Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "This time we have some more new material than we used to have during
  the last couple of development cycles.

  The most important part of it to me is the introduction of a unified
  interface for accessing device properties provided by platform
  firmware.  It works with Device Trees and ACPI in a uniform way and
  drivers using it need not worry about where the properties come from
  as long as the platform firmware (either DT or ACPI) makes them
  available.  It covers both devices and "bare" device node objects
  without struct device representation as that turns out to be necessary
  in some cases.  This has been in the works for quite a few months (and
  development cycles) and has been approved by all of the relevant
  maintainers.

  On top of that, some drivers are switched over to the new interface
  (at25, leds-gpio, gpio_keys_polled) and some additional changes are
  made to the core GPIO subsystem to allow device drivers to manipulate
  GPIOs in the "canonical" way on platforms that provide GPIO
  information in their ACPI tables, but don't assign names to GPIO lines
  (in which case the driver needs to do that on the basis of what it
  knows about the device in question).  That also has been approved by
  the GPIO core maintainers and the rfkill driver is now going to use
  it.

  Second is support for hardware P-states in the intel_pstate driver.
  It uses CPUID to detect whether or not the feature is supported by the
  processor in which case it will be enabled by default.  However, it
  can be disabled entirely from the kernel command line if necessary.

  Next is support for a platform firmware interface based on ACPI
  operation regions used by the PMIC (Power Management Integrated
  Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
  That interface is used for manipulating power resources and for
  thermal management: sensor temperature reporting, trip point setting
  and so on.

  Also the ACPI core is now going to support the _DEP configuration
  information in a limited way.  Basically, _DEP it supposed to reflect
  off-the-hierarchy dependencies between devices which may be very
  indirect, like when AML for one device accesses locations in an
  operation region handled by another device's driver (usually, the
  device depended on this way is a serial bus or GPIO controller).  The
  support added this time is sufficient to make the ACPI battery driver
  work on Asus T100A, but it is general enough to be able to cover some
  other use cases in the future.

  Finally, we have a new cpufreq driver for the Loongson1B processor.

  In addition to the above, there are fixes and cleanups all over the
  place as usual and a traditional ACPICA update to a recent upstream
  release.

  As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
  Intel platforms should be able to handle power management of the DMA
  engine correctly, the cpufreq-dt driver should interact with the
  thermal subsystem in a better way and the ACPI backlight driver should
  handle some more corner cases, among other things.

  On top of the ACPICA update there are fixes for race conditions in the
  ACPICA's interrupt handling code which might lead to some random and
  strange looking failures on some systems.

  In the cleanups department the most visible part is the series of
  commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
  option.  That was triggered by a discussion regarding the generic
  power domains code during which we realized that trying to support
  certain combinations of PM config options was painful and not really
  worth it, because nobody would use them in production anyway.  For
  this reason, we decided to make CONFIG_PM_SLEEP select
  CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
  became redundant and CONFIG_PM could be used instead of it.  The
  material here makes that replacement in a major part of the tree, but
  there will be at least one more batch of that in the second part of
  the merge window.

  Specifics:

   - Support for retrieving device properties information from ACPI _DSD
     device configuration objects and a unified device properties
     interface for device drivers (and subsystems) on top of that.  As
     stated above, this works with Device Trees and ACPI and allows
     device drivers to be written in a platform firmware (DT or ACPI)
     agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers are
     now going to use this new interface and the GPIO subsystem is
     additionally modified to allow device drivers to assign names to
     GPIO resources returned by ACPI _CRS objects (in case _DSD is not
     present or does not provide the expected data).  The changes in
     this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
     Lu, and Darren Hart with some fixes from others (Fabio Estevam,
     Geert Uytterhoeven).

   - Support for Hardware Managed Performance States (HWP) as described
     in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
     driver.  CPUID is used to detect whether or not the feature is
     supported by the processor.  If supported, it will be enabled
     automatically unless the intel_pstate=no_hwp switch is present in
     the kernel command line.  From Dirk Brandewie.

   - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).

   - Support for firmware interface based on ACPI operation regions used
     by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
     platforms for power resource control and thermal management (Aaron
     Lu).

   - Limited support for retrieving off-the-hierarchy dependencies
     between devices from ACPI _DEP device configuration objects and
     deferred probing support for the ACPI battery driver based on the
     _DEP information to make that driver work on Asus T100A (Lan
     Tianyu).

   - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).

   - ACPICA update to upstream revision 20141107 which only affects
     tools (Bob Moore).

   - Fixes for race conditions in the ACPICA's interrupt handling code
     and in the ACPI code related to system suspend and resume (Lv Zheng
     and Rafael J Wysocki).

   - ACPI core fix for an RCU-related issue in the ioremap() regions
     management code that slowed down significantly after CPUs had been
     allowed to enter idle states even if they'd had RCU callbakcs
     queued and triggered some problems in certain proprietary graphics
     driver (and elsewhere).  The fix replaces synchronize_rcu() in that
     code with synchronize_rcu_expedited() which makes the issue go
     away.  From Konstantin Khlebnikov.

   - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
     management of the DMA engine included into the LPSS correctly.  The
     problem is that the DMA engine doesn't have ACPI PM support of its
     own and it simply is turned off when the last LPSS device having
     ACPI PM support goes into D3cold.  To work around that, the PM
     domain used by the ACPI LPSS driver is redesigned so at least one
     device with ACPI PM support will be on as long as the DMA engine is
     in use.  From Andy Shevchenko.

   - ACPI backlight driver fix to avoid using it on "Win8-compatible"
     systems where it doesn't work and where it was used by default by
     mistake (Aaron Lu).

   - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
     Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
     Chaugule (mostly related to the upcoming ARM64 support).

   - Intel RAPL (Running Average Power Limit) power capping driver fixes
     and improvements including new processor IDs (Jacob Pan).

   - Generic power domains modification to power up domains after
     attaching devices to them to meet the expectations of device
     drivers and bus types assuming devices to be accessible at probe
     time (Ulf Hansson).

   - Preliminary support for controlling device clocks from the generic
     power domains core code and modifications of the ARM/shmobile
     platform to use that feature (Ulf Hansson).

   - Assorted minor fixes and cleanups of the generic power domains core
     code (Ulf Hansson, Geert Uytterhoeven).

   - Assorted minor fixes and cleanups of the device clocks control code
     in the PM core (Geert Uytterhoeven, Grygorii Strashko).

   - Consolidation of device power management Kconfig options by making
     CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
     which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
     is the first batch of the changes needed for this purpose.

   - Core device runtime power management support code cleanup related
     to the execution of callbacks (Andrzej Hajda).

   - cpuidle ARM support improvements (Lorenzo Pieralisi).

   - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
     new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
     Bartlomiej Zolnierkiewicz).

   - New cpufreq driver callback (->ready) to be executed when the
     cpufreq core is ready to use a given policy object and cpufreq-dt
     driver modification to use that callback for cooling device
     registration (Viresh Kumar).

   - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
     Geboski, Tomeu Vizoso).

   - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
     cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
     Stefan Wahren, Petr Cvek).

   - OPP (Operating Performance Points) framework modification to allow
     OPPs to be removed too and update of a few cpufreq drivers
     (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
     during initialization) on driver removal (Viresh Kumar).

   - Hibernation core fixes and cleanups (Tina Ruchandani and Markus
     Elfring).

   - PM Kconfig fix related to CPU power management (Pankaj Dubey).

   - cpupower tool fix (Prarit Bhargava)"

* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tools: cpupower: fix return checks for sysfs_get_idlestate_count()
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  leds: leds-gpio: Fix multiple instances registration without 'label' property
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  ...

1 files changed, 551 insertions, 0 deletions

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
new file mode 100644
index 000000000000..0d083736e25b
--- /dev/null
+++ b/drivers/acpi/property.c
@@ -0,0 +1,551 @@
+/*
+ * 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;
+}