1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Functions corresponding to string type attributes under BIOS String GUID for use with
  4 * dell-wmi-sysman
  5 *
  6 *  Copyright (c) 2020 Dell Inc.
  7 */
  8
  9#include "dell-wmi-sysman.h"
 10
 11enum string_properties {MIN_LEN = 6, MAX_LEN};
 12
 13get_instance_id(str);
 14
 15static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
 16{
 17	int instance_id = get_str_instance_id(kobj);
 18	union acpi_object *obj;
 19	ssize_t ret;
 20
 21	if (instance_id < 0)
 22		return -EIO;
 23
 24	/* need to use specific instance_id and guid combination to get right data */
 25	obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
 26	if (!obj)
 27		return -EIO;
 28	if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING) {
 29		kfree(obj);
 30		return -EINVAL;
 31	}
 32	ret = snprintf(buf, PAGE_SIZE, "%s\n", obj->package.elements[CURRENT_VAL].string.pointer);
 33	kfree(obj);
 34	return ret;
 35}
 36
 37/**
 38 * validate_str_input() - Validate input of current_value against min and max lengths
 39 * @instance_id: The instance on which input is validated
 40 * @buf: Input value
 41 */
 42static int validate_str_input(int instance_id, const char *buf)
 43{
 44	int in_len = strlen(buf);
 45
 46	if ((in_len < wmi_priv.str_data[instance_id].min_length) ||
 47			(in_len > wmi_priv.str_data[instance_id].max_length))
 48		return -EINVAL;
 49
 50	return 0;
 51}
 52
 53attribute_s_property_show(display_name_language_code, str);
 54static struct kobj_attribute str_displ_langcode =
 55		__ATTR_RO(display_name_language_code);
 56
 57attribute_s_property_show(display_name, str);
 58static struct kobj_attribute str_displ_name =
 59		__ATTR_RO(display_name);
 60
 61attribute_s_property_show(default_value, str);
 62static struct kobj_attribute str_default_val =
 63		__ATTR_RO(default_value);
 64
 65attribute_property_store(current_value, str);
 66static struct kobj_attribute str_current_val =
 67		__ATTR_RW_MODE(current_value, 0600);
 68
 69attribute_s_property_show(dell_modifier, str);
 70static struct kobj_attribute str_modifier =
 71		__ATTR_RO(dell_modifier);
 72
 73attribute_n_property_show(min_length, str);
 74static struct kobj_attribute str_min_length =
 75		__ATTR_RO(min_length);
 76
 77attribute_n_property_show(max_length, str);
 78static struct kobj_attribute str_max_length =
 79		__ATTR_RO(max_length);
 80
 81static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
 82			 char *buf)
 83{
 84	return sprintf(buf, "string\n");
 85}
 86static struct kobj_attribute str_type =
 87	__ATTR_RO(type);
 88
 89static struct attribute *str_attrs[] = {
 90	&str_displ_langcode.attr,
 91	&str_displ_name.attr,
 92	&str_default_val.attr,
 93	&str_current_val.attr,
 94	&str_modifier.attr,
 95	&str_min_length.attr,
 96	&str_max_length.attr,
 97	&str_type.attr,
 98	NULL,
 99};
100
101static const struct attribute_group str_attr_group = {
102	.attrs = str_attrs,
103};
104
105int alloc_str_data(void)
106{
107	int ret = 0;
108
109	wmi_priv.str_instances_count = get_instance_count(DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
110	wmi_priv.str_data = kcalloc(wmi_priv.str_instances_count,
111					sizeof(struct str_data), GFP_KERNEL);
112	if (!wmi_priv.str_data) {
113		wmi_priv.str_instances_count = 0;
114		ret = -ENOMEM;
115	}
116	return ret;
117}
118
119/**
120 * populate_str_data() - Populate all properties of an instance under string attribute
121 * @str_obj: ACPI object with string data
122 * @instance_id: The instance to enumerate
123 * @attr_name_kobj: The parent kernel object
124 */
125int populate_str_data(union acpi_object *str_obj, int instance_id, struct kobject *attr_name_kobj)
126{
127	wmi_priv.str_data[instance_id].attr_name_kobj = attr_name_kobj;
128	if (check_property_type(str, ATTR_NAME, ACPI_TYPE_STRING))
129		return -EINVAL;
130	strlcpy_attr(wmi_priv.str_data[instance_id].attribute_name,
131		     str_obj[ATTR_NAME].string.pointer);
132	if (check_property_type(str, DISPL_NAME_LANG_CODE, ACPI_TYPE_STRING))
133		return -EINVAL;
134	strlcpy_attr(wmi_priv.str_data[instance_id].display_name_language_code,
135		     str_obj[DISPL_NAME_LANG_CODE].string.pointer);
136	if (check_property_type(str, DISPLAY_NAME, ACPI_TYPE_STRING))
137		return -EINVAL;
138	strlcpy_attr(wmi_priv.str_data[instance_id].display_name,
139		     str_obj[DISPLAY_NAME].string.pointer);
140	if (check_property_type(str, DEFAULT_VAL, ACPI_TYPE_STRING))
141		return -EINVAL;
142	strlcpy_attr(wmi_priv.str_data[instance_id].default_value,
143		     str_obj[DEFAULT_VAL].string.pointer);
144	if (check_property_type(str, MODIFIER, ACPI_TYPE_STRING))
145		return -EINVAL;
146	strlcpy_attr(wmi_priv.str_data[instance_id].dell_modifier,
147		     str_obj[MODIFIER].string.pointer);
148	if (check_property_type(str, MIN_LEN, ACPI_TYPE_INTEGER))
149		return -EINVAL;
150	wmi_priv.str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
151	if (check_property_type(str, MAX_LEN, ACPI_TYPE_INTEGER))
152		return -EINVAL;
153	wmi_priv.str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
154
155	return sysfs_create_group(attr_name_kobj, &str_attr_group);
156}
157
158/**
159 * exit_str_attributes() - Clear all attribute data
160 *
161 * Clears all data allocated for this group of attributes
162 */
163void exit_str_attributes(void)
164{
165	int instance_id;
166
167	for (instance_id = 0; instance_id < wmi_priv.str_instances_count; instance_id++) {
168		if (wmi_priv.str_data[instance_id].attr_name_kobj)
169			sysfs_remove_group(wmi_priv.str_data[instance_id].attr_name_kobj,
170								&str_attr_group);
171	}
172	wmi_priv.str_instances_count = 0;
173
174	kfree(wmi_priv.str_data);
175	wmi_priv.str_data = NULL;
176}