blob: 0d083736e25babf920140d9b0c88a84b47d6d729 [file] [log] [blame]
/*
* 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;
}
static void acpi_init_of_compatible(struct acpi_device *adev)
{
const union acpi_object *of_compatible;
struct acpi_hardware_id *hwid;
bool acpi_of = false;
int ret;
/*
* Check if the special PRP0001 ACPI ID is present and in that
* case we fill in Device Tree compatible properties for this
* device.
*/
list_for_each_entry(hwid, &adev->pnp.ids, list) {
if (!strcmp(hwid->id, "PRP0001")) {
acpi_of = true;
break;
}
}
if (!acpi_of)
return;
ret = acpi_dev_get_property_array(adev, "compatible", ACPI_TYPE_STRING,
&of_compatible);
if (ret) {
ret = acpi_dev_get_property(adev, "compatible",
ACPI_TYPE_STRING, &of_compatible);
if (ret) {
acpi_handle_warn(adev->handle,
"PRP0001 requires compatible property\n");
return;
}
}
adev->data.of_compatible = of_compatible;
}
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;
acpi_init_of_compatible(adev);
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.of_compatible = NULL;
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
* @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, 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.
*
* Return: %0 on success, negative error code on failure.
*/
int acpi_dev_get_property_reference(struct acpi_device *adev,
const char *name, 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 (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;
/* 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);
int acpi_dev_prop_get(struct acpi_device *adev, const char *propname,
void **valptr)
{
return acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
(const union acpi_object **)valptr);
}
int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
enum dev_prop_type proptype, void *val)
{
const union acpi_object *obj;
int ret;
if (!val)
return -EINVAL;
if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_INTEGER, &obj);
if (ret)
return ret;
switch (proptype) {
case DEV_PROP_U8:
if (obj->integer.value > U8_MAX)
return -EOVERFLOW;
*(u8 *)val = obj->integer.value;
break;
case DEV_PROP_U16:
if (obj->integer.value > U16_MAX)
return -EOVERFLOW;
*(u16 *)val = obj->integer.value;
break;
case DEV_PROP_U32:
if (obj->integer.value > U32_MAX)
return -EOVERFLOW;
*(u32 *)val = obj->integer.value;
break;
default:
*(u64 *)val = obj->integer.value;
break;
}
} else if (proptype == DEV_PROP_STRING) {
ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_STRING, &obj);
if (ret)
return ret;
*(char **)val = obj->string.pointer;
} else {
ret = -EINVAL;
}
return ret;
}
static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val,
size_t nval)
{
int i;
for (i = 0; i < nval; i++) {
if (items[i].type != ACPI_TYPE_INTEGER)
return -EPROTO;
if (items[i].integer.value > U8_MAX)
return -EOVERFLOW;
val[i] = items[i].integer.value;
}
return 0;
}
static int acpi_copy_property_array_u16(const union acpi_object *items,
u16 *val, size_t nval)
{
int i;
for (i = 0; i < nval; i++) {
if (items[i].type != ACPI_TYPE_INTEGER)
return -EPROTO;
if (items[i].integer.value > U16_MAX)
return -EOVERFLOW;
val[i] = items[i].integer.value;
}
return 0;
}
static int acpi_copy_property_array_u32(const union acpi_object *items,
u32 *val, size_t nval)
{
int i;
for (i = 0; i < nval; i++) {
if (items[i].type != ACPI_TYPE_INTEGER)
return -EPROTO;
if (items[i].integer.value > U32_MAX)
return -EOVERFLOW;
val[i] = items[i].integer.value;
}
return 0;
}
static int acpi_copy_property_array_u64(const union acpi_object *items,
u64 *val, size_t nval)
{
int i;
for (i = 0; i < nval; i++) {
if (items[i].type != ACPI_TYPE_INTEGER)
return -EPROTO;
val[i] = items[i].integer.value;
}
return 0;
}
static int acpi_copy_property_array_string(const union acpi_object *items,
char **val, size_t nval)
{
int i;
for (i = 0; i < nval; i++) {
if (items[i].type != ACPI_TYPE_STRING)
return -EPROTO;
val[i] = items[i].string.pointer;
}
return 0;
}
int acpi_dev_prop_read(struct acpi_device *adev, const char *propname,
enum dev_prop_type proptype, void *val, size_t nval)
{
const union acpi_object *obj;
const union acpi_object *items;
int ret;
if (val && nval == 1) {
ret = acpi_dev_prop_read_single(adev, propname, proptype, val);
if (!ret)
return ret;
}
ret = acpi_dev_get_property_array(adev, propname, ACPI_TYPE_ANY, &obj);
if (ret)
return ret;
if (!val)
return obj->package.count;
else if (nval <= 0)
return -EINVAL;
if (nval > obj->package.count)
return -EOVERFLOW;
items = obj->package.elements;
switch (proptype) {
case DEV_PROP_U8:
ret = acpi_copy_property_array_u8(items, (u8 *)val, nval);
break;
case DEV_PROP_U16:
ret = acpi_copy_property_array_u16(items, (u16 *)val, nval);
break;
case DEV_PROP_U32:
ret = acpi_copy_property_array_u32(items, (u32 *)val, nval);
break;
case DEV_PROP_U64:
ret = acpi_copy_property_array_u64(items, (u64 *)val, nval);
break;
case DEV_PROP_STRING:
ret = acpi_copy_property_array_string(items, (char **)val, nval);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}