On Fri, Sep 10, 2021 at 03:09:39PM +0200, Maxime Ripard wrote: > Display drivers so far need to have a lot of boilerplate to first > retrieve either the panel or bridge that they are connected to using > drm_of_find_panel_or_bridge(), and then either deal with each with ad-hoc > functions or create a drm panel bridge through drm_panel_bridge_add. > > In order to reduce the boilerplate and hopefully create a path of least > resistance towards using the DRM panel bridge layer, let's create the > function devm_drm_of_get_next to reduce that boilerplate. > > Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> > --- > drivers/gpu/drm/drm_bridge.c | 42 ++++++++++++++++++++++++++++++++---- > drivers/gpu/drm/drm_of.c | 3 +++ > include/drm/drm_bridge.h | 2 ++ > 3 files changed, 43 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c > index a8ed66751c2d..10ddca4638b0 100644 > --- a/drivers/gpu/drm/drm_bridge.c > +++ b/drivers/gpu/drm/drm_bridge.c > @@ -28,6 +28,7 @@ > #include <drm/drm_atomic_state_helper.h> > #include <drm/drm_bridge.h> > #include <drm/drm_encoder.h> > +#include <drm/drm_of.h> > #include <drm/drm_print.h> > > #include "drm_crtc_internal.h" > @@ -51,10 +52,8 @@ > * > * Display drivers are responsible for linking encoders with the first bridge > * in the chains. This is done by acquiring the appropriate bridge with > - * of_drm_find_bridge() or drm_of_find_panel_or_bridge(), or creating it for a > - * panel with drm_panel_bridge_add_typed() (or the managed version > - * devm_drm_panel_bridge_add_typed()). Once acquired, the bridge shall be > - * attached to the encoder with a call to drm_bridge_attach(). > + * devm_drm_of_get_bridge(). Once acquired, the bridge shall be attached to the > + * encoder with a call to drm_bridge_attach(). > * > * Bridges are responsible for linking themselves with the next bridge in the > * chain, if any. This is done the same way as for encoders, with the call to > @@ -1233,6 +1232,41 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np) > return NULL; > } > EXPORT_SYMBOL(of_drm_find_bridge); > + > +/** > + * devm_drm_of_get_bridge - Return next bridge in the chain > + * @dev: device to tie the bridge lifetime to > + * @np: device tree node containing encoder output ports > + * @port: port in the device tree node > + * @endpoint: endpoint in the device tree node > + * > + * Given a DT node's port and endpoint number, finds the connected node > + * and returns the associated bridge if any, or creates and returns a > + * drm panel bridge instance if a panel is connected. > + * > + * Returns a pointer to the bridge if successful, or an error pointer > + * otherwise. > + */ > +struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, > + struct device_node *np, > + unsigned int port, > + unsigned int endpoint) One extra comment. In of_graph_get_remote_node() port is u32 In drm_of_find_panel_or_bridge() port is int Here port is unsigned int My OCD would benefit if we used u32 here - as this is consistent with the base function of_graph_get_remote_node(). Sam > +{ > + struct drm_bridge *bridge; > + struct drm_panel *panel; > + int ret; > + > + ret = drm_of_find_panel_or_bridge(np, port, endpoint, > + &panel, &bridge); > + if (ret) > + return ERR_PTR(ret); > + > + if (panel) > + bridge = devm_drm_panel_bridge_add(dev, panel); > + > + return bridge; > +} > +EXPORT_SYMBOL(devm_drm_of_get_bridge); > #endif > > MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@xxxxxxxxxxx>"); > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > index 997b8827fed2..37c34146eea8 100644 > --- a/drivers/gpu/drm/drm_of.c > +++ b/drivers/gpu/drm/drm_of.c > @@ -231,6 +231,9 @@ EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); > * return either the associated struct drm_panel or drm_bridge device. Either > * @panel or @bridge must not be NULL. > * > + * This function is deprecated and should not be used in new drivers. Use > + * devm_drm_of_get_bridge() instead. > + * > * Returns zero if successful, or one of the standard error codes if it fails. > */ > int drm_of_find_panel_or_bridge(const struct device_node *np, > diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h > index 46bdfa48c413..f70c88ca96ef 100644 > --- a/include/drm/drm_bridge.h > +++ b/include/drm/drm_bridge.h > @@ -911,6 +911,8 @@ struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, > struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev, > struct drm_panel *panel, > u32 connector_type); > +struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node, > + unsigned int port, unsigned int endpoint); > struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge); > #endif > > -- > 2.31.1