[PATCH] Use attribute groups in struct device_type

From: Dmitry Torokhov
Date: Sat Mar 10 2007 - 01:37:56 EST

Greg,

Please consider applying the patch below. It switches struct device_type
to using attribute groups which os more flexible. I am using it in my
input class_device -> device conversion (which is 99% done btw).

I looked through -mm and the latest git and there does not seem to be
any users of struct device_type yet...

--
Dmitry

Driver core: use attribute groups in struct device_type

Attribute groups are more flexible than attribute lists
(an attribute list can be represented by anonymous group)
so switch struct device_type to use them.

Also rework attribute creation for devices so that they all
cleaned up properly in case of errors.

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
---

drivers/base/core.c | 115 +++++++++++++++++++++++++++++--------------------
include/linux/device.h | 2
2 files changed, 70 insertions(+), 47 deletions(-)

Index: work/drivers/base/core.c
===================================================================
--- work.orig/drivers/base/core.c
+++ work/drivers/base/core.c
@@ -259,64 +259,95 @@ static ssize_t store_uevent(struct devic
return count;
}

-static int device_add_groups(struct device *dev)
+static int device_add_attributes(struct device *dev,
+ struct device_attribute *attrs)
+{
+ int error = 0;
+ int i;
+
+ if (attrs) {
+ for (i = 0; attr_name(attrs[i]); i++) {
+ error = device_create_file(dev, &attrs[i]);
+ if (error)
+ break;
+ }
+ if (error)
+ while (--i >= 0)
+ device_remove_file(dev, &attrs[i]);
+ }
+ return error;
+}
+
+static void device_remove_attributes(struct device *dev,
+ struct device_attribute *attrs)
{
int i;
+
+ if (attrs)
+ for (i = 0; attr_name(attrs[i]); i++)
+ device_remove_file(dev, &attrs[i]);
+}
+
+static int device_add_groups(struct device *dev,
+ struct attribute_group **groups)
+{
int error = 0;
+ int i;

- if (dev->groups) {
- for (i = 0; dev->groups[i]; i++) {
- error = sysfs_create_group(&dev->kobj, dev->groups[i]);
+ if (groups) {
+ for (i = 0; groups[i]; i++) {
+ error = sysfs_create_group(&dev->kobj, groups[i]);
if (error) {
while (--i >= 0)
- sysfs_remove_group(&dev->kobj, dev->groups[i]);
- goto out;
+ sysfs_remove_group(&dev->kobj, groups[i]);
+ break;
}
}
}
-out:
return error;
}

-static void device_remove_groups(struct device *dev)
+static void device_remove_groups(struct device *dev,
+ struct attribute_group **groups)
{
int i;
- if (dev->groups) {
- for (i = 0; dev->groups[i]; i++) {
- sysfs_remove_group(&dev->kobj, dev->groups[i]);
- }
- }
+
+ if (groups)
+ for (i = 0; groups[i]; i++)
+ sysfs_remove_group(&dev->kobj, groups[i]);
}

static int device_add_attrs(struct device *dev)
{
struct class *class = dev->class;
struct device_type *type = dev->type;
- int error = 0;
- int i;
+ int error;

- if (class && class->dev_attrs) {
- for (i = 0; attr_name(class->dev_attrs[i]); i++) {
- error = device_create_file(dev, &class->dev_attrs[i]);
- if (error)
- break;
- }
+ if (class) {
+ error = device_add_attributes(dev, class->dev_attrs);
if (error)
- while (--i >= 0)
- device_remove_file(dev, &class->dev_attrs[i]);
+ return error;
}

- if (type && type->attrs) {
- for (i = 0; attr_name(type->attrs[i]); i++) {
- error = device_create_file(dev, &type->attrs[i]);
- if (error)
- break;
- }
+ if (type) {
+ error = device_add_groups(dev, type->groups);
if (error)
- while (--i >= 0)
- device_remove_file(dev, &type->attrs[i]);
+ goto err_remove_class_attrs;
}

+ error = device_add_groups(dev, dev->groups);
+ if (error)
+ goto err_remove_type_groups;
+
+ return 0;
+
+ err_remove_type_groups:
+ if (type)
+ device_remove_groups(dev, type->groups);
+ err_remove_class_attrs:
+ if (class)
+ device_remove_attributes(dev, class->dev_attrs);
+
return error;
}

@@ -324,17 +355,14 @@ static void device_remove_attrs(struct d
{
struct class *class = dev->class;
struct device_type *type = dev->type;
- int i;

- if (class && class->dev_attrs) {
- for (i = 0; attr_name(class->dev_attrs[i]); i++)
- device_remove_file(dev, &class->dev_attrs[i]);
- }
+ device_remove_groups(dev, dev->groups);

- if (type && type->attrs) {
- for (i = 0; attr_name(type->attrs[i]); i++)
- device_remove_file(dev, &type->attrs[i]);
- }
+ if (type)
+ device_remove_groups(dev, type->groups);
+
+ if (class)
+ device_remove_attributes(dev, class->dev_attrs);
}


@@ -599,8 +627,6 @@ int device_add(struct device *dev)

if ((error = device_add_attrs(dev)))
goto AttrsError;
- if ((error = device_add_groups(dev)))
- goto GroupError;
if ((error = device_pm_add(dev)))
goto PMError;
if ((error = bus_add_device(dev)))
@@ -624,7 +650,7 @@ int device_add(struct device *dev)
up(&dev->class->sem);
}
Done:
- kfree(class_name);
+ kfree(class_name);
put_device(dev);
return error;
AttachError:
@@ -635,8 +661,6 @@ int device_add(struct device *dev)
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
- device_remove_groups(dev);
- GroupError:
device_remove_attrs(dev);
AttrsError:
if (dev->devt_attr) {
@@ -783,7 +807,6 @@ void device_del(struct device * dev)
up(&dev->class->sem);
}
device_remove_file(dev, &dev->uevent_attr);
- device_remove_groups(dev);
device_remove_attrs(dev);
bus_remove_device(dev);

Index: work/include/linux/device.h
===================================================================
--- work.orig/include/linux/device.h
+++ work/include/linux/device.h
@@ -328,7 +328,7 @@ extern struct class_device *class_device
extern void class_device_destroy(struct class *cls, dev_t devt);

struct device_type {
- struct device_attribute *attrs;
+ struct attribute_group **groups;
int (*uevent)(struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size);
void (*release)(struct device *dev);
-
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