321 lines
9.1 KiB
C
321 lines
9.1 KiB
C
/*
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* Copyright (c) 2014 Samsung Electronics Co., Ltd
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sub license,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial portions
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* of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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#include <linux/err.h>
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#include <linux/module.h>
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#include <drm/drm_crtc.h>
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#include "drm/drmP.h"
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/**
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* DOC: overview
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*
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* struct &drm_bridge represents a device that hangs on to an encoder. These are
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* handy when a regular &drm_encoder entity isn't enough to represent the entire
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* encoder chain.
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*
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* A bridge is always attached to a single &drm_encoder at a time, but can be
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* either connected to it directly, or through an intermediate bridge:
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*
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* encoder ---> bridge B ---> bridge A
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*
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* Here, the output of the encoder feeds to bridge B, and that furthers feeds to
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* bridge A.
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*
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* The driver using the bridge is responsible to make the associations between
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* the encoder and bridges. Once these links are made, the bridges will
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* participate along with encoder functions to perform mode_set/enable/disable
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* through the ops provided in &drm_bridge_funcs.
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*
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* drm_bridge, like drm_panel, aren't drm_mode_object entities like planes,
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* CRTCs, encoders or connectors and hence are not visible to userspace. They
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* just provide additional hooks to get the desired output at the end of the
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* encoder chain.
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*
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* Bridges can also be chained up using the next pointer in struct &drm_bridge.
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*
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* Both legacy CRTC helpers and the new atomic modeset helpers support bridges.
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*/
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static DEFINE_MUTEX(bridge_lock);
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static LIST_HEAD(bridge_list);
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/**
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* drm_bridge_add - add the given bridge to the global bridge list
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*
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* @bridge: bridge control structure
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*
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* RETURNS:
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* Unconditionally returns Zero.
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*/
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int drm_bridge_add(struct drm_bridge *bridge)
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{
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mutex_lock(&bridge_lock);
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list_add_tail(&bridge->list, &bridge_list);
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mutex_unlock(&bridge_lock);
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return 0;
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}
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EXPORT_SYMBOL(drm_bridge_add);
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/**
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* drm_bridge_remove - remove the given bridge from the global bridge list
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*
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* @bridge: bridge control structure
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*/
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void drm_bridge_remove(struct drm_bridge *bridge)
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{
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mutex_lock(&bridge_lock);
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list_del_init(&bridge->list);
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mutex_unlock(&bridge_lock);
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}
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EXPORT_SYMBOL(drm_bridge_remove);
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/**
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* drm_bridge_attach - associate given bridge to our DRM device
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*
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* @dev: DRM device
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* @bridge: bridge control structure
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*
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* called by a kms driver to link one of our encoder/bridge to the given
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* bridge.
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*
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* Note that setting up links between the bridge and our encoder/bridge
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* objects needs to be handled by the kms driver itself
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*
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* RETURNS:
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* Zero on success, error code on failure
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*/
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int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge)
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{
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if (!dev || !bridge)
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return -EINVAL;
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if (bridge->dev)
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return -EBUSY;
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bridge->dev = dev;
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if (bridge->funcs->attach)
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return bridge->funcs->attach(bridge);
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return 0;
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}
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EXPORT_SYMBOL(drm_bridge_attach);
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/**
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* DOC: bridge callbacks
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*
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* The &drm_bridge_funcs ops are populated by the bridge driver. The DRM
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* internals (atomic and CRTC helpers) use the helpers defined in drm_bridge.c
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* These helpers call a specific &drm_bridge_funcs op for all the bridges
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* during encoder configuration.
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*
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* For detailed specification of the bridge callbacks see &drm_bridge_funcs.
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*/
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/**
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* drm_bridge_mode_fixup - fixup proposed mode for all bridges in the
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* encoder chain
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* @bridge: bridge control structure
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* @mode: desired mode to be set for the bridge
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* @adjusted_mode: updated mode that works for this bridge
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*
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* Calls ->mode_fixup() &drm_bridge_funcs op for all the bridges in the
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* encoder chain, starting from the first bridge to the last.
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*
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* Note: the bridge passed should be the one closest to the encoder
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*
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* RETURNS:
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* true on success, false on failure
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*/
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bool drm_bridge_mode_fixup(struct drm_bridge *bridge,
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const struct drm_display_mode *mode,
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struct drm_display_mode *adjusted_mode)
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{
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bool ret = true;
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if (!bridge)
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return true;
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if (bridge->funcs->mode_fixup)
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ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode);
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ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode);
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return ret;
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}
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EXPORT_SYMBOL(drm_bridge_mode_fixup);
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/**
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* drm_bridge_disable - calls ->disable() &drm_bridge_funcs op for all
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* bridges in the encoder chain.
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* @bridge: bridge control structure
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*
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* Calls ->disable() &drm_bridge_funcs op for all the bridges in the encoder
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* chain, starting from the last bridge to the first. These are called before
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* calling the encoder's prepare op.
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*
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* Note: the bridge passed should be the one closest to the encoder
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*/
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void drm_bridge_disable(struct drm_bridge *bridge)
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{
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if (!bridge)
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return;
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drm_bridge_disable(bridge->next);
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if (bridge->funcs->disable)
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bridge->funcs->disable(bridge);
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}
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EXPORT_SYMBOL(drm_bridge_disable);
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/**
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* drm_bridge_post_disable - calls ->post_disable() &drm_bridge_funcs op for
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* all bridges in the encoder chain.
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* @bridge: bridge control structure
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*
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* Calls ->post_disable() &drm_bridge_funcs op for all the bridges in the
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* encoder chain, starting from the first bridge to the last. These are called
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* after completing the encoder's prepare op.
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*
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* Note: the bridge passed should be the one closest to the encoder
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*/
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void drm_bridge_post_disable(struct drm_bridge *bridge)
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{
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if (!bridge)
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return;
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if (bridge->funcs->post_disable)
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bridge->funcs->post_disable(bridge);
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drm_bridge_post_disable(bridge->next);
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}
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EXPORT_SYMBOL(drm_bridge_post_disable);
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/**
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* drm_bridge_mode_set - set proposed mode for all bridges in the
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* encoder chain
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* @bridge: bridge control structure
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* @mode: desired mode to be set for the bridge
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* @adjusted_mode: updated mode that works for this bridge
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*
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* Calls ->mode_set() &drm_bridge_funcs op for all the bridges in the
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* encoder chain, starting from the first bridge to the last.
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*
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* Note: the bridge passed should be the one closest to the encoder
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*/
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void drm_bridge_mode_set(struct drm_bridge *bridge,
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struct drm_display_mode *mode,
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struct drm_display_mode *adjusted_mode)
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{
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if (!bridge)
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return;
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if (bridge->funcs->mode_set)
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bridge->funcs->mode_set(bridge, mode, adjusted_mode);
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drm_bridge_mode_set(bridge->next, mode, adjusted_mode);
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}
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EXPORT_SYMBOL(drm_bridge_mode_set);
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/**
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* drm_bridge_pre_enable - calls ->pre_enable() &drm_bridge_funcs op for all
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* bridges in the encoder chain.
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* @bridge: bridge control structure
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*
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* Calls ->pre_enable() &drm_bridge_funcs op for all the bridges in the encoder
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* chain, starting from the last bridge to the first. These are called
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* before calling the encoder's commit op.
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*
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* Note: the bridge passed should be the one closest to the encoder
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*/
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void drm_bridge_pre_enable(struct drm_bridge *bridge)
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{
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if (!bridge)
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return;
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drm_bridge_pre_enable(bridge->next);
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if (bridge->funcs->pre_enable)
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bridge->funcs->pre_enable(bridge);
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}
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EXPORT_SYMBOL(drm_bridge_pre_enable);
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/**
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* drm_bridge_enable - calls ->enable() &drm_bridge_funcs op for all bridges
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* in the encoder chain.
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* @bridge: bridge control structure
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*
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* Calls ->enable() &drm_bridge_funcs op for all the bridges in the encoder
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* chain, starting from the first bridge to the last. These are called
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* after completing the encoder's commit op.
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*
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* Note that the bridge passed should be the one closest to the encoder
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*/
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void drm_bridge_enable(struct drm_bridge *bridge)
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{
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if (!bridge)
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return;
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if (bridge->funcs->enable)
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bridge->funcs->enable(bridge);
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drm_bridge_enable(bridge->next);
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}
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EXPORT_SYMBOL(drm_bridge_enable);
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#ifdef CONFIG_OF
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/**
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* of_drm_find_bridge - find the bridge corresponding to the device node in
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* the global bridge list
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*
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* @np: device node
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*
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* RETURNS:
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* drm_bridge control struct on success, NULL on failure
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*/
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struct drm_bridge *of_drm_find_bridge(struct device_node *np)
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{
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struct drm_bridge *bridge;
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mutex_lock(&bridge_lock);
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list_for_each_entry(bridge, &bridge_list, list) {
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if (bridge->of_node == np) {
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mutex_unlock(&bridge_lock);
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return bridge;
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}
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}
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mutex_unlock(&bridge_lock);
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return NULL;
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}
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EXPORT_SYMBOL(of_drm_find_bridge);
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#endif
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MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
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MODULE_DESCRIPTION("DRM bridge infrastructure");
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MODULE_LICENSE("GPL and additional rights");
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