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         int err;
  46
  47         class = class_create(owner, name);
  48         if (IS_ERR(class)) {
  49                 err = PTR_ERR(class);
  50                 goto err_out;
  51         }
  52
  53         err = class_create_file(class, &class_attr_version);
  54         if (err)
  55                 goto err_out_class;
  56
  57         return class;
  58
  59 err_out_class:
  60         class_destroy(class);
  61 err_out:
  62         return ERR_PTR(err);
  63 }
  64
  65 /**
  66  * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
  67  * @cs: pointer to the struct drm_sysfs_class that is to be destroyed
  68  *
  69  * Note, the pointer to be destroyed must have been created with a call to
  70  * drm_sysfs_create().
  71  */
  72 void drm_sysfs_destroy(struct class *class)
  73 {
  74         if ((class == NULL) || (IS_ERR(class)))
  75                 return;
  76
  77         class_remove_file(class, &class_attr_version);
  78         class_destroy(class);
  79 }
  80
  81 static ssize_t show_dri(struct class_device *class_device, char *buf)
  82 {
  83         drm_device_t * dev = ((drm_head_t *)class_get_devdata(class_device))->dev;
  84         if (dev->driver->dri_library_name)
  85                 return dev->driver->dri_library_name(dev, buf);
  86         return snprintf(buf, PAGE_SIZE, "%s\n", dev->driver->pci_driver.name);
  87 }
  88
  89 static struct class_device_attribute class_device_attrs[] = {
  90         __ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
  91 };
  92
  93 /**
  94  * drm_sysfs_device_add - adds a class device to sysfs for a character driver
  95  * @cs: pointer to the struct class that this device should be registered to.
  96  * @dev: the dev_t for the device to be added.
  97  * @device: a pointer to a struct device that is assiociated with this class device.
  98  * @fmt: string for the class device's name
  99  *
 100  * A struct class_device will be created in sysfs, registered to the specified
 101  * class.  A "dev" file will be created, showing the dev_t for the device.  The
 102  * pointer to the struct class_device will be returned from the call.  Any further
 103  * sysfs files that might be required can be created using this pointer.
 104  * Note: the struct class passed to this function must have previously been
 105  * created with a call to drm_sysfs_create().
 106  */
 107 struct class_device *drm_sysfs_device_add(struct class *cs, drm_head_t *head)
 108 {
 109         struct class_device *class_dev;
 110         int i, j, err;
 111
 112         class_dev = class_device_create(cs, NULL,
 113                                         MKDEV(DRM_MAJOR, head->minor),
 114                                         &(head->dev->pdev)->dev,
 115                                         "card%d", head->minor);
 116         if (IS_ERR(class_dev)) {
 117                 err = PTR_ERR(class_dev);
 118                 goto err_out;
 119         }
 120
 121         class_set_devdata(class_dev, head);
 122
 123         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++) {
 124                 err = class_device_create_file(class_dev,
 125                                                &class_device_attrs[i]);
 126                 if (err)
 127                         goto err_out_files;
 128         }
 129
 130         return class_dev;
 131
 132 err_out_files:
 133         if (i > 0)
 134                 for (j = 0; j < i; j++)
 135                         class_device_remove_file(class_dev,
 136                                                  &class_device_attrs[i]);
 137         class_device_unregister(class_dev);
 138 err_out:
 139         return ERR_PTR(err);
 140 }
 141
 142 /**
 143  * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
 144  * @dev: the dev_t of the device that was previously registered.
 145  *
 146  * This call unregisters and cleans up a class device that was created with a
 147  * call to drm_sysfs_device_add()
 148  */
 149 void drm_sysfs_device_remove(struct class_device *class_dev)
 150 {
 151         int i;
 152
 153         for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
 154                 class_device_remove_file(class_dev, &class_device_attrs[i]);
 155         class_device_unregister(class_dev);
 156 }