diff options
Diffstat (limited to 'drivers/acpi/property.c')
| -rw-r--r-- | drivers/acpi/property.c | 551 |
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; +} |