Re: [PATCH v2 1/2] drm: Add drm_bridge

[Rob Clark <robdclark@gmail.com>]

On Thu, Aug 29, 2013 at 11:59 AM, Sean Paul <seanpaul@chromium.org> wrote:
> On Wed, Aug 14, 2013 at 4:47 PM, Sean Paul <seanpaul@chromium.org> wrote:
>> This patch adds the notion of a drm_bridge. A bridge is a chained
>> device which hangs off an encoder. The drm driver using the bridge
>> should provide the association between encoder and bridge. Once a
>> bridge is associated with an encoder, it will participate in mode
>> set, and dpms (via the enable/disable hooks).
>>
>
> Friendly ping. Any feedback?

It looks good to me, although unfortunately I've not had a chance to
rebase on this version.  I'll try to make some time to do that in the
next few days.

BR,
-R

> Sean
>
>
>> Signed-off-by: Sean Paul <seanpaul@chromium.org>
>> ---
>>  drivers/gpu/drm/drm_crtc.c        | 50 ++++++++++++++++++++++
>>  drivers/gpu/drm/drm_crtc_helper.c | 89 ++++++++++++++++++++++++++++++---------
>>  include/drm/drm_crtc.h            | 55 ++++++++++++++++++++++++
>>  3 files changed, 175 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
>> index fc83bb9..0311e2b 100644
>> --- a/drivers/gpu/drm/drm_crtc.c
>> +++ b/drivers/gpu/drm/drm_crtc.c
>> @@ -781,6 +781,41 @@ void drm_connector_unplug_all(struct drm_device *dev)
>>  }
>>  EXPORT_SYMBOL(drm_connector_unplug_all);
>>
>> +int drm_bridge_init(struct drm_device *dev, struct drm_bridge *bridge,
>> +               const struct drm_bridge_funcs *funcs)
>> +{
>> +       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;
>> +       bridge->funcs = funcs;
>> +
>> +       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);
>> +
>> +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);
>> +
>>  int drm_encoder_init(struct drm_device *dev,
>>                       struct drm_encoder *encoder,
>>                       const struct drm_encoder_funcs *funcs,
>> @@ -1190,6 +1225,7 @@ 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)
>> @@ -1198,6 +1234,7 @@ 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;
>>  }
>>
>> @@ -1207,6 +1244,7 @@ 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)))
>> @@ -1223,6 +1261,11 @@ 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);
>> @@ -3905,6 +3948,7 @@ 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);
>> @@ -3941,6 +3985,7 @@ 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;
>> @@ -3951,6 +3996,11 @@ 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/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
>> index 6a64749..c722c3b 100644
>> --- a/drivers/gpu/drm/drm_crtc_helper.c
>> +++ b/drivers/gpu/drm/drm_crtc_helper.c
>> @@ -257,10 +257,16 @@ drm_encoder_disable(struct drm_encoder *encoder)
>>  {
>>         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>>
>> +       if (encoder->bridge)
>> +               encoder->bridge->funcs->disable(encoder->bridge);
>> +
>>         if (encoder_funcs->disable)
>>                 (*encoder_funcs->disable)(encoder);
>>         else
>>                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
>> +
>> +       if (encoder->bridge)
>> +               encoder->bridge->funcs->post_disable(encoder->bridge);
>>  }
>>
>>  /**
>> @@ -424,6 +430,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>
>>                 if (encoder->crtc != crtc)
>>                         continue;
>> +
>> +               if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
>> +                       ret = encoder->bridge->funcs->mode_fixup(
>> +                                       encoder->bridge, mode, adjusted_mode);
>> +                       if (!ret) {
>> +                               DRM_DEBUG_KMS("Bridge fixup failed\n");
>> +                               goto done;
>> +                       }
>> +               }
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
>>                                                       adjusted_mode))) {
>> @@ -443,9 +459,16 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>
>>                 if (encoder->crtc != crtc)
>>                         continue;
>> +
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->disable(encoder->bridge);
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 /* Disable the encoders as the first thing we do. */
>>                 encoder_funcs->prepare(encoder);
>> +
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->post_disable(encoder->bridge);
>>         }
>>
>>         drm_crtc_prepare_encoders(dev);
>> @@ -469,6 +492,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>                         mode->base.id, mode->name);
>>                 encoder_funcs = encoder->helper_private;
>>                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
>> +
>> +               if (encoder->bridge && encoder->bridge->funcs->mode_set)
>> +                       encoder->bridge->funcs->mode_set(encoder->bridge, mode,
>> +                                       adjusted_mode);
>>         }
>>
>>         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
>> @@ -479,9 +506,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>                 if (encoder->crtc != crtc)
>>                         continue;
>>
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->pre_enable(encoder->bridge);
>> +
>>                 encoder_funcs = encoder->helper_private;
>>                 encoder_funcs->commit(encoder);
>>
>> +               if (encoder->bridge)
>> +                       encoder->bridge->funcs->enable(encoder->bridge);
>>         }
>>
>>         /* Store real post-adjustment hardware mode. */
>> @@ -830,6 +862,31 @@ static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
>>         return dpms;
>>  }
>>
>> +/* Helper which handles bridge ordering around encoder dpms */
>> +static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
>> +{
>> +       struct drm_bridge *bridge = encoder->bridge;
>> +       struct drm_encoder_helper_funcs *encoder_funcs;
>> +
>> +       if (bridge) {
>> +               if (mode == DRM_MODE_DPMS_ON)
>> +                       bridge->funcs->pre_enable(bridge);
>> +               else
>> +                       bridge->funcs->disable(bridge);
>> +       }
>> +
>> +       encoder_funcs = encoder->helper_private;
>> +       if (encoder_funcs->dpms)
>> +               encoder_funcs->dpms(encoder, mode);
>> +
>> +       if (bridge) {
>> +               if (mode == DRM_MODE_DPMS_ON)
>> +                       bridge->funcs->enable(bridge);
>> +               else
>> +                       bridge->funcs->post_disable(bridge);
>> +       }
>> +}
>> +
>>  static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
>>  {
>>         int dpms = DRM_MODE_DPMS_OFF;
>> @@ -857,7 +914,7 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>  {
>>         struct drm_encoder *encoder = connector->encoder;
>>         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
>> -       int old_dpms;
>> +       int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
>>
>>         if (mode == connector->dpms)
>>                 return;
>> @@ -865,6 +922,9 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>         old_dpms = connector->dpms;
>>         connector->dpms = mode;
>>
>> +       if (encoder)
>> +               encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
>> +
>>         /* from off to on, do crtc then encoder */
>>         if (mode < old_dpms) {
>>                 if (crtc) {
>> @@ -873,22 +933,14 @@ void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
>>                                 (*crtc_funcs->dpms) (crtc,
>>                                                      drm_helper_choose_crtc_dpms(crtc));
>>                 }
>> -               if (encoder) {
>> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>> -                       if (encoder_funcs->dpms)
>> -                               (*encoder_funcs->dpms) (encoder,
>> -                                                       drm_helper_choose_encoder_dpms(encoder));
>> -               }
>> +               if (encoder)
>> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>>         }
>>
>>         /* from on to off, do encoder then crtc */
>>         if (mode > old_dpms) {
>> -               if (encoder) {
>> -                       struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>> -                       if (encoder_funcs->dpms)
>> -                               (*encoder_funcs->dpms) (encoder,
>> -                                                       drm_helper_choose_encoder_dpms(encoder));
>> -               }
>> +               if (encoder)
>> +                       drm_helper_encoder_dpms(encoder, encoder_dpms);
>>                 if (crtc) {
>>                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
>>                         if (crtc_funcs->dpms)
>> @@ -924,9 +976,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>>  {
>>         struct drm_crtc *crtc;
>>         struct drm_encoder *encoder;
>> -       struct drm_encoder_helper_funcs *encoder_funcs;
>>         struct drm_crtc_helper_funcs *crtc_funcs;
>> -       int ret;
>> +       int ret, encoder_dpms;
>>
>>         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
>>
>> @@ -946,10 +997,10 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
>>                                 if(encoder->crtc != crtc)
>>                                         continue;
>>
>> -                               encoder_funcs = encoder->helper_private;
>> -                               if (encoder_funcs->dpms)
>> -                                       (*encoder_funcs->dpms) (encoder,
>> -                                                               drm_helper_choose_encoder_dpms(encoder));
>> +                               encoder_dpms = drm_helper_choose_encoder_dpms(
>> +                                                       encoder);
>> +
>> +                               drm_helper_encoder_dpms(encoder, encoder_dpms);
>>                         }
>>
>>                         crtc_funcs = crtc->helper_private;
>> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
>> index fa12a2f..a26d3d9 100644
>> --- a/include/drm/drm_crtc.h
>> +++ b/include/drm/drm_crtc.h
>> @@ -49,6 +49,7 @@ struct drm_clip_rect;
>>  #define DRM_MODE_OBJECT_FB 0xfbfbfbfb
>>  #define DRM_MODE_OBJECT_BLOB 0xbbbbbbbb
>>  #define DRM_MODE_OBJECT_PLANE 0xeeeeeeee
>> +#define DRM_MODE_OBJECT_BRIDGE 0xbdbdbdbd
>>
>>  struct drm_mode_object {
>>         uint32_t id;
>> @@ -305,6 +306,7 @@ struct drm_connector;
>>  struct drm_encoder;
>>  struct drm_pending_vblank_event;
>>  struct drm_plane;
>> +struct drm_bridge;
>>
>>  /**
>>   * drm_crtc_funcs - control CRTCs for a given device
>> @@ -507,6 +509,7 @@ struct drm_encoder_funcs {
>>   * @possible_crtcs: bitmask of potential CRTC bindings
>>   * @possible_clones: bitmask of potential sibling encoders for cloning
>>   * @crtc: currently bound CRTC
>> + * @bridge: bridge associated to the encoder
>>   * @funcs: control functions
>>   * @helper_private: mid-layer private data
>>   *
>> @@ -523,6 +526,7 @@ struct drm_encoder {
>>         uint32_t possible_clones;
>>
>>         struct drm_crtc *crtc;
>> +       struct drm_bridge *bridge;
>>         const struct drm_encoder_funcs *funcs;
>>         void *helper_private;
>>  };
>> @@ -683,6 +687,48 @@ struct drm_plane {
>>  };
>>
>>  /**
>> + * drm_bridge_funcs - drm_bridge control functions
>> + * @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 {
>> +       bool (*mode_fixup)(struct drm_bridge *bridge,
>> +                          const struct drm_display_mode *mode,
>> +                          struct drm_display_mode *adjusted_mode);
>> +       void (*disable)(struct drm_bridge *bridge);
>> +       void (*post_disable)(struct drm_bridge *bridge);
>> +       void (*mode_set)(struct drm_bridge *bridge,
>> +                        struct drm_display_mode *mode,
>> +                        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
>> + * @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;
>> +
>> +       const struct drm_bridge_funcs *funcs;
>> +       void *driver_private;
>> +};
>> +
>> +/**
>>   * drm_mode_set - new values for a CRTC config change
>>   * @head: list management
>>   * @fb: framebuffer to use for new config
>> @@ -742,6 +788,7 @@ 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;
>> @@ -756,6 +803,8 @@ 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
>> @@ -793,6 +842,8 @@ 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;
>>         int num_plane;
>> @@ -878,6 +929,10 @@ extern void drm_connector_cleanup(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,
>> +                          const struct drm_bridge_funcs *funcs);
>> +extern void drm_bridge_cleanup(struct drm_bridge *bridge);
>> +
>>  extern int drm_encoder_init(struct drm_device *dev,
>>                             struct drm_encoder *encoder,
>>                             const struct drm_encoder_funcs *funcs,
>> --
>> 1.8.3
>>