File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/gpu/drm/drm_platform.c b/drivers/gpu/drm/drm_platform.c
new file mode 100644
index 0000000..644169e
--- /dev/null
+++ b/drivers/gpu/drm/drm_platform.c
@@ -0,0 +1,109 @@
+/*
+ * Derived from drm_pci.c
+ *
+ * Copyright 2003 José Fonseca.
+ * Copyright 2003 Leif Delgass.
+ * Copyright (c) 2009, Code Aurora Forum.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+ * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/export.h>
+#include <drm/drmP.h>
+
+/*
+ * Register.
+ *
+ * \param platdev - Platform device struture
+ * \return zero on success or a negative number on failure.
+ *
+ * Attempt to gets inter module "drm" information. If we are first
+ * then register the character device and inter module information.
+ * Try and register, if we fail to register, backout previous work.
+ */
+
+static int drm_get_platform_dev(struct platform_device *platdev,
+				struct drm_driver *driver)
+{
+	struct drm_device *dev;
+	int ret;
+
+	DRM_DEBUG("\n");
+
+	dev = drm_dev_alloc(driver, &platdev->dev);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->platformdev = platdev;
+
+	ret = drm_dev_register(dev, 0);
+	if (ret)
+		goto err_free;
+
+	DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
+		 driver->name, driver->major, driver->minor, driver->patchlevel,
+		 driver->date, dev->primary->index);
+
+	return 0;
+
+err_free:
+	drm_dev_unref(dev);
+	return ret;
+}
+
+int drm_platform_set_busid(struct drm_device *dev, struct drm_master *master)
+{
+	int id;
+
+	id = dev->platformdev->id;
+	if (id < 0)
+		id = 0;
+
+	master->unique = kasprintf(GFP_KERNEL, "platform:%s:%02d",
+						dev->platformdev->name, id);
+	if (!master->unique)
+		return -ENOMEM;
+
+	master->unique_len = strlen(master->unique);
+	return 0;
+}
+EXPORT_SYMBOL(drm_platform_set_busid);
+
+/**
+ * drm_platform_init - Register a platform device with the DRM subsystem
+ * @driver: DRM device driver
+ * @platform_device: platform device to register
+ *
+ * Registers the specified DRM device driver and platform device with the DRM
+ * subsystem, initializing a drm_device structure and calling the driver's
+ * .load() function.
+ *
+ * NOTE: This function is deprecated, please use drm_dev_alloc() and
+ * drm_dev_register() instead and remove your ->load() callback.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int drm_platform_init(struct drm_driver *driver, struct platform_device *platform_device)
+{
+	DRM_DEBUG("\n");
+
+	return drm_get_platform_dev(platform_device, driver);
+}
+EXPORT_SYMBOL(drm_platform_init);