1 files changed, 208 insertions, 0 deletions
diff --git a/drivers/char/drm/drm_sysfs.c b/drivers/char/drm/drm_sysfs.c
new file mode 100644
index 000000000000..2fc10c4bbcdf
--- /dev/null
+++ b/drivers/char/drm/drm_sysfs.c
@@ -0,0 +1,208 @@
+/*
+ * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
+ *               extra sysfs attribute from DRM. Normal drm_sysfs_class
+ *               does not allow adding attributes.
+ *
+ * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
+ * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (c) 2003-2004 IBM Corp.
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/device.h>
+#include <linux/kdev_t.h>
+#include <linux/err.h>
+
+#include "drm_core.h"
+
+struct drm_sysfs_class {
+	struct class_device_attribute attr;
+	struct class class;
+};
+#define to_drm_sysfs_class(d) container_of(d, struct drm_sysfs_class, class)
+
+struct simple_dev {
+	struct list_head node;
+	dev_t dev;
+	struct class_device class_dev;
+};
+#define to_simple_dev(d) container_of(d, struct simple_dev, class_dev)
+
+static LIST_HEAD(simple_dev_list);
+static DEFINE_SPINLOCK(simple_dev_list_lock);
+
+static void release_simple_dev(struct class_device *class_dev)
+{
+	struct simple_dev *s_dev = to_simple_dev(class_dev);
+	kfree(s_dev);
+}
+
+static ssize_t show_dev(struct class_device *class_dev, char *buf)
+{
+	struct simple_dev *s_dev = to_simple_dev(class_dev);
+	return print_dev_t(buf, s_dev->dev);
+}
+
+static void drm_sysfs_class_release(struct class *class)
+{
+	struct drm_sysfs_class *cs = to_drm_sysfs_class(class);
+	kfree(cs);
+}
+
+/* Display the version of drm_core. This doesn't work right in current design */
+static ssize_t version_show(struct class *dev, char *buf)
+{
+	return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR,
+		       CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
+}
+
+static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
+
+/**
+ * drm_sysfs_create - create a struct drm_sysfs_class structure
+ * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
+ * @name: pointer to a string for the name of this class.
+ *
+ * This is used to create a struct drm_sysfs_class pointer that can then be used
+ * in calls to drm_sysfs_device_add().
+ *
+ * Note, the pointer created here is to be destroyed when finished by making a
+ * call to drm_sysfs_destroy().
+ */
+struct drm_sysfs_class *drm_sysfs_create(struct module *owner, char *name)
+{
+	struct drm_sysfs_class *cs;
+	int retval;
+
+	cs = kmalloc(sizeof(*cs), GFP_KERNEL);
+	if (!cs) {
+		retval = -ENOMEM;
+		goto error;
+	}
+	memset(cs, 0x00, sizeof(*cs));
+
+	cs->class.name = name;
+	cs->class.class_release = drm_sysfs_class_release;
+	cs->class.release = release_simple_dev;
+
+	cs->attr.attr.name = "dev";
+	cs->attr.attr.mode = S_IRUGO;
+	cs->attr.attr.owner = owner;
+	cs->attr.show = show_dev;
+	cs->attr.store = NULL;
+
+	retval = class_register(&cs->class);
+	if (retval)
+		goto error;
+	class_create_file(&cs->class, &class_attr_version);
+
+	return cs;
+
+      error:
+	kfree(cs);
+	return ERR_PTR(retval);
+}
+
+/**
+ * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
+ * @cs: pointer to the struct drm_sysfs_class that is to be destroyed
+ *
+ * Note, the pointer to be destroyed must have been created with a call to
+ * drm_sysfs_create().
+ */
+void drm_sysfs_destroy(struct drm_sysfs_class *cs)
+{
+	if ((cs == NULL) || (IS_ERR(cs)))
+		return;
+
+	class_unregister(&cs->class);
+}
+
+/**
+ * drm_sysfs_device_add - adds a class device to sysfs for a character driver
+ * @cs: pointer to the struct drm_sysfs_class that this device should be registered to.
+ * @dev: the dev_t for the device to be added.
+ * @device: a pointer to a struct device that is assiociated with this class device.
+ * @fmt: string for the class device's name
+ *
+ * A struct class_device will be created in sysfs, registered to the specified
+ * class.  A "dev" file will be created, showing the dev_t for the device.  The
+ * pointer to the struct class_device will be returned from the call.  Any further
+ * sysfs files that might be required can be created using this pointer.
+ * Note: the struct drm_sysfs_class passed to this function must have previously been
+ * created with a call to drm_sysfs_create().
+ */
+struct class_device *drm_sysfs_device_add(struct drm_sysfs_class *cs, dev_t dev,
+					  struct device *device,
+					  const char *fmt, ...)
+{
+	va_list args;
+	struct simple_dev *s_dev = NULL;
+	int retval;
+
+	if ((cs == NULL) || (IS_ERR(cs))) {
+		retval = -ENODEV;
+		goto error;
+	}
+
+	s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL);
+	if (!s_dev) {
+		retval = -ENOMEM;
+		goto error;
+	}
+	memset(s_dev, 0x00, sizeof(*s_dev));
+
+	s_dev->dev = dev;
+	s_dev->class_dev.dev = device;
+	s_dev->class_dev.class = &cs->class;
+
+	va_start(args, fmt);
+	vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args);
+	va_end(args);
+	retval = class_device_register(&s_dev->class_dev);
+	if (retval)
+		goto error;
+
+	class_device_create_file(&s_dev->class_dev, &cs->attr);
+
+	spin_lock(&simple_dev_list_lock);
+	list_add(&s_dev->node, &simple_dev_list);
+	spin_unlock(&simple_dev_list_lock);
+
+	return &s_dev->class_dev;
+
+      error:
+	kfree(s_dev);
+	return ERR_PTR(retval);
+}
+
+/**
+ * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
+ * @dev: the dev_t of the device that was previously registered.
+ *
+ * This call unregisters and cleans up a class device that was created with a
+ * call to drm_sysfs_device_add()
+ */
+void drm_sysfs_device_remove(dev_t dev)
+{
+	struct simple_dev *s_dev = NULL;
+	int found = 0;
+
+	spin_lock(&simple_dev_list_lock);
+	list_for_each_entry(s_dev, &simple_dev_list, node) {
+		if (s_dev->dev == dev) {
+			found = 1;
+			break;
+		}
+	}
+	if (found) {
+		list_del(&s_dev->node);
+		spin_unlock(&simple_dev_list_lock);
+		class_device_unregister(&s_dev->class_dev);
+	} else {
+		spin_unlock(&simple_dev_list_lock);
+	}
+}