123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206 |
- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Dell WMI descriptor driver
- *
- * Copyright (C) 2017 Dell Inc. All Rights Reserved.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #include <linux/acpi.h>
- #include <linux/list.h>
- #include <linux/module.h>
- #include <linux/wmi.h>
- #include "dell-wmi-descriptor.h"
- #define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
- struct descriptor_priv {
- struct list_head list;
- u32 interface_version;
- u32 size;
- u32 hotfix;
- };
- static int descriptor_valid = -EPROBE_DEFER;
- static LIST_HEAD(wmi_list);
- static DEFINE_MUTEX(list_mutex);
- int dell_wmi_get_descriptor_valid(void)
- {
- if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID))
- return -ENODEV;
- return descriptor_valid;
- }
- EXPORT_SYMBOL_GPL(dell_wmi_get_descriptor_valid);
- bool dell_wmi_get_interface_version(u32 *version)
- {
- struct descriptor_priv *priv;
- bool ret = false;
- mutex_lock(&list_mutex);
- priv = list_first_entry_or_null(&wmi_list,
- struct descriptor_priv,
- list);
- if (priv) {
- *version = priv->interface_version;
- ret = true;
- }
- mutex_unlock(&list_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(dell_wmi_get_interface_version);
- bool dell_wmi_get_size(u32 *size)
- {
- struct descriptor_priv *priv;
- bool ret = false;
- mutex_lock(&list_mutex);
- priv = list_first_entry_or_null(&wmi_list,
- struct descriptor_priv,
- list);
- if (priv) {
- *size = priv->size;
- ret = true;
- }
- mutex_unlock(&list_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(dell_wmi_get_size);
- bool dell_wmi_get_hotfix(u32 *hotfix)
- {
- struct descriptor_priv *priv;
- bool ret = false;
- mutex_lock(&list_mutex);
- priv = list_first_entry_or_null(&wmi_list,
- struct descriptor_priv,
- list);
- if (priv) {
- *hotfix = priv->hotfix;
- ret = true;
- }
- mutex_unlock(&list_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(dell_wmi_get_hotfix);
- /*
- * Descriptor buffer is 128 byte long and contains:
- *
- * Name Offset Length Value
- * Vendor Signature 0 4 "DELL"
- * Object Signature 4 4 " WMI"
- * WMI Interface Version 8 4 <version>
- * WMI buffer length 12 4 <length>
- * WMI hotfix number 16 4 <hotfix>
- */
- static int dell_wmi_descriptor_probe(struct wmi_device *wdev,
- const void *context)
- {
- union acpi_object *obj = NULL;
- struct descriptor_priv *priv;
- u32 *buffer;
- int ret;
- obj = wmidev_block_query(wdev, 0);
- if (!obj) {
- dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n");
- ret = -EIO;
- goto out;
- }
- if (obj->type != ACPI_TYPE_BUFFER) {
- dev_err(&wdev->dev, "Dell descriptor has wrong type\n");
- ret = -EINVAL;
- descriptor_valid = ret;
- goto out;
- }
- /* Although it's not technically a failure, this would lead to
- * unexpected behavior
- */
- if (obj->buffer.length != 128) {
- dev_err(&wdev->dev,
- "Dell descriptor buffer has unexpected length (%d)\n",
- obj->buffer.length);
- ret = -EINVAL;
- descriptor_valid = ret;
- goto out;
- }
- buffer = (u32 *)obj->buffer.pointer;
- if (strncmp(obj->string.pointer, "DELL WMI", 8) != 0) {
- dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n",
- buffer);
- ret = -EINVAL;
- descriptor_valid = ret;
- goto out;
- }
- descriptor_valid = 0;
- if (buffer[2] != 0 && buffer[2] != 1)
- dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%lu)\n",
- (unsigned long) buffer[2]);
- priv = devm_kzalloc(&wdev->dev, sizeof(struct descriptor_priv),
- GFP_KERNEL);
- if (!priv) {
- ret = -ENOMEM;
- goto out;
- }
- priv->interface_version = buffer[2];
- priv->size = buffer[3];
- priv->hotfix = buffer[4];
- ret = 0;
- dev_set_drvdata(&wdev->dev, priv);
- mutex_lock(&list_mutex);
- list_add_tail(&priv->list, &wmi_list);
- mutex_unlock(&list_mutex);
- dev_dbg(&wdev->dev, "Detected Dell WMI interface version %lu, buffer size %lu, hotfix %lu\n",
- (unsigned long) priv->interface_version,
- (unsigned long) priv->size,
- (unsigned long) priv->hotfix);
- out:
- kfree(obj);
- return ret;
- }
- static int dell_wmi_descriptor_remove(struct wmi_device *wdev)
- {
- struct descriptor_priv *priv = dev_get_drvdata(&wdev->dev);
- mutex_lock(&list_mutex);
- list_del(&priv->list);
- mutex_unlock(&list_mutex);
- return 0;
- }
- static const struct wmi_device_id dell_wmi_descriptor_id_table[] = {
- { .guid_string = DELL_WMI_DESCRIPTOR_GUID },
- { },
- };
- static struct wmi_driver dell_wmi_descriptor_driver = {
- .driver = {
- .name = "dell-wmi-descriptor",
- },
- .probe = dell_wmi_descriptor_probe,
- .remove = dell_wmi_descriptor_remove,
- .id_table = dell_wmi_descriptor_id_table,
- };
- module_wmi_driver(dell_wmi_descriptor_driver);
- MODULE_DEVICE_TABLE(wmi, dell_wmi_descriptor_id_table);
- MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
- MODULE_DESCRIPTION("Dell WMI descriptor driver");
- MODULE_LICENSE("GPL");
|