| Message ID | 87bk95klgc.wl-kuninori.morimoto.gx@renesas.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | of: property: add port base loop | expand |
On 29/01/2024 02:54, Kuninori Morimoto wrote: > We already have of_graph_get_next_endpoint(), but it is not intuitive > to use. > > (X) node { > (Y) ports { > port@0 { endpoint { remote-endpoint = ...; };}; > (A1) port@1 { endpoint { remote-endpoint = ...; }; > (A2) endpoint { remote-endpoint = ...; };}; > (B) port@2 { endpoint { remote-endpoint = ...; };}; > }; > }; > > For example, if I want to handle port@1's 2 endpoints (= A1, A2), > I want to use like below > > A1 = of_graph_get_next_endpoint(port1, NULL); > A2 = of_graph_get_next_endpoint(port1, A1); > > But 1st one will be error, because of_graph_get_next_endpoint() requested > "parent" means "node" (X) or "ports" (Y), not "port". > Below are OK > > of_graph_get_next_endpoint(node, NULL); // node/ports/port@0/endpoint > of_graph_get_next_endpoint(ports, NULL); // node/ports/port@0/endpoint > > In other words, we can't handle A1/A2 directly via > of_graph_get_next_endpoint() so far. > > There is another non intuitive behavior on of_graph_get_next_endpoint(). > In case of if I could get A1 pointer for some way, and if I want to > handle port@1 things, I would like use it like below > > /* > * "endpoint" is now A1, and handle port1 things here, > * but we don't know how many endpoints port1 has. > * > * Because "endpoint" is non NULL, we can use port1 > * as of_graph_get_next_endpoint(port1, xxx) > */ > do { > /* do something for port1 specific things here */ > } while (endpoint = of_graph_get_next_endpoint(port1, endpoint)) > > But it also not worked as I expected. > I expect it will be A1 -> A2 -> NULL, > but it will be A1 -> A2 -> B, because of_graph_get_next_endpoint() > will fetch endpoint beyond the port. > > It is not useful on generic driver like Generic Sound Card. > It uses of_get_next_child() instead for now, but it is not intuitive, > and not check node name (= "endpoint"). > > To handle endpoint more intuitive, create of_graph_get_next_endpoint_raw() > > of_graph_get_next_endpoint_raw(port1, NULL); // A1 > of_graph_get_next_endpoint_raw(port1, A1); // A2 > of_graph_get_next_endpoint_raw(port1, A2); // NULL > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > --- > drivers/of/property.c | 26 +++++++++++++++++++++++++- > include/linux/of_graph.h | 2 ++ > 2 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/property.c b/drivers/of/property.c > index 14ffd199c9b1..37dbb1b0e742 100644 > --- a/drivers/of/property.c > +++ b/drivers/of/property.c > @@ -667,6 +667,30 @@ struct device_node *of_graph_get_next_port(const struct device_node *parent, > } > EXPORT_SYMBOL(of_graph_get_next_port); > > +/** > + * of_graph_get_next_endpoint_raw() - get next endpoint node How about "of_graph_get_next_port_endpoint()"? > + * @port: pointer to the target port node > + * @endpoint: current endpoint node, or NULL to get first > + * > + * Return: An 'endpoint' node pointer with refcount incremented. Refcount > + * of the passed @prev node is decremented. > + */ It might be good to highlight here the difference to the of_graph_get_next_endpoint(). > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > + struct device_node *endpoint) > +{ > + if (!port) > + return NULL; > + > + do { > + endpoint = of_get_next_child(port, endpoint); > + if (!endpoint) > + break; > + } while (!of_node_name_eq(endpoint, "endpoint")); > + > + return endpoint; > +} > +EXPORT_SYMBOL(of_graph_get_next_endpoint_raw); > + > /** > * of_graph_get_next_endpoint() - get next endpoint node > * @parent: pointer to the parent device node > @@ -708,7 +732,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > * getting the next child. If the previous endpoint is NULL this > * will return the first child. > */ > - endpoint = of_get_next_child(port, prev); > + endpoint = of_graph_get_next_endpoint_raw(port, prev); > if (endpoint) { > of_node_put(port); > return endpoint; > diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h > index fff598640e93..427905a6e8c3 100644 > --- a/include/linux/of_graph.h > +++ b/include/linux/of_graph.h > @@ -57,6 +57,8 @@ int of_graph_get_port_count(const struct device_node *np); > struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id); > struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > struct device_node *previous); > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > + struct device_node *prev); > struct device_node *of_graph_get_next_port(const struct device_node *parent, > struct device_node *previous); > struct device_node *of_graph_get_endpoint_by_regs(
On Mon, Jan 29, 2024 at 02:29:22PM +0200, Tomi Valkeinen wrote: > On 29/01/2024 02:54, Kuninori Morimoto wrote: > > We already have of_graph_get_next_endpoint(), but it is not intuitive > > to use. > > > > (X) node { > > (Y) ports { > > port@0 { endpoint { remote-endpoint = ...; };}; > > (A1) port@1 { endpoint { remote-endpoint = ...; }; > > (A2) endpoint { remote-endpoint = ...; };}; > > (B) port@2 { endpoint { remote-endpoint = ...; };}; > > }; > > }; > > > > For example, if I want to handle port@1's 2 endpoints (= A1, A2), > > I want to use like below > > > > A1 = of_graph_get_next_endpoint(port1, NULL); > > A2 = of_graph_get_next_endpoint(port1, A1); > > > > But 1st one will be error, because of_graph_get_next_endpoint() requested > > "parent" means "node" (X) or "ports" (Y), not "port". > > Below are OK > > > > of_graph_get_next_endpoint(node, NULL); // node/ports/port@0/endpoint > > of_graph_get_next_endpoint(ports, NULL); // node/ports/port@0/endpoint > > > > In other words, we can't handle A1/A2 directly via > > of_graph_get_next_endpoint() so far. > > > > There is another non intuitive behavior on of_graph_get_next_endpoint(). > > In case of if I could get A1 pointer for some way, and if I want to > > handle port@1 things, I would like use it like below > > > > /* > > * "endpoint" is now A1, and handle port1 things here, > > * but we don't know how many endpoints port1 has. > > * > > * Because "endpoint" is non NULL, we can use port1 > > * as of_graph_get_next_endpoint(port1, xxx) > > */ > > do { > > /* do something for port1 specific things here */ > > } while (endpoint = of_graph_get_next_endpoint(port1, endpoint)) > > > > But it also not worked as I expected. > > I expect it will be A1 -> A2 -> NULL, > > but it will be A1 -> A2 -> B, because of_graph_get_next_endpoint() > > will fetch endpoint beyond the port. > > > > It is not useful on generic driver like Generic Sound Card. > > It uses of_get_next_child() instead for now, but it is not intuitive, > > and not check node name (= "endpoint"). > > > > To handle endpoint more intuitive, create of_graph_get_next_endpoint_raw() > > > > of_graph_get_next_endpoint_raw(port1, NULL); // A1 > > of_graph_get_next_endpoint_raw(port1, A1); // A2 > > of_graph_get_next_endpoint_raw(port1, A2); // NULL > > > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > > --- > > drivers/of/property.c | 26 +++++++++++++++++++++++++- > > include/linux/of_graph.h | 2 ++ > > 2 files changed, 27 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/of/property.c b/drivers/of/property.c > > index 14ffd199c9b1..37dbb1b0e742 100644 > > --- a/drivers/of/property.c > > +++ b/drivers/of/property.c > > @@ -667,6 +667,30 @@ struct device_node *of_graph_get_next_port(const struct device_node *parent, > > } > > EXPORT_SYMBOL(of_graph_get_next_port); > > > > +/** > > + * of_graph_get_next_endpoint_raw() - get next endpoint node > > How about "of_graph_get_next_port_endpoint()"? We may want to also rename the existing of_graph_get_next_endpoint() function to of_graph_next_dev_endpoint() then. It would be a tree-wide patch, which is always annoying to get reviewed and merged, so if Rob would prefer avoiding the rename, I'm fine with that. > > + * @port: pointer to the target port node > > + * @endpoint: current endpoint node, or NULL to get first > > + * > > + * Return: An 'endpoint' node pointer with refcount incremented. Refcount > > + * of the passed @prev node is decremented. > > + */ > > It might be good to highlight here the difference to the > of_graph_get_next_endpoint(). Yes, and the documentation of of_graph_get_next_endpoint() shoul also be improved. > > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > > + struct device_node *endpoint) > > +{ > > + if (!port) > > + return NULL; > > + > > + do { > > + endpoint = of_get_next_child(port, endpoint); > > + if (!endpoint) > > + break; > > + } while (!of_node_name_eq(endpoint, "endpoint")); > > + > > + return endpoint; > > +} > > +EXPORT_SYMBOL(of_graph_get_next_endpoint_raw); > > + > > /** > > * of_graph_get_next_endpoint() - get next endpoint node > > * @parent: pointer to the parent device node > > @@ -708,7 +732,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > > * getting the next child. If the previous endpoint is NULL this > > * will return the first child. > > */ > > - endpoint = of_get_next_child(port, prev); > > + endpoint = of_graph_get_next_endpoint_raw(port, prev); > > if (endpoint) { > > of_node_put(port); > > return endpoint; > > diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h > > index fff598640e93..427905a6e8c3 100644 > > --- a/include/linux/of_graph.h > > +++ b/include/linux/of_graph.h > > @@ -57,6 +57,8 @@ int of_graph_get_port_count(const struct device_node *np); > > struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id); > > struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > > struct device_node *previous); > > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > > + struct device_node *prev); > > struct device_node *of_graph_get_next_port(const struct device_node *parent, > > struct device_node *previous); > > struct device_node *of_graph_get_endpoint_by_regs(
Hi Morimoto-san, On Mon, Jan 29, 2024 at 12:54:59AM +0000, Kuninori Morimoto wrote: > We already have of_graph_get_next_endpoint(), but it is not intuitive > to use. > > (X) node { > (Y) ports { > port@0 { endpoint { remote-endpoint = ...; };}; > (A1) port@1 { endpoint { remote-endpoint = ...; }; > (A2) endpoint { remote-endpoint = ...; };}; > (B) port@2 { endpoint { remote-endpoint = ...; };}; > }; > }; > > For example, if I want to handle port@1's 2 endpoints (= A1, A2), > I want to use like below > > A1 = of_graph_get_next_endpoint(port1, NULL); > A2 = of_graph_get_next_endpoint(port1, A1); > > But 1st one will be error, because of_graph_get_next_endpoint() requested > "parent" means "node" (X) or "ports" (Y), not "port". > Below are OK > > of_graph_get_next_endpoint(node, NULL); // node/ports/port@0/endpoint > of_graph_get_next_endpoint(ports, NULL); // node/ports/port@0/endpoint > > In other words, we can't handle A1/A2 directly via > of_graph_get_next_endpoint() so far. > > There is another non intuitive behavior on of_graph_get_next_endpoint(). > In case of if I could get A1 pointer for some way, and if I want to > handle port@1 things, I would like use it like below > > /* > * "endpoint" is now A1, and handle port1 things here, > * but we don't know how many endpoints port1 has. > * > * Because "endpoint" is non NULL, we can use port1 > * as of_graph_get_next_endpoint(port1, xxx) > */ > do { > /* do something for port1 specific things here */ > } while (endpoint = of_graph_get_next_endpoint(port1, endpoint)) > > But it also not worked as I expected. > I expect it will be A1 -> A2 -> NULL, > but it will be A1 -> A2 -> B, because of_graph_get_next_endpoint() > will fetch endpoint beyond the port. > > It is not useful on generic driver like Generic Sound Card. > It uses of_get_next_child() instead for now, but it is not intuitive, > and not check node name (= "endpoint"). > > To handle endpoint more intuitive, create of_graph_get_next_endpoint_raw() > > of_graph_get_next_endpoint_raw(port1, NULL); // A1 > of_graph_get_next_endpoint_raw(port1, A1); // A2 > of_graph_get_next_endpoint_raw(port1, A2); // NULL > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > --- > drivers/of/property.c | 26 +++++++++++++++++++++++++- > include/linux/of_graph.h | 2 ++ > 2 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/property.c b/drivers/of/property.c > index 14ffd199c9b1..37dbb1b0e742 100644 > --- a/drivers/of/property.c > +++ b/drivers/of/property.c > @@ -667,6 +667,30 @@ struct device_node *of_graph_get_next_port(const struct device_node *parent, > } > EXPORT_SYMBOL(of_graph_get_next_port); > > +/** > + * of_graph_get_next_endpoint_raw() - get next endpoint node > + * @port: pointer to the target port node > + * @endpoint: current endpoint node, or NULL to get first > + * > + * Return: An 'endpoint' node pointer with refcount incremented. Refcount > + * of the passed @prev node is decremented. > + */ > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > + struct device_node *endpoint) > +{ > + if (!port) > + return NULL; of_get_next_child() returns NULL if node is NULL, hence there's no need to check this. > + > + do { > + endpoint = of_get_next_child(port, endpoint); > + if (!endpoint) > + break; > + } while (!of_node_name_eq(endpoint, "endpoint")); > + > + return endpoint; > +} > +EXPORT_SYMBOL(of_graph_get_next_endpoint_raw); > + > /** > * of_graph_get_next_endpoint() - get next endpoint node > * @parent: pointer to the parent device node > @@ -708,7 +732,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > * getting the next child. If the previous endpoint is NULL this > * will return the first child. > */ > - endpoint = of_get_next_child(port, prev); > + endpoint = of_graph_get_next_endpoint_raw(port, prev); > if (endpoint) { > of_node_put(port); > return endpoint; > diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h > index fff598640e93..427905a6e8c3 100644 > --- a/include/linux/of_graph.h > +++ b/include/linux/of_graph.h > @@ -57,6 +57,8 @@ int of_graph_get_port_count(const struct device_node *np); > struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id); > struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > struct device_node *previous); > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > + struct device_node *prev); > struct device_node *of_graph_get_next_port(const struct device_node *parent, > struct device_node *previous); > struct device_node *of_graph_get_endpoint_by_regs(
Hi Laurent, Tomi Thank you for your review > > > +/** > > > + * of_graph_get_next_endpoint_raw() - get next endpoint node > > > > How about "of_graph_get_next_port_endpoint()"? > > We may want to also rename the existing of_graph_get_next_endpoint() > function to of_graph_next_dev_endpoint() then. It would be a tree-wide > patch, which is always annoying to get reviewed and merged, so if Rob > would prefer avoiding the rename, I'm fine with that. To be honest, from intuitive function naming point of view, I prefer rename existing function name. But yes, it will be big patch. Current of_graph_get_next_endpoint() will get next endpoint beyond the port (A) New function is not get next endpoint beyond the port (B) Something like (A) of_graph_get_next_endpoint() -> of_graph_get_next_port_endpoint() (B) of_graph_get_next_endpoint() > > > + * @port: pointer to the target port node > > > + * @endpoint: current endpoint node, or NULL to get first > > > + * > > > + * Return: An 'endpoint' node pointer with refcount incremented. Refcount > > > + * of the passed @prev node is decremented. > > > + */ > > > > It might be good to highlight here the difference to the > > of_graph_get_next_endpoint(). > > Yes, and the documentation of of_graph_get_next_endpoint() shoul also be > improved. Yes, Indeed. Thank you for your help !! Best regards --- Renesas Electronics Ph.D. Kuninori Morimoto
Hi Sakari > > +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, > > + struct device_node *endpoint) > > +{ > > + if (!port) > > + return NULL; > > of_get_next_child() returns NULL if node is NULL, hence there's no need to > check this. Thanks, will fix in v3 Thank you for your help !! Best regards --- Renesas Electronics Ph.D. Kuninori Morimoto
On Mon, Jan 29, 2024 at 03:02:19PM +0200, Laurent Pinchart wrote: > On Mon, Jan 29, 2024 at 02:29:22PM +0200, Tomi Valkeinen wrote: > > On 29/01/2024 02:54, Kuninori Morimoto wrote: > > > We already have of_graph_get_next_endpoint(), but it is not intuitive > > > to use. > > > > > > (X) node { > > > (Y) ports { > > > port@0 { endpoint { remote-endpoint = ...; };}; > > > (A1) port@1 { endpoint { remote-endpoint = ...; }; > > > (A2) endpoint { remote-endpoint = ...; };}; > > > (B) port@2 { endpoint { remote-endpoint = ...; };}; > > > }; > > > }; > > > > > > For example, if I want to handle port@1's 2 endpoints (= A1, A2), > > > I want to use like below > > > > > > A1 = of_graph_get_next_endpoint(port1, NULL); > > > A2 = of_graph_get_next_endpoint(port1, A1); > > > > > > But 1st one will be error, because of_graph_get_next_endpoint() requested > > > "parent" means "node" (X) or "ports" (Y), not "port". > > > Below are OK > > > > > > of_graph_get_next_endpoint(node, NULL); // node/ports/port@0/endpoint > > > of_graph_get_next_endpoint(ports, NULL); // node/ports/port@0/endpoint > > > > > > In other words, we can't handle A1/A2 directly via > > > of_graph_get_next_endpoint() so far. > > > > > > There is another non intuitive behavior on of_graph_get_next_endpoint(). > > > In case of if I could get A1 pointer for some way, and if I want to > > > handle port@1 things, I would like use it like below > > > > > > /* > > > * "endpoint" is now A1, and handle port1 things here, > > > * but we don't know how many endpoints port1 has. > > > * > > > * Because "endpoint" is non NULL, we can use port1 > > > * as of_graph_get_next_endpoint(port1, xxx) > > > */ > > > do { > > > /* do something for port1 specific things here */ > > > } while (endpoint = of_graph_get_next_endpoint(port1, endpoint)) > > > > > > But it also not worked as I expected. > > > I expect it will be A1 -> A2 -> NULL, > > > but it will be A1 -> A2 -> B, because of_graph_get_next_endpoint() > > > will fetch endpoint beyond the port. > > > > > > It is not useful on generic driver like Generic Sound Card. > > > It uses of_get_next_child() instead for now, but it is not intuitive, > > > and not check node name (= "endpoint"). > > > > > > To handle endpoint more intuitive, create of_graph_get_next_endpoint_raw() > > > > > > of_graph_get_next_endpoint_raw(port1, NULL); // A1 > > > of_graph_get_next_endpoint_raw(port1, A1); // A2 > > > of_graph_get_next_endpoint_raw(port1, A2); // NULL > > > > > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > > > --- > > > drivers/of/property.c | 26 +++++++++++++++++++++++++- > > > include/linux/of_graph.h | 2 ++ > > > 2 files changed, 27 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/of/property.c b/drivers/of/property.c > > > index 14ffd199c9b1..37dbb1b0e742 100644 > > > --- a/drivers/of/property.c > > > +++ b/drivers/of/property.c > > > @@ -667,6 +667,30 @@ struct device_node *of_graph_get_next_port(const struct device_node *parent, > > > } > > > EXPORT_SYMBOL(of_graph_get_next_port); > > > > > > +/** > > > + * of_graph_get_next_endpoint_raw() - get next endpoint node > > > > How about "of_graph_get_next_port_endpoint()"? > > We may want to also rename the existing of_graph_get_next_endpoint() > function to of_graph_next_dev_endpoint() then. It would be a tree-wide > patch, which is always annoying to get reviewed and merged, so if Rob > would prefer avoiding the rename, I'm fine with that. I think we should get rid of or minimize of_graph_get_next_endpoint() in its current form. In general, drivers should be asking for a specific port number because their function is fixed in the binding. Iterating over endpoints within a port is okay as that's usually a selecting 1 of N operation. Most cases are in the form of of_graph_get_next_endpoint(dev, NULL) which is equivalent to of_graph_get_endpoint_by_regs(dev, 0, 0). Technically, -1 instead of 0 is equivalent, but I'd argue is sloppy and wrong. I also added of_graph_get_remote_node() for this reason and cleaned a lot of these (in DRM) up some time ago. Because in the end, a driver generally just wants the remote device it is connected to and details of parsing the graph should be mostly opaque. Wouldn't something like this work for this case: #define for_each_port_endpoint_of_node(parent, port, child) \ for (child = of_graph_get_endpoint_by_regs(parent, port, -1); child != NULL; \ child = of_get_next_child(parent, child)) Rob
Hi Rob > I think we should get rid of or minimize of_graph_get_next_endpoint() in > its current form. In general, drivers should be asking for a specific > port number because their function is fixed in the binding. Iterating > over endpoints within a port is okay as that's usually a selecting 1 of > N operation. > > Most cases are in the form of of_graph_get_next_endpoint(dev, NULL) > which is equivalent to of_graph_get_endpoint_by_regs(dev, 0, 0). > Technically, -1 instead of 0 is equivalent, but I'd argue is sloppy and > wrong. > > I also added of_graph_get_remote_node() for this reason and cleaned a > lot of these (in DRM) up some time ago. Because in the end, a driver > generally just wants the remote device it is connected to and details of > parsing the graph should be mostly opaque. > > Wouldn't something like this work for this case: > > #define for_each_port_endpoint_of_node(parent, port, child) \ > for (child = of_graph_get_endpoint_by_regs(parent, port, -1); child != NULL; \ > child = of_get_next_child(parent, child)) I see. I will split this patch-set to like below - patch-set for reduce/remove to using current next_endpoint() - patch-set for rename current next_endpoint() to next_device_endpoint() - patch-set for adding new next_port_endpoint() Thank you for your help !! Best regards --- Renesas Electronics Ph.D. Kuninori Morimoto
Hi Rob > > #define for_each_port_endpoint_of_node(parent, port, child) \ > > for (child = of_graph_get_endpoint_by_regs(parent, port, -1); child != NULL; \ > > child = of_get_next_child(parent, child)) Hmm... I noticed it is impossible so for. of_graph_get_endpoint_by_regs() (A) is based on for_each_endpoint_of_node() (B). Thus, we can't replace for_each_endpoint_of_node() (B) with by_regs (A) (A) struct device_node *of_graph_get_endpoint_by_regs(...) { ... (B) for_each_endpoint_of_node(parent, node) { ... } return NULL; } > - patch-set for reduce/remove to using current next_endpoint() > - patch-set for rename current next_endpoint() to next_device_endpoint() > - patch-set for adding new next_port_endpoint() So, maybe we can do is, 0) rename current endpoint functions to device_endpoint 1) add new port base functions (port_endpoint) which has for_each_of_graph_port_endpoint() loop. It is for port base endpoint loop (I want to use new naming, using of_graph instead of _of_node). 2) replace above (B) part with port base loops - for_each_endpoint_of_node(parent, node) { + for_each_of_gprah_port(parent, port) { + for_each_of_graph_port_endpoint(port, endpoint) { 3) replace current next_endpoint() by next_endpoint_by_regs(), and remove next_endpoint() What do you think ? Thank you for your help !! Best regards --- Renesas Electronics Ph.D. Kuninori Morimoto
diff --git a/drivers/of/property.c b/drivers/of/property.c index 14ffd199c9b1..37dbb1b0e742 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -667,6 +667,30 @@ struct device_node *of_graph_get_next_port(const struct device_node *parent, } EXPORT_SYMBOL(of_graph_get_next_port); +/** + * of_graph_get_next_endpoint_raw() - get next endpoint node + * @port: pointer to the target port node + * @endpoint: current endpoint node, or NULL to get first + * + * Return: An 'endpoint' node pointer with refcount incremented. Refcount + * of the passed @prev node is decremented. + */ +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, + struct device_node *endpoint) +{ + if (!port) + return NULL; + + do { + endpoint = of_get_next_child(port, endpoint); + if (!endpoint) + break; + } while (!of_node_name_eq(endpoint, "endpoint")); + + return endpoint; +} +EXPORT_SYMBOL(of_graph_get_next_endpoint_raw); + /** * of_graph_get_next_endpoint() - get next endpoint node * @parent: pointer to the parent device node @@ -708,7 +732,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, * getting the next child. If the previous endpoint is NULL this * will return the first child. */ - endpoint = of_get_next_child(port, prev); + endpoint = of_graph_get_next_endpoint_raw(port, prev); if (endpoint) { of_node_put(port); return endpoint; diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h index fff598640e93..427905a6e8c3 100644 --- a/include/linux/of_graph.h +++ b/include/linux/of_graph.h @@ -57,6 +57,8 @@ int of_graph_get_port_count(const struct device_node *np); struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id); struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, struct device_node *previous); +struct device_node *of_graph_get_next_endpoint_raw(const struct device_node *port, + struct device_node *prev); struct device_node *of_graph_get_next_port(const struct device_node *parent, struct device_node *previous); struct device_node *of_graph_get_endpoint_by_regs(
We already have of_graph_get_next_endpoint(), but it is not intuitive to use. (X) node { (Y) ports { port@0 { endpoint { remote-endpoint = ...; };}; (A1) port@1 { endpoint { remote-endpoint = ...; }; (A2) endpoint { remote-endpoint = ...; };}; (B) port@2 { endpoint { remote-endpoint = ...; };}; }; }; For example, if I want to handle port@1's 2 endpoints (= A1, A2), I want to use like below A1 = of_graph_get_next_endpoint(port1, NULL); A2 = of_graph_get_next_endpoint(port1, A1); But 1st one will be error, because of_graph_get_next_endpoint() requested "parent" means "node" (X) or "ports" (Y), not "port". Below are OK of_graph_get_next_endpoint(node, NULL); // node/ports/port@0/endpoint of_graph_get_next_endpoint(ports, NULL); // node/ports/port@0/endpoint In other words, we can't handle A1/A2 directly via of_graph_get_next_endpoint() so far. There is another non intuitive behavior on of_graph_get_next_endpoint(). In case of if I could get A1 pointer for some way, and if I want to handle port@1 things, I would like use it like below /* * "endpoint" is now A1, and handle port1 things here, * but we don't know how many endpoints port1 has. * * Because "endpoint" is non NULL, we can use port1 * as of_graph_get_next_endpoint(port1, xxx) */ do { /* do something for port1 specific things here */ } while (endpoint = of_graph_get_next_endpoint(port1, endpoint)) But it also not worked as I expected. I expect it will be A1 -> A2 -> NULL, but it will be A1 -> A2 -> B, because of_graph_get_next_endpoint() will fetch endpoint beyond the port. It is not useful on generic driver like Generic Sound Card. It uses of_get_next_child() instead for now, but it is not intuitive, and not check node name (= "endpoint"). To handle endpoint more intuitive, create of_graph_get_next_endpoint_raw() of_graph_get_next_endpoint_raw(port1, NULL); // A1 of_graph_get_next_endpoint_raw(port1, A1); // A2 of_graph_get_next_endpoint_raw(port1, A2); // NULL Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> --- drivers/of/property.c | 26 +++++++++++++++++++++++++- include/linux/of_graph.h | 2 ++ 2 files changed, 27 insertions(+), 1 deletion(-)