Commit e121be78 authored by Sunil V L's avatar Sunil V L Committed by Paul Walmsley
Browse files

ACPI: property: Refactor acpi_fwnode_get_reference_args() to support nargs_prop 



Currently, acpi_fwnode_get_reference_args() delegates to the internal
function __acpi_node_get_property_reference() to retrieve property
references. However, this function does not handle the nargs_prop (cells
property) parameter, and instead expects the number of arguments (nargs)
to be known or hardcoded.

As a result, when fwnode_property_get_reference_args() is used with a
valid nargs_prop, the ACPI backend ignores it, whereas the Device Tree
(DT) backend uses the #*-cells property from the reference node to
determine the number of arguments dynamically.

To support the nargs_prop in ACPI, refactor the code as follows:

- Move the implementation from __acpi_node_get_property_reference()
  into acpi_fwnode_get_reference_args().

- Update __acpi_node_get_property_reference() to call the (now updated)
  acpi_fwnode_get_reference_args() passing NULL as nargs_prop to keep
  the behavior of __acpi_node_get_property_reference() intact.

Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Suggested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarSunil V L <sunilvl@ventanamicro.com>
Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Acked-by: default avatarJassi Brar <jassisinghbrar@gmail.com>
Link: https://lore.kernel.org/r/20250818040920.272664-15-apatel@ventanamicro.com


Signed-off-by: default avatarPaul Walmsley <pjw@kernel.org>
parent aa43953e

drivers/acpi/property.c

+50 −51
Original line number Diff line number Diff line
@@ -882,44 +882,9 @@ static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *f 
	return &dn->fwnode;

}



/**

 * __acpi_node_get_property_reference - returns handle to the referenced object

 * @fwnode: Firmware node to get the property from

 * @propname: Name of the property

 * @index: Index of the reference to return

 * @num_args: Maximum number of arguments after each reference

 * @args: Location to store the returned reference with optional arguments

 *	  (may be NULL)

 *

 * Find property with @name, verifify that it is a package containing at least

 * one object reference and if so, store the ACPI device object pointer to the

 * target object in @args->adev.  If the reference includes arguments, store

 * them in the @args->args[] array.

 *

 * If there's more than one reference in the property value package, @index is

 * used to select the one to return.

 *

 * It is possible to leave holes in the property value set like in the

 * example below:

 *

 * Package () {

 *     "cs-gpios",

 *     Package () {

 *        ^GPIO, 19, 0, 0,

 *        ^GPIO, 20, 0, 0,

 *        0,

 *        ^GPIO, 21, 0, 0,

 *     }

 * }

 *

 * Calling this function with index %2 or index %3 return %-ENOENT. If the

 * property does not contain any more values %-ENOENT is returned. The NULL

 * entry must be single integer and preferably contain value %0.

 *

 * Return: %0 on success, negative error code on failure.

 */

int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,

	const char *propname, size_t index, size_t num_args,

static int acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,

					  const char *propname, const char *nargs_prop,

					  unsigned int args_count, unsigned int index,

					  struct fwnode_reference_args *args)

{

	const union acpi_object *element, *end;
@@ -999,7 +964,7 @@ int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode, 


			ret = acpi_get_ref_args(idx == index ? args : NULL,

						acpi_fwnode_handle(device),

						&element, end, num_args);

						&element, end, args_count);

			if (ret < 0)

				return ret;
@@ -1017,7 +982,7 @@ int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode, 


			ret = acpi_get_ref_args(idx == index ? args : NULL,

						ref_fwnode, &element, end,

						num_args);

						args_count);

			if (ret < 0)

				return ret;
@@ -1039,6 +1004,50 @@ int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode, 


	return -ENOENT;

}



/**

 * __acpi_node_get_property_reference - returns handle to the referenced object

 * @fwnode: Firmware node to get the property from

 * @propname: Name of the property

 * @index: Index of the reference to return

 * @num_args: Maximum number of arguments after each reference

 * @args: Location to store the returned reference with optional arguments

 *	  (may be NULL)

 *

 * Find property with @name, verifify that it is a package containing at least

 * one object reference and if so, store the ACPI device object pointer to the

 * target object in @args->adev.  If the reference includes arguments, store

 * them in the @args->args[] array.

 *

 * If there's more than one reference in the property value package, @index is

 * used to select the one to return.

 *

 * It is possible to leave holes in the property value set like in the

 * example below:

 *

 * Package () {

 *     "cs-gpios",

 *     Package () {

 *        ^GPIO, 19, 0, 0,

 *        ^GPIO, 20, 0, 0,

 *        0,

 *        ^GPIO, 21, 0, 0,

 *     }

 * }

 *

 * Calling this function with index %2 or index %3 return %-ENOENT. If the

 * property does not contain any more values %-ENOENT is returned. The NULL

 * entry must be single integer and preferably contain value %0.

 *

 * Return: %0 on success, negative error code on failure.

 */

int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,

				       const char *propname, size_t index,

				       size_t num_args,

				       struct fwnode_reference_args *args)

{

	return acpi_fwnode_get_reference_args(fwnode, propname, NULL, index, num_args, args);

}

EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);



static int acpi_data_prop_read_single(const struct acpi_device_data *data,
@@ -1558,16 +1567,6 @@ acpi_fwnode_property_read_string_array(const struct fwnode_handle *fwnode, 
				   val, nval);

}



static int

acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,

			       const char *prop, const char *nargs_prop,

			       unsigned int args_count, unsigned int index,

			       struct fwnode_reference_args *args)

{

	return __acpi_node_get_property_reference(fwnode, prop, index,

						  args_count, args);

}



static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)

{

	const struct acpi_device *adev;