drivers/platform/x86/dell-wmi-sysman/string-attributes.c

   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         kfree(wmi_priv.str_data);
 159 }