+++ /dev/null
-From dc0f4681729e9bfe506ab8b15852363cb59bdaf5 Mon Sep 17 00:00:00 2001
-From: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
-Date: Wed, 3 Dec 2014 13:23:28 +0200
-Subject: [PATCH] OF: DT-Overlay configfs interface
-
-This is a port of Pantelis Antoniou's v3 port that makes use of the
-new upstreamed configfs support for binary attributes.
-
-Original commit message:
-
-Add a runtime interface to using configfs for generic device tree overlay
-usage. With it its possible to use device tree overlays without having
-to use a per-platform overlay manager.
-
-Please see Documentation/devicetree/configfs-overlays.txt for more info.
-
-Changes since v2:
-- Removed ifdef CONFIG_OF_OVERLAY (since for now it's required)
-- Created a documentation entry
-- Slight rewording in Kconfig
-
-Changes since v1:
-- of_resolve() -> of_resolve_phandles().
-
-Originally-signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
-Signed-off-by: Phil Elwell <phil@raspberrypi.org>
-
-DT configfs: Fix build errors on other platforms
-
-Signed-off-by: Phil Elwell <phil@raspberrypi.org>
-
-DT configfs: fix build error
-
-There is an error when compiling rpi-4.6.y branch:
- CC drivers/of/configfs.o
-drivers/of/configfs.c:291:21: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
- .default_groups = of_cfs_def_groups,
- ^
-drivers/of/configfs.c:291:21: note: (near initialization for 'of_cfs_subsys.su_group.default_groups.next')
-
-The .default_groups is linked list since commit
-1ae1602de028acaa42a0f6ff18d19756f8e825c6.
-This commit uses configfs_add_default_group to fix this problem.
-
-Signed-off-by: Slawomir Stepien <sst@poczta.fm>
-
-configfs: New of_overlay API
----
- .../devicetree/configfs-overlays.txt | 31 ++
- drivers/of/Kconfig | 7 +
- drivers/of/Makefile | 1 +
- drivers/of/configfs.c | 310 ++++++++++++++++++
- 4 files changed, 349 insertions(+)
- create mode 100644 Documentation/devicetree/configfs-overlays.txt
- create mode 100644 drivers/of/configfs.c
-
---- /dev/null
-+++ b/Documentation/devicetree/configfs-overlays.txt
-@@ -0,0 +1,31 @@
-+Howto use the configfs overlay interface.
-+
-+A device-tree configfs entry is created in /config/device-tree/overlays
-+and and it is manipulated using standard file system I/O.
-+Note that this is a debug level interface, for use by developers and
-+not necessarily something accessed by normal users due to the
-+security implications of having direct access to the kernel's device tree.
-+
-+* To create an overlay you mkdir the directory:
-+
-+ # mkdir /config/device-tree/overlays/foo
-+
-+* Either you echo the overlay firmware file to the path property file.
-+
-+ # echo foo.dtbo >/config/device-tree/overlays/foo/path
-+
-+* Or you cat the contents of the overlay to the dtbo file
-+
-+ # cat foo.dtbo >/config/device-tree/overlays/foo/dtbo
-+
-+The overlay file will be applied, and devices will be created/destroyed
-+as required.
-+
-+To remove it simply rmdir the directory.
-+
-+ # rmdir /config/device-tree/overlays/foo
-+
-+The rationalle of the dual interface (firmware & direct copy) is that each is
-+better suited to different use patterns. The firmware interface is what's
-+intended to be used by hardware managers in the kernel, while the copy interface
-+make sense for developers (since it avoids problems with namespaces).
---- a/drivers/of/Kconfig
-+++ b/drivers/of/Kconfig
-@@ -104,4 +104,11 @@ config OF_OVERLAY
- config OF_NUMA
- bool
-
-+config OF_CONFIGFS
-+ bool "Device Tree Overlay ConfigFS interface"
-+ select CONFIGFS_FS
-+ select OF_OVERLAY
-+ help
-+ Enable a simple user-space driven DT overlay interface.
-+
- endif # OF
---- a/drivers/of/Makefile
-+++ b/drivers/of/Makefile
-@@ -1,6 +1,7 @@
- # SPDX-License-Identifier: GPL-2.0
- obj-y = base.o device.o platform.o property.o
- obj-$(CONFIG_OF_KOBJ) += kobj.o
-+obj-$(CONFIG_OF_CONFIGFS) += configfs.o
- obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
- obj-$(CONFIG_OF_FLATTREE) += fdt.o
- obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
---- /dev/null
-+++ b/drivers/of/configfs.c
-@@ -0,0 +1,310 @@
-+/*
-+ * Configfs entries for device-tree
-+ *
-+ * Copyright (C) 2013 - Pantelis Antoniou <panto@antoniou-consulting.com>
-+ *
-+ * 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.
-+ */
-+#include <linux/ctype.h>
-+#include <linux/cpu.h>
-+#include <linux/module.h>
-+#include <linux/of.h>
-+#include <linux/of_fdt.h>
-+#include <linux/spinlock.h>
-+#include <linux/slab.h>
-+#include <linux/proc_fs.h>
-+#include <linux/configfs.h>
-+#include <linux/types.h>
-+#include <linux/stat.h>
-+#include <linux/limits.h>
-+#include <linux/file.h>
-+#include <linux/vmalloc.h>
-+#include <linux/firmware.h>
-+#include <linux/sizes.h>
-+
-+#include "of_private.h"
-+
-+struct cfs_overlay_item {
-+ struct config_item item;
-+
-+ char path[PATH_MAX];
-+
-+ const struct firmware *fw;
-+ struct device_node *overlay;
-+ int ov_id;
-+
-+ void *dtbo;
-+ int dtbo_size;
-+};
-+
-+static int create_overlay(struct cfs_overlay_item *overlay, void *blob)
-+{
-+ int err;
-+
-+ /* unflatten the tree */
-+ of_fdt_unflatten_tree(blob, NULL, &overlay->overlay);
-+ if (overlay->overlay == NULL) {
-+ pr_err("%s: failed to unflatten tree\n", __func__);
-+ err = -EINVAL;
-+ goto out_err;
-+ }
-+ pr_debug("%s: unflattened OK\n", __func__);
-+
-+ /* mark it as detached */
-+ of_node_set_flag(overlay->overlay, OF_DETACHED);
-+
-+ /* perform resolution */
-+ err = of_resolve_phandles(overlay->overlay);
-+ if (err != 0) {
-+ pr_err("%s: Failed to resolve tree\n", __func__);
-+ goto out_err;
-+ }
-+ pr_debug("%s: resolved OK\n", __func__);
-+
-+ err = of_overlay_apply(overlay->overlay, &overlay->ov_id);
-+ if (err < 0) {
-+ pr_err("%s: Failed to create overlay (err=%d)\n",
-+ __func__, err);
-+ goto out_err;
-+ }
-+
-+out_err:
-+ return err;
-+}
-+
-+static inline struct cfs_overlay_item *to_cfs_overlay_item(
-+ struct config_item *item)
-+{
-+ return item ? container_of(item, struct cfs_overlay_item, item) : NULL;
-+}
-+
-+static ssize_t cfs_overlay_item_path_show(struct config_item *item,
-+ char *page)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+ return sprintf(page, "%s\n", overlay->path);
-+}
-+
-+static ssize_t cfs_overlay_item_path_store(struct config_item *item,
-+ const char *page, size_t count)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+ const char *p = page;
-+ char *s;
-+ int err;
-+
-+ /* if it's set do not allow changes */
-+ if (overlay->path[0] != '\0' || overlay->dtbo_size > 0)
-+ return -EPERM;
-+
-+ /* copy to path buffer (and make sure it's always zero terminated */
-+ count = snprintf(overlay->path, sizeof(overlay->path) - 1, "%s", p);
-+ overlay->path[sizeof(overlay->path) - 1] = '\0';
-+
-+ /* strip trailing newlines */
-+ s = overlay->path + strlen(overlay->path);
-+ while (s > overlay->path && *--s == '\n')
-+ *s = '\0';
-+
-+ pr_debug("%s: path is '%s'\n", __func__, overlay->path);
-+
-+ err = request_firmware(&overlay->fw, overlay->path, NULL);
-+ if (err != 0)
-+ goto out_err;
-+
-+ err = create_overlay(overlay, (void *)overlay->fw->data);
-+ if (err != 0)
-+ goto out_err;
-+
-+ return count;
-+
-+out_err:
-+
-+ release_firmware(overlay->fw);
-+ overlay->fw = NULL;
-+
-+ overlay->path[0] = '\0';
-+ return err;
-+}
-+
-+static ssize_t cfs_overlay_item_status_show(struct config_item *item,
-+ char *page)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+
-+ return sprintf(page, "%s\n",
-+ overlay->ov_id >= 0 ? "applied" : "unapplied");
-+}
-+
-+CONFIGFS_ATTR(cfs_overlay_item_, path);
-+CONFIGFS_ATTR_RO(cfs_overlay_item_, status);
-+
-+static struct configfs_attribute *cfs_overlay_attrs[] = {
-+ &cfs_overlay_item_attr_path,
-+ &cfs_overlay_item_attr_status,
-+ NULL,
-+};
-+
-+ssize_t cfs_overlay_item_dtbo_read(struct config_item *item,
-+ void *buf, size_t max_count)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+
-+ pr_debug("%s: buf=%p max_count=%zu\n", __func__,
-+ buf, max_count);
-+
-+ if (overlay->dtbo == NULL)
-+ return 0;
-+
-+ /* copy if buffer provided */
-+ if (buf != NULL) {
-+ /* the buffer must be large enough */
-+ if (overlay->dtbo_size > max_count)
-+ return -ENOSPC;
-+
-+ memcpy(buf, overlay->dtbo, overlay->dtbo_size);
-+ }
-+
-+ return overlay->dtbo_size;
-+}
-+
-+ssize_t cfs_overlay_item_dtbo_write(struct config_item *item,
-+ const void *buf, size_t count)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+ int err;
-+
-+ /* if it's set do not allow changes */
-+ if (overlay->path[0] != '\0' || overlay->dtbo_size > 0)
-+ return -EPERM;
-+
-+ /* copy the contents */
-+ overlay->dtbo = kmemdup(buf, count, GFP_KERNEL);
-+ if (overlay->dtbo == NULL)
-+ return -ENOMEM;
-+
-+ overlay->dtbo_size = count;
-+
-+ err = create_overlay(overlay, overlay->dtbo);
-+ if (err != 0)
-+ goto out_err;
-+
-+ return count;
-+
-+out_err:
-+ kfree(overlay->dtbo);
-+ overlay->dtbo = NULL;
-+ overlay->dtbo_size = 0;
-+
-+ return err;
-+}
-+
-+CONFIGFS_BIN_ATTR(cfs_overlay_item_, dtbo, NULL, SZ_1M);
-+
-+static struct configfs_bin_attribute *cfs_overlay_bin_attrs[] = {
-+ &cfs_overlay_item_attr_dtbo,
-+ NULL,
-+};
-+
-+static void cfs_overlay_release(struct config_item *item)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+
-+ if (overlay->ov_id >= 0)
-+ of_overlay_remove(&overlay->ov_id);
-+ if (overlay->fw)
-+ release_firmware(overlay->fw);
-+ /* kfree with NULL is safe */
-+ kfree(overlay->dtbo);
-+ kfree(overlay);
-+}
-+
-+static struct configfs_item_operations cfs_overlay_item_ops = {
-+ .release = cfs_overlay_release,
-+};
-+
-+static struct config_item_type cfs_overlay_type = {
-+ .ct_item_ops = &cfs_overlay_item_ops,
-+ .ct_attrs = cfs_overlay_attrs,
-+ .ct_bin_attrs = cfs_overlay_bin_attrs,
-+ .ct_owner = THIS_MODULE,
-+};
-+
-+static struct config_item *cfs_overlay_group_make_item(
-+ struct config_group *group, const char *name)
-+{
-+ struct cfs_overlay_item *overlay;
-+
-+ overlay = kzalloc(sizeof(*overlay), GFP_KERNEL);
-+ if (!overlay)
-+ return ERR_PTR(-ENOMEM);
-+ overlay->ov_id = -1;
-+
-+ config_item_init_type_name(&overlay->item, name, &cfs_overlay_type);
-+ return &overlay->item;
-+}
-+
-+static void cfs_overlay_group_drop_item(struct config_group *group,
-+ struct config_item *item)
-+{
-+ struct cfs_overlay_item *overlay = to_cfs_overlay_item(item);
-+
-+ config_item_put(&overlay->item);
-+}
-+
-+static struct configfs_group_operations overlays_ops = {
-+ .make_item = cfs_overlay_group_make_item,
-+ .drop_item = cfs_overlay_group_drop_item,
-+};
-+
-+static struct config_item_type overlays_type = {
-+ .ct_group_ops = &overlays_ops,
-+ .ct_owner = THIS_MODULE,
-+};
-+
-+static struct configfs_group_operations of_cfs_ops = {
-+ /* empty - we don't allow anything to be created */
-+};
-+
-+static struct config_item_type of_cfs_type = {
-+ .ct_group_ops = &of_cfs_ops,
-+ .ct_owner = THIS_MODULE,
-+};
-+
-+struct config_group of_cfs_overlay_group;
-+
-+static struct configfs_subsystem of_cfs_subsys = {
-+ .su_group = {
-+ .cg_item = {
-+ .ci_namebuf = "device-tree",
-+ .ci_type = &of_cfs_type,
-+ },
-+ },
-+ .su_mutex = __MUTEX_INITIALIZER(of_cfs_subsys.su_mutex),
-+};
-+
-+static int __init of_cfs_init(void)
-+{
-+ int ret;
-+
-+ pr_info("%s\n", __func__);
-+
-+ config_group_init(&of_cfs_subsys.su_group);
-+ config_group_init_type_name(&of_cfs_overlay_group, "overlays",
-+ &overlays_type);
-+ configfs_add_default_group(&of_cfs_overlay_group,
-+ &of_cfs_subsys.su_group);
-+
-+ ret = configfs_register_subsystem(&of_cfs_subsys);
-+ if (ret != 0) {
-+ pr_err("%s: failed to register subsys\n", __func__);
-+ goto out;
-+ }
-+ pr_info("%s: OK\n", __func__);
-+out:
-+ return ret;
-+}
-+late_initcall(of_cfs_init);
projects / openwrt / openwrt.git / blobdiff