| Message ID | 20211207054747.461029-2-jagan@amarulasolutions.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: of: Lookup child panel_or_bridge | expand |
On Mon, Dec 6, 2021 at 11:49 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > Add of_get_non_port_child() helper that can be used to lookup > non port child nodes. > > Some OF graphs don't require 'ports' to represent the next output > instead, it simply adds a child node on a given parent node. This > helper lookup that child node, however that child node is not a > 'port' on given parent as 'port' based nodes are looked up via > of_graph_get_remote_node(). > > Example OF graph representation of DSI host, which doesn't > have 'ports'. This seems pretty specific to DSI and also can't handle there being more than 1 non-port node. That's allowed for DSI too, but I don't think I've ever seen a case. Anyways, I'd just move this to DRM rather than common DT code. One comment on the implementation that will shrink it. > > dsi { > #address-cells = <1>; > #size-cells = <0>; > > port { > dsi_in_tcon0: endpoint { > remote-endpoint = <tcon0_out_dsi>; > }; > > panel@0 { > reg = <0>; > }; > }; > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> > --- > drivers/of/base.c | 29 +++++++++++++++++++++++++++++ > include/linux/of.h | 6 ++++++ > 2 files changed, 35 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 61de453b885c..31bbf885b0f8 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -854,6 +854,35 @@ struct device_node *of_get_compatible_child(const struct device_node *parent, > } > EXPORT_SYMBOL(of_get_compatible_child); > > +/** > + * of_get_non_port_child - Find the non port child node for a given parent > + * @node: parent node > + * > + * This function looks for child node which is not port child for given parent. > + * > + * Return: A node pointer if found, with refcount incremented, use > + * of_node_put() on it when done. > + * Returns NULL if node is not found. > + */ > +struct device_node *of_get_non_port_child(const struct device_node *parent) > +{ > + struct device_node *child; > + > + for_each_child_of_node(parent, child) { for_each_available_child_of_node > + if (of_node_name_eq(child, "port")) > + continue; > + > + if (!of_device_is_available(child)) { > + of_node_put(child); > + continue; > + } > + break; > + } > + > + return child; > +} > +EXPORT_SYMBOL(of_get_non_port_child); > + > /** > * of_get_child_by_name - Find the child node by name for a given parent > * @node: parent node > diff --git a/include/linux/of.h b/include/linux/of.h > index ff143a027abc..3e699becef82 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -290,6 +290,7 @@ extern struct device_node *of_get_next_child(const struct device_node *node, > extern struct device_node *of_get_next_available_child( > const struct device_node *node, struct device_node *prev); > > +extern struct device_node *of_get_non_port_child(const struct device_node *parent); > extern struct device_node *of_get_compatible_child(const struct device_node *parent, > const char *compatible); > extern struct device_node *of_get_child_by_name(const struct device_node *node, > @@ -678,6 +679,11 @@ static inline bool of_have_populated_dt(void) > return false; > } > > +static inline struct device_node *of_get_non_port_child(const struct device_node *parent) > +{ > + return NULL; > +} > + > static inline struct device_node *of_get_compatible_child(const struct device_node *parent, > const char *compatible) > { > -- > 2.25.1 >
On Wed, Dec 8, 2021 at 2:20 AM Rob Herring <robh+dt@kernel.org> wrote: > > On Mon, Dec 6, 2021 at 11:49 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > > > Add of_get_non_port_child() helper that can be used to lookup > > non port child nodes. > > > > Some OF graphs don't require 'ports' to represent the next output > > instead, it simply adds a child node on a given parent node. This > > helper lookup that child node, however that child node is not a > > 'port' on given parent as 'port' based nodes are looked up via > > of_graph_get_remote_node(). > > > > Example OF graph representation of DSI host, which doesn't > > have 'ports'. > > This seems pretty specific to DSI and also can't handle there being > more than 1 non-port node. That's allowed for DSI too, but I don't > think I've ever seen a case. Anyways, I'd just move this to DRM rather > than common DT code. One comment on the implementation that will > shrink it. I think it can be possible to OF graph even for non-DSI, however if the end-node outputs to a panel or bridge. At the moment, I can one use case on the non-DSI side is rcar du encoder. https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/gpu/drm/rcar-du/rcar_du_encoder.c#n68 I'm not sure this can be done existing of_graph_get_remote_node, but an example. > > > > > dsi { > > #address-cells = <1>; > > #size-cells = <0>; > > > > port { > > dsi_in_tcon0: endpoint { > > remote-endpoint = <tcon0_out_dsi>; > > }; > > > > panel@0 { > > reg = <0>; > > }; > > }; > > > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> > > --- > > drivers/of/base.c | 29 +++++++++++++++++++++++++++++ > > include/linux/of.h | 6 ++++++ > > 2 files changed, 35 insertions(+) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index 61de453b885c..31bbf885b0f8 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -854,6 +854,35 @@ struct device_node *of_get_compatible_child(const struct device_node *parent, > > } > > EXPORT_SYMBOL(of_get_compatible_child); > > > > +/** > > + * of_get_non_port_child - Find the non port child node for a given parent > > + * @node: parent node > > + * > > + * This function looks for child node which is not port child for given parent. > > + * > > + * Return: A node pointer if found, with refcount incremented, use > > + * of_node_put() on it when done. > > + * Returns NULL if node is not found. > > + */ > > +struct device_node *of_get_non_port_child(const struct device_node *parent) > > +{ > > + struct device_node *child; > > + > > + for_each_child_of_node(parent, child) { > > for_each_available_child_of_node Look like this simplifies not required to use of_device_is_available, I will use it in v2. Thanks, Jagan.
Hi Rob and Laurent, On Wed, Dec 8, 2021 at 11:56 AM Jagan Teki <jagan@amarulasolutions.com> wrote: > > On Wed, Dec 8, 2021 at 2:20 AM Rob Herring <robh+dt@kernel.org> wrote: > > > > On Mon, Dec 6, 2021 at 11:49 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > > > > > Add of_get_non_port_child() helper that can be used to lookup > > > non port child nodes. > > > > > > Some OF graphs don't require 'ports' to represent the next output > > > instead, it simply adds a child node on a given parent node. This > > > helper lookup that child node, however that child node is not a > > > 'port' on given parent as 'port' based nodes are looked up via > > > of_graph_get_remote_node(). > > > > > > Example OF graph representation of DSI host, which doesn't > > > have 'ports'. > > > > This seems pretty specific to DSI and also can't handle there being > > more than 1 non-port node. That's allowed for DSI too, but I don't > > think I've ever seen a case. Anyways, I'd just move this to DRM rather > > than common DT code. One comment on the implementation that will > > shrink it. > > I think it can be possible to OF graph even for non-DSI, however if > the end-node outputs to a panel or bridge. At the moment, I can one > use case on the non-DSI side is rcar du encoder. > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/gpu/drm/rcar-du/rcar_du_encoder.c#n68 Do you see any point to make this helper in of/base based on above rcar_du_encoder usage? if not i can directly use this functionality in panel_or_bridge finding code itself. Please let me know. Thanks, Jagan.
diff --git a/drivers/of/base.c b/drivers/of/base.c index 61de453b885c..31bbf885b0f8 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -854,6 +854,35 @@ struct device_node *of_get_compatible_child(const struct device_node *parent, } EXPORT_SYMBOL(of_get_compatible_child); +/** + * of_get_non_port_child - Find the non port child node for a given parent + * @node: parent node + * + * This function looks for child node which is not port child for given parent. + * + * Return: A node pointer if found, with refcount incremented, use + * of_node_put() on it when done. + * Returns NULL if node is not found. + */ +struct device_node *of_get_non_port_child(const struct device_node *parent) +{ + struct device_node *child; + + for_each_child_of_node(parent, child) { + if (of_node_name_eq(child, "port")) + continue; + + if (!of_device_is_available(child)) { + of_node_put(child); + continue; + } + break; + } + + return child; +} +EXPORT_SYMBOL(of_get_non_port_child); + /** * of_get_child_by_name - Find the child node by name for a given parent * @node: parent node diff --git a/include/linux/of.h b/include/linux/of.h index ff143a027abc..3e699becef82 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -290,6 +290,7 @@ extern struct device_node *of_get_next_child(const struct device_node *node, extern struct device_node *of_get_next_available_child( const struct device_node *node, struct device_node *prev); +extern struct device_node *of_get_non_port_child(const struct device_node *parent); extern struct device_node *of_get_compatible_child(const struct device_node *parent, const char *compatible); extern struct device_node *of_get_child_by_name(const struct device_node *node, @@ -678,6 +679,11 @@ static inline bool of_have_populated_dt(void) return false; } +static inline struct device_node *of_get_non_port_child(const struct device_node *parent) +{ + return NULL; +} + static inline struct device_node *of_get_compatible_child(const struct device_node *parent, const char *compatible) {
Add of_get_non_port_child() helper that can be used to lookup non port child nodes. Some OF graphs don't require 'ports' to represent the next output instead, it simply adds a child node on a given parent node. This helper lookup that child node, however that child node is not a 'port' on given parent as 'port' based nodes are looked up via of_graph_get_remote_node(). Example OF graph representation of DSI host, which doesn't have 'ports'. dsi { #address-cells = <1>; #size-cells = <0>; port { dsi_in_tcon0: endpoint { remote-endpoint = <tcon0_out_dsi>; }; panel@0 { reg = <0>; }; }; Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> --- drivers/of/base.c | 29 +++++++++++++++++++++++++++++ include/linux/of.h | 6 ++++++ 2 files changed, 35 insertions(+)