drivers/char/drm/drm_sysfs.c

   1
   2 /*
   3  * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
   4  *               extra sysfs attribute from DRM. Normal drm_sysfs_class
   5  *               does not allow adding attributes.
   6  *
   7  * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
   8  * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
   9  * Copyright (c) 2003-2004 IBM Corp.
  10  *
  11  * This file is released under the GPLv2
  12  *
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/err.h>
  18
  19 #include "drm_core.h"
  20 #include "drmP.h"
  21
  22 /* Display the version of drm_core. This doesn't work right in current design */
  23 static ssize_t version_show(struct class *dev, char *buf)
  24 {
  25         return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
  26                        CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
  27 }
  28
  29 static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
  30
  31 /**
  32  * drm_sysfs_create - create a struct drm_sysfs_class structure
  33  * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
  34  * @name: pointer to a string for the name of this class.
  35  *
  36  * This is used to create a struct drm_sysfs_class pointer that can then be used
  37  * in calls to drm_sysfs_device_add().
  38  *
  39  * Note, the pointer created here is to be destroyed when finished by making a
  40  * call to drm_sysfs_destroy().
  41  */
  42 struct class *drm_sysfs_create(struct module *owner, char *name)
  43 {
  44         struct class *class;
  45
  46         class = class_create(owner, name);
  47         if (!class)
  48                 return class;
  49
  50         class_create_file(class, &class_attr_version);
  51         return class;
  52 }
  53
  54 /**
  55  * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
  56  * @cs: pointer to the struct drm_sysfs_class that is to be destroyed
  57  *
  58  * Note, the pointer to be destroyed must have been created with a call to
  59  * drm_sysfs_create().
  60  */
  61 void drm_sysfs_destroy(struct class *class)
  62 {
  63         if ((class == NULL) || (IS_ERR(class)))
  64                 return;
  65
  66         class_remove_file(class, &class_attr_version);
  67         class_destroy(class);
  68 }
  69
  70 static ssize_t show_dri(struct class_device *class_device, char *buf)
  71 {
  72         drm_device_t * dev = ((drm_head_t *)class_get_devdata(class_device))->dev;
  73         if (dev->driver->dri_library_name)
  74                 return dev->driver->dri_library_name(dev, buf);
  75         return snprintf(buf, PAGE_SIZE, "%s\n", dev->driver->pci_driver.name);
  76 }
  77
  78 static struct class_device_attribute class_device_attrs[] = {
  79         __ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
  80 };
  81
  82 /**
  83  * drm_sysfs_device_add - adds a class device to sysfs for a character driver
  84  * @cs: pointer to the struct class that this device should be registered to.
  85  * @dev: the dev_t for the device to be added.
  86  * @device: a pointer to a struct device that is assiociated with this class device.
  87  * @fmt: string for the class device's name
  88  *
  89  * A struct class_device will be created in sysfs, registered to the specified
  90  * class.  A "dev" file will be created, showing the dev_t for the device.  The
  91  * pointer to the struct class_device will be returned from the call.  Any further
  92  * sysfs files that might be required can be created using this pointer.
  93  * Note: the struct class passed to this function must have previously been
  94  * created with a call to drm_sysfs_create().
  95  */
  96 struct class_device *drm_sysfs_device_add(struct class *cs, drm_head_t *head)
  97 {
  98         struct class_device *class_dev;
  99         int i;
 100
 101         class_dev = class_device_create(cs, NULL,
 102                                         MKDEV(DRM_MAJOR, head->minor),
 103                                         &(head->dev->pdev)->dev,
 104                                         "card%d", head->minor);
 105         if (!class_dev)
 106                 return NULL;
 107
 108         class_set_devdata(class_dev, head);
 109
 110         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
 111                 class_device_create_file(class_dev, &class_device_attrs[i]);
 112         return class_dev;
 113 }
 114
 115 /**
 116  * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
 117  * @dev: the dev_t of the device that was previously registered.
 118  *
 119  * This call unregisters and cleans up a class device that was created with a
 120  * call to drm_sysfs_device_add()
 121  */
 122 void drm_sysfs_device_remove(struct class_device *class_dev)
 123 {
 124         int i;
 125
 126         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
 127                 class_device_remove_file(class_dev, &class_device_attrs[i]);
 128         class_device_unregister(class_dev);
 129 }