kernel-ark/drivers/char/drm/drm_sysfs.c
Jeff Garzik 24f73c92a9 drm: fix error returns, sysfs error handling
- callers of drm_sysfs_create() and drm_sysfs_device_add() looked for
  errors using IS_ERR(), but the functions themselves only ever returned
  NULL on error.  Fixed.

- unwind from, and propagate sysfs errors

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
2006-10-25 09:40:40 -07:00

157 lines
4.4 KiB
C

/*
* 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/device.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include "drm_core.h"
#include "drmP.h"
/* 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 class *drm_sysfs_create(struct module *owner, char *name)
{
struct class *class;
int err;
class = class_create(owner, name);
if (!class) {
err = -ENOMEM;
goto err_out;
}
err = class_create_file(class, &class_attr_version);
if (err)
goto err_out_class;
return class;
err_out_class:
class_destroy(class);
err_out:
return ERR_PTR(err);
}
/**
* 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 class *class)
{
if ((class == NULL) || (IS_ERR(class)))
return;
class_remove_file(class, &class_attr_version);
class_destroy(class);
}
static ssize_t show_dri(struct class_device *class_device, char *buf)
{
drm_device_t * dev = ((drm_head_t *)class_get_devdata(class_device))->dev;
if (dev->driver->dri_library_name)
return dev->driver->dri_library_name(dev, buf);
return snprintf(buf, PAGE_SIZE, "%s\n", dev->driver->pci_driver.name);
}
static struct class_device_attribute class_device_attrs[] = {
__ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
};
/**
* drm_sysfs_device_add - adds a class device to sysfs for a character driver
* @cs: pointer to the struct 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 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 class *cs, drm_head_t *head)
{
struct class_device *class_dev;
int i, j, err;
class_dev = class_device_create(cs, NULL,
MKDEV(DRM_MAJOR, head->minor),
&(head->dev->pdev)->dev,
"card%d", head->minor);
if (!class_dev) {
err = -ENOMEM;
goto err_out;
}
class_set_devdata(class_dev, head);
for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++) {
err = class_device_create_file(class_dev,
&class_device_attrs[i]);
if (err)
goto err_out_files;
}
return class_dev;
err_out_files:
if (i > 0)
for (j = 0; j < i; j++)
class_device_remove_file(class_dev,
&class_device_attrs[i]);
class_device_unregister(class_dev);
err_out:
return ERR_PTR(err);
}
/**
* 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(struct class_device *class_dev)
{
int i;
for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
class_device_remove_file(class_dev, &class_device_attrs[i]);
class_device_unregister(class_dev);
}