[PATCH v3 15/23] ACPI: property: Add support for cells property

Anup Patel
2025-05-11T13:42:13Z

From: Sunil V L <sunilvl@ventanamicro.com>

Currently, ACPI doesn't support cells property when
fwnode_property_get_reference_args() is called. ACPI always expects the
number of arguments to be passed. However,
fwnode_property_get_reference_args() being a common interface for OF and
ACPI, it is better to have single calling convention which works for
both. Hence, add support for cells property on the reference device to
get the number of arguments dynamically.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
drivers/acpi/property.c | 15 +++++++++++++++
drivers/base/property.c | 2 +-
2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 364c58faf13f..51352bde617a 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -960,6 +960,13 @@ static int acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
if (!device)
return -EINVAL;

+ if (nargs_prop) {
+ if (!acpi_dev_get_property(device, nargs_prop,
+ ACPI_TYPE_INTEGER, &obj)) {
+ args_count = obj->integer.value;
+ }
+ }
+
element++;

ret = acpi_get_ref_args(idx == index ? args : NULL,
@@ -978,6 +985,14 @@ static int acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
if (!ref_fwnode)
return -EINVAL;

+ if (nargs_prop) {
+ device = to_acpi_device_node(ref_fwnode);
+ if (!acpi_dev_get_property(device, nargs_prop,
+ ACPI_TYPE_INTEGER, &obj)) {
+ args_count = obj->integer.value;
+ }
+ }
+
element++;

ret = acpi_get_ref_args(idx == index ? args : NULL,
diff --git a/drivers/base/property.c b/drivers/base/property.c
index c1392743df9c..172dfb950328 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -578,7 +578,7 @@ EXPORT_SYMBOL_GPL(fwnode_property_match_property_string);
* @prop: The name of the property
* @nargs_prop: The name of the property telling the number of
* arguments in the referred node. NULL if @nargs is known,
- * otherwise @nargs is ignored. Only relevant on OF.
+ * otherwise @nargs is ignored.
* @nargs: Number of arguments. Ignored if @nargs_prop is non-NULL.
* @index: Index of the reference, from zero onwards.
* @args: Result structure with reference and integer arguments.
--
2.43.0