Re: [PATCH V8 03/14] drm/bridge: make bridge registration independent of drm flow

From: Ajay kumar <ajaynumb@gmail.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: "dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-samsung-soc@vger.kernel.org"
	<linux-samsung-soc@vger.kernel.org>,
	Ajay Kumar <ajaykumar.rs@samsung.com>,
	InKi Dae <inki.dae@samsung.com>,
	Kukjin Kim <kgene.kim@samsung.com>,
	Sean Paul <seanpaul@google.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	Pannaga Bhushan Reddy Patel <bhushan.r@samsung.com>,
	Prashanth G <prashanth.g@samsung.com>
Subject: Re: [PATCH V8 03/14] drm/bridge: make bridge registration independent of drm flow
Date: Tue, 2 Dec 2014 11:31:35 +0530	[thread overview]
Message-ID: <CAEC9eQMhTv1hakk_y0a5AWhyvzPZgmicmRserfNubX99kzL19g@mail.gmail.com> (raw)
In-Reply-To: <1416045309-13359-4-git-send-email-ajaykumar.rs@samsung.com>

On Sat, Nov 15, 2014 at 3:24 PM, Ajay Kumar <ajaykumar.rs@samsung.com> wrote:
> Currently, third party bridge drivers(ptn3460) are dependent
> on the corresponding encoder driver init, since bridge driver
> needs a drm_device pointer to finish drm initializations.
> The encoder driver passes the drm_device pointer to the
> bridge driver. Because of this dependency, third party drivers
> like ptn3460 doesn't adhere to the driver model.
>
> In this patch, we reframe the bridge registration framework
> so that bridge initialization is split into 2 steps, and
> bridge registration happens independent of drm flow:
> --Step 1: gather all the bridge settings independent of drm and
>           add the bridge onto a global list of bridges.
> --Step 2: when the encoder driver is probed, call drm_bridge_attach
>           for the corresponding bridge so that the bridge receives
>           drm_device pointer and continues with connector and other
>           drm initializations.
>
> The old set of bridge helpers are removed, and a set of new helpers
> are added to accomplish the 2 step initialization.
>
> The bridge devices register themselves onto global list of bridges
> when they get probed by calling "drm_bridge_add".
>
> The parent encoder driver waits till the bridge is available
> in the lookup table(by calling "of_drm_find_bridge") and then
> continues with its initialization.
>
> The encoder driver should also call "drm_bridge_attach" to pass
> on the drm_device to the bridge object.
>
> drm_bridge_attach inturn calls "bridge->funcs->attach" so that
> bridge can continue with drm related initializations.
>
> Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
> ---
>  drivers/gpu/drm/Makefile               |    2 +-
>  drivers/gpu/drm/bridge/ptn3460.c       |   27 +++++-----
>  drivers/gpu/drm/drm_bridge.c           |   91 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc.c             |   65 -----------------------
>  drivers/gpu/drm/msm/hdmi/hdmi.c        |    7 +--
>  drivers/gpu/drm/msm/hdmi/hdmi.h        |    1 +
>  drivers/gpu/drm/msm/hdmi/hdmi_bridge.c |    7 ++-
>  drivers/gpu/drm/sti/sti_hda.c          |   10 +---
>  drivers/gpu/drm/sti/sti_hdmi.c         |   10 +---
>  include/drm/bridge/ptn3460.h           |    8 +++
>  include/drm/drm_crtc.h                 |   26 ++++-----
>  11 files changed, 136 insertions(+), 118 deletions(-)
>  create mode 100644 drivers/gpu/drm/drm_bridge.c
>
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 9292a76..00f97a5 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -14,7 +14,7 @@ drm-y       :=        drm_auth.o drm_bufs.o drm_cache.o \
>                 drm_info.o drm_debugfs.o drm_encoder_slave.o \
>                 drm_trace_points.o drm_global.o drm_prime.o \
>                 drm_rect.o drm_vma_manager.o drm_flip_work.o \
> -               drm_modeset_lock.o
> +               drm_modeset_lock.o drm_bridge.o
>
>  drm-$(CONFIG_COMPAT) += drm_ioc32.o
>  drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
> diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
> index a2ddc8d..4a818c1 100644
> --- a/drivers/gpu/drm/bridge/ptn3460.c
> +++ b/drivers/gpu/drm/bridge/ptn3460.c
> @@ -176,24 +176,11 @@ static void ptn3460_post_disable(struct drm_bridge *bridge)
>  {
>  }
>
> -static void ptn3460_bridge_destroy(struct drm_bridge *bridge)
> -{
> -       struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
> -
> -       drm_bridge_cleanup(bridge);
> -       if (gpio_is_valid(ptn_bridge->gpio_pd_n))
> -               gpio_free(ptn_bridge->gpio_pd_n);
> -       if (gpio_is_valid(ptn_bridge->gpio_rst_n))
> -               gpio_free(ptn_bridge->gpio_rst_n);
> -       /* Nothing else to free, we've got devm allocated memory */
> -}
> -
>  static struct drm_bridge_funcs ptn3460_bridge_funcs = {
>         .pre_enable = ptn3460_pre_enable,
>         .enable = ptn3460_enable,
>         .disable = ptn3460_disable,
>         .post_disable = ptn3460_post_disable,
> -       .destroy = ptn3460_bridge_destroy,
>  };
>
>  static int ptn3460_get_modes(struct drm_connector *connector)
> @@ -314,7 +301,7 @@ int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>         }
>
>         ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
> -       ret = drm_bridge_init(dev, &ptn_bridge->bridge);
> +       ret = drm_bridge_attach(dev, &ptn_bridge->bridge);
>         if (ret) {
>                 DRM_ERROR("Failed to initialize bridge with drm\n");
>                 goto err;
> @@ -343,3 +330,15 @@ err:
>         return ret;
>  }
>  EXPORT_SYMBOL(ptn3460_init);
> +
> +void ptn3460_destroy(struct drm_bridge *bridge)
> +{
> +       struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
> +
> +       if (gpio_is_valid(ptn_bridge->gpio_pd_n))
> +               gpio_free(ptn_bridge->gpio_pd_n);
> +       if (gpio_is_valid(ptn_bridge->gpio_rst_n))
> +               gpio_free(ptn_bridge->gpio_rst_n);
> +       /* Nothing else to free, we've got devm allocated memory */
> +}
> +EXPORT_SYMBOL(ptn3460_destroy);
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> new file mode 100644
> index 0000000..d1187e5
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -0,0 +1,91 @@
> +/*
> + * Copyright (c) 2014 Samsung Electronics Co., Ltd
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sub license,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the
> + * next paragraph) shall be included in all copies or substantial portions
> + * of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/module.h>
> +
> +#include <drm/drm_crtc.h>
> +
> +#include "drm/drmP.h"
> +
> +static DEFINE_MUTEX(bridge_lock);
> +static LIST_HEAD(bridge_list);
> +
> +int drm_bridge_add(struct drm_bridge *bridge)
> +{
> +       mutex_lock(&bridge_lock);
> +       list_add_tail(&bridge->list, &bridge_list);
> +       mutex_unlock(&bridge_lock);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(drm_bridge_add);
> +
> +void drm_bridge_remove(struct drm_bridge *bridge)
> +{
> +       mutex_lock(&bridge_lock);
> +       list_del_init(&bridge->list);
> +       mutex_unlock(&bridge_lock);
> +}
> +EXPORT_SYMBOL(drm_bridge_remove);
> +
> +extern int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge)
> +{
> +       if (!dev || !bridge)
> +               return -EINVAL;
> +
> +       if (bridge->dev)
> +               return -EBUSY;
> +
> +       bridge->dev = dev;
> +
> +       if (bridge->funcs->attach)
> +               return bridge->funcs->attach(bridge);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(drm_bridge_attach);
> +
> +#ifdef CONFIG_OF
> +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");
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 408c053..39d6100 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1008,56 +1008,6 @@ void drm_connector_unplug_all(struct drm_device *dev)
>  EXPORT_SYMBOL(drm_connector_unplug_all);
>
>  /**
> - * drm_bridge_init - initialize a drm transcoder/bridge
> - * @dev: drm device
> - * @bridge: transcoder/bridge to set up
> - *
> - * Initialises a preallocated bridge. Bridges should be
> - * subclassed as part of driver connector objects.
> - *
> - * Returns:
> - * Zero on success, error code on failure.
> - */
> -int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge)
> -{
> -       int ret;
> -
> -       drm_modeset_lock_all(dev);
> -
> -       ret = drm_mode_object_get(dev, &bridge->base, DRM_MODE_OBJECT_BRIDGE);
> -       if (ret)
> -               goto out;
> -
> -       bridge->dev = dev;
> -
> -       list_add_tail(&bridge->head, &dev->mode_config.bridge_list);
> -       dev->mode_config.num_bridge++;
> -
> - out:
> -       drm_modeset_unlock_all(dev);
> -       return ret;
> -}
> -EXPORT_SYMBOL(drm_bridge_init);
> -
> -/**
> - * drm_bridge_cleanup - cleans up an initialised bridge
> - * @bridge: bridge to cleanup
> - *
> - * Cleans up the bridge but doesn't free the object.
> - */
> -void drm_bridge_cleanup(struct drm_bridge *bridge)
> -{
> -       struct drm_device *dev = bridge->dev;
> -
> -       drm_modeset_lock_all(dev);
> -       drm_mode_object_put(dev, &bridge->base);
> -       list_del(&bridge->head);
> -       dev->mode_config.num_bridge--;
> -       drm_modeset_unlock_all(dev);
> -}
> -EXPORT_SYMBOL(drm_bridge_cleanup);
> -
> -/**
>   * drm_encoder_init - Init a preallocated encoder
>   * @dev: drm device
>   * @encoder: the encoder to init
> @@ -1539,7 +1489,6 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         total_objects += dev->mode_config.num_crtc;
>         total_objects += dev->mode_config.num_connector;
>         total_objects += dev->mode_config.num_encoder;
> -       total_objects += dev->mode_config.num_bridge;
>
>         group->id_list = kzalloc(total_objects * sizeof(uint32_t), GFP_KERNEL);
>         if (!group->id_list)
> @@ -1548,7 +1497,6 @@ static int drm_mode_group_init(struct drm_device *dev, struct drm_mode_group *gr
>         group->num_crtcs = 0;
>         group->num_connectors = 0;
>         group->num_encoders = 0;
> -       group->num_bridges = 0;
>         return 0;
>  }
>
> @@ -1568,7 +1516,6 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>         struct drm_crtc *crtc;
>         struct drm_encoder *encoder;
>         struct drm_connector *connector;
> -       struct drm_bridge *bridge;
>         int ret;
>
>         if ((ret = drm_mode_group_init(dev, group)))
> @@ -1585,11 +1532,6 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
>                 group->id_list[group->num_crtcs + group->num_encoders +
>                                group->num_connectors++] = connector->base.id;
>
> -       list_for_each_entry(bridge, &dev->mode_config.bridge_list, head)
> -               group->id_list[group->num_crtcs + group->num_encoders +
> -                              group->num_connectors + group->num_bridges++] =
> -                                       bridge->base.id;
> -
>         return 0;
>  }
>  EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
> @@ -5088,7 +5030,6 @@ void drm_mode_config_init(struct drm_device *dev)
>         INIT_LIST_HEAD(&dev->mode_config.fb_list);
>         INIT_LIST_HEAD(&dev->mode_config.crtc_list);
>         INIT_LIST_HEAD(&dev->mode_config.connector_list);
> -       INIT_LIST_HEAD(&dev->mode_config.bridge_list);
>         INIT_LIST_HEAD(&dev->mode_config.encoder_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_list);
>         INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
> @@ -5128,7 +5069,6 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>         struct drm_connector *connector, *ot;
>         struct drm_crtc *crtc, *ct;
>         struct drm_encoder *encoder, *enct;
> -       struct drm_bridge *bridge, *brt;
>         struct drm_framebuffer *fb, *fbt;
>         struct drm_property *property, *pt;
>         struct drm_property_blob *blob, *bt;
> @@ -5139,11 +5079,6 @@ void drm_mode_config_cleanup(struct drm_device *dev)
>                 encoder->funcs->destroy(encoder);
>         }
>
> -       list_for_each_entry_safe(bridge, brt,
> -                                &dev->mode_config.bridge_list, head) {
> -               bridge->funcs->destroy(bridge);
> -       }
> -
>         list_for_each_entry_safe(connector, ot,
>                                  &dev->mode_config.connector_list, head) {
>                 connector->funcs->destroy(connector);
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> index 9d00dcb..e4f249b 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> @@ -65,6 +65,9 @@ void hdmi_destroy(struct kref *kref)
>         if (hdmi->i2c)
>                 hdmi_i2c_destroy(hdmi->i2c);
>
> +       if (hdmi->bridge)
> +               hdmi_bridge_destroy(hdmi->bridge);
> +
>         platform_set_drvdata(hdmi->pdev, NULL);
>  }
>
> @@ -234,9 +237,7 @@ struct hdmi *hdmi_init(struct drm_device *dev, struct drm_encoder *encoder)
>
>  fail:
>         if (hdmi) {
> -               /* bridge/connector are normally destroyed by drm: */
> -               if (hdmi->bridge)
> -                       hdmi->bridge->funcs->destroy(hdmi->bridge);
> +               /* bridge is normally destroyed by drm: */
>                 if (hdmi->connector)
>                         hdmi->connector->funcs->destroy(hdmi->connector);
>                 hdmi_destroy(&hdmi->refcount);
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.h b/drivers/gpu/drm/msm/hdmi/hdmi.h
> index b981995..d2cf7f4 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.h
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.h
> @@ -163,6 +163,7 @@ void hdmi_audio_set_sample_rate(struct hdmi *hdmi, int rate);
>   */
>
>  struct drm_bridge *hdmi_bridge_init(struct hdmi *hdmi);
> +void hdmi_bridge_destroy(struct drm_bridge *bridge);
>
>  /*
>   * hdmi connector:
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
> index 0309539..26657a0 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
> @@ -23,11 +23,11 @@ struct hdmi_bridge {
>  };
>  #define to_hdmi_bridge(x) container_of(x, struct hdmi_bridge, base)
>
> -static void hdmi_bridge_destroy(struct drm_bridge *bridge)
> +void hdmi_bridge_destroy(struct drm_bridge *bridge)
>  {
>         struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
> +
>         hdmi_unreference(hdmi_bridge->hdmi);
> -       drm_bridge_cleanup(bridge);
>         kfree(hdmi_bridge);
>  }
>
> @@ -201,7 +201,6 @@ static const struct drm_bridge_funcs hdmi_bridge_funcs = {
>                 .disable = hdmi_bridge_disable,
>                 .post_disable = hdmi_bridge_post_disable,
>                 .mode_set = hdmi_bridge_mode_set,
> -               .destroy = hdmi_bridge_destroy,
>  };
>
>
> @@ -223,7 +222,7 @@ struct drm_bridge *hdmi_bridge_init(struct hdmi *hdmi)
>         bridge = &hdmi_bridge->base;
>         bridge->funcs = &hdmi_bridge_funcs;
>
> -       drm_bridge_init(hdmi->dev, bridge);
> +       drm_bridge_attach(hdmi->dev, bridge);
>
>         return bridge;
>
> diff --git a/drivers/gpu/drm/sti/sti_hda.c b/drivers/gpu/drm/sti/sti_hda.c
> index 6cf145d..a9bbb08 100644
> --- a/drivers/gpu/drm/sti/sti_hda.c
> +++ b/drivers/gpu/drm/sti/sti_hda.c
> @@ -508,19 +508,12 @@ static void sti_hda_bridge_nope(struct drm_bridge *bridge)
>         /* do nothing */
>  }
>
> -static void sti_hda_brigde_destroy(struct drm_bridge *bridge)
> -{
> -       drm_bridge_cleanup(bridge);
> -       kfree(bridge);
> -}
> -
>  static const struct drm_bridge_funcs sti_hda_bridge_funcs = {
>         .pre_enable = sti_hda_pre_enable,
>         .enable = sti_hda_bridge_nope,
>         .disable = sti_hda_disable,
>         .post_disable = sti_hda_bridge_nope,
>         .mode_set = sti_hda_set_mode,
> -       .destroy = sti_hda_brigde_destroy,
>  };
>
>  static int sti_hda_connector_get_modes(struct drm_connector *connector)
> @@ -665,7 +658,7 @@ static int sti_hda_bind(struct device *dev, struct device *master, void *data)
>
>         bridge->driver_private = hda;
>         bridge->funcs = &sti_hda_bridge_funcs;
> -       drm_bridge_init(drm_dev, bridge);
> +       drm_bridge_attach(drm_dev, bridge);
>
>         encoder->bridge = bridge;
>         connector->encoder = encoder;
> @@ -694,7 +687,6 @@ static int sti_hda_bind(struct device *dev, struct device *master, void *data)
>  err_sysfs:
>         drm_connector_unregister(drm_connector);
>  err_connector:
> -       drm_bridge_cleanup(bridge);
>         drm_connector_cleanup(drm_connector);
>         return -EINVAL;
>  }
> diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
> index 285f723..bf4cdb8 100644
> --- a/drivers/gpu/drm/sti/sti_hdmi.c
> +++ b/drivers/gpu/drm/sti/sti_hdmi.c
> @@ -463,19 +463,12 @@ static void sti_hdmi_bridge_nope(struct drm_bridge *bridge)
>         /* do nothing */
>  }
>
> -static void sti_hdmi_brigde_destroy(struct drm_bridge *bridge)
> -{
> -       drm_bridge_cleanup(bridge);
> -       kfree(bridge);
> -}
> -
>  static const struct drm_bridge_funcs sti_hdmi_bridge_funcs = {
>         .pre_enable = sti_hdmi_pre_enable,
>         .enable = sti_hdmi_bridge_nope,
>         .disable = sti_hdmi_disable,
>         .post_disable = sti_hdmi_bridge_nope,
>         .mode_set = sti_hdmi_set_mode,
> -       .destroy = sti_hdmi_brigde_destroy,
>  };
>
>  static int sti_hdmi_connector_get_modes(struct drm_connector *connector)
> @@ -629,7 +622,7 @@ static int sti_hdmi_bind(struct device *dev, struct device *master, void *data)
>
>         bridge->driver_private = hdmi;
>         bridge->funcs = &sti_hdmi_bridge_funcs;
> -       drm_bridge_init(drm_dev, bridge);
> +       drm_bridge_attach(drm_dev, bridge);
>
>         encoder->bridge = bridge;
>         connector->encoder = encoder;
> @@ -661,7 +654,6 @@ static int sti_hdmi_bind(struct device *dev, struct device *master, void *data)
>  err_sysfs:
>         drm_connector_unregister(drm_connector);
>  err_connector:
> -       drm_bridge_cleanup(bridge);
>         drm_connector_cleanup(drm_connector);
>         return -EINVAL;
>  }
> diff --git a/include/drm/bridge/ptn3460.h b/include/drm/bridge/ptn3460.h
> index ff62344..b11f8e1 100644
> --- a/include/drm/bridge/ptn3460.h
> +++ b/include/drm/bridge/ptn3460.h
> @@ -15,6 +15,7 @@
>  #define _DRM_BRIDGE_PTN3460_H_
>
>  struct drm_device;
> +struct drm_bridge;
>  struct drm_encoder;
>  struct i2c_client;
>  struct device_node;
> @@ -23,6 +24,9 @@ struct device_node;
>
>  int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
>                 struct i2c_client *client, struct device_node *node);
> +
> +void ptn3460_destroy(struct drm_bridge *bridge);
> +
>  #else
>
>  static inline int ptn3460_init(struct drm_device *dev,
> @@ -32,6 +36,10 @@ static inline int ptn3460_init(struct drm_device *dev,
>         return 0;
>  }
>
> +static inline void ptn3460_destroy(struct drm_bridge *bridge)
> +{
> +}
> +
>  #endif
>
>  #endif
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 5a3bce17..da2beaf 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -633,15 +633,16 @@ struct drm_plane {
>
>  /**
>   * drm_bridge_funcs - drm_bridge control functions
> + * @attach: Called during drm_bridge_attach
>   * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
>   * @disable: Called right before encoder prepare, disables the bridge
>   * @post_disable: Called right after encoder prepare, for lockstepped disable
>   * @mode_set: Set this mode to the bridge
>   * @pre_enable: Called right before encoder commit, for lockstepped commit
>   * @enable: Called right after encoder commit, enables the bridge
> - * @destroy: make object go away
>   */
>  struct drm_bridge_funcs {
> +       int (*attach)(struct drm_bridge *bridge);
>         bool (*mode_fixup)(struct drm_bridge *bridge,
>                            const struct drm_display_mode *mode,
>                            struct drm_display_mode *adjusted_mode);
> @@ -652,22 +653,24 @@ struct drm_bridge_funcs {
>                          struct drm_display_mode *adjusted_mode);
>         void (*pre_enable)(struct drm_bridge *bridge);
>         void (*enable)(struct drm_bridge *bridge);
> -       void (*destroy)(struct drm_bridge *bridge);
>  };
>
>  /**
>   * drm_bridge - central DRM bridge control structure
>   * @dev: DRM device this bridge belongs to
> - * @head: list management
> + * @of_node: device node pointer to the bridge
> + * @list: to keep track of all added bridges
>   * @base: base mode object
>   * @funcs: control functions
>   * @driver_private: pointer to the bridge driver's internal context
>   */
>  struct drm_bridge {
>         struct drm_device *dev;
> -       struct list_head head;
> -
> -       struct drm_mode_object base;
> +       struct drm_encoder *encoder;
> +#ifdef CONFIG_OF
> +       struct device_node *of_node;
> +#endif
> +       struct list_head list;
>
>         const struct drm_bridge_funcs *funcs;
>         void *driver_private;
> @@ -733,7 +736,6 @@ struct drm_mode_group {
>         uint32_t num_crtcs;
>         uint32_t num_encoders;
>         uint32_t num_connectors;
> -       uint32_t num_bridges;
>
>         /* list of object IDs for this group */
>         uint32_t *id_list;
> @@ -748,8 +750,6 @@ struct drm_mode_group {
>   * @fb_list: list of framebuffers available
>   * @num_connector: number of connectors on this device
>   * @connector_list: list of connector objects
> - * @num_bridge: number of bridges on this device
> - * @bridge_list: list of bridge objects
>   * @num_encoder: number of encoders on this device
>   * @encoder_list: list of encoder objects
>   * @num_crtc: number of CRTCs on this device
> @@ -789,8 +789,6 @@ struct drm_mode_config {
>
>         int num_connector;
>         struct list_head connector_list;
> -       int num_bridge;
> -       struct list_head bridge_list;
>         int num_encoder;
>         struct list_head encoder_list;
>
> @@ -912,8 +910,10 @@ extern unsigned int drm_connector_index(struct drm_connector *connector);
>  /* helper to unplug all connectors from sysfs for device */
>  extern void drm_connector_unplug_all(struct drm_device *dev);
>
> -extern int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge);
> -extern void drm_bridge_cleanup(struct drm_bridge *bridge);
> +extern int drm_bridge_add(struct drm_bridge *bridge);
> +extern void drm_bridge_remove(struct drm_bridge *bridge);
> +extern struct drm_bridge *of_drm_find_bridge(struct device_node *np);
> +extern int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge);
>
>  extern int drm_encoder_init(struct drm_device *dev,
>                             struct drm_encoder *encoder,
> --
> 1.7.9.5
>