--- /dev/null
+/*
+ * ACPI device specific properties support.
+ *
+ * Copyright (C) 2014, Intel Corporation
+ * All rights reserved.
+ *
+ * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
+ * Darren Hart <dvhart@linux.intel.com>
+ * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/export.h>
+
+#include "internal.h"
+
+/* ACPI _DSD device properties UUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
+static const u8 prp_uuid[16] = {
+ 0x14, 0xd8, 0xff, 0xda, 0xba, 0x6e, 0x8c, 0x4d,
+ 0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01
+};
+
+static bool acpi_property_value_ok(const union acpi_object *value)
+{
+ int j;
+
+ /*
+ * The value must be an integer, a string, a reference, or a package
+ * whose every element must be an integer, a string, or a reference.
+ */
+ switch (value->type) {
+ case ACPI_TYPE_INTEGER:
+ case ACPI_TYPE_STRING:
+ case ACPI_TYPE_LOCAL_REFERENCE:
+ return true;
+
+ case ACPI_TYPE_PACKAGE:
+ for (j = 0; j < value->package.count; j++)
+ switch (value->package.elements[j].type) {
+ case ACPI_TYPE_INTEGER:
+ case ACPI_TYPE_STRING:
+ case ACPI_TYPE_LOCAL_REFERENCE:
+ continue;
+
+ default:
+ return false;
+ }
+
+ return true;
+ }
+ return false;
+}
+
+static bool acpi_properties_format_valid(const union acpi_object *properties)
+{
+ int i;
+
+ for (i = 0; i < properties->package.count; i++) {
+ const union acpi_object *property;
+
+ property = &properties->package.elements[i];
+ /*
+ * Only two elements allowed, the first one must be a string and
+ * the second one has to satisfy certain conditions.
+ */
+ if (property->package.count != 2
+ || property->package.elements[0].type != ACPI_TYPE_STRING
+ || !acpi_property_value_ok(&property->package.elements[1]))
+ return false;
+ }
+ return true;
+}
+
+void acpi_init_properties(struct acpi_device *adev)
+{
+ struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+ const union acpi_object *desc;
+ acpi_status status;
+ int i;
+
+ status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
+ ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status))
+ return;
+
+ desc = buf.pointer;
+ if (desc->package.count % 2)
+ goto fail;
+
+ /* Look for the device properties UUID. */
+ for (i = 0; i < desc->package.count; i += 2) {
+ const union acpi_object *uuid, *properties;
+
+ uuid = &desc->package.elements[i];
+ properties = &desc->package.elements[i + 1];
+
+ /*
+ * The first element must be a UUID and the second one must be
+ * a package.
+ */
+ if (uuid->type != ACPI_TYPE_BUFFER || uuid->buffer.length != 16
+ || properties->type != ACPI_TYPE_PACKAGE)
+ break;
+
+ if (memcmp(uuid->buffer.pointer, prp_uuid, sizeof(prp_uuid)))
+ continue;
+
+ /*
+ * We found the matching UUID. Now validate the format of the
+ * package immediately following it.
+ */
+ if (!acpi_properties_format_valid(properties))
+ break;
+
+ adev->data.pointer = buf.pointer;
+ adev->data.properties = properties;
+ return;
+ }
+
+ fail:
+ dev_warn(&adev->dev, "Returned _DSD data is not valid, skipping\n");
+ ACPI_FREE(buf.pointer);
+}
+
+void acpi_free_properties(struct acpi_device *adev)
+{
+ ACPI_FREE((void *)adev->data.pointer);
+ adev->data.pointer = NULL;
+ adev->data.properties = NULL;
+}
+
+/**
+ * acpi_dev_get_property - return an ACPI property with given name
+ * @adev: ACPI device to get property
+ * @name: Name of the property
+ * @type: Expected property type
+ * @obj: Location to store the property value (if not %NULL)
+ *
+ * Look up a property with @name and store a pointer to the resulting ACPI
+ * object at the location pointed to by @obj if found.
+ *
+ * Callers must not attempt to free the returned objects. These objects will be
+ * freed by the ACPI core automatically during the removal of @adev.
+ *
+ * Return: %0 if property with @name has been found (success),
+ * %-EINVAL if the arguments are invalid,
+ * %-ENODATA if the property doesn't exist,
+ * %-EPROTO if the property value type doesn't match @type.
+ */
+int acpi_dev_get_property(struct acpi_device *adev, const char *name,
+ acpi_object_type type, const union acpi_object **obj)
+{
+ const union acpi_object *properties;
+ int i;
+
+ if (!adev || !name)
+ return -EINVAL;
+
+ if (!adev->data.pointer || !adev->data.properties)
+ return -ENODATA;
+
+ properties = adev->data.properties;
+ for (i = 0; i < properties->package.count; i++) {
+ const union acpi_object *propname, *propvalue;
+ const union acpi_object *property;
+
+ property = &properties->package.elements[i];
+
+ propname = &property->package.elements[0];
+ propvalue = &property->package.elements[1];
+
+ if (!strcmp(name, propname->string.pointer)) {
+ if (type != ACPI_TYPE_ANY && propvalue->type != type)
+ return -EPROTO;
+ else if (obj)
+ *obj = propvalue;
+
+ return 0;
+ }
+ }
+ return -ENODATA;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_get_property);
+
+/**
+ * acpi_dev_get_property_array - return an ACPI array property with given name
+ * @adev: ACPI device to get property
+ * @name: Name of the property
+ * @type: Expected type of array elements
+ * @obj: Location to store a pointer to the property value (if not NULL)
+ *
+ * Look up an array property with @name and store a pointer to the resulting
+ * ACPI object at the location pointed to by @obj if found.
+ *
+ * Callers must not attempt to free the returned objects. Those objects will be
+ * freed by the ACPI core automatically during the removal of @adev.
+ *
+ * Return: %0 if array property (package) with @name has been found (success),
+ * %-EINVAL if the arguments are invalid,
+ * %-ENODATA if the property doesn't exist,
+ * %-EPROTO if the property is not a package or the type of its elements
+ * doesn't match @type.
+ */
+int acpi_dev_get_property_array(struct acpi_device *adev, const char *name,
+ acpi_object_type type,
+ const union acpi_object **obj)
+{
+ const union acpi_object *prop;
+ int ret, i;
+
+ ret = acpi_dev_get_property(adev, name, ACPI_TYPE_PACKAGE, &prop);
+ if (ret)
+ return ret;
+
+ if (type != ACPI_TYPE_ANY) {
+ /* Check that all elements are of correct type. */
+ for (i = 0; i < prop->package.count; i++)
+ if (prop->package.elements[i].type != type)
+ return -EPROTO;
+ }
+ if (obj)
+ *obj = prop;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_get_property_array);
+
+/**
+ * acpi_dev_get_property_reference - returns handle to the referenced object
+ * @adev: ACPI device to get property
+ * @name: Name of the property
+ * @size_prop: Name of the "size" property in referenced object
+ * @index: Index of the reference to return
+ * @args: Location to store the returned reference with optional arguments
+ *
+ * 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 (@size_prop is not %NULL) follow the
+ * reference and check whether or not there is an integer property @size_prop
+ * under the target object and if so, whether or not its value matches the
+ * number of arguments that follow the reference. If there's more than one
+ * reference in the property value package, @index is used to select the one to
+ * return.
+ *
+ * Return: %0 on success, negative error code on failure.
+ */
+int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
+ const char *size_prop, size_t index,
+ struct acpi_reference_args *args)
+{
+ const union acpi_object *element, *end;
+ const union acpi_object *obj;
+ struct acpi_device *device;
+ int ret, idx = 0;
+
+ ret = acpi_dev_get_property(adev, name, ACPI_TYPE_ANY, &obj);
+ if (ret)
+ return ret;
+
+ /*
+ * The simplest case is when the value is a single reference. Just
+ * return that reference then.
+ */
+ if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {
+ if (size_prop || index)
+ return -EINVAL;
+
+ ret = acpi_bus_get_device(obj->reference.handle, &device);
+ if (ret)
+ return ret;
+
+ args->adev = device;
+ args->nargs = 0;
+ return 0;
+ }
+
+ /*
+ * If it is not a single reference, then it is a package of
+ * references followed by number of ints as follows:
+ *
+ * Package () { REF, INT, REF, INT, INT }
+ *
+ * The index argument is then used to determine which reference
+ * the caller wants (along with the arguments).
+ */
+ if (obj->type != ACPI_TYPE_PACKAGE || index >= obj->package.count)
+ return -EPROTO;
+
+ element = obj->package.elements;
+ end = element + obj->package.count;
+
+ 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;
+
+ if (size_prop) {
+ const union acpi_object *prop;
+
+ /*
+ * Find out how many arguments the refenced object
+ * expects by reading its size_prop property.
+ */
+ ret = acpi_dev_get_property(device, size_prop,
+ ACPI_TYPE_INTEGER, &prop);
+ if (ret)
+ return ret;
+
+ nargs = prop->integer.value;
+ if (nargs > MAX_ACPI_REFERENCE_ARGS
+ || element + nargs > end)
+ return -EPROTO;
+
+ /*
+ * Skip to the start of the arguments and verify
+ * that they all are in fact integers.
+ */
+ for (i = 0; i < nargs; i++)
+ if (element[i].type != ACPI_TYPE_INTEGER)
+ return -EPROTO;
+ } else {
+ /* assume following integer elements are all args */
+ for (i = 0; element + i < end; i++) {
+ int type = element[i].type;
+
+ if (type == ACPI_TYPE_INTEGER)
+ nargs++;
+ else if (type == ACPI_TYPE_LOCAL_REFERENCE)
+ break;
+ else
+ return -EPROTO;
+ }
+ }
+
+ if (idx++ == index) {
+ args->adev = device;
+ args->nargs = nargs;
+ for (i = 0; i < nargs; i++)
+ args->args[i] = element[i].integer.value;
+
+ return 0;
+ }
+
+ element += nargs;
+ }
+
+ return -EPROTO;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_get_property_reference);
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff