From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
At the moment software nodes can only reference other software nodes.
This is a limitation for devices created, for instance, on the auxiliary
bus with a dynamic software node attached which cannot reference devices
the firmware node of which is "real" (as an OF node or otherwise).
Make it possible for a software node to reference all firmware nodes in
addition to static software nodes. To that end: use a union of different
pointers in struct software_node_ref_args and add an enum indicating
what kind of reference given instance of it is. Rework the helper macros
and deprecate the existing ones whose names don't indicate the reference
type.
Software node graphs remain the same, as in: the remote endpoints still
have to be software nodes.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
drivers/base/swnode.c | 14 ++++++++++----
include/linux/property.h | 40 +++++++++++++++++++++++++++++++++-------
2 files changed, 43 insertions(+), 11 deletions(-)
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index b7c3926b67be72671ba4e4c442b3acca80688cf7..d08b914c07691336540cdf1dfbd77a697e7b4521 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -535,9 +535,12 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
ref_array = prop->pointer;
ref = &ref_array[index];
- refnode = software_node_fwnode(ref->node);
- if (!refnode)
- return -ENOENT;
+ if (ref->swnode)
+ refnode = software_node_fwnode(ref->swnode);
+ else if (ref->fwnode)
+ refnode = ref->fwnode;
+ else
+ return -EINVAL;
if (nargs_prop) {
error = fwnode_property_read_u32(refnode, nargs_prop,
@@ -634,7 +637,10 @@ software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
ref = prop->pointer;
- return software_node_get(software_node_fwnode(ref[0].node));
+ if (!ref->swnode)
+ return NULL;
+
+ return software_node_get(software_node_fwnode(ref[0].swnode));
}
static struct fwnode_handle *
diff --git a/include/linux/property.h b/include/linux/property.h
index 50b26589dd70d1756f3b8644255c24a011e2617c..52e784a3dfd4c93cee8b35e1cef5e0600639ecc5 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -355,23 +355,37 @@ struct software_node;
/**
* struct software_node_ref_args - Reference property with additional arguments
- * @node: Reference to a software node
+ * @swnode: Reference to a software node
+ * @fwnode: Alternative reference to a firmware node handle
* @nargs: Number of elements in @args array
* @args: Integer arguments
*/
struct software_node_ref_args {
- const struct software_node *node;
+ const struct software_node *swnode;
+ struct fwnode_handle *fwnode;
unsigned int nargs;
u64 args[NR_FWNODE_REFERENCE_ARGS];
};
-#define SOFTWARE_NODE_REFERENCE(_ref_, ...) \
+#define __SOFTWARE_NODE_REF(_ref, _type, _node, ...) \
(const struct software_node_ref_args) { \
- .node = _ref_, \
+ ._node = _ref, \
.nargs = COUNT_ARGS(__VA_ARGS__), \
.args = { __VA_ARGS__ }, \
}
+#define SOFTWARE_NODE_REF_SWNODE(_ref, ...) \
+ __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_SWNODE, \
+ swnode, __VA_ARGS__)
+
+#define SOFTWARE_NODE_REF_FWNODE(_ref, ...) \
+ __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_FWNODE, \
+ fwnode, __VA_ARGS__)
+
+/* DEPRECATED, use SOFTWARE_NODE_REF_SWNODE() instead. */
+#define SOFTWARE_NODE_REFERENCE(_ref, ...) \
+ SOFTWARE_NODE_REF_SWNODE(_ref, __VA_ARGS__)
+
/**
* struct property_entry - "Built-in" device property representation.
* @name: Name of the property.
@@ -463,14 +477,26 @@ struct property_entry {
#define PROPERTY_ENTRY_STRING(_name_, _val_) \
__PROPERTY_ENTRY_ELEMENT(_name_, str, STRING, _val_)
-#define PROPERTY_ENTRY_REF(_name_, _ref_, ...) \
+#define __PROPERTY_ENTRY_REF(_type, _name, _ref, ...) \
(struct property_entry) { \
- .name = _name_, \
+ .name = _name, \
.length = sizeof(struct software_node_ref_args), \
.type = DEV_PROP_REF, \
- { .pointer = &SOFTWARE_NODE_REFERENCE(_ref_, ##__VA_ARGS__), }, \
+ { .pointer = &_type(_ref, ##__VA_ARGS__), }, \
}
+#define PROPERTY_ENTRY_REF_SWNODE(_name, _ref, ...) \
+ __PROPERTY_ENTRY_REF(SOFTWARE_NODE_REF_SWNODE, \
+ _name, _ref, __VA_ARGS__)
+
+#define PROPERTY_ENTRY_REF_FWNODE(_name, _ref, ...) \
+ __PROPERTY_ENTRY_REF(SOFTWARE_NODE_REF_FWNODE, \
+ _name, _ref, __VA_ARGS__)
+
+/* DEPRECATED, use PROPERTY_ENTRY_REF_SWNODE() instead. */
+#define PROPERTY_ENTRY_REF(_name, _ref, ...) \
+ PROPERTY_ENTRY_REF_SWNODE(_name, _ref, __VA_ARGS__)
+
#define PROPERTY_ENTRY_BOOL(_name_) \
(struct property_entry) { \
.name = _name_, \
--
2.48.1Hi Bartosz,
On Wed, Oct 22, 2025 at 03:41:02PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> At the moment software nodes can only reference other software nodes.
> This is a limitation for devices created, for instance, on the auxiliary
> bus with a dynamic software node attached which cannot reference devices
> the firmware node of which is "real" (as an OF node or otherwise).
That's not entirely true: you can add a software node as a secondary to an
existing OF or ACPI fwnode. This has not been used widely and it's not very
convenient to set up.
Additional properties in ACPI or OF nodes will still need the secondary
node, after these patches.
>
> Make it possible for a software node to reference all firmware nodes in
> addition to static software nodes. To that end: use a union of different
> pointers in struct software_node_ref_args and add an enum indicating
> what kind of reference given instance of it is. Rework the helper macros
> and deprecate the existing ones whose names don't indicate the reference
> type.
>
> Software node graphs remain the same, as in: the remote endpoints still
> have to be software nodes.
>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> ---
> drivers/base/swnode.c | 14 ++++++++++----
> include/linux/property.h | 40 +++++++++++++++++++++++++++++++++-------
> 2 files changed, 43 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index b7c3926b67be72671ba4e4c442b3acca80688cf7..d08b914c07691336540cdf1dfbd77a697e7b4521 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -535,9 +535,12 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
> ref_array = prop->pointer;
> ref = &ref_array[index];
>
> - refnode = software_node_fwnode(ref->node);
> - if (!refnode)
> - return -ENOENT;
> + if (ref->swnode)
> + refnode = software_node_fwnode(ref->swnode);
> + else if (ref->fwnode)
> + refnode = ref->fwnode;
> + else
> + return -EINVAL;
>
> if (nargs_prop) {
> error = fwnode_property_read_u32(refnode, nargs_prop,
> @@ -634,7 +637,10 @@ software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
>
> ref = prop->pointer;
>
> - return software_node_get(software_node_fwnode(ref[0].node));
> + if (!ref->swnode)
> + return NULL;
> +
> + return software_node_get(software_node_fwnode(ref[0].swnode));
> }
>
> static struct fwnode_handle *
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 50b26589dd70d1756f3b8644255c24a011e2617c..52e784a3dfd4c93cee8b35e1cef5e0600639ecc5 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -355,23 +355,37 @@ struct software_node;
>
> /**
> * struct software_node_ref_args - Reference property with additional arguments
> - * @node: Reference to a software node
> + * @swnode: Reference to a software node
> + * @fwnode: Alternative reference to a firmware node handle
> * @nargs: Number of elements in @args array
> * @args: Integer arguments
> */
> struct software_node_ref_args {
> - const struct software_node *node;
> + const struct software_node *swnode;
> + struct fwnode_handle *fwnode;
> unsigned int nargs;
> u64 args[NR_FWNODE_REFERENCE_ARGS];
> };
>
> -#define SOFTWARE_NODE_REFERENCE(_ref_, ...) \
> +#define __SOFTWARE_NODE_REF(_ref, _type, _node, ...) \
> (const struct software_node_ref_args) { \
> - .node = _ref_, \
> + ._node = _ref, \
> .nargs = COUNT_ARGS(__VA_ARGS__), \
> .args = { __VA_ARGS__ }, \
> }
>
> +#define SOFTWARE_NODE_REF_SWNODE(_ref, ...) \
> + __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_SWNODE, \
> + swnode, __VA_ARGS__)
> +
> +#define SOFTWARE_NODE_REF_FWNODE(_ref, ...) \
> + __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_FWNODE, \
> + fwnode, __VA_ARGS__)
> +
> +/* DEPRECATED, use SOFTWARE_NODE_REF_SWNODE() instead. */
> +#define SOFTWARE_NODE_REFERENCE(_ref, ...) \
> + SOFTWARE_NODE_REF_SWNODE(_ref, __VA_ARGS__)
> +
> /**
> * struct property_entry - "Built-in" device property representation.
> * @name: Name of the property.
> @@ -463,14 +477,26 @@ struct property_entry {
> #define PROPERTY_ENTRY_STRING(_name_, _val_) \
> __PROPERTY_ENTRY_ELEMENT(_name_, str, STRING, _val_)
>
> -#define PROPERTY_ENTRY_REF(_name_, _ref_, ...) \
> +#define __PROPERTY_ENTRY_REF(_type, _name, _ref, ...) \
> (struct property_entry) { \
> - .name = _name_, \
> + .name = _name, \
> .length = sizeof(struct software_node_ref_args), \
> .type = DEV_PROP_REF, \
> - { .pointer = &SOFTWARE_NODE_REFERENCE(_ref_, ##__VA_ARGS__), }, \
> + { .pointer = &_type(_ref, ##__VA_ARGS__), }, \
> }
>
> +#define PROPERTY_ENTRY_REF_SWNODE(_name, _ref, ...) \
> + __PROPERTY_ENTRY_REF(SOFTWARE_NODE_REF_SWNODE, \
> + _name, _ref, __VA_ARGS__)
> +
> +#define PROPERTY_ENTRY_REF_FWNODE(_name, _ref, ...) \
> + __PROPERTY_ENTRY_REF(SOFTWARE_NODE_REF_FWNODE, \
> + _name, _ref, __VA_ARGS__)
> +
> +/* DEPRECATED, use PROPERTY_ENTRY_REF_SWNODE() instead. */
> +#define PROPERTY_ENTRY_REF(_name, _ref, ...) \
> + PROPERTY_ENTRY_REF_SWNODE(_name, _ref, __VA_ARGS__)
> +
> #define PROPERTY_ENTRY_BOOL(_name_) \
> (struct property_entry) { \
> .name = _name_, \
>
--
Regards,
Sakari Ailus
On Fri, Oct 24, 2025 at 5:17 PM Sakari Ailus <sakari.ailus@linux.intel.com> wrote: > > Hi Bartosz, > > On Wed, Oct 22, 2025 at 03:41:02PM +0200, Bartosz Golaszewski wrote: > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > > > At the moment software nodes can only reference other software nodes. > > This is a limitation for devices created, for instance, on the auxiliary > > bus with a dynamic software node attached which cannot reference devices > > the firmware node of which is "real" (as an OF node or otherwise). > > That's not entirely true: you can add a software node as a secondary to an > existing OF or ACPI fwnode. This has not been used widely and it's not very > convenient to set up. First: set_secondary_fwnode() API seems to require a struct device, what if we don't have one yet? Unless you're talking about a different interface. Second: are we even allowed to modify an existing fwnode from a random place in the kernel? I mean: I'm module X and there's an fwnode Y, I don't know what it is. Can I just arbitrarily add a secondary node to it? > > Additional properties in ACPI or OF nodes will still need the secondary > node, after these patches. > That's not the goal of this series. Being able to create software nodes that reference real devices. In this particular case: a software node for the reset-gpio device that will allow it to resolve the reference to the physical GPIO provider. Bart
On Wed, Oct 22, 2025 at 03:41:02PM +0200, Bartosz Golaszewski wrote:
>
> At the moment software nodes can only reference other software nodes.
> This is a limitation for devices created, for instance, on the auxiliary
> bus with a dynamic software node attached which cannot reference devices
> the firmware node of which is "real" (as an OF node or otherwise).
>
> Make it possible for a software node to reference all firmware nodes in
> addition to static software nodes. To that end: use a union of different
Still union?
> pointers in struct software_node_ref_args and add an enum indicating
> what kind of reference given instance of it is. Rework the helper macros
> and deprecate the existing ones whose names don't indicate the reference
> type.
> Software node graphs remain the same, as in: the remote endpoints still
> have to be software nodes.
...
> - refnode = software_node_fwnode(ref->node);
> - if (!refnode)
> - return -ENOENT;
Why is this being dropped?
> + if (ref->swnode)
> + refnode = software_node_fwnode(ref->swnode);
> + else if (ref->fwnode)
> + refnode = ref->fwnode;
> + else
> + return -EINVAL;
>
...
> -#define SOFTWARE_NODE_REFERENCE(_ref_, ...) \
> +#define __SOFTWARE_NODE_REF(_ref, _type, _node, ...) \
> (const struct software_node_ref_args) { \
> - .node = _ref_, \
> + ._node = _ref, \
> .nargs = COUNT_ARGS(__VA_ARGS__), \
> .args = { __VA_ARGS__ }, \
> }
>
> +#define SOFTWARE_NODE_REF_SWNODE(_ref, ...) \
> + __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_SWNODE, \
> + swnode, __VA_ARGS__)
> +
> +#define SOFTWARE_NODE_REF_FWNODE(_ref, ...) \
> + __SOFTWARE_NODE_REF(_ref, SOFTWARE_NODE_REF_FWNODE, \
> + fwnode, __VA_ARGS__)
I do not see a point of making these three instead of two direct ones.
But I have no strong objection either.
--
With Best Regards,
Andy Shevchenko
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