1 files changed, 218 insertions, 0 deletions
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
new file mode 100644
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+++ b/include/drm/drm_bridge.h
@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * 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.
+ */
+
+#ifndef __DRM_BRIDGE_H__
+#define __DRM_BRIDGE_H__
+
+#include <linux/list.h>
+#include <linux/ctype.h>
+#include <drm/drm_mode_object.h>
+#include <drm/drm_modes.h>
+
+struct drm_bridge;
+
+/**
+ * struct drm_bridge_funcs - drm_bridge control functions
+ */
+struct drm_bridge_funcs {
+	/**
+	 * @attach:
+	 *
+	 * This callback is invoked whenever our bridge is being attached to a
+	 * &drm_encoder.
+	 *
+	 * The attach callback is optional.
+	 *
+	 * RETURNS:
+	 *
+	 * Zero on success, error code on failure.
+	 */
+	int (*attach)(struct drm_bridge *bridge);
+
+	/**
+	 * @detach:
+	 *
+	 * This callback is invoked whenever our bridge is being detached from a
+	 * &drm_encoder.
+	 *
+	 * The detach callback is optional.
+	 */
+	void (*detach)(struct drm_bridge *bridge);
+
+	/**
+	 * @mode_fixup:
+	 *
+	 * This callback is used to validate and adjust a mode. The paramater
+	 * mode is the display mode that should be fed to the next element in
+	 * the display chain, either the final &drm_connector or the next
+	 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
+	 * requires. It can be modified by this callback and does not need to
+	 * match mode.
+	 *
+	 * This is the only hook that allows a bridge to reject a modeset. If
+	 * this function passes all other callbacks must succeed for this
+	 * configuration.
+	 *
+	 * The mode_fixup callback is optional.
+	 *
+	 * NOTE:
+	 *
+	 * This function is called in the check phase of atomic modesets, which
+	 * can be aborted for any reason (including on userspace's request to
+	 * just check whether a configuration would be possible). Drivers MUST
+	 * NOT touch any persistent state (hardware or software) or data
+	 * structures except the passed in @state parameter.
+	 *
+	 * RETURNS:
+	 *
+	 * True if an acceptable configuration is possible, false if the modeset
+	 * operation should be rejected.
+	 */
+	bool (*mode_fixup)(struct drm_bridge *bridge,
+			   const struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+	/**
+	 * @disable:
+	 *
+	 * This callback should disable the bridge. It is called right before
+	 * the preceding element in the display pipe is disabled. If the
+	 * preceding element is a bridge this means it's called before that
+	 * bridge's ->disable() function. If the preceding element is a
+	 * &drm_encoder it's called right before the encoder's ->disable(),
+	 * ->prepare() or ->dpms() hook from struct &drm_encoder_helper_funcs.
+	 *
+	 * The bridge can assume that the display pipe (i.e. clocks and timing
+	 * signals) feeding it is still running when this callback is called.
+	 *
+	 * The disable callback is optional.
+	 */
+	void (*disable)(struct drm_bridge *bridge);
+
+	/**
+	 * @post_disable:
+	 *
+	 * This callback should disable the bridge. It is called right after
+	 * the preceding element in the display pipe is disabled. If the
+	 * preceding element is a bridge this means it's called after that
+	 * bridge's ->post_disable() function. If the preceding element is a
+	 * &drm_encoder it's called right after the encoder's ->disable(),
+	 * ->prepare() or ->dpms() hook from struct &drm_encoder_helper_funcs.
+	 *
+	 * The bridge must assume that the display pipe (i.e. clocks and timing
+	 * singals) feeding it is no longer running when this callback is
+	 * called.
+	 *
+	 * The post_disable callback is optional.
+	 */
+	void (*post_disable)(struct drm_bridge *bridge);
+
+	/**
+	 * @mode_set:
+	 *
+	 * This callback should set the given mode on the bridge. It is called
+	 * after the ->mode_set() callback for the preceding element in the
+	 * display pipeline has been called already. The display pipe (i.e.
+	 * clocks and timing signals) is off when this function is called.
+	 */
+	void (*mode_set)(struct drm_bridge *bridge,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode);
+	/**
+	 * @pre_enable:
+	 *
+	 * This callback should enable the bridge. It is called right before
+	 * the preceding element in the display pipe is enabled. If the
+	 * preceding element is a bridge this means it's called before that
+	 * bridge's ->pre_enable() function. If the preceding element is a
+	 * &drm_encoder it's called right before the encoder's ->enable(),
+	 * ->commit() or ->dpms() hook from struct &drm_encoder_helper_funcs.
+	 *
+	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
+	 * will not yet be running when this callback is called. The bridge must
+	 * not enable the display link feeding the next bridge in the chain (if
+	 * there is one) when this callback is called.
+	 *
+	 * The pre_enable callback is optional.
+	 */
+	void (*pre_enable)(struct drm_bridge *bridge);
+
+	/**
+	 * @enable:
+	 *
+	 * This callback should enable the bridge. It is called right after
+	 * the preceding element in the display pipe is enabled. If the
+	 * preceding element is a bridge this means it's called after that
+	 * bridge's ->enable() function. If the preceding element is a
+	 * &drm_encoder it's called right after the encoder's ->enable(),
+	 * ->commit() or ->dpms() hook from struct &drm_encoder_helper_funcs.
+	 *
+	 * The bridge can assume that the display pipe (i.e. clocks and timing
+	 * signals) feeding it is running when this callback is called. This
+	 * callback must enable the display link feeding the next bridge in the
+	 * chain if there is one.
+	 *
+	 * The enable callback is optional.
+	 */
+	void (*enable)(struct drm_bridge *bridge);
+};
+
+/**
+ * struct drm_bridge - central DRM bridge control structure
+ * @dev: DRM device this bridge belongs to
+ * @encoder: encoder to which this bridge is connected
+ * @next: the next bridge in the encoder chain
+ * @of_node: device node pointer to the bridge
+ * @list: to keep track of all added bridges
+ * @funcs: control functions
+ * @driver_private: pointer to the bridge driver's internal context
+ */
+struct drm_bridge {
+	struct drm_device *dev;
+	struct drm_encoder *encoder;
+	struct drm_bridge *next;
+#ifdef CONFIG_OF
+	struct device_node *of_node;
+#endif
+	struct list_head list;
+
+	const struct drm_bridge_funcs *funcs;
+	void *driver_private;
+};
+
+int drm_bridge_add(struct drm_bridge *bridge);
+void drm_bridge_remove(struct drm_bridge *bridge);
+struct drm_bridge *of_drm_find_bridge(struct device_node *np);
+int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge);
+void drm_bridge_detach(struct drm_bridge *bridge);
+
+bool drm_bridge_mode_fixup(struct drm_bridge *bridge,
+			const struct drm_display_mode *mode,
+			struct drm_display_mode *adjusted_mode);
+void drm_bridge_disable(struct drm_bridge *bridge);
+void drm_bridge_post_disable(struct drm_bridge *bridge);
+void drm_bridge_mode_set(struct drm_bridge *bridge,
+			struct drm_display_mode *mode,
+			struct drm_display_mode *adjusted_mode);
+void drm_bridge_pre_enable(struct drm_bridge *bridge);
+void drm_bridge_enable(struct drm_bridge *bridge);
+
+#endif