| Message ID | 20200617222703.17080-2-digetx@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Support DRM bridges on NVIDIA Tegra | expand |
On Thu, Jun 18, 2020 at 01:26:57AM +0300, Dmitry Osipenko wrote: > In some case, like a DRM display code for example, it's useful to silently > check whether port node exists at all in a device-tree before proceeding > with parsing of the graph. > > This patch adds of_graph_presents() that returns true if given device-tree > node contains OF graph port. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/of/property.c | 52 +++++++++++++++++++++++++++++++++------- > include/linux/of_graph.h | 6 +++++ > 2 files changed, 49 insertions(+), 9 deletions(-) > > diff --git a/drivers/of/property.c b/drivers/of/property.c > index 1f2086f4e7ce..b84ed6a7cf50 100644 > --- a/drivers/of/property.c > +++ b/drivers/of/property.c > @@ -29,6 +29,48 @@ > > #include "of_private.h" > > +/** > + * of_graph_get_first_local_port() - get first local port node > + * @node: pointer to a local endpoint device_node > + * > + * Return: First local port node associated with local endpoint node linked > + * to @node. Use of_node_put() on it when done. > + */ > +static struct device_node * > +of_graph_get_first_local_port(const struct device_node *node) > +{ > + struct device_node *ports, *port; > + > + ports = of_get_child_by_name(node, "ports"); > + if (ports) > + node = ports; > + > + port = of_get_child_by_name(node, "port"); > + of_node_put(ports); > + > + return port; > +} > + > +/** > + * of_graph_presents() - check graph's presence > + * @node: pointer to a device_node checked for the graph's presence > + * > + * Return: True if @node has a port or ports sub-node, false otherwise. > + */ > +bool of_graph_presents(const struct device_node *node) of_graph_is_present Otherwise, Reviewed-by: Rob Herring <robh@kernel.org>
30.06.2020 02:12, Rob Herring пишет: > On Thu, Jun 18, 2020 at 01:26:57AM +0300, Dmitry Osipenko wrote: >> In some case, like a DRM display code for example, it's useful to silently >> check whether port node exists at all in a device-tree before proceeding >> with parsing of the graph. >> >> This patch adds of_graph_presents() that returns true if given device-tree >> node contains OF graph port. >> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >> --- >> drivers/of/property.c | 52 +++++++++++++++++++++++++++++++++------- >> include/linux/of_graph.h | 6 +++++ >> 2 files changed, 49 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/of/property.c b/drivers/of/property.c >> index 1f2086f4e7ce..b84ed6a7cf50 100644 >> --- a/drivers/of/property.c >> +++ b/drivers/of/property.c >> @@ -29,6 +29,48 @@ >> >> #include "of_private.h" >> >> +/** >> + * of_graph_get_first_local_port() - get first local port node >> + * @node: pointer to a local endpoint device_node >> + * >> + * Return: First local port node associated with local endpoint node linked >> + * to @node. Use of_node_put() on it when done. >> + */ >> +static struct device_node * >> +of_graph_get_first_local_port(const struct device_node *node) >> +{ >> + struct device_node *ports, *port; >> + >> + ports = of_get_child_by_name(node, "ports"); >> + if (ports) >> + node = ports; >> + >> + port = of_get_child_by_name(node, "port"); >> + of_node_put(ports); >> + >> + return port; >> +} >> + >> +/** >> + * of_graph_presents() - check graph's presence >> + * @node: pointer to a device_node checked for the graph's presence >> + * >> + * Return: True if @node has a port or ports sub-node, false otherwise. >> + */ >> +bool of_graph_presents(const struct device_node *node) > > of_graph_is_present > > Otherwise, > > Reviewed-by: Rob Herring <robh@kernel.org> > Thanks! I'll address the comment and then factor out this and the drm_of_find_panel_or_bridge() changes into a separate series in v9, since the Tegra DRM patches could be applied separately by Thierry.
diff --git a/drivers/of/property.c b/drivers/of/property.c index 1f2086f4e7ce..b84ed6a7cf50 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -29,6 +29,48 @@ #include "of_private.h" +/** + * of_graph_get_first_local_port() - get first local port node + * @node: pointer to a local endpoint device_node + * + * Return: First local port node associated with local endpoint node linked + * to @node. Use of_node_put() on it when done. + */ +static struct device_node * +of_graph_get_first_local_port(const struct device_node *node) +{ + struct device_node *ports, *port; + + ports = of_get_child_by_name(node, "ports"); + if (ports) + node = ports; + + port = of_get_child_by_name(node, "port"); + of_node_put(ports); + + return port; +} + +/** + * of_graph_presents() - check graph's presence + * @node: pointer to a device_node checked for the graph's presence + * + * Return: True if @node has a port or ports sub-node, false otherwise. + */ +bool of_graph_presents(const struct device_node *node) +{ + struct device_node *local; + + local = of_graph_get_first_local_port(node); + if (!local) + return false; + + of_node_put(local); + + return true; +} +EXPORT_SYMBOL(of_graph_presents); + /** * of_property_count_elems_of_size - Count the number of elements in a property * @@ -608,15 +650,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, * parent port node. */ if (!prev) { - struct device_node *node; - - node = of_get_child_by_name(parent, "ports"); - if (node) - parent = node; - - port = of_get_child_by_name(parent, "port"); - of_node_put(node); - + port = of_graph_get_first_local_port(parent); if (!port) { pr_err("graph: no port node found in %pOF\n", parent); return NULL; diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h index 01038a6aade0..cc3028a0659d 100644 --- a/include/linux/of_graph.h +++ b/include/linux/of_graph.h @@ -38,6 +38,7 @@ struct of_endpoint { child = of_graph_get_next_endpoint(parent, child)) #ifdef CONFIG_OF +bool of_graph_presents(const struct device_node *node); int of_graph_parse_endpoint(const struct device_node *node, struct of_endpoint *endpoint); int of_graph_get_endpoint_count(const struct device_node *np); @@ -56,6 +57,11 @@ struct device_node *of_graph_get_remote_node(const struct device_node *node, u32 port, u32 endpoint); #else +static inline bool of_graph_presents(const struct device_node *node) +{ + return false; +} + static inline int of_graph_parse_endpoint(const struct device_node *node, struct of_endpoint *endpoint) {
In some case, like a DRM display code for example, it's useful to silently check whether port node exists at all in a device-tree before proceeding with parsing of the graph. This patch adds of_graph_presents() that returns true if given device-tree node contains OF graph port. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/of/property.c | 52 +++++++++++++++++++++++++++++++++------- include/linux/of_graph.h | 6 +++++ 2 files changed, 49 insertions(+), 9 deletions(-)