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 
11 enum string_properties {MIN_LEN = 6, MAX_LEN};
12 
13 get_instance_id(str);
14 
15 static 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  */
42 static 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 
53 attribute_s_property_show(display_name_language_code, str);
54 static struct kobj_attribute str_displ_langcode =
55 		__ATTR_RO(display_name_language_code);
56 
57 attribute_s_property_show(display_name, str);
58 static struct kobj_attribute str_displ_name =
59 		__ATTR_RO(display_name);
60 
61 attribute_s_property_show(default_value, str);
62 static struct kobj_attribute str_default_val =
63 		__ATTR_RO(default_value);
64 
65 attribute_property_store(current_value, str);
66 static struct kobj_attribute str_current_val =
67 		__ATTR_RW_MODE(current_value, 0600);
68 
69 attribute_s_property_show(dell_modifier, str);
70 static struct kobj_attribute str_modifier =
71 		__ATTR_RO(dell_modifier);
72 
73 attribute_n_property_show(min_length, str);
74 static struct kobj_attribute str_min_length =
75 		__ATTR_RO(min_length);
76 
77 attribute_n_property_show(max_length, str);
78 static struct kobj_attribute str_max_length =
79 		__ATTR_RO(max_length);
80 
81 static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
82 			 char *buf)
83 {
84 	return sprintf(buf, "string\n");
85 }
86 static struct kobj_attribute str_type =
87 	__ATTR_RO(type);
88 
89 static 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 
101 static const struct attribute_group str_attr_group = {
102 	.attrs = str_attrs,
103 };
104 
105 int 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 integer data
122  * @instance_id: The instance to enumerate
123  * @attr_name_kobj: The parent kernel object
124  */
125 int 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 	strlcpy_attr(wmi_priv.str_data[instance_id].attribute_name,
129 		     str_obj[ATTR_NAME].string.pointer);
130 	strlcpy_attr(wmi_priv.str_data[instance_id].display_name_language_code,
131 		     str_obj[DISPL_NAME_LANG_CODE].string.pointer);
132 	strlcpy_attr(wmi_priv.str_data[instance_id].display_name,
133 		     str_obj[DISPLAY_NAME].string.pointer);
134 	strlcpy_attr(wmi_priv.str_data[instance_id].default_value,
135 		     str_obj[DEFAULT_VAL].string.pointer);
136 	strlcpy_attr(wmi_priv.str_data[instance_id].dell_modifier,
137 		     str_obj[MODIFIER].string.pointer);
138 	wmi_priv.str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
139 	wmi_priv.str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
140 
141 	return sysfs_create_group(attr_name_kobj, &str_attr_group);
142 }
143 
144 /**
145  * exit_str_attributes() - Clear all attribute data
146  *
147  * Clears all data allocated for this group of attributes
148  */
149 void exit_str_attributes(void)
150 {
151 	int instance_id;
152 
153 	for (instance_id = 0; instance_id < wmi_priv.str_instances_count; instance_id++) {
154 		if (wmi_priv.str_data[instance_id].attr_name_kobj)
155 			sysfs_remove_group(wmi_priv.str_data[instance_id].attr_name_kobj,
156 								&str_attr_group);
157 	}
158 	wmi_priv.str_instances_count = 0;
159 
160 	kfree(wmi_priv.str_data);
161 	wmi_priv.str_data = NULL;
162 }
163