_name);
+ return -ENOENT;
+ }
+
+ remove_node_proc_entries(tree_node);
+ of_detach_node(tree_node);
+ of_node_put(tree_node);
+
+ of_node_put(np->parent);
+ np = np->next;
+ }
+ }
+
+ return 0;
+}
+
+static long of_dynamic_unlocked_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+ void *blob = NULL;
+ struct device_node *np;
+ void __user *user_arg = (void __user *)arg;
+ struct of_dynamic_blob_info blob_info;
+
+ pr_debug("%s\n", __func__);
+
+ mutex_lock(&of_dynamic_ioctl_mutex);
+
+ if (copy_from_user(&blob_info, user_arg, sizeof(blob_info))) {
+ pr_err("%s copy_from_user error\n", __func__);
+ ret = -EINVAL;
+ goto ioctl_out;
+ }
+
+ blob = kmalloc(blob_info.size, GFP_KERNEL);
+ if (!blob) {
+ ret = -ENOMEM;
+ goto ioctl_out;
+ }
+
+ if (copy_from_user(blob, blob_info.blob, blob_info.size)) {
+ ret = -EFAULT;
+ goto ioctl_out;
+ }
+
+ of_fdt_unflatten_tree(blob, &np);
+
+ switch (cmd) {
+ case OF_DYNAMIC_ADD_NODE:
+ pr_debug("%s : cmd = OF_DYNAMIC_ADD_NODE size = %d\n",
+ __func__, blob_info.size);
+ ret = add_nodes_to_tree(np);
+ break;
+
+ case OF_DYNAMIC_REMOVE_NODE:
+ pr_debug("%s : cmd = OF_DYNAMIC_REMOVE_NODE\n", __func__);
+ ret = remove_nodes_from_tree(np);
+ break;
+
+ default:
+ pr_debug("%s : unknown ioctl %d blob size = %d\n",
+ __func__, cmd, blob_info.size);
+ ret = -EINVAL;
+ break;
+ }
+
+ioctl_out:
+ kfree(blob);
+ mutex_unlock(&of_dynamic_ioctl_mutex);
+ return ret;
+}
+
+static const struct file_operations of_dynamic_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .unlocked_ioctl = of_dynamic_unlocked_ioctl,
+};
+
+static struct cdev of_dynamic_dev;
+
+static int __init of_dynamic_init(void)
+{
+ int rc;
+ dev_t dev;
+
+ if (major) {
+ dev = MKDEV(major, 0);
+ rc = register_chrdev_region(dev, 1, "of_dynamic");
+ } else {
+ rc = alloc_chrdev_region(&dev, 0, 1, "of_dynamic");
+ major = MAJOR(dev);
+ }
+ if (rc < 0) {
+ pr_err("of_dynamic chrdev_region err: %d\n", rc);
+ return rc;
+ }
+
+ cdev_init(&of_dynamic_dev, &of_dynamic_fops);
+ rc = cdev_add(&of_dynamic_dev, dev, 1);
+ if (rc < 0)
+ return rc;
+
+ return 0;
+}
+
+static void __exit of_dynamic_exit(void)
+{
+ unregister_chrdev_region(MKDEV(major, 0), 1);
+}
+
+module_init(of_dynamic_init);
+module_exit(of_dynamic_exit);
+
+MODULE_AUTHOR("Alan Tull <at...@altera.com>");
+MODULE_DESCRIPTION("Dynamic device tree");
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/dynamic.h b/drivers/of/dynamic.h
new file mode 100644
index 0000000..4ee4e96
--- /dev/null
+++ b/drivers/of/dynamic.h
@@ -0,0 +1,26 @@
+/*
+ * Dynamic Device Tree support
+ *
+ * Copyrignt (C) 2012 Altera Corporation
+ *
+ */
+
+#ifndef __OF_DYNAMIC_H
+#define __OF_DYNAMIC_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+struct of_dynamic_blob_info {
+ __u32 size;
+ __u8 *blob;
+};
+
+/*
+ * TODO pick some unused ioctls (see Documentation/ioctl/ioctl-number-txt)
+ * and ask mec to register them
+ */
+#define OF_DYNAMIC_ADD_NODE _IOW('W', 0, struct of_dynamic_blob_info *)
+#define OF_DYNAMIC_REMOVE_NODE _IOW('W', 1, struct of_dynamic_blob_info *)
+
+#endif /* __OF_DYNAMIC_H */
--
1.7.1
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