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 #define to_drm_minor(d) container_of(d, struct drm_minor, kdev)
  23
  24 /**
  25  * drm_sysfs_suspend - DRM class suspend hook
  26  * @dev: Linux device to suspend
  27  * @state: power state to enter
  28  *
  29  * Just figures out what the actual struct drm_device associated with
  30  * @dev is and calls its suspend hook, if present.
  31  */
  32 static int drm_sysfs_suspend(struct device *dev, pm_message_t state)
  33 {
  34         struct drm_minor *drm_minor = to_drm_minor(dev);
  35         struct drm_device *drm_dev = drm_minor->dev;
  36
  37         if (drm_dev->driver->suspend)
  38                 return drm_dev->driver->suspend(drm_dev, state);
  39
  40         return 0;
  41 }
  42
  43 /**
  44  * drm_sysfs_resume - DRM class resume hook
  45  * @dev: Linux device to resume
  46  *
  47  * Just figures out what the actual struct drm_device associated with
  48  * @dev is and calls its resume hook, if present.
  49  */
  50 static int drm_sysfs_resume(struct device *dev)
  51 {
  52         struct drm_minor *drm_minor = to_drm_minor(dev);
  53         struct drm_device *drm_dev = drm_minor->dev;
  54
  55         if (drm_dev->driver->resume)
  56                 return drm_dev->driver->resume(drm_dev);
  57
  58         return 0;
  59 }
  60
  61 /* Display the version of drm_core. This doesn't work right in current design */
  62 static ssize_t version_show(struct class *dev, char *buf)
  63 {
  64         return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
  65                        CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
  66 }
  67
  68 static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
  69
  70 /**
  71  * drm_sysfs_create - create a struct drm_sysfs_class structure
  72  * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
  73  * @name: pointer to a string for the name of this class.
  74  *
  75  * This is used to create DRM class pointer that can then be used
  76  * in calls to drm_sysfs_device_add().
  77  *
  78  * Note, the pointer created here is to be destroyed when finished by making a
  79  * call to drm_sysfs_destroy().
  80  */
  81 struct class *drm_sysfs_create(struct module *owner, char *name)
  82 {
  83         struct class *class;
  84         int err;
  85
  86         class = class_create(owner, name);
  87         if (IS_ERR(class)) {
  88                 err = PTR_ERR(class);
  89                 goto err_out;
  90         }
  91
  92         class->suspend = drm_sysfs_suspend;
  93         class->resume = drm_sysfs_resume;
  94
  95         err = class_create_file(class, &class_attr_version);
  96         if (err)
  97                 goto err_out_class;
  98
  99         return class;
 100
 101 err_out_class:
 102         class_destroy(class);
 103 err_out:
 104         return ERR_PTR(err);
 105 }
 106
 107 /**
 108  * drm_sysfs_destroy - destroys DRM class
 109  *
 110  * Destroy the DRM device class.
 111  */
 112 void drm_sysfs_destroy(void)
 113 {
 114         if ((drm_class == NULL) || (IS_ERR(drm_class)))
 115                 return;
 116         class_remove_file(drm_class, &class_attr_version);
 117         class_destroy(drm_class);
 118 }
 119
 120 static ssize_t show_dri(struct device *device, struct device_attribute *attr,
 121                         char *buf)
 122 {
 123         struct drm_minor *drm_minor = to_drm_minor(device);
 124         struct drm_device *drm_dev = drm_minor->dev;
 125         if (drm_dev->driver->dri_library_name)
 126                 return drm_dev->driver->dri_library_name(drm_dev, buf);
 127         return snprintf(buf, PAGE_SIZE, "%s\n", drm_dev->driver->pci_driver.name);
 128 }
 129
 130 static struct device_attribute device_attrs[] = {
 131         __ATTR(dri_library_name, S_IRUGO, show_dri, NULL),
 132 };
 133
 134 /**
 135  * drm_sysfs_device_release - do nothing
 136  * @dev: Linux device
 137  *
 138  * Normally, this would free the DRM device associated with @dev, along
 139  * with cleaning up any other stuff.  But we do that in the DRM core, so
 140  * this function can just return and hope that the core does its job.
 141  */
 142 static void drm_sysfs_device_release(struct device *dev)
 143 {
 144         return;
 145 }
 146
 147 /**
 148  * drm_sysfs_device_add - adds a class device to sysfs for a character driver
 149  * @dev: DRM device to be added
 150  * @head: DRM head in question
 151  *
 152  * Add a DRM device to the DRM's device model class.  We use @dev's PCI device
 153  * as the parent for the Linux device, and make sure it has a file containing
 154  * the driver we're using (for userspace compatibility).
 155  */
 156 int drm_sysfs_device_add(struct drm_minor *minor)
 157 {
 158         int err;
 159         int i, j;
 160         char *minor_str;
 161
 162         minor->kdev.parent = &minor->dev->pdev->dev;
 163         minor->kdev.class = drm_class;
 164         minor->kdev.release = drm_sysfs_device_release;
 165         minor->kdev.devt = minor->device;
 166         minor_str = "card%d";
 167
 168         snprintf(minor->kdev.bus_id, BUS_ID_SIZE, minor_str, minor->index);
 169
 170         err = device_register(&minor->kdev);
 171         if (err) {
 172                 DRM_ERROR("device add failed: %d\n", err);
 173                 goto err_out;
 174         }
 175
 176         for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
 177                 err = device_create_file(&minor->kdev, &device_attrs[i]);
 178                 if (err)
 179                         goto err_out_files;
 180         }
 181
 182         return 0;
 183
 184 err_out_files:
 185         if (i > 0)
 186                 for (j = 0; j < i; j++)
 187                         device_remove_file(&minor->kdev, &device_attrs[i]);
 188         device_unregister(&minor->kdev);
 189 err_out:
 190
 191         return err;
 192 }
 193
 194 /**
 195  * drm_sysfs_device_remove - remove DRM device
 196  * @dev: DRM device to remove
 197  *
 198  * This call unregisters and cleans up a class device that was created with a
 199  * call to drm_sysfs_device_add()
 200  */
 201 void drm_sysfs_device_remove(struct drm_minor *minor)
 202 {
 203         int i;
 204
 205         for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
 206                 device_remove_file(&minor->kdev, &device_attrs[i]);
 207         device_unregister(&minor->kdev);
 208 }