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/config.h>
  16 #include <linux/device.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19
  20 #include "drm_core.h"
  21 #include "drmP.h"
  22
  23 /* Display the version of drm_core. This doesn't work right in current design */
  24 static ssize_t version_show(struct class *dev, char *buf)
  25 {
  26         return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
  27                        CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
  28 }
  29
  30 static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
  31
  32 /**
  33  * drm_sysfs_create - create a struct drm_sysfs_class structure
  34  * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
  35  * @name: pointer to a string for the name of this class.
  36  *
  37  * This is used to create a struct drm_sysfs_class pointer that can then be used
  38  * in calls to drm_sysfs_device_add().
  39  *
  40  * Note, the pointer created here is to be destroyed when finished by making a
  41  * call to drm_sysfs_destroy().
  42  */
  43 struct class *drm_sysfs_create(struct module *owner, char *name)
  44 {
  45         struct class *class;
  46
  47         class = class_create(owner, name);
  48         if (!class)
  49                 return class;
  50
  51         class_create_file(class, &class_attr_version);
  52         return class;
  53 }
  54
  55 /**
  56  * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
  57  * @cs: pointer to the struct drm_sysfs_class that is to be destroyed
  58  *
  59  * Note, the pointer to be destroyed must have been created with a call to
  60  * drm_sysfs_create().
  61  */
  62 void drm_sysfs_destroy(struct class *class)
  63 {
  64         if ((class == NULL) || (IS_ERR(class)))
  65                 return;
  66
  67         class_remove_file(class, &class_attr_version);
  68         class_destroy(class);
  69 }
  70
  71 static ssize_t show_dri(struct class_device *class_device, char *buf)
  72 {
  73         drm_device_t * dev = ((drm_head_t *)class_get_devdata(class_device))->dev;
  74         if (dev->driver->dri_library_name)
  75                 return dev->driver->dri_library_name(dev, buf);
  76         return snprintf(buf, PAGE_SIZE, "%s\n", dev->driver->pci_driver.name);
  77 }
  78
  79 static struct class_device_attribute class_device_attrs[] = {
  80         __ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
  81 };
  82
  83 /**
  84  * drm_sysfs_device_add - adds a class device to sysfs for a character driver
  85  * @cs: pointer to the struct class that this device should be registered to.
  86  * @dev: the dev_t for the device to be added.
  87  * @device: a pointer to a struct device that is assiociated with this class device.
  88  * @fmt: string for the class device's name
  89  *
  90  * A struct class_device will be created in sysfs, registered to the specified
  91  * class.  A "dev" file will be created, showing the dev_t for the device.  The
  92  * pointer to the struct class_device will be returned from the call.  Any further
  93  * sysfs files that might be required can be created using this pointer.
  94  * Note: the struct class passed to this function must have previously been
  95  * created with a call to drm_sysfs_create().
  96  */
  97 struct class_device *drm_sysfs_device_add(struct class *cs, drm_head_t *head)
  98 {
  99         struct class_device *class_dev;
 100         int i;
 101
 102         class_dev = class_device_create(cs, NULL,
 103                                         MKDEV(DRM_MAJOR, head->minor),
 104                                         &(head->dev->pdev)->dev,
 105                                         "card%d", head->minor);
 106         if (!class_dev)
 107                 return NULL;
 108
 109         class_set_devdata(class_dev, head);
 110
 111         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
 112                 class_device_create_file(class_dev, &class_device_attrs[i]);
 113         return class_dev;
 114 }
 115
 116 /**
 117  * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
 118  * @dev: the dev_t of the device that was previously registered.
 119  *
 120  * This call unregisters and cleans up a class device that was created with a
 121  * call to drm_sysfs_device_add()
 122  */
 123 void drm_sysfs_device_remove(struct class_device *class_dev)
 124 {
 125         int i;
 126
 127         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
 128                 class_device_remove_file(class_dev, &class_device_attrs[i]);
 129         class_device_unregister(class_dev);
 130 }