DRM: add mode setting support

Add mode setting support to the DRM layer.

This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace.  It was
motivated by several factors:
  - the fb layer's APIs aren't suited for anything but simple
    configurations
  - coordination between the fb layer, DRM layer, and various userspace
    drivers is poor to non-existent (radeonfb excepted)
  - user level mode setting drivers makes displaying panic & oops
    messages more difficult
  - suspend/resume of graphics state is possible in many more
    configurations with kernel level support

This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.

Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com>

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
new file mode 100644
index 0000000..a341828
--- /dev/null
+++ b/include/drm/drm_crtc_helper.h
@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2006 Keith Packard
+ * Copyright © 2007-2008 Dave Airlie
+ * Copyright © 2007-2008 Intel Corporation
+ *   Jesse Barnes <jesse.barnes@intel.com>
+ *
+ * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ */
+
+/*
+ * The DRM mode setting helper functions are common code for drivers to use if
+ * they wish.  Drivers are not forced to use this code in their
+ * implementations but it would be useful if they code they do use at least
+ * provides a consistent interface and operation to userspace
+ */
+
+#ifndef __DRM_CRTC_HELPER_H__
+#define __DRM_CRTC_HELPER_H__
+
+#include <linux/i2c.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/idr.h>
+
+#include <linux/fb.h>
+
+struct drm_crtc_helper_funcs {
+	/*
+	 * Control power levels on the CRTC.  If the mode passed in is
+	 * unsupported, the provider must use the next lowest power level.
+	 */
+	void (*dpms)(struct drm_crtc *crtc, int mode);
+	void (*prepare)(struct drm_crtc *crtc);
+	void (*commit)(struct drm_crtc *crtc);
+
+	/* Provider can fixup or change mode timings before modeset occurs */
+	bool (*mode_fixup)(struct drm_crtc *crtc,
+			   struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+	/* Actually set the mode */
+	void (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode, int x, int y);
+
+	/* Move the crtc on the current fb to the given position *optional* */
+	void (*mode_set_base)(struct drm_crtc *crtc, int x, int y);
+};
+
+struct drm_encoder_helper_funcs {
+	void (*dpms)(struct drm_encoder *encoder, int mode);
+	void (*save)(struct drm_encoder *encoder);
+	void (*restore)(struct drm_encoder *encoder);
+
+	bool (*mode_fixup)(struct drm_encoder *encoder,
+			   struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+	void (*prepare)(struct drm_encoder *encoder);
+	void (*commit)(struct drm_encoder *encoder);
+	void (*mode_set)(struct drm_encoder *encoder,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode);
+	/* detect for DAC style encoders */
+	enum drm_connector_status (*detect)(struct drm_encoder *encoder,
+					    struct drm_connector *connector);
+};
+
+struct drm_connector_helper_funcs {
+	int (*get_modes)(struct drm_connector *connector);
+	int (*mode_valid)(struct drm_connector *connector,
+			  struct drm_display_mode *mode);
+	struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
+};
+
+extern void drm_helper_probe_single_connector_modes(struct drm_connector *connector, uint32_t maxX, uint32_t maxY);
+extern void drm_helper_disable_unused_functions(struct drm_device *dev);
+extern int drm_helper_hotplug_stage_two(struct drm_device *dev);
+extern bool drm_helper_initial_config(struct drm_device *dev, bool can_grow);
+extern int drm_crtc_helper_set_config(struct drm_mode_set *set);
+extern bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
+				     struct drm_display_mode *mode,
+				     int x, int y);
+extern bool drm_helper_crtc_in_use(struct drm_crtc *crtc);
+
+extern int drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
+					  struct drm_mode_fb_cmd *mode_cmd);
+
+static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
+				       const struct drm_crtc_helper_funcs *funcs)
+{
+	crtc->helper_private = (void *)funcs;
+}
+
+static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
+					  const struct drm_encoder_helper_funcs *funcs)
+{
+	encoder->helper_private = (void *)funcs;
+}
+
+static inline void drm_connector_helper_add(struct drm_connector *connector,
+					    const struct drm_connector_helper_funcs *funcs)
+{
+	connector->helper_private = (void *)funcs;
+}
+
+extern int drm_helper_resume_force_mode(struct drm_device *dev);
+#endif