Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / gpu / drm / drm_fb_helper.c
diff --git a/kernel/drivers/gpu/drm/drm_fb_helper.c b/kernel/drivers/gpu/drm/drm_fb_helper.c
new file mode 100644 (file)
index 0000000..cac4229
--- /dev/null
@@ -0,0 +1,1838 @@
+/*
+ * Copyright (c) 2006-2009 Red Hat Inc.
+ * Copyright (c) 2006-2008 Intel Corporation
+ * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
+ *
+ * DRM framebuffer helper functions
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ *
+ * Authors:
+ *      Dave Airlie <airlied@linux.ie>
+ *      Jesse Barnes <jesse.barnes@intel.com>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/sysrq.h>
+#include <linux/slab.h>
+#include <linux/fb.h>
+#include <linux/module.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+
+static LIST_HEAD(kernel_fb_helper_list);
+
+/**
+ * DOC: fbdev helpers
+ *
+ * The fb helper functions are useful to provide an fbdev on top of a drm kernel
+ * mode setting driver. They can be used mostly independently from the crtc
+ * helper functions used by many drivers to implement the kernel mode setting
+ * interfaces.
+ *
+ * Initialization is done as a four-step process with drm_fb_helper_prepare(),
+ * drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and
+ * drm_fb_helper_initial_config(). Drivers with fancier requirements than the
+ * default behaviour can override the third step with their own code.
+ * Teardown is done with drm_fb_helper_fini().
+ *
+ * At runtime drivers should restore the fbdev console by calling
+ * drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
+ * should also notify the fb helper code from updates to the output
+ * configuration by calling drm_fb_helper_hotplug_event(). For easier
+ * integration with the output polling code in drm_crtc_helper.c the modeset
+ * code provides a ->output_poll_changed callback.
+ *
+ * All other functions exported by the fb helper library can be used to
+ * implement the fbdev driver interface by the driver.
+ *
+ * It is possible, though perhaps somewhat tricky, to implement race-free
+ * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
+ * helper must be called first to initialize the minimum required to make
+ * hotplug detection work. Drivers also need to make sure to properly set up
+ * the dev->mode_config.funcs member. After calling drm_kms_helper_poll_init()
+ * it is safe to enable interrupts and start processing hotplug events. At the
+ * same time, drivers should initialize all modeset objects such as CRTCs,
+ * encoders and connectors. To finish up the fbdev helper initialization, the
+ * drm_fb_helper_init() function is called. To probe for all attached displays
+ * and set up an initial configuration using the detected hardware, drivers
+ * should call drm_fb_helper_single_add_all_connectors() followed by
+ * drm_fb_helper_initial_config().
+ */
+
+/**
+ * drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev
+ *                                            emulation helper
+ * @fb_helper: fbdev initialized with drm_fb_helper_init
+ *
+ * This functions adds all the available connectors for use with the given
+ * fb_helper. This is a separate step to allow drivers to freely assign
+ * connectors to the fbdev, e.g. if some are reserved for special purposes or
+ * not adequate to be used for the fbcon.
+ *
+ * Since this is part of the initial setup before the fbdev is published, no
+ * locking is required.
+ */
+int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_connector *connector;
+       int i;
+
+       list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+               struct drm_fb_helper_connector *fb_helper_connector;
+
+               fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
+               if (!fb_helper_connector)
+                       goto fail;
+
+               fb_helper_connector->connector = connector;
+               fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
+       }
+       return 0;
+fail:
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               kfree(fb_helper->connector_info[i]);
+               fb_helper->connector_info[i] = NULL;
+       }
+       fb_helper->connector_count = 0;
+       return -ENOMEM;
+}
+EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
+
+int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector)
+{
+       struct drm_fb_helper_connector **temp;
+       struct drm_fb_helper_connector *fb_helper_connector;
+
+       WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+       if (fb_helper->connector_count + 1 > fb_helper->connector_info_alloc_count) {
+               temp = krealloc(fb_helper->connector_info, sizeof(struct drm_fb_helper_connector *) * (fb_helper->connector_count + 1), GFP_KERNEL);
+               if (!temp)
+                       return -ENOMEM;
+
+               fb_helper->connector_info_alloc_count = fb_helper->connector_count + 1;
+               fb_helper->connector_info = temp;
+       }
+
+
+       fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
+       if (!fb_helper_connector)
+               return -ENOMEM;
+
+       fb_helper_connector->connector = connector;
+       fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
+
+static void remove_from_modeset(struct drm_mode_set *set,
+               struct drm_connector *connector)
+{
+       int i, j;
+
+       for (i = 0; i < set->num_connectors; i++) {
+               if (set->connectors[i] == connector)
+                       break;
+       }
+
+       if (i == set->num_connectors)
+               return;
+
+       for (j = i + 1; j < set->num_connectors; j++) {
+               set->connectors[j - 1] = set->connectors[j];
+       }
+       set->num_connectors--;
+
+       /* because i915 is pissy about this..
+        * TODO maybe need to makes sure we set it back to !=NULL somewhere?
+        */
+       if (set->num_connectors == 0)
+               set->fb = NULL;
+}
+
+int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
+                                      struct drm_connector *connector)
+{
+       struct drm_fb_helper_connector *fb_helper_connector;
+       int i, j;
+
+       WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               if (fb_helper->connector_info[i]->connector == connector)
+                       break;
+       }
+
+       if (i == fb_helper->connector_count)
+               return -EINVAL;
+       fb_helper_connector = fb_helper->connector_info[i];
+
+       for (j = i + 1; j < fb_helper->connector_count; j++) {
+               fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
+       }
+       fb_helper->connector_count--;
+       kfree(fb_helper_connector);
+
+       /* also cleanup dangling references to the connector: */
+       for (i = 0; i < fb_helper->crtc_count; i++)
+               remove_from_modeset(&fb_helper->crtc_info[i].mode_set, connector);
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
+
+static void drm_fb_helper_save_lut_atomic(struct drm_crtc *crtc, struct drm_fb_helper *helper)
+{
+       uint16_t *r_base, *g_base, *b_base;
+       int i;
+
+       if (helper->funcs->gamma_get == NULL)
+               return;
+
+       r_base = crtc->gamma_store;
+       g_base = r_base + crtc->gamma_size;
+       b_base = g_base + crtc->gamma_size;
+
+       for (i = 0; i < crtc->gamma_size; i++)
+               helper->funcs->gamma_get(crtc, &r_base[i], &g_base[i], &b_base[i], i);
+}
+
+static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
+{
+       uint16_t *r_base, *g_base, *b_base;
+
+       if (crtc->funcs->gamma_set == NULL)
+               return;
+
+       r_base = crtc->gamma_store;
+       g_base = r_base + crtc->gamma_size;
+       b_base = g_base + crtc->gamma_size;
+
+       crtc->funcs->gamma_set(crtc, r_base, g_base, b_base, 0, crtc->gamma_size);
+}
+
+/**
+ * drm_fb_helper_debug_enter - implementation for ->fb_debug_enter
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_debug_enter(struct fb_info *info)
+{
+       struct drm_fb_helper *helper = info->par;
+       const struct drm_crtc_helper_funcs *funcs;
+       int i;
+
+       list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
+               for (i = 0; i < helper->crtc_count; i++) {
+                       struct drm_mode_set *mode_set =
+                               &helper->crtc_info[i].mode_set;
+
+                       if (!mode_set->crtc->enabled)
+                               continue;
+
+                       funcs = mode_set->crtc->helper_private;
+                       drm_fb_helper_save_lut_atomic(mode_set->crtc, helper);
+                       funcs->mode_set_base_atomic(mode_set->crtc,
+                                                   mode_set->fb,
+                                                   mode_set->x,
+                                                   mode_set->y,
+                                                   ENTER_ATOMIC_MODE_SET);
+               }
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_debug_enter);
+
+/* Find the real fb for a given fb helper CRTC */
+static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc)
+{
+       struct drm_device *dev = crtc->dev;
+       struct drm_crtc *c;
+
+       list_for_each_entry(c, &dev->mode_config.crtc_list, head) {
+               if (crtc->base.id == c->base.id)
+                       return c->primary->fb;
+       }
+
+       return NULL;
+}
+
+/**
+ * drm_fb_helper_debug_leave - implementation for ->fb_debug_leave
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_debug_leave(struct fb_info *info)
+{
+       struct drm_fb_helper *helper = info->par;
+       struct drm_crtc *crtc;
+       const struct drm_crtc_helper_funcs *funcs;
+       struct drm_framebuffer *fb;
+       int i;
+
+       for (i = 0; i < helper->crtc_count; i++) {
+               struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set;
+               crtc = mode_set->crtc;
+               funcs = crtc->helper_private;
+               fb = drm_mode_config_fb(crtc);
+
+               if (!crtc->enabled)
+                       continue;
+
+               if (!fb) {
+                       DRM_ERROR("no fb to restore??\n");
+                       continue;
+               }
+
+               drm_fb_helper_restore_lut_atomic(mode_set->crtc);
+               funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
+                                           crtc->y, LEAVE_ATOMIC_MODE_SET);
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_debug_leave);
+
+static bool restore_fbdev_mode(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_plane *plane;
+       bool error = false;
+       int i;
+
+       drm_warn_on_modeset_not_all_locked(dev);
+
+       list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
+               if (plane->type != DRM_PLANE_TYPE_PRIMARY)
+                       drm_plane_force_disable(plane);
+
+               if (dev->mode_config.rotation_property) {
+                       drm_mode_plane_set_obj_prop(plane,
+                                                   dev->mode_config.rotation_property,
+                                                   BIT(DRM_ROTATE_0));
+               }
+       }
+
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
+               struct drm_crtc *crtc = mode_set->crtc;
+               int ret;
+
+               if (crtc->funcs->cursor_set) {
+                       ret = crtc->funcs->cursor_set(crtc, NULL, 0, 0, 0);
+                       if (ret)
+                               error = true;
+               }
+
+               ret = drm_mode_set_config_internal(mode_set);
+               if (ret)
+                       error = true;
+       }
+       return error;
+}
+/**
+ * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
+ * @fb_helper: fbcon to restore
+ *
+ * This should be called from driver's drm ->lastclose callback
+ * when implementing an fbcon on top of kms using this helper. This ensures that
+ * the user isn't greeted with a black screen when e.g. X dies.
+ *
+ * Use this variant if you need to bypass locking (panic), or already
+ * hold all modeset locks.  Otherwise use drm_fb_helper_restore_fbdev_mode_unlocked()
+ */
+static bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
+{
+       return restore_fbdev_mode(fb_helper);
+}
+
+/**
+ * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
+ * @fb_helper: fbcon to restore
+ *
+ * This should be called from driver's drm ->lastclose callback
+ * when implementing an fbcon on top of kms using this helper. This ensures that
+ * the user isn't greeted with a black screen when e.g. X dies.
+ */
+bool drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       bool ret;
+       bool do_delayed = false;
+
+       drm_modeset_lock_all(dev);
+       ret = restore_fbdev_mode(fb_helper);
+
+       do_delayed = fb_helper->delayed_hotplug;
+       if (do_delayed)
+               fb_helper->delayed_hotplug = false;
+       drm_modeset_unlock_all(dev);
+
+       if (do_delayed)
+               drm_fb_helper_hotplug_event(fb_helper);
+       return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
+
+/*
+ * restore fbcon display for all kms driver's using this helper, used for sysrq
+ * and panic handling.
+ */
+static bool drm_fb_helper_force_kernel_mode(void)
+{
+       bool ret, error = false;
+       struct drm_fb_helper *helper;
+
+       if (list_empty(&kernel_fb_helper_list))
+               return false;
+
+       list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
+               struct drm_device *dev = helper->dev;
+
+               if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
+                       continue;
+
+               /*
+                * NOTE: Use trylock mode to avoid deadlocks and sleeping in
+                * panic context.
+                */
+               if (__drm_modeset_lock_all(dev, true) != 0) {
+                       error = true;
+                       continue;
+               }
+
+               ret = drm_fb_helper_restore_fbdev_mode(helper);
+               if (ret)
+                       error = true;
+
+               drm_modeset_unlock_all(dev);
+       }
+       return error;
+}
+
+static int drm_fb_helper_panic(struct notifier_block *n, unsigned long ununsed,
+                       void *panic_str)
+{
+       /*
+        * It's a waste of time and effort to switch back to text console
+        * if the kernel should reboot before panic messages can be seen.
+        */
+       if (panic_timeout < 0)
+               return 0;
+
+       pr_err("panic occurred, switching back to text console\n");
+       return drm_fb_helper_force_kernel_mode();
+}
+
+static struct notifier_block paniced = {
+       .notifier_call = drm_fb_helper_panic,
+};
+
+static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_crtc *crtc;
+       int bound = 0, crtcs_bound = 0;
+
+       /* Sometimes user space wants everything disabled, so don't steal the
+        * display if there's a master. */
+       if (dev->primary->master)
+               return false;
+
+       list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+               if (crtc->primary->fb)
+                       crtcs_bound++;
+               if (crtc->primary->fb == fb_helper->fb)
+                       bound++;
+       }
+
+       if (bound < crtcs_bound)
+               return false;
+
+       return true;
+}
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
+{
+       bool ret;
+       ret = drm_fb_helper_force_kernel_mode();
+       if (ret == true)
+               DRM_ERROR("Failed to restore crtc configuration\n");
+}
+static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
+
+static void drm_fb_helper_sysrq(int dummy1)
+{
+       schedule_work(&drm_fb_helper_restore_work);
+}
+
+static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
+       .handler = drm_fb_helper_sysrq,
+       .help_msg = "force-fb(V)",
+       .action_msg = "Restore framebuffer console",
+};
+#else
+static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
+#endif
+
+static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_crtc *crtc;
+       struct drm_connector *connector;
+       int i, j;
+
+       /*
+        * fbdev->blank can be called from irq context in case of a panic.
+        * Since we already have our own special panic handler which will
+        * restore the fbdev console mode completely, just bail out early.
+        */
+       if (oops_in_progress)
+               return;
+
+       /*
+        * For each CRTC in this fb, turn the connectors on/off.
+        */
+       drm_modeset_lock_all(dev);
+       if (!drm_fb_helper_is_bound(fb_helper)) {
+               drm_modeset_unlock_all(dev);
+               return;
+       }
+
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               crtc = fb_helper->crtc_info[i].mode_set.crtc;
+
+               if (!crtc->enabled)
+                       continue;
+
+               /* Walk the connectors & encoders on this fb turning them on/off */
+               for (j = 0; j < fb_helper->connector_count; j++) {
+                       connector = fb_helper->connector_info[j]->connector;
+                       connector->funcs->dpms(connector, dpms_mode);
+                       drm_object_property_set_value(&connector->base,
+                               dev->mode_config.dpms_property, dpms_mode);
+               }
+       }
+       drm_modeset_unlock_all(dev);
+}
+
+/**
+ * drm_fb_helper_blank - implementation for ->fb_blank
+ * @blank: desired blanking state
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_blank(int blank, struct fb_info *info)
+{
+       switch (blank) {
+       /* Display: On; HSync: On, VSync: On */
+       case FB_BLANK_UNBLANK:
+               drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
+               break;
+       /* Display: Off; HSync: On, VSync: On */
+       case FB_BLANK_NORMAL:
+               drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
+               break;
+       /* Display: Off; HSync: Off, VSync: On */
+       case FB_BLANK_HSYNC_SUSPEND:
+               drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
+               break;
+       /* Display: Off; HSync: On, VSync: Off */
+       case FB_BLANK_VSYNC_SUSPEND:
+               drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
+               break;
+       /* Display: Off; HSync: Off, VSync: Off */
+       case FB_BLANK_POWERDOWN:
+               drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
+               break;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_blank);
+
+static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
+{
+       int i;
+
+       for (i = 0; i < helper->connector_count; i++)
+               kfree(helper->connector_info[i]);
+       kfree(helper->connector_info);
+       for (i = 0; i < helper->crtc_count; i++) {
+               kfree(helper->crtc_info[i].mode_set.connectors);
+               if (helper->crtc_info[i].mode_set.mode)
+                       drm_mode_destroy(helper->dev, helper->crtc_info[i].mode_set.mode);
+       }
+       kfree(helper->crtc_info);
+}
+
+/**
+ * drm_fb_helper_prepare - setup a drm_fb_helper structure
+ * @dev: DRM device
+ * @helper: driver-allocated fbdev helper structure to set up
+ * @funcs: pointer to structure of functions associate with this helper
+ *
+ * Sets up the bare minimum to make the framebuffer helper usable. This is
+ * useful to implement race-free initialization of the polling helpers.
+ */
+void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
+                          const struct drm_fb_helper_funcs *funcs)
+{
+       INIT_LIST_HEAD(&helper->kernel_fb_list);
+       helper->funcs = funcs;
+       helper->dev = dev;
+}
+EXPORT_SYMBOL(drm_fb_helper_prepare);
+
+/**
+ * drm_fb_helper_init - initialize a drm_fb_helper structure
+ * @dev: drm device
+ * @fb_helper: driver-allocated fbdev helper structure to initialize
+ * @crtc_count: maximum number of crtcs to support in this fbdev emulation
+ * @max_conn_count: max connector count
+ *
+ * This allocates the structures for the fbdev helper with the given limits.
+ * Note that this won't yet touch the hardware (through the driver interfaces)
+ * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
+ * to allow driver writes more control over the exact init sequence.
+ *
+ * Drivers must call drm_fb_helper_prepare() before calling this function.
+ *
+ * RETURNS:
+ * Zero if everything went ok, nonzero otherwise.
+ */
+int drm_fb_helper_init(struct drm_device *dev,
+                      struct drm_fb_helper *fb_helper,
+                      int crtc_count, int max_conn_count)
+{
+       struct drm_crtc *crtc;
+       int i;
+
+       if (!max_conn_count)
+               return -EINVAL;
+
+       fb_helper->crtc_info = kcalloc(crtc_count, sizeof(struct drm_fb_helper_crtc), GFP_KERNEL);
+       if (!fb_helper->crtc_info)
+               return -ENOMEM;
+
+       fb_helper->crtc_count = crtc_count;
+       fb_helper->connector_info = kcalloc(dev->mode_config.num_connector, sizeof(struct drm_fb_helper_connector *), GFP_KERNEL);
+       if (!fb_helper->connector_info) {
+               kfree(fb_helper->crtc_info);
+               return -ENOMEM;
+       }
+       fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
+       fb_helper->connector_count = 0;
+
+       for (i = 0; i < crtc_count; i++) {
+               fb_helper->crtc_info[i].mode_set.connectors =
+                       kcalloc(max_conn_count,
+                               sizeof(struct drm_connector *),
+                               GFP_KERNEL);
+
+               if (!fb_helper->crtc_info[i].mode_set.connectors)
+                       goto out_free;
+               fb_helper->crtc_info[i].mode_set.num_connectors = 0;
+       }
+
+       i = 0;
+       list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+               fb_helper->crtc_info[i].mode_set.crtc = crtc;
+               i++;
+       }
+
+       return 0;
+out_free:
+       drm_fb_helper_crtc_free(fb_helper);
+       return -ENOMEM;
+}
+EXPORT_SYMBOL(drm_fb_helper_init);
+
+void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
+{
+       if (!list_empty(&fb_helper->kernel_fb_list)) {
+               list_del(&fb_helper->kernel_fb_list);
+               if (list_empty(&kernel_fb_helper_list)) {
+                       pr_info("drm: unregistered panic notifier\n");
+                       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                                        &paniced);
+                       unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
+               }
+       }
+
+       drm_fb_helper_crtc_free(fb_helper);
+
+}
+EXPORT_SYMBOL(drm_fb_helper_fini);
+
+static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
+                    u16 blue, u16 regno, struct fb_info *info)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct drm_framebuffer *fb = fb_helper->fb;
+       int pindex;
+
+       if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
+               u32 *palette;
+               u32 value;
+               /* place color in psuedopalette */
+               if (regno > 16)
+                       return -EINVAL;
+               palette = (u32 *)info->pseudo_palette;
+               red >>= (16 - info->var.red.length);
+               green >>= (16 - info->var.green.length);
+               blue >>= (16 - info->var.blue.length);
+               value = (red << info->var.red.offset) |
+                       (green << info->var.green.offset) |
+                       (blue << info->var.blue.offset);
+               if (info->var.transp.length > 0) {
+                       u32 mask = (1 << info->var.transp.length) - 1;
+                       mask <<= info->var.transp.offset;
+                       value |= mask;
+               }
+               palette[regno] = value;
+               return 0;
+       }
+
+       /*
+        * The driver really shouldn't advertise pseudo/directcolor
+        * visuals if it can't deal with the palette.
+        */
+       if (WARN_ON(!fb_helper->funcs->gamma_set ||
+                   !fb_helper->funcs->gamma_get))
+               return -EINVAL;
+
+       pindex = regno;
+
+       if (fb->bits_per_pixel == 16) {
+               pindex = regno << 3;
+
+               if (fb->depth == 16 && regno > 63)
+                       return -EINVAL;
+               if (fb->depth == 15 && regno > 31)
+                       return -EINVAL;
+
+               if (fb->depth == 16) {
+                       u16 r, g, b;
+                       int i;
+                       if (regno < 32) {
+                               for (i = 0; i < 8; i++)
+                                       fb_helper->funcs->gamma_set(crtc, red,
+                                               green, blue, pindex + i);
+                       }
+
+                       fb_helper->funcs->gamma_get(crtc, &r,
+                                                   &g, &b,
+                                                   pindex >> 1);
+
+                       for (i = 0; i < 4; i++)
+                               fb_helper->funcs->gamma_set(crtc, r,
+                                                           green, b,
+                                                           (pindex >> 1) + i);
+               }
+       }
+
+       if (fb->depth != 16)
+               fb_helper->funcs->gamma_set(crtc, red, green, blue, pindex);
+       return 0;
+}
+
+/**
+ * drm_fb_helper_setcmap - implementation for ->fb_setcmap
+ * @cmap: cmap to set
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct drm_device *dev = fb_helper->dev;
+       const struct drm_crtc_helper_funcs *crtc_funcs;
+       u16 *red, *green, *blue, *transp;
+       struct drm_crtc *crtc;
+       int i, j, rc = 0;
+       int start;
+
+       if (__drm_modeset_lock_all(dev, !!oops_in_progress)) {
+               return -EBUSY;
+       }
+       if (!drm_fb_helper_is_bound(fb_helper)) {
+               drm_modeset_unlock_all(dev);
+               return -EBUSY;
+       }
+
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               crtc = fb_helper->crtc_info[i].mode_set.crtc;
+               crtc_funcs = crtc->helper_private;
+
+               red = cmap->red;
+               green = cmap->green;
+               blue = cmap->blue;
+               transp = cmap->transp;
+               start = cmap->start;
+
+               for (j = 0; j < cmap->len; j++) {
+                       u16 hred, hgreen, hblue, htransp = 0xffff;
+
+                       hred = *red++;
+                       hgreen = *green++;
+                       hblue = *blue++;
+
+                       if (transp)
+                               htransp = *transp++;
+
+                       rc = setcolreg(crtc, hred, hgreen, hblue, start++, info);
+                       if (rc)
+                               goto out;
+               }
+               if (crtc_funcs->load_lut)
+                       crtc_funcs->load_lut(crtc);
+       }
+ out:
+       drm_modeset_unlock_all(dev);
+       return rc;
+}
+EXPORT_SYMBOL(drm_fb_helper_setcmap);
+
+/**
+ * drm_fb_helper_check_var - implementation for ->fb_check_var
+ * @var: screeninfo to check
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
+                           struct fb_info *info)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct drm_framebuffer *fb = fb_helper->fb;
+       int depth;
+
+       if (var->pixclock != 0 || in_dbg_master())
+               return -EINVAL;
+
+       /* Need to resize the fb object !!! */
+       if (var->bits_per_pixel > fb->bits_per_pixel ||
+           var->xres > fb->width || var->yres > fb->height ||
+           var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
+               DRM_DEBUG("fb userspace requested width/height/bpp is greater than current fb "
+                         "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
+                         var->xres, var->yres, var->bits_per_pixel,
+                         var->xres_virtual, var->yres_virtual,
+                         fb->width, fb->height, fb->bits_per_pixel);
+               return -EINVAL;
+       }
+
+       switch (var->bits_per_pixel) {
+       case 16:
+               depth = (var->green.length == 6) ? 16 : 15;
+               break;
+       case 32:
+               depth = (var->transp.length > 0) ? 32 : 24;
+               break;
+       default:
+               depth = var->bits_per_pixel;
+               break;
+       }
+
+       switch (depth) {
+       case 8:
+               var->red.offset = 0;
+               var->green.offset = 0;
+               var->blue.offset = 0;
+               var->red.length = 8;
+               var->green.length = 8;
+               var->blue.length = 8;
+               var->transp.length = 0;
+               var->transp.offset = 0;
+               break;
+       case 15:
+               var->red.offset = 10;
+               var->green.offset = 5;
+               var->blue.offset = 0;
+               var->red.length = 5;
+               var->green.length = 5;
+               var->blue.length = 5;
+               var->transp.length = 1;
+               var->transp.offset = 15;
+               break;
+       case 16:
+               var->red.offset = 11;
+               var->green.offset = 5;
+               var->blue.offset = 0;
+               var->red.length = 5;
+               var->green.length = 6;
+               var->blue.length = 5;
+               var->transp.length = 0;
+               var->transp.offset = 0;
+               break;
+       case 24:
+               var->red.offset = 16;
+               var->green.offset = 8;
+               var->blue.offset = 0;
+               var->red.length = 8;
+               var->green.length = 8;
+               var->blue.length = 8;
+               var->transp.length = 0;
+               var->transp.offset = 0;
+               break;
+       case 32:
+               var->red.offset = 16;
+               var->green.offset = 8;
+               var->blue.offset = 0;
+               var->red.length = 8;
+               var->green.length = 8;
+               var->blue.length = 8;
+               var->transp.length = 8;
+               var->transp.offset = 24;
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_check_var);
+
+/**
+ * drm_fb_helper_set_par - implementation for ->fb_set_par
+ * @info: fbdev registered by the helper
+ *
+ * This will let fbcon do the mode init and is called at initialization time by
+ * the fbdev core when registering the driver, and later on through the hotplug
+ * callback.
+ */
+int drm_fb_helper_set_par(struct fb_info *info)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct fb_var_screeninfo *var = &info->var;
+
+       if (var->pixclock != 0) {
+               DRM_ERROR("PIXEL CLOCK SET\n");
+               return -EINVAL;
+       }
+
+       drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_set_par);
+
+/**
+ * drm_fb_helper_pan_display - implementation for ->fb_pan_display
+ * @var: updated screen information
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
+                             struct fb_info *info)
+{
+       struct drm_fb_helper *fb_helper = info->par;
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_mode_set *modeset;
+       int ret = 0;
+       int i;
+
+       if (__drm_modeset_lock_all(dev, !!oops_in_progress)) {
+               return -EBUSY;
+       }
+       if (!drm_fb_helper_is_bound(fb_helper)) {
+               drm_modeset_unlock_all(dev);
+               return -EBUSY;
+       }
+
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               modeset = &fb_helper->crtc_info[i].mode_set;
+
+               modeset->x = var->xoffset;
+               modeset->y = var->yoffset;
+
+               if (modeset->num_connectors) {
+                       ret = drm_mode_set_config_internal(modeset);
+                       if (!ret) {
+                               info->var.xoffset = var->xoffset;
+                               info->var.yoffset = var->yoffset;
+                       }
+               }
+       }
+       drm_modeset_unlock_all(dev);
+       return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_pan_display);
+
+/*
+ * Allocates the backing storage and sets up the fbdev info structure through
+ * the ->fb_probe callback and then registers the fbdev and sets up the panic
+ * notifier.
+ */
+static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
+                                        int preferred_bpp)
+{
+       int ret = 0;
+       int crtc_count = 0;
+       int i;
+       struct fb_info *info;
+       struct drm_fb_helper_surface_size sizes;
+       int gamma_size = 0;
+
+       memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
+       sizes.surface_depth = 24;
+       sizes.surface_bpp = 32;
+       sizes.fb_width = (unsigned)-1;
+       sizes.fb_height = (unsigned)-1;
+
+       /* if driver picks 8 or 16 by default use that
+          for both depth/bpp */
+       if (preferred_bpp != sizes.surface_bpp)
+               sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
+
+       /* first up get a count of crtcs now in use and new min/maxes width/heights */
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               struct drm_fb_helper_connector *fb_helper_conn = fb_helper->connector_info[i];
+               struct drm_cmdline_mode *cmdline_mode;
+
+               cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
+
+               if (cmdline_mode->bpp_specified) {
+                       switch (cmdline_mode->bpp) {
+                       case 8:
+                               sizes.surface_depth = sizes.surface_bpp = 8;
+                               break;
+                       case 15:
+                               sizes.surface_depth = 15;
+                               sizes.surface_bpp = 16;
+                               break;
+                       case 16:
+                               sizes.surface_depth = sizes.surface_bpp = 16;
+                               break;
+                       case 24:
+                               sizes.surface_depth = sizes.surface_bpp = 24;
+                               break;
+                       case 32:
+                               sizes.surface_depth = 24;
+                               sizes.surface_bpp = 32;
+                               break;
+                       }
+                       break;
+               }
+       }
+
+       crtc_count = 0;
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               struct drm_display_mode *desired_mode;
+               struct drm_mode_set *mode_set;
+               int x, y, j;
+               /* in case of tile group, are we the last tile vert or horiz?
+                * If no tile group you are always the last one both vertically
+                * and horizontally
+                */
+               bool lastv = true, lasth = true;
+
+               desired_mode = fb_helper->crtc_info[i].desired_mode;
+               mode_set = &fb_helper->crtc_info[i].mode_set;
+
+               if (!desired_mode)
+                       continue;
+
+               crtc_count++;
+
+               x = fb_helper->crtc_info[i].x;
+               y = fb_helper->crtc_info[i].y;
+
+               if (gamma_size == 0)
+                       gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size;
+
+               sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
+               sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
+
+               for (j = 0; j < mode_set->num_connectors; j++) {
+                       struct drm_connector *connector = mode_set->connectors[j];
+                       if (connector->has_tile) {
+                               lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
+                               lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
+                               /* cloning to multiple tiles is just crazy-talk, so: */
+                               break;
+                       }
+               }
+
+               if (lasth)
+                       sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
+               if (lastv)
+                       sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
+       }
+
+       if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
+               /* hmm everyone went away - assume VGA cable just fell out
+                  and will come back later. */
+               DRM_INFO("Cannot find any crtc or sizes - going 1024x768\n");
+               sizes.fb_width = sizes.surface_width = 1024;
+               sizes.fb_height = sizes.surface_height = 768;
+       }
+
+       /* push down into drivers */
+       ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
+       if (ret < 0)
+               return ret;
+
+       info = fb_helper->fbdev;
+
+       /*
+        * Set the fb pointer - usually drm_setup_crtcs does this for hotplug
+        * events, but at init time drm_setup_crtcs needs to be called before
+        * the fb is allocated (since we need to figure out the desired size of
+        * the fb before we can allocate it ...). Hence we need to fix things up
+        * here again.
+        */
+       for (i = 0; i < fb_helper->crtc_count; i++)
+               if (fb_helper->crtc_info[i].mode_set.num_connectors)
+                       fb_helper->crtc_info[i].mode_set.fb = fb_helper->fb;
+
+
+       info->var.pixclock = 0;
+       if (register_framebuffer(info) < 0)
+               return -EINVAL;
+
+       dev_info(fb_helper->dev->dev, "fb%d: %s frame buffer device\n",
+                       info->node, info->fix.id);
+
+       /* Switch back to kernel console on panic */
+       /* multi card linked list maybe */
+       if (list_empty(&kernel_fb_helper_list)) {
+               dev_info(fb_helper->dev->dev, "registered panic notifier\n");
+               atomic_notifier_chain_register(&panic_notifier_list,
+                                              &paniced);
+               register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
+       }
+
+       list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
+
+       return 0;
+}
+
+/**
+ * drm_fb_helper_fill_fix - initializes fixed fbdev information
+ * @info: fbdev registered by the helper
+ * @pitch: desired pitch
+ * @depth: desired depth
+ *
+ * Helper to fill in the fixed fbdev information useful for a non-accelerated
+ * fbdev emulations. Drivers which support acceleration methods which impose
+ * additional constraints need to set up their own limits.
+ *
+ * Drivers should call this (or their equivalent setup code) from their
+ * ->fb_probe callback.
+ */
+void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
+                           uint32_t depth)
+{
+       info->fix.type = FB_TYPE_PACKED_PIXELS;
+       info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
+               FB_VISUAL_TRUECOLOR;
+       info->fix.mmio_start = 0;
+       info->fix.mmio_len = 0;
+       info->fix.type_aux = 0;
+       info->fix.xpanstep = 1; /* doing it in hw */
+       info->fix.ypanstep = 1; /* doing it in hw */
+       info->fix.ywrapstep = 0;
+       info->fix.accel = FB_ACCEL_NONE;
+
+       info->fix.line_length = pitch;
+       return;
+}
+EXPORT_SYMBOL(drm_fb_helper_fill_fix);
+
+/**
+ * drm_fb_helper_fill_var - initalizes variable fbdev information
+ * @info: fbdev instance to set up
+ * @fb_helper: fb helper instance to use as template
+ * @fb_width: desired fb width
+ * @fb_height: desired fb height
+ *
+ * Sets up the variable fbdev metainformation from the given fb helper instance
+ * and the drm framebuffer allocated in fb_helper->fb.
+ *
+ * Drivers should call this (or their equivalent setup code) from their
+ * ->fb_probe callback after having allocated the fbdev backing
+ * storage framebuffer.
+ */
+void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
+                           uint32_t fb_width, uint32_t fb_height)
+{
+       struct drm_framebuffer *fb = fb_helper->fb;
+       info->pseudo_palette = fb_helper->pseudo_palette;
+       info->var.xres_virtual = fb->width;
+       info->var.yres_virtual = fb->height;
+       info->var.bits_per_pixel = fb->bits_per_pixel;
+       info->var.accel_flags = FB_ACCELF_TEXT;
+       info->var.xoffset = 0;
+       info->var.yoffset = 0;
+       info->var.activate = FB_ACTIVATE_NOW;
+       info->var.height = -1;
+       info->var.width = -1;
+
+       switch (fb->depth) {
+       case 8:
+               info->var.red.offset = 0;
+               info->var.green.offset = 0;
+               info->var.blue.offset = 0;
+               info->var.red.length = 8; /* 8bit DAC */
+               info->var.green.length = 8;
+               info->var.blue.length = 8;
+               info->var.transp.offset = 0;
+               info->var.transp.length = 0;
+               break;
+       case 15:
+               info->var.red.offset = 10;
+               info->var.green.offset = 5;
+               info->var.blue.offset = 0;
+               info->var.red.length = 5;
+               info->var.green.length = 5;
+               info->var.blue.length = 5;
+               info->var.transp.offset = 15;
+               info->var.transp.length = 1;
+               break;
+       case 16:
+               info->var.red.offset = 11;
+               info->var.green.offset = 5;
+               info->var.blue.offset = 0;
+               info->var.red.length = 5;
+               info->var.green.length = 6;
+               info->var.blue.length = 5;
+               info->var.transp.offset = 0;
+               break;
+       case 24:
+               info->var.red.offset = 16;
+               info->var.green.offset = 8;
+               info->var.blue.offset = 0;
+               info->var.red.length = 8;
+               info->var.green.length = 8;
+               info->var.blue.length = 8;
+               info->var.transp.offset = 0;
+               info->var.transp.length = 0;
+               break;
+       case 32:
+               info->var.red.offset = 16;
+               info->var.green.offset = 8;
+               info->var.blue.offset = 0;
+               info->var.red.length = 8;
+               info->var.green.length = 8;
+               info->var.blue.length = 8;
+               info->var.transp.offset = 24;
+               info->var.transp.length = 8;
+               break;
+       default:
+               break;
+       }
+
+       info->var.xres = fb_width;
+       info->var.yres = fb_height;
+}
+EXPORT_SYMBOL(drm_fb_helper_fill_var);
+
+static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper,
+                                              uint32_t maxX,
+                                              uint32_t maxY)
+{
+       struct drm_connector *connector;
+       int count = 0;
+       int i;
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               connector = fb_helper->connector_info[i]->connector;
+               count += connector->funcs->fill_modes(connector, maxX, maxY);
+       }
+
+       return count;
+}
+
+struct drm_display_mode *drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector, int width, int height)
+{
+       struct drm_display_mode *mode;
+
+       list_for_each_entry(mode, &fb_connector->connector->modes, head) {
+               if (mode->hdisplay > width ||
+                   mode->vdisplay > height)
+                       continue;
+               if (mode->type & DRM_MODE_TYPE_PREFERRED)
+                       return mode;
+       }
+       return NULL;
+}
+EXPORT_SYMBOL(drm_has_preferred_mode);
+
+static bool drm_has_cmdline_mode(struct drm_fb_helper_connector *fb_connector)
+{
+       return fb_connector->connector->cmdline_mode.specified;
+}
+
+struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
+                                                     int width, int height)
+{
+       struct drm_cmdline_mode *cmdline_mode;
+       struct drm_display_mode *mode;
+       bool prefer_non_interlace;
+
+       cmdline_mode = &fb_helper_conn->connector->cmdline_mode;
+       if (cmdline_mode->specified == false)
+               return NULL;
+
+       /* attempt to find a matching mode in the list of modes
+        *  we have gotten so far, if not add a CVT mode that conforms
+        */
+       if (cmdline_mode->rb || cmdline_mode->margins)
+               goto create_mode;
+
+       prefer_non_interlace = !cmdline_mode->interlace;
+again:
+       list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
+               /* check width/height */
+               if (mode->hdisplay != cmdline_mode->xres ||
+                   mode->vdisplay != cmdline_mode->yres)
+                       continue;
+
+               if (cmdline_mode->refresh_specified) {
+                       if (mode->vrefresh != cmdline_mode->refresh)
+                               continue;
+               }
+
+               if (cmdline_mode->interlace) {
+                       if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
+                               continue;
+               } else if (prefer_non_interlace) {
+                       if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+                               continue;
+               }
+               return mode;
+       }
+
+       if (prefer_non_interlace) {
+               prefer_non_interlace = false;
+               goto again;
+       }
+
+create_mode:
+       mode = drm_mode_create_from_cmdline_mode(fb_helper_conn->connector->dev,
+                                                cmdline_mode);
+       list_add(&mode->head, &fb_helper_conn->connector->modes);
+       return mode;
+}
+EXPORT_SYMBOL(drm_pick_cmdline_mode);
+
+static bool drm_connector_enabled(struct drm_connector *connector, bool strict)
+{
+       bool enable;
+
+       if (strict)
+               enable = connector->status == connector_status_connected;
+       else
+               enable = connector->status != connector_status_disconnected;
+
+       return enable;
+}
+
+static void drm_enable_connectors(struct drm_fb_helper *fb_helper,
+                                 bool *enabled)
+{
+       bool any_enabled = false;
+       struct drm_connector *connector;
+       int i = 0;
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               connector = fb_helper->connector_info[i]->connector;
+               enabled[i] = drm_connector_enabled(connector, true);
+               DRM_DEBUG_KMS("connector %d enabled? %s\n", connector->base.id,
+                         enabled[i] ? "yes" : "no");
+               any_enabled |= enabled[i];
+       }
+
+       if (any_enabled)
+               return;
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               connector = fb_helper->connector_info[i]->connector;
+               enabled[i] = drm_connector_enabled(connector, false);
+       }
+}
+
+static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
+                             struct drm_display_mode **modes,
+                             struct drm_fb_offset *offsets,
+                             bool *enabled, int width, int height)
+{
+       int count, i, j;
+       bool can_clone = false;
+       struct drm_fb_helper_connector *fb_helper_conn;
+       struct drm_display_mode *dmt_mode, *mode;
+
+       /* only contemplate cloning in the single crtc case */
+       if (fb_helper->crtc_count > 1)
+               return false;
+
+       count = 0;
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               if (enabled[i])
+                       count++;
+       }
+
+       /* only contemplate cloning if more than one connector is enabled */
+       if (count <= 1)
+               return false;
+
+       /* check the command line or if nothing common pick 1024x768 */
+       can_clone = true;
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               if (!enabled[i])
+                       continue;
+               fb_helper_conn = fb_helper->connector_info[i];
+               modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
+               if (!modes[i]) {
+                       can_clone = false;
+                       break;
+               }
+               for (j = 0; j < i; j++) {
+                       if (!enabled[j])
+                               continue;
+                       if (!drm_mode_equal(modes[j], modes[i]))
+                               can_clone = false;
+               }
+       }
+
+       if (can_clone) {
+               DRM_DEBUG_KMS("can clone using command line\n");
+               return true;
+       }
+
+       /* try and find a 1024x768 mode on each connector */
+       can_clone = true;
+       dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60, false);
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+
+               if (!enabled[i])
+                       continue;
+
+               fb_helper_conn = fb_helper->connector_info[i];
+               list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
+                       if (drm_mode_equal(mode, dmt_mode))
+                               modes[i] = mode;
+               }
+               if (!modes[i])
+                       can_clone = false;
+       }
+
+       if (can_clone) {
+               DRM_DEBUG_KMS("can clone using 1024x768\n");
+               return true;
+       }
+       DRM_INFO("kms: can't enable cloning when we probably wanted to.\n");
+       return false;
+}
+
+static int drm_get_tile_offsets(struct drm_fb_helper *fb_helper,
+                               struct drm_display_mode **modes,
+                               struct drm_fb_offset *offsets,
+                               int idx,
+                               int h_idx, int v_idx)
+{
+       struct drm_fb_helper_connector *fb_helper_conn;
+       int i;
+       int hoffset = 0, voffset = 0;
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               fb_helper_conn = fb_helper->connector_info[i];
+               if (!fb_helper_conn->connector->has_tile)
+                       continue;
+
+               if (!modes[i] && (h_idx || v_idx)) {
+                       DRM_DEBUG_KMS("no modes for connector tiled %d %d\n", i,
+                                     fb_helper_conn->connector->base.id);
+                       continue;
+               }
+               if (fb_helper_conn->connector->tile_h_loc < h_idx)
+                       hoffset += modes[i]->hdisplay;
+
+               if (fb_helper_conn->connector->tile_v_loc < v_idx)
+                       voffset += modes[i]->vdisplay;
+       }
+       offsets[idx].x = hoffset;
+       offsets[idx].y = voffset;
+       DRM_DEBUG_KMS("returned %d %d for %d %d\n", hoffset, voffset, h_idx, v_idx);
+       return 0;
+}
+
+static bool drm_target_preferred(struct drm_fb_helper *fb_helper,
+                                struct drm_display_mode **modes,
+                                struct drm_fb_offset *offsets,
+                                bool *enabled, int width, int height)
+{
+       struct drm_fb_helper_connector *fb_helper_conn;
+       int i;
+       uint64_t conn_configured = 0, mask;
+       int tile_pass = 0;
+       mask = (1 << fb_helper->connector_count) - 1;
+retry:
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               fb_helper_conn = fb_helper->connector_info[i];
+
+               if (conn_configured & (1 << i))
+                       continue;
+
+               if (enabled[i] == false) {
+                       conn_configured |= (1 << i);
+                       continue;
+               }
+
+               /* first pass over all the untiled connectors */
+               if (tile_pass == 0 && fb_helper_conn->connector->has_tile)
+                       continue;
+
+               if (tile_pass == 1) {
+                       if (fb_helper_conn->connector->tile_h_loc != 0 ||
+                           fb_helper_conn->connector->tile_v_loc != 0)
+                               continue;
+
+               } else {
+                       if (fb_helper_conn->connector->tile_h_loc != tile_pass -1 &&
+                           fb_helper_conn->connector->tile_v_loc != tile_pass - 1)
+                       /* if this tile_pass doesn't cover any of the tiles - keep going */
+                               continue;
+
+                       /* find the tile offsets for this pass - need
+                          to find all tiles left and above */
+                       drm_get_tile_offsets(fb_helper, modes, offsets,
+                                            i, fb_helper_conn->connector->tile_h_loc, fb_helper_conn->connector->tile_v_loc);
+               }
+               DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
+                             fb_helper_conn->connector->base.id);
+
+               /* got for command line mode first */
+               modes[i] = drm_pick_cmdline_mode(fb_helper_conn, width, height);
+               if (!modes[i]) {
+                       DRM_DEBUG_KMS("looking for preferred mode on connector %d %d\n",
+                                     fb_helper_conn->connector->base.id, fb_helper_conn->connector->tile_group ? fb_helper_conn->connector->tile_group->id : 0);
+                       modes[i] = drm_has_preferred_mode(fb_helper_conn, width, height);
+               }
+               /* No preferred modes, pick one off the list */
+               if (!modes[i] && !list_empty(&fb_helper_conn->connector->modes)) {
+                       list_for_each_entry(modes[i], &fb_helper_conn->connector->modes, head)
+                               break;
+               }
+               DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
+                         "none");
+               conn_configured |= (1 << i);
+       }
+
+       if ((conn_configured & mask) != mask) {
+               tile_pass++;
+               goto retry;
+       }
+       return true;
+}
+
+static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
+                         struct drm_fb_helper_crtc **best_crtcs,
+                         struct drm_display_mode **modes,
+                         int n, int width, int height)
+{
+       int c, o;
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_connector *connector;
+       const struct drm_connector_helper_funcs *connector_funcs;
+       struct drm_encoder *encoder;
+       int my_score, best_score, score;
+       struct drm_fb_helper_crtc **crtcs, *crtc;
+       struct drm_fb_helper_connector *fb_helper_conn;
+
+       if (n == fb_helper->connector_count)
+               return 0;
+
+       fb_helper_conn = fb_helper->connector_info[n];
+       connector = fb_helper_conn->connector;
+
+       best_crtcs[n] = NULL;
+       best_score = drm_pick_crtcs(fb_helper, best_crtcs, modes, n+1, width, height);
+       if (modes[n] == NULL)
+               return best_score;
+
+       crtcs = kzalloc(dev->mode_config.num_connector *
+                       sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
+       if (!crtcs)
+               return best_score;
+
+       my_score = 1;
+       if (connector->status == connector_status_connected)
+               my_score++;
+       if (drm_has_cmdline_mode(fb_helper_conn))
+               my_score++;
+       if (drm_has_preferred_mode(fb_helper_conn, width, height))
+               my_score++;
+
+       connector_funcs = connector->helper_private;
+       encoder = connector_funcs->best_encoder(connector);
+       if (!encoder)
+               goto out;
+
+       /* select a crtc for this connector and then attempt to configure
+          remaining connectors */
+       for (c = 0; c < fb_helper->crtc_count; c++) {
+               crtc = &fb_helper->crtc_info[c];
+
+               if ((encoder->possible_crtcs & (1 << c)) == 0)
+                       continue;
+
+               for (o = 0; o < n; o++)
+                       if (best_crtcs[o] == crtc)
+                               break;
+
+               if (o < n) {
+                       /* ignore cloning unless only a single crtc */
+                       if (fb_helper->crtc_count > 1)
+                               continue;
+
+                       if (!drm_mode_equal(modes[o], modes[n]))
+                               continue;
+               }
+
+               crtcs[n] = crtc;
+               memcpy(crtcs, best_crtcs, n * sizeof(struct drm_fb_helper_crtc *));
+               score = my_score + drm_pick_crtcs(fb_helper, crtcs, modes, n + 1,
+                                                 width, height);
+               if (score > best_score) {
+                       best_score = score;
+                       memcpy(best_crtcs, crtcs,
+                              dev->mode_config.num_connector *
+                              sizeof(struct drm_fb_helper_crtc *));
+               }
+       }
+out:
+       kfree(crtcs);
+       return best_score;
+}
+
+static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       struct drm_fb_helper_crtc **crtcs;
+       struct drm_display_mode **modes;
+       struct drm_fb_offset *offsets;
+       struct drm_mode_set *modeset;
+       bool *enabled;
+       int width, height;
+       int i;
+
+       DRM_DEBUG_KMS("\n");
+
+       width = dev->mode_config.max_width;
+       height = dev->mode_config.max_height;
+
+       crtcs = kcalloc(dev->mode_config.num_connector,
+                       sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
+       modes = kcalloc(dev->mode_config.num_connector,
+                       sizeof(struct drm_display_mode *), GFP_KERNEL);
+       offsets = kcalloc(dev->mode_config.num_connector,
+                         sizeof(struct drm_fb_offset), GFP_KERNEL);
+       enabled = kcalloc(dev->mode_config.num_connector,
+                         sizeof(bool), GFP_KERNEL);
+       if (!crtcs || !modes || !enabled || !offsets) {
+               DRM_ERROR("Memory allocation failed\n");
+               goto out;
+       }
+
+
+       drm_enable_connectors(fb_helper, enabled);
+
+       if (!(fb_helper->funcs->initial_config &&
+             fb_helper->funcs->initial_config(fb_helper, crtcs, modes,
+                                              offsets,
+                                              enabled, width, height))) {
+               memset(modes, 0, dev->mode_config.num_connector*sizeof(modes[0]));
+               memset(crtcs, 0, dev->mode_config.num_connector*sizeof(crtcs[0]));
+               memset(offsets, 0, dev->mode_config.num_connector*sizeof(offsets[0]));
+
+               if (!drm_target_cloned(fb_helper, modes, offsets,
+                                      enabled, width, height) &&
+                   !drm_target_preferred(fb_helper, modes, offsets,
+                                         enabled, width, height))
+                       DRM_ERROR("Unable to find initial modes\n");
+
+               DRM_DEBUG_KMS("picking CRTCs for %dx%d config\n",
+                             width, height);
+
+               drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height);
+       }
+
+       /* need to set the modesets up here for use later */
+       /* fill out the connector<->crtc mappings into the modesets */
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               modeset = &fb_helper->crtc_info[i].mode_set;
+               modeset->num_connectors = 0;
+               modeset->fb = NULL;
+       }
+
+       for (i = 0; i < fb_helper->connector_count; i++) {
+               struct drm_display_mode *mode = modes[i];
+               struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
+               struct drm_fb_offset *offset = &offsets[i];
+               modeset = &fb_crtc->mode_set;
+
+               if (mode && fb_crtc) {
+                       DRM_DEBUG_KMS("desired mode %s set on crtc %d (%d,%d)\n",
+                                     mode->name, fb_crtc->mode_set.crtc->base.id, offset->x, offset->y);
+                       fb_crtc->desired_mode = mode;
+                       fb_crtc->x = offset->x;
+                       fb_crtc->y = offset->y;
+                       if (modeset->mode)
+                               drm_mode_destroy(dev, modeset->mode);
+                       modeset->mode = drm_mode_duplicate(dev,
+                                                          fb_crtc->desired_mode);
+                       modeset->connectors[modeset->num_connectors++] = fb_helper->connector_info[i]->connector;
+                       modeset->fb = fb_helper->fb;
+                       modeset->x = offset->x;
+                       modeset->y = offset->y;
+               }
+       }
+
+       /* Clear out any old modes if there are no more connected outputs. */
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               modeset = &fb_helper->crtc_info[i].mode_set;
+               if (modeset->num_connectors == 0) {
+                       BUG_ON(modeset->fb);
+                       if (modeset->mode)
+                               drm_mode_destroy(dev, modeset->mode);
+                       modeset->mode = NULL;
+               }
+       }
+out:
+       kfree(crtcs);
+       kfree(modes);
+       kfree(offsets);
+       kfree(enabled);
+}
+
+/**
+ * drm_fb_helper_initial_config - setup a sane initial connector configuration
+ * @fb_helper: fb_helper device struct
+ * @bpp_sel: bpp value to use for the framebuffer configuration
+ *
+ * Scans the CRTCs and connectors and tries to put together an initial setup.
+ * At the moment, this is a cloned configuration across all heads with
+ * a new framebuffer object as the backing store.
+ *
+ * Note that this also registers the fbdev and so allows userspace to call into
+ * the driver through the fbdev interfaces.
+ *
+ * This function will call down into the ->fb_probe callback to let
+ * the driver allocate and initialize the fbdev info structure and the drm
+ * framebuffer used to back the fbdev. drm_fb_helper_fill_var() and
+ * drm_fb_helper_fill_fix() are provided as helpers to setup simple default
+ * values for the fbdev info structure.
+ *
+ * RETURNS:
+ * Zero if everything went ok, nonzero otherwise.
+ */
+int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
+{
+       struct drm_device *dev = fb_helper->dev;
+       int count = 0;
+
+       mutex_lock(&dev->mode_config.mutex);
+       count = drm_fb_helper_probe_connector_modes(fb_helper,
+                                                   dev->mode_config.max_width,
+                                                   dev->mode_config.max_height);
+       mutex_unlock(&dev->mode_config.mutex);
+       /*
+        * we shouldn't end up with no modes here.
+        */
+       if (count == 0)
+               dev_info(fb_helper->dev->dev, "No connectors reported connected with modes\n");
+
+       drm_setup_crtcs(fb_helper);
+
+       return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
+}
+EXPORT_SYMBOL(drm_fb_helper_initial_config);
+
+/**
+ * drm_fb_helper_hotplug_event - respond to a hotplug notification by
+ *                               probing all the outputs attached to the fb
+ * @fb_helper: the drm_fb_helper
+ *
+ * Scan the connectors attached to the fb_helper and try to put together a
+ * setup after *notification of a change in output configuration.
+ *
+ * Called at runtime, takes the mode config locks to be able to check/change the
+ * modeset configuration. Must be run from process context (which usually means
+ * either the output polling work or a work item launched from the driver's
+ * hotplug interrupt).
+ *
+ * Note that drivers may call this even before calling
+ * drm_fb_helper_initial_config but only aftert drm_fb_helper_init. This allows
+ * for a race-free fbcon setup and will make sure that the fbdev emulation will
+ * not miss any hotplug events.
+ *
+ * RETURNS:
+ * 0 on success and a non-zero error code otherwise.
+ */
+int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
+{
+       struct drm_device *dev = fb_helper->dev;
+       u32 max_width, max_height;
+
+       mutex_lock(&fb_helper->dev->mode_config.mutex);
+       if (!fb_helper->fb || !drm_fb_helper_is_bound(fb_helper)) {
+               fb_helper->delayed_hotplug = true;
+               mutex_unlock(&fb_helper->dev->mode_config.mutex);
+               return 0;
+       }
+       DRM_DEBUG_KMS("\n");
+
+       max_width = fb_helper->fb->width;
+       max_height = fb_helper->fb->height;
+
+       drm_fb_helper_probe_connector_modes(fb_helper, max_width, max_height);
+       mutex_unlock(&fb_helper->dev->mode_config.mutex);
+
+       drm_modeset_lock_all(dev);
+       drm_setup_crtcs(fb_helper);
+       drm_modeset_unlock_all(dev);
+       drm_fb_helper_set_par(fb_helper->fbdev);
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
+
+/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
+ * but the module doesn't depend on any fb console symbols.  At least
+ * attempt to load fbcon to avoid leaving the system without a usable console.
+ */
+#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
+static int __init drm_fb_helper_modinit(void)
+{
+       const char *name = "fbcon";
+       struct module *fbcon;
+
+       mutex_lock(&module_mutex);
+       fbcon = find_module(name);
+       mutex_unlock(&module_mutex);
+
+       if (!fbcon)
+               request_module_nowait(name);
+       return 0;
+}
+
+module_init(drm_fb_helper_modinit);
+#endif