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Diffstat (limited to 'drivers/base/class.c')
-rw-r--r--drivers/base/class.c194
1 files changed, 180 insertions, 14 deletions
diff --git a/drivers/base/class.c b/drivers/base/class.c
index d2a2f8f2b4ed..479c12570881 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -16,6 +16,7 @@
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kdev_t.h>
+#include <linux/err.h>
#include "base.h"
#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
@@ -26,7 +27,7 @@ class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct class_attribute * class_attr = to_class_attr(attr);
struct class * dc = to_class(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (class_attr->show)
ret = class_attr->show(dc, buf);
@@ -39,7 +40,7 @@ class_attr_store(struct kobject * kobj, struct attribute * attr,
{
struct class_attribute * class_attr = to_class_attr(attr);
struct class * dc = to_class(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (class_attr->store)
ret = class_attr->store(dc, buf, count);
@@ -162,6 +163,69 @@ void class_unregister(struct class * cls)
subsystem_unregister(&cls->subsys);
}
+static void class_create_release(struct class *cls)
+{
+ kfree(cls);
+}
+
+static void class_device_create_release(struct class_device *class_dev)
+{
+ kfree(class_dev);
+}
+
+/**
+ * class_create - create a struct class structure
+ * @owner: pointer to the module that is to "own" this struct class
+ * @name: pointer to a string for the name of this class.
+ *
+ * This is used to create a struct class pointer that can then be used
+ * in calls to class_device_create().
+ *
+ * Note, the pointer created here is to be destroyed when finished by
+ * making a call to class_destroy().
+ */
+struct class *class_create(struct module *owner, char *name)
+{
+ struct class *cls;
+ int retval;
+
+ cls = kmalloc(sizeof(struct class), GFP_KERNEL);
+ if (!cls) {
+ retval = -ENOMEM;
+ goto error;
+ }
+ memset(cls, 0x00, sizeof(struct class));
+
+ cls->name = name;
+ cls->owner = owner;
+ cls->class_release = class_create_release;
+ cls->release = class_device_create_release;
+
+ retval = class_register(cls);
+ if (retval)
+ goto error;
+
+ return cls;
+
+error:
+ kfree(cls);
+ return ERR_PTR(retval);
+}
+
+/**
+ * class_destroy - destroys a struct class structure
+ * @cs: pointer to the struct class that is to be destroyed
+ *
+ * Note, the pointer to be destroyed must have been created with a call
+ * to class_create().
+ */
+void class_destroy(struct class *cls)
+{
+ if ((cls == NULL) || (IS_ERR(cls)))
+ return;
+
+ class_unregister(cls);
+}
/* Class Device Stuff */
@@ -262,7 +326,7 @@ static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
return 0;
}
-static char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
+static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
{
struct class_device *class_dev = to_class_dev(kobj);
@@ -375,7 +439,6 @@ static ssize_t show_dev(struct class_device *class_dev, char *buf)
{
return print_dev_t(buf, class_dev->devt);
}
-static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
void class_device_initialize(struct class_device *class_dev)
{
@@ -412,7 +475,31 @@ int class_device_add(struct class_device *class_dev)
if ((error = kobject_add(&class_dev->kobj)))
goto register_done;
- /* now take care of our own registration */
+ /* add the needed attributes to this device */
+ if (MAJOR(class_dev->devt)) {
+ struct class_device_attribute *attr;
+ attr = kmalloc(sizeof(*attr), GFP_KERNEL);
+ if (!attr) {
+ error = -ENOMEM;
+ kobject_del(&class_dev->kobj);
+ goto register_done;
+ }
+ memset(attr, sizeof(*attr), 0x00);
+ attr->attr.name = "dev";
+ attr->attr.mode = S_IRUGO;
+ attr->attr.owner = parent->owner;
+ attr->show = show_dev;
+ attr->store = NULL;
+ class_device_create_file(class_dev, attr);
+ class_dev->devt_attr = attr;
+ }
+
+ class_device_add_attrs(class_dev);
+ if (class_dev->dev)
+ sysfs_create_link(&class_dev->kobj,
+ &class_dev->dev->kobj, "device");
+
+ /* notify any interfaces this device is now here */
if (parent) {
down(&parent->sem);
list_add_tail(&class_dev->node, &parent->children);
@@ -421,16 +508,8 @@ int class_device_add(struct class_device *class_dev)
class_intf->add(class_dev);
up(&parent->sem);
}
-
- if (MAJOR(class_dev->devt))
- class_device_create_file(class_dev, &class_device_attr_dev);
-
- class_device_add_attrs(class_dev);
- if (class_dev->dev)
- sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->kobj, "device");
-
kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
+
register_done:
if (error && parent)
class_put(parent);
@@ -444,6 +523,58 @@ int class_device_register(struct class_device *class_dev)
return class_device_add(class_dev);
}
+/**
+ * class_device_create - creates a class device and registers it with sysfs
+ * @cs: pointer to the struct class that this device should be registered to.
+ * @dev: the dev_t for the char device to be added.
+ * @device: a pointer to a struct device that is assiociated with this class device.
+ * @fmt: string for the class device's name
+ *
+ * This function can be used by char device classes. A struct
+ * class_device will be created in sysfs, registered to the specified
+ * class. A "dev" file will be created, showing the dev_t for the
+ * device. The pointer to the struct class_device will be returned from
+ * the call. Any further sysfs files that might be required can be
+ * created using this pointer.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct class_device *class_device_create(struct class *cls, dev_t devt,
+ struct device *device, char *fmt, ...)
+{
+ va_list args;
+ struct class_device *class_dev = NULL;
+ int retval = -ENODEV;
+
+ if (cls == NULL || IS_ERR(cls))
+ goto error;
+
+ class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
+ if (!class_dev) {
+ retval = -ENOMEM;
+ goto error;
+ }
+ memset(class_dev, 0x00, sizeof(struct class_device));
+
+ class_dev->devt = devt;
+ class_dev->dev = device;
+ class_dev->class = cls;
+
+ va_start(args, fmt);
+ vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
+ va_end(args);
+ retval = class_device_register(class_dev);
+ if (retval)
+ goto error;
+
+ return class_dev;
+
+error:
+ kfree(class_dev);
+ return ERR_PTR(retval);
+}
+
void class_device_del(struct class_device *class_dev)
{
struct class * parent = class_dev->class;
@@ -460,6 +591,11 @@ void class_device_del(struct class_device *class_dev)
if (class_dev->dev)
sysfs_remove_link(&class_dev->kobj, "device");
+ if (class_dev->devt_attr) {
+ class_device_remove_file(class_dev, class_dev->devt_attr);
+ kfree(class_dev->devt_attr);
+ class_dev->devt_attr = NULL;
+ }
class_device_remove_attrs(class_dev);
kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
@@ -477,6 +613,32 @@ void class_device_unregister(struct class_device *class_dev)
class_device_put(class_dev);
}
+/**
+ * class_device_destroy - removes a class device that was created with class_device_create()
+ * @cls: the pointer to the struct class that this device was registered * with.
+ * @dev: the dev_t of the device that was previously registered.
+ *
+ * This call unregisters and cleans up a class device that was created with a
+ * call to class_device_create()
+ */
+void class_device_destroy(struct class *cls, dev_t devt)
+{
+ struct class_device *class_dev = NULL;
+ struct class_device *class_dev_tmp;
+
+ down(&cls->sem);
+ list_for_each_entry(class_dev_tmp, &cls->children, node) {
+ if (class_dev_tmp->devt == devt) {
+ class_dev = class_dev_tmp;
+ break;
+ }
+ }
+ up(&cls->sem);
+
+ if (class_dev)
+ class_device_unregister(class_dev);
+}
+
int class_device_rename(struct class_device *class_dev, char *new_name)
{
int error = 0;
@@ -576,6 +738,8 @@ EXPORT_SYMBOL_GPL(class_register);
EXPORT_SYMBOL_GPL(class_unregister);
EXPORT_SYMBOL_GPL(class_get);
EXPORT_SYMBOL_GPL(class_put);
+EXPORT_SYMBOL_GPL(class_create);
+EXPORT_SYMBOL_GPL(class_destroy);
EXPORT_SYMBOL_GPL(class_device_register);
EXPORT_SYMBOL_GPL(class_device_unregister);
@@ -584,6 +748,8 @@ EXPORT_SYMBOL_GPL(class_device_add);
EXPORT_SYMBOL_GPL(class_device_del);
EXPORT_SYMBOL_GPL(class_device_get);
EXPORT_SYMBOL_GPL(class_device_put);
+EXPORT_SYMBOL_GPL(class_device_create);
+EXPORT_SYMBOL_GPL(class_device_destroy);
EXPORT_SYMBOL_GPL(class_device_create_file);
EXPORT_SYMBOL_GPL(class_device_remove_file);
EXPORT_SYMBOL_GPL(class_device_create_bin_file);