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![Maxime Ripard](/assets/img/avatar_default.png)
Interactions between bridges, panels, MIPI-DSI host and the component framework are not trivial and can lead to probing issues when implementing a display driver. Let's document the various cases we need too consider, and the solution to support all the cases. Signed-off-by: Maxime Ripard <maxime@cerno.tech> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210910101218.1632297-3-maxime@cerno.tech
1300 lines
42 KiB
C
1300 lines
42 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 <linux/mutex.h>
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#include <drm/drm_atomic_state_helper.h>
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#include <drm/drm_bridge.h>
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#include <drm/drm_encoder.h>
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#include <drm/drm_of.h>
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#include <drm/drm_print.h>
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#include "drm_crtc_internal.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 a chain of bridges::
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*
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* [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
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*
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* Here, the output of the encoder feeds to bridge A, and that furthers feeds to
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* bridge B. Bridge chains can be arbitrarily long, and shall be fully linear:
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* Chaining multiple bridges to the output of a bridge, or the same bridge to
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* the output of different bridges, is not supported.
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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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/**
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* DOC: display driver integration
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*
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* Display drivers are responsible for linking encoders with the first bridge
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* in the chains. This is done by acquiring the appropriate bridge with
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* devm_drm_of_get_bridge(). Once acquired, the bridge shall be attached to the
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* encoder with a call to drm_bridge_attach().
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*
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* Bridges are responsible for linking themselves with the next bridge in the
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* chain, if any. This is done the same way as for encoders, with the call to
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* drm_bridge_attach() occurring in the &drm_bridge_funcs.attach operation.
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*
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* Once these links are created, the bridges can participate along with encoder
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* functions to perform mode validation and fixup (through
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* drm_bridge_chain_mode_valid() and drm_atomic_bridge_chain_check()), mode
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* setting (through drm_bridge_chain_mode_set()), enable (through
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* drm_atomic_bridge_chain_pre_enable() and drm_atomic_bridge_chain_enable())
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* and disable (through drm_atomic_bridge_chain_disable() and
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* drm_atomic_bridge_chain_post_disable()). Those functions call the
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* corresponding operations provided in &drm_bridge_funcs in sequence for all
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* bridges in the chain.
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*
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* For display drivers that use the atomic helpers
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* drm_atomic_helper_check_modeset(),
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* drm_atomic_helper_commit_modeset_enables() and
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* drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
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* commit check and commit tail handlers, or through the higher-level
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* drm_atomic_helper_check() and drm_atomic_helper_commit_tail() or
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* drm_atomic_helper_commit_tail_rpm() helpers), this is done transparently and
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* requires no intervention from the driver. For other drivers, the relevant
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* DRM bridge chain functions shall be called manually.
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*
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* Bridges also participate in implementing the &drm_connector at the end of
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* the bridge chain. Display drivers may use the drm_bridge_connector_init()
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* helper to create the &drm_connector, or implement it manually on top of the
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* connector-related operations exposed by the bridge (see the overview
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* documentation of bridge operations for more details).
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*/
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/**
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* DOC: special care dsi
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*
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* The interaction between the bridges and other frameworks involved in
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* the probing of the upstream driver and the bridge driver can be
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* challenging. Indeed, there's multiple cases that needs to be
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* considered:
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*
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* - The upstream driver doesn't use the component framework and isn't a
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* MIPI-DSI host. In this case, the bridge driver will probe at some
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* point and the upstream driver should try to probe again by returning
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* EPROBE_DEFER as long as the bridge driver hasn't probed.
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*
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* - The upstream driver doesn't use the component framework, but is a
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* MIPI-DSI host. The bridge device uses the MIPI-DCS commands to be
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* controlled. In this case, the bridge device is a child of the
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* display device and when it will probe it's assured that the display
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* device (and MIPI-DSI host) is present. The upstream driver will be
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* assured that the bridge driver is connected between the
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* &mipi_dsi_host_ops.attach and &mipi_dsi_host_ops.detach operations.
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* Therefore, it must run mipi_dsi_host_register() in its probe
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* function, and then run drm_bridge_attach() in its
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* &mipi_dsi_host_ops.attach hook.
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*
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* - The upstream driver uses the component framework and is a MIPI-DSI
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* host. The bridge device uses the MIPI-DCS commands to be
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* controlled. This is the same situation than above, and can run
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* mipi_dsi_host_register() in either its probe or bind hooks.
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*
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* - The upstream driver uses the component framework and is a MIPI-DSI
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* host. The bridge device uses a separate bus (such as I2C) to be
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* controlled. In this case, there's no correlation between the probe
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* of the bridge and upstream drivers, so care must be taken to avoid
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* an endless EPROBE_DEFER loop, with each driver waiting for the
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* other to probe.
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*
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* The ideal pattern to cover the last item (and all the others in the
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* MIPI-DSI host driver case) is to split the operations like this:
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*
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* - The MIPI-DSI host driver must run mipi_dsi_host_register() in its
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* probe hook. It will make sure that the MIPI-DSI host sticks around,
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* and that the driver's bind can be called.
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*
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* - In its probe hook, the bridge driver must try to find its MIPI-DSI
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* host, register as a MIPI-DSI device and attach the MIPI-DSI device
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* to its host. The bridge driver is now functional.
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*
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* - In its &struct mipi_dsi_host_ops.attach hook, the MIPI-DSI host can
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* now add its component. Its bind hook will now be called and since
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* the bridge driver is attached and registered, we can now look for
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* and attach it.
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*
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* At this point, we're now certain that both the upstream driver and
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* the bridge driver are functional and we can't have a deadlock-like
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* situation when probing.
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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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void drm_bridge_add(struct drm_bridge *bridge)
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{
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mutex_init(&bridge->hpd_mutex);
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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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}
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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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mutex_destroy(&bridge->hpd_mutex);
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}
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EXPORT_SYMBOL(drm_bridge_remove);
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static struct drm_private_state *
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drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj)
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{
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struct drm_bridge *bridge = drm_priv_to_bridge(obj);
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struct drm_bridge_state *state;
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state = bridge->funcs->atomic_duplicate_state(bridge);
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return state ? &state->base : NULL;
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}
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static void
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drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj,
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struct drm_private_state *s)
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{
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struct drm_bridge_state *state = drm_priv_to_bridge_state(s);
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struct drm_bridge *bridge = drm_priv_to_bridge(obj);
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bridge->funcs->atomic_destroy_state(bridge, state);
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}
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static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
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.atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state,
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.atomic_destroy_state = drm_bridge_atomic_destroy_priv_state,
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};
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/**
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* drm_bridge_attach - attach the bridge to an encoder's chain
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*
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* @encoder: DRM encoder
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* @bridge: bridge to attach
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* @previous: previous bridge in the chain (optional)
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* @flags: DRM_BRIDGE_ATTACH_* flags
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*
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* Called by a kms driver to link the bridge to an encoder's chain. The previous
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* argument specifies the previous bridge in the chain. If NULL, the bridge is
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* linked directly at the encoder's output. Otherwise it is linked at the
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* previous bridge's output.
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*
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* If non-NULL the previous bridge must be already attached by a call to this
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* function.
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*
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* Note that bridges attached to encoders are auto-detached during encoder
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* cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally
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* *not* be balanced with a drm_bridge_detach() in driver code.
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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_encoder *encoder, struct drm_bridge *bridge,
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struct drm_bridge *previous,
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enum drm_bridge_attach_flags flags)
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{
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int ret;
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if (!encoder || !bridge)
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return -EINVAL;
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if (previous && (!previous->dev || previous->encoder != encoder))
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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 = encoder->dev;
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bridge->encoder = encoder;
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if (previous)
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list_add(&bridge->chain_node, &previous->chain_node);
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else
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list_add(&bridge->chain_node, &encoder->bridge_chain);
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if (bridge->funcs->attach) {
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ret = bridge->funcs->attach(bridge, flags);
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if (ret < 0)
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goto err_reset_bridge;
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}
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if (bridge->funcs->atomic_reset) {
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struct drm_bridge_state *state;
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state = bridge->funcs->atomic_reset(bridge);
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if (IS_ERR(state)) {
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ret = PTR_ERR(state);
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goto err_detach_bridge;
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}
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drm_atomic_private_obj_init(bridge->dev, &bridge->base,
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&state->base,
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&drm_bridge_priv_state_funcs);
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}
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return 0;
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err_detach_bridge:
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if (bridge->funcs->detach)
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bridge->funcs->detach(bridge);
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err_reset_bridge:
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bridge->dev = NULL;
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bridge->encoder = NULL;
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list_del(&bridge->chain_node);
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#ifdef CONFIG_OF
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DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n",
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bridge->of_node, encoder->name, ret);
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#else
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DRM_ERROR("failed to attach bridge to encoder %s: %d\n",
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encoder->name, ret);
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#endif
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return ret;
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}
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EXPORT_SYMBOL(drm_bridge_attach);
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void drm_bridge_detach(struct drm_bridge *bridge)
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{
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if (WARN_ON(!bridge))
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return;
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if (WARN_ON(!bridge->dev))
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return;
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if (bridge->funcs->atomic_reset)
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drm_atomic_private_obj_fini(&bridge->base);
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if (bridge->funcs->detach)
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bridge->funcs->detach(bridge);
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list_del(&bridge->chain_node);
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bridge->dev = NULL;
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}
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/**
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* DOC: bridge operations
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*
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* Bridge drivers expose operations through the &drm_bridge_funcs structure.
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* The DRM internals (atomic and CRTC helpers) use the helpers defined in
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* drm_bridge.c to call bridge operations. Those operations are divided in
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* three big categories to support different parts of the bridge usage.
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*
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* - The encoder-related operations support control of the bridges in the
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* chain, and are roughly counterparts to the &drm_encoder_helper_funcs
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* operations. They are used by the legacy CRTC and the atomic modeset
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* helpers to perform mode validation, fixup and setting, and enable and
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* disable the bridge automatically.
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*
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* The enable and disable operations are split in
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* &drm_bridge_funcs.pre_enable, &drm_bridge_funcs.enable,
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* &drm_bridge_funcs.disable and &drm_bridge_funcs.post_disable to provide
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* finer-grained control.
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*
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* Bridge drivers may implement the legacy version of those operations, or
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* the atomic version (prefixed with atomic\_), in which case they shall also
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* implement the atomic state bookkeeping operations
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* (&drm_bridge_funcs.atomic_duplicate_state,
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* &drm_bridge_funcs.atomic_destroy_state and &drm_bridge_funcs.reset).
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* Mixing atomic and non-atomic versions of the operations is not supported.
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*
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* - The bus format negotiation operations
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* &drm_bridge_funcs.atomic_get_output_bus_fmts and
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* &drm_bridge_funcs.atomic_get_input_bus_fmts allow bridge drivers to
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* negotiate the formats transmitted between bridges in the chain when
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* multiple formats are supported. Negotiation for formats is performed
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* transparently for display drivers by the atomic modeset helpers. Only
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* atomic versions of those operations exist, bridge drivers that need to
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* implement them shall thus also implement the atomic version of the
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* encoder-related operations. This feature is not supported by the legacy
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* CRTC helpers.
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*
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* - The connector-related operations support implementing a &drm_connector
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* based on a chain of bridges. DRM bridges traditionally create a
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* &drm_connector for bridges meant to be used at the end of the chain. This
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* puts additional burden on bridge drivers, especially for bridges that may
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* be used in the middle of a chain or at the end of it. Furthermore, it
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* requires all operations of the &drm_connector to be handled by a single
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* bridge, which doesn't always match the hardware architecture.
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*
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* To simplify bridge drivers and make the connector implementation more
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* flexible, a new model allows bridges to unconditionally skip creation of
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* &drm_connector and instead expose &drm_bridge_funcs operations to support
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* an externally-implemented &drm_connector. Those operations are
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* &drm_bridge_funcs.detect, &drm_bridge_funcs.get_modes,
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* &drm_bridge_funcs.get_edid, &drm_bridge_funcs.hpd_notify,
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* &drm_bridge_funcs.hpd_enable and &drm_bridge_funcs.hpd_disable. When
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* implemented, display drivers shall create a &drm_connector instance for
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* each chain of bridges, and implement those connector instances based on
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* the bridge connector operations.
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*
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* Bridge drivers shall implement the connector-related operations for all
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* the features that the bridge hardware support. For instance, if a bridge
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* supports reading EDID, the &drm_bridge_funcs.get_edid shall be
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* implemented. This however doesn't mean that the DDC lines are wired to the
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* bridge on a particular platform, as they could also be connected to an I2C
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* controller of the SoC. Support for the connector-related operations on the
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* running platform is reported through the &drm_bridge.ops flags. Bridge
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* drivers shall detect which operations they can support on the platform
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* (usually this information is provided by ACPI or DT), and set the
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* &drm_bridge.ops flags for all supported operations. A flag shall only be
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* set if the corresponding &drm_bridge_funcs operation is implemented, but
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* an implemented operation doesn't necessarily imply that the corresponding
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* flag will be set. Display drivers shall use the &drm_bridge.ops flags to
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* decide which bridge to delegate a connector operation to. This mechanism
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* allows providing a single static const &drm_bridge_funcs instance in
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* bridge drivers, improving security by storing function pointers in
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* read-only memory.
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*
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* In order to ease transition, bridge drivers may support both the old and
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* new models by making connector creation optional and implementing the
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* connected-related bridge operations. Connector creation is then controlled
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* by the flags argument to the drm_bridge_attach() function. Display drivers
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* that support the new model and create connectors themselves shall set the
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* %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, and bridge drivers shall then skip
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* connector creation. For intermediate bridges in the chain, the flag shall
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* be passed to the drm_bridge_attach() call for the downstream bridge.
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* Bridge drivers that implement the new model only shall return an error
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* from their &drm_bridge_funcs.attach handler when the
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* %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
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* should use the new model, and convert the bridge drivers they use if
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* needed, in order to gradually transition to the new model.
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*/
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/**
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* drm_bridge_chain_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 &drm_bridge_funcs.mode_fixup 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_chain_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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struct drm_encoder *encoder;
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if (!bridge)
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return true;
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encoder = bridge->encoder;
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list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
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if (!bridge->funcs->mode_fixup)
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continue;
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if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))
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return false;
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}
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return true;
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}
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EXPORT_SYMBOL(drm_bridge_chain_mode_fixup);
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|
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/**
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* drm_bridge_chain_mode_valid - validate the mode against all bridges in the
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* encoder chain.
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* @bridge: bridge control structure
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* @info: display info against which the mode shall be validated
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* @mode: desired mode to be validated
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*
|
|
* Calls &drm_bridge_funcs.mode_valid for all the bridges in the encoder
|
|
* chain, starting from the first bridge to the last. If at least one bridge
|
|
* does not accept the mode the function returns the error code.
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder.
|
|
*
|
|
* RETURNS:
|
|
* MODE_OK on success, drm_mode_status Enum error code on failure
|
|
*/
|
|
enum drm_mode_status
|
|
drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
|
|
const struct drm_display_info *info,
|
|
const struct drm_display_mode *mode)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return MODE_OK;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
enum drm_mode_status ret;
|
|
|
|
if (!bridge->funcs->mode_valid)
|
|
continue;
|
|
|
|
ret = bridge->funcs->mode_valid(bridge, info, mode);
|
|
if (ret != MODE_OK)
|
|
return ret;
|
|
}
|
|
|
|
return MODE_OK;
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
|
|
|
|
/**
|
|
* drm_bridge_chain_disable - disables all bridges in the encoder chain
|
|
* @bridge: bridge control structure
|
|
*
|
|
* Calls &drm_bridge_funcs.disable op for all the bridges in the encoder
|
|
* chain, starting from the last bridge to the first. These are called before
|
|
* calling the encoder's prepare op.
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_bridge_chain_disable(struct drm_bridge *bridge)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
struct drm_bridge *iter;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
|
|
if (iter->funcs->disable)
|
|
iter->funcs->disable(iter);
|
|
|
|
if (iter == bridge)
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_disable);
|
|
|
|
/**
|
|
* drm_bridge_chain_post_disable - cleans up after disabling all bridges in the
|
|
* encoder chain
|
|
* @bridge: bridge control structure
|
|
*
|
|
* Calls &drm_bridge_funcs.post_disable op for all the bridges in the
|
|
* encoder chain, starting from the first bridge to the last. These are called
|
|
* after completing the encoder's prepare op.
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_bridge_chain_post_disable(struct drm_bridge *bridge)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
if (bridge->funcs->post_disable)
|
|
bridge->funcs->post_disable(bridge);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_post_disable);
|
|
|
|
/**
|
|
* drm_bridge_chain_mode_set - set proposed mode for all bridges in the
|
|
* encoder chain
|
|
* @bridge: bridge control structure
|
|
* @mode: desired mode to be set for the encoder chain
|
|
* @adjusted_mode: updated mode that works for this encoder chain
|
|
*
|
|
* Calls &drm_bridge_funcs.mode_set op for all the bridges in the
|
|
* encoder chain, starting from the first bridge to the last.
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
|
|
const struct drm_display_mode *mode,
|
|
const struct drm_display_mode *adjusted_mode)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
if (bridge->funcs->mode_set)
|
|
bridge->funcs->mode_set(bridge, mode, adjusted_mode);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_mode_set);
|
|
|
|
/**
|
|
* drm_bridge_chain_pre_enable - prepares for enabling all bridges in the
|
|
* encoder chain
|
|
* @bridge: bridge control structure
|
|
*
|
|
* Calls &drm_bridge_funcs.pre_enable op for all the bridges in the encoder
|
|
* chain, starting from the last bridge to the first. These are called
|
|
* before calling the encoder's commit op.
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_bridge_chain_pre_enable(struct drm_bridge *bridge)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
struct drm_bridge *iter;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
|
|
if (iter->funcs->pre_enable)
|
|
iter->funcs->pre_enable(iter);
|
|
|
|
if (iter == bridge)
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_pre_enable);
|
|
|
|
/**
|
|
* drm_bridge_chain_enable - enables all bridges in the encoder chain
|
|
* @bridge: bridge control structure
|
|
*
|
|
* Calls &drm_bridge_funcs.enable op for all the bridges in the encoder
|
|
* chain, starting from the first bridge to the last. These are called
|
|
* after completing the encoder's commit op.
|
|
*
|
|
* Note that the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_bridge_chain_enable(struct drm_bridge *bridge)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
if (bridge->funcs->enable)
|
|
bridge->funcs->enable(bridge);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_bridge_chain_enable);
|
|
|
|
/**
|
|
* drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
|
|
* @bridge: bridge control structure
|
|
* @old_state: old atomic state
|
|
*
|
|
* Calls &drm_bridge_funcs.atomic_disable (falls back on
|
|
* &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
|
|
* starting from the last bridge to the first. These are called before calling
|
|
* &drm_encoder_helper_funcs.atomic_disable
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
|
|
struct drm_atomic_state *old_state)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
struct drm_bridge *iter;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
|
|
if (iter->funcs->atomic_disable) {
|
|
struct drm_bridge_state *old_bridge_state;
|
|
|
|
old_bridge_state =
|
|
drm_atomic_get_old_bridge_state(old_state,
|
|
iter);
|
|
if (WARN_ON(!old_bridge_state))
|
|
return;
|
|
|
|
iter->funcs->atomic_disable(iter, old_bridge_state);
|
|
} else if (iter->funcs->disable) {
|
|
iter->funcs->disable(iter);
|
|
}
|
|
|
|
if (iter == bridge)
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
|
|
|
|
/**
|
|
* drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
|
|
* in the encoder chain
|
|
* @bridge: bridge control structure
|
|
* @old_state: old atomic state
|
|
*
|
|
* Calls &drm_bridge_funcs.atomic_post_disable (falls back on
|
|
* &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain,
|
|
* starting from the first bridge to the last. These are called after completing
|
|
* &drm_encoder_helper_funcs.atomic_disable
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
|
|
struct drm_atomic_state *old_state)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
if (bridge->funcs->atomic_post_disable) {
|
|
struct drm_bridge_state *old_bridge_state;
|
|
|
|
old_bridge_state =
|
|
drm_atomic_get_old_bridge_state(old_state,
|
|
bridge);
|
|
if (WARN_ON(!old_bridge_state))
|
|
return;
|
|
|
|
bridge->funcs->atomic_post_disable(bridge,
|
|
old_bridge_state);
|
|
} else if (bridge->funcs->post_disable) {
|
|
bridge->funcs->post_disable(bridge);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
|
|
|
|
/**
|
|
* drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
|
|
* the encoder chain
|
|
* @bridge: bridge control structure
|
|
* @old_state: old atomic state
|
|
*
|
|
* Calls &drm_bridge_funcs.atomic_pre_enable (falls back on
|
|
* &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain,
|
|
* starting from the last bridge to the first. These are called before calling
|
|
* &drm_encoder_helper_funcs.atomic_enable
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
|
|
struct drm_atomic_state *old_state)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
struct drm_bridge *iter;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
|
|
if (iter->funcs->atomic_pre_enable) {
|
|
struct drm_bridge_state *old_bridge_state;
|
|
|
|
old_bridge_state =
|
|
drm_atomic_get_old_bridge_state(old_state,
|
|
iter);
|
|
if (WARN_ON(!old_bridge_state))
|
|
return;
|
|
|
|
iter->funcs->atomic_pre_enable(iter, old_bridge_state);
|
|
} else if (iter->funcs->pre_enable) {
|
|
iter->funcs->pre_enable(iter);
|
|
}
|
|
|
|
if (iter == bridge)
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
|
|
|
|
/**
|
|
* drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
|
|
* @bridge: bridge control structure
|
|
* @old_state: old atomic state
|
|
*
|
|
* Calls &drm_bridge_funcs.atomic_enable (falls back on
|
|
* &drm_bridge_funcs.enable) op for all the bridges in the encoder chain,
|
|
* starting from the first bridge to the last. These are called after completing
|
|
* &drm_encoder_helper_funcs.atomic_enable
|
|
*
|
|
* Note: the bridge passed should be the one closest to the encoder
|
|
*/
|
|
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
|
|
struct drm_atomic_state *old_state)
|
|
{
|
|
struct drm_encoder *encoder;
|
|
|
|
if (!bridge)
|
|
return;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
|
|
if (bridge->funcs->atomic_enable) {
|
|
struct drm_bridge_state *old_bridge_state;
|
|
|
|
old_bridge_state =
|
|
drm_atomic_get_old_bridge_state(old_state,
|
|
bridge);
|
|
if (WARN_ON(!old_bridge_state))
|
|
return;
|
|
|
|
bridge->funcs->atomic_enable(bridge, old_bridge_state);
|
|
} else if (bridge->funcs->enable) {
|
|
bridge->funcs->enable(bridge);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
|
|
|
|
static int drm_atomic_bridge_check(struct drm_bridge *bridge,
|
|
struct drm_crtc_state *crtc_state,
|
|
struct drm_connector_state *conn_state)
|
|
{
|
|
if (bridge->funcs->atomic_check) {
|
|
struct drm_bridge_state *bridge_state;
|
|
int ret;
|
|
|
|
bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
|
|
bridge);
|
|
if (WARN_ON(!bridge_state))
|
|
return -EINVAL;
|
|
|
|
ret = bridge->funcs->atomic_check(bridge, bridge_state,
|
|
crtc_state, conn_state);
|
|
if (ret)
|
|
return ret;
|
|
} else if (bridge->funcs->mode_fixup) {
|
|
if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,
|
|
&crtc_state->adjusted_mode))
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
|
|
struct drm_bridge *cur_bridge,
|
|
struct drm_crtc_state *crtc_state,
|
|
struct drm_connector_state *conn_state,
|
|
u32 out_bus_fmt)
|
|
{
|
|
struct drm_bridge_state *cur_state;
|
|
unsigned int num_in_bus_fmts, i;
|
|
struct drm_bridge *prev_bridge;
|
|
u32 *in_bus_fmts;
|
|
int ret;
|
|
|
|
prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
|
|
cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
|
|
cur_bridge);
|
|
|
|
/*
|
|
* If bus format negotiation is not supported by this bridge, let's
|
|
* pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and
|
|
* hope that it can handle this situation gracefully (by providing
|
|
* appropriate default values).
|
|
*/
|
|
if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {
|
|
if (cur_bridge != first_bridge) {
|
|
ret = select_bus_fmt_recursive(first_bridge,
|
|
prev_bridge, crtc_state,
|
|
conn_state,
|
|
MEDIA_BUS_FMT_FIXED);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Driver does not implement the atomic state hooks, but that's
|
|
* fine, as long as it does not access the bridge state.
|
|
*/
|
|
if (cur_state) {
|
|
cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;
|
|
cur_state->output_bus_cfg.format = out_bus_fmt;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* If the driver implements ->atomic_get_input_bus_fmts() it
|
|
* should also implement the atomic state hooks.
|
|
*/
|
|
if (WARN_ON(!cur_state))
|
|
return -EINVAL;
|
|
|
|
in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,
|
|
cur_state,
|
|
crtc_state,
|
|
conn_state,
|
|
out_bus_fmt,
|
|
&num_in_bus_fmts);
|
|
if (!num_in_bus_fmts)
|
|
return -ENOTSUPP;
|
|
else if (!in_bus_fmts)
|
|
return -ENOMEM;
|
|
|
|
if (first_bridge == cur_bridge) {
|
|
cur_state->input_bus_cfg.format = in_bus_fmts[0];
|
|
cur_state->output_bus_cfg.format = out_bus_fmt;
|
|
kfree(in_bus_fmts);
|
|
return 0;
|
|
}
|
|
|
|
for (i = 0; i < num_in_bus_fmts; i++) {
|
|
ret = select_bus_fmt_recursive(first_bridge, prev_bridge,
|
|
crtc_state, conn_state,
|
|
in_bus_fmts[i]);
|
|
if (ret != -ENOTSUPP)
|
|
break;
|
|
}
|
|
|
|
if (!ret) {
|
|
cur_state->input_bus_cfg.format = in_bus_fmts[i];
|
|
cur_state->output_bus_cfg.format = out_bus_fmt;
|
|
}
|
|
|
|
kfree(in_bus_fmts);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This function is called by &drm_atomic_bridge_chain_check() just before
|
|
* calling &drm_bridge_funcs.atomic_check() on all elements of the chain.
|
|
* It performs bus format negotiation between bridge elements. The negotiation
|
|
* happens in reverse order, starting from the last element in the chain up to
|
|
* @bridge.
|
|
*
|
|
* Negotiation starts by retrieving supported output bus formats on the last
|
|
* bridge element and testing them one by one. The test is recursive, meaning
|
|
* that for each tested output format, the whole chain will be walked backward,
|
|
* and each element will have to choose an input bus format that can be
|
|
* transcoded to the requested output format. When a bridge element does not
|
|
* support transcoding into a specific output format -ENOTSUPP is returned and
|
|
* the next bridge element will have to try a different format. If none of the
|
|
* combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
|
|
*
|
|
* This implementation is relying on
|
|
* &drm_bridge_funcs.atomic_get_output_bus_fmts() and
|
|
* &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported
|
|
* input/output formats.
|
|
*
|
|
* When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by
|
|
* the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts()
|
|
* tries a single format: &drm_connector.display_info.bus_formats[0] if
|
|
* available, MEDIA_BUS_FMT_FIXED otherwise.
|
|
*
|
|
* When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented,
|
|
* &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the
|
|
* bridge element that lacks this hook and asks the previous element in the
|
|
* chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what
|
|
* to do in that case (fail if they want to enforce bus format negotiation, or
|
|
* provide a reasonable default if they need to support pipelines where not
|
|
* all elements support bus format negotiation).
|
|
*/
|
|
static int
|
|
drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
|
|
struct drm_crtc_state *crtc_state,
|
|
struct drm_connector_state *conn_state)
|
|
{
|
|
struct drm_connector *conn = conn_state->connector;
|
|
struct drm_encoder *encoder = bridge->encoder;
|
|
struct drm_bridge_state *last_bridge_state;
|
|
unsigned int i, num_out_bus_fmts;
|
|
struct drm_bridge *last_bridge;
|
|
u32 *out_bus_fmts;
|
|
int ret = 0;
|
|
|
|
last_bridge = list_last_entry(&encoder->bridge_chain,
|
|
struct drm_bridge, chain_node);
|
|
last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
|
|
last_bridge);
|
|
|
|
if (last_bridge->funcs->atomic_get_output_bus_fmts) {
|
|
const struct drm_bridge_funcs *funcs = last_bridge->funcs;
|
|
|
|
/*
|
|
* If the driver implements ->atomic_get_output_bus_fmts() it
|
|
* should also implement the atomic state hooks.
|
|
*/
|
|
if (WARN_ON(!last_bridge_state))
|
|
return -EINVAL;
|
|
|
|
out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,
|
|
last_bridge_state,
|
|
crtc_state,
|
|
conn_state,
|
|
&num_out_bus_fmts);
|
|
if (!num_out_bus_fmts)
|
|
return -ENOTSUPP;
|
|
else if (!out_bus_fmts)
|
|
return -ENOMEM;
|
|
} else {
|
|
num_out_bus_fmts = 1;
|
|
out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
|
|
if (!out_bus_fmts)
|
|
return -ENOMEM;
|
|
|
|
if (conn->display_info.num_bus_formats &&
|
|
conn->display_info.bus_formats)
|
|
out_bus_fmts[0] = conn->display_info.bus_formats[0];
|
|
else
|
|
out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
|
|
}
|
|
|
|
for (i = 0; i < num_out_bus_fmts; i++) {
|
|
ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state,
|
|
conn_state, out_bus_fmts[i]);
|
|
if (ret != -ENOTSUPP)
|
|
break;
|
|
}
|
|
|
|
kfree(out_bus_fmts);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
|
|
struct drm_connector *conn,
|
|
struct drm_atomic_state *state)
|
|
{
|
|
struct drm_bridge_state *bridge_state, *next_bridge_state;
|
|
struct drm_bridge *next_bridge;
|
|
u32 output_flags = 0;
|
|
|
|
bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
|
|
|
|
/* No bridge state attached to this bridge => nothing to propagate. */
|
|
if (!bridge_state)
|
|
return;
|
|
|
|
next_bridge = drm_bridge_get_next_bridge(bridge);
|
|
|
|
/*
|
|
* Let's try to apply the most common case here, that is, propagate
|
|
* display_info flags for the last bridge, and propagate the input
|
|
* flags of the next bridge element to the output end of the current
|
|
* bridge when the bridge is not the last one.
|
|
* There are exceptions to this rule, like when signal inversion is
|
|
* happening at the board level, but that's something drivers can deal
|
|
* with from their &drm_bridge_funcs.atomic_check() implementation by
|
|
* simply overriding the flags value we've set here.
|
|
*/
|
|
if (!next_bridge) {
|
|
output_flags = conn->display_info.bus_flags;
|
|
} else {
|
|
next_bridge_state = drm_atomic_get_new_bridge_state(state,
|
|
next_bridge);
|
|
/*
|
|
* No bridge state attached to the next bridge, just leave the
|
|
* flags to 0.
|
|
*/
|
|
if (next_bridge_state)
|
|
output_flags = next_bridge_state->input_bus_cfg.flags;
|
|
}
|
|
|
|
bridge_state->output_bus_cfg.flags = output_flags;
|
|
|
|
/*
|
|
* Propagate the output flags to the input end of the bridge. Again, it's
|
|
* not necessarily what all bridges want, but that's what most of them
|
|
* do, and by doing that by default we avoid forcing drivers to
|
|
* duplicate the "dummy propagation" logic.
|
|
*/
|
|
bridge_state->input_bus_cfg.flags = output_flags;
|
|
}
|
|
|
|
/**
|
|
* drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
|
|
* @bridge: bridge control structure
|
|
* @crtc_state: new CRTC state
|
|
* @conn_state: new connector state
|
|
*
|
|
* First trigger a bus format negotiation before calling
|
|
* &drm_bridge_funcs.atomic_check() (falls back on
|
|
* &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
|
|
* starting from the last bridge to the first. These are called before calling
|
|
* &drm_encoder_helper_funcs.atomic_check()
|
|
*
|
|
* RETURNS:
|
|
* 0 on success, a negative error code on failure
|
|
*/
|
|
int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
|
|
struct drm_crtc_state *crtc_state,
|
|
struct drm_connector_state *conn_state)
|
|
{
|
|
struct drm_connector *conn = conn_state->connector;
|
|
struct drm_encoder *encoder;
|
|
struct drm_bridge *iter;
|
|
int ret;
|
|
|
|
if (!bridge)
|
|
return 0;
|
|
|
|
ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
|
|
conn_state);
|
|
if (ret)
|
|
return ret;
|
|
|
|
encoder = bridge->encoder;
|
|
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
|
|
int ret;
|
|
|
|
/*
|
|
* Bus flags are propagated by default. If a bridge needs to
|
|
* tweak the input bus flags for any reason, it should happen
|
|
* in its &drm_bridge_funcs.atomic_check() implementation such
|
|
* that preceding bridges in the chain can propagate the new
|
|
* bus flags.
|
|
*/
|
|
drm_atomic_bridge_propagate_bus_flags(iter, conn,
|
|
crtc_state->state);
|
|
|
|
ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (iter == bridge)
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
|
|
|
|
/**
|
|
* drm_bridge_detect - check if anything is attached to the bridge output
|
|
* @bridge: bridge control structure
|
|
*
|
|
* If the bridge supports output detection, as reported by the
|
|
* DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the
|
|
* bridge and return the connection status. Otherwise return
|
|
* connector_status_unknown.
|
|
*
|
|
* RETURNS:
|
|
* The detection status on success, or connector_status_unknown if the bridge
|
|
* doesn't support output detection.
|
|
*/
|
|
enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge)
|
|
{
|
|
if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))
|
|
return connector_status_unknown;
|
|
|
|
return bridge->funcs->detect(bridge);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_detect);
|
|
|
|
/**
|
|
* drm_bridge_get_modes - fill all modes currently valid for the sink into the
|
|
* @connector
|
|
* @bridge: bridge control structure
|
|
* @connector: the connector to fill with modes
|
|
*
|
|
* If the bridge supports output modes retrieval, as reported by the
|
|
* DRM_BRIDGE_OP_MODES bridge ops flag, call &drm_bridge_funcs.get_modes to
|
|
* fill the connector with all valid modes and return the number of modes
|
|
* added. Otherwise return 0.
|
|
*
|
|
* RETURNS:
|
|
* The number of modes added to the connector.
|
|
*/
|
|
int drm_bridge_get_modes(struct drm_bridge *bridge,
|
|
struct drm_connector *connector)
|
|
{
|
|
if (!(bridge->ops & DRM_BRIDGE_OP_MODES))
|
|
return 0;
|
|
|
|
return bridge->funcs->get_modes(bridge, connector);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
|
|
|
|
/**
|
|
* drm_bridge_get_edid - get the EDID data of the connected display
|
|
* @bridge: bridge control structure
|
|
* @connector: the connector to read EDID for
|
|
*
|
|
* If the bridge supports output EDID retrieval, as reported by the
|
|
* DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
|
|
* get the EDID and return it. Otherwise return NULL.
|
|
*
|
|
* RETURNS:
|
|
* The retrieved EDID on success, or NULL otherwise.
|
|
*/
|
|
struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
|
|
struct drm_connector *connector)
|
|
{
|
|
if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
|
|
return NULL;
|
|
|
|
return bridge->funcs->get_edid(bridge, connector);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_get_edid);
|
|
|
|
/**
|
|
* drm_bridge_hpd_enable - enable hot plug detection for the bridge
|
|
* @bridge: bridge control structure
|
|
* @cb: hot-plug detection callback
|
|
* @data: data to be passed to the hot-plug detection callback
|
|
*
|
|
* Call &drm_bridge_funcs.hpd_enable if implemented and register the given @cb
|
|
* and @data as hot plug notification callback. From now on the @cb will be
|
|
* called with @data when an output status change is detected by the bridge,
|
|
* until hot plug notification gets disabled with drm_bridge_hpd_disable().
|
|
*
|
|
* Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
|
|
* bridge->ops. This function shall not be called when the flag is not set.
|
|
*
|
|
* Only one hot plug detection callback can be registered at a time, it is an
|
|
* error to call this function when hot plug detection is already enabled for
|
|
* the bridge.
|
|
*/
|
|
void drm_bridge_hpd_enable(struct drm_bridge *bridge,
|
|
void (*cb)(void *data,
|
|
enum drm_connector_status status),
|
|
void *data)
|
|
{
|
|
if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
|
|
return;
|
|
|
|
mutex_lock(&bridge->hpd_mutex);
|
|
|
|
if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))
|
|
goto unlock;
|
|
|
|
bridge->hpd_cb = cb;
|
|
bridge->hpd_data = data;
|
|
|
|
if (bridge->funcs->hpd_enable)
|
|
bridge->funcs->hpd_enable(bridge);
|
|
|
|
unlock:
|
|
mutex_unlock(&bridge->hpd_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_hpd_enable);
|
|
|
|
/**
|
|
* drm_bridge_hpd_disable - disable hot plug detection for the bridge
|
|
* @bridge: bridge control structure
|
|
*
|
|
* Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot
|
|
* plug detection callback previously registered with drm_bridge_hpd_enable().
|
|
* Once this function returns the callback will not be called by the bridge
|
|
* when an output status change occurs.
|
|
*
|
|
* Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
|
|
* bridge->ops. This function shall not be called when the flag is not set.
|
|
*/
|
|
void drm_bridge_hpd_disable(struct drm_bridge *bridge)
|
|
{
|
|
if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
|
|
return;
|
|
|
|
mutex_lock(&bridge->hpd_mutex);
|
|
if (bridge->funcs->hpd_disable)
|
|
bridge->funcs->hpd_disable(bridge);
|
|
|
|
bridge->hpd_cb = NULL;
|
|
bridge->hpd_data = NULL;
|
|
mutex_unlock(&bridge->hpd_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_hpd_disable);
|
|
|
|
/**
|
|
* drm_bridge_hpd_notify - notify hot plug detection events
|
|
* @bridge: bridge control structure
|
|
* @status: output connection status
|
|
*
|
|
* Bridge drivers shall call this function to report hot plug events when they
|
|
* detect a change in the output status, when hot plug detection has been
|
|
* enabled by drm_bridge_hpd_enable().
|
|
*
|
|
* This function shall be called in a context that can sleep.
|
|
*/
|
|
void drm_bridge_hpd_notify(struct drm_bridge *bridge,
|
|
enum drm_connector_status status)
|
|
{
|
|
mutex_lock(&bridge->hpd_mutex);
|
|
if (bridge->hpd_cb)
|
|
bridge->hpd_cb(bridge->hpd_data, status);
|
|
mutex_unlock(&bridge->hpd_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify);
|
|
|
|
#ifdef CONFIG_OF
|
|
/**
|
|
* of_drm_find_bridge - find the bridge corresponding to the device node in
|
|
* the global bridge list
|
|
*
|
|
* @np: device node
|
|
*
|
|
* RETURNS:
|
|
* drm_bridge control struct on success, NULL on failure
|
|
*/
|
|
struct drm_bridge *of_drm_find_bridge(struct device_node *np)
|
|
{
|
|
struct drm_bridge *bridge;
|
|
|
|
mutex_lock(&bridge_lock);
|
|
|
|
list_for_each_entry(bridge, &bridge_list, list) {
|
|
if (bridge->of_node == np) {
|
|
mutex_unlock(&bridge_lock);
|
|
return bridge;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&bridge_lock);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(of_drm_find_bridge);
|
|
#endif
|
|
|
|
MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
|
|
MODULE_DESCRIPTION("DRM bridge infrastructure");
|
|
MODULE_LICENSE("GPL and additional rights");
|