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path: root/drivers/acpi/property.c
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Diffstat (limited to 'drivers/acpi/property.c')
-rw-r--r--drivers/acpi/property.c117
1 files changed, 68 insertions, 49 deletions
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index f2fd3fee588a..03f5ec11ab31 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -468,10 +468,11 @@ static int acpi_data_get_property_array(struct acpi_device_data *data,
}
/**
- * acpi_data_get_property_reference - returns handle to the referenced object
- * @data: ACPI device data object containing the property
+ * __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
*
* Find property with @name, verifify that it is a package containing at least
@@ -482,17 +483,40 @@ static int acpi_data_get_property_array(struct acpi_device_data *data,
* 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 return %-ENOENT and with index %3
+ * returns the last entry. If the property does not contain any more values
+ * %-ENODATA is returned. The NULL entry must be single integer and
+ * preferably contain value %0.
+ *
* Return: %0 on success, negative error code on failure.
*/
-static int acpi_data_get_property_reference(struct acpi_device_data *data,
- const char *propname, size_t index,
- struct acpi_reference_args *args)
+int __acpi_node_get_property_reference(struct fwnode_handle *fwnode,
+ const char *propname, size_t index, size_t num_args,
+ struct acpi_reference_args *args)
{
const union acpi_object *element, *end;
const union acpi_object *obj;
+ struct acpi_device_data *data;
struct acpi_device *device;
int ret, idx = 0;
+ data = acpi_device_data_of_node(fwnode);
+ if (!data)
+ return -EINVAL;
+
ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);
if (ret)
return ret;
@@ -532,59 +556,54 @@ static int acpi_data_get_property_reference(struct acpi_device_data *data,
while (element < end) {
u32 nargs, i;
- if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
- return -EPROTO;
-
- ret = acpi_bus_get_device(element->reference.handle, &device);
- if (ret)
- return -ENODEV;
-
- element++;
- nargs = 0;
-
- /* assume following integer elements are all args */
- for (i = 0; element + i < end; i++) {
- int type = element[i].type;
+ if (element->type == ACPI_TYPE_LOCAL_REFERENCE) {
+ ret = acpi_bus_get_device(element->reference.handle,
+ &device);
+ if (ret)
+ return -ENODEV;
+
+ nargs = 0;
+ element++;
+
+ /* assume following integer elements are all args */
+ for (i = 0; element + i < end && i < num_args; i++) {
+ int type = element[i].type;
+
+ if (type == ACPI_TYPE_INTEGER)
+ nargs++;
+ else if (type == ACPI_TYPE_LOCAL_REFERENCE)
+ break;
+ else
+ return -EPROTO;
+ }
- if (type == ACPI_TYPE_INTEGER)
- nargs++;
- else if (type == ACPI_TYPE_LOCAL_REFERENCE)
- break;
- else
+ if (nargs > MAX_ACPI_REFERENCE_ARGS)
return -EPROTO;
- }
- if (idx++ == index) {
- args->adev = device;
- args->nargs = nargs;
- for (i = 0; i < nargs; i++)
- args->args[i] = element[i].integer.value;
+ if (idx == index) {
+ args->adev = device;
+ args->nargs = nargs;
+ for (i = 0; i < nargs; i++)
+ args->args[i] = element[i].integer.value;
- return 0;
+ return 0;
+ }
+
+ element += nargs;
+ } else if (element->type == ACPI_TYPE_INTEGER) {
+ if (idx == index)
+ return -ENOENT;
+ element++;
+ } else {
+ return -EPROTO;
}
- element += nargs;
+ idx++;
}
- return -EPROTO;
-}
-
-/**
- * acpi_node_get_property_reference - get a 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.
- * @args: Location to store the returned reference with optional arguments.
- */
-int acpi_node_get_property_reference(struct fwnode_handle *fwnode,
- const char *name, size_t index,
- struct acpi_reference_args *args)
-{
- struct acpi_device_data *data = acpi_device_data_of_node(fwnode);
-
- return data ? acpi_data_get_property_reference(data, name, index, args) : -EINVAL;
+ return -ENODATA;
}
-EXPORT_SYMBOL_GPL(acpi_node_get_property_reference);
+EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);
static int acpi_data_prop_read_single(struct acpi_device_data *data,
const char *propname,