[mirror_ubuntu-jammy-kernel.git] / drivers / acpi / property.c

/*
 * 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);
Commit	Line	Data
ffdcd955 MW	1	/*
	2	* ACPI device specific properties support.
	3	*
	4	* Copyright (C) 2014, Intel Corporation
	5	* All rights reserved.
	6	*
	7	* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
	8	* Darren Hart <dvhart@linux.intel.com>
	9	* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/acpi.h>
	17	#include <linux/device.h>
	18	#include <linux/export.h>
	19
	20	#include "internal.h"
	21
	22	/* ACPI _DSD device properties UUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
	23	static const u8 prp_uuid[16] = {
	24	0x14, 0xd8, 0xff, 0xda, 0xba, 0x6e, 0x8c, 0x4d,
	25	0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01
	26	};
	27
	28	static bool acpi_property_value_ok(const union acpi_object *value)
	29	{
	30	int j;
	31
	32	/*
	33	* The value must be an integer, a string, a reference, or a package
	34	* whose every element must be an integer, a string, or a reference.
	35	*/
	36	switch (value->type) {
	37	case ACPI_TYPE_INTEGER:
	38	case ACPI_TYPE_STRING:
	39	case ACPI_TYPE_LOCAL_REFERENCE:
	40	return true;
	41
	42	case ACPI_TYPE_PACKAGE:
	43	for (j = 0; j < value->package.count; j++)
	44	switch (value->package.elements[j].type) {
	45	case ACPI_TYPE_INTEGER:
	46	case ACPI_TYPE_STRING:
	47	case ACPI_TYPE_LOCAL_REFERENCE:
	48	continue;
	49
	50	default:
	51	return false;
	52	}
	53
	54	return true;
	55	}
	56	return false;
	57	}
	58
	59	static bool acpi_properties_format_valid(const union acpi_object *properties)
	60	{
	61	int i;
	62
	63	for (i = 0; i < properties->package.count; i++) {
	64	const union acpi_object *property;
65
66	property = &properties->package.elements[i];
67	/*
68	* Only two elements allowed, the first one must be a string and
69	* the second one has to satisfy certain conditions.
70	*/
71	if (property->package.count != 2
72	\|\| property->package.elements[0].type != ACPI_TYPE_STRING
73	\|\| !acpi_property_value_ok(&property->package.elements[1]))
74	return false;
75	}
76	return true;
77	}
78
79	void acpi_init_properties(struct acpi_device *adev)
80	{
81	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
82	const union acpi_object *desc;
83	acpi_status status;
84	int i;
85
86	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
87	ACPI_TYPE_PACKAGE);
88	if (ACPI_FAILURE(status))
89	return;
90
91	desc = buf.pointer;
92	if (desc->package.count % 2)
93	goto fail;
94
95	/* Look for the device properties UUID. */
96	for (i = 0; i < desc->package.count; i += 2) {
97	const union acpi_object uuid, properties;
98
99	uuid = &desc->package.elements[i];
100	properties = &desc->package.elements[i + 1];
101
102	/*
103	* The first element must be a UUID and the second one must be
104	* a package.
105	*/
106	if (uuid->type != ACPI_TYPE_BUFFER \|\| uuid->buffer.length != 16
107	\|\| properties->type != ACPI_TYPE_PACKAGE)
108	break;
109
110	if (memcmp(uuid->buffer.pointer, prp_uuid, sizeof(prp_uuid)))
111	continue;
112
113	/*
114	* We found the matching UUID. Now validate the format of the
115	* package immediately following it.
116	*/
117	if (!acpi_properties_format_valid(properties))
118	break;
119
120	adev->data.pointer = buf.pointer;
121	adev->data.properties = properties;
122	return;
123	}
124
125	fail:
126	dev_warn(&adev->dev, "Returned _DSD data is not valid, skipping\n");
127	ACPI_FREE(buf.pointer);
128	}
129
130	void acpi_free_properties(struct acpi_device *adev)
131	{
132	ACPI_FREE((void *)adev->data.pointer);
133	adev->data.pointer = NULL;
134	adev->data.properties = NULL;
135	}
136
137	/**
138	* acpi_dev_get_property - return an ACPI property with given name
139	* @adev: ACPI device to get property
140	* @name: Name of the property
141	* @type: Expected property type
142	* @obj: Location to store the property value (if not %NULL)
143	*
144	* Look up a property with @name and store a pointer to the resulting ACPI
145	* object at the location pointed to by @obj if found.
146	*
147	* Callers must not attempt to free the returned objects. These objects will be
148	* freed by the ACPI core automatically during the removal of @adev.
149	*
150	* Return: %0 if property with @name has been found (success),
151	* %-EINVAL if the arguments are invalid,
152	* %-ENODATA if the property doesn't exist,
153	* %-EPROTO if the property value type doesn't match @type.
154	*/
155	int acpi_dev_get_property(struct acpi_device adev, const char name,
156	acpi_object_type type, const union acpi_object **obj)
157	{
158	const union acpi_object *properties;
159	int i;
160
161	if (!adev \|\| !name)
162	return -EINVAL;
163
164	if (!adev->data.pointer \|\| !adev->data.properties)
165	return -ENODATA;
166
167	properties = adev->data.properties;
168	for (i = 0; i < properties->package.count; i++) {
169	const union acpi_object propname, propvalue;
170	const union acpi_object *property;
171
172	property = &properties->package.elements[i];
173
174	propname = &property->package.elements[0];
175	propvalue = &property->package.elements[1];
176
177	if (!strcmp(name, propname->string.pointer)) {
178	if (type != ACPI_TYPE_ANY && propvalue->type != type)
179	return -EPROTO;
180	else if (obj)
181	*obj = propvalue;
182
183	return 0;
184	}
185	}
186	return -ENODATA;
187	}
188	EXPORT_SYMBOL_GPL(acpi_dev_get_property);
189
190	/**
191	* acpi_dev_get_property_array - return an ACPI array property with given name
192	* @adev: ACPI device to get property
193	* @name: Name of the property
194	* @type: Expected type of array elements
195	* @obj: Location to store a pointer to the property value (if not NULL)
196	*
197	* Look up an array property with @name and store a pointer to the resulting
198	* ACPI object at the location pointed to by @obj if found.
199	*
200	* Callers must not attempt to free the returned objects. Those objects will be
201	* freed by the ACPI core automatically during the removal of @adev.
202	*
203	* Return: %0 if array property (package) with @name has been found (success),
204	* %-EINVAL if the arguments are invalid,
205	* %-ENODATA if the property doesn't exist,
206	* %-EPROTO if the property is not a package or the type of its elements
207	* doesn't match @type.
208	*/
209	int acpi_dev_get_property_array(struct acpi_device adev, const char name,
210	acpi_object_type type,
211	const union acpi_object **obj)
212	{
213	const union acpi_object *prop;
214	int ret, i;
215
216	ret = acpi_dev_get_property(adev, name, ACPI_TYPE_PACKAGE, &prop);
217	if (ret)
218	return ret;
219
220	if (type != ACPI_TYPE_ANY) {
221	/* Check that all elements are of correct type. */
222	for (i = 0; i < prop->package.count; i++)
223	if (prop->package.elements[i].type != type)
224	return -EPROTO;
225	}
226	if (obj)
227	*obj = prop;
228
229	return 0;
230	}
231	EXPORT_SYMBOL_GPL(acpi_dev_get_property_array);
232
233	/**
234	* acpi_dev_get_property_reference - returns handle to the referenced object
235	* @adev: ACPI device to get property
236	* @name: Name of the property
237	* @size_prop: Name of the "size" property in referenced object
238	* @index: Index of the reference to return
239	* @args: Location to store the returned reference with optional arguments
240	*
241	* Find property with @name, verifify that it is a package containing at least
242	* one object reference and if so, store the ACPI device object pointer to the
243	* target object in @args->adev.
244	*
245	* If the reference includes arguments (@size_prop is not %NULL) follow the
246	* reference and check whether or not there is an integer property @size_prop
247	* under the target object and if so, whether or not its value matches the
248	* number of arguments that follow the reference. If there's more than one
249	* reference in the property value package, @index is used to select the one to
250	* return.
251	*
252	* Return: %0 on success, negative error code on failure.
253	*/
254	int acpi_dev_get_property_reference(struct acpi_device adev, const char name,
255	const char *size_prop, size_t index,
256	struct acpi_reference_args *args)
257	{
258	const union acpi_object element, end;
259	const union acpi_object *obj;
260	struct acpi_device *device;
261	int ret, idx = 0;
262
263	ret = acpi_dev_get_property(adev, name, ACPI_TYPE_ANY, &obj);
264	if (ret)
265	return ret;
266
267	/*
268	* The simplest case is when the value is a single reference. Just
269	* return that reference then.
270	*/
271	if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {
272	if (size_prop \|\| index)
273	return -EINVAL;
274
275	ret = acpi_bus_get_device(obj->reference.handle, &device);
276	if (ret)
277	return ret;
278
279	args->adev = device;
280	args->nargs = 0;
281	return 0;
282	}
283
284	/*
285	* If it is not a single reference, then it is a package of
286	* references followed by number of ints as follows:
287	*
288	* Package () { REF, INT, REF, INT, INT }
289	*
290	* The index argument is then used to determine which reference
291	* the caller wants (along with the arguments).
292	*/
293	if (obj->type != ACPI_TYPE_PACKAGE \|\| index >= obj->package.count)
294	return -EPROTO;
295
296	element = obj->package.elements;
297	end = element + obj->package.count;
298
299	while (element < end) {
300	u32 nargs, i;
301
302	if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
303	return -EPROTO;
304
305	ret = acpi_bus_get_device(element->reference.handle, &device);
306	if (ret)
307	return -ENODEV;
308
309	element++;
310	nargs = 0;
311
312	if (size_prop) {
313	const union acpi_object *prop;
314
315	/*
316	* Find out how many arguments the refenced object
317	* expects by reading its size_prop property.
318	*/
319	ret = acpi_dev_get_property(device, size_prop,
320	ACPI_TYPE_INTEGER, &prop);
321	if (ret)
322	return ret;
323
324	nargs = prop->integer.value;
325	if (nargs > MAX_ACPI_REFERENCE_ARGS
326	\|\| element + nargs > end)
327	return -EPROTO;
328
329	/*
330	* Skip to the start of the arguments and verify
331	* that they all are in fact integers.
332	*/
333	for (i = 0; i < nargs; i++)
334	if (element[i].type != ACPI_TYPE_INTEGER)
335	return -EPROTO;
336	} else {
337	/* assume following integer elements are all args */
338	for (i = 0; element + i < end; i++) {
339	int type = element[i].type;
340
341	if (type == ACPI_TYPE_INTEGER)
342	nargs++;
343	else if (type == ACPI_TYPE_LOCAL_REFERENCE)
344	break;
345	else
346	return -EPROTO;
347	}
348	}
349
350	if (idx++ == index) {
351	args->adev = device;
352	args->nargs = nargs;
353	for (i = 0; i < nargs; i++)
354	args->args[i] = element[i].integer.value;
355
356	return 0;
357	}
358
359	element += nargs;
360	}
361
362	return -EPROTO;
363	}
364	EXPORT_SYMBOL_GPL(acpi_dev_get_property_reference);