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/*
* drm_sysfs.c - Modifications to drm_sysfs_class.c to support
* extra sysfs attribute from DRM. Normal drm_sysfs_class
* does not allow adding attributes.
*
* Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
* Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2003-2004 IBM Corp.
*
* This file is released under the GPLv2
*
*/
#include <linux/config.h>
#include <linux/device.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include "drm_core.h"
struct drm_sysfs_class {
struct class_device_attribute attr;
struct class class;
};
#define to_drm_sysfs_class(d) container_of(d, struct drm_sysfs_class, class)
struct simple_dev {
struct list_head node;
dev_t dev;
struct class_device class_dev;
};
#define to_simple_dev(d) container_of(d, struct simple_dev, class_dev)
static LIST_HEAD(simple_dev_list);
static DEFINE_SPINLOCK(simple_dev_list_lock);
static void release_simple_dev(struct class_device *class_dev)
{
struct simple_dev *s_dev = to_simple_dev(class_dev);
kfree(s_dev);
}
static ssize_t show_dev(struct class_device *class_dev, char *buf)
{
struct simple_dev *s_dev = to_simple_dev(class_dev);
return print_dev_t(buf, s_dev->dev);
}
static void drm_sysfs_class_release(struct class *class)
{
struct drm_sysfs_class *cs = to_drm_sysfs_class(class);
kfree(cs);
}
/* Display the version of drm_core. This doesn't work right in current design */
static ssize_t version_show(struct class *dev, char *buf)
{
return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
}
static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
/**
* drm_sysfs_create - create a struct drm_sysfs_class structure
* @owner: pointer to the module that is to "own" this struct drm_sysfs_class
* @name: pointer to a string for the name of this class.
*
* This is used to create a struct drm_sysfs_class pointer that can then be used
* in calls to drm_sysfs_device_add().
*
* Note, the pointer created here is to be destroyed when finished by making a
* call to drm_sysfs_destroy().
*/
struct drm_sysfs_class *drm_sysfs_create(struct module *owner, char *name)
{
struct drm_sysfs_class *cs;
int retval;
cs = kmalloc(sizeof(*cs), GFP_KERNEL);
if (!cs) {
retval = -ENOMEM;
goto error;
}
memset(cs, 0x00, sizeof(*cs));
cs->class.name = name;
cs->class.class_release = drm_sysfs_class_release;
cs->class.release = release_simple_dev;
cs->attr.attr.name = "dev";
cs->attr.attr.mode = S_IRUGO;
cs->attr.attr.owner = owner;
cs->attr.show = show_dev;
cs->attr.store = NULL;
retval = class_register(&cs->class);
if (retval)
goto error;
class_create_file(&cs->class, &class_attr_version);
return cs;
error:
kfree(cs);
return ERR_PTR(retval);
}
/**
* drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
* @cs: pointer to the struct drm_sysfs_class that is to be destroyed
*
* Note, the pointer to be destroyed must have been created with a call to
* drm_sysfs_create().
*/
void drm_sysfs_destroy(struct drm_sysfs_class *cs)
{
if ((cs == NULL) || (IS_ERR(cs)))
return;
class_unregister(&cs->class);
}
/**
* drm_sysfs_device_add - adds a class device to sysfs for a character driver
* @cs: pointer to the struct drm_sysfs_class that this device should be registered to.
* @dev: the dev_t for the 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
*
* 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 drm_sysfs_class passed to this function must have previously been
* created with a call to drm_sysfs_create().
*/
struct class_device *drm_sysfs_device_add(struct drm_sysfs_class *cs, dev_t dev,
struct device *device,
const char *fmt, ...)
{
va_list args;
struct simple_dev *s_dev = NULL;
int retval;
if ((cs == NULL) || (IS_ERR(cs))) {
retval = -ENODEV;
goto error;
}
s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL);
if (!s_dev) {
retval = -ENOMEM;
goto error;
}
memset(s_dev, 0x00, sizeof(*s_dev));
s_dev->dev = dev;
s_dev->class_dev.dev = device;
s_dev->class_dev.class = &cs->class;
va_start(args, fmt);
vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args);
va_end(args);
retval = class_device_register(&s_dev->class_dev);
if (retval)
goto error;
class_device_create_file(&s_dev->class_dev, &cs->attr);
spin_lock(&simple_dev_list_lock);
list_add(&s_dev->node, &simple_dev_list);
spin_unlock(&simple_dev_list_lock);
return &s_dev->class_dev;
error:
kfree(s_dev);
return ERR_PTR(retval);
}
/**
* drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
* @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 drm_sysfs_device_add()
*/
void drm_sysfs_device_remove(dev_t dev)
{
struct simple_dev *s_dev = NULL;
int found = 0;
spin_lock(&simple_dev_list_lock);
list_for_each_entry(s_dev, &simple_dev_list, node) {
if (s_dev->dev == dev) {
found = 1;
break;
}
}
if (found) {
list_del(&s_dev->node);
spin_unlock(&simple_dev_list_lock);
class_device_unregister(&s_dev->class_dev);
} else {
spin_unlock(&simple_dev_list_lock);
}
}
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