kernel/linux.git/include/linux/of_graph.h, branch v6.19.11

of: property: add of_graph_get_next_port_endpoint()

2024-10-24T21:35:48+00:00

We already have of_graph_get_next_endpoint(), but it is not intuitive to use in some case. (X) node { (Y) ports { (P0) port@0 { endpoint { remote-endpoint = ...; };}; (P10) port@1 { endpoint { remote-endpoint = ...; }; (P11) endpoint { remote-endpoint = ...; };}; (P2) port@2 { endpoint { remote-endpoint = ...; };}; }; }; For example, if I want to handle port@1's 2 endpoints (= P10, P11), I want to use like below P10 = of_graph_get_next_endpoint(port1, NULL); P11 = of_graph_get_next_endpoint(port1, P10); But 1st one will be error, because of_graph_get_next_endpoint() requested 1st parameter is "node" (X) or "ports" (Y), not but "port". Below works well, but it will get P0 P0 = of_graph_get_next_endpoint(node, NULL); P0 = of_graph_get_next_endpoint(ports, NULL); In other words, we can't handle P10/P11 directly via of_graph_get_next_endpoint(). There is another non intuitive behavior on of_graph_get_next_endpoint(). In case of if I could get P10 pointer for some way, and if I want to handle port@1 things by loop, I would like use it like below /* * "ep" is now P10, and handle port1 things here, * but we don't know how many endpoints port1 have. * * Because "ep" is non NULL now, we can use port1 * as of_graph_get_next_endpoint(port1, xxx) */ do { /* do something for port1 specific things here */ } while (ep = of_graph_get_next_endpoint(port1, ep)) But it also not worked as I expected. I expect it will be P10 -> P11 -> NULL, but it will be P10 -> P11 -> P2, because of_graph_get_next_endpoint() will fetch "endpoint" beyond the "port". It is not useful for generic driver. To handle endpoint more intuitive, create of_graph_get_next_port_endpoint() of_graph_get_next_port_endpoint(port1, NULL); // P10 of_graph_get_next_port_endpoint(port1, P10); // P11 of_graph_get_next_port_endpoint(port1, P11); // NULL Signed-off-by: Kuninori Morimoto Link: https://lore.kernel.org/r/87jzdyb5t5.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Rob Herring (Arm)

of: property: add of_graph_get_next_port()

2024-10-24T21:35:48+00:00

We have endpoint base functions - of_graph_get_next_endpoint() - of_graph_get_endpoint_count() - for_each_endpoint_of_node() Here, for_each_endpoint_of_node() loop finds each endpoints ports { port@0 { (1) endpoint {...}; }; port@1 { (2) endpoint {...}; }; ... }; In above case, it finds endpoint as (1) -> (2) -> ... Basically, user/driver knows which port is used for what, but not in all cases. For example on flexible/generic driver case, how many ports are used is not fixed. For example Sound Generic Card driver which is very flexible/generic and used from many venders can't know how many ports are used, and used for what, because it depends on each vender SoC and/or its used board. And more, the port can have multi endpoints. For example Generic Sound Card case, it supports many type of connection between CPU / Codec, and some of them uses multi endpoint in one port. see below. ports { (A) port@0 { (1) endpoint@0 {...}; (2) endpoint@1 {...}; }; (B) port@1 { (3) endpoint {...}; }; ... }; Generic Sound Card want to handle each connection via "port" base instead of "endpoint" base. But, it is very difficult to handle each "port" via existing for_each_endpoint_of_node(). Because getting each "port" via of_get_parent() from each "endpoint" doesn't work. For example in above case, both (1) (2) endpoint has same "port" (= A). Add "port" base functions. Signed-off-by: Kuninori Morimoto Link: https://lore.kernel.org/r/87ldyeb5t9.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Rob Herring (Arm)

of: property: use unsigned int return on of_graph_get_endpoint_count()

2024-02-06T22:20:24+00:00

Because of of_graph_get_endpoint_count() doesn't report error, just return count of endpoint, the return type should be unsigned. Tidyup it. Signed-off-by: Kuninori Morimoto Reviewed-by: Laurent Pinchart Link: https://lore.kernel.org/r/87plxbcvzb.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Rob Herring

of_graph: add of_graph_is_present()

2020-07-01T08:49:02+00:00

In some cases it's very useful to silently check whether port node exists at all in a device-tree before proceeding with parsing the graph. The DRM bridges code is one example of such case where absence of a graph in a device-tree is a legit condition. This patch adds of_graph_is_present() which returns true if given device-tree node contains OF graph port. Reviewed-by: Rob Herring Signed-off-by: Dmitry Osipenko Reviewed-by: Laurent Pinchart Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200701074232.13632-2-digetx@gmail.com

of: Use SPDX license tag for DT files

2018-01-08T14:22:45+00:00

Convert remaining DT files to use SPDX-License-Identifier tags. Cc: Benjamin Herrenschmidt Cc: Guennadi Liakhovetski Cc: Paul Mackerras Cc: Pantelis Antoniou Reviewed-by: Frank Rowand Reviewed-by: Philippe Ombredanne Signed-off-by: Rob Herring

of_graph: add of_graph_get_endpoint_count()

2017-05-17T09:21:16+00:00

OF graph want to count its endpoint number, same as of_get_child_count(). This patch adds of_graph_get_endpoint_count() Signed-off-by: Kuninori Morimoto Acked-by: Rob Herring Signed-off-by: Mark Brown

of_graph: add of_graph_get_port_parent()

2017-05-17T09:21:12+00:00

Linux kernel already has of_graph_get_remote_port_parent(), but, sometimes we want to get own port parent. This patch adds of_graph_get_port_parent() Signed-off-by: Kuninori Morimoto Acked-by: Rob Herring Signed-off-by: Mark Brown

of_graph: add of_graph_get_remote_endpoint()

2017-05-17T09:21:08+00:00

It should use same method to get same result. To getting remote-endpoint node, let's use of_graph_get_remote_endpoint() Signed-off-by: Kuninori Morimoto Acked-by: Rob Herring Signed-off-by: Mark Brown

of: introduce of_graph_get_remote_node

2017-02-15T14:53:32+00:00

The OF graph API leaves too much of the graph walking to clients when in many cases the driver doesn't care about accessing the port or endpoint nodes. The drivers typically just want the device connected via a particular graph connection. of_graph_get_remote_node provides this functionality. Signed-off-by: Rob Herring Acked-by: Philipp Zabel

of: include errno.h in of_graph.h

2016-05-02T14:00:56+00:00

When CONFIG_OF is disabled, we have to include linux/errno.h before including of_graph.h, or get build errors like in the newly added sun4i drm driver: In file included from ../drivers/gpu/drm/sun4i/sun4i_drv.c:14:0: include/linux/of_graph.h: In function 'of_graph_parse_endpoint': include/linux/of_graph.h:58:10: error: 'ENOSYS' undeclared (first use in this function) A better solution is to ensure that the header can be included by itself, so let's include linux/errno.h here to fix the error we just got, and any similar future error. Signed-off-by: Arnd Bergmann Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support") Signed-off-by: Rob Herring