[permalink] [raw]

Subject: [patch 8/8] input: rename input_dev_class to input_class to be correct.

From: Greg Kroah-Hartman <[email protected]>

Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
drivers/input/evdev.c | 4 ++--
drivers/input/input.c | 14 +++++++-------
drivers/input/joydev.c | 4 ++--
drivers/input/mousedev.c | 8 ++++----
drivers/input/tsdev.c | 4 ++--
include/linux/input.h | 2 +-
6 files changed, 18 insertions(+), 18 deletions(-)

--- gregkh-2.6.orig/drivers/input/evdev.c
+++ gregkh-2.6/drivers/input/evdev.c
@@ -686,7 +686,7 @@ static struct input_handle *evdev_connec

evdev_table[minor] = evdev;

- class_device_create(&input_dev_class, &dev->cdev,
+ class_device_create(&input_class, &dev->cdev,
MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
dev->cdev.dev, "event%d", minor);

@@ -698,7 +698,7 @@ static void evdev_disconnect(struct inpu
struct evdev *evdev = handle->private;
struct evdev_list *list;

- class_device_destroy(&input_dev_class,
+ class_device_destroy(&input_class,
MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
evdev->exist = 0;

--- gregkh-2.6.orig/drivers/input/input.c
+++ gregkh-2.6/drivers/input/input.c
@@ -39,7 +39,7 @@ EXPORT_SYMBOL(input_close_device);
EXPORT_SYMBOL(input_accept_process);
EXPORT_SYMBOL(input_flush_device);
EXPORT_SYMBOL(input_event);
-EXPORT_SYMBOL_GPL(input_dev_class);
+EXPORT_SYMBOL_GPL(input_class);

#define INPUT_DEVICES 256

@@ -724,8 +724,8 @@ static void input_dev_release(struct cla
module_put(THIS_MODULE);
}

-struct class input_dev_class = {
- .name = "input_dev",
+struct class input_class = {
+ .name = "input",
.release = input_dev_release,
.class_dev_attrs = input_dev_attrs,
};
@@ -737,7 +737,7 @@ struct input_dev *input_allocate_device(
dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
if (dev) {
dev->dynalloc = 1;
- dev->cdev.class = &input_dev_class;
+ dev->cdev.class = &input_class;
class_device_initialize(&dev->cdev);
INIT_LIST_HEAD(&dev->h_list);
INIT_LIST_HEAD(&dev->node);
@@ -925,7 +925,7 @@ static int __init input_init(void)
{
int err;

- err = class_register(&input_dev_class);
+ err = class_register(&input_class);
if (err) {
printk(KERN_ERR "input: unable to register input_dev class\n");
return err;
@@ -944,7 +944,7 @@ static int __init input_init(void)
return 0;

fail2: input_proc_exit();
- fail1: class_unregister(&input_dev_class);
+ fail1: class_unregister(&input_class);
return err;
}

@@ -952,7 +952,7 @@ static void __exit input_exit(void)
{
input_proc_exit();
unregister_chrdev(INPUT_MAJOR, "input");
- class_unregister(&input_dev_class);
+ class_unregister(&input_class);
}

subsys_initcall(input_init);
--- gregkh-2.6.orig/drivers/input/joydev.c
+++ gregkh-2.6/drivers/input/joydev.c
@@ -513,7 +513,7 @@ static struct input_handle *joydev_conne

joydev_table[minor] = joydev;

- class_device_create(&input_dev_class, &dev->cdev,
+ class_device_create(&input_class, &dev->cdev,
MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor),
dev->cdev.dev, "js%d", minor);

@@ -525,7 +525,7 @@ static void joydev_disconnect(struct inp
struct joydev *joydev = handle->private;
struct joydev_list *list;

- class_device_destroy(&input_dev_class, MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + joydev->minor));
+ class_device_destroy(&input_class, MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + joydev->minor));
joydev->exist = 0;

if (joydev->open) {
--- gregkh-2.6.orig/drivers/input/mousedev.c
+++ gregkh-2.6/drivers/input/mousedev.c
@@ -648,7 +648,7 @@ static struct input_handle *mousedev_con

mousedev_table[minor] = mousedev;

- class_device_create(&input_dev_class, &dev->cdev,
+ class_device_create(&input_class, &dev->cdev,
MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor),
dev->cdev.dev, "mouse%d", minor);

@@ -660,7 +660,7 @@ static void mousedev_disconnect(struct i
struct mousedev *mousedev = handle->private;
struct mousedev_list *list;

- class_device_destroy(&input_dev_class,
+ class_device_destroy(&input_class,
MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + mousedev->minor));
mousedev->exist = 0;

@@ -734,7 +734,7 @@ static int __init mousedev_init(void)
mousedev_mix.exist = 1;
mousedev_mix.minor = MOUSEDEV_MIX;

- class_device_create(&input_dev_class, NULL,
+ class_device_create(&input_class, NULL,
MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + MOUSEDEV_MIX), NULL, "mice");

#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
@@ -753,7 +753,7 @@ static void __exit mousedev_exit(void)
if (psaux_registered)
misc_deregister(&psaux_mouse);
#endif
- class_device_destroy(&input_dev_class,
+ class_device_destroy(&input_class,
MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + MOUSEDEV_MIX));
input_unregister_handler(&mousedev_handler);
}
--- gregkh-2.6.orig/drivers/input/tsdev.c
+++ gregkh-2.6/drivers/input/tsdev.c
@@ -409,7 +409,7 @@ static struct input_handle *tsdev_connec

tsdev_table[minor] = tsdev;

- class_device_create(&input_dev_class, &dev->cdev,
+ class_device_create(&input_class, &dev->cdev,
MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
dev->cdev.dev, "ts%d", minor);

@@ -421,7 +421,7 @@ static void tsdev_disconnect(struct inpu
struct tsdev *tsdev = handle->private;
struct tsdev_list *list;

- class_device_destroy(&input_dev_class,
+ class_device_destroy(&input_class,
MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
tsdev->exist = 0;

--- gregkh-2.6.orig/include/linux/input.h
+++ gregkh-2.6/include/linux/input.h
@@ -1074,7 +1074,7 @@ static inline void input_set_abs_params(
dev->absbit[LONG(axis)] |= BIT(axis);
}

-extern struct class input_dev_class;
+extern struct class input_class;

#endif
#endif

--

2005-10-13 02:12:57

by Greg KH

[permalink] [raw]

Subject: [patch 3/8] Driver Core: document struct class_device properly

From: Greg Kroah-Hartman <[email protected]>

Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
include/linux/device.h | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

--- gregkh-2.6.orig/include/linux/device.h
+++ gregkh-2.6/include/linux/device.h
@@ -203,6 +203,30 @@ struct class_device_attribute class_devi
extern int class_device_create_file(struct class_device *,
const struct class_device_attribute *);

+/**
+ * struct class_device - class devices
+ * @class: pointer to the parent class for this class device. This is required.
+ * @devt: for internal use by the driver core only.
+ * @node: for internal use by the driver core only.
+ * @kobj: for internal use by the driver core only.
+ * @devt_attr: for internal use by the driver core only.
+ * @dev: if set, a symlink to the struct device is created in the sysfs
+ * directory for this struct class device.
+ * @class_data: pointer to whatever you want to store here for this struct
+ * class_device. Use class_get_devdata() and class_set_devdata() to get and
+ * set this pointer.
+ * @parent: pointer to a struct class_device that is the parent of this struct
+ * class_device. If NULL, this class_device will show up at the root of the
+ * struct class in sysfs (which is probably what you want to have happen.)
+ * @release: pointer to a release function for this struct class_device. If
+ * set, this will be called instead of the class specific release function.
+ * Only use this if you want to override the default release function, like
+ * when you are nesting class_device structures.
+ * @hotplug: pointer to a hotplug function for this struct class_device. If
+ * set, this will be called instead of the class specific hotplug function.
+ * Only use this if you want to override the default hotplug function, like
+ * when you are nesting class_device structures.
+ */
struct class_device {
struct list_head node;

--

2005-10-13 06:38:42

by Vojtech Pavlik

[permalink] [raw]

2005-10-18 15:41:59

by Dmitry Torokhov

[permalink] [raw]

Subject: Re: [patch 0/8] Nesting class_device patches that actually work

On 10/18/05, Kay Sievers <[email protected]> wrote:
> On Tue, Oct 18, 2005 at 03:18:22AM -0400, Adam Belay wrote:
> > On Mon, Oct 17, 2005 at 10:26:17PM -0700, Greg KH wrote:
> > > On Mon, Oct 17, 2005 at 07:24:30PM -0400, Adam Belay wrote:
> > > >
> > > > Sounds good to me. The changes to driver model internals may be substantial.
> > > > For example, because buses and classes will share more code, it's
> > > > reasonable to allow drivers to bind to any "device" object, even class
> > > > devices. Of course this would be limited to classes that choose to
> > > > implement driver matching etc. We are doing this now with the pci express
> > > > port driver.
> > >
> > > That's a bus, not a class device. Drivers bind to devices through a
> > > bus. That's why we have busses.
> >
> > If class devices and devices belong in the same tree, then clearly the original
> > distinction is artificial. "struct bus_type" is a class of "struct device".
> > "struct class" is a class of "struct class_dev". We now know of devices
> > in between these two extremes (e.g. pci express port driver). It's also
> > possible that drivers will want to bind to class devices (e.g. a partition
> > driver binding to a block device). Isn't it fair to say that the "bus_type"
> > vs. "class" distinction is also artificial? At the very least they are
> > duplicating some code.
>
> I agree and would like to see the "bus" functionality just as set of special
> methods of a unified device struture also used for class devices.
>
> > > > > Oh, one tiny problem. "virtual devices" are not currently represented
> > > > > in our device tree, but are in the class tree. Things like the
> > > > > different vc and ttys and misc devices are examples of this. I'll just
> > > > > put them on the "platform" bus if no one minds.
> > > >
> > > > I think we should be trying to kill off the platform bus (it's artifical and
> > > > doesn't show the real relationships between these devices). Instead, just
> > > > hang them off the root of the tree.
> > >
> > > Everything that's currently a platform device go to the root? No,
> > > that's not going to happen, sorry.
>
> But will sticking stuff like "mice" or "tty" into "platform" will really
> work? These devices belong to their own primary class like "input" or "tty" and
> they can not be part of a "bus" at the same time, right?
>
> I'm dreaming of:
> - merging "struct device" and "struct class_device"
>
> - provide current "bus" and "class" methodes for _all_ devices
>

This way you are fattening object interface and I don't think it is a
good thing. While we may want to have sysfs representation of all
devices be in /sys/devices internally we should keep the interfaces
and implementation clean and do not turn it into a kitchen sink.

--
Dmitry

2005-10-18 16:53:32

by Greg KH

[permalink] [raw]

Subject: Re: [patch 0/8] Nesting class_device patches that actually work

On Tue, Oct 18, 2005 at 03:18:22AM -0400, Adam Belay wrote:
> On Mon, Oct 17, 2005 at 10:26:17PM -0700, Greg KH wrote:
> > On Mon, Oct 17, 2005 at 07:24:30PM -0400, Adam Belay wrote:
> > >
> > > Sounds good to me. The changes to driver model internals may be substantial.
> > > For example, because buses and classes will share more code, it's
> > > reasonable to allow drivers to bind to any "device" object, even class
> > > devices. Of course this would be limited to classes that choose to
> > > implement driver matching etc. We are doing this now with the pci express
> > > port driver.
> >
> > That's a bus, not a class device. Drivers bind to devices through a
> > bus. That's why we have busses.
>
> If class devices and devices belong in the same tree, then clearly the original
> distinction is artificial. "struct bus_type" is a class of "struct device".

Huh? "struct bus_type" has a list of "struct device" and "struct
drivers" that it knows about. I don't understand your use of the word
"class" in this sentance. (yeah, it's a horribly overloaded term,
sorry...)

> "struct class" is a class of "struct class_dev". We now know of devices
> in between these two extremes (e.g. pci express port driver).

pci express is just fine, I don't know why you don't like it :)

It's a bus, with different types of devices on it, and different types
of drivers that bind to those devices. That's it.

> It's also possible that drivers will want to bind to class devices
> (e.g. a partition driver binding to a block device).

Almost. Classes like input and video might want to do something like
that. But that's something for the future.

> Isn't it fair to say that the "bus_type" vs. "class" distinction is
> also artificial? At the very least they are duplicating some code.

No, they are very different. busses do some work (matches drivers to
devices and other bus specific glue). Classes are just a grouping of a
function of a device (input, tty, misc, etc.)

> > > Also, we could make driver objects a "class" and represent them in the
> > > global device tree, giving each driver instance its own unique namespace.
> >
> > Huh? How would you do that? Also, we really don't have different
> > driver "instances", so trying to represent something like that in sysfs
> > would probably be more work than it's worth.
>
> (all in same tree)
> pci0000:00.00 <- physical device
> |
> \- e1000:0 <- driver
> |
> \- eth0 <- class device
>
> We already informally have driver instances. They're pointed to in
> "driver_data".

That's merely a blob of data the driver needs to use. To call that a
full blown "instance" is pretty gracious. I think that trying to turn
that blob into a sysfs representation would require modifying every
driver in the kernel tree in a non-simple manner. That's something that
I don't want to undertake at all. But if you can show me otherwise...
:)

You are treating the driver in your above tree as a "bridge" between the
physical device and the class device. I don't think we really need to
show that in our tree, as it's an artificial thing.

> > > > Oh, one tiny problem. "virtual devices" are not currently represented
> > > > in our device tree, but are in the class tree. Things like the
> > > > different vc and ttys and misc devices are examples of this. I'll just
> > > > put them on the "platform" bus if no one minds.
> > >
> > > I think we should be trying to kill off the platform bus (it's artifical and
> > > doesn't show the real relationships between these devices). Instead, just
> > > hang them off the root of the tree.
> >
> > Everything that's currently a platform device go to the root? No,
> > that's not going to happen, sorry.
>
> Not at all. Rather, everything that's currently a platform device goes to
> where it actually belongs in the device tree. ACPI (and other firmware)
> enumerates all of these devices. They're generally children of LPCs and
> ISA bridges.

Not on embedded devices. Systems-on-a-chip have no "busses" generally.

> Making a special exception for these devices is ugly when we can
> easily represent them like every other device. This will even be
> possible without ACPI for many of these devices if we create an "ISA"
> bus driver abstraction.

Yes, if you have a ISA and a "system" bus. But then the "platform" bus
just goes back to being the system one. And you are where you
started...

> The main point here is that "platform" is really a hack to represent primitive
> physical devices that don't fit well into the driver model. There may be
> better ways of approaching this problem.

If you have a better approach, I would be glad to see it. And I don't
think it's a "hack" as lots of systems only use that bus.

> > > If the device doesn't have any parents or dependencies, then that's
> > > logically where it belongs.
> >
> > We do have a real platform "bus" that devices hang off of. Where else
> > is that keyboard controller at :)
>
> As stated above, the keyboard actually does have a real location to hang off of.
> Nonetheless, a keyboard controller is a physical device. It's very different
> from a "virtual device" like a tty. Therefore, it seems unreasonable to make
> virtual devices belong to the "platform" bus.

Then where should virtual devices belong?

> If a device doesn't have a parent device, it belongs at the root of the tree.
> That's the only obvious way to represent such a lack of dependency. This
> applies to both class and physical devices.

You want to put 512 tty class devices in /sys/devices/ ? I don't want
to see that.

thanks,

greg k-h

2005-12-01 19:00:06

by Patrick Mochel

[permalink] [raw]

Subject: Re: [patch 0/8] Nesting class_device patches that actually work

[ Uhh, sorry about the very long delay in responding to this. I was off
the continent and unemployed at the time. Both of those problems are
solved now. :) ]

On Fri, 14 Oct 2005, Kay Sievers wrote:

> On Thu, Oct 13, 2005 at 04:35:25PM -0500, Dmitry Torokhov wrote:
> > On 10/13/05, Kay Sievers <[email protected]> wrote:
> > >
> > > The nesting classes implement a fraction of a device hierarchy in
> > > /sys/class. It moves arbitrary relation information into the class
> > > directory, where nothing else than device classification belongs.
> > > What is the rationale behind sticking device trees into class?
> > >
> > > Instead of that, I propose a unification of "/sys/devices-devices"
> > > and "class-devices". The differentiation of both does not make sense
> > > in a wold where we can't really tell if a device is hardware or virtual.
> > >
> > > We should model _all_ devices with its actual realationship in
> > > /sys/devices and /sys/class should only be a pinter to the actual
> > > devices in that place. Device like "mice", which have no parent, would
> > > sit at the top level of /sys/devices. All devices in /sys/class are
> > > only symlinks and never devices by itself.
> > > That way userspace can read all device relation at _one_ place in a sane
> > > way, and we keep the clean class interface to have easy access to all
> > > devices of a specific group.
> > > It gives us the right abstraction and is future proof, cause
> > > the class interface will not change when the relation between devices
> > > changes. The destinction between classes and buses would no longer be
> > > needed, and as we see in the "input" case never made sense anyway.
> > >
> > > /sys/class/block would look exactly like /sys/block today. The only
> > > difference is that there are symlinks to follow instead of class devices
> > > on its own. With every device creation we will get the whole dependency
> > > path of the device in the DEVPATH and a "classsification symlink" in
> > > /sys/class. The input devices are all clearly modeled in its hierarchy,
> > > in /sys/devices but we also get clean class interfaces:
> > >
> >
> > Kay eased my task by enumerating all issues I have with Greg's
> > approach. Not all the world is udev and not all class devices have
> > "/dev" represetation so haveing one program being able to understand
> > new sysfs hierarchy is not enough IHMO.
> >
> > However I do not think that "moving" class devices into /sys/devices
> > hierarchy is the right solution either because one physical device
> > could easily end up belonging to several classes.
>
> Sure, than that physical (while that distinction is silly by itself)
> will just have several child devices. Look at the mouse0 and event0 in
> the ascii drawing.
>
> > I recenty got an
> > e-mail from Adam Belay (whom I am pulling into the discussion)
> > regarding his desire to rearrange net/wireless representation. I think
> > it would be quite natural to have /sys/class/net/interfaces and
> > /sys/class/net/wireless /sys/class/net/irda, and /sys/class/net/wired
> > subclasses where "interfaces" would enumerate _all_ network interfaces
> > in the system, and the rest would show only devices of their class.
>
> That solution would keep a better device separation, sure. But it
> is completely incompatible with everything we ever had in sysfs and
> nobody wants to rewrite _all_ userspace programs.
>
> It invents artificial subclass names below a "master" class, which
> is absolutely not needed.
>
> It creates the magic "interfaces" directory, which is confusing, cause
> it classifies devices by itself.
>
> It doesn't represent any relationship and hierarchy of devices and
> adding a forest of magic symlinks and "device" pointers is a very
> bad design. The proposed "inter-class" symlinks make it even harder
> to understand sysfs as it already is.
>
> The biggest problem with current sysfs is that the driver hacker has to
> decide if the device is "hardware" or "virtual" which in a lot of
> cases just can't tell and this distiction doesn't make any sense today.

Could you provide an example of this? The driver model is currently
designed to handle two basic types of objects:

- Physical objects (mapping to struct device) that are discovered by a bus
driver's probing/scanning routines.

- Logical objects (mapping to struct class_device) that are created when a
driver binds to a device and registers with the device class that the
driver belongs to.

Most of that should happen behind the scenes in the bus and class code
respectively.

> All the more complex subsystems use "virtual buses" and an unconnected
> bunch of class-devices to model its sysfs represention, which is just
> to work around a major design flaw in sysfs!

I wouldn't call this a design flaw. This was just willingness in the
implementors of those subsystems to overload the current design features,
and unwillingness to add new infrastructure that better represented what
they wanted to do. Don't blame the driver model for this; it was more a
lack of time and/or understanding of what needed to be done.

Note this is exactly why /sys/block exists, and even why kobjects were
created - someone wanted to export things that weren't currently
represented, so they overloaded the existing structures, and did so in a
fairly nasty way.

> We really should get _one_ device tree with its natural hierarchy, get
> rid of the stupid "device"-link, the PHYSDEVPATH and the unconnected
> class devices. Every device should just carry its dependency tree in
> it _own_ devpath!
>
> I'm very sure, we want a unified tree in /sys/devices, regardless of the type
> of device, to represent the global hierarchy wich is exactly what you want to
> know from a device tree!
> That way we stack "virtual" _and_ "physical" in a sane manner and at the same
> time get very clean class interfaces. We would stop to mix up "hierarchy" and
> "classes" all over the tree.

For what purpose? To make udev easier to program? Or, to make it easier to
determine what attributes are located where? Or, to determine what devices
map to what class devices? (Really, I'm curious).

Recall tht sysfs is designed to export kernel objects in a natural
manner. What we have now is mostly natural. There are some artificial bits
to it (the most agregious are things like usb-serial), but the distinction
between physical devices and class devices and their relationships with
drivers and the buses that they're on is clearly spelled out.

So what if there is a forest of symlinks?

If you want a unified representation of every thing (objects and
attrributes) that represent a single piece of hardware (i.e. in a compact,
single screen full of text), then that should be done in userspace, IMHO.
:)

Thanks,

Pat