drivers/gpu/drm/drm_platform.c

   1 /*
   2  * Derived from drm_pci.c
   3  *
   4  * Copyright 2003 José Fonseca.
   5  * Copyright 2003 Leif Delgass.
   6  * Copyright (c) 2009, Code Aurora Forum.
   7  * All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the next
  17  * paragraph) shall be included in all copies or substantial portions of the
  18  * Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  23  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  24  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  25  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  */
  27
  28 #include <linux/export.h>
  29 #include <drm/drmP.h>
  30
  31 /*
  32  * Register.
  33  *
  34  * \param platdev - Platform device struture
  35  * \return zero on success or a negative number on failure.
  36  *
  37  * Attempt to gets inter module "drm" information. If we are first
  38  * then register the character device and inter module information.
  39  * Try and register, if we fail to register, backout previous work.
  40  */
  41
  42 static int drm_get_platform_dev(struct platform_device *platdev,
  43                                 struct drm_driver *driver)
  44 {
  45         struct drm_device *dev;
  46         int ret;
  47
  48         DRM_DEBUG("\n");
  49
  50         dev = drm_dev_alloc(driver, &platdev->dev);
  51         if (!dev)
  52                 return -ENOMEM;
  53
  54         dev->platformdev = platdev;
  55
  56         ret = drm_dev_register(dev, 0);
  57         if (ret)
  58                 goto err_free;
  59
  60         DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
  61                  driver->name, driver->major, driver->minor, driver->patchlevel,
  62                  driver->date, dev->primary->index);
  63
  64         return 0;
  65
  66 err_free:
  67         drm_dev_unref(dev);
  68         return ret;
  69 }
  70
  71 static int drm_platform_set_busid(struct drm_device *dev, struct drm_master *master)
  72 {
  73         int len, ret, id;
  74
  75         master->unique_len = 13 + strlen(dev->platformdev->name);
  76         master->unique_size = master->unique_len;
  77         master->unique = kmalloc(master->unique_len + 1, GFP_KERNEL);
  78
  79         if (master->unique == NULL)
  80                 return -ENOMEM;
  81
  82         id = dev->platformdev->id;
  83
  84         /* if only a single instance of the platform device, id will be
  85          * set to -1.. use 0 instead to avoid a funny looking bus-id:
  86          */
  87         if (id == -1)
  88                 id = 0;
  89
  90         len = snprintf(master->unique, master->unique_len,
  91                         "platform:%s:%02d", dev->platformdev->name, id);
  92
  93         if (len > master->unique_len) {
  94                 DRM_ERROR("Unique buffer overflowed\n");
  95                 ret = -EINVAL;
  96                 goto err;
  97         }
  98
  99         return 0;
 100 err:
 101         return ret;
 102 }
 103
 104 static struct drm_bus drm_platform_bus = {
 105         .set_busid = drm_platform_set_busid,
 106 };
 107
 108 /**
 109  * drm_platform_init - Register a platform device with the DRM subsystem
 110  * @driver: DRM device driver
 111  * @platform_device: platform device to register
 112  *
 113  * Registers the specified DRM device driver and platform device with the DRM
 114  * subsystem, initializing a drm_device structure and calling the driver's
 115  * .load() function.
 116  *
 117  * Return: 0 on success or a negative error code on failure.
 118  */
 119 int drm_platform_init(struct drm_driver *driver, struct platform_device *platform_device)
 120 {
 121         DRM_DEBUG("\n");
 122
 123         driver->bus = &drm_platform_bus;
 124         return drm_get_platform_dev(platform_device, driver);
 125 }
 126 EXPORT_SYMBOL(drm_platform_init);